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| author | Justin <justin.ruggles@gmail.com> | 2011-03-11 13:03:26 -0500 |
|---|---|---|
| committer | Justin Ruggles <justin.ruggles@gmail.com> | 2011-03-14 08:45:26 -0400 |
| commit | 323e6fead07c75f418e4b60704a4f437bb3483b2 (patch) | |
| tree | 14e0886587813468e232931cc8cee782b205b44a /libavcodec/ac3enc_fixed.h | |
| parent | 6e7cf13b6b1d0e08969b64129b9022cc1171d875 (diff) | |
| download | ffmpeg-323e6fead07c75f418e4b60704a4f437bb3483b2.tar.gz | |
ac3enc: do not right-shift fixed-point coefficients in the final MDCT stage.
This increases the accuracy of coefficients, leading to improved quality.
Rescaling of the coefficients to full 25-bit accuracy is done rather than
offsetting the exponent values. This requires coefficient scaling to be done
before determining the rematrixing strategy. Also, the rematrixing strategy
calculation must use 64-bit math to prevent overflow due to the higher
precision coefficients.
Diffstat (limited to 'libavcodec/ac3enc_fixed.h')
| -rw-r--r-- | libavcodec/ac3enc_fixed.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/libavcodec/ac3enc_fixed.h b/libavcodec/ac3enc_fixed.h index 12c8ace4aa..bad2306321 100644 --- a/libavcodec/ac3enc_fixed.h +++ b/libavcodec/ac3enc_fixed.h @@ -36,6 +36,8 @@ typedef int16_t SampleType; typedef int32_t CoefType; typedef int64_t CoefSumType; +#define MAC_COEF(d,a,b) MAC64(d,a,b) + /** * Compex number. |