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[melted] / src / framework / mlt_frame.c

diff --git a/src/framework/mlt_frame.c b/src/framework/mlt_frame.c
index f0092ed..e61db67 100644 (file)
--- a/src/framework/mlt_frame.c
+++ b/src/framework/mlt_frame.c
@@ -200,10 +200,16 @@ int mlt_frame_get_image( mlt_frame this, uint8_t **buffer, mlt_image_format *for
        mlt_properties properties = mlt_frame_properties( this );
        mlt_get_image get_image = mlt_frame_pop_get_image( this );
        mlt_producer producer = mlt_properties_get_data( properties, "test_card_producer", NULL );
+
+       *width = *width >> 1 << 1;
        
        if ( get_image != NULL )
        {
-               return get_image( this, buffer, format, width, height, writable );
+               int error = 0;
+               mlt_position position = mlt_frame_get_position( this );
+               error = get_image( this, buffer, format, width, height, writable );
+               mlt_frame_set_position( this, position );
+               return error;
        }
        else if ( mlt_properties_get_data( properties, "image", NULL ) != NULL )
        {
@@ -226,6 +232,7 @@ int mlt_frame_get_image( mlt_frame this, uint8_t **buffer, mlt_image_format *for
                        mlt_properties_set_data( properties, "image", *buffer, *width * *height * 2, NULL, NULL );
                        mlt_properties_set_int( properties, "width", *width );
                        mlt_properties_set_int( properties, "height", *height );
+                       mlt_properties_set_double( properties, "aspect_ratio", mlt_frame_get_aspect_ratio( test_frame ) );
                        mlt_properties_set( properties, "rescale.interp", "none" );
                        mlt_properties_set( properties, "scale", "off" );
                }
@@ -339,6 +346,61 @@ int mlt_frame_get_audio( mlt_frame this, int16_t **buffer, mlt_audio_format *for
        return 0;
 }
 
+unsigned char *mlt_frame_get_waveform( mlt_frame this, int w, int h )
+{
+       int16_t *pcm = NULL;
+       mlt_properties properties = mlt_frame_properties( this );
+       mlt_audio_format format = mlt_audio_pcm;
+       int frequency = 32000; // lower frequency available?
+       int channels = 2;
+       double fps = mlt_properties_get_double( properties, "fps" );
+       int samples = mlt_sample_calculator( fps, frequency, mlt_frame_get_position( this ) );
+       
+       // Get the pcm data
+       mlt_frame_get_audio( this, &pcm, &format, &frequency, &channels, &samples );
+       
+       // Make an 8-bit buffer large enough to hold rendering
+       int size = w * h;
+       unsigned char *bitmap = ( unsigned char* )mlt_pool_alloc( size );
+       if ( bitmap != NULL )
+               memset( bitmap, 0, size );
+       mlt_properties_set_data( properties, "waveform", bitmap, size, ( mlt_destructor )mlt_pool_release, NULL );
+       
+       // Render vertical lines
+       int16_t *ubound = pcm + samples * channels;
+       int skip = samples / w - 1;
+       int i, j, k;
+       
+       // Iterate sample stream and along x coordinate
+       for ( i = 0; i < w && pcm < ubound; i++ )
+       {
+               // pcm data has channels interleaved
+               for ( j = 0; j < channels; j++ )
+               {
+                       // Determine sample's magnitude from 2s complement;
+                       int pcm_magnitude = *pcm < 0 ? ~(*pcm) + 1 : *pcm;
+                       // The height of a line is the ratio of the magnitude multiplied by 
+                       // half the vertical resolution
+                       int height = ( int )( ( double )( pcm_magnitude ) / 32768 * h / 2 );
+                       // Determine the starting y coordinate - left channel above center,
+                       // right channel below - currently assumes 2 channels
+                       int displacement = ( h / 2 ) - ( 1 - j ) * height;
+                       // Position buffer pointer using y coordinate, stride, and x coordinate
+                       unsigned char *p = &bitmap[ i + displacement * w ];
+                       
+                       // Draw vertical line
+                       for ( k = 0; k < height; k++ )
+                               p[ w * k ] = 0xFF;
+                       
+                       pcm++;
+               }
+               pcm += skip * channels;
+       }
+
+       return bitmap;
+}
+
+
 void mlt_frame_close( mlt_frame this )
 {
        if ( this != NULL && mlt_properties_dec_ref( mlt_frame_properties( this ) ) <= 0 )