The irony is that fiber optic cable is actually cheaper to manufacture than coax. They just charge through the nose for it because it’s marketed as higher-tech.
The main reason is that its much harder to terminate for networking than coax - if its a custom run and not a prefab you're going to pay to have it cut and polished and that racks the price up significantly.
Security camera enthusiast here (my "home" CCTV system is 80+ cameras strong and my collection is 500+ cameras and 120+ bits of control equipment) TVI and CVI also are able to pass audio and control signals both ways for configuration of the camera and PTZ control from thr DVR (provided it supports it) Most of those AHD DVR machines are basically a RISC V / ARM SoC with a hardware accelerated video processing unit. Some are on the same chip. Thr good ones have a dedicated video chip that communicates with the microprocessor via PCI-E. I run all of my CVI cameras over twisted pair cable and provided there is a good converter on the receiving end, the video is surprisingly sharp. TVI cameras I run over coaxes (there slight differences and TVI is slightly more sensitive but the overall picture is a tad bit nicer in my opinion) After buying a lot of TVI cameras I found the best one of them all is probably the HiWatch (Hikvision outside Europe) DS-T226 so it might be worth a look at that to see the really high end TVI there is.
@@CathodeRayDude I was wondering when you were going to go down the surveillance rabbit hole. Lots of boutique solutions for boutique circumstances in the industry. The HD-TVI cameras more or less exist because of all the old coax that's still in these buildings from prior runs. A new system would just be POE because you can go even farther than the numbers you quoted for POE in your video. You use an Ethernet to Fibre media converters to go farther. A media converter will get you 600 additional yards for less than $100. It looks like this: Camera -> POE Injector -> Media Converter -> Network (which may or may not have a corresponding converter back on the other side depending on your hardware). Then there's the wireless meshnet stuff some dudes are doing on their ranches using small radio towers to network wireless trail cameras. There's a lot of really cool tech in use at modern ranches.
To the point about graceful signal degradation in digital: This actually does exist, and the only company that I know who does it got their start in AHD security cameras. Divimath, who make HDZero FPV drone racing transceivers, have their signal processors accept basically any data and display it uncompressed, as-is, so while the picture is digital (some kind of JPEG-like DCT compression) it fuzzes and fades very similarly to analog.
Ah, neat! It does seem like the goal of a standard video codec is balancing compression with quality, but ignoring robustness for the most part. Data between key frames is so dependent on being intact (since they use complicated methods to store differences between frames rather than whole images) that missing a small part can destroy the whole image between the key frames. So with data storage and transmission being less of an issue, it makes sense for there to be a market for more robust codecs in certain situations. Too bad it's too late for DTV.
............bad news, it says coax? but in reality, it is 3 non shielded wires, red yellow and ground if you dont deal with security cameras you would never encounter this crappy cable that claims to be coax they also abuse "poe" cables similar, it isnt an actual ethernet cable, it is the same cheap 3 wire system the coax uses!!
I always thought it was HDSDI (and I'm pretty sure some of the higher end ones are). HDSDI is the same digital data as HDMI, but combined into one serial stream, rather than 4 parallel streams, and with appropriate cable drivers to go long distances over RG-6 type cable (and even further if you use better speced cable). You can get converters from HDMI to HDSDI and HDSDI back to HDMI for not too much money on amazon. And that's the retail price - if you're buying the chipsets in bulk for manufacturing cameras, they're basically dirt cheap.
@@gorak9000 Before HD-SDI you had SDI. I won't be too surprised if that standard accepted signals way beyond the originally intended limits as technology was progressing but a new standard wasn't fully standardised or even accepted by the industry yet. The big difference with HD-SDI is that it usually bypasses all image-processing circuitry in a videocamera and outputs raw sensor-data. HDMI sometimes does that too, but considering it's more a consumer-standard, not every camera supports the same data-throughput on HDMI as it does on HD-SDI. Personally, I prefer HD-SDI, as it features a locking connector (BNC), angled connectors are easily obtained, can have a nice thin cable if you only need to go from the camera to an extra monitor, where HDMI-connectors are always bulky, don't lock, are hard to find in angled-positions (and if you do, they always 'angle' the wrong way) and thin cables are very expensive. All the advantages of HD-SDI is also why I make those cables myself. 50 Euro or more for a short cable is just ridiculous. Now if only some manufacturers of monitors would use more standard connectors (ugh ugh... Blackmagic...)
@@weeardguy There's no way SDI accepted signals beyond the SDI spec. SDI was an older standard for uncompressed SD digital video. It ran at the same clock rate as ASI (mpeg transport stream over serial interface). Both of them have a fixed data rate of 270Mbps. ASI uses 188 byte packets, and if the data rate of the transport stream is less than 270Mbps, the unused 188 byte packets spots are filled with "null stuffing packets", but the physical wire is always running at 270Mbps. Similarly for SDI, uncompressed SD video, you basically need the whole 270Mbps to send the video signal (and associated uncompressed digital audio - there's a fixed number of audio channels you can send). Because the physical clock rate on the cable is fixed, there's really no room to "accept signals way beyond the originally intended limits". HD-SDI is basically the same thing, but with a higher clock rate (1.485Gbps) meant to carry uncompressed HD video. There is no ASI-equivalent at 1.485Gbps or any of the higher speeds - ASI still tops out at 270Mbps. There's also 3G-HD-SDI that runs at 2.97Gbps, 6G-HD-SDI that runs at 6Gbps, 12G-HD-SDI that runs at 12Gbps and 24G-HD-SDI that runs at 24Gbps for carrying higher and higher resolutions of 3D, 4K, 4K 3D, 4K HDR, 8K HDR, and beyond. If they wanted to invent a new standard for HD security cameras, I'm not sure why they didn't take ASI and slow it down - put the video encoder in the camera, then you have somewhere between 5-15Mbps of data you need to send back (depending on desired bitrate and video encoding mpg4 vs h.264 vs h.265). They could've taken the 270Mbps of SDI, slowed the clock way down, say by a factor of 10x to 27Mbps, and you'd have more than enough bandwidth to send back 1 encoded HD stream per camera. There's no reason to be sending back uncompressed video down the cable, that's just dumb. I'll bet with a clock speed reduced ASI running at 27Mbps, you could probably send the data back over 2 coat hangers next to each other (or the worst coax imaginable) and it would work just fine. For cost, I see no difference having the video encoder at the camera side, or at the DVR side - seems that it would be the same either way, but at the camera side means you have a lot less data to transmit, so much easier to do over crap cable.
Wow, this was surprisingly interesting. I suppose this explains why the HD video cameras at my work seemingly get analog video artifacts/static rather than digital ones.
That's interesting. No compression, either, I think. So your work cameras would probably represent a snowstorm quite well, where my home cameras have compression artifacts with so much moving detail.
2:20 the dedication in putting the T-MOBILE logo in every single one of your feeds on the monitor is admirable. You didn't do it recursively, so not quite the insane level of dedication one *could* apply to this, but nonetheless, I appreciate the base level of thoroughness!
you just made me realize all my security cameras (that were not installed by me) are not shit, they are just not configured to actually output hd . . .
I found out through an internship that the world of analog CCTV is, was, and always will be surprisingly complex. To think that they had multiplexed pan/tilt/zoom features for dozens of cameras over a single coax cable in the 1980's is incredible.
In the '90s I remember hearing about plans for a stopgap system for consumer use that would stitch digital video onto the sides of a 4:3 analog TV signal to create a widescreen image while remaining backwards compatible with existing TVs. That didn't go anywhere, I guess due to the FCC realizing how lucrative it would be to abandon analog so they could cram multiple digital TV signals into a single transmitter and then sell off the upper UHF channels to mobile phone carriers.
Put "wikipedia palplus" into a decent web search engine. It was briefly used in several European countries. My Sony DHR-1000UK DV cassette deck has the PALplus decoder built in.
And where would the frequencies for that extra bandwidth to carry digital sides come from? Also how would that increase vertical and horizontal resolution in the center?
@@StevenBradford I cannot definitively answer this question but with radio stations in the US there is a certain amount of bandwidth between channels called guard bands. When FM got the addition of HD radio they used a small amount of bandwidth on either side of the channels using a small amount of the guard band for the digital signal. The digital signal also takes significantly less bandwidth so it fits in the guard bands nicely. You can see what this looks like by searching on here for "HD Radio RTL-SDR Decoding vs Analog Radio"
This is fascinating, I thought the "HD" claim on these camera was dubious considering you could clearly see in the photos they were using what looked like a composite cable. It wasn't until I ordered one myself for a project that I was blown away by the quality.
(19:40) the digital formats (HD and SDI) do NOT simply "throw away" the VBI and HBI, they are used for ancillary data, such as control, test signals, and 16 channels of embedded audio.
Yeah i noticed that too. Which is fine especially when you use them at night and have a nice analogish high-gain videopicture with all the artifacts of analog video. Works really reliable which is why i don't really care for these radio transmitting car cams.
@@wwtoonlinkfan My parents' 2020 Toyota Prius backup cam has what appears to be 480i analog video in spite of its recent vintage. Maybe this is related?
@@wrentubes1886 I've seen aftermarket head units with composite inputs, so I wouldn't be surprised if even stock ones used standard 480i/576i or some other composite standard. Really, for a backup camera you don't need highest quality camera anyways, hell, some cars don't even have one.
There are some pretty exciting security cameras out there. I got to play with a prototype 3000x zoom with IR and night vision. We tried seeing how many fingers people were holding up behind a piece of drywall with moderate success.
I was under the impression that the 720p and 1080p "TV" security cameras were a scam, but seems like they're not. Good thing you did mention the stuff they produce is not ntsc per se, and they need a dvr. Really cool video!
Did not expect to watch a 30 minute video about analog HD signals, something I had no prior interest or knowledge of until now. Very informative, excellent presentation, overall great work. You got a new sub out of me.
Working at a lawfim, I hate finding codecs for surveillance systems when needing to do editing. The worst is when the video player that the hardware requires for playback doesn't supply a way to export the video to a usable format. The worst is when multiple cameras record at 15, 30, and 60fps and try to .watch up angles. Pain in the ass.
Working at a court house, I completely understand. Evidence gets submitted, and you can't play it without installing codec of the month. Some of those come from really sketchy developers, so we require conversion to a "vanilla" codec. I've even seen proprietary .WAV files which I didn't think was possible.
@@FloydBunsen I would think so. Legal/trial support services is a thing. Some firms have them on staff, but many outsource the job. There are probably some serious NDAs for handling sensitive stuff.
@@TechnoTinker Yeah. .WAV is a container format. I was having fun playing around with a pirated copy of the Fraunhofer MP3 codec for whatever predated DirectShow as a teenager back on Windows 95 and using that to put MP3-compressed audio into .WAV containers. I forget if Windows 3.1 did, but Windows 95 came with several different codecs for .WAV by default.
@@ssokolow I think Windows 3.1 had about 5 codecs for WAVs, and I just took it for granted that they were always one of the standard ones until that security footage came in. I was really hoping that I could just change the byte for the format, but it wasn't that simple. Wikipedia has some good info on the container layout.
Cool video. I'm more into digital IP cameras than analog stuff, but it's the same companies in both arenas. One thing you might find interesting: The "generic" DVR you were using from Annke is actually made by Hikvision. There are a very small number of camera manufacturers and lots of companies re-labeling those brands (They call them OEMs). Dahua and Hikvision are responsible for something like 80% of all security cameras on the market, but through many different names (for instance Lorex and Amcrest are two big names in the US are actually just Dahua rebranded cameras).
I'm not surprised, just didn't know who the oem was - usually it's not a brand that actually has any market presence of their own, but this market does have the feeling of being remarkably concentrated on a couple companies
So here's the thing - I've sworn these HD over analog CCTV systems off completely. Way too finicky over time. One: after a few years if the BNC connections are even REMOTELY exposed to the elements (I've had some in attics even do this) then you get ghosting and signal loss until you clean/reseat the connectors. Two: If you try to re-use older BNC cables you will likely get ghosting. When I replaced a SD system with one of these HD over analog systems about half the cables were just not up to the job and had to be replaced due to ghosting. Granted, they were prob cheap cables, but the freebies that came in the kit solved the problem. I'm only using POE based IP kits now. You can pick up a nice Lorex kit with EIGHT 4k cams, the DVR, and cabling for $800.
@@hicknopunk If you're going to go through that much effort, just flip to IP and be done with it. Most IP cameras come with a waterproof gasket to put on the end of the cable (8P8C connector) which couples to the camera's ethernet port. Analog just can't compete with IP.
I have a 20 year old BNC to VGA cable and it works just fine even after hundreds of unpluggings. BNC is a good connector, just wrap something around it for outside use and it should hold up aslong as any other cable.
One of the reasons you don't see things like this used for general video use... Copy protection. Can't let consumers use something they could possibly record!
