good info! i'd encourage everyone to watch the whole thing but if you're in a rush... 1:03 What is SDI? / History Of SDI 5:57 3G Level B - Dual Link 7:14 3G Level A 10:58 Caveats to using HD-SDI for 1080@24/30 12:29 3G Level B - Dual Stream 13:32 6G and 12G
Great video Doug, I was always wondering about Level A & Level B SDI. Thanks for clearing that up. For anyone thinking of becoming a Patreon it is WELL worth your time, especially if you are in this kind of industry, or even just interested in it.
Very well explained thanks. Could you do a video explaining “gen locking”, ref in, Black burst etc. I have a rough idea of what it’s all about but when do I need it? I have a BM television studio HD and a few BM studio cameras do I have to use gen locking? Thanks again!
Doug Johnson Productions thanks anyway. There doesn’t seem to be a lot of info out there on the when and why. I just really want to know what I’m missing by NOT using it! Great work by the way, I always learn something from your vids.
The biggest difference you see without using genlocked cameras is longer delays from the camera to final switcher output. Without having synchronized sources the switcher has to delay all incoming video sources by up to a half a frame to make them all match. If you run in a genlocked environment that delay is eliminated.
Doug Johnson Productions OK I can understand that but is half a frame delay really that noticeable? Is the delay different for each camera and dependent on cable length or something? Thanks for the help, it’s much appreciated :)
That depends on several factors, most significantly the frame rate. (Cable length is not one of them.) If you're shooting, say, at 24 fps, any two cameras could be out of sync by as much as 1/24 of a second since they have no common source of synchronization. If you're dealing with a fast moving subject, or a source that requires precise synchronization with audio, that 1/24 of a second could be noticeable when switching between those cameras. And if you're projecting the video live that extra delay from having unsynced cameras might be the difference between the delay being perceptible vs. not. Shooting at higher frame rates like 60 fps can help minimize the perceptible delay, since the maximum difference between the start of the frames of any two cameras would be 1/60 second instead of 1/24 second.
Im a bit confused with SDI existing in the late 80's. However, I don't recall seeing it on any gear up until the late 2000's. At the time even tv stations I was working at, just used analogue SD over BNC connectors. Was it just a slow implementation as the rollout of HDTV took a long time?
Pretty much. In a lot of situations there wasn't a huge pratical benefit to switching over from analog to digital, so existing analog systems just kept getting used. SDI would have given a cleaner signal, but not as big of a jump as going from SD to HD.
Sometimes you'll find it in product documentation. But not always. Blackmagic Design does everything using Level B. Sony camcorders also use Level B. Professional ENG cameras often use Level A. And most other manufacturers tend to use Level A. Newer Blackmagic Design equipment (from about the last 5 years or so) can accept either Level A or B, and often lets you choose which of the two it will output.
Hope you can help. I was in video in the analog days. Now watching your channel I am looking to convert from a NTSC Hitachi C1 video camera , to SDI. I bought a AJA D10AD and the Decimator MD-HX. The dip switches on the AJA and the menu on the MD-HX are confusing. Wanting to view the camera video through HDMI on Samsung television. There are no videos that walk through this set up.
From what I can tell the Hitachi C-1 doesn't have an SDI output -- just composite video. Your AJA D10AD should be able to convert the composite video from the C-1 to SDI. And then the Decimator should be able to convert the SDI to HDMI. I don't have any experience with the AJA converter. On the Decimator, start in the Control menu, press the Enter button, then use the left/right arrows until you get to the HDMI Source screen. Press Enter repeatedly until SDI is selected. Alternatively, many televisions support composite video. Check your manual for your television to see if it does. Depending on the model it may require an RCA-to-1/8" plug adapter, which likely would have come with the television if it does support it. If your TV can accept composite video, all you'd need would be a simple cable to go from the video output of the C-1 camera to the composite input on your television; the other adapters wouldn't be required unless you have a specific need to convert to SDI or HDMI.
hi i im using SDI cable to livestreamg and i using 50 feet long SDI and i have issues went i transmiting the screen go on and off and i have been with that problem since i get the camara including the cable please any advice will appreciate thanks
That sounds a lot like a bad cable. Is the cable you’re using 75-ohm, like an RG-59 or RG-6? Is it a high quality cable with good shielding? Is the cable and it’s connectors free from damage? One way to see if it is a cable issue is to connect the devices with a short cable to see if you still have the dropouts. If they go away, you need to replace your cable. If it still has dropout issues, one of the devices has a problem.
1080p25 falls within the HD-SDI spec, so 3G shouldn't be coming into play. Make sure your camera and switcher are set to the same video format and frame rate. And make sure the camera is actually outputting 25p, not 50i.
You mentioned Sony only does Level B, but that is not entirely accurate. If you use one of our Studio Cameras capable of 1080p, like the HDC1700 or better with 3G activated, then you can choose Level A or Level B when in the 3G format. To select A or B when in the 4K mode, you would select this from the 4K output menu or on the RCP.
