[Ffmpeg-devel] [RFC] smallcpy for h264

Siarhei Siamashka siarhei.siamashka
Sat Oct 7 10:56:51 CEST 2006

On Saturday 07 October 2006 05:11, Luca Barbato wrote:

> here a pretty dumb patch that happens to work nicely on my system,
> probably a better solution should be avoding memcpy.

ff_smallcpy_n in the patch assumes that size is divisible by 16, is it ok?

A small suggestion is to probably have no return type for these functions as
it is not used in ffmpeg anyway. It will make implementation a bit simplier
and faster (no need to save destination buffer address in a register or stack
for returning it later). Also an option for having direct calls instead of
function pointer calls would be good to have in order to reduce call overhead.

Nevertheless aligning buffers at 16 byte boundary is a good idea and having
some special redefineable functions to handle special buffer address
alignment/buffer size cases can help to improve performance on some
architectures (especially for those which require strict alignment).

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