"...switching to fiber optics, which costs a bundle." You bastard. A very interesting and niche technology, and I thoroughly enjoyed the increasingly massive bundles of cable.
This video was quite interesting! I maintain and do installation with a medium-sized CCTV system where I work (about 80 cameras) and some of our cameras are still AHD in places where it wasn't cost effective to run network cable - the reality of new CCTV installations in 2022 though is definitely IP cameras. Their picture quality is far better, the cable runs are much more convienient over Cat 5 or 6, and you get the benefit of having a hub-and-spoke style network topology with off-the-shelf network switches. Need a new camera in a place? Well the cable doesn't need to go to the DVR, just as far as the nearest network switch.
One thing we found is you absolutely need to use super high-quality cable for network cameras. Any CCA will crack over time in outdoor use. Another is water proofing. If any water gets into the connector it will fry the connector if not the entire camera. Since it's 48V. Damn near instantly. While a analog camera will simply degrade in picture over time. I also saw an analog system have it's wires hit by a semi truck and there was no damage to the wiring. The DVR just got ripped through the wall.
@@mgzukows not sure if you really need super high quality cable, i run my system on regular belden cat6 and it works just fine for years, i dont use those cable that can cost more than $300 per roll (1000ft) Water damage on connector can happen if installed incorrectly What i like about IPcam is the ease of use and installation, since i only install for myself, having to buy 2 separate roll of different cable and having to worry which ones which is annoying, ip cam solve the issue since i can just use 1 type of cable for network and cameras, not to mention my home setup is spread across two location so analog wont do the job
This channel and Technology Connections should do a collaboration! My two favorite video technology TH-camrs. Your videos make me very happy, I’m a professional video engineer and camera assistant born in ‘96 so I got to see the technology evolve, and consider myself lucky in that regard.
Fun fact: Triax based camera systems mostly operate with analog signals. Triax camera runs can be many 1000's of feet at venues like stadiums or other large events, and the bandwidth often isn't there in the cable at that range for uncompressed digital circuitry, and you can't add compression to broadcast camera signals because any latency isn't acceptable to maintain audio & video sync. Add in the needs for multiple signals in each direction, and the best solution is... analog RF. Most triax camera systems are literally a stack of very high quality analog modulators & demodulators in each end. Each camera chain is basically a tiny closed circuit 2-way cable TV system. And you can actually send all the video/audio/control/etc signals over normal biax coaxial cables with a simple adapter that just leaves out the 3rd conductor of triax that is used for (very high voltage!) power to the camera. True "digital triax" does exist, but it's rare and doesn't have the range of analog triax. ... Which is where the broadcast fiber optics come into play.
You have no idea how absolutely helpful this video has been to me! One of the things that is sold where I work are security/surveillance systems. Lots of people need much, much farther than what is offered with our kits. Now I know what these people need to go find. Thank you so much!
Holy crap I wish I'd had this information around 6 years ago, my last job I was head of IT for a manufacturing plant. My team and I spent over a month pulling all the old coax runs and replacing them with IP PoE cameras; unfortunately due to the nature of the manufacturing WiFi was completely out of the question. This would have saved me so much time (and money probably).
Ive been installing security cameras for a while, I was amazed by how similar all the various analog formats are (even used the oscilloscope to try and figure out the technical differences), and how they just refuse to be cross compatible. Cheap DVRs that support every format were quite the thing to see when they hit the market, and the cameras that can switch formats even moreso. Very handy in fixing up old systems for stingy clients who refuse to upgrade. That being said, we switched to IP PoE a long time ago 👍 PS. there is a way to make these cameras look infinitely worse to the point they barely function, and its done all the time to save money in larger installations: trying to run the analog signal over twisted pair using baluns. Those who know, know.
i was on the industry long tome ago... cctv is and will be caos.. every vendor wants to use his standard .. in analog or digital.. nowdays i search for onvif compatible and poe..
Re: Digital TV - I grew up in a super rural area where when the DTV transition began there was no cable service. Many families had used Big Ugly DIsh solutions, ourselves included. Of course Ka band stuff had come along by that point but it has two major problems: rain fade and capitalism. There were many times local channels from the closest cities (50 miles) just were not available due to contract disputes between Dish/Direct and local companies. Rain fade was way worse, living in deep mountain valleys rain fade was plain unavoidable and it meant that during significant weather events -- times when you might _especially_ want local tv availability to receive information on the situation and progress -- we were almost assured to lose service. Throughout my youth, we had two coax outlets in the living room, the feed from the LNB and the feed from our 20ft pole in the field with a directional antenna pointed towards the city. Even in awful, lightning weather conditions we could get a weak feed from our antenna of the two local stations we were able to receive. After the DTV transition we were never able to receive them again. Even with a Blonder Tongue broadband amplifier you could never get a stable, watchable signal. You might _get_ a signal reading on a TV scanning, but when you watch it you'll only get blocks and interrupted audio every 3 seconds. Eventually Xfinity built out cable infrastructure out here (through public funding of course) and the issue was largely solved for those who can afford cable, but it was frustrating largely that our communications reception was essentially shelved in order to compress the television spectrum down and resell blocks to private wireless carriers. The local HS also needs new microphones due to the 600Mhz block being auctioned of as well. Some things never change.
That auctioning of spectrum also happened to PAL bandwidth in Europe, but at least DVB-T and DAB transmissions reach almost everywhere, unlike your frustrating ATSC experience.
@@johndododoe1411 DAB coverage was awful compared to VHF Band II without significant infrastructure upgrades. DAB has already been shut down in Ireland, mobile broadband has better national coverage so it just seemed pointless. Meanwhile my FM radio from 1967 (with optional stereo decoder) still works fine
one thing I am surprised no one mentioned, I believe you can run these over a single twisted pair using a balun at each end, as coax is difficult to terminate and thicker to run. Would be interested to see the distance they run at. Great vid as always!
I was waiting for someone to mention the word "balun." When I was growing up, ham radio used baluns from 50 ohm radio feed to 300 to 600 ohm ladder line to the antenna. for security cams would it be 75 ohm composite to 100 ohm cat5 and back?
@@poofygoof standard video baluns go up to 600m because of cat5/6 impedance, while active baluns go much higher, ones that go up to 2400m (supposedly) but they need 12v DC. both types of cables can be used, but for long runs cat5 is preferred because coax is a pain in the rear end to terminate at the camera and doesnt really like bends.
@@poofygoof typical commercial video baluns would be termed a "current mode balun" by the hams I know, it doesn't actually match impedance, and you just eat the insertion loss. They're a common mode choke and that's all.
Here’s more food for thought. 480i component video is basically standard NTSC video split into 3 components right- luma/sync, and 2 color components. HD component video is basically just a sped up higher bandwidth version of 480i component. These analog composite component formats are most likely just HD component video converted to composite such as is done with standard definition composite and component video.
My mind is almost constantly empty, so I'm amazed every time you manage to come up with an interesting and engaging video idea. I have actually got a few in the works, and now that I have a proper camera, these ideas will move along a whole lot faster because of that. Lucky me.
I love how in the week I've been thinking a lot about how far you could push composite, you put this video out. I don't know how you're synced with my brain, but please continue.
The reduced refresh rate probably is helping a lot pushing the higher line count over long cable runs at a low bandwidth. Maybe some pre-emphasis and notching of mediumwave radio stations to avoid interference to the picture.
So I completed 3.5 years of training at a German company that specializes in safety systems. With various major customers who have used analog, digital and a mixture of both for their video surveillance systems. We mainly distributed Axis and dallmeier cameras. 1. If an analog system is already in place and you want to switch to digital, it's better to use an encoder. But these are not cheap. An example would be "AXIS P7304" for 1080p. You would continue to use the analogue cameras, which would be recognized as digital cameras because of the encoder. (Also, I've had the experience that the analogue system lasts longer than the digital one. At least in the professionell area.) 2. The advantage of RJ45 (ip) is that no additional power cable / control for PTZ control or audio to the camera itself needs to be drawn since it can be supplied with power via POE (POE+). it saves costs by eliminating the power line and eliminates one possible problem source per camera. In addition, cross-location video distribution is possible via vpn . 3. If the range of CAT6 at 100 m is not sufficient, we used fiber optics. This requires a converter which requires an additional power supply. However, this has the advantages of an electrical separation, which customers appreciate when ther camera is mountet oudside and the recorders are in their server rooms dirictly cnectet to the ouside. (Lightning strike) 4. The resolution of a camera is rather uninteresting. What is more important is the pixels per meter. Means a 4k camera that is completely zoomed out and should recognize someone who is about 200 meters away is completely useless. whereas a properly oriented/placed 720p camera would do a better job. (There are guidelines that specify how many pixels per meter are needed for different degrees of identification.) Besides that, it depends on the bandwidth. Both for storage and transmission frame rate. t
I was actually really surprized, when I realized, how little analog signal need to function. For PAL signal you only need around 50kHz of bandwidth to grab on that sync and see some blurry shapes. I was able to record video signal over soundcard at 96kHz sample rate and got flying ball instead of DVD logo, but it was really impressive for me to see, that it has sync and i can see anything at all
I've heard of people pulling off analogue TV reception with RTLSDR recievers (which can do a 2.8MHz sampling rate) and getting recognisable (if blurry and monochrome) pictures out of it, but I never would have expected you could go as low as 96kHz and still have it work, however badly.
@@VPWedding 5px is enough to roughly see a bouncing ball. And as the sample rate isn't divisible by the scan rate the sampling phase will change each line, probably increasing the effective resolution.
30 year instrumentation and mechanical journeyman here,,, and I have been a property owner since I was 23. I also am a gearhead/carguy. As such. I am self taught on cctv systems that range back to the Zmodo junk that was on ebay in the late nineties and showed grass and trees to be PURPLE!!. I didn't care about the colors because I was just trying to catch trespassing thieves. I just subbed because you are the first person I have discovered who has addressed this subject matter in a cohesive manner. THANK YOU SO MUCH!!!! I am thrilled to find your channel!
This might be a consumer variation of the 960H trick you mention. Commodore introduced a Super-Hires NTSC (and a Super Hires PAL). mode with their Amiga 3000 in 1990. It gave you 1440x486 NTSC 35ns display mode. With the enhanced chipset (ECS) it was limited to 4 colour mode. When Commodore released the Amiga 1200 & Amiga 4000 in 1992 with a new chipset (AGA - Advanced Graphics Architecture), it was capable of using 8bit planes and a 24bit colour palette in all resolution modes including Super Hires NTSC (and Super Hires PAL) mode. HAM8 could also be displayed in the Super Hires modes, simulating an 18bit colour display with a 24bit colour palette.
Historically, Ethernet ran over that RG-58 coax, known as 10-Base-2 or "Cheapernet" because it was cheaper than the heavy RG-8-like coax used for the original 10-Base-5 Ethernet. All of these were 10Mbit/s with CSMA/CD bandwidth management. If those Ethernet converters provide more than 10Mbps over RG-58, they probably use a different data encoding than the original crappy 10-Base-2 signaling.
This would be 10Mbps max, as its a shared bus/cable (so no separate send and receive lines) and would need to be able to fix the Video stream and any commands/diagnostic data. Would be possible, but probably only at SD bitrates, in which case, analog signals would be fine.
Actually this was useful...I've an aging pal galax 960h system here in the UK that's been in service for well over 10 years now and want to "upgrade" to a higher resolution system....thanks dude.
I belong to SMPTE. The ITU-R Rec-601 is 720x486@270mb/s. Fun fact it was called CCIR601R before that, and was a parallel (NOT serial NRTZ) digital signal over a 25 conductor DB25 cable and connector! Look it up! the cable was super low capacitance (something like
Yep. I have a Sony D-2 deck in my basement with a composite digital parallel connection. Super fun thing was learning that even though you can use a parallel to serial converter, it's still composite. All normal serial digital is D1 component. Had to get a format converter to change it from D2 parallel to serial then to SDI (D1 component).
Dude! When i worked in live productions, small home security installing, and managed an electronic stores I was always taught HD could only go like 50 to 100ft before the signsl would break up, analog or digital (yes to those asking digital breaks up too by having digital snow and crazy picture, its not as simple as its there or its not like most people say.) This is so awesome! Addendum: ive never seen a tech youtuber tell the truth about a digital signal till you did. You showed what it does! No one ever believes me because everyone is like "see this article says its on or off and you don't need any of those special cables you can youse a coat hanger"
Here in Romania one of the major ISPs had internet service through Coax using cheap Ethernet-over-Coax equipment. I think the whole line maxed out at 150 Mbits and at least 10 people would be connected to it, meaning speeds were not that good. But now we got amazing fiber which is much more reliable.
@@RaduTek It’s really common for almost most places in the US to have cable internet as well. Lots of places can’t even get that and have to use phone lines
Ethernet cables were often coax in the past anyway = 10Base2, with 'token ring' plugs(the same plug as many security cameras use), so I'd imagine converters have been around a long time, although speeds were lower then.
