libhb: Allow control of audio mix normalization

Since switching to libavresample for audio mixing, our output
volume levels have been reduced because libavresample
does mix level normalization by default.  This change
applies a patch to libav to allow us to disable this behavior
and adds a new field to hb_audio_config_t to allow the
hb frontends to control this feature.


git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@4884 b64f7644-9d1e-0410-96f1-a4d463321fa5

1 files changed, 48 insertions, 0 deletions

diff --git a/test/test.c b/test/test.c
index 5d61b579c..b59534d44 100644
--- a/test/test.c
+++ b/test/test.c
@@ -71,6 +71,7 @@ static int    allowed_audio_copy = -1;
 static char * mixdowns    = NULL;
 static char * dynamic_range_compression = NULL;
 static char * audio_gain  = NULL;
+static char ** normalize_mix_level  = NULL;
 static char * atracks     = NULL;
 static char * arates      = NULL;
 static char ** abitrates  = NULL;
@@ -2096,6 +2097,41 @@ static int HandleEvents( hb_handle_t * h )
             }
             /* Audio Gain */
 
+            /* Audio Mix Normalization */
+            i = 0;
+            int norm = 0;
+            if( normalize_mix_level )
+            {
+                for ( i = 0; normalize_mix_level[i] != NULL && i < num_audio_tracks; i++ )
+                {
+                    char * token = normalize_mix_level[i];
+                    norm = atoi(token);
+                    audio = hb_list_audio_config_item(job->list_audio, i);
+
+                    if( audio != NULL )
+                    {
+                        audio->out.normalize_mix_level = norm;
+                    }
+                    else
+                    {
+                        fprintf(stderr, "Ignoring normalization %d, no audio tracks\n", norm);
+                    }
+                }
+            }
+            if (i < num_audio_tracks && i == 1)
+            {
+                /* We have fewer inputs than audio tracks,
+                 * and we only have one input, use
+                 * that for all tracks.
+                 */
+                for (; i < num_audio_tracks; i++)
+                {
+                    audio = hb_list_audio_config_item(job->list_audio, i);
+                    audio->out.normalize_mix_level = norm;
+                }
+            }
+            /* Audio Mix Normalization */
+
             /* Audio Track Names */
             if ( anames )
             {
@@ -2883,6 +2919,10 @@ static void ShowHelp()
     "                            Separated by commas for more than one audio track.\n"
     "                            (mono/stereo/dpl1/dpl2/6ch, default: up to 6ch for ac3,\n"
     "                            up to dpl2 for other encoders)\n"
+    "        --normalize-mix     Normalize audio mix levels to prevent clipping.\n"
+    "               <string>     Separated by commas for more than one audio track.\n"
+    "                            0 = Disable Normalization (default)\n"
+    "                            1 = Enable Normalization\n"
     "    -R, --arate             Set audio samplerate(s) (" );
     for( i = 0; i < hb_audio_rates_count; i++ )
     {
@@ -3186,6 +3226,7 @@ static int ParseOptions( int argc, char ** argv )
     #define X264_PRESET         284
     #define X264_TUNE           285
     #define H264_LEVEL          286
+    #define NORMALIZE_MIX       287
     
     for( ;; )
     {
@@ -3212,6 +3253,7 @@ static int ParseOptions( int argc, char ** argv )
             { "markers",     optional_argument, NULL,    'm' },
             { "audio",       required_argument, NULL,    'a' },
             { "mixdown",     required_argument, NULL,    '6' },
+            { "normalize-mix", required_argument, NULL,  NORMALIZE_MIX },
             { "drc",         required_argument, NULL,    'D' },
             { "gain",        required_argument, NULL,    AUDIO_GAIN },
             { "subtitle",    required_argument, NULL,    's' },
@@ -3430,6 +3472,12 @@ static int ParseOptions( int argc, char ** argv )
                     audio_gain = strdup( optarg );
                 }
                 break;
+            case NORMALIZE_MIX:
+                if( optarg != NULL )
+                {
+                    normalize_mix_level = str_split( optarg, ',' );
+                }
+                break;
             case 's':
                 subtracks = str_split( optarg, ',' );
                 break;