X-Git-Url: http://research.m1stereo.tv/gitweb?a=blobdiff_plain;f=src%2Fframework%2Fmlt_frame.c;h=f072bdd1e4e461b47ff6b32472f0ca32f0413e80;hb=eabc3498604fc7983bbd805d40dad2e7df135f17;hp=48373607276a231a7d6901dc71d259ec279bd4c6;hpb=d5132b032c1fe4b26b785eddf4789702a44c3bca;p=melted

diff --git a/src/framework/mlt_frame.c b/src/framework/mlt_frame.c
index 4837360..f072bdd 100644
--- a/src/framework/mlt_frame.c
+++ b/src/framework/mlt_frame.c
@@ -25,6 +25,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <math.h>
 
 /** Constructor for a frame.
 */
@@ -53,7 +54,7 @@ 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", 72.0/79.0 );
+			mlt_properties_set_double( properties, "aspect_ratio", 59.0/54.0 );
 		}
 		else
 		{
@@ -61,7 +62,7 @@ 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", 128.0/117.0 );
+			mlt_properties_set_double( properties, "aspect_ratio", 10.0/11.0 );
 		}
 
 		mlt_properties_set_data( properties, "audio", NULL, 0, NULL, NULL );
@@ -70,6 +71,7 @@ mlt_frame mlt_frame_init( )
 		// Construct stacks for frames and methods
 		this->stack_image = mlt_deque_init( );
 		this->stack_audio = mlt_deque_init( );
+		this->stack_service = mlt_deque_init( );
 	}
 
 	return this;
@@ -88,15 +90,15 @@ mlt_properties mlt_frame_properties( mlt_frame this )
 
 int mlt_frame_is_test_card( mlt_frame this )
 {
-	return mlt_deque_count( this->stack_image ) == 0 || 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.
+/** Check if we have a way to derive something other than test audio.
 */
 
 int mlt_frame_is_test_audio( mlt_frame this )
 {
-	return this->get_audio == NULL || mlt_properties_get_int( mlt_frame_properties( this ), "test_audio" );
+	return mlt_deque_count( this->stack_audio ) == 0 || mlt_properties_get_int( MLT_FRAME_PROPERTIES( this ), "test_audio" );
 }
 
 /** Get the aspect ratio of the frame.
@@ -104,7 +106,7 @@ int mlt_frame_is_test_audio( mlt_frame this )
 
 double mlt_frame_get_aspect_ratio( mlt_frame this )
 {
-	return mlt_properties_get_double( mlt_frame_properties( this ), "aspect_ratio" );
+	return mlt_properties_get_double( MLT_FRAME_PROPERTIES( this ), "aspect_ratio" );
 }
 
 /** Set the aspect ratio of the frame.
@@ -112,7 +114,7 @@ double mlt_frame_get_aspect_ratio( mlt_frame this )
 
 int mlt_frame_set_aspect_ratio( mlt_frame this, double value )
 {
-	return mlt_properties_set_double( mlt_frame_properties( this ), "aspect_ratio", value );
+	return mlt_properties_set_double( MLT_FRAME_PROPERTIES( this ), "aspect_ratio", value );
 }
 
 /** Get the position of this frame.
@@ -120,7 +122,8 @@ int mlt_frame_set_aspect_ratio( mlt_frame this, double value )
 
 mlt_position mlt_frame_get_position( mlt_frame this )
 {
-	return mlt_properties_get_position( mlt_frame_properties( this ), "_position" );
+	int pos = mlt_properties_get_position( MLT_FRAME_PROPERTIES( this ), "_position" );
+	return pos < 0 ? 0 : pos;
 }
 
 /** Set the position of this frame.
@@ -128,7 +131,7 @@ mlt_position mlt_frame_get_position( mlt_frame this )
 
 int mlt_frame_set_position( mlt_frame this, mlt_position value )
 {
-	return mlt_properties_set_position( mlt_frame_properties( this ), "_position", value );
+	return mlt_properties_set_position( MLT_FRAME_PROPERTIES( this ), "_position", value );
 }
 
