[Ffmpeg-devel] H.264 encoder

[Michael Niedermayer]

Hi

On Thu, Oct 12, 2006 at 01:54:31PM +0200, Panagiotis Issaris wrote:
> Hi,
> 
> On Thu, Oct 12, 2006 at 11:49:13AM +0200, Michael Niedermayer wrote:
> > > [...]
> > > > > > probably not -> change pred_non_zero_count() so it takes the top and left
> > > > > > values as arguments instead of H264Context, or change it so a it takes a
> > > > > > pointer to non_zero_count_cache ...
> > > > > 
> > > > > Something like the attached patch does? Or should I drop the const and move left
> > > > > and top to the outer scope?
> > > > 
> > > > id move them out as the resulting code is simpler ...
> > > I've attached two patches, one moving them to the outermost scope (well, within
> > > the function) and one one scopelevel higher. Which one do you prefer (if any :)
> > > )
> > > ?
> > 
> > hmm, after reconsidering this, i think its best to forget sharing
> > pred_non_zero_count() between your encoder and h264.c the result looks
> > too messy :(
> I agree.
> 
> For sharing pred_motion() between h264.c and our encoder, I'm having similar
> problems: pred_motion() uses h->ref_cache[][] and mv_cache[][] which are being
> filled by the same fill_caches() which uses MpegEncContext.  Furthermore,
> pred_motion() calls fetch_diagonal_mv() which also uses h->ref_cache[][] and
> MpegEncContext. To be able to reuse it, I could do it in a similar way by
> changing the arguments of pred_motion() and fetch_diagonal_mv(), but that would
> give similar problems as in the pred_non_zero_count() case imho. I would have to
> put the following before every call to pred_motion() [1]:
>   const int index8= scan8[n];
>   const int top_ref=      h->ref_cache[list][ index8 - 8 ];
>   const int left_ref=     h->ref_cache[list][ index8 - 1 ];

what about changing your encoder to use a similar cache system?
would in improve speed? simplicity? 

[...]
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Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

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