Linux Audio Explained (ALSA vs PulseAudio vs JACK vs Pipewire Explained)
ฝัง
- เผยแพร่เมื่อ 27 มิ.ย. 2024
- In this video, I explain how audio and sound works on Linux based comptuers and systems.
More specifically, I go over the point of sound hardware, kernel drivers such as OSS and ALSA and userspace sound servers such as PulseAudio, Jack and Pipewire.
Along the way, I discuss the advantages and drawbacks of the current implementations, as well as why one implementation is often favored over another.
Finally, I discuss the latest-and-greatest sound server, Pipewire, what it means, and how you can benefit from the improvements.
This video is a bit rambly at times, so please stick with me, and I hope you learn something throughout and feed your curiosity.
Please feel free to use the timestamps below to skip between sections!
Links are shortened to fit 5000 characters.
Full description at wiki.tonytascioglu.com/doku.p...
Timestamps
Introduction
00:00 - Introduction
The Hardware
00:18 - Basic Hardware, Inputs and Outputs
00:36 - Sound Cards (and what they do)
01:01 - Digital Audio, PCM and extra hardware
Kernel Drivers
01:29 - Kernel Drivers! (How to interact with hardware)
01:53 - OSS (Open Sound System)
02:12 - ALSA (Advanced Linux Sound Architecture)
02:46 - ALSA Limitations - hardware mixing/multiplexing
Userspace Sound Servers
03:54 - Pulseaudio (and sound servers)
04:25 - Benefits of PA - mixing and resampling
07:26 - Drawbacks of PA (and JACK introduction)
08:13 - JACK and its benefits
09:57 - Comparison with PA and other software
Pipewire (and ramble)
11:12 - Pipewire (and its benefits)
14:05 - Future of Pipewire
15:17 - Note on Bluetooth (rant)
note: mostly fixed!
17:52 - Conclusion
Links
- Sound Cards
bit.ly/2UvGBgE
- Check ALSA compatibility of a sound card
bit.ly/3xWEz72
- DAC and ADC
bit.ly/3j0SQLG
bit.ly/3y2S0Cj
- Nyquist Shannon sampling theorem
I didn't get to it in this video, but it explains why 44.1 and 48 kHz are perfectly fine.
More specifically, how we can perfectly reconstruct analog waves provided no aliasing and they are below the nyquist frequency.
bit.ly/3subi2s
- Chris Montgomery Videos
I found these super helpful to understand digital audio and video fundamentals.
Discusses PCM and more, and also the nyquist stuff from above in video 2.
bit.ly/3z38VWX
bit.ly/3AVppkf
bit.ly/3sx0Siw
Also see Chris' blog while you're at it, some interesting reads:
bit.ly/3k8HNiR
- Kernel Driver Architecture
I found this a simple overview when researching
bit.ly/3AWt7dv
- OSS
bit.ly/2W13Q37
bit.ly/380v4t4
- ALSA
bit.ly/2UBKAbI
The sound card compatibility list is above. The Gentoo and Arch wiki entries are useful.
bit.ly/2XCca9L
bit.ly/3sxsKmu
- Sound card multiplexing
bit.ly/380v8ZQ
bit.ly/3gfFeKA
Use a sound server. Don't do this manually bit.ly/384QKUB
- Pulseaudio
Homepage: bit.ly/3z9Fjas
User docs: bit.ly/3CUQHsO
Git: bit.ly/3meKF0k
As usual, the arch page and examples are good:
bit.ly/3z4lMbk
bit.ly/3D33cCH
- Jack
Homepage: bit.ly/3mfGqld
Jack1 git: bit.ly/3yYKr0O
Jack2 git: bit.ly/3miJsoE
Wiki (and tools using Jack) bit.ly/3mhBGeF
Archwiki: bit.ly/3y0LbRN
- Pipewire
Hoempage: bit.ly/3B0RPcP
Neat demo and features, and other benefits discussed on hackaday here: bit.ly/3kceL1I
Archwiki as always: bit.ly/3j0Ypd2
Wiki - contains useful config parameters for pulse and jack: bit.ly/3ghHPUi
Git: bit.ly/3j22q0J
- Firewire
If you have one, your best bet is bit.ly/3gdeyKH
Notes (no : to avoid YT linking it)
0040 - When I say sound card, most computers have one build in these days, eg: onboard audio. Physical discrete cards are mostly a thing of the past.
0250 - Sound card multiplexing also often called hardware mixing.
1240 - There is also a "Pro Audio" mode for sound cards that splits all the channels
1705 - Most of these disconnection issues are now fixed as of the time of publishing!