 /** Stack a get_image callback.
@@ -179,6 +182,22 @@ void *mlt_frame_pop_service( mlt_frame this )
 	return mlt_deque_pop_back( this->stack_image );
 }
 
+/** Push a service.
+*/
+
+int mlt_frame_push_service_int( mlt_frame this, int that )
+{
+	return mlt_deque_push_back_int( this->stack_image, that );
+}
+
+/** Pop a service.
+*/
+
+int mlt_frame_pop_service_int( mlt_frame this )
+{
+	return mlt_deque_pop_back_int( this->stack_image );
+}
+
 /** Push an audio item on the stack.
 */
 
@@ -195,21 +214,69 @@ void *mlt_frame_pop_audio( mlt_frame this )
 	return mlt_deque_pop_back( this->stack_audio );
 }
 
+/** Return the service stack
+*/
+
+mlt_deque mlt_frame_service_stack( mlt_frame this )
+{
+	return this->stack_service;
+}
+
+/** Replace image stack with the information provided.
+
+  	This might prove to be unreliable and restrictive - the idea is that a transition
+	which normally uses two images may decide to only use the b frame (ie: in the case
+	of a composite where the b frame completely obscures the a frame).
+
+	The image must be writable and the destructor for the image itself must be taken
+	care of on another frame and that frame cannot have a replace applied to it... 
+	Further it assumes that no alpha mask is in use.
+
+	For these reasons, it can only be used in a specific situation - when you have 
+	multiple tracks each with their own transition and these transitions are applied
+	in a strictly reversed order (ie: highest numbered [lowest track] is processed 
+	first).
+
+	More reliable approach - the cases should be detected during the process phase
+	and the upper tracks should simply not be invited to stack...
+*/
+
+void mlt_frame_replace_image( mlt_frame this, uint8_t *image, mlt_image_format format, int width, int height )
+{
+	// Remove all items from the stack
+	while( mlt_deque_pop_back( this->stack_image ) ) ;
+
+	// Update the information 
+	mlt_properties_set_data( MLT_FRAME_PROPERTIES( this ), "image", image, 0, NULL, NULL );
+	mlt_properties_set_int( MLT_FRAME_PROPERTIES( this ), "width", width );
+	mlt_properties_set_int( MLT_FRAME_PROPERTIES( this ), "height", height );
+	mlt_properties_set_int( MLT_FRAME_PROPERTIES( this ), "format", format );
+	this->get_alpha_mask = NULL;
+}
+
+/** Get the image associated to the frame.
+*/
+
 int mlt_frame_get_image( mlt_frame this, uint8_t **buffer, mlt_image_format *format, int *width, int *height, int writable )
 {
-	mlt_properties properties = mlt_frame_properties( this );
+	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 );
+	int error = 0;
 
-	*width = *width >> 1 << 1;
-	
 	if ( get_image != NULL )
 	{
-		return get_image( this, buffer, format, width, height, writable );
+		mlt_properties_set_int( properties, "image_count", mlt_properties_get_int( properties, "image_count" ) - 1 );
+		mlt_position position = mlt_frame_get_position( this );
+	   	error = get_image( this, buffer, format, width, height, writable );
+		mlt_properties_set_int( properties, "width", *width );
+		mlt_properties_set_int( properties, "height", *height );
+		mlt_properties_set_int( properties, "format", *format );
+		mlt_frame_set_position( this, position );
 	}
 	else if ( mlt_properties_get_data( properties, "image", NULL ) != NULL )
 	{
-		*format = mlt_image_yuv422;
+		*format = mlt_properties_get_int( properties, "format" );
 		*buffer = mlt_properties_get_data( properties, "image", NULL );
 		*width = mlt_properties_get_int( properties, "width" );
 		*height = mlt_properties_get_int( properties, "height" );
@@ -217,10 +284,10 @@ int mlt_frame_get_image( mlt_frame this, uint8_t **buffer, mlt_image_format *for
 	else if ( producer != NULL )
 	{
 		mlt_frame test_frame = NULL;
-		mlt_service_get_frame( mlt_producer_service( producer ), &test_frame, 0 );
+		mlt_service_get_frame( MLT_PRODUCER_SERVICE( producer ), &test_frame, 0 );
 		if ( test_frame != NULL )
 		{
-			mlt_properties test_properties = mlt_frame_properties( test_frame );
+			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( test_properties, "rescale.interp", mlt_properties_get( properties, "rescale.interp" ) );
 			mlt_frame_get_image( test_frame, buffer, format, width, height, writable );
@@ -228,8 +295,8 @@ 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( properties, "rescale.interp", "none" );
-			mlt_properties_set( properties, "scale", "off" );
+			mlt_properties_set_int( properties, "format", *format );
+			mlt_properties_set_double( properties, "aspect_ratio", mlt_frame_get_aspect_ratio( test_frame ) );
 		}
 		else
 		{
@@ -247,9 +314,10 @@ int mlt_frame_get_image( mlt_frame this, uint8_t **buffer, mlt_image_format *for
 		*height = *height == 0 ? 576 : *height;
 		size = *width * *height;
 
