Opened 6 years ago

Last modified 6 months ago

#4703 new defect

Audio cut off in screencast

Reported by: Kai Hendry Owned by:
Priority: normal Component: undetermined
Version: unspecified Keywords:
Cc: Neven Sajko Blocked By:
Blocking: Reproduced by developer: no
Analyzed by developer: no

Description

Summary of the bug: Last second or two of audio is cut off during a screencast: http://s.natalian.org/2015-07-08/cutoff.mp4

How to reproduce:

% ffmpeg -v warning -f x11grab -video_size 1920x1080 -i :0 -f alsa -i pulse -acodec pcm_s16le -c:v libx264 /tmp/cutoff.mkv &>> /tmp/r2d2.log &
ffmpeg version 2.7.1
built on Archlinux

When i kill ffmpeg during a screencast, my voice is cut off http://s.natalian.org/2015-07-08/cutoff.mp4
Here is the log http://s.natalian.org/2015-07-08/cutoff.txt

Regular kill and kill -INT $pid has the same problem.

Source of my script: https://github.com/kaihendry/recordmydesktop2.0/blob/master/x11capture

Change History (10)

comment:1 by Kai Hendry, 6 years ago

I can confirm the bug with the pulse audio line from https://trac.ffmpeg.org/wiki/Capture/Desktop ffmpeg -video_size 1024x768 -framerate 25 -f x11grab -i :0.0+100,200 -f pulse -ac 2 -i default output.mkv

comment:2 by Carl Eugen Hoyos, 6 years ago

First steps to make this a valid ticket are to test current FFmpeg git head and provide the command line that allows to reproduce the issue together with the complete, uncut console output here on the bug tracker.
Is the issue also reproducible if you press "q"?

comment:3 by Kai Hendry, 6 years ago

I just built from git head ffmpeg version N-73452-g80e4238 and the problem exists. http://s.natalian.org/2015-07-08/1to5.mkv

Yes, I pressed "q" to stop the video after saying five.

comment:4 by Elon Musk, 6 years ago

Does it also happens if you only record audio without video?

comment:5 by Kai Hendry, 6 years ago

It does not happen when I record just with audio: http://s.natalian.org/2015-07-09/sound-only.mkv with ffmpeg -f pulse -i default sound-only.mkv.

I believe this to be a fairly recent (last two months?) regression, but I don't have time to bisect atm.

comment:6 by Fredrick Brennan, 6 years ago

This is happening to me as well. The last few seconds of my voice get cut off. Arch Linux as well.

comment:7 by Elon Musk, 5 years ago

Happens also on Fedora 23, as reported by rhn on irc.

comment:8 by zarac, 4 years ago

Same on Arch x86_64 Linux 4.12.8.

comment:9 by Neven Sajko, 6 months ago

Cc: Neven Sajko added

comment:10 by Neven Sajko, 6 months ago

There's more info that seems like it could be useful if someone tries to tackle this bug here: https://trac.ffmpeg.org/ticket/9199

In that case the last 15 seconds of audio are cut off (instead of just the last two), and pulseaudio isn't used, just ALSA directly.

There's also a large ffreport.log attached to that bug report (which is now closed as a duplicate).

Last edited 6 months ago by Neven Sajko (previous) (diff)
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