]> git.sesse.net Git - mlt/commitdiff
doc updates; property changes, and tweaks for volume filter normalisation
authorddennedy <ddennedy@d19143bc-622f-0410-bfdd-b5b2a6649095>
Wed, 28 Jan 2004 04:10:38 +0000 (04:10 +0000)
committerddennedy <ddennedy@d19143bc-622f-0410-bfdd-b5b2a6649095>
Wed, 28 Jan 2004 04:10:38 +0000 (04:10 +0000)
git-svn-id: https://mlt.svn.sourceforge.net/svnroot/mlt/trunk/mlt@99 d19143bc-622f-0410-bfdd-b5b2a6649095

docs/services.txt
src/modules/core/filter_volume.c

index 8cbed80ff102fd468353060416936c4be7991356..67cd91f99c9ccacb35361145eac919b2981f09d0 100644 (file)
@@ -313,6 +313,29 @@ Producers
 
                        Since it uses pipes, it is not compatible with bluefish.
 
+       westley
+
+               Description
+
+                       Construct a service network from an XML description.
+
+               Constructor Argument
+
+                       file - an XML text file containing westley XML (schema pending)
+
+               Read Only Properties
+
+                       string resource - file location
+
+               Dependencies
+
+                       libxml2
+
+               Known Bugs
+
+                       Non-referenced producers and playlists are not destroyed.
+                       A referenced producer or playlist must appear before the reference.
+
        vorbis
 
                Description
@@ -341,7 +364,6 @@ Producers
                        Fixed frame size (PAL audio chunks).
                        Doesn't cover ogg files with multiple, differing sections.
 
-
 Filters
 -------
 
@@ -492,7 +514,10 @@ Filters
                        
                Constructor Argument
 
-                       volume - a floating point value of the factor
+                       gain - a string containing one of:
+                                - a floating point value of the gain adjustment
+                                - a numeric value with the suffix "dB" to adjust in terms of decibels
+                                - "normalise" to normalise the volume to the target amplitude -12dBFS
                        
                Initialisation Properties
                
@@ -501,7 +526,20 @@ Filters
 
                Mutable Properties
 
-                       double volume - the factor applied to each sample
+                       string gain - same as constructor argument above
+
+                       string normalise - normalise the volume to the amplitude:
+                               - a numeric value with the suffix "dB" to set amplitude in decibels
+                               - a floating point value of the relative volume
+                               - an unspecified value uses the default -12dBFS
+
+                       string limiter - limit all samples above:
+                               - a numeric value with the suffix "dB"
+                               - a floating point value ( dB = 20 * log10(x) )
+                               - an unspecified value uses the default -6dBFS
+
+                       double max_gain - a floating point or decibel value of the maximum gain that
+                               can be applied during normalisation.
                        
                Dependencies
 
@@ -589,7 +627,7 @@ Transitions
                
                Constructor Argument
 
-                       string file - the luma map file name. If not supplied, a dissolve.
+                       string resource - the luma map file name. If not supplied, a dissolve.
 
                Initialisation Properties
                
@@ -598,7 +636,7 @@ Transitions
 
                Mutable Properties
 
-                       string filename - same as above
+                       string resource - same as above
                        double softness - only when using a luma map, how soft to make the
                                          edges between A and B. 0.0 = no softness. 1.0 =
                                          too soft.
@@ -737,3 +775,28 @@ Consumers
                        NTSC handling needs tightening up - sdl:NTSC is the only valid
                        constructor for NTSC playback at the moment.
 
+       westley
+
+               Description
+
+                       Serialise the service network to XML.
+                       
+               Constructor Argument
+
+                       resource - the name of a file in which to store the XML.
+                               stdout is used if not supplied.
+                       
+               Initialisation Properties
+
+                       string resource - same as above.
+                       
+               Dependencies
+               
+                       libxml2
+                       
+               Known Bugs
+
+                       Untested arbitrary nesting of multitracks and playlists.
+                       Property "id" is generated as service type followed by number if
+                       no property named "id" exists, but it fails to guarantee uniqueness.
+
index 719e3ed7abe4130967730f3b3320e541d655024f..72cc2143e2d8df8bccd3d79c6e3e365cad1418b5 100644 (file)
 #include <string.h>
 
 #define MAX_CHANNELS 6
-#define SMOOTH_BUFFER_SIZE 50
+#define SMOOTH_BUFFER_SIZE 75  /* smooth over 3 seconds on PAL */
+#define EPSILON 0.00001
 
-/* This utilities and limiter function comes from the normalize utility:
+/* The normalise functions come from the normalize utility:
    Copyright (C) 1999--2002 Chris Vaill */
 