One of the cheapest option for these coax adapters is "DECA"... the in-home adapters, meant to share coax with cable TV, overlap with satellite frequencies. DECA adapters are meant in turn to share coax with satellite systems, and will scramble/be scrambled by cable TV. If you're using them on plain coax, the inability to mix with cable TV is no longer a downside.
Hi. Thank you for the interesting and informative video! I had been under the impression that "960H" meant "quarter 1080p" or 960x540p. It looked to me like they were using confusing terminology to trick people into thinking that 960H was higher resolution than 720p, when in fact it was significantly worse. I _do_ know what the "486 lines" business is about. The standard designed in the 1940s had 525 lines. 486 if these had actual picture information, while the rest were black, so as to give the electron beam time to get back to the top of the page. When JPEG was invented and applied to video, it was observed that JPEG required interlaced video to have a line/pixel count divisible by 16. By pure luck, PAL's 576 on-screen scan lines matched this, but NTSC's 486 lines did not. Rather then waste data recording an extra 10 blank lines, they decided to remove 3 from the top and 3 from the bottom, thus creating digital-NTSC's 480 lines of resolution. These lines were in the "overscan" area and would not be visible on most sets anyway. This also explains why NTSC has this strange even-field-first scanning pattern for interlace. What we are calling line one today was actually line four when 486 of the lines had actual visual information.
I actually used a Hikvision IP camera as a webcam But it was 2020 and I fit CCTV so had some spare ones To be honest I have never used the analogue HD systems I went straight to IP once it became cheap enough I have used the SD analogue encoders though (like that Axis P7214 on your desk at the end) they work well when upgrading old systems but want to keep some old coax cameras working Hikvision did dabble in digital HD SDI cameras though. I bought one a while ago and the image is actually nothing like a security camera. its a semi broadcast quality 1080p image as its not doing much processing to the image for even-exposure
The only commercial systems I've worked on were all IP cameras with strategically placed switches to keep the wires short enough. Never occurred to me before that analog would've been used prior. Neat.
There's another major advantage of using analog video: You effectively have zero latency (provided there are only analog components in the chain). That property is sometimes 'exploited' in things like theaters, recording studios and orchestras where the conductor may be in a different place than the musicians and the performers want to see the conductor without any lag.
Thanks! Ive wondered how they did this since i first installed one of these HD surveillance systems several years ago. Turns out they just turned up the bandwidth limiit on plain old NTSC to get more horizontal lines. And more resolution on each line. Cool! And nothing anyone could put a patent on. It remind me of the first NHK hd cameras and recorders in the 80. Those were analog RGB, 10 Mhz for each color channel, 30 MHZ total. Standard def was less than 6 MHZ. That caused a lot of skepticism about hd broadcasting in the beginning as we would have had to open a whole bunch more channels at the same time cell services were looking to expand.
I got a good laugh out of that, especially with the perspective being about 90% correct so those who wanted to see it was a bit wonky, would, and those who didn't, wouldn't.
Super fascinating. I'm a bit of a HD+ analog nerd and I had never heard of this. I've been doing a bunch of work with 1080p composite. I've also been sketching out extending composite to 4K. The numbers work, but it's really pushing bandwidth constraints, and that's over 3 cables. Even with the chroma subsampling that you get in composite vs. component, doing 2k or 4k over "NTSC" is batshit in terms of the bandwidth you're trying to cram down a single long wire. In fairness, your HDMI->HD-TVI->HDMI test was using a very difficult test pattern. In the analog domain all of the hard edges in the grid lines of a test pattern will highlight bandwidth constraints from parasitic capacitance, or just poor PCB layout. A few years ago I did a video comparing a cheap Component to HDMI adapter vs. one from Blackmagic. The difference in engineering is staggering. So much thought needs to go into the analog domain to avoid the smearing issues that you saw.
Good video! I had no idea that this kind of HD analog video was a thing, I figured at the beginning that it was going to be some kind of rf signal since that can go pretty far in the right kind of coax, but I didn't expect it to be roided up NTSC 😆 As part of my job, I occasionally install security cameras, and as you guessed everything commercial is IP-based, kinda boring. However, usually to run long distances (like between budings, or even multiple campuses, assuming they don't already have cable/fiber between sites) we use point-to-point wireless IP Bridges. You can get a consumer kit for under $200 that can pretty easily handle two or three 2K video streams at a thousand feet, and if you get the "spare no expense" commercial stuff, you can span literal miles at gigabit speeds or higher! Setups like these theoretically have a potential to lose data more often, but a properly installed commercial bridge can go for years without interruption or downtime, effectively no less robust than running fiber or cable.
Hey, I'm a security camera enthusiast! During most of the beginning of the video I kept yelling "IP camera" at my phone, and I'm glad you brought them up. They really are the answer to this problem. You're right, the cost can be expensive, but there are ways around that, I work for a company that solves this whole problem for our customers. But great video overall. By the way, Hikvision is pronounced hike-vision, and Dahua is pronounced dawua, you don't pronounce the "h".
Jesus Christ finally someone who's got it right on digital TV, thank you Gravis. I've really tried to make a point to folks about this social issue aspect of it, and how it made watching TV markedly worse, overwhelmingly for the poor, but you've put it so succinctly in one sentence.
I think a lot of the reason people push back on this is just because an awful lot of people *don't see it.* I've talked to folks who have had a perfectly fine time with ATSC, and given that TVs are generally, you know, fairly stationary, if it works once, it'll keep working.
@@CathodeRayDude yeah that's fair, a lot of people never had to deal with awful aftermarket shitboxes, which I think is still the dominant experience in poor countries where people couldn't prioritise buying a new TV. Those are dying off now, but at least here everyone still clearly remembers how responsive and reliable even the worst analogue tv was compared to the landfill garbage used for DVB-T. At least we still have Teletext, for what that's worth lmao
The thing is, coax carries the data from the satellite dish to the box, or from the aerial to the box, but HDMI is needed from the box to the TV. We know coax can carry all the data required for HD signal over a long distance, because it does that in every house.
Both HD satellite programming and broadcast HD use digital modulation schemes, while these security camera standards are using baseband video... going from "a solution exists" to "buy this product" is engineering, and I think that's what this video is appreciating.
RG-59 coax is typically used for CCTV systems (baseband video, not RF), it's not good enough for UHF or satellite TV at any length (ok for a fly lead but that's it). Coax good enough to connect your satellite dish is a lot more expensive.
I've found that you can even run HD-TVI signals through a single twisted pair of wires. I've got 4 cameras on my parents' barn all running through a single Cat-5e cable that we trenched underground nearly 20 years ago (with the intent of eventually using it for data or telephone, but hadn't utilized until I installed the cameras in 2017). The 4 signals travel through more than 400 feet of standard UTP Cat-5e cable, yet it's surprisingly clear (despite my ham-fisted install job using old screw-type terminal blocks). I'd always wondered what the technology behind it was and your video really cleared that up for me. I greatly appreciate your work in creating this (and all of your) interesting video(s).
I actually own a business and do cameras/networking/production for a living. I typically use IP cams. So far, my longest run with an IP cam was 508ft through a single CAT6. Camera has worked flawlessly at 4k 15FPS. Also I've ran component video over 175ft through RG6 coax terminating with RCA connectors. Works great but it is rather bulky with 5 runs going to every device
Component video is amazingly tolerant... short runs to a newer TV that uses a TRRS adapter can be extended with a 4-pole headset extension! Then again, I did use a gold-plated headphone cable, that's potent homeopathy. 🤣
I work in enterprise I.T. and and have lots of experience with CCTV. I gotta say, man. I love your videos. You're very well spoken. Your format is never short-form and you're very detail oriented. You deserve all the subscribers and views in the world! Please keep making your content. I'm giddy when I see a new Cathode Ray Dude upload. Seriously - Love your content. Thank you for uploading!!!!
AHD/TVI was used in a video transmission system for drones then called Byte Frost by Fat Shark so that's where I first read about it. In subsequent iterations of the hardware they threw away AHD and went with MIPI-CSI with a proprietary handshake protocol. Oh and also all analog cameras for FPV drones such as Runcam/Foxeer/Caddx are basically repurposed security camera sensors with slightly better lenses. FPV wouldn't be that dirt cheap if not for the security camera stuff. Yeah, our hobby was pretty much entirely analog SD well until some three years ago when DJI released their bonkers digital HD transmission system, but that's for another story.
I feel the need to correct things: digital signals can travel much further and longer than analog signals fom the pure signal transmission side. It's the implementation on the sender and receiver that sucks. There are implementations that lower the bitrate and get a perfectly good signal (e.g. in modern RC rx/tx) with whole lot of algorithms and ideas. That is just not implemented in TV stations, since they are designed to cover a given radius.
It's really weird that the artifacts you get with composite like the dot crawl and crosstalk aren't that much of a deal breaker at higher resolutions. The moment you switched from the usual composite 480i, it's perfectly acceptable.
Same reason dot crawl wasn't really a problem with a portable 5 inch CRT: you can't see the individual dots anymore they're too small. More dots or less screen, same result.
Love this! I was very impressed with the quality of the footage when we installed our security system, and was interested in just how it was doing this! Definitely agree that these things work fantastic for the very low cost.
From the coax cables I always assumed HD surveillance systems were using something similar to ATSC QAM or DVB-C (basically a small cable TV system) to get around the distance problems.
I am an electrician with extensive security and surveillance experience. And to other electricians, I am a nerd. As such, I came for the tech and was captivated by the history behind the tech. I do remember 960H, but it was very fleeting before the digital takeover. I still install NTSC coax cameras for their resilience and when necessary, I convert the coax to EOC (ethernet over coax) and then use a switch and IP cameras. But analog, as you said, it is far more robust and for the price is still a very good option. Hybrid systems exist so you can retain your older but still useful cameras and update with 4K ones all on one system.
Not only did I NOT seek out a half hour of imaging tech info, or to give ti my best focus this week, but I had stuffs to DO man, this held me hostage. Thanks for the excellent presentation.
Two things come to mind having watched this. The first is that if they did this over S-Video, most of the degradation problems would go away, but the technology wouldn't have to change drastically (S-Video can be converted back to CVBS at the destination passively, though using transistors looks better). The second is that cramming more horizontal resolution in the signal was something that many games supported on the PS2, Dreamcast, and GameCube. I think there were a couple of PS1 and N64 games that did it as well. Usually you'd have to hold a button while the game booted, though sometimes the code was there but inaccessible without a GameShark. Often, these were artificially limited to component/RGB cables because 960x480i over CVBS wouldn't be supported by most TVs, even those that supported widescreen, but that's not always the case. The PS2 can be configured to try to shit out 1080i over composite if you wanted (though this wouldn't work without a processor that supported custom timings). We got so close to an analog HD future, but it just didn't materialize.
Changing to s-video would require using different cables, which would defeat the purpose in many cases. From memory the oldest game consoles did the reverse with horizontal resolution, outputting less to make processing easier.
Bandwidth limitation. It had to fit within a 6Mhz broadcast channel signal allotment. If you tried to go higher there’d be interference with adjacent channels. DTV made it possible to use digital compression to fit HD channels in the original 1940s channel width assigments. But with a cable you don’t have that bandwidth limitaton.
@@StevenBradford Also of note, most PAL countries had wider channels. 7MHz in Australia, 8MHz for most of Europe and China. 6MHz PAL channels were quite unusual and only used in a handful of countries from South America.
This video is not only very interesting, very well made, with excellent research (as usual in this channel), but super useful. I was literally wanting to know more about this technology and this was a very didactic approach. Thanks very much and keep the awesome work!
The digital tv thing being a poor tax is 100 percent. And when we moved to internet tv all the companies have been slowly jacking up the prices to just make us go to cable. Hulu live tv forced us into the disney plus bundle this month. And here in Rhode Island we get Fox 25 from Boston more often than we can get Fox 64 out of Providence. They turned down the power on all our transmitters to make the antenna useless. Those cheapo usb dongle capture cards make great webcam and old console cards. They do 720p 60 no problem.
Boston is far larger and richer and more important than Providence, so of course their antenna tower will have a stronger signal. If what you say is true about reduced power on RI transmitters, complain to the FCC or your Democratic representative.
It's hard to find good ones though. We put those in a few client places. Since essentially the max for an HDMI is 75ft with a built in amp. They fail way to often to be used in commercial applications. Unless you go real high end.
True HDMI over ethernet is distinguished from HDMI over twisted pair extenders... ethernet converter systems often have extra bells and whistles, like passing IR remote signals. These units tend to cost around $100/pair, and in fact are generally compressed MJPEG or H264 in RTP/UDP/IP on ethernet. They can be set up as a relatively low cost video switching system using a managed ethernet network switch, placing as many receivers as you want in the same VLAN as the transmitter. Doing this with the cheaper, simpler to find HDMI to twisted pair converters won't work, and may damage the devices if you try.
