Package: ffmpeg Version: 7:5.1.6-0+deb12u1 Severity: normal X-Debbugs-Cc: krzpyrk...@gmail.com
Dear Maintainer, -f pulse cuts last 2-3 seconds of audio when stopped by hitting "q". How to reproduce: I observed the behavior by recording screen with x11grab for video and pulse for audio. Last 2 seconds of audio are missing in every file. Start playing music in the background (with mpv, or whatever program), then start recording (substitute the alsa_output...monitor for your device name, it can be obtained with "pactl list short sources"): $ ffmpeg -y -f x11grab -i "$DISPLAY" -f pulse -i alsa_output.pci-0000_05_00.6.analog-stereo.monitor /tmp/recording.mp4 The video will be fully recorded, the audio will stop 2 seconds before the end, even though it was still being played when pressing "q". I decided to split video and audio with -map to separate files to measure the stream length, and indeed audio is shorter: $ ffmpeg -y -f x11grab -i "$DISPLAY" -f pulse -i alsa_output.pci-0000_05_00.6.analog-stereo.monitor -map 0:v /tmp/foo.mp4 -map 1:a /tmp/foo_audio.mp4 $ ffprobe /tmp/foo_audio.mp4 |& grep Duration Duration: 00:00:02.08, start: 0.000000, bitrate: 135 kb/s $ ffprobe /tmp/foo.mp4 |& grep Duration Duration: 00:00:04.37, start: 0.000000, bitrate: 912 kb/s It's not an issue with x11grab. Passing an arbitrary file in its place (-i something.mp4) produces the same effect with the audio being 2-3 seconds shorter. The audio is not cut when total recording length is specified beforehand, with -t 15. It happens only when "q" is hit. I confirmed the problem exists on ffmpeg versions 5.1, 7.1 (Debian stable/sid), x86 and arm64. There's no difference between the pulseaudio or pipewire-pulse as the backend. It seems to me it is a Debian-specific problem - I built ffmpeg 6.0, 7.0 and 7.1 locally, from the ffmpeg release tarballs, without dpkg, and the length of audio is the same as video. Another Debian user reproduced the problem as well. Regards, Krzysztof
