/**
* Downmix the output to mono or stereo.
*/
-static void ac3_downmix(float samples[AC3_MAX_CHANNELS][256], int fbw_channels,
- int output_mode, float coef[AC3_MAX_CHANNELS][2])
+static void ac3_downmix(AC3DecodeContext *s)
{
int i, j;
float v0, v1, s0, s1;
for(i=0; i<256; i++) {
v0 = v1 = s0 = s1 = 0.0f;
- for(j=0; j<fbw_channels; j++) {
- v0 += samples[j][i] * coef[j][0];
- v1 += samples[j][i] * coef[j][1];
- s0 += coef[j][0];
- s1 += coef[j][1];
+ for(j=0; j<s->fbw_channels; j++) {
+ v0 += s->output[j][i] * s->downmix_coeffs[j][0];
+ v1 += s->output[j][i] * s->downmix_coeffs[j][1];
+ s0 += s->downmix_coeffs[j][0];
+ s1 += s->downmix_coeffs[j][1];
}
v0 /= s0;
v1 /= s1;
- if(output_mode == AC3_CHMODE_MONO) {
- samples[0][i] = (v0 + v1) * LEVEL_MINUS_3DB;
- } else if(output_mode == AC3_CHMODE_STEREO) {
- samples[0][i] = v0;
- samples[1][i] = v1;
+ if(s->output_mode == AC3_CHMODE_MONO) {
+ s->output[0][i] = (v0 + v1) * LEVEL_MINUS_3DB;
+ } else if(s->output_mode == AC3_CHMODE_STEREO) {
+ s->output[0][i] = v0;
+ s->output[1][i] = v1;
}
}
}
/* downmix output if needed */
if(s->channels != s->out_channels && !((s->output_mode & AC3_OUTPUT_LFEON) &&
s->fbw_channels == s->out_channels)) {
- ac3_downmix(s->output, s->fbw_channels, s->output_mode,
- s->downmix_coeffs);
+ ac3_downmix(s);
}
/* convert float to 16-bit integer */