Wow, I was literally looking into this same kind of thing about 6 months ago. Didn't chase it to the same extent you did, but ultimately came to similar conclusions about usefulness versus other options for my application. I wish I had seen this video first, though, because it would have saved me a lot of time researching.
AHD/TVI/CVI are pretty much the same but have different colour subcarrier frequiencies, and also the subcarrier is above the luma i think, rather than overlapping like PAL/NTSC
Im cofused as to how that would work. Do you mean the chroma signal is in a different section of the signal from luma? In which case why would you need subcarrier? As pointed out by CRD in the video, the signal looks like NTSC on a scope.
@@willyarma_uk As I understand it the chroma is “overlapping” the luminance. The subcarrier burst is in the horizontal blanking but doesn’t have the color in it. I think i was just misunderstanding what you wrote.
@@StevenBradford Ahh right, no the colour busrt in the blanking period is just for synchronization. The chroma is quadrature amplitude modulated and then summed in with the luma. What I meant was I think the the frequency of the subcarrier is quite high so it dosent overlap the frequencies of the luma as much.
I appreciate the many times in this and other videos where you fade in footnotes that aren't important so the script glosses over them, and I'm not one of the people who are going to pause to read it all, but it does communicate the degree to which you're simplifying a complex subject so I can intuit the degree to which I'm not leaving this video with a deep understanding of (some of) these subjects
CCTV Installer here (europe). We install 4k and 8k IP cameras daily. FullHD or 2k is basicaly obsolete in this buissnes. It's actually pretty scary beacuse most of Hikvision, BCS and Dahua (biggest players in the industry) cameras have face and number plate recognition chips onboard, only the cheapest ones don't and we rarely see that clinets want them. Pretty much every hotel, shop or office with modern CCTV system is running them and they see everything in freaking 8k (though 4k has more quality playback for some reason but i quess it's sensor size problem).
But wait! There's more: Security of those cameras is bullshit. If you can see the camera (and sticker on it with serial #) you can literally ask HikVision or BCS (dunno how's the situation with dahua but i quess its the same) for one time master password to reset the camera (yes, SN needed for resetting the camera is literally on the sticker on housing :) ). You have to be registered as installer and shit but i bet there are registered people who will send that email for you for $10. If you have access to the LAN/WLAN you can find out cameras' IP adresses and reset them, do whatever you want with them and set the old IP adress so the recorder is still recording like normal. Recorder is dumb, it doesnt know what is going on with camera, the camera just sends video over IP and thats it. And there is that thing that even when someone is watching playback on screen they propably wouldn't notice the camera went offline if there is little movement in frame, because the playback just hangs on last frame that went through. So you can cut the UTP, connect camera to switch, splitter or something and propably nobody would notice. Also, those cameras freeze on day to day basis so if the playback stops, security guy propably would not care. Even those hardcore mall-cops don't care, its bad. Analog cctv is more secure 👌
Wow. So is this long distance too? So if iphone 13 pro has a 12MP camera, which means a 8k ip camera in theory could easily transmit it long distance? I wonder what components would one need to build to have a hardware/software based solution that does the conversion digital -> analog -> digital and carry 12mp (or 3x 12mp cameras)? What is the example part# for the 8k camera? And one more question. If someone let say had a "Sony A7R IV" with 68MP camera, could this technology in theory be able to sustain the signal over cable, or you would hit some max carry frequency?
@@MrInterestFull this is not so much about how many megapixels does sensor have as about bandwith and bitrate of your stream. You can have 100MP sensor and only make 1000kbps video out of it.
I actually do this for a living lol. I regularily build hikvision cams, though im thankful most of it is ip. What you mentioned of replacing old cables is costly, isnt that much a deal in reality, in fact, if a company already wants to put in surveilance, and have a large area to cover, they got the money. Stil, very interesting video!
10:25 There were two (at least partially) analog HD video formats : HD-MAC and Hi-Vision/MUSE : en.wikipedia.org/wiki/HD-MAC en.wikipedia.org/wiki/Multiple_sub-Nyquist_sampling_encoding
@@debranchelowtone Most TV sets weren't good enough to show an improved picture in 819 lines than in 625 lines. There also was a 1025 line project at the time the 819 line system had been adopted.
@@chucku00 Sure it was far from perfect, cameras had their limitations too. The experimentations started in 1941 with more than 1000 lines. By 1970 until the end in 1985 almost everything was shot in 625 lines and optically converted to 819 line. So it didn't look good at all during the last years. HD-mac appeared later. Very interesting one too.
@@debranchelowtone Je bossais à la FNAC quand les expérimentations HD-Mac ont eu lieu en 1992 pour les JO, avec le fameux téléviseur Thomson Space System. J'ai connu le 819 lignes jusqu'en 1983. Et franchement, mis à part la meilleure réception en VHF qu'en UHF là ou je vivais, je ne voyais pas trop la différence entre 625 et 819 lignes.
Back in 2008 I had a tour of the video surveillance system in a large casino. All of the cameras ran over coax, for a specific reason you didn't mention - no digital lag. The timing of the video signals, and the matching between them and all of the other systems recording exactly what happens when, is critical to how they are used in a casino environment - to identify and catch cheaters in the act. As I recall, all of these video signals were brought in over coax and then split between the live control room (where they had the pan / tilt / zoom controls), and the recording facility which in the day had dozens of racks, each of which had dozens of RUs of USB video capture devices - each of which took one analog signal in, and converted it over USB into a device that would record the output and then pass it through to the digital storage that was again all separated from those capture devices. It was fascinating stuff for me at the time, and a complete eye-opener as to the different priorities that dictate how video surveillance works in this type of high-stakes environment. Thanks for your insights - and I hope that one day you might find one of these decades-old devices being sent out to pasture, and you can rediscover this weird transient technology from the day!
Hah, analog wins again! Digital over any amount of distance always seems to be worse than analog in terms of robustness, at least in my experience. The worst offender I've seen is digital "HD Radio". Trying to keep a digital AM/FM signal while driving is rough. So rough that being able to seamlessly switch between digital and analog as conditions worsen is a big part of the standard. Really fascinating video, I really enjoyed it man! Thanks!
With wired connections, digital can go pretty far and still be robust. Wireless transmissions, such as TV, radio, and Wi-Fi, on the other hand... Analog does so much better in that front.
Great video, bet this is gonna be one of those channels that blows up. A/V and other cable standards are fun to me I feel like if I were to set up a security camera system I'd just use IP, just because I have so much ethernet cable lying around, and repeaters, etc etc are a dime a dozen
2:24 Waaaait a sec. What's going on with that logo there? It shows up on the wall in the video and on the wall on the monitor in the video but not on the wall in the monitor in the monitor.
Thank you so much for this enlightening video. The challenge of pushing video over long distance cable brings back memories of the days of broadband internet over POTs line - ISDN / ADSL and other other technologies predating cable and fiber. How much bandwidth can you get out a twisted copper pair to your telco - a lucky few get 1 megabit or more while most contend with far less. Thank goodness we went pass that in pretty short time.
This explains why my crappy Swann home security system uses what appears to be coax, and why one of the cameras always seemed to have faint coloured bars scrolling down it. Never really thought much about this. Great vid!
Im reminded of a conversation with a classmate who was researching computer vision systems for traffic intersections, who mentioned that there was competition between analog and digital TV signals. I remember scoffing at that as obviously outdated information (partly because I forgot an entire era of A/V equipment and imagined like a vidicon tube...). I would be willing to bet that's what this technology gets used for: sending HD video over a wire from a traffic intersection to a computer to run a bunch of complex computer vision math, and its all just NTSC!
The closest we have today is VGA. Which is surprisingly high quality for a analog video format. With WXUXGA you can get 7680x4800 and honestly if you put it side-by-side with HDMI on a normal lenght cable you wont see a difference hahahaha. Most people like to say that VGA has loss of quality but I never saw someone actually prove it. Because if there is, its pretty minimal, and most of the time can be blamed on the converter. The major problem is that VGA can suffer interference by being analog. As said, on analog the interference is just plain added to the picture, while HDMI, or the better DisplayPort will black on interference but its really hard to have enough interference to black a 15ft HDMI/DP signal, while its not that hard to have some imperfection on 15ft of VGA. Also, theres the major problem that the driver on a moderna LCD is digital, so you're most of the time converting digital to analog to digital and back to analog to drive the pixels. Manufactures dont want to add the cost... Thats why today less and less TVs come with composite (they exist, I swear).
👍👍, I have a tower and HP VS19E (VGA, 1280x1024@75Hz) monitor and a couple old laptops with 1920x1080@60Hz eDP/LVDS displays and when I put them side by side I can't tell the difference they all look really good to me but I also have a high quality VGA cable and my current graphics card is from Gigabyte (a Radeon HD 7750 2GB)
It’s not surprising at all that coax can do analog HD: coax handily carried dozens and dozens of analog SD channels simultaneously. So the analog bandwidth is there. The HD security standards are simply allocating all of the available bandwidth to a single signal, rather than dozens of signals, and thus that single signal can itself have a very large bandwidth. Digital absolutely can be designed to degrade gracefully. On the one hand, we use error correction encodings to add redundancy, but moreover, the reason digital signals tend to fail badly is that they’re compressed (which makes them very un resilient) and often encrypted (which will often simply break the link entirely when errors occur). The audio CD is a great example of very resilient digital encoding. The analog waveform coming off the laser pickup (typically called the RF signal because of its frequency) shows how much variation can be tolerated before the digital circuitry can’t make it out any more. But then the encoding (EFM and CIRC) enable both bit errors and block errors to be corrected (which is why minor radial scratches don’t cause any problems). And then even if a particular frame of audio cannot be recovered, it can either be dropped (causing a minor audible glitch) or interpolated (causing a bit less of a glitch). But this works because a CD is the exact opposite of compressed: the raw audio data is actually inflated with an extra 75% of redundancy data.
The irony is that fiber optic cable is actually cheaper to manufacture than coax. They just charge through the nose for it because it’s marketed as higher-tech.
A wild TayZonday appeared! Internet legend!
The main reason is that its much harder to terminate for networking than coax - if its a custom run and not a prefab you're going to pay to have it cut and polished and that racks the price up significantly.
I just read this comment and was like, huh, that's pretty insightful. Did not expect mr Zonday himself to be the one raining this wisdom down on me.
No, they charge a lot because terminating fiber cable, and the connectors, are more expensive than coax.
chocolate rain
Love how you greenscreened the T-mobile logo into every of these video feeds. You didn't HAVE to do that, but I love your attention to detail :)
I had to rewatch this section several times in amazement to the editing skills. Really loved this, had my brain going crazy
@@kol101101 But he didn't bother with the tertiary mirrors.
I couldn't believe it was edited. I thought SOMEHOW the signals were directly interfered with.
this. The fact he took the time to do that, just... Bravo, man.
What time is this part?
Security camera enthusiast here (my "home" CCTV system is 80+ cameras strong and my collection is 500+ cameras and 120+ bits of control equipment)
TVI and CVI also are able to pass audio and control signals both ways for configuration of the camera and PTZ control from thr DVR (provided it supports it)
Most of those AHD DVR machines are basically a RISC V / ARM SoC with a hardware accelerated video processing unit. Some are on the same chip. Thr good ones have a dedicated video chip that communicates with the microprocessor via PCI-E.
I run all of my CVI cameras over twisted pair cable and provided there is a good converter on the receiving end, the video is surprisingly sharp. TVI cameras I run over coaxes (there slight differences and TVI is slightly more sensitive but the overall picture is a tad bit nicer in my opinion)
After buying a lot of TVI cameras I found the best one of them all is probably the HiWatch (Hikvision outside Europe) DS-T226 so it might be worth a look at that to see the really high end TVI there is.
I knew there had to be ONE out there! Haha, thanks for the info!
@@CathodeRayDude Always at least one out there
Hey, at least your home is nice and secured !
@@CathodeRayDude I was wondering when you were going to go down the surveillance rabbit hole. Lots of boutique solutions for boutique circumstances in the industry. The HD-TVI cameras more or less exist because of all the old coax that's still in these buildings from prior runs. A new system would just be POE because you can go even farther than the numbers you quoted for POE in your video. You use an Ethernet to Fibre media converters to go farther. A media converter will get you 600 additional yards for less than $100.
It looks like this:
Camera -> POE Injector -> Media Converter -> Network (which may or may not have a corresponding converter back on the other side depending on your hardware).
Then there's the wireless meshnet stuff some dudes are doing on their ranches using small radio towers to network wireless trail cameras. There's a lot of really cool tech in use at modern ranches.
"Hello Sir/Mam, we got a call about a B&E at your premises, you wouldn't happen to have a security camera?"
"Well..."
