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 );
// 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" );
+ mix_end = mlt_properties_get_double( b_props, "audio.mix" );
if ( mlt_properties_get_int( b_props, "audio.reverse" ) )
- mix = 1 - mix;
-
- mlt_frame_mix_audio( frame, b_frame, mix, buffer, format, frequency, channels, samples );
+ {
+ 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;
}
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 )
+ {
+ double start = mlt_properties_get_double( properties, "start" );
+ double end = mlt_properties_get_double( properties, "end" );
+ mix = start + ( end - start ) * mix;
+ }
+ // A negative means total crossfade (uses position)
+ else if ( mlt_properties_get_double( properties, "start" ) >= 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 );
- mlt_properties_set_double( b_props, "audio.mix", mix );
+ // Otherwise, start/constructor is a constant mix level
+ mix = mlt_properties_get_double( properties, "start" );
}
- else
- mlt_properties_set_double( b_props, "audio.mix", mlt_properties_get_double( properties, "mix" ) );
+
+ // 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" ) );
}
// 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;
}
{
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;
}