]> git.sesse.net Git - mlt/blobdiff - src/framework/mlt_frame.c
Attempt at an aspect ratio clean up
[mlt] / src / framework / mlt_frame.c
index 409d3687a862555dc9a852299044c336dbeca705..6e23964e82e79d0b755b92f84595dac8fe8c7bef 100644 (file)
@@ -21,6 +21,7 @@
 #include "config.h"
 #include "mlt_frame.h"
 #include "mlt_producer.h"
+#include "mlt_factory.h"
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -36,7 +37,7 @@ mlt_frame mlt_frame_init( )
        if ( this != NULL )
        {
                // Get the normalisation
-               char *normalisation = getenv( "MLT_NORMALISATION" );
+               char *normalisation = mlt_environment( "MLT_NORMALISATION" );
 
                // Initialise the properties
                mlt_properties properties = &this->parent;
@@ -52,6 +53,7 @@ mlt_frame mlt_frame_init( )
                        mlt_properties_set_int( properties, "height", 576 );
                        mlt_properties_set_int( properties, "normalised_width", 720 );
                        mlt_properties_set_int( properties, "normalised_height", 576 );
+                       mlt_properties_set_double( properties, "aspect_ratio", 59.0/54.0 );
                }
                else
                {
@@ -59,14 +61,17 @@ mlt_frame mlt_frame_init( )
                        mlt_properties_set_int( properties, "height", 480 );
                        mlt_properties_set_int( properties, "normalised_width", 720 );
                        mlt_properties_set_int( properties, "normalised_height", 480 );
+                       mlt_properties_set_double( properties, "aspect_ratio", 10.0/11.0 );
                }
 
-               mlt_properties_set_double( properties, "aspect_ratio", 4.0 / 3.0 );
                mlt_properties_set_data( properties, "audio", NULL, 0, NULL, NULL );
                mlt_properties_set_data( properties, "alpha", NULL, 0, NULL, NULL );
 
-
+               // Construct stacks for frames and methods
+               this->stack_image = mlt_deque_init( );
+               this->stack_audio = mlt_deque_init( );
        }
+
        return this;
 }
 
@@ -75,7 +80,7 @@ mlt_frame mlt_frame_init( )
 
 mlt_properties mlt_frame_properties( mlt_frame this )
 {
-       return &this->parent;
+       return this != NULL ? &this->parent : NULL;
 }
 
 /** Check if we have a way to derive something other than a test card.
@@ -83,7 +88,7 @@ mlt_properties mlt_frame_properties( mlt_frame this )
 
 int mlt_frame_is_test_card( mlt_frame this )
 {
-       return mlt_properties_get_int( mlt_frame_properties( this ), "test_image" );
+       return mlt_deque_count( this->stack_image ) == 0 || mlt_properties_get_int( mlt_frame_properties( this ), "test_image" );
 }
 
 /** Check if we have a way to derive something than test audio.
@@ -131,10 +136,7 @@ int mlt_frame_set_position( mlt_frame this, mlt_position value )
 
 int mlt_frame_push_get_image( mlt_frame this, mlt_get_image get_image )
 {
-       int ret = this->stack_get_image_size >= 10;
-       if ( ret == 0 )
-               this->stack_get_image[ this->stack_get_image_size ++ ] = get_image;
-       return ret;
+       return mlt_deque_push_back( this->stack_image, get_image );
 }
 
 /** Pop a get_image callback.
@@ -142,10 +144,7 @@ int mlt_frame_push_get_image( mlt_frame this, mlt_get_image get_image )
 
 mlt_get_image mlt_frame_pop_get_image( mlt_frame this )
 {
-       mlt_get_image result = NULL;
-       if ( this->stack_get_image_size > 0 )
-               result = this->stack_get_image[ -- this->stack_get_image_size ];
-       return result;
+       return mlt_deque_pop_back( this->stack_image );
 }
 
 /** Push a frame.
@@ -153,10 +152,7 @@ mlt_get_image mlt_frame_pop_get_image( mlt_frame this )
 
 int mlt_frame_push_frame( mlt_frame this, mlt_frame that )
 {
-       int ret = this->stack_frame_size >= 10;
-       if ( ret == 0 )
-               this->stack_frame[ this->stack_frame_size ++ ] = that;
-       return ret;
+       return mlt_deque_push_back( this->stack_image, that );
 }
 
