From 98cfadd648bfb2ab48e4c18d832e946a1ba050c8 Mon Sep 17 00:00:00 2001 From: Justin Ruggles Date: Fri, 21 Jan 2011 20:59:20 +0000 Subject: 10l: reverse the biquad coefficients. I did not notice that the filter implementation uses a reversed history state. Signed-off-by: Janne Grunau --- libavcodec/iirfilter.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'libavcodec/iirfilter.c') 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 -- cgit v1.2.3