To the point about graceful signal degradation in digital: This actually does exist, and the only company that I know who does it got their start in AHD security cameras. Divimath, who make HDZero FPV drone racing transceivers, have their signal processors accept basically any data and display it uncompressed, as-is, so while the picture is digital (some kind of JPEG-like DCT compression) it fuzzes and fades very similarly to analog.
Okay that's VERY exciting, I would love to see this in action!
Ah, neat! It does seem like the goal of a standard video codec is balancing compression with quality, but ignoring robustness for the most part. Data between key frames is so dependent on being intact (since they use complicated methods to store differences between frames rather than whole images) that missing a small part can destroy the whole image between the key frames. So with data storage and transmission being less of an issue, it makes sense for there to be a market for more robust codecs in certain situations. Too bad it's too late for DTV.
Oh neat! That completely matches up with my experience with FPV drones, but I never knew the reason the signal/picture acted like that :)
@@nooneinpart That's what DTV should do/look like if being used in a sub par situation in a sane world.
And now that you mention that. Even just transmitting analog HD over a wider pipe as a downlink would probably be godsend for high performance drones.
Amazing video! I’ve always wondered about those HD camera systems that seemed to use coax. Now I know!
Woah! The best crossover
............bad news, it says coax? but in reality, it is 3 non shielded wires, red yellow and ground
if you dont deal with security cameras you would never encounter this crappy cable that claims to be coax
they also abuse "poe" cables similar, it isnt an actual ethernet cable, it is the same cheap 3 wire system the coax uses!!
I always thought it was HDSDI (and I'm pretty sure some of the higher end ones are). HDSDI is the same digital data as HDMI, but combined into one serial stream, rather than 4 parallel streams, and with appropriate cable drivers to go long distances over RG-6 type cable (and even further if you use better speced cable). You can get converters from HDMI to HDSDI and HDSDI back to HDMI for not too much money on amazon. And that's the retail price - if you're buying the chipsets in bulk for manufacturing cameras, they're basically dirt cheap.
@@gorak9000 Before HD-SDI you had SDI. I won't be too surprised if that standard accepted signals way beyond the originally intended limits as technology was progressing but a new standard wasn't fully standardised or even accepted by the industry yet.
The big difference with HD-SDI is that it usually bypasses all image-processing circuitry in a videocamera and outputs raw sensor-data. HDMI sometimes does that too, but considering it's more a consumer-standard, not every camera supports the same data-throughput on HDMI as it does on HD-SDI.
Personally, I prefer HD-SDI, as it features a locking connector (BNC), angled connectors are easily obtained, can have a nice thin cable if you only need to go from the camera to an extra monitor, where HDMI-connectors are always bulky, don't lock, are hard to find in angled-positions (and if you do, they always 'angle' the wrong way) and thin cables are very expensive.
All the advantages of HD-SDI is also why I make those cables myself. 50 Euro or more for a short cable is just ridiculous. Now if only some manufacturers of monitors would use more standard connectors (ugh ugh... Blackmagic...)
@@weeardguy There's no way SDI accepted signals beyond the SDI spec. SDI was an older standard for uncompressed SD digital video. It ran at the same clock rate as ASI (mpeg transport stream over serial interface). Both of them have a fixed data rate of 270Mbps. ASI uses 188 byte packets, and if the data rate of the transport stream is less than 270Mbps, the unused 188 byte packets spots are filled with "null stuffing packets", but the physical wire is always running at 270Mbps. Similarly for SDI, uncompressed SD video, you basically need the whole 270Mbps to send the video signal (and associated uncompressed digital audio - there's a fixed number of audio channels you can send). Because the physical clock rate on the cable is fixed, there's really no room to "accept signals way beyond the originally intended limits". HD-SDI is basically the same thing, but with a higher clock rate (1.485Gbps) meant to carry uncompressed HD video. There is no ASI-equivalent at 1.485Gbps or any of the higher speeds - ASI still tops out at 270Mbps. There's also 3G-HD-SDI that runs at 2.97Gbps, 6G-HD-SDI that runs at 6Gbps, 12G-HD-SDI that runs at 12Gbps and 24G-HD-SDI that runs at 24Gbps for carrying higher and higher resolutions of 3D, 4K, 4K 3D, 4K HDR, 8K HDR, and beyond. If they wanted to invent a new standard for HD security cameras, I'm not sure why they didn't take ASI and slow it down - put the video encoder in the camera, then you have somewhere between 5-15Mbps of data you need to send back (depending on desired bitrate and video encoding mpg4 vs h.264 vs h.265). They could've taken the 270Mbps of SDI, slowed the clock way down, say by a factor of 10x to 27Mbps, and you'd have more than enough bandwidth to send back 1 encoded HD stream per camera. There's no reason to be sending back uncompressed video down the cable, that's just dumb. I'll bet with a clock speed reduced ASI running at 27Mbps, you could probably send the data back over 2 coat hangers next to each other (or the worst coax imaginable) and it would work just fine. For cost, I see no difference having the video encoder at the camera side, or at the DVR side - seems that it would be the same either way, but at the camera side means you have a lot less data to transmit, so much easier to do over crap cable.
Wow, this was surprisingly interesting. I suppose this explains why the HD video cameras at my work seemingly get analog video artifacts/static rather than digital ones.
That's interesting. No compression, either, I think. So your work cameras would probably represent a snowstorm quite well, where my home cameras have compression artifacts with so much moving detail.
How did you post 12 hours ago on a 1 hour old video?..
@@supersophisticated9943 Patreon link
@@R.Daneel Still gets digitized when it gets saved to the DVR.
@@supersophisticated9943 Different time zones
2:20 the dedication in putting the T-MOBILE logo in every single one of your feeds on the monitor is admirable. You didn't do it recursively, so not quite the insane level of dedication one *could* apply to this, but nonetheless, I appreciate the base level of thoroughness!
you just made me realize all my security cameras (that were not installed by me) are not shit, they are just not configured to actually output hd . . .
oh man did you just go in and flip the switch and now they're all HD? hahaha
@@CathodeRayDude no joke . . .
@@enryfrafranci free upgrade! Awesome.
I found out through an internship that the world of analog CCTV is, was, and always will be surprisingly complex. To think that they had multiplexed pan/tilt/zoom features for dozens of cameras over a single coax cable in the 1980's is incredible.
In the '90s I remember hearing about plans for a stopgap system for consumer use that would stitch digital video onto the sides of a 4:3 analog TV signal to create a widescreen image while remaining backwards compatible with existing TVs. That didn't go anywhere, I guess due to the FCC realizing how lucrative it would be to abandon analog so they could cram multiple digital TV signals into a single transmitter and then sell off the upper UHF channels to mobile phone carriers.
Put "wikipedia palplus" into a decent web search engine. It was briefly used in several European countries. My Sony DHR-1000UK DV cassette deck has the PALplus decoder built in.
And where would the frequencies for that extra bandwidth to carry digital sides come from? Also how would that increase vertical and horizontal resolution in the center?
I sure do wish that the weird Frankensignal would've come to fruition.
@@StevenBradford I cannot definitively answer this question but with radio stations in the US there is a certain amount of bandwidth between channels called guard bands. When FM got the addition of HD radio they used a small amount of bandwidth on either side of the channels using a small amount of the guard band for the digital signal. The digital signal also takes significantly less bandwidth so it fits in the guard bands nicely. You can see what this looks like by searching on here for "HD Radio RTL-SDR Decoding vs Analog Radio"
@@StevenBradford Search "Combining Digital and Analog Signals for US IBOC FM Broadcasting" to find the paper on the topic by Bob & Bob.
This is fascinating, I thought the "HD" claim on these camera was dubious considering you could clearly see in the photos they were using what looked like a composite cable. It wasn't until I ordered one myself for a project that I was blown away by the quality.
(19:40) the digital formats (HD and SDI) do NOT simply "throw away" the VBI and HBI, they are used for ancillary data, such as control, test signals, and 16 channels of embedded audio.
Car backup cameras use some of these AHD formats with Android based head units. Really cool to learn a bit about it!
My dashcam uses it for the rear camera. It's 2K and is amazing for price.
I was wondering why my parents' car had analog artifacts in its backup camera feed.
Yeah i noticed that too. Which is fine especially when you use them at night and have a nice analogish high-gain videopicture with all the artifacts of analog video. Works really reliable which is why i don't really care for these radio transmitting car cams.
@@wwtoonlinkfan My parents' 2020 Toyota Prius backup cam has what appears to be 480i analog video in spite of its recent vintage. Maybe this is related?
@@wrentubes1886 I've seen aftermarket head units with composite inputs, so I wouldn't be surprised if even stock ones used standard 480i/576i or some other composite standard. Really, for a backup camera you don't need highest quality camera anyways, hell, some cars don't even have one.
There are some pretty exciting security cameras out there. I got to play with a prototype 3000x zoom with IR and night vision. We tried seeing how many fingers people were holding up behind a piece of drywall with moderate success.
I was under the impression that the 720p and 1080p "TV" security cameras were a scam, but seems like they're not. Good thing you did mention the stuff they produce is not ntsc per se, and they need a dvr. Really cool video!
Did not expect to watch a 30 minute video about analog HD signals, something I had no prior interest or knowledge of until now.
Very informative, excellent presentation, overall great work. You got a new sub out of me.
Working at a lawfim, I hate finding codecs for surveillance systems when needing to do editing. The worst is when the video player that the hardware requires for playback doesn't supply a way to export the video to a usable format. The worst is when multiple cameras record at 15, 30, and 60fps and try to .watch up angles. Pain in the ass.
Working at a court house, I completely understand. Evidence gets submitted, and you can't play it without installing codec of the month. Some of those come from really sketchy developers, so we require conversion to a "vanilla" codec. I've even seen proprietary .WAV files which I didn't think was possible.
Would a law firm pay someone to do this as a service?
@@FloydBunsen I would think so. Legal/trial support services is a thing. Some firms have them on staff, but many outsource the job. There are probably some serious NDAs for handling sensitive stuff.
@@TechnoTinker Yeah. .WAV is a container format. I was having fun playing around with a pirated copy of the Fraunhofer MP3 codec for whatever predated DirectShow as a teenager back on Windows 95 and using that to put MP3-compressed audio into .WAV containers. I forget if Windows 3.1 did, but Windows 95 came with several different codecs for .WAV by default.
@@ssokolow I think Windows 3.1 had about 5 codecs for WAVs, and I just took it for granted that they were always one of the standard ones until that security footage came in. I was really hoping that I could just change the byte for the format, but it wasn't that simple. Wikipedia has some good info on the container layout.
Cool video. I'm more into digital IP cameras than analog stuff, but it's the same companies in both arenas. One thing you might find interesting: The "generic" DVR you were using from Annke is actually made by Hikvision. There are a very small number of camera manufacturers and lots of companies re-labeling those brands (They call them OEMs). Dahua and Hikvision are responsible for something like 80% of all security cameras on the market, but through many different names (for instance Lorex and Amcrest are two big names in the US are actually just Dahua rebranded cameras).
I'm not surprised, just didn't know who the oem was - usually it's not a brand that actually has any market presence of their own, but this market does have the feeling of being remarkably concentrated on a couple companies
Security systems is basically a market of system integrators disguised as manufacturers (think of them like security equivalent of Compaq).
So here's the thing - I've sworn these HD over analog CCTV systems off completely. Way too finicky over time. One: after a few years if the BNC connections are even REMOTELY exposed to the elements (I've had some in attics even do this) then you get ghosting and signal loss until you clean/reseat the connectors. Two: If you try to re-use older BNC cables you will likely get ghosting. When I replaced a SD system with one of these HD over analog systems about half the cables were just not up to the job and had to be replaced due to ghosting. Granted, they were prob cheap cables, but the freebies that came in the kit solved the problem. I'm only using POE based IP kits now. You can pick up a nice Lorex kit with EIGHT 4k cams, the DVR, and cabling for $800.
Are you sealing the connector with an epoxy to keep water out, then wrapping high quality tape over it generously?
@@hicknopunk If you're going to go through that much effort, just flip to IP and be done with it. Most IP cameras come with a waterproof gasket to put on the end of the cable (8P8C connector) which couples to the camera's ethernet port. Analog just can't compete with IP.
any installation manual would have told you to properly install weather seal and moisture gaskets to cover all connectors.
I have a 20 year old BNC to VGA cable and it works just fine even after hundreds of unpluggings.
BNC is a good connector, just wrap something around it for outside use and it should hold up aslong as any other cable.
One of the reasons you don't see things like this used for general video use... Copy protection. Can't let consumers use something they could possibly record!
"...switching to fiber optics, which costs a bundle."
You bastard.
A very interesting and niche technology, and I thoroughly enjoyed the increasingly massive bundles of cable.
