[FFmpeg-devel] Touching base on first decoder ( CDXL ) before loosing direction

[Erion Omeri]

On Tue, Apr 7, 2009 at 3:31 PM, Michael Niedermayer <michaelni at gmx.at>wrote:

> On Tue, Apr 07, 2009 at 02:30:00PM -0500, Erion Omeri wrote:
> > Hello,
> >
> > I just wanted to check base with the team before I get off track.
> >
> > QUESTION: Am I in the right path to creating the CDXL codec (see files)?
>
> pretty much any not trivial contribution to ffmpeg is ok as
> qual task, ...
>
>
> >
> > I read the Wiki and the simple Cook decoder:
> > http://wiki.multimedia.cx/index.php?title=FFmpeg_codec_howto
> >
> >  I found the Pascal version of the CDXL decoder and have loosely tried to
> > convert it to C ( not done by any means). I did focus mainly on the READ
> > function.
> > I have made some generalizations and will have to make more as we go
> along.
> > http://aminet.net/package/gfx/show/AnimFX
> >
> >  I understand that there is not much time left to get this qualification
> > task up and running, so I will attach my files here so that you can see
> what
> > direction I am going. I have commented out a skeleton I grabbed from
> another
> > codec example and will eventually adapt my functions to using the FFMPEG
> > interface.
> >
>
> > I understand that in order to add a codec to the pool I will need to its
> ID
> > in a struct in AVCodec but if the order of that struct changes other
> > dependencies break. How do I go about adding my codec ID without breaking
> > the rest, should I just add it at the tail? On the other hand, I see
> > grouping in the struct which makes think it should go under video codecs
> > which is not at the tail.
>
> how to add a value into a enum without changing the existing values and
> still do it close to a semantically nice spot is basic C knowledge which
> is a prerequestite for as sucessfull gsoc ffmpeg project
>


Nice, pardon the ADD there.
I see that you guys are moving up with ranges.
I will go ahead an add CODEC_ID_CDXL following CODEC_ID_AURA2,
which should keep everything in the range since we are still below  0x10000.

Thanks for the hints Mike



>
> >
> > I would also need to make an addition on the Make file to link my cdxl.o
> and
> > its dependencies to the rest.
> >
> > Do you guys have a procedure to test make your codecs while programming
> > without the overwhelming verbose and time consuming make?
>
> "make test" will test the existing stuff
> and "ffplay some_cdxl_file" will test your newly added code
>
> >
> > Also how much time is allowed to complete the qualification tasks?
>
> until google freezes the choice of the accepted applications, also
> keep in mind that code must pass review and this needs many iterations
> that is
> you submit patch -> we review -> it passed review -> we change the choosen
> apps must happen prior to googles deadline.
>
> also you should read our developers guide
>
> [...]
> --
> Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
>
> it is not once nor twice but times without number that the same ideas make
> their appearance in the world. -- Aristotle
>
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