Thanks Doug. Very well explained. Another question for you, what is the differentce between progresive and Psf signals and if there is a difference in quality between the two? Thanks
PsF (Progressive Segmented Frame) is a technique of wrapping what starts out as a progressive video signal into an interlaced output signal. It isn't a discrete signal type of its own. The format of the output looks identical to any interlaced signal. Using PsF you could, for example, shoot at 24 or 30 fps, and output that video over 1080i. The "segmented frame" portion of the name means it splits individual frames across multiple fields of the interlace video. So a 30fps signal could be converted to 60i by simply splitting the odd and even lines into separate fields in the output video. In the distinct case of 24fps being wrapped into 1080i60, something called 3:2 pulldown can be used, where frame 1 of the original video is stored in 3 fields of the output interlaced video (each field containing half of the picture vertically), frame 2 is stored in the next 2 fields, then alternating back and forth thereafter. Video devices which are equipped to process PsF can reverse the process and reassemble the original 2 frames from the 5 fields, without any loss in quality compared to the original. For 30 fps material wrapped in 1080i60, each frame becomes two fields, for a perfect 1:2 ratio. The PsF signal itself looks identical to any other interlace SDI signal, and in fact there's no flag in the data stream to tell receiving equipment that it is PsF. So devices that support PsF either have to try to analyze the video to detect that PsF was used, or have an option to explicitly turn the decoding feature on.
Incompatibility with 3G SDI Level B may not always look like no picture at all. In the case of some monitors at the theatre I work at, they do notice the level B signal, but they interpret it incorrectly, making black look green/turqoise and white magenta. It also caused the picture to "vibrate" up and down at what I presume to be the framerate as if an interlaced signal was interpreted as progressive. I'm still in the weeds of understanding the theory behind why it looked exactly like that, but I wanted to share this in case anyone reading has a similar issue. A device expecting an RGB signal but getting a Y'C'bC'r signal and interpreting it as RGB can look very similar (green and magenta picture), so I thought I needed to adjust the monitors settings, but upon finding no such setting, I decided to get to work on at least achieving the other thing I set out to do, which is using the Blackmagic Converter Control software to change the HDMI to SDI converter I used to level B. I was quite happily surprised when this fixed the glaring color issue as well.
So when you convert SDI to USB 3 is there any loss in quality? What’s the best way to capture high quality s-video? S-video > SDI > USB 3? Very noisy old analog video needs a higher bitrate than a digital 8 camera (DV) can handle. How efficient is the codec used for SDI signals compared to, h.264? The DV codec I know is much less efficient than h.264 so 25mbps using DV is much lower quality than 25mbps h.264.
SDI -> USB 2.0 is usually compressed using mjpeg or h264. SDI -> USB 3.1 is either same as above or it car be raw data, uncompressed. s-video is not high res/frame rate so lots of lower rate equipment will be better than s-video - s-video can be digitised and sent over SD-SDI or just SDI. (for clarity SD-SDI -> HD-SDI -> 3G-SDI -> 6G-SDI -> 12G-SDI -> 24G-SDI is the order where each is roughly double the bandwidth of the previous) you can get s-video to USB2.0 adaptors if you need to do this. SDI does not normally use a CODEC as it's not 'compressed', other than chroma subsampling. Not h.264. DV is a storage format and therefore compression makes sense, SDI is a transmission format and therefore keeping it low latency is more important generally. It's worth noting that ASI is a multiple channel streaming format often used over SDI infrastructure. this is compressed but not used in the production until the last output stages usually.
Hey Doug. Could you pls clarify what do you mean at about 9 min in when you say that if shooting in 1080i or 1080p@30 there is no compatibility issues? Like in fiber converters or in general all equipment? Thanks in advance.
1080i and 1080p29.97 are both 1.5G signals. They both have the same 1.5 Gb/sec data rate. Both are considered HD-SDI. The whole Level A/B thing doesn’t come into play with HD-SDI that you get with 3G-SDI.
Probably not. It would require a pretty heavy cable. And even at 100M you're really at the maximum limit for SDI over copper. Most people needing to send signals that far use fiber.
Thanks I learned a lot but still have question lol on new red komodo I heard have sdi 6g can contect. It to 3g montier sdi 1080p or I need conversation?
Hello, great information by the way. I am checking out TH-cam videos in hopes of troubleshooting my rig. I have a Canon XC-10, so I send the mini-hdmi output of the XC-10 to a Convergent Designs Apollo external recorder. I am trying to use “titan” with the Apollo, which essentially takes one 4K signal and splits it up into 3 different 1080p signals. They can be live switched and set to different magnification amounts etc, and all recorded onto one SSD, essentially providing an affordable solution which is similar to a multi-camera setup. In order to do this though I need one 4K signal and I do not like using the mini hdmi cable from the canon xc10 to the external recorder because the hdmi jack on the camera is sensitive and I feel like when I use a “BMD hdmi to sdi converter”, there is less of a chance that I have problems with the mini- hdmi cable. So I got it all setup and it worked beautifully, or so I thought- I noticed that I still was not getting a 4K signal because my external recorder wasn’t displaying the 3 1080p feeds that were supposed to be present had a 4K signal been coming out of the “BMD hdmi to sdi converter”. I can toggle between 1080 and 4K on the camera, so I then noticed that everything works fine on 1080, (except it just displays one camera feed on my external recorder because of no 4K signal) So then as soon as I would switch my camera to “4K” mode, the display on the external recorder would go totally blank. The audio which was working on 1080 would also disappear. I have checked that the box is set to “force ultra hd”, but it still seems that the BMD box is unable to convert my cameras 4K signal to SDI... I believe I was attempting to use “30FPS”. I am using just one cable. So I was trying to learn the differences of 3g vs 6g etc and then I was going to try and find out a little more info on my equipment because I’m not sure if “type a” vs “type b” is able to be used on the camera and recorder, and seeing if I can find any other info to confirm that I am using the right equipment or if the problem is elsewhere. I was also thinking of trying to downgrade the firmware of the blackmagic converter box because it seems that another TH-camr has success doing so, but his problem was that the camera feed wouldn’t display on an external and he had a canon 5D- but same make of camera so I was hoping that might work- I am going to try a few more things in hopes of getting a 4K signal out of the BMD hdmi> sdi converter. Any tips or recommendations would of course be appreciated. Thanks for your well-explained videos (also watched the sdi-hdmi update video) Cheers, Nick
My software has drop down of the following output formats : PAL NTSC 240p 60 576p 25 600p 60 768p 60 after this one more drop down to select: SDI Composite HDMI Optical SDI Component Now which combination I have to choose for SD SDI ? Thanks in advance!!