+		mlt_properties_set_int( properties, "format", *format );
 		mlt_properties_set_int( properties, "width", *width );
 		mlt_properties_set_int( properties, "height", *height );
-		mlt_properties_set_int( properties, "aspect_ratio", 1 );
+		mlt_properties_set_int( properties, "aspect_ratio", 0 );
 
 		switch( *format )
 		{
@@ -265,6 +333,7 @@ int mlt_frame_get_image( mlt_frame this, uint8_t **buffer, mlt_image_format *for
 					memset( *buffer, 255, size );
 				break;
 			case mlt_image_rgb24a:
+			case mlt_image_opengl:
 				size *= 4;
 				size += *width * 4;
 				*buffer = mlt_pool_alloc( size );
@@ -295,23 +364,43 @@ int mlt_frame_get_image( mlt_frame this, uint8_t **buffer, mlt_image_format *for
 		mlt_properties_set_int( properties, "test_image", 1 );
 	}
 
-	return 0;
+	mlt_properties_set_int( properties, "scaled_width", *width );
+	mlt_properties_set_int( properties, "scaled_height", *height );
+
+	return error;
 }
 
 uint8_t *mlt_frame_get_alpha_mask( mlt_frame this )
 {
-	if ( this->get_alpha_mask != NULL )
-		return this->get_alpha_mask( this );
-	return NULL;
+	uint8_t *alpha = NULL;
+	if ( this != NULL )
+	{
+		if ( this->get_alpha_mask != NULL )
+			alpha = this->get_alpha_mask( this );
+		if ( alpha == NULL )
+			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" );
+			alpha = mlt_pool_alloc( size );
+			memset( alpha, 255, size );
+			mlt_properties_set_data( &this->parent, "alpha", alpha, size, mlt_pool_release, NULL );
+		}
+	}
+	return alpha;
 }
 
 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 );
+	mlt_get_audio get_audio = mlt_frame_pop_audio( this );
+	mlt_properties properties = MLT_FRAME_PROPERTIES( this );
+	int hide = mlt_properties_get_int( properties, "test_audio" );
 
-	if ( this->get_audio != NULL )
+	if ( hide == 0 && get_audio != NULL )
 	{
-		this->get_audio( this, buffer, format, frequency, channels, samples );
+		mlt_position position = mlt_frame_get_position( this );
+		get_audio( this, buffer, format, frequency, channels, samples );
+		mlt_frame_set_position( this, position );
 	}
 	else if ( mlt_properties_get_data( properties, "audio", NULL ) )
 	{
@@ -338,13 +427,35 @@ int mlt_frame_get_audio( mlt_frame this, int16_t **buffer, mlt_audio_format *for
 	mlt_properties_set_int( properties, "audio_channels", *channels );
 	mlt_properties_set_int( properties, "audio_samples", *samples );
 
