[FFmpeg-devel] [PATCH] flv set pts

Michael Niedermayer michaelni
Tue Sep 30 20:55:25 CEST 2008

On Tue, Sep 30, 2008 at 11:28:45AM -0700, Baptiste Coudurier wrote:
> Hi,
> Michael Niedermayer wrote:
> > On Mon, Sep 29, 2008 at 07:56:17PM -0700, Baptiste Coudurier wrote:
> >> Baptiste Coudurier wrote:
> >>> Hi,
> >>>
> >>> $subject.
> >>>
> >> Scratch old patch, this one should be correct.
> > 
> > can you post some example input&output pts & dts values for some file
> > with b frames.
> > I suspicion would be that the patch is not completely correct but this
> > should be more obvious from a list of timestamps and frame types.
> > 
> Well, I didn't find any having < 0 cts yet, however it has been said
> that cts is signed like in .mov, so code is assuming that.
> Files generated by FFmpeg does not have < 0 cts.
> Patch is doing the same as the .mov demuxer excepts that we cannot know
> in advance while we can in .mov, though it misses has_b_frames = 1, I
> can see, not harmful though.
> What do you think could be wrong ? I'll try to find a file in the mean time.

if we take as example normal mpeg2 style IPB then
dts:    0123456
pts:    1423756
would be correct

now if dts where increased by one:

dts:    1234567
pts:    1423756

then this would be wrong, and not only the ones for the B frames
would be wrong but all would be. That is for example if the I frame
is feeded at time 1 into the decoder then it will be output at time 2 not 1.


Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Freedom in capitalist society always remains about the same as it was in
ancient Greek republics: Freedom for slave owners. -- Vladimir Lenin
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: Digital signature
URL: <http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/attachments/20080930/c5e22569/attachment.pgp>

More information about the ffmpeg-devel mailing list