/*
 * mlt_frame.c -- interface for all frame classes
 * Copyright (C) 2003-2004 Ushodaya Enterprises Limited
 * Author: Charles Yates <charles.yates@pandora.be>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#include "config.h"
#include "mlt_frame.h"
#include "mlt_producer.h"
#include "mlt_factory.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

/** Constructor for a frame.
*/

mlt_frame mlt_frame_init( )
{
	// Allocate a frame
	mlt_frame this = calloc( sizeof( struct mlt_frame_s ), 1 );

	if ( this != NULL )
	{
		// Get the normalisation
		char *normalisation = mlt_environment( "MLT_NORMALISATION" );

		// Initialise the properties
		mlt_properties properties = &this->parent;
		mlt_properties_init( properties, this );

		// Set default properties on the frame
		mlt_properties_set_position( properties, "_position", 0.0 );
		mlt_properties_set_data( properties, "image", NULL, 0, NULL, NULL );

		if ( normalisation == NULL || strcmp( normalisation, "NTSC" ) )
		{
			mlt_properties_set_int( properties, "width", 720 );
			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
		{
			mlt_properties_set_int( properties, "width", 720 );
			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_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( );
		this->stack_service = mlt_deque_init( );
	}

	return this;
}

/** Fetch the frames properties.
*/

mlt_properties mlt_frame_properties( mlt_frame this )
{
	return this != NULL ? &this->parent : NULL;
}

/** Check if we have a way to derive something other than a test card.
*/

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" );
}

/** Check if we have a way to derive something other than test audio.
*/

int mlt_frame_is_test_audio( mlt_frame this )
{
	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.
*/

double mlt_frame_get_aspect_ratio( mlt_frame this )
{
	return mlt_properties_get_double( MLT_FRAME_PROPERTIES( this ), "aspect_ratio" );
}

/** Set the aspect ratio of the frame.
*/

int mlt_frame_set_aspect_ratio( mlt_frame this, double value )
{
	return mlt_properties_set_double( MLT_FRAME_PROPERTIES( this ), "aspect_ratio", value );
}

/** Get the position of this frame.
*/

mlt_position mlt_frame_get_position( mlt_frame this )
{
	int pos = mlt_properties_get_position( MLT_FRAME_PROPERTIES( this ), "_position" );
	return pos < 0 ? 0 : pos;
}

/** Set the position of this frame.
*/

int mlt_frame_set_position( mlt_frame this, mlt_position value )
{
	return mlt_properties_set_position( MLT_FRAME_PROPERTIES( this ), "_position", value );
}

/** Stack a get_image callback.
*/

int mlt_frame_push_get_image( mlt_frame this, mlt_get_image get_image )
{
	return mlt_deque_push_back( this->stack_image, get_image );
}

/** Pop a get_image callback.
*/

mlt_get_image mlt_frame_pop_get_image( mlt_frame this )
{
	return mlt_deque_pop_back( this->stack_image );
}

/** Push a frame.
*/

int mlt_frame_push_frame( mlt_frame this, mlt_frame that )
{
	return mlt_deque_push_back( this->stack_image, that );
}

/** Pop a frame.
*/

mlt_frame mlt_frame_pop_frame( mlt_frame this )
{
	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 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.
*/

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 );
}

/** 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_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 )
	{
		mlt_position position = mlt_frame_get_position( this );
	   	error = get_image( this, buffer, format, width, height, writable );
		mlt_frame_set_position( this, position );
	}
	else if ( mlt_properties_get_data( properties, "image", NULL ) != NULL )
	{
		*format = mlt_image_yuv422;
		*buffer = mlt_properties_get_data( properties, "image", NULL );
		*width = mlt_properties_get_int( properties, "width" );
		*height = mlt_properties_get_int( properties, "height" );
	}
	else if ( producer != NULL )
	{
		mlt_frame test_frame = NULL;
		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_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 );
			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
		{
			mlt_properties_set_data( properties, "test_card_producer", NULL, 0, NULL, NULL );
			mlt_frame_get_image( this, buffer, format, width, height, writable );
		}
	}
	else
	{
		register uint8_t *p;
		register uint8_t *q;
		int size = 0;

