mlt_properties_set_int( properties, "test_image", 1 );
}
- mlt_properties_set_int( properties, "scaled_width", *width );
- mlt_properties_set_int( properties, "scaled_height", *height );
-
return error;
}
alpha = mlt_properties_get_data( &this->parent, "alpha", NULL );
if ( alpha == NULL )
{
- int size = mlt_properties_get_int( &this->parent, "scaled_width" ) * mlt_properties_get_int( &this->parent, "scaled_height" );
+ int size = mlt_properties_get_int( &this->parent, "width" ) * mlt_properties_get_int( &this->parent, "height" );
alpha = mlt_pool_alloc( size );
memset( alpha, 255, size );
mlt_properties_set_data( &this->parent, "alpha", alpha, size, mlt_pool_release, NULL );
int16_t *pcm = NULL;
mlt_properties properties = MLT_FRAME_PROPERTIES( this );
mlt_audio_format format = mlt_audio_s16;
- int frequency = 32000; // lower frequency available?
+ int frequency = 16000;
int channels = 2;
- double fps = mlt_profile_fps( NULL );
+ mlt_producer producer = mlt_frame_get_original_producer( this );
+ double fps = mlt_producer_get_fps( mlt_producer_cut_parent( producer ) );
int samples = mlt_sample_calculator( fps, frequency, mlt_frame_get_position( this ) );
+ // Increase audio resolution proportional to requested image size
+ while ( samples < w )
+ {
+ frequency += 16000;
+ samples = mlt_sample_calculator( fps, frequency, mlt_frame_get_position( this ) );
+ }
+
// Get the pcm data
mlt_frame_get_audio( this, (void**)&pcm, &format, &frequency, &channels, &samples );
// Render vertical lines
int16_t *ubound = pcm + samples * channels;
- int skip = samples / w - 1;
+ int skip = samples / w;
+ skip = !skip ? 1 : skip;
+ unsigned char gray = 0xFF / skip;
int i, j, k;
// Iterate sample stream and along x coordinate
- for ( i = 0; i < w && pcm < ubound; i++ )
+ for ( i = 0; pcm < ubound; i++ )
{
// pcm data has channels interleaved
- for ( j = 0; j < channels; j++ )
+ for ( j = 0; j < channels; j++, pcm++ )
{
// 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;
+ // the vertical resolution of a single channel
+ int height = h * pcm_magnitude / channels / 2 / 32768;
+ // Determine the starting y coordinate - left top, right bottom
+ int displacement = h * (j * 2 + 1) / channels / 2 - ( *pcm < 0 ? 0 : height );
// Position buffer pointer using y coordinate, stride, and x coordinate
- unsigned char *p = &bitmap[ i + displacement * w ];
+ unsigned char *p = bitmap + i / skip + displacement * w;
// Draw vertical line
- for ( k = 0; k < height; k++ )
- p[ w * k ] = 0xFF;
-
- pcm++;
+ for ( k = 0; k < height + 1; k++ )
+ if ( *pcm < 0 )
+ p[ w * k ] = ( k == 0 ) ? 0xFF : p[ w * k ] + gray;
+ else
+ p[ w * k ] = ( k == height ) ? 0xFF : p[ w * k ] + gray;
}
- pcm += skip * channels;
}
return bitmap;
return samples;
}
+
+void mlt_frame_write_ppm( mlt_frame frame )
+{
+ int width;
+ int height;
+ mlt_image_format format = mlt_image_rgb24;
+ uint8_t *image;
+
+ if ( mlt_frame_get_image( frame, &image, &format, &width, &height, 0 ) == 0 )
+ {
+ FILE *file;
+ char filename[16];
+
+ sprintf( filename, "frame-%05d.ppm", mlt_frame_get_position( frame ) );
+ file = fopen( filename, "wb" );
+ if ( !file )
+ return;
+ fprintf( file, "P6\n%d %d\n255\n", width, height);
+ fwrite( image, width * height * 3, 1, file );
+ fclose( file );
+ }
+}