+	if ( mlt_properties_get( properties, "meta.volume" ) )
+	{
+		double value = mlt_properties_get_double( properties, "meta.volume" );
+
+		if ( value == 0.0 )
+		{
+			memset( *buffer, 0, *samples * *channels * 2 );
+		}
+		else if ( value != 1.0 )
+		{
+			int total = *samples * *channels;
+			int16_t *p = *buffer;
+			while ( total -- )
+			{
+				*p = *p * value;
+				p ++;
+			}
+		}
+
+		mlt_properties_set( properties, "meta.volume", NULL );
+	}
+
 	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_properties properties = MLT_FRAME_PROPERTIES( this );
 	mlt_audio_format format = mlt_audio_pcm;
 	int frequency = 32000; // lower frequency available?
 	int channels = 2;
@@ -395,13 +506,22 @@ unsigned char *mlt_frame_get_waveform( mlt_frame this, int w, int h )
 	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 )
 {
-	if ( this != NULL && mlt_properties_dec_ref( mlt_frame_properties( this ) ) <= 0 )
+	if ( this != NULL && mlt_properties_dec_ref( MLT_FRAME_PROPERTIES( this ) ) <= 0 )
 	{
 		mlt_deque_close( this->stack_image );
 		mlt_deque_close( this->stack_audio );
+		while( mlt_deque_peek_back( this->stack_service ) )
+			mlt_service_close( mlt_deque_pop_back( this->stack_service ) );
+		mlt_deque_close( this->stack_service );
 		mlt_properties_close( &this->parent );
 		free( this );
 	}
@@ -519,100 +639,88 @@ int mlt_convert_yuv420p_to_yuv422( uint8_t *yuv420p, int width, int height, int
 	return ret;
 }
 
-void mlt_resize_yuv422( uint8_t *output, int owidth, int oheight, uint8_t *input, int iwidth, int iheight )
+uint8_t *mlt_resize_alpha( uint8_t *input, int owidth, int oheight, int iwidth, int iheight, uint8_t alpha_value )
 {
-	// Calculate strides
-	int istride = iwidth * 2;
-	int ostride = owidth * 2;
+	uint8_t *output = NULL;
 
-	iwidth = iwidth - ( iwidth % 4 );
-	owidth = owidth - ( owidth % 4 );
-	iheight = iheight - ( iheight % 2 );
-	oheight = oheight - ( oheight % 2 );
+	if ( input != NULL && ( iwidth != owidth || iheight != oheight ) && ( owidth > 6 && oheight > 6 ) )
+	{
+		uint8_t *out_line;
+		int offset_x = ( owidth - iwidth ) / 2;
+		int offset_y = ( oheight - iheight ) / 2;
+		int iused = iwidth;
 
-	// Optimisation point
-	if ( iwidth == owidth && iheight == oheight )
-		memcpy( output, input, iheight * istride );
+		output = mlt_pool_alloc( owidth * oheight );
+		memset( output, alpha_value, owidth * oheight );
 
-   	// Coordinates (0,0 is middle of output)
-   	int y;
+		offset_x -= offset_x % 2;
 
-   	// 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;
+		out_line = output + offset_y * owidth;
+		out_line += offset_x;
 
-   	// Output pointers
-   	uint8_t *out_line = output;
-   	uint8_t *out_ptr = out_line;
+   		// Loop for the entirety of our output height.
+		while ( iheight -- )
+   		{
+   			// We're in the input range for this row.
+			memcpy( out_line, input, iused );
 
-   	// Calculate a middle and possibly invalid pointer in the input
-   	uint8_t *in_middle = input + istride * ( iheight / 2 ) + ( iwidth / 2 ) * 2;
-   	int in_line = - in_y_range * istride - in_x_range * 2;
+  			// Move to next input line
+   			input += iwidth;
 
-	int elements;
+       		// Move to next output line
+       		out_line += owidth;
+   		}
+	}
 
