From 91ccd38c0befb17d788c1621d1d4362dc1c40bd6 Mon Sep 17 00:00:00 2001 From: James Almer Date: Wed, 22 Mar 2017 12:28:58 -0300 Subject: avcodec/ac3dsp: add special-case handling for the C downmix_fixed function Reviewed-by: Michael Niedermayer Signed-off-by: James Almer --- libavcodec/ac3dsp.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) (limited to 'libavcodec') diff --git a/libavcodec/ac3dsp.c b/libavcodec/ac3dsp.c index 74f9e3caae..43438da131 100644 --- a/libavcodec/ac3dsp.c +++ b/libavcodec/ac3dsp.c @@ -279,6 +279,49 @@ static void ac3_downmix_c(float **samples, float **matrix, } } +static void ac3_downmix_5_to_2_symmetric_c_fixed(int32_t **samples, int16_t **matrix, + int len) +{ + int i; + int64_t v0, v1; + int16_t front_mix = matrix[0][0]; + int16_t center_mix = matrix[0][1]; + int16_t surround_mix = matrix[0][3]; + + for (i = 0; i < len; i++) { + v0 = (int64_t)samples[0][i] * front_mix + + (int64_t)samples[1][i] * center_mix + + (int64_t)samples[3][i] * surround_mix; + + v1 = (int64_t)samples[1][i] * center_mix + + (int64_t)samples[2][i] * front_mix + + (int64_t)samples[4][i] * surround_mix; + + samples[0][i] = (v0+2048)>>12; + samples[1][i] = (v1+2048)>>12; + } +} + +static void ac3_downmix_5_to_1_symmetric_c_fixed(int32_t **samples, int16_t **matrix, + int len) +{ + int i; + int64_t v0; + int16_t front_mix = matrix[0][0]; + int16_t center_mix = matrix[0][1]; + int16_t surround_mix = matrix[0][3]; + + for (i = 0; i < len; i++) { + v0 = (int64_t)samples[0][i] * front_mix + + (int64_t)samples[1][i] * center_mix + + (int64_t)samples[2][i] * front_mix + + (int64_t)samples[3][i] * surround_mix + + (int64_t)samples[4][i] * surround_mix; + + samples[0][i] = (v0+2048)>>12; + } +} + static void ac3_downmix_c_fixed(int32_t **samples, int16_t **matrix, int out_ch, int in_ch, int len) { @@ -307,6 +350,24 @@ static void ac3_downmix_c_fixed(int32_t **samples, int16_t **matrix, void ff_ac3dsp_downmix_fixed(AC3DSPContext *c, int32_t **samples, int16_t **matrix, int out_ch, int in_ch, int len) { + if (c->in_channels != in_ch || c->out_channels != out_ch) { + c->in_channels = in_ch; + c->out_channels = out_ch; + c->downmix_fixed = NULL; + + if (in_ch == 5 && out_ch == 2 && + !(matrix[1][0] | matrix[0][2] | + matrix[1][3] | matrix[0][4] | + (matrix[0][1] ^ matrix[1][1]) | + (matrix[0][0] ^ matrix[1][2]))) { + c->downmix_fixed = ac3_downmix_5_to_2_symmetric_c_fixed; + } else if (in_ch == 5 && out_ch == 1 && + matrix[0][0] == matrix[0][2] && + matrix[0][3] == matrix[0][4]) { + c->downmix_fixed = ac3_downmix_5_to_1_symmetric_c_fixed; + } + } + if (c->downmix_fixed) c->downmix_fixed(samples, matrix, len); else -- cgit v1.2.3