		*width = *width == 0 ? 720 : *width;
		*height = *height == 0 ? 576 : *height;
		size = *width * *height;

		mlt_properties_set_int( properties, "width", *width );
		mlt_properties_set_int( properties, "height", *height );
		mlt_properties_set_int( properties, "aspect_ratio", 0 );

		switch( *format )
		{
			case mlt_image_none:
				size = 0;
				*buffer = NULL;
				break;
			case mlt_image_rgb24:
				size *= 3;
				size += *width * 3;
				*buffer = mlt_pool_alloc( size );
				if ( *buffer )
					memset( *buffer, 255, size );
				break;
			case mlt_image_rgb24a:
				size *= 4;
				size += *width * 4;
				*buffer = mlt_pool_alloc( size );
				if ( *buffer )
					memset( *buffer, 255, size );
				break;
			case mlt_image_yuv422:
				size *= 2;
				size += *width * 2;
				*buffer = mlt_pool_alloc( size );
				p = *buffer;
				q = p + size;
				while ( p != NULL && p != q )
				{
					*p ++ = 235;
					*p ++ = 128;
				}
				break;
			case mlt_image_yuv420p:
				size = size * 3 / 2;
				*buffer = mlt_pool_alloc( size );
				if ( *buffer )
					memset( *buffer, 255, size );
				break;
		}

		mlt_properties_set_data( properties, "image", *buffer, size, ( mlt_destructor )mlt_pool_release, NULL );
		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;
}

uint8_t *mlt_frame_get_alpha_mask( mlt_frame this )
{
	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_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 ( hide == 0 && get_audio != NULL )
	{
		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 ) )
	{
		*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
	{
		int size = 0;
		*samples = *samples <= 0 ? 1920 : *samples;
		*channels = *channels <= 0 ? 2 : *channels;
		*frequency = *frequency <= 0 ? 48000 : *frequency;
		size = *samples * *channels * sizeof( int16_t );
		*buffer = mlt_pool_alloc( size );
		if ( *buffer != NULL )
			memset( *buffer, 0, size );
		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 );

	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 );
			mlt_properties_set_double( properties, "meta.volume", 1.0 );
		}
		else if ( value != 1.0 )
		{
			int total = *samples * *channels;
			int16_t *p = *buffer;
			while ( total -- )
			{
				*p = *p * value;
				p ++;
			}
			mlt_properties_set_double( properties, "meta.volume", 1.0 );
		}
	}

	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 )
{
	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 );
	}
}

/***** convenience functions *****/

int mlt_convert_rgb24a_to_yuv422( uint8_t *rgba, int width, int height, int stride, uint8_t *yuv, uint8_t *alpha )
{
	int ret = 0;
	register int y0, y1, u0, u1, v0, v1;
	register int r, g, b;
	register uint8_t *d = yuv;
	register int i, j;

	for ( i = 0; i < height; i++ )
	{
		register uint8_t *s = rgba + ( stride * i );
		for ( j = 0; j < ( width / 2 ); j++ )
		{
			r = *s++;
			g = *s++;
			b = *s++;
			*alpha++ = *s++;
			RGB2YUV (r, g, b, y0, u0 , v0);
			r = *s++;
			g = *s++;
			b = *s++;
			*alpha++ = *s++;
			RGB2YUV (r, g, b, y1, u1 , v1);
			*d++ = y0;
			*d++ = (u0+u1) >> 1;
			*d++ = y1;
			*d++ = (v0+v1) >> 1;
		}
		if ( width % 2 )
		{
			r = *s++;
			g = *s++;
			b = *s++;
			*alpha++ = *s++;
			RGB2YUV (r, g, b, y0, u0 , v0);
			*d++ = y0;
			*d++ = u0;
		}
	}
	return ret;
}

