[FFmpeg-devel] [PATCH] FFV1 rectangular slice multithreading

[Loren Merritt]

On Thu, 14 Oct 2010, Jason Garrett-Glaser wrote:

> Also while you're playing with FFV1, I mucked with the contexts a
> while back.  I was never able to get a very large improvement, but
> here's some of the ideas I tried:
>
> 1.  Base some (or all) of the contexts on previous residual values
> instead of neighboring pixels (it was almost equivalent in
> compression, but I'm curious how much a combination of that and the
> current approach could help).  The bonus of this method is you can
> combine it with FFV2's pixel ordering to allow decode/encode SIMD of
> the median prediction.

Using decoded neighbors is ok if the bitstream order is striped too. That 
also allows simd of context computations.

--Loren Merritt