 #define samp_width 16
@@ -68,15 +69,16 @@ int strncaseeq(const char *s1, const char *s2, size_t n)
 */
 static inline double limiter( double x, double lmtr_lvl )
 {
-       double xp;
+       double xp = x;
 
        if (x < -lmtr_lvl)
                xp = tanh((x + lmtr_lvl) / (1-lmtr_lvl)) * (1-lmtr_lvl) - lmtr_lvl;
-       else if (x <= lmtr_lvl)
-               xp = x;
-       else
+       else if (x > lmtr_lvl)
                xp = tanh((x - lmtr_lvl) / (1-lmtr_lvl)) * (1-lmtr_lvl) + lmtr_lvl;
 
+//     if ( x != xp )
+//             fprintf( stderr, "filter_volume: sample %f limited %f\n", x, xp );
+
        return xp;
 }
 
@@ -158,6 +160,8 @@ double signal_max_power( int16_t *buffer, int channels, int samples, int16_t *pe
        return sqrt( maxpow );
 }
 
+/* ------ End normalize functions --------------------------------------- */
+
 /** Get the audio.
 */
 
@@ -166,14 +170,17 @@ static int filter_get_audio( mlt_frame frame, int16_t **buffer, mlt_audio_format
        // Get the properties of the a frame
        mlt_properties properties = mlt_frame_properties( frame );
        double gain = mlt_properties_get_double( properties, "gain" );
-       int use_limiter =  mlt_properties_get_int( properties, "volume.use_limiter" );
-       double limiter_level =  mlt_properties_get_double( properties, "volume.limiter_level" );
+       double max_gain = mlt_properties_get_double( properties, "volume.max_gain" );
+       double limiter_level = 0.5; /* -6 dBFS */
        int normalise =  mlt_properties_get_int( properties, "volume.normalise" );
        double amplitude =  mlt_properties_get_double( properties, "volume.amplitude" );
        int i;
        double sample;
        int16_t peak;
 
+       if ( mlt_properties_get( properties, "volume.limiter" ) != NULL )
+               limiter_level = mlt_properties_get_double( properties, "volume.limiter" );
+       
        // Restore the original get_audio
        frame->get_audio = mlt_properties_get_data( properties, "volume.get_audio", NULL );
 
@@ -185,11 +192,6 @@ static int filter_get_audio( mlt_frame frame, int16_t **buffer, mlt_audio_format
        int samplemax = (1 << (bytes_per_samp * 8 - 1)) - 1;
        int samplemin = -samplemax - 1;
 
-#if 0
-       if ( gain > 1.0 && use_limiter != 0 )
-               fprintf(stderr, "filter_volume: limiting samples greater than %f\n", limiter_level );
-#endif
-
        if ( normalise )
        {
                double *smooth_buffer = mlt_properties_get_data( properties, "volume.smooth_buffer", NULL );
@@ -197,12 +199,23 @@ static int filter_get_audio( mlt_frame frame, int16_t **buffer, mlt_audio_format
 
                // Compute the signal power and put into smoothing buffer
                smooth_buffer[ *smooth_index ] = signal_max_power( *buffer, *channels, *samples, &peak );
-               *smooth_index = ( *smooth_index + 1 ) % SMOOTH_BUFFER_SIZE;
+//             fprintf( stderr, "filter_volume: raw power %f ", smooth_buffer[ *smooth_index ] );
+               if ( smooth_buffer[ *smooth_index ] > EPSILON )
+               {
+                       *smooth_index = ( *smooth_index + 1 ) % SMOOTH_BUFFER_SIZE;
 
-               // Smooth the data and compute the gain
-               gain *= amplitude / get_smoothed_data( smooth_buffer, SMOOTH_BUFFER_SIZE );
+                       // Smooth the data and compute the gain
+//                     fprintf( stderr, "smoothed %f\n", get_smoothed_data( smooth_buffer, SMOOTH_BUFFER_SIZE ) );
+                       gain *= amplitude / get_smoothed_data( smooth_buffer, SMOOTH_BUFFER_SIZE );
+               }
        }
        
+       if ( gain > 1.0 && normalise )
+               fprintf(stderr, "filter_volume: limiter level %f gain %f\n", limiter_level, gain );
+
+       if ( max_gain > 0 && gain > max_gain )
+               gain = max_gain;
+
        // Apply the gain
        for ( i = 0; i < ( *channels * *samples ); i++ )
        {
@@ -212,7 +225,7 @@ static int filter_get_audio( mlt_frame frame, int16_t **buffer, mlt_audio_format
                if ( gain > 1.0 )
                {
                        /* use limiter function instead of clipping */
-                       if ( use_limiter != 0 )
+                       if ( normalise )
                                (*buffer)[i] = ROUND( samplemax * limiter( sample / (double) samplemax, limiter_level ) );
                                