 /** Pop a frame.
@@ -164,10 +160,39 @@ int mlt_frame_push_frame( mlt_frame this, mlt_frame that )
 
 mlt_frame mlt_frame_pop_frame( mlt_frame this )
 {
-       mlt_frame result = NULL;
-       if ( this->stack_frame_size > 0 )
-               result = this->stack_frame[ -- this->stack_frame_size ];
-       return result;
+       return mlt_deque_pop_back( this->stack_image );
+}
+
+/** Push a service.
+*/
+
+int mlt_frame_push_service( mlt_frame this, void *that )
+{
+       return mlt_deque_push_back( this->stack_image, that );
+}
+
+/** Pop a service.
+*/
+
+void *mlt_frame_pop_service( mlt_frame this )
+{
+       return mlt_deque_pop_back( this->stack_image );
+}
+
+/** Push an audio item on the stack.
+*/
+
+int mlt_frame_push_audio( mlt_frame this, void *that )
+{
+       return mlt_deque_push_back( this->stack_audio, that );
+}
+
+/** Pop an audio item from the stack
+*/
+
+void *mlt_frame_pop_audio( mlt_frame this )
+{
+       return mlt_deque_pop_back( this->stack_audio );
 }
 
 int mlt_frame_get_image( mlt_frame this, uint8_t **buffer, mlt_image_format *format, int *width, int *height, int writable )
@@ -175,10 +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 )
        {
@@ -195,13 +226,13 @@ int mlt_frame_get_image( mlt_frame this, uint8_t **buffer, mlt_image_format *for
                {
                        mlt_properties test_properties = mlt_frame_properties( test_frame );
                        mlt_properties_set_double( test_properties, "consumer_aspect_ratio", mlt_properties_get_double( properties, "consumer_aspect_ratio" ) );
-                       mlt_properties_set_double( test_properties, "consumer_scale", mlt_properties_get_double( properties, "consumer_scale" ) );
-                       mlt_properties_set( test_properties, "rescale.interp", "nearest" );
+                       mlt_properties_set( test_properties, "rescale.interp", mlt_properties_get( properties, "rescale.interp" ) );
                        mlt_frame_get_image( test_frame, buffer, format, width, height, writable );
                        mlt_properties_set_data( properties, "test_card_frame", test_frame, 0, ( mlt_destructor )mlt_frame_close, NULL );
                        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 ) );
                }
                else
                {
@@ -211,8 +242,8 @@ int mlt_frame_get_image( mlt_frame this, uint8_t **buffer, mlt_image_format *for
        }
        else
        {
-               uint8_t *p;
-               uint8_t *q;
+               register uint8_t *p;
+               register uint8_t *q;
                int size = 0;
 
                *width = *width == 0 ? 720 : *width;
@@ -221,6 +252,7 @@ int mlt_frame_get_image( mlt_frame this, uint8_t **buffer, mlt_image_format *for
 
                mlt_properties_set_int( properties, "width", *width );
                mlt_properties_set_int( properties, "height", *height );
+               mlt_properties_set_int( properties, "aspect_ratio", 1 );
 
                switch( *format )
                {
@@ -250,7 +282,7 @@ int mlt_frame_get_image( mlt_frame this, uint8_t **buffer, mlt_image_format *for
                                q = p + size;
                                while ( p != NULL && p != q )
                                {
-                                       *p ++ = 255;
+                                       *p ++ = 235;
                                        *p ++ = 128;
                                }
                                break;
@@ -271,18 +303,28 @@ int mlt_frame_get_image( mlt_frame this, uint8_t **buffer, mlt_image_format *for
 
 uint8_t *mlt_frame_get_alpha_mask( mlt_frame this )
 {
-       if ( this->get_alpha_mask != NULL )
+       if ( this != NULL && this->get_alpha_mask != NULL )
                return this->get_alpha_mask( this );
-       return NULL;
+       return this == NULL ? NULL : mlt_properties_get_data( &this->parent, "alpha", NULL );
 }
 
 int mlt_frame_get_audio( mlt_frame this, int16_t **buffer, mlt_audio_format *format, int *frequency, int *channels, int *samples )
 {
        mlt_properties properties = mlt_frame_properties( this );
+       int hide = mlt_properties_get_int( properties, "test_audio" );
 
