avcodec/ac3dsp: add special-case handling for the C downmix_fixed function

Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: James Almer <jamrial@gmail.com>
This commit is contained in:
James Almer 2017-03-22 12:28:58 -03:00
parent 53f1d6a8ee
commit 91ccd38c0b

View File

@ -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