This video was quite interesting! I maintain and do installation with a medium-sized CCTV system where I work (about 80 cameras) and some of our cameras are still AHD in places where it wasn't cost effective to run network cable - the reality of new CCTV installations in 2022 though is definitely IP cameras. Their picture quality is far better, the cable runs are much more convienient over Cat 5 or 6, and you get the benefit of having a hub-and-spoke style network topology with off-the-shelf network switches. Need a new camera in a place? Well the cable doesn't need to go to the DVR, just as far as the nearest network switch.
And any ipcam plugs into the existing ethernet cable
One thing we found is you absolutely need to use super high-quality cable for network cameras. Any CCA will crack over time in outdoor use. Another is water proofing.
If any water gets into the connector it will fry the connector if not the entire camera. Since it's 48V. Damn near instantly.
While a analog camera will simply degrade in picture over time. I also saw an analog system have it's wires hit by a semi truck and there was no damage to the wiring. The DVR just got ripped through the wall.
@@mgzukows not sure if you really need super high quality cable, i run my system on regular belden cat6 and it works just fine for years, i dont use those cable that can cost more than $300 per roll (1000ft)
Water damage on connector can happen if installed incorrectly
What i like about IPcam is the ease of use and installation, since i only install for myself, having to buy 2 separate roll of different cable and having to worry which ones which is annoying, ip cam solve the issue since i can just use 1 type of cable for network and cameras, not to mention my home setup is spread across two location so analog wont do the job
And for the really crazy long runs you can just use an ethernet to fiber converter and run a 600 yard optical cable to the next building.
@@poisonouslead85 that works, one thing i dont like about that is that it doesnt carry PoE
This channel and Technology Connections should do a collaboration! My two favorite video technology TH-camrs. Your videos make me very happy, I’m a professional video engineer and camera assistant born in ‘96 so I got to see the technology evolve, and consider myself lucky in that regard.
Every video you make is just so fascinating. You and Technology Connections do such a great job explaining technology.
Fun fact: Triax based camera systems mostly operate with analog signals.
Triax camera runs can be many 1000's of feet at venues like stadiums or other large events, and the bandwidth often isn't there in the cable at that range for uncompressed digital circuitry, and you can't add compression to broadcast camera signals because any latency isn't acceptable to maintain audio & video sync.
Add in the needs for multiple signals in each direction, and the best solution is... analog RF. Most triax camera systems are literally a stack of very high quality analog modulators & demodulators in each end. Each camera chain is basically a tiny closed circuit 2-way cable TV system.
And you can actually send all the video/audio/control/etc signals over normal biax coaxial cables with a simple adapter that just leaves out the 3rd conductor of triax that is used for (very high voltage!) power to the camera.
True "digital triax" does exist, but it's rare and doesn't have the range of analog triax. ... Which is where the broadcast fiber optics come into play.
You have no idea how absolutely helpful this video has been to me! One of the things that is sold where I work are security/surveillance systems. Lots of people need much, much farther than what is offered with our kits. Now I know what these people need to go find. Thank you so much!
Make sure you research it first! I have never tested the distance claims.
Holy crap I wish I'd had this information around 6 years ago, my last job I was head of IT for a manufacturing plant. My team and I spent over a month pulling all the old coax runs and replacing them with IP PoE cameras; unfortunately due to the nature of the manufacturing WiFi was completely out of the question. This would have saved me so much time (and money probably).
Ive been installing security cameras for a while, I was amazed by how similar all the various analog formats are (even used the oscilloscope to try and figure out the technical differences), and how they just refuse to be cross compatible. Cheap DVRs that support every format were quite the thing to see when they hit the market, and the cameras that can switch formats even moreso. Very handy in fixing up old systems for stingy clients who refuse to upgrade. That being said, we switched to IP PoE a long time ago 👍
PS. there is a way to make these cameras look infinitely worse to the point they barely function, and its done all the time to save money in larger installations: trying to run the analog signal over twisted pair using baluns. Those who know, know.
Was it CAT 3 UTP as well?
i was on the industry long tome ago... cctv is and will be caos.. every vendor wants to use his standard .. in analog or digital.. nowdays i search for onvif compatible and poe..
Re: Digital TV - I grew up in a super rural area where when the DTV transition began there was no cable service. Many families had used Big Ugly DIsh solutions, ourselves included. Of course Ka band stuff had come along by that point but it has two major problems: rain fade and capitalism. There were many times local channels from the closest cities (50 miles) just were not available due to contract disputes between Dish/Direct and local companies. Rain fade was way worse, living in deep mountain valleys rain fade was plain unavoidable and it meant that during significant weather events -- times when you might _especially_ want local tv availability to receive information on the situation and progress -- we were almost assured to lose service. Throughout my youth, we had two coax outlets in the living room, the feed from the LNB and the feed from our 20ft pole in the field with a directional antenna pointed towards the city. Even in awful, lightning weather conditions we could get a weak feed from our antenna of the two local stations we were able to receive. After the DTV transition we were never able to receive them again. Even with a Blonder Tongue broadband amplifier you could never get a stable, watchable signal. You might _get_ a signal reading on a TV scanning, but when you watch it you'll only get blocks and interrupted audio every 3 seconds. Eventually Xfinity built out cable infrastructure out here (through public funding of course) and the issue was largely solved for those who can afford cable, but it was frustrating largely that our communications reception was essentially shelved in order to compress the television spectrum down and resell blocks to private wireless carriers.
The local HS also needs new microphones due to the 600Mhz block being auctioned of as well. Some things never change.
That auctioning of spectrum also happened to PAL bandwidth in Europe, but at least DVB-T and DAB transmissions reach almost everywhere, unlike your frustrating ATSC experience.
@@johndododoe1411 DAB coverage was awful compared to VHF Band II without significant infrastructure upgrades. DAB has already been shut down in Ireland, mobile broadband has better national coverage so it just seemed pointless. Meanwhile my FM radio from 1967 (with optional stereo decoder) still works fine
@@AaronSmart.online Problem is when VHF band II has been scheduled for auction.
one thing I am surprised no one mentioned, I believe you can run these over a single twisted pair using a balun at each end, as coax is difficult to terminate and thicker to run. Would be interested to see the distance they run at.
Great vid as always!
I was waiting for someone to mention the word "balun." When I was growing up, ham radio used baluns from 50 ohm radio feed to 300 to 600 ohm ladder line to the antenna. for security cams would it be 75 ohm composite to 100 ohm cat5 and back?
@@poofygoof standard video baluns go up to 600m because of cat5/6 impedance, while active baluns go much higher, ones that go up to 2400m (supposedly) but they need 12v DC. both types of cables can be used, but for long runs cat5 is preferred because coax is a pain in the rear end to terminate at the camera and doesnt really like bends.
@@poofygoof typical commercial video baluns would be termed a "current mode balun" by the hams I know, it doesn't actually match impedance, and you just eat the insertion loss. They're a common mode choke and that's all.
Here’s more food for thought. 480i component video is basically standard NTSC video split into 3 components right- luma/sync, and 2 color components. HD component video is basically just a sped up higher bandwidth version of 480i component. These analog composite component formats are most likely just HD component video converted to composite such as is done with standard definition composite and component video.
My mind is almost constantly empty, so I'm amazed every time you manage to come up with an interesting and engaging video idea.
I have actually got a few in the works, and now that I have a proper camera, these ideas will move along a whole lot faster because of that. Lucky me.
I love how in the week I've been thinking a lot about how far you could push composite, you put this video out. I don't know how you're synced with my brain, but please continue.
The reduced refresh rate probably is helping a lot pushing the higher line count over long cable runs at a low bandwidth. Maybe some pre-emphasis and notching of mediumwave radio stations to avoid interference to the picture.
@@PsRohrbaugh Ya the difference between higher end and lower end DVRs is how many channels they can run at what framerate.
So I completed 3.5 years of training at a German company that specializes in safety systems.
With various major customers who have used analog, digital and a mixture of both for their video surveillance systems.
We mainly distributed Axis and dallmeier cameras.
1. If an analog system is already in place and you want to switch to digital, it's better to use an encoder. But these are not cheap. An example would be "AXIS P7304" for 1080p.
You would continue to use the analogue cameras, which would be recognized as digital cameras because of the encoder. (Also, I've had the experience that the analogue system lasts longer than the digital one. At least in the professionell area.)
2.
The advantage of RJ45 (ip) is that no additional power cable / control for PTZ control or audio to the camera itself needs to be drawn since it can be supplied with power via POE (POE+).
it saves costs by eliminating the power line and eliminates one possible problem source per camera.
In addition, cross-location video distribution is possible via vpn .
3.
If the range of CAT6 at 100 m is not sufficient, we used fiber optics. This requires a converter which requires an additional power supply. However, this has the advantages of an electrical separation, which customers appreciate when ther camera is mountet oudside and the recorders are in their server rooms dirictly cnectet to the ouside. (Lightning strike)
4.
The resolution of a camera is rather uninteresting. What is more important is the pixels per meter. Means a 4k camera that is completely zoomed out and should recognize someone who is about 200 meters away is completely useless. whereas a properly oriented/placed 720p camera would do a better job.
(There are guidelines that specify how many pixels per meter are needed for different degrees of identification.)
Besides that, it depends on the bandwidth. Both for storage and transmission frame rate.
t
I was actually really surprized, when I realized, how little analog signal need to function. For PAL signal you only need around 50kHz of bandwidth to grab on that sync and see some blurry shapes. I was able to record video signal over soundcard at 96kHz sample rate and got flying ball instead of DVD logo, but it was really impressive for me to see, that it has sync and i can see anything at all
I've heard of people pulling off analogue TV reception with RTLSDR recievers (which can do a 2.8MHz sampling rate) and getting recognisable (if blurry and monochrome) pictures out of it, but I never would have expected you could go as low as 96kHz and still have it work, however badly.
@@Roxor128 I think blurry is an understatement. By my calculations you'd have less than 6 pixels worth of horizontal resolution.
That seems really unlikely. The horizontal refresh rate is 15 khz, so at 96 khz you'd have six samples per line, or six lines of resolution.
@@VPWedding 5px is enough to roughly see a bouncing ball. And as the sample rate isn't divisible by the scan rate the sampling phase will change each line, probably increasing the effective resolution.
30 year instrumentation and mechanical journeyman here,,, and I have been a property owner since I was 23. I also am a gearhead/carguy. As such. I am self taught on cctv systems that range back to the Zmodo junk that was on ebay in the late nineties and showed grass and trees to be PURPLE!!.
I didn't care about the colors because I was just trying to catch trespassing thieves.
I just subbed because you are the first person I have discovered who has addressed this subject matter in a cohesive manner.
THANK YOU SO MUCH!!!! I am thrilled to find your channel!
This might be a consumer variation of the 960H trick you mention.
Commodore introduced a Super-Hires NTSC (and a Super Hires PAL). mode with their Amiga 3000 in 1990. It gave you 1440x486 NTSC 35ns display mode. With the enhanced chipset (ECS) it was limited to 4 colour mode.
When Commodore released the Amiga 1200 & Amiga 4000 in 1992 with a new chipset (AGA - Advanced Graphics Architecture), it was capable of using 8bit planes and a 24bit colour palette in all resolution modes including Super Hires NTSC (and Super Hires PAL) mode. HAM8 could also be displayed in the Super Hires modes, simulating an 18bit colour display with a 24bit colour palette.
I like this guy. Clear explanation, easy to watch and good editing. I feel a technology connections collab comming..
Historically, Ethernet ran over that RG-58 coax, known as 10-Base-2 or "Cheapernet" because it was cheaper than the heavy RG-8-like coax used for the original 10-Base-5 Ethernet. All of these were 10Mbit/s with CSMA/CD bandwidth management. If those Ethernet converters provide more than 10Mbps over RG-58, they probably use a different data encoding than the original crappy 10-Base-2 signaling.
This would be 10Mbps max, as its a shared bus/cable (so no separate send and receive lines) and would need to be able to fix the Video stream and any commands/diagnostic data. Would be possible, but probably only at SD bitrates, in which case, analog signals would be fine.
Actually this was useful...I've an aging pal galax 960h system here in the UK that's been in service for well over 10 years now and want to "upgrade" to a higher resolution system....thanks dude.
I belong to SMPTE. The ITU-R Rec-601 is 720x486@270mb/s. Fun fact it was called CCIR601R before that, and was a parallel (NOT serial NRTZ) digital signal over a 25 conductor DB25 cable and connector!
Look it up! the cable was super low capacitance (something like
Yep. I have a Sony D-2 deck in my basement with a composite digital parallel connection. Super fun thing was learning that even though you can use a parallel to serial converter, it's still composite. All normal serial digital is D1 component. Had to get a format converter to change it from D2 parallel to serial then to SDI (D1 component).
Dude! When i worked in live productions, small home security installing, and managed an electronic stores I was always taught HD could only go like 50 to 100ft before the signsl would break up, analog or digital (yes to those asking digital breaks up too by having digital snow and crazy picture, its not as simple as its there or its not like most people say.) This is so awesome!