-       if ( this->get_audio != NULL )
+       if ( hide == 0 && this->get_audio != NULL )
+       {
+               mlt_position position = mlt_frame_get_position( this );
+               this->get_audio( this, buffer, format, frequency, channels, samples );
+               mlt_frame_set_position( this, position );
+       }
+       else if ( mlt_properties_get_data( properties, "audio", NULL ) )
        {
-               return this->get_audio( this, buffer, format, frequency, channels, samples );
+               *buffer = mlt_properties_get_data( properties, "audio", NULL );
+               *frequency = mlt_properties_get_int( properties, "audio_frequency" );
+               *channels = mlt_properties_get_int( properties, "audio_channels" );
+               *samples = mlt_properties_get_int( properties, "audio_samples" );
        }
        else
        {
@@ -297,26 +339,87 @@ int mlt_frame_get_audio( mlt_frame this, int16_t **buffer, mlt_audio_format *for
                mlt_properties_set_data( properties, "audio", *buffer, size, ( mlt_destructor )mlt_pool_release, NULL );
                mlt_properties_set_int( properties, "test_audio", 1 );
        }
+
+       mlt_properties_set_int( properties, "audio_frequency", *frequency );
+       mlt_properties_set_int( properties, "audio_channels", *channels );
+       mlt_properties_set_int( properties, "audio_samples", *samples );
+
        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;
+}
+
+mlt_producer mlt_frame_get_original_producer( mlt_frame this )
+{
+       if ( this != NULL )
+               return mlt_properties_get_data( mlt_frame_properties( this ), "_producer", NULL );
+       return NULL;
+}
+
 void mlt_frame_close( mlt_frame this )
 {
-       mlt_properties_close( &this->parent );
-       free( this );
+       if ( this != NULL && mlt_properties_dec_ref( mlt_frame_properties( this ) ) <= 0 )
+       {
+               mlt_deque_close( this->stack_image );
+               mlt_deque_close( this->stack_audio );
+               mlt_properties_close( &this->parent );
+               free( this );
+       }
 }
 
 /***** convenience functions *****/
-#define RGB2YUV(r, g, b, y, u, v)\
-  y = (306*r + 601*g + 117*b)  >> 10;\
-  u = ((-172*r - 340*g + 512*b) >> 10)  + 128;\
-  v = ((512*r - 429*g - 83*b) >> 10) + 128;\
-  y = y < 0 ? 0 : y;\
-  u = u < 0 ? 0 : u;\
-  v = v < 0 ? 0 : v;\
-  y = y > 255 ? 255 : y;\
-  u = u > 255 ? 255 : u;\
-  v = v > 255 ? 255 : v
 
 int mlt_convert_rgb24a_to_yuv422( uint8_t *rgba, int width, int height, int stride, uint8_t *yuv, uint8_t *alpha )
 {
@@ -428,6 +531,86 @@ int mlt_convert_yuv420p_to_yuv422( uint8_t *yuv420p, int width, int height, int
        return ret;
 }
 
+uint8_t *mlt_resize_alpha( uint8_t *input, int owidth, int oheight, int iwidth, int iheight )
+{
+       uint8_t *output = NULL;
+
+       if ( input != NULL && ( iwidth != owidth || iheight != oheight ) )
+       {
+               iwidth = iwidth - ( iwidth % 2 );
+               owidth = owidth - ( owidth % 2 );
+
+               output = mlt_pool_alloc( owidth * oheight );
+
+               // Coordinates (0,0 is middle of output)
+               int y;
+
+               // Calculate ranges
+               int out_x_range = owidth / 2;
+               int out_y_range = oheight / 2;
+               int in_x_range = iwidth / 2 < out_x_range ? iwidth / 2 : out_x_range;
+               int in_y_range = iheight / 2 < out_y_range ? iheight / 2 : out_y_range;
+
+               // Output pointers
+               uint8_t *out_line = output;
+               uint8_t *out_ptr = out_line;
+
+               // Calculate a middle and possibly invalid pointer in the input
+               uint8_t *in_middle = input + iwidth * ( iheight / 2 ) + ( iwidth / 2 );
+               int in_line = - in_y_range * iwidth - in_x_range;
+
+               int elements;
+
+               // Fill whole section with black
+               y = out_y_range - ( iheight / 2 );
+               int blank_elements = owidth * y;
+               elements = blank_elements;
+               while ( elements -- )
+                       *out_line ++ = 0;
+
+               int active_width = iwidth;
+               int inactive_width = out_x_range - in_x_range;
+               uint8_t *p = NULL;
+               uint8_t *end = NULL;
+
+               // Loop for the entirety of our output height.
+               while ( iheight -- )
+               {
+                       // Start at the beginning of the line
+                       out_ptr = out_line;
+
+                       // Fill the outer part with black
+                       elements = inactive_width;
+                       while ( elements -- )
+                               *out_ptr ++ = 0;
+
+                       // We're in the input range for this row.
+                       p = in_middle + in_line;
+                       end = out_ptr + active_width;
+                       while ( out_ptr != end )
+                               *out_ptr ++ = *p ++;
+
+                       // Fill the outer part with black
+                       elements = inactive_width;
+                       while ( elements -- )
+                               *out_ptr ++ = 0;
+       
+                       // Move to next input line
+                       in_line += iwidth;
+
+                       // Move to next output line
+                       out_line += owidth;
+               }
+
+               // Fill whole section with black
+               elements = blank_elements;
+               while ( elements -- )
+                       *out_line ++ = 0;
+       }
+
+       return output;
+}
+
 void mlt_resize_yuv422( uint8_t *output, int owidth, int oheight, uint8_t *input, int iwidth, int iheight )
 {
        // Calculate strides
@@ -436,8 +619,8 @@ void mlt_resize_yuv422( uint8_t *output, int owidth, int oheight, uint8_t *input
 