I'll add more notes as I remember when rewatching this.
Please note that due to classes and school and coop, the filming/editing/uploads of my videos are very delayed, and might not be the most sensitive.
Thanks to
Randy MacLeod (and the rest of the Wind River Linux team). I know you had asked me about Pipewire at some point, and I already had this video in the works, so hopefully you find it useful :)
Misc
Watch this video on Peertube: bit.ly/3D5i57o
Copyright 2021 - Tony Tascioglu
I'm making this freely available under a CC-BY-SA-NC.
Email: tonytash@pm.me
I hope you enjoyed the video and learned something!
#Linux #Audio #Pipewire
Corrections
- MIDI stands for Musical Instrument Digital Interface - วิทยาศาสตร์และเทคโนโลยี
Pipewire started life as a way to handle the gaps left in Wayland for stream capturing with v4l2 and dma-buff, zero copy screen sharing, audio/video sync, etc. They ended up recreating the pulseaudio server as a plugin and reimplementing the JACK interface with a focus on latency. It really is a wonderful project.
Great info! Thanks!!! Have been using Linux for over 15 years, never gave a second thought to how audio works on Linux. After watching this, I uninstalled PulseAudio and installed PipeWire. I have a large living room, and used to get "crackling" when using my Bluetooth headsets. This is no longer the case with PipeWire!! Have only had it installed for an hour though, so will see how it goes.
How are you liking PipeWire so far?
@@Lambda_Ovine I'm loving it! I'm not really an "audiophile", but it does sound better on my setup (no more intermittent crackling). I've converted my laptops over to Pipewire too :) Does everything I need to do, but my needs are very straight forward and simple (i.e. just need audio through Bluetooth speaker). Actually, I WFH, so I video conference too.
Glad to hear that Pipewire bluetooth is working well!
Actually, I noticed the crackle/stutter under PulseAudio on my laptop as wel last yearl, I had tried so many things with Pusleaudio such as forcing SBC (thinking it would use less bandwidth or something), messing with the server delay and buffer times (thinking it was a buffer underrun or something), even turning off WiFi in case both the 2.4 GHz signals are interfering... I guess this did disappear when I switched over and never noticed, neat!
This is exactly what I was looking for- not a tutorial but an explanation of how everything fits together. You rock!!
Thanks! Glad you found it useful!
Thanks for doing such a nice rundown. I have been using PipeWire for a good few months now without any major issues. I had major issues about half a year ago (I know this video was released even before that time). In my experience so far, BT headphones work better with PipeWire than they did with PuldeAudio, though I don't use them that much. An amazing thing is that using PipeWire I can record audio from my BT headset right into Ardour, like any regular audio input. Plus I can work on my music using them in playback only profile. It's pretty amazing.
Yeah, I think the stability and support for Pipewire has greatly improved in the past year. As for recording audio from Bluetooth, make sure you check which sound profiles you're using, since some definitely sound better then others with Bluetooth (SBC-XQ vs SBC for playback for example)!
@@TonyTascioglu Ah, interesting! Yes, the quality in duplex over Bluetooth is usually pretty bad. Having an option to improve that would be great.
YOOOO IT'S UNFA?? HOW IS THIS NOT PINNED??
Really excellent explanation and exactly the kind of patient, thorough guide through linux audio that I never knew I wanted. I recently had some trouble switching my audio output from the hdmi port on my video card to a usb out connected to my headphone amplifier and suddenly I needed to learn about how sound worked.
You seem really knowledgeable and did a great job explaining the full stack of technology powering audio. I would absolutely tune in for more videos like this (even if they take a year to put together :-)).
Thank you!
Hey, thanks a lot for the kind words, glad you enjoyed it!
`pavucontrol` is probably the easiest DE-agnostic way to easily switch inputs and outputs in general or on a per-program basis provided you're using PulseAudio or PipeWire.
Thank you for keeping this up over the years. It's people like you and content like this that made TH-cam the beautiful place it once was and make me reminisce. Thanks for making me feel nostalgic AND giving me the high level overview I was looking for. Keep on tinkering my friend.
This video helped me grasp things that I wouldn't have known how to search or troubleshoot. I've been able to solve a problem on my PC thanks to you! Appreciate the info 👍
An update to this video, taking into consideration the recent audio technology updates (using ALSA and PIPE WIRE only), would be very welcome. Tank you for this video anyway.
I've researched a lot about this topic and this was the best explanation I saw on how sound works on linux, thanks a lot for this video.
Glad it helped!