For somebody just starting out now, do you suggest leaning towards 12G SDI gear or 3G SDI gear? I notice that there are not many affordable video options that can output 4K30 let alone 4K60. Even $5K cameras only have 3G SDI output. They can record 4K30/60 but cant output it. Which I find odd.
Get what fits your budget. Even though 4K is becoming more popular, HD is still very relevant today, especially for live streaming. Almost nobody is streaming in 4K, and that isn't changing very quickly. And the prices on the 4K gear will continue to fall, and you can upgrade later as there starts to be a demand for it. When I started building out my current video production setup five years ago, I started with mostly HD equipment and have upgraded components one at a time since then. I still have a bunch of gear that is HD-only. And none of my clients have ever asked for 4K, so we still shoot almost all events in HD.
Can I extend a let's say 10 meters/30 feet SDI cable with another 10m/30ft SDI cable to get 20 meters if needed? Would it work with just a simple female to female BNC connector?
@@djp_video Thank you for your answer. I got a longer question, maybe this would be for a future video for you: I'm looking into buying SDI, hopefully future proof. For 12G, how long can I run the coax cables before I'll have to go over to fiber? Do I get the same type of Belden cables as you've linked to for 3G, or do I need to get something else? What about the BCN-connectors? Do they need to be different in quality, compared to the 3G BCN connectors? And if I would need to do longer SDI runs for 12G, how does the conversion between coax and fiber look like? Are there other options than Blackmagics fiber converter that you would recommend? Hehe, sorry for the large chunk of questions. As I said, maybe this should be called a video request. :)
@@christofferahlback The equipment involved can make a huge difference, so any advice I give needs to be taken with that in mind. Using the Belden 1505A I mentioned in the video, I don't think I'd try to push 12G-SDI much past 20 meters -- it just isn't designed for it. You can step up to 1694A for some additional distance, but it won't get you out to 100 meters. If you know you'll be going to 12G-SDI, you might consider getting cable designed for it from the start. From Belden, that's the 4505 and 4694 series. From Canare, look at L-8CUHD, L-5.5CUHD, or L-3.3UHD (best option listed first) with their corresponding BCP-D8UHD/BCP-D55UHD/BCP-D33UHD connectors. The BNC connectors absolutely do make a big difference. Go with Canare or Neutrik models specifically designed for whatever cable you purchase and you'll be in good shape. There are fiber converters available from other companies, but the prices jump big-time. AJA's are relatively affordable, but pretty much every other brand worth considering gets really expensive really quickly. With 12G-SDI and even the best quality cables, I wouldn't use copper cables for anything over about 100 meters.
@@djp_video Thank you so much for your answer, Doug! With that in mind, if I understand you correctly, I could use the "normal" 3G SDI Coax cables like Belden 1505A with corresponding connectors for 12G up to around 20 meters before I need better cables or fiber?
Yes, you can get away with the 1505A/1694A for 12G up to around 20 meters. That varies somewhat with the equipment you're using and how noisy (RF) the environment is.
BNC is the connector, the cable is referred to as coax, and SDI is the signal type. Time code is usually an audio signal that would generally use balance audio cables like XLR, but some implementations do use a BNC connector. Audio frequencies are so low compared to video that a video cable would work just fine, even if it wasn’t specifically designed for it.
Thanks for great explanations. But SDI has reached its technological limit. Broadcast facilities are switching to video over IP by the means of SMPTE 2110 standards. What are your thoughts about i?
It definitely holds promise. It still feels like it is a way off for most facilities though. Having been at NAB pretty much every year for quite a while now, I've seen it emerging, but it doesn't seem to be catching on as quickly as I would have thought a few years ago. I wouldn't go so far as to say that SDI has reached its limit. It may be getting more and more difficult to transport higher and higher data rates over copper cable, but we're barely scratching the surface of what optical fiber can do, and SDI over fiber is quite common. The beauty of SDI is that it is simple. IP adds another layer of complexity on top of it that in many cases doesn't provide enough benefit to make a switch. Ultimately time may tell, but I'm just not seeing a mass migration from SDI to IP in process today. If it does take over, it's going to be a long time coming.