        iwidth = iwidth - ( iwidth % 4 );
        owidth = owidth - ( owidth % 4 );
-       iheight = iheight - ( iheight % 2 );
-       oheight = oheight - ( oheight % 2 );
+       //iheight = iheight - ( iheight % 2 );
+       //oheight = oheight - ( oheight % 2 );
 
        // Optimisation point
        if ( iwidth == owidth && iheight == oheight )
@@ -468,12 +651,14 @@ void mlt_resize_yuv422( uint8_t *output, int owidth, int oheight, uint8_t *input
        elements = blank_elements;
        while ( elements -- )
        {
-               *out_line ++ = 0;
+               *out_line ++ = 16;
                *out_line ++ = 128;
        }
 
        int active_width = 2 * iwidth;
        int inactive_width = out_x_range - in_x_range;
+       uint8_t *p = NULL;
+       uint8_t *end = NULL;
 
        // Loop for the entirety of our output height.
        while ( iheight -- )
@@ -485,19 +670,24 @@ void mlt_resize_yuv422( uint8_t *output, int owidth, int oheight, uint8_t *input
                elements = inactive_width;
                while ( elements -- )
                {
-                       *out_ptr ++ = 0;
+                       *out_ptr ++ = 16;
                        *out_ptr ++ = 128;
                }
 
                // We're in the input range for this row.
-               memcpy( out_ptr, in_middle + in_line, active_width );
-               out_ptr += active_width;
+               p = in_middle + in_line;
+               end = out_ptr + active_width;
+               while ( out_ptr != end )
+               {
+                       *out_ptr ++ = *p ++;
+                       *out_ptr ++ = *p ++;
+               }
 
                // Fill the outer part with black
                elements = inactive_width;
                while ( elements -- )
                {
-                       *out_ptr ++ = 0;
+                       *out_ptr ++ = 16;
                        *out_ptr ++ = 128;
                }
 
@@ -512,7 +702,7 @@ void mlt_resize_yuv422( uint8_t *output, int owidth, int oheight, uint8_t *input
        elements = blank_elements;
        while ( elements -- )
        {
-               *out_line ++ = 0;
+               *out_line ++ = 16;
                *out_line ++ = 128;
        }
 }
@@ -528,6 +718,8 @@ uint8_t *mlt_frame_resize_yuv422( mlt_frame this, int owidth, int oheight )
 
        // Get the input image, width and height
        uint8_t *input = mlt_properties_get_data( properties, "image", NULL );
+       uint8_t *alpha = mlt_frame_get_alpha_mask( this );
+
        int iwidth = mlt_properties_get_int( properties, "width" );
        int iheight = mlt_properties_get_int( properties, "height" );
 
@@ -545,6 +737,14 @@ uint8_t *mlt_frame_resize_yuv422( mlt_frame this, int owidth, int oheight )
                mlt_properties_set_int( properties, "width", owidth );
                mlt_properties_set_int( properties, "height", oheight );
 
+               // We should resize the alpha too
+               alpha = mlt_resize_alpha( alpha, owidth, oheight, iwidth, iheight );
+               if ( alpha != NULL )
+               {
+                       mlt_properties_set_data( properties, "alpha", alpha, owidth * ( oheight + 1 ), ( mlt_destructor )mlt_pool_release, NULL );
+                       this->get_alpha_mask = NULL;
+               }
+
                // Return the output
                return output;
        }
@@ -578,9 +778,6 @@ uint8_t *mlt_frame_rescale_yuv422( mlt_frame this, int owidth, int oheight )
 
                iwidth = iwidth - ( iwidth % 4 );
 