Addendum: ive never seen a tech youtuber tell the truth about a digital signal till you did. You showed what it does! No one ever believes me because everyone is like "see this article says its on or off and you don't need any of those special cables you can youse a coat hanger"
About the Ethernet-over-Coax-Adapters you talked about at 11:38
These (or at least the cheap
Here in Romania one of the major ISPs had internet service through Coax using cheap Ethernet-over-Coax equipment. I think the whole line maxed out at 150 Mbits and at least 10 people would be connected to it, meaning speeds were not that good. But now we got amazing fiber which is much more reliable.
@@RaduTek It’s really common for almost most places in the US to have cable internet as well. Lots of places can’t even get that and have to use phone lines
Ethernet cables were often coax in the past anyway = 10Base2, with 'token ring' plugs(the same plug as many security cameras use), so I'd imagine converters have been around a long time, although speeds were lower then.
@@FloydBunsen Yes, but that's a different system called DOCSIS. The one we had was inferior in terms of quality and performance.
One of the cheapest option for these coax adapters is "DECA"... the in-home adapters, meant to share coax with cable TV, overlap with satellite frequencies. DECA adapters are meant in turn to share coax with satellite systems, and will scramble/be scrambled by cable TV. If you're using them on plain coax, the inability to mix with cable TV is no longer a downside.
Hi. Thank you for the interesting and informative video! I had been under the impression that "960H" meant "quarter 1080p" or 960x540p. It looked to me like they were using confusing terminology to trick people into thinking that 960H was higher resolution than 720p, when in fact it was significantly worse.
I _do_ know what the "486 lines" business is about. The standard designed in the 1940s had 525 lines. 486 if these had actual picture information, while the rest were black, so as to give the electron beam time to get back to the top of the page. When JPEG was invented and applied to video, it was observed that JPEG required interlaced video to have a line/pixel count divisible by 16. By pure luck, PAL's 576 on-screen scan lines matched this, but NTSC's 486 lines did not. Rather then waste data recording an extra 10 blank lines, they decided to remove 3 from the top and 3 from the bottom, thus creating digital-NTSC's 480 lines of resolution. These lines were in the "overscan" area and would not be visible on most sets anyway. This also explains why NTSC has this strange even-field-first scanning pattern for interlace. What we are calling line one today was actually line four when 486 of the lines had actual visual information.
I actually used a Hikvision IP camera as a webcam
But it was 2020 and I fit CCTV so had some spare ones
To be honest I have never used the analogue HD systems I went straight to IP once it became cheap enough
I have used the SD analogue encoders though (like that Axis P7214 on your desk at the end) they work well when upgrading old systems but want to keep some old coax cameras working
Hikvision did dabble in digital HD SDI cameras though. I bought one a while ago and the image is actually nothing like a security camera. its a semi broadcast quality 1080p image as its not doing much processing to the image for even-exposure
The only commercial systems I've worked on were all IP cameras with strategically placed switches to keep the wires short enough. Never occurred to me before that analog would've been used prior. Neat.
There's another major advantage of using analog video: You effectively have zero latency (provided there are only analog components in the chain). That property is sometimes 'exploited' in things like theaters, recording studios and orchestras where the conductor may be in a different place than the musicians and the performers want to see the conductor without any lag.
I remember you asked for solutions on Twitter, I had no idea this existed! HD over component is mad, I love it.
Thanks! Ive wondered how they did this since i first installed one of these HD surveillance systems several years ago.
Turns out they just turned up the bandwidth limiit on plain old NTSC to get more horizontal lines. And more resolution on each line. Cool!
And nothing anyone could put a patent on.
It remind me of the first NHK hd cameras and recorders in the 80. Those were analog RGB, 10 Mhz for each color channel, 30 MHZ total. Standard def was less than 6 MHZ. That caused a lot of skepticism about hd broadcasting in the beginning as we would have had to open a whole bunch more channels at the same time cell services were looking to expand.
The green screen effects on the surveillance footage are out of this world! Thanks for your efforts, we see them and they are amazing :)
I got a good laugh out of that, especially with the perspective being about 90% correct so those who wanted to see it was a bit wonky, would, and those who didn't, wouldn't.
Super fascinating. I'm a bit of a HD+ analog nerd and I had never heard of this. I've been doing a bunch of work with 1080p composite. I've also been sketching out extending composite to 4K. The numbers work, but it's really pushing bandwidth constraints, and that's over 3 cables. Even with the chroma subsampling that you get in composite vs. component, doing 2k or 4k over "NTSC" is batshit in terms of the bandwidth you're trying to cram down a single long wire.
In fairness, your HDMI->HD-TVI->HDMI test was using a very difficult test pattern. In the analog domain all of the hard edges in the grid lines of a test pattern will highlight bandwidth constraints from parasitic capacitance, or just poor PCB layout.
A few years ago I did a video comparing a cheap Component to HDMI adapter vs. one from Blackmagic. The difference in engineering is staggering. So much thought needs to go into the analog domain to avoid the smearing issues that you saw.
Good video! I had no idea that this kind of HD analog video was a thing, I figured at the beginning that it was going to be some kind of rf signal since that can go pretty far in the right kind of coax, but I didn't expect it to be roided up NTSC 😆
As part of my job, I occasionally install security cameras, and as you guessed everything commercial is IP-based, kinda boring. However, usually to run long distances (like between budings, or even multiple campuses, assuming they don't already have cable/fiber between sites) we use point-to-point wireless IP Bridges. You can get a consumer kit for under $200 that can pretty easily handle two or three 2K video streams at a thousand feet, and if you get the "spare no expense" commercial stuff, you can span literal miles at gigabit speeds or higher! Setups like these theoretically have a potential to lose data more often, but a properly installed commercial bridge can go for years without interruption or downtime, effectively no less robust than running fiber or cable.
Hey, I'm a security camera enthusiast! During most of the beginning of the video I kept yelling "IP camera" at my phone, and I'm glad you brought them up. They really are the answer to this problem. You're right, the cost can be expensive, but there are ways around that, I work for a company that solves this whole problem for our customers. But great video overall. By the way, Hikvision is pronounced hike-vision, and Dahua is pronounced dawua, you don't pronounce the "h".
Jesus Christ finally someone who's got it right on digital TV, thank you Gravis. I've really tried to make a point to folks about this social issue aspect of it, and how it made watching TV markedly worse, overwhelmingly for the poor, but you've put it so succinctly in one sentence.
I think a lot of the reason people push back on this is just because an awful lot of people *don't see it.* I've talked to folks who have had a perfectly fine time with ATSC, and given that TVs are generally, you know, fairly stationary, if it works once, it'll keep working.
@@CathodeRayDude yeah that's fair, a lot of people never had to deal with awful aftermarket shitboxes, which I think is still the dominant experience in poor countries where people couldn't prioritise buying a new TV. Those are dying off now, but at least here everyone still clearly remembers how responsive and reliable even the worst analogue tv was compared to the landfill garbage used for DVB-T. At least we still have Teletext, for what that's worth lmao
The thing is, coax carries the data from the satellite dish to the box, or from the aerial to the box, but HDMI is needed from the box to the TV. We know coax can carry all the data required for HD signal over a long distance, because it does that in every house.
Both HD satellite programming and broadcast HD use digital modulation schemes, while these security camera standards are using baseband video... going from "a solution exists" to "buy this product" is engineering, and I think that's what this video is appreciating.
RG-59 coax is typically used for CCTV systems (baseband video, not RF), it's not good enough for UHF or satellite TV at any length (ok for a fly lead but that's it). Coax good enough to connect your satellite dish is a lot more expensive.
I've found that you can even run HD-TVI signals through a single twisted pair of wires.
I've got 4 cameras on my parents' barn all running through a single Cat-5e cable that we trenched underground nearly 20 years ago (with the intent of eventually using it for data or telephone, but hadn't utilized until I installed the cameras in 2017).
The 4 signals travel through more than 400 feet of standard UTP Cat-5e cable, yet it's surprisingly clear (despite my ham-fisted install job using old screw-type terminal blocks).
I'd always wondered what the technology behind it was and your video really cleared that up for me. I greatly appreciate your work in creating this (and all of your) interesting video(s).
I actually own a business and do cameras/networking/production for a living. I typically use IP cams. So far, my longest run with an IP cam was 508ft through a single CAT6. Camera has worked flawlessly at 4k 15FPS. Also I've ran component video over 175ft through RG6 coax terminating with RCA connectors. Works great but it is rather bulky with 5 runs going to every device
Component video is amazingly tolerant... short runs to a newer TV that uses a TRRS adapter can be extended with a 4-pole headset extension! Then again, I did use a gold-plated headphone cable, that's potent homeopathy. 🤣
I work in enterprise I.T. and and have lots of experience with CCTV.
I gotta say, man. I love your videos. You're very well spoken. Your format is never short-form and you're very detail oriented.
You deserve all the subscribers and views in the world! Please keep making your content. I'm giddy when I see a new Cathode Ray Dude upload.
Seriously - Love your content. Thank you for uploading!!!!
AHD/TVI was used in a video transmission system for drones then called Byte Frost by Fat Shark so that's where I first read about it. In subsequent iterations of the hardware they threw away AHD and went with MIPI-CSI with a proprietary handshake protocol.
Oh and also all analog cameras for FPV drones such as Runcam/Foxeer/Caddx are basically repurposed security camera sensors with slightly better lenses. FPV wouldn't be that dirt cheap if not for the security camera stuff.
Yeah, our hobby was pretty much entirely analog SD well until some three years ago when DJI released their bonkers digital HD transmission system, but that's for another story.
I loved this! I always wondered how new cameras were doing "HD" over a BNC/analog type connector - this nailed the explanation - great job!
Thank you for creating content with original research and sharing your honest hard work.
I feel the need to correct things: digital signals can travel much further and longer than analog signals fom the pure signal transmission side. It's the implementation on the sender and receiver that sucks. There are implementations that lower the bitrate and get a perfectly good signal (e.g. in modern RC rx/tx) with whole lot of algorithms and ideas. That is just not implemented in TV stations, since they are designed to cover a given radius.
Or radio for that matter. For the exact same reason no less. But are they implemented for mobile internet transmissions?
It's really weird that the artifacts you get with composite like the dot crawl and crosstalk aren't that much of a deal breaker at higher resolutions. The moment you switched from the usual composite 480i, it's perfectly acceptable.
Same reason dot crawl wasn't really a problem with a portable 5 inch CRT: you can't see the individual dots anymore they're too small. More dots or less screen, same result.
26:30 interestingly, the most noticable distortion was actually the fish eye lens and the effect on your gesticulations.
Variety of video sources on this video is exceptionally bizarre. Nice🙂
Love this! I was very impressed with the quality of the footage when we installed our security system, and was interested in just how it was doing this!
Definitely agree that these things work fantastic for the very low cost.
From the coax cables I always assumed HD surveillance systems were using something similar to ATSC QAM or DVB-C (basically a small cable TV system) to get around the distance problems.
I am an electrician with extensive security and surveillance experience. And to other electricians, I am a nerd. As such, I came for the tech and was captivated by the history behind the tech. I do remember 960H, but it was very fleeting before the digital takeover. I still install NTSC coax cameras for their resilience and when necessary, I convert the coax to EOC (ethernet over coax) and then use a switch and IP cameras. But analog, as you said, it is far more robust and for the price is still a very good option. Hybrid systems exist so you can retain your older but still useful cameras and update with 4K ones all on one system.
I do believe the makers of these cameras make them hard to connect on purpose so people don't steal these cameras to use them for something else
This is just fantastic content, keep up the awesome work my guy!
I was always wondering how those coax cameras can go up to 4K
Not only did I NOT seek out a half hour of imaging tech info, or to give ti my best focus this week, but I had stuffs to DO man, this held me hostage. Thanks for the excellent presentation.
Two things come to mind having watched this. The first is that if they did this over S-Video, most of the degradation problems would go away, but the technology wouldn't have to change drastically (S-Video can be converted back to CVBS at the destination passively, though using transistors looks better). The second is that cramming more horizontal resolution in the signal was something that many games supported on the PS2, Dreamcast, and GameCube. I think there were a couple of PS1 and N64 games that did it as well. Usually you'd have to hold a button while the game booted, though sometimes the code was there but inaccessible without a GameShark. Often, these were artificially limited to component/RGB cables because 960x480i over CVBS wouldn't be supported by most TVs, even those that supported widescreen, but that's not always the case. The PS2 can be configured to try to shit out 1080i over composite if you wanted (though this wouldn't work without a processor that supported custom timings). We got so close to an analog HD future, but it just didn't materialize.
Changing to s-video would require using different cables, which would defeat the purpose in many cases.
From memory the oldest game consoles did the reverse with horizontal resolution, outputting less to make processing easier.
