audio-stream-silence works only for short pause

[arvidjaar]

mpv version and platform

0.21.0, Ubuntu 16.04, kernel 4.8.0-25,
00:1b.0 Audio device [0403]: Intel Corporation Wildcat Point-LP High Definition Audio Controller [8086:9ca0] (rev 03)
Subsystem: Dell Wildcat Point-LP High Definition Audio Controller [1028:062b]
Kernel driver in use: snd_hda_intel
Kernel modules: snd_hda_intel

0 [HDMI ]: HDA-Intel - HDA Intel HDMI
HDA Intel HDMI at 0xf733c000 irq 52
1 [PCH ]: HDA-Intel - HDA Intel PCH
HDA Intel PCH at 0xf7338000 irq 51

Reproduction steps

Set

audio-stream-silence=yes

Start video playback on HDMI connected TV. Pause playback. Wait several minutes and resume.

Expected behavior

There is no silence when playback starts.

Actual behavior

There is initial silence when playback starts, especially annoying when some dialogue is going on. This does not happen for short pause (several seconds) where audio resumes instantly.

Log file

https://gist.github.com/arvidjaar/0a06e2394d8e4f76918255f998185631

Sample files

Any normal video stream

[ghost]

There is no silence when playback starts.

You'd need to combine it with --audio-wait-open=. --audio-stream-silence merely streams silence when no audio is playing, while adding --audio-wait-open would "prime" the audio device with silence before sending real audio data to it.

Unfortunately, --audio-stream-silence is not implemented for Pulse, only alsa/wasapi/coreaudio/jack/sdl. ao_alsa implements it by special API usage (makes it stream silence on underflow), so this is not necessarily easy to add to Pulse.

But in general I'd expect Pulse server to handle this, due to its aspiration of "doing the right thing" and managing audio devices directly, rather than leaving it to applications.

[ghost]

(Actually looking again you enable --audio-wait-open.)

[arvidjaar]

Unfortunately, --audio-stream-silence is not implemented for Pulse

Well, would be helpful if it also said so, at least in verbose mode :) I'll try to raise it up with PA.

[ghost]

Well, the manpage says Not all AOs support this..

[ghost]

Pushed a change that will cause ao_pulse.c to explicitly play silence as well. Also will probably lead to new problems.

[arvidjaar]

Thanks! Will have to wait until next release to test and report.

[ghost]

The next release is probably in a few months.

[arvidjaar]

I tried mpv at commit 51fd8f6 - as far as I understand it should include this change. It did not help, I still see the same lack of sound after resuming from pause with PA. With ALSA there is no gap.