I'm a total noob when it comes to linux however If I understand this correctly: Pipewire has the potential to give us pro audio users the ability to route multiple sources to the same and/or different outputs simultaneously. If this is the case, this would be game changing for those looking for advanced audio routing solutions. It would also be much more affordable than using Dante where you would require something like a
CTP DIO88 Analogue to Dante Converter upwards of ($1000/£1000 give or take) to convert your devices and send them where you need to.
great explanation complete from input to output
You are an amazing teacher! It is extremely rare to have capacity for knowledge and a great personality. If only grade school was full of interesting people, everything might be different. Thanks for sharing this knowledge strangely two months before I needed it.
Really appreciate you putting this together. This is a great overview / intro to understanding the ecosystem
Thanks for the kind words! Glad it is helpful!
This was a really great explainer. I never got how ALSA worked until now. I'm still unsure about Pipewire since it seems so buggy, but hopefully it will be stable enough to try on the next Mint LTS. After all those Ubuntu users test it for us, lol.
Ah yes the Arch/Fedora/SuSe Leap -> Ubuntu/Manjaro -> Debian/CentOS/Mint chain of software propagation...
Jokes aside, thanks for the kind words and glad you found it helpful!
Wow! You covered a lot of ground in one video, Tony--my head nearly exploded! Thanks for an informative march through the sordid history of Linux audio, most of which I have battled with at one time. Linux audio can be quite powerful, a Swiss Army Knife with 99 blades; just be careful when using a blade you don't cut yourself on one of the other 98 blades. Cheers!
This is a really great explainer on a rather confusing subject.
Wow! I did not expect this to be so informative.
By the end of the video, you have put every concept, you had introduced in the beginning, together so clearly.
Thank you, really.
Thanks for the kind words!
Your voice is so calming I always drift off! Had to reattach this video couple of times
You have a talent for explaining things clearly. Thanks.
Thanks for the kind words!
You are the man!!! You finally helped me understand how all these different processes work on my Linux machine. Your approach to explaining everything was genuinely balanced with simplicity --yet covering all the nuances of the interplay. Bravo!!
Glad I could help!
Thanks man. It's the only video on Linux audio explained in much detail.desperately required video.
Thanks for the kind words, glad you found it useful!
This video was exactly what i searched for, thank you, it was very informative
Hi Tony, thanks for all the info you've put together here. I've been editing and recording for over a decade on mainstream platforms, and only recently have started to delve into the Linux side of audio. All these bits and pieces of info are of great help! :D
Everytime I am going to explain this to anyone I am going to remember you !!! Thanks for this consolidated information.
I almote Broke my system while getting my Bluetooth Headset (Microphone) work. But I think I will give up on Bluetooth Headphones atleast for Meetings.
Great to have all those technologies, their pros and cons and the relation between them explained in one video - thank you!
Thanks! Glad you found it useful!
Thanks for taking the time to explain this!
Finally, ... I have been waiting so long for a explanation of this. Thanks Tony!
Thanks! Glad you found it helpful!
That was a first class system overview; your video really helped me to picture how it all 'bolts together'. Using qpwgraph, I've just set up the laptop microphone -> EasyEffects (so I can use eq, multi-band compression, etc) -> wfview (which then 'feeds' audio to and controls an Icom IC-705 transmitter on my network) and it's all working an absolute treat. All I have to do now is spend a ludicrous amount of time setting up all the EasyEffects components in an attempt to make it sound good(ish). 🙂 Assuming it sounds okay (long story about Icom codecs omitted to save space), the next stage will be to set all this up in a headless Linux box (with a decent audio interface and microphone) and try to emulate an Orban 9105A Optimod-HF using EasyEffects; I might be gone for quite some time! 😀
great work, very informative!
just a footnote: the minimum sampling frequency must always be at least 2x the max frequency being "recorded", otherwise spectral info could be lost, as stated by the Sampling Theorem (Nyquist-Shannon). so even if we can only hear up to ~20kHz we actually need at least ~40kHz in sampling frequency. in reality the distortion caused by the sampling process is almost imperceptible to most people but it exists, and human hearing ranges may vary as well
You are absolutely correct about needing at least double the frequency to capture the original information as per the Nyquist-Shannon sampling theorem - hence most sound cards running at 48 kHz these days.
If you're interested, Chris Montgomery also has a great video exploring and demonstrating the sampling process as well as effects quantizing the input over on Xiph's website: xiph.org/video/vid2.shtml
Thanks for this video! Been having a ton of audio issues, and this should help me fix them, once I understand it a bit better. Much appreciated! Deserved sub!
