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| author | Justin Ruggles <justin.ruggles@gmail.com> | 2011-01-21 20:59:20 +0000 |
|---|---|---|
| committer | Michael Niedermayer <michaelni@gmx.at> | 2011-01-23 19:32:07 +0100 |
| commit | ff5eded449c32ef46489a9225445801837beb6a6 (patch) | |
| tree | ee51cd3ca8c6915e01bf0cf82ec7b3c0cc25f3df | |
| parent | ba0dd9e8ffed02a89ce5f0c5110cede6f07896ba (diff) | |
| download | ffmpeg-ff5eded449c32ef46489a9225445801837beb6a6.tar.gz | |
10l: reverse the biquad coefficients.
I did not notice that the filter implementation uses a reversed history state.
Signed-off-by: Janne Grunau <janne-ffmpeg@jannau.net>
(cherry picked from commit 98cfadd648bfb2ab48e4c18d832e946a1ba050c8)
| -rw-r--r-- | libavcodec/iirfilter.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/libavcodec/iirfilter.c b/libavcodec/iirfilter.c index 832559cfea..46b4973f85 100644 --- a/libavcodec/iirfilter.c +++ b/libavcodec/iirfilter.c @@ -137,15 +137,15 @@ static int biquad_init_coeffs(void *avc, struct FFIIRFilterCoeffs *c, if (filt_mode == FF_FILTER_MODE_HIGHPASS) { c->gain = ((1.0 + cos_w0) / 2.0) / a0; - x0 = (-(1.0 + cos_w0)) / a0; - x1 = ((1.0 + cos_w0) / 2.0) / a0; + x0 = ((1.0 + cos_w0) / 2.0) / a0; + x1 = (-(1.0 + cos_w0)) / a0; } else { // FF_FILTER_MODE_LOWPASS c->gain = ((1.0 - cos_w0) / 2.0) / a0; - x0 = (1.0 - cos_w0) / a0; - x1 = ((1.0 - cos_w0) / 2.0) / a0; + x0 = ((1.0 - cos_w0) / 2.0) / a0; + x1 = (1.0 - cos_w0) / a0; } - c->cy[0] = (2.0 * cos_w0) / a0; - c->cy[1] = (-1.0 + (sin_w0 / 2.0)) / a0; + c->cy[0] = (-1.0 + (sin_w0 / 2.0)) / a0; + c->cy[1] = (2.0 * cos_w0) / a0; // divide by gain to make the x coeffs integers. // during filtering, the delay state will include the gain multiplication |