[FFmpeg-devel] [PATCH 2/3] ac3enc: shift coefficients to 24-bit following MDCT rather than using an exponent offset.

[Justin Ruggles]

On 03/09/2011 04:48 PM, M?ns Rullg?rd wrote:

> Justin Ruggles <justin.ruggles at gmail.com> writes:
> 
>> This makes channel coupling more accurate, increasing quality for stereo
>> content.  It also simplifies exponent extraction and mantissa quantization
>> by no longer needing to apply an offset to the exponents.
>> ---
>>  libavcodec/ac3enc.c        |   13 ++++++-------
>>  libavcodec/ac3enc_fixed.c  |   42 ++++++++++++++++++++++++++++++++++--------
>>  tests/ref/acodec/ac3_fixed |    2 +-
>>  3 files changed, 41 insertions(+), 16 deletions(-)
> 
> Looks OK.


Please hold off on applying this patch and #3 to git.ffmpeg.org.

I have another patch which will only need right shifting for the
coefficient scaling and gets better quality (and likely better speed,
but I haven't done benchmarks yet).

-Justin