int mlt_convert_rgb24_to_yuv422( uint8_t *rgb, int width, int height, int stride, uint8_t *yuv )
{
	int ret = 0;
	register int y0, y1, u0, u1, v0, v1;
	register int r, g, b;
	register uint8_t *d = yuv;
	register int i, j;

	for ( i = 0; i < height; i++ )
	{
		register uint8_t *s = rgb + ( stride * i );
		for ( j = 0; j < ( width / 2 ); j++ )
		{
			r = *s++;
			g = *s++;
			b = *s++;
			RGB2YUV (r, g, b, y0, u0 , v0);
			r = *s++;
			g = *s++;
			b = *s++;
			RGB2YUV (r, g, b, y1, u1 , v1);
			*d++ = y0;
			*d++ = (u0+u1) >> 1;
			*d++ = y1;
			*d++ = (v0+v1) >> 1;
		}
		if ( width % 2 )
		{
			r = *s++;
			g = *s++;
			b = *s++;
			RGB2YUV (r, g, b, y0, u0 , v0);
			*d++ = y0;
			*d++ = u0;
		}
	}
	return ret;
}

int mlt_convert_yuv420p_to_yuv422( uint8_t *yuv420p, int width, int height, int stride, uint8_t *yuv )
{
	int ret = 0;
	register int i, j;

	int half = width >> 1;

	uint8_t *Y = yuv420p;
	uint8_t *U = Y + width * height;
	uint8_t *V = U + width * height / 4;

	register uint8_t *d = yuv;

	for ( i = 0; i < height; i++ )
	{
		register uint8_t *u = U + ( i / 2 ) * ( half );
		register uint8_t *v = V + ( i / 2 ) * ( half );

		for ( j = 0; j < half; j++ )
		{
			*d ++ = *Y ++;
			*d ++ = *u ++;
			*d ++ = *Y ++;
			*d ++ = *v ++;
		}
	}
	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 ) && ( owidth > 6 && oheight > 6 ) )
	{
		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
	int istride = iwidth * 2;
	int ostride = owidth * 2;

	iwidth = iwidth - ( iwidth % 2 );
	owidth = owidth - ( owidth % 2 );
	//iheight = iheight - ( iheight % 2 );
	//oheight = oheight - ( oheight % 2 );
	
	// Optimisation point
	if ( output == NULL || input == NULL || ( owidth <= 6 || oheight <= 6 || iwidth <= 6 || oheight <= 6 ) )
	{
		return;
	}
	else if ( iwidth == owidth && iheight == oheight )
	{
		memcpy( output, input, iheight * istride );
		return;
	}

   	// 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 + istride * ( iheight / 2 ) + iwidth;
   	int in_line = - in_y_range * istride - in_x_range * 2;

	int elements;

	// Fill whole section with black
	y = out_y_range - ( iheight / 2 );
	int blank_elements = ostride * y / 2;
	elements = blank_elements;
	while ( elements -- )
	{
		*out_line ++ = 16;
		*out_line ++ = 128;
	}

	int active_width = 2 * iwidth;
	int left_inactive_width = out_x_range - in_x_range;
	int right_inactive_width = left_inactive_width;
	uint8_t *p = NULL;
	uint8_t *end = NULL;

	if ( in_line % 4 )
	{
		active_width -= 2;
		in_middle += 2;
		right_inactive_width += 2;
	}

   	// 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 = left_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 = right_inactive_width;
		while ( elements -- )
		{
			*out_ptr ++ = 16;
			*out_ptr ++ = 128;
		}

  		// Move to next input line
   		in_line += istride;

       	// 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
	resizes. It assumes yuv422 images available on the frame so use with care.
*/

uint8_t *mlt_frame_resize_yuv422( mlt_frame this, int owidth, int oheight )
{
	// Get properties
	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 )
	{
		// Create the output image
		uint8_t *output = mlt_pool_alloc( owidth * ( oheight + 1 ) * 2 );

		// Call the generic resize
		mlt_resize_yuv422( output, owidth, oheight, input, iwidth, iheight );

