a52 plugin not working with PipeWire

[sjnewbury]

Using the lastest code since v1.2.5 I can successfully get AC3 output through HDMI when using speaker-test. Defaults use a huge buffer and gives terrible latency, but it works.

PulseAudio also works fine with fairly low-latency using "tsched=1 tsched_buffer_size=32768 tsched_buffer_watermark=8192 fixed_latency_range=yes mmap=1". This doesn't need the rate kludge any more.

When I try pipewire using mmap I get the below messages in the log, no audio:

spa.alsa: alsa-pcm a52hdmi: mmap_commit wrote 512 instead of 1024

With mmap disabled, no errors are reported, but still no sound.

Is there a configuration for pipewire which works with the a52 plugin, a pipewire bug, or is this another a52 plugin bug?

[sjnewbury]

Another issue with a52/pipewire which also applies to PulseAudio, is the a52 plugin doesn't support config functions for the slavepcm which makes it impossible to have automatically generated profiles for AC3 output. WIth the dca plugin, just adding confdir:pcm/dca.conf to asound.conf makes DTS profiles selectable from pavucontrol.

[perexg]

Another issue with a52/pipewire which also applies to PulseAudio, is the a52 plugin doesn't support config functions for the slavepcm which makes it impossible to have automatically generated profiles for AC3 output. WIth the dca plugin, just adding confdir:pcm/dca.conf to asound.conf makes DTS profiles selectable from pavucontrol.

Can you test this config ? perexg@9a74090

[perexg]

When I try pipewire using mmap I get the below messages in the log, no audio:

spa.alsa: alsa-pcm a52hdmi: mmap_commit wrote 512 instead of 1024

This should be probably harmless, but yes, it appears like another minor issue in the a52 plugin. I suspect that the end PCM device does not consume the samples in the right time.

Is there a configuration for pipewire which works with the a52 plugin, a pipewire bug, or is this another a52 plugin bug?

You may try to enable the debug log level in PW and check the input from PW to the plugin.

[DocMAX]

how did you set up a52 on pipewire?