audio mix and repeated frames

[melted] / src / modules / core / transition_mix.c

diff --git a/src/modules/core/transition_mix.c b/src/modules/core/transition_mix.c
index fda1d1a..1f08471 100644 (file)
--- a/src/modules/core/transition_mix.c
+++ b/src/modules/core/transition_mix.c
@@ -34,7 +34,7 @@ static int transition_get_audio( mlt_frame frame, int16_t **buffer, mlt_audio_fo
        mlt_properties a_props = mlt_frame_properties( frame );
 
        // Get the b frame from the stack
-       mlt_frame b_frame = mlt_frame_pop_frame( frame );
+       mlt_frame b_frame = mlt_frame_pop_audio( frame );
 
        // Get the properties of the b frame
        mlt_properties b_props = mlt_frame_properties( b_frame );
@@ -42,13 +42,19 @@ static int transition_get_audio( mlt_frame frame, int16_t **buffer, mlt_audio_fo
        // Restore the original get_audio
        frame->get_audio = mlt_properties_get_data( a_props, "mix.get_audio", NULL );
 
-       double mix = 0.5;
+       double mix_start = 0.5, mix_end = 0.5;
+       if ( mlt_properties_get( b_props, "audio.previous_mix" ) != NULL )
+               mix_start = mlt_properties_get_double( b_props, "audio.previous_mix" );
        if ( mlt_properties_get( b_props, "audio.mix" ) != NULL )
-               mix = mlt_properties_get_double( b_props, "audio.mix" );
-       mlt_frame_mix_audio( frame, b_frame, mix, buffer, format, frequency, channels, samples );
+               mix_end = mlt_properties_get_double( b_props, "audio.mix" );
+       if ( mlt_properties_get_int( b_props, "audio.reverse" ) )
+       {
+               mix_start = 1 - mix_start;
+               mix_end = 1 - mix_end;
+       }
+       //fprintf( stderr, "transition_mix: previous %f current %f\n", mix_start, mix_end );
 
-       // Push the b_frame back on for get_image
-       mlt_frame_push_frame( frame, b_frame );
+       mlt_frame_mix_audio( frame, b_frame, mix_start, mix_end, buffer, format, frequency, channels, samples );
 
        return 0;
 }
@@ -63,29 +69,58 @@ static mlt_frame transition_process( mlt_transition this, mlt_frame a_frame, mlt
        mlt_properties b_props = mlt_frame_properties( b_frame );
 
        // Only if mix is specified, otherwise a producer may set the mix
-       if ( mlt_properties_get( properties, "mix" ) != NULL )
+       if ( mlt_properties_get( properties, "start" ) != NULL )
        {
-               // A negative means crossfade
-               if ( mlt_properties_get_double( properties, "mix" ) < 0 )
+               // Determine the time position of this frame in the transition duration
+               mlt_position in = mlt_transition_get_in( this );
+               mlt_position out = mlt_transition_get_out( this );
+               mlt_position time = mlt_frame_get_position( b_frame );
+               double mix = ( double )( time - in ) / ( double )( out - in + 1 );
+               
+               // If there is an end mix level adjust mix to the range
+               if ( mlt_properties_get( properties, "end" ) != NULL )
                {
-                       // Determine the time position of this frame in the transition duration
-                       mlt_position in = mlt_transition_get_in( this );
-                       mlt_position out = mlt_transition_get_out( this );
-                       mlt_position time = mlt_frame_get_position( b_frame );
-                       double mix = ( double )( time - in ) / ( double )( out - in + 1 );
-                       mlt_properties_set_double( b_props, "audio.mix", mix );
+                       double start = mlt_properties_get_double( properties, "start" );
+                       double end = mlt_properties_get_double( properties, "end" );
+                       mix = start + ( end - start ) * mix;
                }
-               else
-                       mlt_properties_set_double( b_props, "audio.mix", mlt_properties_get_double( properties, "mix" ) );
-       }
+               // A negative means total crossfade (uses position)
+               else if ( mlt_properties_get_double( properties, "start" ) >= 0 )
+               {
+                       // Otherwise, start/constructor is a constant mix level
+                   mix = mlt_properties_get_double( properties, "start" );
+               }
+       
+               // Finally, set the mix property on the frame
+               mlt_properties_set_double( b_props, "audio.mix", mix );
+
+               // Initialise transition previous mix value to prevent an inadvertant jump from 0
+               if ( mlt_properties_get( properties, "previous_mix" ) == NULL )
+                       mlt_properties_set_double( properties, "previous_mix", mlt_properties_get_double( b_props, "audio.mix" ) );
                        
+               // Tell b frame what the previous mix level was
+               mlt_properties_set_double( b_props, "audio.previous_mix", mlt_properties_get_double( properties, "previous_mix" ) );
+
+               // Save the current mix level for the next iteration
+               mlt_properties_set_double( properties, "previous_mix", mlt_properties_get_double( b_props, "audio.mix" ) );
+               
+               mlt_properties_set_double( b_props, "audio.reverse", mlt_properties_get_double( properties, "reverse" ) );
+       }
+
+       // Ensure that the tractor knows this isn't test audio...
+       if ( mlt_properties_get_int( mlt_frame_properties( a_frame ), "test_audio" ) )
+       {
+               mlt_properties_set_int( mlt_frame_properties( a_frame ), "test_audio", 0 );
+               mlt_properties_set_int( mlt_frame_properties( a_frame ), "silent_audio", 1 );
+       }
+
        // Backup the original get_audio (it's still needed)
        mlt_properties_set_data( mlt_frame_properties( a_frame ), "mix.get_audio", a_frame->get_audio, 0, NULL, NULL );
 
        // Override the get_audio method
        a_frame->get_audio = transition_get_audio;
        
-       mlt_frame_push_frame( a_frame, b_frame );
+       mlt_frame_push_audio( a_frame, b_frame );
        
        return a_frame;
 }
@@ -100,7 +135,8 @@ mlt_transition transition_mix_init( char *arg )
        {
                this->process = transition_process;
                if ( arg != NULL )
-                       mlt_properties_set_double( mlt_transition_properties( this ), "mix", atof( arg ) );
+                       mlt_properties_set_double( mlt_transition_properties( this ), "start", atof( arg ) );
+               mlt_properties_set_int( mlt_transition_properties( this ), "_accepts_blanks", 1 );
        }
        return this;
 }