-       // Coordinates (0,0 is middle of output)
-       int y, x;
-
                // Derived coordinates
                int dy, dx;
 
@@ -591,41 +788,44 @@ uint8_t *mlt_frame_rescale_yuv422( mlt_frame this, int owidth, int oheight )
        int in_y_range = iheight / 2;
 
        // Output pointers
-       uint8_t *out_line = output;
-       uint8_t *out_ptr;
+       register uint8_t *out_line = output;
+       register uint8_t *out_ptr;
 
        // Calculate a middle pointer
        uint8_t *in_middle = input + istride * in_y_range + in_x_range * 2;
        uint8_t *in_line;
-               uint8_t *in_ptr;
 
                // Generate the affine transform scaling values
-               int scale_width = ( iwidth << 16 ) / owidth;
-               int scale_height = ( iheight << 16 ) / oheight;
+               register int scale_width = ( iwidth << 16 ) / owidth;
+               register int scale_height = ( iheight << 16 ) / oheight;
+               register int base = 0;
+
+               int outer = out_x_range * scale_width;
+               int bottom = out_y_range * scale_height;
 
        // Loop for the entirety of our output height.
-       for ( y = - out_y_range; y < out_y_range ; y ++ )
+       for ( dy = - bottom; dy < bottom; dy += scale_height )
        {
-                       // Calculate the derived y value
-                       dy = ( scale_height * y ) >> 16;
-
                // Start at the beginning of the line
                out_ptr = out_line;
        
                // Pointer to the middle of the input line
-               in_line = in_middle + dy * istride;
-       
+               in_line = in_middle + ( dy >> 16 ) * istride;
+
                // Loop for the entirety of our output row.
-               for ( x = - out_x_range; x < out_x_range; x += 1 )
+               for ( dx = - outer; dx < outer; dx += scale_width )
                {
-                               // Calculated the derived x
-                               dx = ( scale_width * x ) >> 16;
-
-                       // We're in the input range for this row.
-                               in_ptr = in_line + ( dx << 1 );
-                       *out_ptr ++ = *in_ptr ++;
-                               in_ptr = in_line + ( ( dx >> 1 ) << 2 ) + ( ( x & 1 ) << 1 ) + 1;
-                       *out_ptr ++ = *in_ptr;
+                               base = dx >> 15;
+                               base &= 0xfffffffe;
+                               *out_ptr ++ = *( in_line + base );
+                               base &= 0xfffffffc;
+                               *out_ptr ++ = *( in_line + base + 1 );
+                               dx += scale_width;
+                               base = dx >> 15;
+                               base &= 0xfffffffe;
+                               *out_ptr ++ = *( in_line + base );
+                               base &= 0xfffffffc;
+                               *out_ptr ++ = *( in_line + base + 3 );
                }
 
                // Move to next output line
@@ -648,22 +848,28 @@ uint8_t *mlt_frame_rescale_yuv422( mlt_frame this, int owidth, int oheight )
 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;
        int16_t *src, *dest;
-       //static int16_t *extra_src = NULL, *extra_dest = NULL;
-       static int extra_src_samples = 0, extra_dest_samples = 0;
        int frequency_src = *frequency, frequency_dest = *frequency;
        int channels_src = *channels, channels_dest = *channels;
        int samples_src = *samples, samples_dest = *samples;
        int i, j;
        double d = 0, s = 0;
 
-       mlt_frame_get_audio( this, &p_dest, format, &frequency_dest, &channels_dest, &samples_dest );
+       mlt_frame_get_audio( this, &dest, format, &frequency_dest, &channels_dest, &samples_dest );
        //fprintf( stderr, "mix: frame dest samples %d channels %d position %lld\n", samples_dest, channels_dest, mlt_properties_get_position( mlt_frame_properties( this ), "_position" ) );
-       mlt_frame_get_audio( that, &p_src, format, &frequency_src, &channels_src, &samples_src );
+       mlt_frame_get_audio( that, &src, format, &frequency_src, &channels_src, &samples_src );
        //fprintf( stderr, "mix: frame src  samples %d channels %d\n", samples_src, channels_src );
-       src = p_src;
-       dest = p_dest;
+
+       int silent = mlt_properties_get_int( mlt_frame_properties( this ), "silent_audio" );
+       mlt_properties_set_int( mlt_frame_properties( this ), "silent_audio", 0 );
+       if ( silent )
+               memset( dest, 0, samples_dest * channels_dest * sizeof( int16_t ) );
+
+       silent = mlt_properties_get_int( mlt_frame_properties( that ), "silent_audio" );
+       mlt_properties_set_int( mlt_frame_properties( that ), "silent_audio", 0 );
+       if ( silent )
+               memset( src, 0, samples_src * channels_src * sizeof( int16_t ) );
+
        if ( channels_src > 6 )
                channels_src = 0;
        if ( channels_dest > 6 )
@@ -673,34 +879,10 @@ int mlt_frame_mix_audio( mlt_frame this, mlt_frame that, float weight_start, flo
        if ( samples_dest > 4000 )
                samples_dest = 0;
 