                        /* perform clipping */
@@ -234,17 +247,49 @@ static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
        mlt_properties properties = mlt_frame_properties( frame );
        mlt_properties filter_props = mlt_filter_properties( this );
 
-       // Propogate the volume/gain property
+       // Propogate the gain property
        if ( mlt_properties_get( properties, "gain" ) == NULL )
        {
-               double gain = 1.0; // none
-               if ( mlt_properties_get( filter_props, "volume" ) != NULL )
-                       gain = mlt_properties_get_double( filter_props, "volume" );
+               double gain = 1.0; // no adjustment
+               
                if ( mlt_properties_get( filter_props, "gain" ) != NULL )
-                       gain = mlt_properties_get_double( filter_props, "gain" );
+               {
+                       char *p = mlt_properties_get( filter_props, "gain" );
+                       
+                       if ( strncaseeq( p, "normalise", 9 ) )
+                               mlt_properties_set( filter_props, "normalise", "" );
+                       else
+                       {
+                               if ( strcmp( p, "" ) != 0 )
+                                       gain = fabs( strtod( p, &p) );
+
+                               while ( isspace( *p ) )
+                                       p++;
+
+                               /* check if "dB" is given after number */
+                               if ( strncaseeq( p, "db", 2 ) )
+                                       gain = DBFSTOAMP( gain );
+                       }
+               }
                mlt_properties_set_double( properties, "gain", gain );
        }
        
+       // Propogate the maximum gain property
+       if ( mlt_properties_get( filter_props, "max_gain" ) != NULL )
+       {
+               char *p = mlt_properties_get( filter_props, "max_gain" );
+               double gain = fabs( strtod( p, &p) ); // 0 = no max
+                       
+               while ( isspace( *p ) )
+                       p++;
+
+               /* check if "dB" is given after number */
+               if ( strncaseeq( p, "db", 2 ) )
+                       gain = DBFSTOAMP( gain );
+                       
+               mlt_properties_set_double( properties, "volume.max_gain", gain );
+       }
+
        // Parse and propogate the limiter property
        if ( mlt_properties_get( filter_props, "limiter" ) != NULL )
        {
@@ -253,10 +298,10 @@ static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
                if ( strcmp( p, "" ) != 0 )
                        level = strtod( p, &p);
                
-               /* check if "dB" is given after number */
                while ( isspace( *p ) )
                        p++;
                
+               /* check if "dB" is given after number */
                if ( strncaseeq( p, "db", 2 ) )
                {
                        if ( level > 0 )
@@ -268,8 +313,7 @@ static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
                        if ( level < 0 )
                                level = -level;
                }
-               mlt_properties_set_int( properties, "volume.use_limiter", 1 );
-               mlt_properties_set_double( properties, "volume.limiter_level", level );
+               mlt_properties_set_double( properties, "volume.limiter", level );
        }
 
        // Parse and propogate the normalise property
@@ -280,10 +324,10 @@ static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
                if ( strcmp( p, "" ) != 0 )
                        amplitude = strtod( p, &p);
 
-               /* check if "dB" is given after number */
                while ( isspace( *p ) )
                        p++;
 
+               /* check if "dB" is given after number */
                if ( strncaseeq( p, "db", 2 ) )
                {
                        if ( amplitude > 0 )
@@ -306,7 +350,7 @@ static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
                mlt_properties_get_data( filter_props, "smooth_buffer", NULL ), 0, NULL, NULL );
        mlt_properties_set_data( properties, "volume.smooth_index",
                mlt_properties_get_data( filter_props, "smooth_index", NULL ), 0, NULL, NULL );
-               
+
        // Backup the original get_audio (it's still needed)
        mlt_properties_set_data( properties, "volume.get_audio", frame->get_audio, 0, NULL, NULL );
 
@@ -324,9 +368,10 @@ mlt_filter filter_volume_init( char *arg )
        mlt_filter this = calloc( sizeof( struct mlt_filter_s ), 1 );
        if ( this != NULL && mlt_filter_init( this, NULL ) == 0 )
        {
+               mlt_properties properties = mlt_filter_properties( this );
                this->process = filter_process;
                if ( arg != NULL )
-                       mlt_properties_set_double( mlt_filter_properties( this ), "volume", atof( arg ) );
+                       mlt_properties_set( properties, "gain", arg );
 
                // Create a smoothing buffer for the calculated "max power" of frame of audio used in normalisation
                double *smooth_buffer = (double*) calloc( SMOOTH_BUFFER_SIZE, sizeof( double ) );