libmpv: using multiple mpv instances ffmpeg errors are sent to the wrong instance

[wbtcpip2]

mpv Information

[ 569.139][v][cplayer] mpv v0.38.0-601-gf470b63a Copyright © 2000-2024 mpv/MPlayer/mplayer2 projects
[ 569.139][v][cplayer]  built on Jul 12 2024 00:08:04
[ 569.139][v][cplayer] libplacebo version: v7.349.0 (v7.349.0-dirty)
[ 569.139][v][cplayer] FFmpeg version: N-116241-g70c6b904b
[ 569.139][v][cplayer] FFmpeg library versions:
[ 569.139][v][cplayer]    libavcodec      61.10.100
[ 569.139][v][cplayer]    libavdevice     61.2.100
[ 569.139][v][cplayer]    libavfilter     10.2.102
[ 569.139][v][cplayer]    libavformat     61.5.101
[ 569.139][v][cplayer]    libavutil       59.28.100
[ 569.139][v][cplayer]    libswresample   5.2.100
[ 569.139][v][cplayer]    libswscale      8.2.100

Other Information

- Windows version:Windows 10 Pro 64-bit (10.0, Build 19045) (19041.vb_release.191206-1406)
- GPU model, driver and version:AMD Radeon(TM) Graphics 31.0.21914.4000
- Source of mpv: https://github.com/wbtcpip2/mpv-winbuild/actions/runs/9899851878
- Introduced in version: since longtime

Reproduction Steps

in my process i run multiple instances of libmpv playing several videos at the same time. for each instance i use MPVSetPropertyString(mpvhandle, "log-file", filename) MPVSetPropertyString(mpvhandle, "msg-level", "all=debug")

lately when i look at the log files i see that ffmpeg errors are sometimes notified to the wrong instance

example, i have one instance only playing a png picture and another instance playing an mp4 video file now take a look to the log of the pngfile: 17092024_211921_DGB32Graphicsbackground2png.txt

in that log you'll see some ffmpeg error related to h264, that errors comes from another instances:

17092024_212108_ZCanzoniCanzoniDJKayzfeatNazaKeblackComDabmp4.txt

Expected Behavior

each mpv instance must log the errors related to the proper instance.

Actual Behavior

randomly ffmpeg/lavf messages of another mpv instance are logged

Log File

log of png image (with h264 errors of another instance) 17092024_211921_DGB32Graphicsbackground2png.txt

log of a h264 stream (there are no errors here, because they was notified to the wrong instance) 17092024_212108_ZCanzoniCanzoniDJKayzfeatNazaKeblackComDabmp4.txt

Sample Files

No response

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

• [X] I tested with the latest mpv version to validate that the issue is not already fixed.
• [X] I provided all required information including system and mpv version.
• [X] 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.
• [X] I produced the log file while the behaviors described in "Actual Behavior" were actively observed.
• [X] I attached the full, untruncated log file.
• [X] I attached the backtrace in the case of a crash.