[FFmpeg-devel] [PATCH 2/3] libavcodec: ac3 floating point decoder fixes

[Reimar Döffinger]

On Wed, Nov 28, 2012 at 02:51:57PM +0000, Babic, Nedeljko wrote:
> All the channels are used, they are just mixed in downmix.

Yes, but since the code downmixes them before imdct your change means
that in some cases (far) more transforms will be done that necessary.

> Handling of blocks with different length in downmix is erroneous in current code and can cause incorrect
> decoding and our patch is fixing this.

I have no clue about AC3 but I suspect this can be solved by adding a
condition to not use this optimization in that special case.