PipeWire: The Linux audio/video bus • Hacker News Board

Re: PipeWire: The Linux audio/video bus

#101

Post by _pmf_ » Wed, Mar 03, 2021, 5:42 PM UTC

bluGill wrote: post #71

war1025 wrote: post #50

Earlier quoted context omitted.

My understanding back in the mid 2000s when I first got into Linux was that OSS only let you play one audio stream at once, and the whole point of ALSA was that it let multiple applications access the sound card. I guess I could be remembering that wrong, but I know I was listening to multiple audio streams long before PulseAudio came onto the scene.

OSS in non-free versions supported multiple sources. Linux sound guys decided that instead of fixing the free OSS they would write ALSA. They never really worked out all the bugs around mixing before pulseaudio took over.

OSS was the last time I had Linux audio in a state that I would call "basically working".

Re: PipeWire: The Linux audio/video bus

#102

Post by tremon » Wed, Mar 03, 2021, 5:42 PM UTC

symlinkk wrote: post #95

I have never had problems with audio on Linux. What problems does this solve?

Same thing that ALSA, esd, Pulseaudio and Phonon solved: the previous incarnation itched.

Re: PipeWire: The Linux audio/video bus

#103

Post by moistbar » Wed, Mar 03, 2021, 5:50 PM UTC

Does anyone know if PipeWire can do audio streaming like PulseAudio can? I had a rather nice setup using a raspberry pi and an old stereo system a while back that I'd like to replicate.

Re: PipeWire: The Linux audio/video bus

#104

Post by grawprog » Wed, Mar 03, 2021, 5:52 PM UTC

>JACK applications are supported through a re-implementation of the JACK client libraries and the pw-jack tool if both native and PipeWire JACK libraries are installed in parallel

>unlike JACK, PipeWire uses timer-based audio scheduling. A dynamically reconfigurable timer is used for scheduling wake-ups to fill the audio buffer instead of depending on a constant rate of sound card interrupts. Beside the power-saving benefits, this allows the audio daemon to provide dynamic latency: higher for power-saving and consumer-grade audio like music playback; low for latency-sensitive workloads like professional audio.

That's pretty interesting. It sounds like it's backwards compatible with jack programs but uses timer based scheduling similar to pulseaudio. Can you actually get the same low levels of latency needed for audio production without realtime scheduling?

JACK's used over pulse for professional audio typically because of its realtime scheduling. How does pipewire provide low enough latency for recording or other audio production using timer based scheduling?

Does anyone have any experience using pipewire for music recording or production?

It would be nice to have one sound server, instead of three layered on top of eachother precariously, if it works well for music production.

Re: PipeWire: The Linux audio/video bus

#105

Post by Abishek_Muthian » Wed, Mar 03, 2021, 5:53 PM UTC

chenxiaolong wrote: post #10

I've been trying out the latest master builds of pipewire recently and have been pretty impressed with it: * My bluetooth headset can now use the HFP profile with the mSBC codec (16 kHz sample rate) instead of the terrible CVSD codec (8 kHz sample rate) with the basic HSP profile. * Higher quality A2DP stereo codecs, like LDAC, also work. * AVDTP 1.3 delay reporting works (!!) to delay the video for perfect A/V sync.…

Would there be improvements for remote audio streaming over pulseaudio with ssh?

Re: PipeWire: The Linux audio/video bus

#106

Post by cycloptic » Wed, Mar 03, 2021, 5:57 PM UTC

moistbar wrote: post #103

Does anyone know if PipeWire can do audio streaming like PulseAudio can? I had a rather nice setup using a raspberry pi and an old stereo system a while back that I'd like to replicate.

TCP sockets appear to still be supported by pipewire-pulse.

Re: PipeWire: The Linux audio/video bus

#107

Post by cptn_brittish » Wed, Mar 03, 2021, 6:38 PM UTC

pkulak wrote: post #65

ledbettj wrote: post #9

Earlier quoted context omitted.

It also worked as drop in replacement for PulseAudio for me, except all my audio now had stutters and pops. I ended up going back to Pulse. I got suggestions that I could go tweak buffer sizes stuff in a config file somewhere, but for my simple desktop use case I'd rather my audio just sounds right out of the box. Hopefully this sort of thing gets straightened out, because having to muck with config files to make my…

I had a couple little issues as well when I switched over a couple months ago, but they just fell away over the ensuing weeks of updates until there's nothing left at the moment. Give it another try sometime soon.

I can confirm that a issue causing my audio to completely drop at random points resolved about 1 month ago and now everything works perfectly.

Re: PipeWire: The Linux audio/video bus

#108

Post by cptn_brittish » Wed, Mar 03, 2021, 6:40 PM UTC

xorcist wrote: post #6

What does real world latency look like with Pipewire? Is it comparable to jackd when used with something like Ardour?

It has a jack and pulseaudio api wrapper. I use it because it means I don't need to muck around with configuring pulse and jack to work nicely together.

Re: PipeWire: The Linux audio/video bus

#109

Post by cycloptic » Wed, Mar 03, 2021, 6:47 PM UTC

bluGill wrote: post #71

war1025 wrote: post #50

Earlier quoted context omitted.

My understanding back in the mid 2000s when I first got into Linux was that OSS only let you play one audio stream at once, and the whole point of ALSA was that it let multiple applications access the sound card. I guess I could be remembering that wrong, but I know I was listening to multiple audio streams long before PulseAudio came onto the scene.

OSS in non-free versions supported multiple sources. Linux sound guys decided that instead of fixing the free OSS they would write ALSA. They never really worked out all the bugs around mixing before pulseaudio took over.

It's more than 20 years later and still I don't understand these complaints. ALSA was designed to have a broader API than OSS, and it has supported OSS emulation for quite some time. What else could have been done when OSS went non-free?

Re: PipeWire: The Linux audio/video bus

#110

Post by pta2002 » Wed, Mar 03, 2021, 6:53 PM UTC

severino wrote: post #97

pta2002 wrote: post #5

Just tried it on NixOS, had no idea it was so fleshed out already! Thought it'd be full of bugs but was pleasantly surprised, it just worked. No issues with compatibility, extremely low latency and has JACK and PulseAudio shims, so everything works out of the box, including pro audio stuff like Reaper and Ardour. And thanks to the JACK shim I can patch around the outputs with qjackctl. This is compared to JACK, which…

I gave JACK a try more than a decade ago, and I remember how cool it was to be able to pipe the audio from one application to the input of another (unrelated) app, possibly adding effects or transformations in between. But JACK never became "mainstream" so I never got to use it for anything serious, but I miss the flexibility it offered even for non professional use-cases. What I wonder is if PipeWire will allow this…

It does, exactly the same way as JACK, and you can even do it with pulseaudio apps! I could pipe audio from a firefox tab through guitarix (guitar amp emulator) into a second firefox tab if I wanted to. With just JACK or just Pulse this wouldn't be possible. And if I understand it correctly, it should work for video streams too. I'm imagining piping a screenshare through OBS before going into discord or something, should be very useful.