ffplay freezes with date -s in linux

[sahandeva]

While playing a video clip in ffplay, setting system time in linux by "date -s" freezes video playback while audio seems to be playing.

System Ubuntu 10.04 LTS x86_64
ffmpeg recent (20/50/2011) git pulled

Does it has some thing to do with core ffmpeg

[Carl Eugen Hoyos]

Video stops playing (esp, if the time is set back), but I cannot reproduce a freeze.

[sahandeva]

Replying to cehoyos:

Video stops playing (esp, if the time is set back), but I cannot reproduce a freeze.

Yes video stops playing but the audio does continue to play.

Wondering weather this is localized to ffplay implementation of PTS - DTS bounded to system clock or ffmpeg specific.

Checked the same scenario with VLC which perfectly plays video + audio irrespective of the system time modifications.

Please shed some light on this as implementation of my case require system time modification (using NTP)to be not effective on ffmpeg playback.

[Stefano Sabatini]

This is related to the implementation of av_gettime(void) in libavformat.

Read also the thread:
​http://thread.gmane.org/gmane.comp.video.ffmpeg.devel/101431/focus=101434

Work in this area is very welcome.

[Stefano Sabatini]

Increased priority level to "normal", indeed this is not only a bug in ffplay but a defect in libavformat.

[Michael Niedermayer]

Do we want to do thread locking in av_gettime() ? if so that shouldnt be hard to workaround

[sahandeva]

Replying to michael:

Do we want to do thread locking in av_gettime() ? if so that shouldnt be hard to workaround

I didn't get you.

Is this have some thing to do with way I use libavformat. Please elaborate as I m not well versed.

[Marton Balint]

I guess this is fixed with the latest av_gettime_relative patches in commit 0ca0b4c29cf750cbb15732cddbe16723a66afda8.