[FFmpeg-devel] [PATCH] Optimize QTRLE encoding

Malcolm Bechard malcolm.bechard at gmail.com
Wed Feb 13 03:34:44 CET 2013

On Tue, Feb 12, 2013 at 2:47 PM, Alexis Ballier <alexis.ballier at gmail.com>wrote:

> +
> +    pixel_size = s->pixel_size;
> +
> this (and related changes s->pixel_size -> pixel_size): does it have
> any performance impact alone ? compiler should be able to optimize it
> but some hint may not hurt.
> IMHO this should be a separate patch so that it eases reviewing the
> non-trivial part of the patch
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I don't think we can assume all compilers will optimize that. The fact that
this code runs 2x-3x faster when compiled with VS2010 vs. gcc shows how
much optimization can be missed (although I'm hoping it's something I'm
doing wrong with the gcc compile).
The goal of the patch is to speed up that loop so while it may be a small
or even immeasurable speedup I think it's valid portion of the work without
adding any complexity to the code.

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