roc-toolkit: roc-send not working with pulseaudio source

As discussed in matrix…

pi@dev1:~ $ pulseaudio --version
pulseaudio 14.2

pi@dev1:~ $ roc-send  --version
roc-send 0.2.0 (ed92e21e98)
pi@dev1:~ $ roc-send --list-supported
supported schemes for audio devices and files:
  pulse:// alsa:// oss:// file://

supported formats for audio files:
  .aifc .aiffc .aiff .aif .al .au .snd .avr .cdda .cdr .cvsd .cvs .cvu .dat
  .dvms .vms .f32 .f64 .gsrt .hcom .htk .ima .la .lu .maud .prc .s8 .s16
  .s24 .s32 .sf .ircam .sln .smp .sndr .sndt .sox .sph .nist .8svx .txw
  .u8 .sou .fssd .u16 .u24 .u32 .ul .voc .vox .wav .wavpcm .amb .wve .xa

pi@dev1:~ $ roc-send -vvvv --input pulse://alsa_input.usb-C-Media_Electronics_Inc._USB_Audio_Device-00.mono-fallback --source rtp+rs8m://10.9.6.96:10001 -
-repair rs8m://10.9.6.96:10002
14:52:31.481 [4967] [dbg] roc_core: [slab_pool.cpp:38] slab pool: initializing: object_size=672 min_slab=0B(1S) max_slab=0B(0S) poison=0
14:52:31.481 [4967] [dbg] roc_core: [slab_pool.cpp:38] slab pool: initializing: object_size=2064 min_slab=0B(1S) max_slab=0B(0S) poison=0
14:52:31.481 [4967] [dbg] roc_core: [slab_pool.cpp:38] slab pool: initializing: object_size=4112 min_slab=0B(1S) max_slab=0B(0S) poison=0
14:52:31.482 [4968] [dbg] roc_netio: [network_loop.cpp:278] network loop: starting event loop
14:52:31.482 [4967] [dbg] roc_peer: [context.cpp:25] context: initializing
14:52:31.482 [4967] [dbg] roc_sndio: [pulseaudio_backend.cpp:19] pulseaudio backend: initializing
14:52:31.482 [4967] [dbg] roc_sndio: [sox_backend.cpp:164] sox backend: initializing
14:52:31.482 [4969] [dbg] roc_ctl: [control_task_queue.cpp:95] control task queue: starting event loop
14:52:31.483 [4969] [trc] roc_ctl: [control_task_queue.cpp:706] control task queue: ready task queue is empty or being pushed
14:52:31.483 [4969] [trc] roc_ctl: [control_task_queue.cpp:839] control task queue: updating wakeup deadline: deadline=-1
14:52:31.483 [4967] [dbg] roc_sndio: [backend_map.cpp:20] backend map: initialized: n_backends=2 n_drivers=58
14:52:31.483 [4967] [err] roc_sndio: [backend_dispatcher.cpp:208] backend dispatcher: failed to open source: type=device driver=pulse path=alsa_input.usb-C-Media_Electronics_Inc._USB_Audio_Device-00.mono-fallback
14:52:31.483 [4967] [err] roc_send: [main.cpp:255] can't open input file or device: uri=pulse://alsa_input.usb-C-Media_Electronics_Inc._USB_Audio_Device-00.mono-fallback format=(null)
14:52:31.483 [4967] [dbg] roc_peer: [context.cpp:29] context: deinitializing
14:52:31.484 [4969] [trc] roc_ctl: [control_task_queue.cpp:706] control task queue: ready task queue is empty or being pushed
14:52:31.484 [4969] [trc] roc_ctl: [control_task_queue.cpp:839] control task queue: updating wakeup deadline: deadline=-1
14:52:31.484 [4969] [dbg] roc_ctl: [control_task_queue.cpp:105] control task queue: finishing event loop
14:52:31.484 [4968] [dbg] roc_netio: [network_loop.cpp:285] network loop: finishing event loop

pi@dev1:~ $ pactl list sources  short
3       alsa_output.usb-C-Media_Electronics_Inc._USB_Audio_Device-00.analog-stereo.monitor      module-alsa-card.c      s16le 2ch 44100Hz       SUSPENDED
4       alsa_input.usb-C-Media_Electronics_Inc._USB_Audio_Device-00.mono-fallback       module-alsa-card.c      s16le 1ch 44100Hz       SUSPENDED

gavv Thanks. I think I know where is the bug (in backrnd dispatching code).

As a temporary workaround, could you try to use -i alsa://pulse ?

About this issue

Original URL
State: closed
Created 2 years ago
Comments: 15 (10 by maintainers)

Most upvoted comments

I see, thanks. I thought you’re also streaming from mic.

BTW you can also use pipewire modules for roc.

I’d recommend putting the discussion page you wrote in the docs, it’s quite helpful and would become more discoverable.

Definitely, it’s on my TODO.

I’m closing this. @Ramblurr feel free to reopen if needed!

gavv on Mar 27, 2023

Thanks for checking!

Somehow it’s still not going below 100ms on localhost but maybe I’m handling this wrong.

If you mean overall latency from sender input to receiver output, you can:

use --io-latency on sender, as you’re already doing, to reduce PulseAudio recording latency (default 60ms)
use --io-latency on receiver too, to reduce PulseAudio playback latency (default 60ms)
use --sess-latency on receiver, to reduce session pipeline latency (default 200ms)
when you reduce session latency, you may need to reduce FEC block size as well; FEC block duration should be always smaller than session latency;
FEC block duration is defined by three parameters of roc-send:
- --nbsrc (number of source packets in block, default 20)
- --nbrpr (number of repair/redundancy packets in block, default 10)
- --packet-length (duration of single packet; default 7ms)
default values for FEC give 20 * 7ms = 140ms minimum allowed session latency; you can reduce --nbsrc and/or --packet-length to reduce minimum allowed session latency; meaningful values for --nbrpr is something in range [nbsrc/2; nbsrc]

gavv on Mar 25, 2023

@zopieux I’ve pushed a fix for the latency to develop branch (cafa5a49327763a4b7a3ab9e45e2a8fb22dbc7ec). Pulseaudio part of the latency by default is about 60ms now.

I also added --io-latency option to roc-send (d65cfbfa5d5ad853f0c07b1010137cb66304d610), which allows to set that part of the latency manually. In my experience, on many devices you can safely set it to 20-30 ms, and sometimes even lower. (but usually you need rtkit for that).

gavv on Mar 25, 2023

Thanks for testing and report!

The high latency is not expected, it should be possible to set pulseaudio part of the latency from ~15s to ~60ms depending on device, and 60ms is expected to be default (since it works well for most devices).

I was able to reproduce it, looking into it.

gavv on Mar 24, 2023

I’ve added pulseaudio source support to develop branch. It will be part of next release.

Example:

roc-send -vv -s rtp+rs8m://lo:10001 -r rs8m://lo:10002 -i pulse://<source_name>

You’re welcome to test it 😃

https://github.com/roc-streaming/roc-toolkit/issues/312

gavv on Mar 13, 2023

@zopieux Hi,

You can try to set PULSE_SOURCE environment variable. Hopefully, ALSA pulse device will use it.

If not, I think after starting roc-send you can just open pavucontrol, open “recording” tab and connect roc-send to needed source:

You you can do the same using pactl move-source-output.

When you restart roc-send, pulseaudio should remember your last choice, however this functionality sometimes does not always behave as you can expect.

gavv on Mar 7, 2023