Good points. I see OB trucks switching to video over IP basically for the added flexibility and huge weight savings. I've have heard that the BBC is also switching to IP (slowly though). The audio guys have successfully switched to IP and the workflows now are quite established and reliable. Take Riedel as an example. As for video, what do u think of Riedel Mediornet, is it mature enough for "prime time"? As for the SDI limit, my point is that you need 4 SDI cables to transmit 4k signals. Fiber is expensive compared to CAT6 Ethernet cables and not very flexible, difficult to fuse cables, fixed network architecture... I'm not saying the video over IP is cheap as we really cannot use off-the-shelve IT equipment at all, at least not now. Maybe in a few years...
@@SportFlow Cat 6 ( 10G) can transmit 4k30 (6G) 50 meters (in a friendly enviorment), Cat 6A or Cat 7 can go 100 Meters. NO Cat X cable can transmit 4K60 (12G) which can be transmitted on ONE SDI cable or fiber. 8K60 Requies FOUR 12G signals.
@@jimmichaels5058 Thanks for your points. Another thing to take into consideration is that SDI is a common interface. If a machine has an SDI output it sure will be compatible with any other SDI input from any manufacturer. When dealing with IP-based facility, things get more complicated. Everything is not compatible with everything. Most of the time you have to marry one manufacturer (Riedel, Sony, Grassvalley...) and stick with it.
@@SportFlow "Everything is not compatible with everything." There's the rub. The manufacturers are greedy and until a universal standard is reached SDI will remain the majority interfacing format.
So... I know the sdi signal runs on coax, rg-59 75 Ohm or something, but I don't have that. My parents home for exsample, as well as a lot of other places, have rg-6. Can you still run a SDI 3g signal on rg-6? What limitations does rg-6 have over rg-59?
Hey, Joshua! I'll have to do a full video on this at some point. RG-59 and RG-6 are both 75-ohm cables, and SDI can be run over either one. RG-6 is generally better at handling higher frequencies, which actually makes it preferred for over RG-59 -- especially for longer runs or for higher bandwidth applications, but it does depend on the particular model of cable and the quality of the connectors on the ends. A lot of times the RG-6 that is installed in homes isn't terribly high quality, but it would likely work just fine for SDI, especially if good quality connectors are used. The most common coax that you want to avoid is RG-58, which is 50-ohm rather than the required 75-ohm. You'll typically find it used for radio applications (like HAM, for example).
Sometimes you can get away with cables designed for 3G-SDI for 6G or 12G for shorter runs. It really depends on the quality of the cable, connectors, and the transmitting and receiving equipment. For example, I'm able to use cables made from Belden 1505A, which is only certified for 3G, for 6G-SDI at 100 feet without issue. But ideally you would want cables certified for the flavor of SDI you're using.
What do you do with the extra SDI lengths that you dont need whilst its on the cable reel. EG, you have 50m SDI length but you only use 30m. Do you leave the other 20m on the reel or do you unreel it and leave it neet on the floor. Thanks mate.
@@joshuamars-downunderputtin3428 About the longest I use normally would be 150 feet. Anything longer and I just go straight to fiber. I roll my cables using the over/under method, and tie with Velcro straps.
If you're coiling by hand, the over/under method prevents twisting of the cable, which reduces long-term damage. It also keeps the cable from getting tangled and knotted. Reels also prevent twisting, but they take up a lot of space (which is at a premium in my trailer) and take longer to spool and unspool.
Wow. This video is bad. I tried watching hoping it would quickly explain the differences to make choices. Too much run on and irrelevant info for that. A graph with some images and a breakdown could have made this video way more valuable... as it is these 17 minutes are excruciating to sit through. Sorry man. Just frustrated.
good info! i'd encourage everyone to watch the whole thing but if you're in a rush...
1:03 What is SDI? / History Of SDI
5:57 3G Level B - Dual Link
7:14 3G Level A
10:58 Caveats to using HD-SDI for 1080@24/30
12:29 3G Level B - Dual Stream
13:32 6G and 12G
Hi Doug, if you see this these videos of yours are still very useful and much appreciated. Thanks.
That was a solid run through , very succinct . Much appreciated 👍
Excellent video Doug. Good refresher for me on A vs B standards
Great video Doug, I was always wondering about Level A & Level B SDI. Thanks for clearing that up. For anyone thinking of becoming a Patreon it is WELL worth your time, especially if you are in this kind of industry, or even just interested in it.
Excellent summary, Doug - I must admit that this is something i've found very useful :)
Great video. I work in corporate AV as a video engineer and this was the explanation I was looking for.
And now Doug will explain every technical detail about SDi that you never knew you needed to know... :D
Thanks for the succinct explanations. Easy to understand and very helpful.
Just found this channel great job on explaining the details.
Very well explained thanks. Could you do a video explaining “gen locking”, ref in, Black burst etc. I have a rough idea of what it’s all about but when do I need it? I have a BM television studio HD and a few BM studio cameras do I have to use gen locking? Thanks again!
I could do something theoretical. I don't really have the right gear to demonstrate it properly, though.
Doug Johnson Productions thanks anyway. There doesn’t seem to be a lot of info out there on the when and why. I just really want to know what I’m missing by NOT using it! Great work by the way, I always learn something from your vids.