		// Now update the frame
		mlt_properties_set_data( properties, "image", output, owidth * ( oheight + 1 ) * 2, ( mlt_destructor )mlt_pool_release, NULL );
		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;
	}
	// No change, return input
	return input;
}

/** A rescaling function for yuv422 frames - low quality, and provided for testing
 	only. It assumes yuv422 images available on the frame so use with care.
*/

uint8_t *mlt_frame_rescale_yuv422( mlt_frame this, int owidth, int oheight )
{
	// Get properties
	mlt_properties properties = MLT_FRAME_PROPERTIES( this );

	// Get the input image, width and height
	uint8_t *input = mlt_properties_get_data( properties, "image", NULL );
	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 )
	{
		// Create the output image
		uint8_t *output = mlt_pool_alloc( owidth * ( oheight + 1 ) * 2 );

		// Calculate strides
		int istride = iwidth * 2;
		int ostride = owidth * 2;

		iwidth = iwidth - ( iwidth % 4 );

		// Derived coordinates
		int dy, dx;

    	// Calculate ranges
    	int out_x_range = owidth / 2;
    	int out_y_range = oheight / 2;
    	int in_x_range = iwidth / 2;
    	int in_y_range = iheight / 2;

    	// Output pointers
    	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;

		// Generate the affine transform scaling values
		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 ( dy = - bottom; dy < bottom; dy += scale_height )
    	{
        	// Start at the beginning of the line
        	out_ptr = out_line;
	
        	// Pointer to the middle of the input line
        	in_line = in_middle + ( dy >> 16 ) * istride;

        	// Loop for the entirety of our output row.
        	for ( dx = - outer; dx < outer; dx += scale_width )
        	{
				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
        	out_line += ostride;
    	}

		// Now update the frame
		mlt_properties_set_data( properties, "image", output, owidth * ( oheight + 1 ) * 2, ( mlt_destructor )mlt_pool_release, NULL );
		mlt_properties_set_int( properties, "width", owidth );
		mlt_properties_set_int( properties, "height", oheight );

		// Return the output
		return output;
	}

	// No change, return input
	return input;
}

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 *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 d = 0, s = 0;

	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 ( channels_src > 6 )
		channels_src = 0;
	if ( channels_dest > 6 )
		channels_dest = 0;
	if ( samples_src > 4000 )
		samples_src = 0;
	if ( samples_dest > 4000 )
		samples_dest = 0;

	// 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;

	// Compute a smooth ramp over start to end
	float weight = weight_start;
	float weight_step = ( weight_end - weight_start ) / *samples;

	// Mixdown
	for ( i = 0; i < *samples; i++ )
	{
		for ( j = 0; j < *channels; j++ )
		{
			if ( j < channels_dest )
				d = (double) dest[ i * channels_dest + j ];
			if ( j < channels_src )
				s = (double) src[ i * channels_src + j ];
			dest[ i * channels_dest + j ] = s * weight + d * ( 1.0 - weight );
		}
		weight += weight_step;
	}

	return ret;
}

int mlt_sample_calculator( float fps, int frequency, int64_t position )
{
	int samples = 0;

	if ( ( int )( fps * 100 ) == 2997 )
	{
		samples = frequency / 30;

		switch ( frequency )
		{
			case 48000:
				if ( position % 5 != 0 )
					samples += 2;
				break;
			case 44100:
				if ( position % 300 == 0 )
					samples = 1471;
				else if ( position % 30 == 0 )
					samples = 1470;
				else if ( position % 2 == 0 )
					samples = 1472;
				else
					samples = 1471;
				break;
			case 32000:
				if ( position % 30 == 0 )
					samples = 1068;
				else if ( position % 29 == 0 )
					samples = 1067;
				else if ( position % 4 == 2 )
					samples = 1067;
				else
					samples = 1068;
				break;
			default:
				samples = 0;
		}
	}
	else if ( fps != 0 )
	{
		samples = frequency / fps;
	}

	return samples;
}