[FFmpeg-soc] [soc]: r704 - dirac/libavcodec/dirac.c

Marco Gerards mgerards at xs4all.nl
Sun Aug 12 12:16:25 CEST 2007


Michael Niedermayer <michaelni at gmx.at> writes:

[...]

> performing lifting pass X over the whole image and then pass X+1 over the
> whole image is not very cache friendly
> it would be better to perform lifting pass X for a line then pass X+1 for
> whatever line(s) it can be performed with the data which became available
> and then do pass X for the next line, ...
>
> also look at snow.c::lift() maybe something like that could be used to
> simplify the code

Yes, I will try to look into this.

Will it be possible to share code between Dirac, JPEG2000 and Snow
after SoC?  Dirac uses the (9,7) and (5,3) wavelets by default.

Other wavelets it supports are (13,5), Haar (no shift), Haar (shift
per level), Haar (double shift per level), Fidelity Filter and (9,5).
I really hope code can be shared after SoC so this can be optimized.

The same is true for OBMC.  Next week I want to start looking into the
encoder.  Would it be easy to use your code from Snow, or would it be
that different that a new implementation is required?

--
Marco




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