[FFmpeg-devel] [PATCH] WMA Voice decoder

Ronald S. Bultje rsbultje
Wed Feb 10 19:41:47 CET 2010


On Wed, Feb 10, 2010 at 1:30 PM, Reimar D?ffinger
<Reimar.Doeffinger at gmx.de> wrote:
[discussion about frame_desc]
> You're right it's no real issue with bitfields assuming you don't mind the other
> issues like
> 1) gcc possibly generating code for accessing it that is even more inefficient
> than you can possibly imagine
> 2) incompatibility between compilers (should be no issue here)
> 3) I don't trust gcc to have sufficient test cases for bitstream handling.
> Anyway this is way beyond bikeshed already, just using 4 bytes for such
> small values is maybe going a bit too far.

I figure in the end that it's not used that much (we access that field
maybe 5 times per frame or so, depending on the amount of
blocks/frame), so how well (or not) gcc's generated code performs,
isn't all too relevant in this particular case. The other pieces of
code that you and Vitor pointed out (particularly aw_pulse_set1/2())
are much more performance-critical.

I'll keep it as-is for now, let's get the patch in.


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