I was planning to augment my home automation setup with some IP cameras, and I'm so glad I didn't. Thanks for bringing this to our attention
For the cable itself, fiber could be much cheaper. These specs are like overclocked NTSC analog.
Love your content. We seem to have similar interests in old tech...lol. My wife looks at me cross eyed every time I go to Goodwill
Really interesting. I always wondered why "regular" composite never got even a tad better.
Bandwidth limitation. It had to fit within a 6Mhz broadcast channel signal allotment. If you tried to go higher there’d be interference with adjacent channels. DTV made it possible to use digital compression to fit HD channels in the original 1940s channel width assigments.
But with a cable you don’t have that bandwidth limitaton.
@@StevenBradford Also of note, most PAL countries had wider channels. 7MHz in Australia, 8MHz for most of Europe and China. 6MHz PAL channels were quite unusual and only used in a handful of countries from South America.
For coax (antenna/cable) I can understand that, but for composite signal or s-video?
This video is not only very interesting, very well made, with excellent research (as usual in this channel), but super useful. I was literally wanting to know more about this technology and this was a very didactic approach. Thanks very much and keep the awesome work!
The digital tv thing being a poor tax is 100 percent. And when we moved to internet tv all the companies have been slowly jacking up the prices to just make us go to cable. Hulu live tv forced us into the disney plus bundle this month.
And here in Rhode Island we get Fox 25 from Boston more often than we can get Fox 64 out of Providence. They turned down the power on all our transmitters to make the antenna useless.
Those cheapo usb dongle capture cards make great webcam and old console cards. They do 720p 60 no problem.
Boston is far larger and richer and more important than Providence, so of course their antenna tower will have a stronger signal. If what you say is true about reduced power on RI transmitters, complain to the FCC or your Democratic representative.
really good video, It was Greek to me before but you opened up my eyes
There is hdmi over ethernet too. Have converters on both sides and use ethernet in between
It's hard to find good ones though. We put those in a few client places. Since essentially the max for an HDMI is 75ft with a built in amp.
They fail way to often to be used in commercial applications. Unless you go real high end.
True HDMI over ethernet is distinguished from HDMI over twisted pair extenders... ethernet converter systems often have extra bells and whistles, like passing IR remote signals. These units tend to cost around $100/pair, and in fact are generally compressed MJPEG or H264 in RTP/UDP/IP on ethernet. They can be set up as a relatively low cost video switching system using a managed ethernet network switch, placing as many receivers as you want in the same VLAN as the transmitter.
Doing this with the cheaper, simpler to find HDMI to twisted pair converters won't work, and may damage the devices if you try.
Wow, I was literally looking into this same kind of thing about 6 months ago. Didn't chase it to the same extent you did, but ultimately came to similar conclusions about usefulness versus other options for my application. I wish I had seen this video first, though, because it would have saved me a lot of time researching.
AHD/TVI/CVI are pretty much the same but have different colour subcarrier frequiencies, and also the subcarrier is above the luma i think, rather than overlapping like PAL/NTSC
Im cofused as to how that would work. Do you mean the chroma signal is in a different section of the signal from luma? In which case why would you need subcarrier? As pointed out by CRD in the video, the signal looks like NTSC on a scope.
@@StevenBradford What??? How would you otherwise transport Luma and Chroma on 1 cable if u didnt have a subcarrier?
@@willyarma_uk As I understand it the chroma is “overlapping” the luminance. The subcarrier burst is in the horizontal blanking but doesn’t have the color in it. I think i was just misunderstanding what you wrote.
@@StevenBradford Ahh right, no the colour busrt in the blanking period is just for synchronization. The chroma is quadrature amplitude modulated and then summed in with the luma. What I meant was I think the the frequency of the subcarrier is quite high so it dosent overlap the frequencies of the luma as much.
I appreciate the many times in this and other videos where you fade in footnotes that aren't important so the script glosses over them, and I'm not one of the people who are going to pause to read it all, but it does communicate the degree to which you're simplifying a complex subject so I can intuit the degree to which I'm not leaving this video with a deep understanding of (some of) these subjects
CCTV Installer here (europe). We install 4k and 8k IP cameras daily. FullHD or 2k is basicaly obsolete in this buissnes. It's actually pretty scary beacuse most of Hikvision, BCS and Dahua (biggest players in the industry) cameras have face and number plate recognition chips onboard, only the cheapest ones don't and we rarely see that clinets want them. Pretty much every hotel, shop or office with modern CCTV system is running them and they see everything in freaking 8k (though 4k has more quality playback for some reason but i quess it's sensor size problem).
Welp I'm afraid now
But wait! There's more:
Security of those cameras is bullshit. If you can see the camera (and sticker on it with serial #) you can literally ask HikVision or BCS (dunno how's the situation with dahua but i quess its the same) for one time master password to reset the camera (yes, SN needed for resetting the camera is literally on the sticker on housing :) ). You have to be registered as installer and shit but i bet there are registered people who will send that email for you for $10. If you have access to the LAN/WLAN you can find out cameras' IP adresses and reset them, do whatever you want with them and set the old IP adress so the recorder is still recording like normal. Recorder is dumb, it doesnt know what is going on with camera, the camera just sends video over IP and thats it.
And there is that thing that even when someone is watching playback on screen they propably wouldn't notice the camera went offline if there is little movement in frame, because the playback just hangs on last frame that went through. So you can cut the UTP, connect camera to switch, splitter or something and propably nobody would notice. Also, those cameras freeze on day to day basis so if the playback stops, security guy propably would not care. Even those hardcore mall-cops don't care, its bad.
Analog cctv is more secure 👌
Wow. So is this long distance too? So if iphone 13 pro has a 12MP camera, which means a 8k ip camera in theory could easily transmit it long distance? I wonder what components would one need to build to have a hardware/software based solution that does the conversion digital -> analog -> digital and carry 12mp (or 3x 12mp cameras)?
What is the example part# for the 8k camera?
And one more question. If someone let say had a "Sony A7R IV" with 68MP camera, could this technology in theory be able to sustain the signal over cable, or you would hit some max carry frequency?
@@MrInterestFull this is not so much about how many megapixels does sensor have as about bandwith and bitrate of your stream. You can have 100MP sensor and only make 1000kbps video out of it.
I actually do this for a living lol. I regularily build hikvision cams, though im thankful most of it is ip. What you mentioned of replacing old cables is costly, isnt that much a deal in reality, in fact, if a company already wants to put in surveilance, and have a large area to cover, they got the money. Stil, very interesting video!
10:25 There were two (at least partially) analog HD video formats : HD-MAC and Hi-Vision/MUSE :
en.wikipedia.org/wiki/HD-MAC
en.wikipedia.org/wiki/Multiple_sub-Nyquist_sampling_encoding
and 819 line. Analog HD but black and white.
@@debranchelowtone Most TV sets weren't good enough to show an improved picture in 819 lines than in 625 lines.
There also was a 1025 line project at the time the 819 line system had been adopted.
@@chucku00 Sure it was far from perfect, cameras had their limitations too. The experimentations started in 1941 with more than 1000 lines. By 1970 until the end in 1985 almost everything was shot in 625 lines and optically converted to 819 line. So it didn't look good at all during the last years.
HD-mac appeared later. Very interesting one too.
@@debranchelowtone Je bossais à la FNAC quand les expérimentations HD-Mac ont eu lieu en 1992 pour les JO, avec le fameux téléviseur Thomson Space System. J'ai connu le 819 lignes jusqu'en 1983. Et franchement, mis à part la meilleure réception en VHF qu'en UHF là ou je vivais, je ne voyais pas trop la différence entre 625 et 819 lignes.
Back in 2008 I had a tour of the video surveillance system in a large casino. All of the cameras ran over coax, for a specific reason you didn't mention - no digital lag. The timing of the video signals, and the matching between them and all of the other systems recording exactly what happens when, is critical to how they are used in a casino environment - to identify and catch cheaters in the act. As I recall, all of these video signals were brought in over coax and then split between the live control room (where they had the pan / tilt / zoom controls), and the recording facility which in the day had dozens of racks, each of which had dozens of RUs of USB video capture devices - each of which took one analog signal in, and converted it over USB into a device that would record the output and then pass it through to the digital storage that was again all separated from those capture devices. It was fascinating stuff for me at the time, and a complete eye-opener as to the different priorities that dictate how video surveillance works in this type of high-stakes environment. Thanks for your insights - and I hope that one day you might find one of these decades-old devices being sent out to pasture, and you can rediscover this weird transient technology from the day!
Hah, analog wins again! Digital over any amount of distance always seems to be worse than analog in terms of robustness, at least in my experience. The worst offender I've seen is digital "HD Radio". Trying to keep a digital AM/FM signal while driving is rough. So rough that being able to seamlessly switch between digital and analog as conditions worsen is a big part of the standard.
Really fascinating video, I really enjoyed it man! Thanks!
With wired connections, digital can go pretty far and still be robust. Wireless transmissions, such as TV, radio, and Wi-Fi, on the other hand... Analog does so much better in that front.
Great video, bet this is gonna be one of those channels that blows up. A/V and other cable standards are fun to me
I feel like if I were to set up a security camera system I'd just use IP, just because I have so much ethernet cable lying around, and repeaters, etc etc are a dime a dozen
2:24 Waaaait a sec. What's going on with that logo there? It shows up on the wall in the video and on the wall on the monitor in the video but not on the wall in the monitor in the monitor.
I TRIED to nest it again but it was just too much lol
Thank you so much for this enlightening video. The challenge of pushing video over long distance cable brings back memories of the days of broadband internet over POTs line - ISDN / ADSL and other other technologies predating cable and fiber. How much bandwidth can you get out a twisted copper pair to your telco - a lucky few get 1 megabit or more while most contend with far less. Thank goodness we went pass that in pretty short time.
Before I watch i'm gonna guess its CCTV AHD/CVI/TVI. Lets see if i'm right!
This was strangely enjoyable to watch from start to end. Thank you!
This explains why my crappy Swann home security system uses what appears to be coax, and why one of the cameras always seemed to have faint coloured bars scrolling down it. Never really thought much about this. Great vid!
Im reminded of a conversation with a classmate who was researching computer vision systems for traffic intersections, who mentioned that there was competition between analog and digital TV signals. I remember scoffing at that as obviously outdated information (partly because I forgot an entire era of A/V equipment and imagined like a vidicon tube...). I would be willing to bet that's what this technology gets used for: sending HD video over a wire from a traffic intersection to a computer to run a bunch of complex computer vision math, and its all just NTSC!
The closest we have today is VGA. Which is surprisingly high quality for a analog video format. With WXUXGA you can get 7680x4800 and honestly if you put it side-by-side with HDMI on a normal lenght cable you wont see a difference hahahaha.
Most people like to say that VGA has loss of quality but I never saw someone actually prove it. Because if there is, its pretty minimal, and most of the time can be blamed on the converter. The major problem is that VGA can suffer interference by being analog. As said, on analog the interference is just plain added to the picture, while HDMI, or the better DisplayPort will black on interference but its really hard to have enough interference to black a 15ft HDMI/DP signal, while its not that hard to have some imperfection on 15ft of VGA.
Also, theres the major problem that the driver on a moderna LCD is digital, so you're most of the time converting digital to analog to digital and back to analog to drive the pixels. Manufactures dont want to add the cost... Thats why today less and less TVs come with composite (they exist, I swear).
👍👍, I have a tower and HP VS19E (VGA, 1280x1024@75Hz) monitor and a couple old laptops with 1920x1080@60Hz eDP/LVDS displays and when I put them side by side I can't tell the difference they all look really good to me but I also have a high quality VGA cable and my current graphics card is from Gigabyte (a Radeon HD 7750 2GB)
It’s not surprising at all that coax can do analog HD: coax handily carried dozens and dozens of analog SD channels simultaneously. So the analog bandwidth is there. The HD security standards are simply allocating all of the available bandwidth to a single signal, rather than dozens of signals, and thus that single signal can itself have a very large bandwidth.
Digital absolutely can be designed to degrade gracefully. On the one hand, we use error correction encodings to add redundancy, but moreover, the reason digital signals tend to fail badly is that they’re compressed (which makes them very un resilient) and often encrypted (which will often simply break the link entirely when errors occur).
The audio CD is a great example of very resilient digital encoding. The analog waveform coming off the laser pickup (typically called the RF signal because of its frequency) shows how much variation can be tolerated before the digital circuitry can’t make it out any more. But then the encoding (EFM and CIRC) enable both bit errors and block errors to be corrected (which is why minor radial scratches don’t cause any problems). And then even if a particular frame of audio cannot be recovered, it can either be dropped (causing a minor audible glitch) or interpolated (causing a bit less of a glitch). But this works because a CD is the exact opposite of compressed: the raw audio data is actually inflated with an extra 75% of redundancy data.
The attention to detail at 2:23 to put the T-Mobile logo on all the different camera angles is unreal. The reviewability of your videos is unmatched