#include "config.h"
#include "mlt_frame.h"
+#include "mlt_producer.h"
+#include "mlt_factory.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
-typedef struct
-{
- mlt_image_format vfmt;
- int width;
- int height;
- uint8_t *image;
- uint8_t *alpha;
- mlt_audio_format afmt;
- int16_t *audio;
-}
-frame_test;
-
-static frame_test test_card = { mlt_image_none, 0, 0, NULL, NULL, mlt_audio_none, NULL };
-
/** Constructor for a frame.
*/
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_timecode( properties, "timecode", 0.0 );
+ mlt_properties_set_position( properties, "_position", 0.0 );
mlt_properties_set_data( properties, "image", NULL, 0, NULL, NULL );
- mlt_properties_set_int( properties, "width", 720 );
- mlt_properties_set_int( properties, "height", 576 );
- mlt_properties_set_double( properties, "aspect_ratio", 4.0 / 3.0 );
+
+ 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", 72.0/79.0 );
+ }
+ 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", 128.0/117.0 );
+ }
+
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;
}
int mlt_frame_is_test_card( mlt_frame this )
{
- return this->stack_get_image_size == 0;
+ 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.
+*/
+
+int mlt_frame_is_test_audio( mlt_frame this )
+{
+ return this->get_audio == NULL || 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 )
{
- mlt_properties properties = mlt_frame_properties( this );
- return mlt_properties_get_double( properties, "aspect_ratio" );
+ 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 )
{
- mlt_properties properties = mlt_frame_properties( this );
- return mlt_properties_set_double( properties, "aspect_ratio", value );
+ return mlt_properties_set_double( mlt_frame_properties( this ), "aspect_ratio", value );
}
-/** Get the timecode of this frame.
+/** Get the position of this frame.
*/
-mlt_timecode mlt_frame_get_timecode( mlt_frame this )
+mlt_position mlt_frame_get_position( mlt_frame this )
{
- mlt_properties properties = mlt_frame_properties( this );
- return mlt_properties_get_timecode( properties, "timecode" );
+ return mlt_properties_get_position( mlt_frame_properties( this ), "_position" );
}
-/** Set the timecode of this frame.
+/** Set the position of this frame.
*/
-int mlt_frame_set_timecode( mlt_frame this, mlt_timecode value )
+int mlt_frame_set_position( mlt_frame this, mlt_position value )
{
- mlt_properties properties = mlt_frame_properties( this );
- return mlt_properties_set_timecode( properties, "timecode", 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 )
{
- 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.
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.
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.
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 )
{
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 );
if ( get_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", "nearest" );
+ 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 );
+ }
+ else
+ {
+ mlt_properties_set_data( properties, "test_card_producer", NULL, 0, NULL, NULL );
+ mlt_frame_get_image( this, buffer, format, width, height, writable );
+ }
+ }
else
{
- if ( test_card.vfmt != *format )
+ uint8_t *p;
+ 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", 1 );
+
+ switch( *format )
{
- uint8_t *p;
- uint8_t *q;
-
- test_card.vfmt = *format;
- test_card.width = *width == 0 ? 720 : *width;
- test_card.height = *height == 0 ? 576 : *height;
-
- switch( *format )
- {
- case mlt_image_none:
- break;
- case mlt_image_rgb24:
- test_card.image = realloc( test_card.image, test_card.width * test_card.height * 3 );
