X-Git-Url: http://research.m1stereo.tv/gitweb?a=blobdiff_plain;f=src%2Fframework%2Fmlt_frame.c;h=7674633f725d5c030497b55c51af57c65fcc577c;hb=4dbf3ebb9b3642a02300bd2388c6b2211160cb5a;hp=fc67de8f2a395f18b70cf85e3ae802e4ee3f27a5;hpb=80761e7906f1694821044eefb3164b7f07c776e2;p=melted

diff --git a/src/framework/mlt_frame.c b/src/framework/mlt_frame.c
index fc67de8..7674633 100644
--- a/src/framework/mlt_frame.c
+++ b/src/framework/mlt_frame.c
@@ -339,13 +339,14 @@ 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, double fps, int w, int h )
+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
@@ -369,10 +370,11 @@ unsigned char *mlt_frame_get_waveform( mlt_frame this, double fps, int w, int h
 		// pcm data has channels interleaved
 		for ( j = 0; j < channels; j++ )
 		{
-			// The height of a line is the ratio of the sample multiplied by 
+			// 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 pcm_scaled = ( int )( ( double )( *pcm ) / 32768 * h / 2 );
-			int height = pcm_scaled < 0 ? -pcm_scaled : pcm_scaled;
+			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;