support for dynamic 2.0/5.1 AC3 changes - bug#3441

diff --git a/ac3dec/libac3/downmix.c b/ac3dec/libac3/downmix.c
index 6d42342d82e72f8d7cd2ecc89c5918200b6ab423..18271f1feb842512027112d33e995eff4b23d1af 100644 (file)
--- a/ac3dec/libac3/downmix.c
+++ b/ac3dec/libac3/downmix.c
@@ -251,7 +251,23 @@ downmix_3f_0r_to_2ch(bsi_t* bsi, stream_samples_t samples,sint_16 *s16_samples)
                s16_samples[j * 2 + 1] = (sint_16) (right_tmp * 32767.0f);
        }
 }
-                               
+
+static void
+downmix_2f_0r_to_6ch(bsi_t* bsi, stream_samples_t samples,sint_16 *s16_samples)
+{
+       uint_32 j;
+       float *left = 0, *right = 0;
+
+       left      = samples[0];
+       right     = samples[1];
+
+       for (j = 0; j < 256; j++) 
+       {
+               s16_samples[j * 6 ]    = (sint_16) (*left++  * 32767.0f);
+               s16_samples[j * 6 + 1] = (sint_16) (*right++ * 32767.0f);
+       } //FIXME enable output on surround channels, too.
+}
+
 static void
 downmix_2f_0r_to_2ch(bsi_t* bsi, stream_samples_t samples,sint_16 *s16_samples)
 {
@@ -368,13 +384,19 @@ void downmix(bsi_t* bsi, stream_samples_t samples,sint_16 *s16_samples)
                        downmix_3f_0r_to_2ch(bsi,samples,s16_samples);
                break;
 
-               // 2/0
+               // 2/0 - 2f_0r_to_6ch not really, but allows -D pcm.surround51:1 with 2/0 and 3/2 input (VDR e.g.)
                case 2:
-                       if (ac3_config.num_output_ch != 2) {
+                       switch (ac3_config.num_output_ch) {
+                       case 2:
+                               downmix_2f_0r_to_2ch(bsi,samples,s16_samples);
+                               break;
+                       case 6:
+                               downmix_2f_0r_to_6ch(bsi,samples,s16_samples);
+                               break;
+                       default:
                                fprintf(stderr,"unsupported 2/0 channels %d\n", ac3_config.num_output_ch);
                                exit(1);
                        }
-                       downmix_2f_0r_to_2ch(bsi,samples,s16_samples);
                break;
 
                // 1/0