The biggest difference you see without using genlocked cameras is longer delays from the camera to final switcher output. Without having synchronized sources the switcher has to delay all incoming video sources by up to a half a frame to make them all match. If you run in a genlocked environment that delay is eliminated.
Doug Johnson Productions OK I can understand that but is half a frame delay really that noticeable? Is the delay different for each camera and dependent on cable length or something? Thanks for the help, it’s much appreciated :)
That depends on several factors, most significantly the frame rate. (Cable length is not one of them.) If you're shooting, say, at 24 fps, any two cameras could be out of sync by as much as 1/24 of a second since they have no common source of synchronization. If you're dealing with a fast moving subject, or a source that requires precise synchronization with audio, that 1/24 of a second could be noticeable when switching between those cameras. And if you're projecting the video live that extra delay from having unsynced cameras might be the difference between the delay being perceptible vs. not.
Shooting at higher frame rates like 60 fps can help minimize the perceptible delay, since the maximum difference between the start of the frames of any two cameras would be 1/60 second instead of 1/24 second.
Thanks for the video, Doug. Great information.
You are the man!
Great Video! Thank you!
Another Great Video Doug !
Very informative, thank you.
Very useful, thanks !
Im a bit confused with SDI existing in the late 80's. However, I don't recall seeing it on any gear up until the late 2000's. At the time even tv stations I was working at, just used analogue SD over BNC connectors. Was it just a slow implementation as the rollout of HDTV took a long time?
Pretty much. In a lot of situations there wasn't a huge pratical benefit to switching over from analog to digital, so existing analog systems just kept getting used. SDI would have given a cleaner signal, but not as big of a jump as going from SD to HD.
Well explaned, thanks!
Great video! Thanks! :D
SDI cable length plays a big role in transferring data as well.
"combined into a single signal". Now that's a mouthful!
Great Video - thank you! Is the Canare TS100U Coaxial Cable Stripper good also for the Belden 1694F Digital Video Coaxial Cable? THANK YOU
You certainly can. It isn't necessarily setup with a preset for 1694F, but you can adjust the blades if you aren't getting a good strip.
How do you tell the difference or what whether equipment is level A or level B?
Is it stated somewhere, or printed on a tag, or can you test?
Sometimes you'll find it in product documentation. But not always.
Blackmagic Design does everything using Level B. Sony camcorders also use Level B. Professional ENG cameras often use Level A. And most other manufacturers tend to use Level A.
Newer Blackmagic Design equipment (from about the last 5 years or so) can accept either Level A or B, and often lets you choose which of the two it will output.
Hope you can help. I was in video in the analog days. Now watching your channel I am looking to convert from a NTSC Hitachi C1 video camera , to SDI. I bought a AJA D10AD and the Decimator MD-HX. The dip switches on the AJA and the menu on the MD-HX are confusing. Wanting to view the camera video through HDMI on Samsung television. There are no videos that walk through this set up.
From what I can tell the Hitachi C-1 doesn't have an SDI output -- just composite video.
Your AJA D10AD should be able to convert the composite video from the C-1 to SDI. And then the Decimator should be able to convert the SDI to HDMI.
I don't have any experience with the AJA converter. On the Decimator, start in the Control menu, press the Enter button, then use the left/right arrows until you get to the HDMI Source screen. Press Enter repeatedly until SDI is selected.
Alternatively, many televisions support composite video. Check your manual for your television to see if it does. Depending on the model it may require an RCA-to-1/8" plug adapter, which likely would have come with the television if it does support it. If your TV can accept composite video, all you'd need would be a simple cable to go from the video output of the C-1 camera to the composite input on your television; the other adapters wouldn't be required unless you have a specific need to convert to SDI or HDMI.
hi i im using SDI cable to livestreamg and i using 50 feet long SDI and i have issues went i transmiting the screen go on and off and i have been with that problem since i get the camara including the cable please any advice will appreciate thanks
That sounds a lot like a bad cable. Is the cable you’re using 75-ohm, like an RG-59 or RG-6? Is it a high quality cable with good shielding? Is the cable and it’s connectors free from damage?
One way to see if it is a cable issue is to connect the devices with a short cable to see if you still have the dropouts. If they go away, you need to replace your cable. If it still has dropout issues, one of the devices has a problem.
Thank you for this
Good movie. Thank you .
Very interesting video... could this be the reason why my ATEM Tv studio HD did not recognise a pxm x400 1080p25 signal?
1080p25 falls within the HD-SDI spec, so 3G shouldn't be coming into play. Make sure your camera and switcher are set to the same video format and frame rate. And make sure the camera is actually outputting 25p, not 50i.
You mentioned Sony only does Level B, but that is not entirely accurate. If you use one of our Studio Cameras capable of 1080p, like the HDC1700 or better with 3G activated, then you can choose Level A or Level B when in the 3G format. To select A or B when in the 4K mode, you would select this from the 4K output menu or on the RCP.
I thought I had qualified my statement that I was referring to their camcorder style cameras.
Thanks Doug. Very well explained. Another question for you, what is the differentce between progresive and Psf signals and if there is a difference in quality between the two? Thanks
PsF (Progressive Segmented Frame) is a technique of wrapping what starts out as a progressive video signal into an interlaced output signal. It isn't a discrete signal type of its own. The format of the output looks identical to any interlaced signal.
