[FFmpeg-devel] [PATCH 2/3] ac3enc: shift coefficients to 24-bit following MDCT rather than using an exponent offset.
Wed Mar 9 23:38:34 CET 2011
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).
More information about the ffmpeg-devel