[FFmpeg-devel] [PATCH] FFplay speedup if stepping whilst paused

[Craig Nicol]

On 8/2/07, Michael Niedermayer <michaelni at gmx.at> wrote:
> Hi
>
> On Thu, Aug 02, 2007 at 11:39:52AM +0100, Craig Nicol wrote:
> > I've been writing a drift-correction program based on ffplay.c, but I've
> > discovered a problem in the original ffplay code that is still in the latest
> > SVN I've only tested this under Windows (MinGW), but given the patch that
> > fixes it below, I assume this is common to all platforms. The problem should
> > be repeatable by:
> >
> > 1. Open a video file in ffplay (I've used MPEG and an AVI recorded from
> > SecondLife)
> > 2. Pause the playing video by pressing space (or press s, which also causes
> > a pause)
> > 3. Step forward a frame by pressing s
> > 4. Wait a few seconds
> > 5. Unpause the video by pressing space
> >
> > Expected Behaviour:
> > Video should continue at normal speed.
> >
> > Actual Behaviour:
> > Video speeds up to catch-up with the 'lost' few seconds.
> >
> > The audio stream appears to pause and restart correctly. I have not tested
> > this on videos with subtitles.
> >
> > Patch behaviour:
> > Uses the existing stream_pause() function within the step frame code to
> > maintain the correct state whether paused using 's' or the space key.
> >
> > Suggested commit message:
> > Corrected pause handling when using the 's' step by frame key.
> > --
> > skype: callto:craignicol     sip:craignicol at ekiga.net
>
> > Index: ffplay.c
> > ===================================================================
> > --- ffplay.c  (revision 9868)
> > +++ ffplay.c  (working copy)
> > @@ -2213,7 +2213,7 @@
> >  {
> >      if (cur_stream) {
> >          if (cur_stream->paused)
> > -            cur_stream->paused=0;
> > +            stream_pause(cur_stream);
> >          cur_stream->video_current_pts = get_video_clock(cur_stream);
>
> shouldnt the
> cur_stream->video_current_pts=  ...
> be removed ?
>
I didn't remove it in the code I'm working with, and it works
properly. What behaviour would you expect to change if that line was
removed?

Regards,
Craig.


-- 
skype: callto:craignicol     sip:craignicol at ekiga.net