Using PsF you could, for example, shoot at 24 or 30 fps, and output that video over 1080i. The "segmented frame" portion of the name means it splits individual frames across multiple fields of the interlace video. So a 30fps signal could be converted to 60i by simply splitting the odd and even lines into separate fields in the output video. In the distinct case of 24fps being wrapped into 1080i60, something called 3:2 pulldown can be used, where frame 1 of the original video is stored in 3 fields of the output interlaced video (each field containing half of the picture vertically), frame 2 is stored in the next 2 fields, then alternating back and forth thereafter. Video devices which are equipped to process PsF can reverse the process and reassemble the original 2 frames from the 5 fields, without any loss in quality compared to the original. For 30 fps material wrapped in 1080i60, each frame becomes two fields, for a perfect 1:2 ratio.
The PsF signal itself looks identical to any other interlace SDI signal, and in fact there's no flag in the data stream to tell receiving equipment that it is PsF. So devices that support PsF either have to try to analyze the video to detect that PsF was used, or have an option to explicitly turn the decoding feature on.
So whether SDI is level A or B is not up to the cable but the device its connected to right?
Correct. The device generating the video determines which type is output. And the receiving device has to be compatible.
Incompatibility with 3G SDI Level B may not always look like no picture at all. In the case of some monitors at the theatre I work at, they do notice the level B signal, but they interpret it incorrectly, making black look green/turqoise and white magenta. It also caused the picture to "vibrate" up and down at what I presume to be the framerate as if an interlaced signal was interpreted as progressive. I'm still in the weeds of understanding the theory behind why it looked exactly like that, but I wanted to share this in case anyone reading has a similar issue. A device expecting an RGB signal but getting a Y'C'bC'r signal and interpreting it as RGB can look very similar (green and magenta picture), so I thought I needed to adjust the monitors settings, but upon finding no such setting, I decided to get to work on at least achieving the other thing I set out to do, which is using the Blackmagic Converter Control software to change the HDMI to SDI converter I used to level B. I was quite happily surprised when this fixed the glaring color issue as well.
It depends entirely on the device. Seeing no signal at all is the most common result of connecting B to a device expecting A.
So when you convert SDI to USB 3 is there any loss in quality? What’s the best way to capture high quality s-video? S-video > SDI > USB 3? Very noisy old analog video needs a higher bitrate than a digital 8 camera (DV) can handle. How efficient is the codec used for SDI signals compared to, h.264? The DV codec I know is much less efficient than h.264 so 25mbps using DV is much lower quality than 25mbps h.264.
SDI -> USB 2.0 is usually compressed using mjpeg or h264.
SDI -> USB 3.1 is either same as above or it car be raw data, uncompressed.
s-video is not high res/frame rate so lots of lower rate equipment will be better than s-video - s-video can be digitised and sent over SD-SDI or just SDI. (for clarity SD-SDI -> HD-SDI -> 3G-SDI -> 6G-SDI -> 12G-SDI -> 24G-SDI is the order where each is roughly double the bandwidth of the previous) you can get s-video to USB2.0 adaptors if you need to do this.
SDI does not normally use a CODEC as it's not 'compressed', other than chroma subsampling. Not h.264. DV is a storage format and therefore compression makes sense, SDI is a transmission format and therefore keeping it low latency is more important generally.
It's worth noting that ASI is a multiple channel streaming format often used over SDI infrastructure. this is compressed but not used in the production until the last output stages usually.
Hey Doug. Could you pls clarify what do you mean at about 9 min in when you say that if shooting in 1080i or 1080p@30 there is no compatibility issues? Like in fiber converters or in general all equipment? Thanks in advance.
1080i and 1080p29.97 are both 1.5G signals. They both have the same 1.5 Gb/sec data rate. Both are considered HD-SDI. The whole Level A/B thing doesn’t come into play with HD-SDI that you get with 3G-SDI.
Is 12G SDI over Coax feasible with >100 m and a flexible easy to deploy coax cable in mobile situations?
Probably not. It would require a pretty heavy cable. And even at 100M you're really at the maximum limit for SDI over copper. Most people needing to send signals that far use fiber.
Did you ever get around to making that video about 4:2:2/4:4:4? I can't find it.
Not yet. It's one of the next on the list, though.
Thanks I learned a lot but still have question lol on new red komodo I heard have sdi 6g can contect. It to 3g montier sdi 1080p or I need conversation?
If you're outputting a 1080p or lower signal your 1080p monitor will work.
Hello, great information by the way. I am checking out TH-cam videos in hopes of troubleshooting my rig.
I have a Canon XC-10, so I send the mini-hdmi output of the XC-10 to a Convergent Designs Apollo external recorder. I am trying to use “titan” with the Apollo, which essentially takes one 4K signal and splits it up into 3 different 1080p signals. They can be live switched and set to different magnification amounts etc, and all recorded onto one SSD, essentially providing an affordable solution which is similar to a multi-camera setup.
In order to do this though I need one 4K signal and I do not like using the mini hdmi cable from the canon xc10 to the external recorder because the hdmi jack on the camera is sensitive and I feel like when I use a “BMD hdmi to sdi converter”, there is less of a chance that I have problems with the mini- hdmi cable.
