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| author | Mathias Rauen <madshi@gmail.com> | 2013-01-05 11:30:31 -0500 |
|---|---|---|
| committer | Justin Ruggles <justin.ruggles@gmail.com> | 2013-01-20 14:20:47 -0500 |
| commit | 04ea5491a83e7d123faae5f9aff054838d95bbcb (patch) | |
| tree | 9a502425518f36e62ef37f2fabee838bdbf205ec /libavcodec | |
| parent | d9bf716945046333c24580d538f450b516f15710 (diff) | |
| download | ffmpeg-04ea5491a83e7d123faae5f9aff054838d95bbcb.tar.gz | |
ac3dec: fix non-optimal dithering of zero bit mantissas
Use a noise range of -0.707 to 0.707 instead of -0.5 to 0.5
Signed-off-by: Justin Ruggles <justin.ruggles@gmail.com>
Diffstat (limited to 'libavcodec')
| -rw-r--r-- | libavcodec/ac3dec.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/libavcodec/ac3dec.c b/libavcodec/ac3dec.c index 3c5147229f..82ae61857d 100644 --- a/libavcodec/ac3dec.c +++ b/libavcodec/ac3dec.c @@ -442,8 +442,9 @@ static void ac3_decode_transform_coeffs_ch(AC3DecodeContext *s, int ch_index, ma int mantissa; switch (bap) { case 0: + /* random noise with approximate range of -0.707 to 0.707 */ if (dither) - mantissa = (av_lfg_get(&s->dith_state) & 0x7FFFFF) - 0x400000; + mantissa = (av_lfg_get(&s->dith_state) / 362) - 5932275; else mantissa = 0; break; |