[Ffmpeg-devel] Help understanding AVParser

[Cool_Zer0]

On 12/20/06, Michael Niedermayer <michaelni at gmx.at> wrote:
>
> Hi
>
> On Wed, Dec 20, 2006 at 12:01:24PM +0000, Cool_Zer0 wrote:
> [...]
> > >[...]
> > >> I've tried other combinations like
> > >> $ ffmpeg -i -vcodec h263 compressed.avi -vcodec mpeg1video tt.mpg
> > >
> > >this is of course meaningless nonsese what you want is
> > >ffmpeg -f h263 -i compressed.avi ...
> >
> >
> >
> > Now it works but with the same problems...
> > I'm putting the file in attachment (it's only 121kb) for you to see.
> >
> > >>From now on I'm totally stucked... I can't understand what the problem
> is
> > >>:(
> >
> > At the end of this mail is the result of the ffmpeg conversion... It
> gives
> > some errors... (May be that's the problem!!)...
> >
> >
> > [...]
> > >> But any have worked...
> > >> :(
> > >>
> > >> We must be really dumb... I have three more people working in this
> > >project
> > >
> > >yes, and to help others who have the same problem ... maybe you want to
> > >suggest some improvements to the docs after you figured out where the
> > >problem
> > >was ...
> >
> >
> >
> > It will be my pleasure. And it will help me improve my english :)
> >
> >
> > also dont mix packets from unrelated streams like sending audio packets
> to
> > >the video decoder and dont forget to parse and strip any RTP headers or
> > >what
> > >else non-h263 is there (iam just guessing, these could cause such
> errors)
> >
> >
> >
> > Nop... I'm only saving H.263 packets... I even have use a hexadecimal
> > display to show what I've saved and what I've received (with the help of
> > Ethereal)...
>
> i suggest you try:
>
> ffmpeg -i somefileofyourchoice -f image2 -vcodec h263 -s 176x144
> frame%d.h263
>
> this will provide you with plenty of valid h263 frames for comparission



Great!!!
I split an .avi file into 12 h263 frames... When I concatenate them and
then, using ffmpeg, compressed them to mpeg1video and use ffplay to play the
resulting movie it all works fine. But when I put the raw RGB frames on
Paint Shop Pro they aren't much good :( Besides that, a lot of frames are
missing...

So... I think I have 2 problems:
- FFMpeg is not recognizing my H.263 RTP Payload header (RFC2190)
- Something is wrong on my code because I'm losing a lot of frames...

Michael, do you know any util that let's me see the header (or the format)
of the H.263 frames that I generate with ffmpeg (using the command that you
gave to me)? I just need to see what is ffmpeg expecting...


Thanks once more

[...]