[FFmpeg-trac] #5900(undetermined:new): alsa/pulse grab cuts last 2 seconds of audio

FFmpeg trac at avcodec.org
Thu Oct 20 14:23:56 EEST 2016


#5900: alsa/pulse grab cuts last 2 seconds of audio
-------------------------------------+-------------------------------------
             Reporter:  tsg1zzn      |                     Type:  defect
               Status:  new          |                 Priority:  normal
            Component:               |                  Version:
  undetermined                       |  unspecified
             Keywords:  screencast,  |               Blocked By:
  sound                              |  Reproduced by developer:  0
             Blocking:               |
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
 Summary of the bug:
 I have spent probably 10 hours trying to record the screen _losslessly_ in
 linux, and I simply cannot get it to work.

 The commandline in the wiki for this is wrong, it does a lossy conversion
 rgb->yuv. Someone should note this and give a lossless option.

 Currently I am pretty close, but the sound cuts 2 seconds before the end
 of the recorded file.

 How to reproduce:
 {{{
 $ ffmpeg -thread_queue_size 2048 -f alsa -i pulse -f x11grab -s 1280x720
 -i :0 -acodec libvorbis -ab 256k  -vcodec libx264rgb -r 30 -pix_fmt rgb24
 "file $(date --rfc-3339=seconds).mkv" -report

 ^C
 }}}

 ffprobe shows the video stream and audio stream durations resp. like this:
 DURATION        : 00:00:07.103000000
 DURATION        : 00:00:05.399000000

 Attached: ffmpeg -report
 Attached: ffprobe output

--
Ticket URL: <https://trac.ffmpeg.org/ticket/5900>
FFmpeg <https://ffmpeg.org>
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