So I got it all setup and it worked beautifully, or so I thought- I noticed that I still was not getting a 4K signal because my external recorder wasn’t displaying the 3 1080p feeds that were supposed to be present had a 4K signal been coming out of the “BMD hdmi to sdi converter”.
I can toggle between 1080 and 4K on the camera, so I then noticed that everything works fine on 1080, (except it just displays one camera feed on my external recorder because of no 4K signal)
So then as soon as I would switch my camera to “4K” mode, the display on the external recorder would go totally blank. The audio which was working on 1080 would also disappear.
I have checked that the box is set to “force ultra hd”, but it still seems that the BMD box is unable to convert my cameras 4K signal to SDI... I believe I was attempting to use “30FPS”. I am using just one cable.
So I was trying to learn the differences of 3g vs 6g etc and then I was going to try and find out a little more info on my equipment because I’m not sure if “type a” vs “type b” is able to be used on the camera and recorder, and seeing if I can find any other info to confirm that I am using the right equipment or if the problem is elsewhere.
I was also thinking of trying to downgrade the firmware of the blackmagic converter box because it seems that another TH-camr has success doing so, but his problem was that the camera feed wouldn’t display on an external and he had a canon 5D- but same make of camera so I was hoping that might work-
I am going to try a few more things in hopes of getting a 4K signal out of the BMD hdmi> sdi converter. Any tips or recommendations would of course be appreciated. Thanks for your well-explained videos (also watched the sdi-hdmi update video)
Cheers,
Nick
My software has drop down of the following output formats :
PAL
NTSC
240p 60
576p 25
600p 60
768p 60
after this one more drop down to select:
SDI
Composite
HDMI
Optical SDI
Component
Now which combination I have to choose for SD SDI ?
Thanks in advance!!
I'd like to answer your question, but I need a little more context... what is it you're doing?
It’s a kind of playout software, I’m trying to output a SD-SDI signal
Great video, do you know what frequencies are used for 3G-SDI (12G?) signal?
It's just under 3 GHz.
For somebody just starting out now, do you suggest leaning towards 12G SDI gear or 3G SDI gear? I notice that there are not many affordable video options that can output 4K30 let alone 4K60. Even $5K cameras only have 3G SDI output. They can record 4K30/60 but cant output it. Which I find odd.
Get what fits your budget. Even though 4K is becoming more popular, HD is still very relevant today, especially for live streaming. Almost nobody is streaming in 4K, and that isn't changing very quickly. And the prices on the 4K gear will continue to fall, and you can upgrade later as there starts to be a demand for it.
When I started building out my current video production setup five years ago, I started with mostly HD equipment and have upgraded components one at a time since then. I still have a bunch of gear that is HD-only. And none of my clients have ever asked for 4K, so we still shoot almost all events in HD.
Can I extend a let's say 10 meters/30 feet SDI cable with another 10m/30ft SDI cable to get 20 meters if needed? Would it work with just a simple female to female BNC connector?
Yes. There is a bit of signal loss with each connection, so I'd be careful doing this with longer cables.
@@djp_video Thank you for your answer. I got a longer question, maybe this would be for a future video for you: I'm looking into buying SDI, hopefully future proof. For 12G, how long can I run the coax cables before I'll have to go over to fiber? Do I get the same type of Belden cables as you've linked to for 3G, or do I need to get something else? What about the BCN-connectors? Do they need to be different in quality, compared to the 3G BCN connectors? And if I would need to do longer SDI runs for 12G, how does the conversion between coax and fiber look like? Are there other options than Blackmagics fiber converter that you would recommend? Hehe, sorry for the large chunk of questions. As I said, maybe this should be called a video request. :)
@@christofferahlback The equipment involved can make a huge difference, so any advice I give needs to be taken with that in mind.
Using the Belden 1505A I mentioned in the video, I don't think I'd try to push 12G-SDI much past 20 meters -- it just isn't designed for it. You can step up to 1694A for some additional distance, but it won't get you out to 100 meters. If you know you'll be going to 12G-SDI, you might consider getting cable designed for it from the start. From Belden, that's the 4505 and 4694 series. From Canare, look at L-8CUHD, L-5.5CUHD, or L-3.3UHD (best option listed first) with their corresponding BCP-D8UHD/BCP-D55UHD/BCP-D33UHD connectors.
The BNC connectors absolutely do make a big difference. Go with Canare or Neutrik models specifically designed for whatever cable you purchase and you'll be in good shape.
There are fiber converters available from other companies, but the prices jump big-time. AJA's are relatively affordable, but pretty much every other brand worth considering gets really expensive really quickly. With 12G-SDI and even the best quality cables, I wouldn't use copper cables for anything over about 100 meters.
@@djp_video Thank you so much for your answer, Doug! With that in mind, if I understand you correctly, I could use the "normal" 3G SDI Coax cables like Belden 1505A with corresponding connectors for 12G up to around 20 meters before I need better cables or fiber?
Yes, you can get away with the 1505A/1694A for 12G up to around 20 meters. That varies somewhat with the equipment you're using and how noisy (RF) the environment is.
Is it correct to say BNC is just the connector. It is for SDI cable? Can I use SDI cable for timecode siync? Thank you
BNC is the connector, the cable is referred to as coax, and SDI is the signal type.