- memset( test_card.image, 255, test_card.width * test_card.height * 3 );
- break;
- case mlt_image_rgb24a:
- test_card.image = realloc( test_card.image, test_card.width * test_card.height * 4 );
- memset( test_card.image, 255, test_card.width * test_card.height * 4 );
- break;
- case mlt_image_yuv422:
- test_card.image = realloc( test_card.image, test_card.width * test_card.height * 2 );
- p = test_card.image;
- q = test_card.image + test_card.width * test_card.height * 2;
- while ( p != q )
- {
- *p ++ = 255;
- *p ++ = 128;
- }
- break;
- case mlt_image_yuv420p:
- test_card.image = realloc( test_card.image, test_card.width * test_card.height * 3 / 2 );
- memset( test_card.image, 255, test_card.width * test_card.height * 3 / 2 );
- break;
- }
+ 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;
}
- *width = test_card.width;
- *height = test_card.height;
- *buffer = test_card.image;
+ mlt_properties_set_data( properties, "image", *buffer, size, ( mlt_destructor )mlt_pool_release, NULL );
+ mlt_properties_set_int( properties, "test_image", 1 );
}
return 0;
{
if ( this->get_alpha_mask != NULL )
return this->get_alpha_mask( this );
- return test_card.alpha;
+ return 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 );
+
if ( this->get_audio != NULL )
{
return this->get_audio( this, buffer, format, frequency, channels, samples );
}
else
{
- if ( test_card.afmt != *format )
- {
- test_card.afmt = *format;
- test_card.audio = realloc( test_card.audio, 1920 * 2 * sizeof( int16_t ) );
- memset( test_card.audio, 0, 1920 * 2 * sizeof( int16_t ) );
- }
-
- *buffer = test_card.audio;
- *frequency = 48000;
- *channels = 2;
- *samples = 1920;
+ 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 );
}
return 0;
}
void mlt_frame_close( mlt_frame this )
{
- mlt_frame frame = mlt_frame_pop_frame( this );
-
- while ( frame != NULL )
+ if ( this != NULL )
{
- mlt_frame_close( frame);
- frame = mlt_frame_pop_frame( this );
+ mlt_deque_close( this->stack_image );
+ mlt_deque_close( this->stack_audio );
+ mlt_properties_close( &this->parent );
+ free( this );
}
-
- 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 )
{
return ret;
}
-int mlt_frame_composite_yuv( mlt_frame this, mlt_frame that, int x, int y, float weight )
-{
- int ret = 0;
- int width_src, height_src;
- int width_dest, height_dest;
- mlt_image_format format_src, format_dest;
- uint8_t *p_src, *p_dest;
- int i, j;
- int stride_src;
- int stride_dest;
- int x_src = 0, y_src = 0;
-
- // optimization point - no work to do
- if ( ( x < 0 && -x >= width_src ) || ( y < 0 && -y >= height_src ) )
- return ret;
-
- format_src = mlt_image_yuv422;
- format_dest = mlt_image_yuv422;
-
- mlt_frame_get_image( this, &p_dest, &format_dest, &width_dest, &height_dest, 1 /* writable */ );
- mlt_frame_get_image( that, &p_src, &format_src, &width_src, &height_src, 0 /* writable */ );
-
- stride_src = width_src * 2;
- stride_dest = width_dest * 2;
-
- // crop overlay off the left edge of frame
- if ( x < 0 )
- {
- x_src = -x;
- width_src -= x_src;
- x = 0;
- }
-
- // crop overlay beyond right edge of frame
- else if ( x + width_src > width_dest )
- width_src = width_dest - x;
-
- // crop overlay off the top edge of the frame
- if ( y < 0 )
- {
- y_src = -y;
- height_src -= y_src;
- }
- // crop overlay below bottom edge of frame
- else if ( y + height_src > height_dest )
- height_src = height_dest - y;
-
- // offset pointer into overlay buffer based on cropping
- p_src += x_src * 2 + y_src * stride_src;
-
- // offset pointer into frame buffer based upon positive, even coordinates only!