Thank you for the clear and easy to understand breakdown. I am new to Linux audio, and I'll need to learn a lot because I'm also building a Linux recording setup with Ardour as my centerpiece.
Many thanks for the explainatiom - thorough and easy to follow! 👌
Finally I understand how alsa and pulseaudio interact, and how they relate to OSS! Thanks for the excellent video! Tips for future vids - more b-roll and perhaps slow down a bit
Thanks for the kind words! Early on, I used to try to get b-roll, but then I started to dread making videos (and I couldn't think of much to film for b-roll for a sound server), so I reverted to back simpler filming and editing... As for slowing down, yeah, it's something I need to work on, it kind of 'just happens' when I get a little passionate.
thanks man, finally a complete overall look at linux audio systems. keep it up!!
Thanks man!!! Never saw somebody explain that so well
thanks so much for this overview! there aren't that many beginner-friendly explanations of how linux's audio backend works!!
Thanks for the kind words, glad it was helpful!
Thank you! Very well explained. I have a small music studio and Linux has become my OS of choice in the past year. My Linux skills have not yet been up to the task and I have had to use ALSA exclusively. Pipewire is intriguing me and I will give that a shot. I have one small suggestion for you. If you put a foam pop filter over that mic, your audio would be much improved. Have an awesome day!
Man this was a great and comprehensive explanation. And also very fun to watch.
Thanks !
Thanks for the kind words, glad you enjoyed it!
Lovely vid Tony, quite clarifying.
Thanks for the kind words!
Great explanation, thank you for the information you've provided! 😎
Thank you Tony I really needed a video like this
This is such a good video holy shit! I have been losing my mind over what these software were and briefly explained all their purpose holistically. Thanks!
Great video! First time seeing your channel, subscribed! I'm definetly the audience for this type of videos.
Thanks for the kind words!
@10:17 , i have just learnt that i could sync all my daws thanks to jack. This was the best take away from this video for me. Mükemmel!!!
:)
Thank you for these interesting explanations!
This video was super helpful. Thank you a lot for making it!
Thanks for the kind words, glad it was helpful!
Really good explanation. Thanks!
Worth every second of my life listening to this. Thumbs up for quickly orienting me on one piece of this confusing morass that is Linux audio technology.
Thanks for the kind words, glad you found it helpful!
Excellent video bro! I been doing Linux Audio off an on for a couple decades now and only learned enough to navigate and utilize these various apps you mentioned without ever really understanding their interactions. Just getting ready to give it a try again since winter is upon us already. That was super cool! Thanks!
Thanks for the kind words!
TNice tutorials is actually a very good and straight forward tutorial. No having ask questions or guess, no over-explaining elents, and brings
Thanks for the kind words!
Thanks man. I'm strating on linux and your talk opened my mind. Thanks a lot!
Glad I could help!
Great explanation! Thanks Tony!
Thanks!
that was a really great overview. thanks for making this
Thanks, glad it was helpful!
Thank you for the excellent explanation. Greatly appreciated.
Thanks!
Thanks for sharing this information. If possible can you please keep making these kind of videos?
This was amazing! Thank you!
Amazing explanation. Thank you!
Glad it was helpful!
Loved your explanation! Thank you!
Thanks!
Brilliant explanation. Thanks!
Glad it was helpful!
Amazing video, man! Congratulations, I've just subscribed ;)
Thanks! Glad you found it interesting!
Very helpful Tony, thanks for your educated perspective on all of this! -Jan
Thanks for the kind words Jan, glad you enjoyed it!
A lot of ppl have over the years commented on the messiness and confusion around linux sound and could there be an easier way to deal with it. I have used alsa from the command line and pulseaudio via a gui. Not used Jack as I don't mix sound. Pipewire I've not heard of prior to watching this video. An instructive video which explains the basic differences between the various pieces of software and how they interact to provide sound capability for Linux which can be a bit overwhelming for Linux newbies. Keep up the good work.
Great explanation. Thanks!
Glad it was helpful!
Thank you so much for the video. I’m running a development desktop with Ubuntu 20.xx. All my standard devices are working, but I’m trying to test some USB audio output and work with the latency. This really helped with your explanation of the audio servers etc. Thanks again
Thanks, glad you found it useful!
Thanks man, exactly what I needed to learn
Glad it helped!
Harika! Sunum için teşekkürler. :)
Very informative, thank you!
Thanks for the kind words!
Amazing video, Thank you very much for your effort!
My pleasure! Glad you enjoyed it!