-#if 0
-       // Append new samples to leftovers
-       if ( extra_dest_samples > 0 )
-       {
-               fprintf( stderr, "prepending %d samples to dest\n", extra_dest_samples );
-               dest = realloc( extra_dest, ( samples_dest + extra_dest_samples ) * 2 * channels_dest );
-               memcpy( &extra_dest[ extra_dest_samples * channels_dest ], p_dest, samples_dest * 2 * channels_dest );
-       }
-       else
-               dest = p_dest;
-       if ( extra_src_samples > 0 )
-       {
-               fprintf( stderr, "prepending %d samples to src\n", extra_src_samples );
-               src = realloc( extra_src, ( samples_src + extra_src_samples ) * 2 * channels_src );
-               memcpy( &extra_src[ extra_src_samples * channels_src ], p_src, samples_src * 2 * channels_src );
-       }
-       else
-               src = p_src;
-#endif
-
-       // determine number of samples to process       
-       if ( samples_src + extra_src_samples < samples_dest + extra_dest_samples )
-               *samples = samples_src + extra_src_samples;
-       else if ( samples_dest + extra_dest_samples < samples_src + extra_src_samples )
-               *samples = samples_dest + extra_dest_samples;
-       
+       // determine number of samples to process
+       *samples = samples_src < samples_dest ? samples_src : samples_dest;
        *channels = channels_src < channels_dest ? channels_src : channels_dest;
-       *buffer = p_dest;
+       *buffer = dest;
        *frequency = frequency_dest;
 
        // Compute a smooth ramp over start to end
@@ -721,40 +903,6 @@ int mlt_frame_mix_audio( mlt_frame this, mlt_frame that, float weight_start, flo
                weight += weight_step;
        }
 
-       // We have to copy --sigh
-       if ( dest != p_dest )
-               memcpy( p_dest, dest, *samples * 2 * *channels );
-
-#if 0
-       // Store the leftovers
-       if ( samples_src + extra_src_samples < samples_dest + extra_dest_samples )
-       {
-               extra_dest_samples = ( samples_dest + extra_dest_samples ) - ( samples_src + extra_src_samples );
-               size_t size = extra_dest_samples * 2 * channels_dest;
-               fprintf( stderr, "storing %d samples from dest\n", extra_dest_samples );
-               if ( extra_dest )
-                       free( extra_dest );
-               extra_dest = malloc( size );
-               if ( extra_dest )
-                       memcpy( extra_dest, &p_dest[ ( samples_dest - extra_dest_samples - 1 ) * channels_dest ], size );
-               else
-                       extra_dest_samples = 0;
-       }
-       else if ( samples_dest + extra_dest_samples < samples_src + extra_src_samples )
-       {
-               extra_src_samples = ( samples_src + extra_src_samples ) - ( samples_dest + extra_dest_samples );
-               size_t size = extra_src_samples * 2 * channels_src;
-               fprintf( stderr, "storing %d samples from src\n", extra_dest_samples );
-               if ( extra_src )
-                       free( extra_src );
-               extra_src = malloc( size );
-               if ( extra_src )
-                       memcpy( extra_src, &p_src[ ( samples_src - extra_src_samples - 1 ) * channels_src ], size );
-               else
-                       extra_src_samples = 0;
-       }
-#endif
-       
        return ret;
 }
 
@@ -762,7 +910,7 @@ int mlt_sample_calculator( float fps, int frequency, int64_t position )
 {
        int samples = 0;
 
-       if ( fps > 29 && fps <= 30 )
+       if ( ( int )( fps * 100 ) == 2997 )
        {
                samples = frequency / 30;
 
@@ -803,4 +951,3 @@ int mlt_sample_calculator( float fps, int frequency, int64_t position )
 
        return samples;
 }
-