[FFmpeg-devel] [PATCH] av_get_delay
michaelni at gmx.at
Thu Jun 30 17:11:23 CEST 2011
On Thu, Jun 30, 2011 at 04:40:14PM +0200, Michael Niedermayer wrote:
> On Thu, Jun 30, 2011 at 10:17:52AM -0400, Mike Scheutzow wrote:
> > Michael Niedermayer wrote:
> >> On Thu, Jun 30, 2011 at 09:22:04AM -0400, Mike Scheutzow wrote:
> >>> Michael Niedermayer wrote:
> >>>>>> This doesnt seem to work very well for example when you have:
> >>>>>> a slideshow with commentary, the delay from the video stream could
> >>>>>> make quite big jumps an be constant between them. It might be
> >>>>>> better to add the remaining duration of the currently displayed frame
> >>>>>> in there or something
> >>> This is a very different use case than the original proposal was
> >>> meant to solve, which I understood as pre-skewing uncompressed
> >>> output samples to improve lip sync.
> >> you seem to missunderstand this somehow.
> > Well, it seems that you do not understand the problem that Nicolas is
> > trying to improve. Do you agree with these statements:
> you replied to a comment i made that was about a poorly worded doxy
> comment. Nicolas has already corrected the doxy and i just wanted to
> point out that it appeared to me you misunderstood my comment as
> something else.
> > 1) We are talking about presentation (display to the user of audio and
> > video.)
> > 2) There is a system delay between the call to snd_write_pcm() and when
> > the user actually hears that sound. Assume that this delay is constant,
> > +- half write size.
> > 3) This is a (possibly different) system delay between the call to pass
> > video pixels to the video subsystem, and when the user can see that
> > frame of data. Assume this delay is constant, +- half frame.
also 2 & 3 are not so simple in reality and far from constant
Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
I am the wisest man alive, for I know one thing, and that is that I know
nothing. -- Socrates
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Size: 198 bytes
Desc: Digital signature
More information about the ffmpeg-devel