Dude, you cleared a bunch of doubts I had in just 20 minutes! I bought an old Makie Onix-i 16 channel mixer that only works (so they say - I haven't tested) in linux. Also, the UbuntuStudio distro with the low latency driver is wonderful!
A curiosity: in the old days of 100MHz CPUs, mixing audio was heavy for the processors and digital telephone switchers were built with those processors and requried not low-latency but real-time OS and programming. It was so difficult only 8 countries managed to design and produce them.
Great video, very informative. I wish I could hear it.
Great video! It helped me to organize and understand how things work and why some doesn't work here. I have a Firewire M-Audio 410 here and after moving from pulseaudio + jack to pipewire (0.3.39 on Debian here) I noticed that artifacts you mention at 13:25 when recording from my microphone on the onboard soundcard and the guitar plugged into firewire on ardour. When there is no ardour on the way, just connecting the input of M-Audio to guitarix or rakarrak and then to HDMI, the sound is perfect.
It seems to be some resampling issue between the M-Audio and onboard sound card, right? Should I completely remove pulseaudio and jack to have things working well here? I manage the connections using qjackctl, is there some similar alternative?
Thanks again for the great video!
Excellent! Thank you.
10:03 One reason PulseAudio makes things easier is it basically slots in under the ALSA API. So apps that know about ALSA automatically work with PulseAudio, without noticing the extra PulseAudio layer between them and the actual hardware.
Worked! What an absolute genius mad lad! Was so easy
Linux Audio is why I daily drive a hackintosh, despite being very keen to switch to Linux. I'm hoping that as Pipewire matures everything gets a lot simpler and easier. Thank you for the video, at least I now have a better grasp of the issues.
Glad you found the video useful!
I remember I thought the same but for OS X audio when I had to use it for a job. Drove me crazy for a bit back then trying to find a way to capture both the system output and microphone input, which I could do on Windows and Linux.
Great! useful and informative.
Keep up the good work!!! There's a lot of information out there.
Few people are able to dive deep into it and explain the way you did!
Regarding a few comments about your hair... Embrace it!!!
If i were you, i'd even hang an Einstein poster in the background.
Awesome people try to help other's succeed. Hater's try to stop other's success!
You're awesome!!! Keep it up Boss!!!
ABSOLUTELY... EXcellent!!! thanks
Great video, thank you!
Thanks!
Thanks a lot for this introduction
Thanks for the kind words!
Good explanation, Thanks.
thx buddy for the explanation, it helped me!
Happy to have helped!
Thanks mate. That was very useful.
Thanks for the kind words!
Very nice information Sir
Using PipeWire for almost two years now and I'm happy to announce that the BT device being "there" but not outputting any beep at all is back again :D Usually resolved by restarting the headphones 😩 From a gut feeling it's probably some chip going into energy saving mode after the last stream closed and it may be related to the headphones themselves. They did start to develop weird glitches over the time (especially the ANC feature) so there's that. Anyway, will totally stick with PipeWire. It really changed everything for me. And that's coming from someone who remembers how to echo "magic integers" into OSS device nodes to get sound going for some really odd native Linux PC games back in the days :D
This was super useful, thanks
Thanks, glad you found it useful!
Nice. Finally getting around to moving from xorg to wlroots and pulseaudio to pipewire... I'm a bit of a dinosaur haha so the time has come, been, gone and come again. This was really useful for clarifying some assumptions I'd made about... stuff. Cheers!
Great info man!
Thanks!
goated video!
wow this is such a informative video! thanks
Thanks for the kind words!
Great video, transferred to Linux not long ago, and all of that information was messed up in my head. Thanks.
Glad you found it helpful!
thanks i learned something new today
Great video, thanks for that!
Thanks for the kind words, glad I could help!
Great content!
This is the best free software Ive seen. Respect.
Awesome job, dude.
Thanks!
Stumbled upon this video while searching for a way to get pipewire to output 5.1 surround audio via S/PDIF. Very informative and while it didn't solve my problem, at least I now know more about PulseAudio and Pipewire. Researching resumes...
Hm, you are probably right. I remember that 5.1 wasn't fully implemented working in Pipewire last year.
While I don't have an SPDIF output or a 5.1 setup to check on my current system, I checked the supported HDMI profiles and it does allow for a 5.1 or 7.1 output (as well as allowing 5.1 digital output on my old SoundBlaster), so it might be possible using HDMI instead if it isn't supported over optical.
I have a 5.1 sound interface connected via USB. All the 6 channels show up for separate connection in qpwgraph, and I was able to route audio to them separately.
very nice video, thanks a ton!
Thanks for the kind words!
Thanks for reminding me of EMU10k1
Good information.