Time code is usually an audio signal that would generally use balance audio cables like XLR, but some implementations do use a BNC connector. Audio frequencies are so low compared to video that a video cable would work just fine, even if it wasn’t specifically designed for it.
@@djp_video you are awesome. Really appreciate it
Thanks for great explanations. But SDI has reached its technological limit. Broadcast facilities are switching to video over IP by the means of SMPTE 2110 standards. What are your thoughts about i?
It definitely holds promise. It still feels like it is a way off for most facilities though. Having been at NAB pretty much every year for quite a while now, I've seen it emerging, but it doesn't seem to be catching on as quickly as I would have thought a few years ago.
I wouldn't go so far as to say that SDI has reached its limit. It may be getting more and more difficult to transport higher and higher data rates over copper cable, but we're barely scratching the surface of what optical fiber can do, and SDI over fiber is quite common. The beauty of SDI is that it is simple. IP adds another layer of complexity on top of it that in many cases doesn't provide enough benefit to make a switch. Ultimately time may tell, but I'm just not seeing a mass migration from SDI to IP in process today. If it does take over, it's going to be a long time coming.
Good points. I see OB trucks switching to video over IP basically for the added flexibility and huge weight savings. I've have heard that the BBC is also switching to IP (slowly though). The audio guys have successfully switched to IP and the workflows now are quite established and reliable. Take Riedel as an example. As for video, what do u think of Riedel Mediornet, is it mature enough for "prime time"? As for the SDI limit, my point is that you need 4 SDI cables to transmit 4k signals. Fiber is expensive compared to CAT6 Ethernet cables and not very flexible, difficult to fuse cables, fixed network architecture... I'm not saying the video over IP is cheap as we really cannot use off-the-shelve IT equipment at all, at least not now. Maybe in a few years...
@@SportFlow Cat 6 ( 10G) can transmit 4k30 (6G) 50 meters (in a friendly enviorment), Cat 6A or Cat 7 can go 100 Meters. NO Cat X cable can transmit 4K60 (12G) which can be transmitted on ONE SDI cable or fiber. 8K60 Requies FOUR 12G signals.
@@jimmichaels5058 Thanks for your points. Another thing to take into consideration is that SDI is a common interface. If a machine has an SDI output it sure will be compatible with any other SDI input from any manufacturer. When dealing with IP-based facility, things get more complicated. Everything is not compatible with everything. Most of the time you have to marry one manufacturer (Riedel, Sony, Grassvalley...) and stick with it.
@@SportFlow "Everything is not compatible with everything." There's the rub. The manufacturers are greedy and until a universal standard is reached SDI will remain the majority interfacing format.
So... I know the sdi signal runs on coax, rg-59 75 Ohm or something, but I don't have that. My parents home for exsample, as well as a lot of other places, have rg-6. Can you still run a SDI 3g signal on rg-6? What limitations does rg-6 have over rg-59?
Hey, Joshua!
I'll have to do a full video on this at some point. RG-59 and RG-6 are both 75-ohm cables, and SDI can be run over either one. RG-6 is generally better at handling higher frequencies, which actually makes it preferred for over RG-59 -- especially for longer runs or for higher bandwidth applications, but it does depend on the particular model of cable and the quality of the connectors on the ends. A lot of times the RG-6 that is installed in homes isn't terribly high quality, but it would likely work just fine for SDI, especially if good quality connectors are used.
The most common coax that you want to avoid is RG-58, which is 50-ohm rather than the required 75-ohm. You'll typically find it used for radio applications (like HAM, for example).
Are the BNC cables able to be used with 3g 6g and 12g or do you need cables made for those standards?
Sometimes you can get away with cables designed for 3G-SDI for 6G or 12G for shorter runs. It really depends on the quality of the cable, connectors, and the transmitting and receiving equipment. For example, I'm able to use cables made from Belden 1505A, which is only certified for 3G, for 6G-SDI at 100 feet without issue. But ideally you would want cables certified for the flavor of SDI you're using.
What do you do with the extra SDI lengths that you dont need whilst its on the cable reel. EG, you have 50m SDI length but you only use 30m. Do you leave the other 20m on the reel or do you unreel it and leave it neet on the floor. Thanks mate.
I don't use reels for my SDI cables. Usually I just leave the extra length coiled up, laying on the floor.
Thanks for the reply Doug, what is the longest length SDI you use and how do you roll / coil yours?
@@joshuamars-downunderputtin3428 About the longest I use normally would be 150 feet. Anything longer and I just go straight to fiber.
I roll my cables using the over/under method, and tie with Velcro straps.
Thanks for the reply. What is the reasoning for that. Does it look after the cable better. Do you find it easier to lay ( not as much memory coils. )
If you're coiling by hand, the over/under method prevents twisting of the cable, which reduces long-term damage. It also keeps the cable from getting tangled and knotted. Reels also prevent twisting, but they take up a lot of space (which is at a premium in my trailer) and take longer to spool and unspool.
The legendary Sony PVM-A170.
Absolutely love mine!
dual strem is mostly usded for 3d stereoscopic camera transfer.
Wow. This video is bad. I tried watching hoping it would quickly explain the differences to make choices. Too much run on and irrelevant info for that. A graph with some images and a breakdown could have made this video way more valuable... as it is these 17 minutes are excruciating to sit through. Sorry man. Just frustrated.
Lol