attempt to retain samples in mlt_frame_mix_audio, make consumers request the number...

[melted] / mlt / src / framework / mlt_frame.c

diff --git a/mlt/src/framework/mlt_frame.c b/mlt/src/framework/mlt_frame.c
index 5a5701a..3b11fcf 100644 (file)
--- a/mlt/src/framework/mlt_frame.c
+++ b/mlt/src/framework/mlt_frame.c
@@ -239,17 +239,20 @@ int mlt_frame_get_audio( mlt_frame this, int16_t **buffer, mlt_audio_format *for
        }
        else
        {
+               if ( *samples <= 0 )
+                       *samples = 1920;
+               if ( *channels <= 0 )
+                       *channels = 2;
+               if ( *frequency <= 0 )
+                       *frequency = 48000;
                if ( test_card.afmt != *format )
                {
                        test_card.afmt = *format;
-                       test_card.audio = realloc( test_card.audio, 1920 * 2 * sizeof( int16_t ) );
-                       memset( test_card.audio, 0, 1920 * 2 * sizeof( int16_t ) );
+                       test_card.audio = realloc( test_card.audio, *samples * *channels * sizeof( int16_t ) );
+                       memset( test_card.audio, 0, *samples * *channels * sizeof( int16_t ) );
                }
                
                *buffer = test_card.audio;
-               *frequency = 48000;
-               *channels = 2;
-               *samples = 1920;
        }
        return 0;
 }
@@ -692,6 +695,9 @@ int mlt_frame_mix_audio( mlt_frame this, mlt_frame that, float weight, int16_t *
 {
        int ret = 0;
        int16_t *p_src, *p_dest;
+       int16_t *src, *dest;
+       static int16_t *extra_src = NULL, *extra_dest = NULL;
+       static int extra_src_samples = 0, extra_dest_samples = 0;
        int frequency_src, frequency_dest;
        int channels_src, channels_dest;
        int samples_src, samples_dest;
@@ -699,20 +705,86 @@ int mlt_frame_mix_audio( mlt_frame this, mlt_frame that, float weight, int16_t *
 
        mlt_frame_get_audio( this, &p_dest, format, &frequency_dest, &channels_dest, &samples_dest );
        mlt_frame_get_audio( that, &p_src, format, &frequency_src, &channels_src, &samples_src );
+       //fprintf( stderr, "frame dest samples %d channels %d\n", samples_dest, channels_dest );
+       //fprintf( stderr, "frame src  samples %d channels %d\n", samples_src, channels_src );
+       
 
-       *samples = samples_src < samples_dest ? samples_src : samples_dest;
+#if 0
+       // Append new samples to leftovers
+       if ( extra_dest_samples > 0 )
+       {
+               fprintf( stderr, "prepending %d samples to dest\n", extra_dest_samples );
+               dest = realloc( extra_dest, ( samples_dest + extra_dest_samples ) * 2 * channels_dest );
+               memcpy( &extra_dest[ extra_dest_samples * channels_dest ], p_dest, samples_dest * 2 * channels_dest );
+       }
+       else
+               dest = p_dest;
+       if ( extra_src_samples > 0 )
+       {
+               fprintf( stderr, "prepending %d samples to src\n", extra_src_samples );
+               src = realloc( extra_src, ( samples_src + extra_src_samples ) * 2 * channels_src );
+               memcpy( &extra_src[ extra_src_samples * channels_src ], p_src, samples_src * 2 * channels_src );
+       }
+       else
+               src = p_src;
+#else
+       src = p_src;
+       dest = p_dest;
+#endif
+
+       // determine number of samples to process       
+       if ( samples_src + extra_src_samples < samples_dest + extra_dest_samples )
+               *samples = samples_src + extra_src_samples;
+       else if ( samples_dest + extra_dest_samples < samples_src + extra_src_samples )
+               *samples = samples_dest + extra_dest_samples;
+       
        *channels = channels_src < channels_dest ? channels_src : channels_dest;
        *buffer = p_dest;
 
+       // Mixdown
        for ( i = 0; i < *samples; i++ )
        {
                for ( j = 0; j < *channels; j++ )
                {
-                       double dest = (double) p_dest[ i * channels_dest + j ];
-                       double src = (double) p_src[ i * channels_src + j ];
-                       p_dest[ i * channels_dest + j ] = src * weight + dest * ( 1.0 - weight );
+                       double d = (double) dest[ i * channels_dest + j ];
+                       double s = (double) src[ i * channels_src + j ];
+                       dest[ i * channels_dest + j ] = s * weight + d * ( 1.0 - weight );
                }
        }
+
+       // We have to copy --sigh
+       if ( dest != p_dest )
+               memcpy( p_dest, dest, *samples * 2 * *channels );
+
+#if 0
+       // Store the leftovers
+       if ( samples_src + extra_src_samples < samples_dest + extra_dest_samples )
+       {
+               extra_dest_samples = ( samples_dest + extra_dest_samples ) - ( samples_src + extra_src_samples );
+               size_t size = extra_dest_samples * 2 * channels_dest;
+               fprintf( stderr, "storing %d samples from dest\n", extra_dest_samples );
+               if ( extra_dest )
+                       free( extra_dest );
+               extra_dest = malloc( size );
+               if ( extra_dest )
+                       memcpy( extra_dest, &p_dest[ ( samples_dest - extra_dest_samples - 1 ) * channels_dest ], size );
+               else
+                       extra_dest_samples = 0;
+       }
+       else if ( samples_dest + extra_dest_samples < samples_src + extra_src_samples )
+       {
+               extra_src_samples = ( samples_src + extra_src_samples ) - ( samples_dest + extra_dest_samples );
+               size_t size = extra_src_samples * 2 * channels_src;
+               fprintf( stderr, "storing %d samples from src\n", extra_dest_samples );
+               if ( extra_src )
+                       free( extra_src );
+               extra_src = malloc( size );
+               if ( extra_src )
+                       memcpy( extra_src, &p_src[ ( samples_src - extra_src_samples - 1 ) * channels_src ], size );
+               else
+                       extra_src_samples = 0;
+       }
+#endif
        
        return ret;
 }