Muting is delayed with ao_avfoundation

mpv Information

mpv 0.39.0 Copyright © 2000-2024 mpv/MPlayer/mplayer2 projects
libplacebo version: v7.349.0
FFmpeg version: 7.1
FFmpeg library versions:
   libavcodec      61.3.100 (runtime 61.19.100)
   libavdevice     61.1.100 (runtime 61.3.100)
   libavfilter     10.1.100 (runtime 10.4.100)
   libavformat     61.1.100 (runtime 61.7.100)
   libavutil       59.8.100 (runtime 59.39.100)
   libswresample   5.1.100 (runtime 5.3.100)
   libswscale      8.1.100 (runtime 8.3.100)

Other Information

- macOS version: Sequoia 15.0.1
- Source of mpv: Homebrew
- Introduced in version: 0.39.0

Reproduction Steps

Play any video with --no-config --ao=avfoundation and toggle mute (either by using the keybind or using the menu bar).

Expected Behavior

Same behaviour as ao_coreaudio, which mutes as soon as toggled.

Actual Behavior

It takes at least a second to actually mute the audio.

Log File

output.txt

Sample Files

No response

I carefully read all instruction and confirm that I did the following:

• I tested with the latest mpv version to validate that the issue is not already fixed.
• I provided all required information including system and mpv version.
• I produced the log file with the exact same set of files, parameters, and conditions used in "Reproduction Steps", with the addition of --log-file=output.txt.
• I produced the log file while the behaviors described in "Actual Behavior" were actively observed.
• I attached the full, untruncated log file.
• I attached the backtrace in the case of a crash.

Reproduce with mpv --no-config --ao=avfoundation and toggle mute, then compare the behavior with ao_coreaudio using the attached output.txt log. Start at the ao_avfoundation and ao_coreaudio audio backends. Done means muting takes effect immediately with ao_avfoundation, matching ao_coreaudio.