[FFmpeg-devel] [PATCH] AAC: optimise bitstream reading in decode_spectrum_and_dequant()

Måns Rullgård mans
Fri Jan 15 13:41:44 CET 2010


Robert Swain <robert.swain at gmail.com> writes:

> On 15/01/10 05:10, Mans Rullgard wrote:
>> Using the low-level macros directly avoids redundant open/update/close
>> cycles.
>>
>> 2-3% faster on ARM, PPC, and Core i7.
>
> Nice! Keep them coming. :)
>
>> ---
>>   libavcodec/aac.c |   93 +++++++++++++++++++++++++++++++++++++----------------
>>   1 files changed, 65 insertions(+), 28 deletions(-)
>>
>> diff --git a/libavcodec/aac.c b/libavcodec/aac.c
>> index 393f2e6..0fbab77 100644
>> --- a/libavcodec/aac.c
>> +++ b/libavcodec/aac.c
>
> [...]
>
>> -                            const int index = get_vlc2(gb, vlc_tab, 8, 2);
>> +                            int code;
>
> My only comment is that this variable rename seems unrelated. Apply
> that change separately in my opinion.

The GET_VLC macro declares a temp variable called index, so it has to
be renamed.

-- 
M?ns Rullg?rd
mans at mansr.com



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