-	// Fill whole section with black
-	y = out_y_range - ( iheight / 2 );
-	int blank_elements = ostride * y / 2;
-	elements = blank_elements;
-	while ( elements -- )
+	return output;
+}
+
+void mlt_resize_yuv422( uint8_t *output, int owidth, int oheight, uint8_t *input, int iwidth, int iheight )
+{
+	// Calculate strides
+	int istride = iwidth * 2;
+	int ostride = owidth * 2;
+	int offset_x = ( owidth - iwidth );
+	int offset_y = ( oheight - iheight ) / 2;
+	uint8_t *in_line = input;
+	uint8_t *out_line;
+	int size = owidth * oheight;
+	uint8_t *p = output;
+
+	// Optimisation point
+	if ( output == NULL || input == NULL || ( owidth <= 6 || oheight <= 6 || iwidth <= 6 || oheight <= 6 ) )
 	{
-		*out_line ++ = 16;
-		*out_line ++ = 128;
+		return;
+	}
+	else if ( iwidth == owidth && iheight == oheight )
+	{
+		memcpy( output, input, iheight * istride );
+		return;
+	}
+
+	while( size -- )
+	{
+		*p ++ = 16;
+		*p ++ = 128;
 	}
 
-	int active_width = 2 * iwidth;
-	int inactive_width = out_x_range - in_x_range;
-	uint8_t *p = NULL;
-	uint8_t *end = NULL;
+	offset_x -= offset_x % 4;
+
+	out_line = output + offset_y * ostride;
+	out_line += offset_x;
 
    	// 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 ++ = 16;
-			*out_ptr ++ = 128;
-		}
-
    		// 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 ++;
-			*out_ptr ++ = *p ++;
-		}
-
-		// Fill the outer part with black
-		elements = inactive_width;
-		while ( elements -- )
-		{
-			*out_ptr ++ = 16;
-			*out_ptr ++ = 128;
-		}
+		memcpy( out_line, in_line, iwidth * 2 );
 
-  		// Move to next input line
-   		in_line += istride;
+		// Move to next input line
+		in_line += istride;
 
-       	// Move to next output line
-       	out_line += ostride;
+   		// Move to next output line
+   		out_line += ostride;
    	}
-
-	// Fill whole section with black
-	elements = blank_elements;
-	while ( elements -- )
-	{
-		*out_line ++ = 16;
-		*out_line ++ = 128;
-	}
 }
 
 /** A resizing function for yuv422 frames - this does not rescale, but simply
@@ -622,16 +730,20 @@ void mlt_resize_yuv422( uint8_t *output, int owidth, int oheight, uint8_t *input
 uint8_t *mlt_frame_resize_yuv422( mlt_frame this, int owidth, int oheight )
 {
 	// Get properties
-	mlt_properties properties = mlt_frame_properties( this );
+	mlt_properties properties = MLT_FRAME_PROPERTIES( this );
 
 	// 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" );
 
 	// If width and height are correct, don't do anything
 	if ( iwidth != owidth || iheight != oheight )
 	{
+		uint8_t alpha_value = mlt_properties_get_int( properties, "resize_alpha" );
+
 		// Create the output image
 		uint8_t *output = mlt_pool_alloc( owidth * ( oheight + 1 ) * 2 );
 
@@ -643,6 +755,14 @@ 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, alpha_value );
+		if ( alpha != NULL )
+		{
+			mlt_properties_set_data( properties, "alpha", alpha, owidth * oheight, ( mlt_destructor )mlt_pool_release, NULL );
+			this->get_alpha_mask = NULL;
+		}
+
 		// Return the output
 		return output;
 	}
@@ -657,7 +777,7 @@ uint8_t *mlt_frame_resize_yuv422( mlt_frame this, int owidth, int oheight )
 uint8_t *mlt_frame_rescale_yuv422( mlt_frame this, int owidth, int oheight )
 {
 	// Get properties
-	mlt_properties properties = mlt_frame_properties( this );
+	mlt_properties properties = MLT_FRAME_PROPERTIES( this );
 
 	// Get the input image, width and height
 	uint8_t *input = mlt_properties_get_data( properties, "image", NULL );
@@ -753,11 +873,19 @@ int mlt_frame_mix_audio( mlt_frame this, mlt_frame that, float weight_start, flo
 	int i, j;
 	double d = 0, s = 0;
 