-// if ( interlaced && y % 2 )
-// ++y;
- p_dest += ( x < 0 ? 0 : x ) * 2 + ( y < 0 ? 0 : y ) * stride_dest;
-
- // Get the alpha channel of the overlay
- uint8_t *p_alpha = mlt_frame_get_alpha_mask( that );
-
- // offset pointer into alpha channel based upon cropping
- if ( p_alpha )
- p_alpha += x_src + y_src * stride_src / 2;
-
- // now do the compositing only to cropped extents
- for ( i = 0; i < height_src; i++ )
- {
- uint8_t *p = p_src;
- uint8_t *q = p_dest;
- uint8_t *o = p_dest;
- uint8_t *z = p_alpha;
-
- for ( j = 0; j < width_src; j ++ )
- {
- uint8_t y = *p ++;
- uint8_t uv = *p ++;
- uint8_t a = ( z == NULL ) ? 255 : *z ++;
- float value = ( weight * ( float ) a / 255.0 );
- *o ++ = (uint8_t)( y * value + *q++ * ( 1 - value ) );
- *o ++ = (uint8_t)( uv * value + *q++ * ( 1 - value ) );
- }
-
- p_src += stride_src;
- p_dest += stride_dest;
- if ( p_alpha )
- p_alpha += stride_src / 2;
- }
-
- return ret;
-}
-
-void *memfill( void *dst, void *src, int l, int elements )
-{
- int i = 0;
- for ( i = 0; i < elements; i ++ )
- dst = memcpy( dst, src, l ) + l;
- return dst;
-}
-
void mlt_resize_yuv422( uint8_t *output, int owidth, int oheight, uint8_t *input, int iwidth, int iheight )
{
// Calculate strides
iheight = iheight - ( iheight % 2 );
oheight = oheight - ( oheight % 2 );
+ // Optimisation point
+ if ( iwidth == owidth && iheight == oheight )
+ memcpy( output, input, iheight * istride );
+
// Coordinates (0,0 is middle of output)
int y;
uint8_t *in_middle = input + istride * ( iheight / 2 ) + ( iwidth / 2 ) * 2;
int in_line = - in_y_range * istride - in_x_range * 2;
- uint8_t black[ 2 ] = { 16, 128 };
+ 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 inactive_width = out_x_range - in_x_range;
+ uint8_t *p = NULL;
+ uint8_t *end = NULL;
// Loop for the entirety of our output height.
- for ( y = - out_y_range; y < out_y_range ; y ++ )
+ while ( iheight -- )
{
// Start at the beginning of the line
out_ptr = out_line;
- if ( abs( y ) < iheight / 2 )
+ // Fill the outer part with black
+ elements = inactive_width;
+ while ( elements -- )
{
- // Fill the outer part with black
- out_ptr = memfill( out_ptr, black, 2, out_x_range - in_x_range );
-
- // We're in the input range for this row.
- memcpy( out_ptr, in_middle + in_line, 2 * iwidth );
- out_ptr += 2 * iwidth;
-
- // Fill the outer part with black
- out_ptr = memfill( out_ptr, black, 2, out_x_range - in_x_range );
+ *out_ptr ++ = 16;
+ *out_ptr ++ = 128;
+ }
- // Move to next input line
- in_line += istride;
+ // 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 ++;
}
- else
+
+ // Fill the outer part with black
+ elements = inactive_width;
+ while ( elements -- )
{
- // Fill whole line with black
- out_ptr = memfill( out_ptr, black, 2, owidth );
+ *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
if ( iwidth != owidth || iheight != oheight )
{
// Create the output image
- uint8_t *output = malloc( owidth * oheight * 2 );
+ 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 * 2, free, NULL );
+ 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;
}
if ( iwidth != owidth || iheight != oheight )
{
// Create the output image
- uint8_t *output = malloc( owidth * oheight * 2 );
+ uint8_t *output = mlt_pool_alloc( owidth * ( oheight + 1 ) * 2 );
// Calculate strides
int istride = iwidth * 2;
iwidth = iwidth - ( iwidth % 4 );
- // Coordinates (0,0 is middle of output)
- int y, x;
-
// Derived coordinates
int dy, dx;
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
- float scale_width = ( float )iwidth / ( float )owidth;
- float scale_height = ( float )iheight / ( float )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;
-
// 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;
-
- // Check if x and y are in the valid input range.
- if ( abs( dx ) < in_x_range && abs( dy ) < in_y_range )
- {
- // We're in the input range for this row.
- in_ptr = in_line + ( dx >> 1 ) * 4 - 2 * ( x & 1 );
- *out_ptr ++ = *in_ptr ++;
- *out_ptr ++ = *in_ptr ++;
- }
- else
- {
- // We're not in the input range for this row.
- *out_ptr ++ = 16;
- *out_ptr ++ = 128;
- }
+ 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
}
// Now update the frame
- mlt_properties_set_data( properties, "image", output, owidth * oheight * 2, free, NULL );
+ 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 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( 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 );
+
+ 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 ( fps > 29 && fps <= 30 )
+ {
+ 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;
+}