added brightness filter, added smooth ramping to audio processing, added start/end...

[mlt] / src / framework / mlt_frame.c

diff --git a/src/framework/mlt_frame.c b/src/framework/mlt_frame.c
index 2fef7c080de63e6ac2ef088aeddba86f6c77f62f..7e661fed9b9a6582682bda6f6c87f1bbe531d7aa 100644 (file)
--- a/src/framework/mlt_frame.c
+++ b/src/framework/mlt_frame.c
@@ -601,7 +601,7 @@ uint8_t *mlt_frame_rescale_yuv422( mlt_frame this, int owidth, int oheight )
        return input;
 }
 
-int mlt_frame_mix_audio( mlt_frame this, mlt_frame that, float weight, int16_t **buffer, mlt_audio_format *format, int *frequency, int *channels, int *samples )
+int mlt_frame_mix_audio( mlt_frame this, mlt_frame that, float weight_start, float weight_end, int16_t **buffer, mlt_audio_format *format, int *frequency, int *channels, int *samples )
 {
        int ret = 0;
        int16_t *p_src, *p_dest;
@@ -659,6 +659,10 @@ int mlt_frame_mix_audio( mlt_frame this, mlt_frame that, float weight, int16_t *
        *buffer = p_dest;
        *frequency = frequency_dest;
 
+       // Compute a smooth ramp over start to end
+       float weight = weight_start;
+       float weight_step = ( weight_end - weight_start ) / *samples;
+
        // Mixdown
        for ( i = 0; i < *samples; i++ )
        {
@@ -670,6 +674,7 @@ int mlt_frame_mix_audio( mlt_frame this, mlt_frame that, float weight, int16_t *
                                s = (double) src[ i * channels_src + j ];
                        dest[ i * channels_dest + j ] = s * weight + d * ( 1.0 - weight );
                }
+               weight += weight_step;
        }
 
        // We have to copy --sigh