-	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, &src, format, &frequency_src, &channels_src, &samples_src );
-	//fprintf( stderr, "mix: frame src  samples %d channels %d\n", samples_src, channels_src );
-	
+	mlt_frame_get_audio( this, &dest, format, &frequency_dest, &channels_dest, &samples_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 )
@@ -777,6 +905,15 @@ int mlt_frame_mix_audio( mlt_frame this, mlt_frame that, float weight_start, flo
 	float weight = weight_start;
 	float weight_step = ( weight_end - weight_start ) / *samples;
 
+	if ( src == dest )
+	{
+		*samples = samples_src;
+		*channels = channels_src;
+		*buffer = src;
+		*frequency = frequency_src;
+		return ret;
+	}
+
 	// Mixdown
 	for ( i = 0; i < *samples; i++ )
 	{
@@ -794,6 +931,72 @@ int mlt_frame_mix_audio( mlt_frame this, mlt_frame that, float weight_start, flo
 	return ret;
 }
 
+// Replacement for broken mlt_frame_audio_mix - this filter uses an inline low pass filter
+// to allow mixing without volume hacking
+int mlt_frame_combine_audio( mlt_frame this, mlt_frame that, int16_t **buffer, mlt_audio_format *format, int *frequency, int *channels, int *samples )
+{
+	int ret = 0;
+	int16_t *src, *dest;
+	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 vp[ 6 ];
+	double b_weight = 1.0;
+
+	if ( mlt_properties_get_int( MLT_FRAME_PROPERTIES( this ), "meta.mixdown" ) )
+		b_weight = 1.0 - mlt_properties_get_double( MLT_FRAME_PROPERTIES( this ), "meta.volume" );
+
+	mlt_frame_get_audio( that, &src, format, &frequency_src, &channels_src, &samples_src );
+	mlt_frame_get_audio( this, &dest, format, &frequency_dest, &channels_dest, &samples_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 ( src == dest )
+	{
+		*samples = samples_src;
+		*channels = channels_src;
+		*buffer = src;
+		*frequency = frequency_src;
+		return ret;
+	}
+
+	// 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 = dest;
+	*frequency = frequency_dest;
+
+	for ( j = 0; j < *channels; j++ )
+		vp[ j ] = ( double )dest[ j ];
+
+ 	double Fc = 0.5;
+ 	double B = exp(-2.0 * M_PI * Fc);
+	double A = 1.0 - B;
+	double v;
+	
+	for ( i = 0; i < *samples; i++ )
+	{
+		for ( j = 0; j < *channels; j++ )
+		{
+			v = ( double )( b_weight * dest[ i * channels_dest + j ] + src[ i * channels_src + j ] );
+			v = v < -32767 ? -32767 : v > 32768 ? 32768 : v;
+			vp[ j ] = dest[ i * channels_dest + j ] = ( int16_t )( v * A + vp[ j ] * B );
+		}
+	}
+
+	return ret;
+}
+
+/* Will this break when mlt_position is converted to double? -Zach */
 int mlt_sample_calculator( float fps, int frequency, int64_t position )
 {
 	int samples = 0;
@@ -839,3 +1042,32 @@ int mlt_sample_calculator( float fps, int frequency, int64_t position )
 
 	return samples;
 }
+
+int64_t mlt_sample_calculator_to_now( float fps, int frequency, int64_t frame )
+{
+	int64_t samples = 0;
+
+	// TODO: Correct rules for NTSC and drop the * 100 hack
+	if ( ( int )( fps * 100 ) == 2997 )
+	{
+		samples = ( ( double )( frame * frequency ) / 30 );
+		switch( frequency )
+		{
+			case 48000:
+				samples += 2 * ( frame / 5 );
+				break;
+			case 44100:
+				samples += frame + ( frame / 2 ) - ( frame / 30 ) + ( frame / 300 );
+				break;
+			case 32000:
+				samples += ( 2 * frame ) - ( frame / 4 ) - ( frame / 29 );
+				break;
+		}
+	}
+	else if ( fps != 0 )
+	{
+		samples = ( ( frame * frequency ) / ( int )fps );
+	}
+
+	return samples;
+}