1026debf9e63e1928c930a36efacea83ea2df99f
[melted] / src / framework / mlt_frame.c
1 /*
2 * mlt_frame.c -- interface for all frame classes
3 * Copyright (C) 2003-2004 Ushodaya Enterprises Limited
4 * Author: Charles Yates <charles.yates@pandora.be>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software Foundation,
18 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19 */
20
21 #include "config.h"
22 #include "mlt_frame.h"
23 #include "mlt_producer.h"
24 #include "mlt_factory.h"
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <string.h>
28
29 /** Constructor for a frame.
30 */
31
32 mlt_frame mlt_frame_init( )
33 {
34 // Allocate a frame
35 mlt_frame this = calloc( sizeof( struct mlt_frame_s ), 1 );
36
37 if ( this != NULL )
38 {
39 // Get the normalisation
40 char *normalisation = mlt_environment( "MLT_NORMALISATION" );
41
42 // Initialise the properties
43 mlt_properties properties = &this->parent;
44 mlt_properties_init( properties, this );
45
46 // Set default properties on the frame
47 mlt_properties_set_position( properties, "_position", 0.0 );
48 mlt_properties_set_data( properties, "image", NULL, 0, NULL, NULL );
49
50 if ( normalisation == NULL || strcmp( normalisation, "NTSC" ) )
51 {
52 mlt_properties_set_int( properties, "width", 720 );
53 mlt_properties_set_int( properties, "height", 576 );
54 mlt_properties_set_int( properties, "normalised_width", 720 );
55 mlt_properties_set_int( properties, "normalised_height", 576 );
56 mlt_properties_set_double( properties, "aspect_ratio", 72.0/79.0 );
57 }
58 else
59 {
60 mlt_properties_set_int( properties, "width", 720 );
61 mlt_properties_set_int( properties, "height", 480 );
62 mlt_properties_set_int( properties, "normalised_width", 720 );
63 mlt_properties_set_int( properties, "normalised_height", 480 );
64 mlt_properties_set_double( properties, "aspect_ratio", 128.0/117.0 );
65 }
66
67 mlt_properties_set_data( properties, "audio", NULL, 0, NULL, NULL );
68 mlt_properties_set_data( properties, "alpha", NULL, 0, NULL, NULL );
69
70 // Construct stacks for frames and methods
71 this->stack_image = mlt_deque_init( );
72 this->stack_audio = mlt_deque_init( );
73 }
74
75 return this;
76 }
77
78 /** Fetch the frames properties.
79 */
80
81 mlt_properties mlt_frame_properties( mlt_frame this )
82 {
83 return &this->parent;
84 }
85
86 /** Check if we have a way to derive something other than a test card.
87 */
88
89 int mlt_frame_is_test_card( mlt_frame this )
90 {
91 return mlt_deque_count( this->stack_image ) == 0 || mlt_properties_get_int( mlt_frame_properties( this ), "test_image" );
92 }
93
94 /** Check if we have a way to derive something than test audio.
95 */
96
97 int mlt_frame_is_test_audio( mlt_frame this )
98 {
99 return this->get_audio == NULL || mlt_properties_get_int( mlt_frame_properties( this ), "test_audio" );
100 }
101
102 /** Get the aspect ratio of the frame.
103 */
104
105 double mlt_frame_get_aspect_ratio( mlt_frame this )
106 {
107 return mlt_properties_get_double( mlt_frame_properties( this ), "aspect_ratio" );
108 }
109
110 /** Set the aspect ratio of the frame.
111 */
112
113 int mlt_frame_set_aspect_ratio( mlt_frame this, double value )
114 {
115 return mlt_properties_set_double( mlt_frame_properties( this ), "aspect_ratio", value );
116 }
117
118 /** Get the position of this frame.
119 */
120
121 mlt_position mlt_frame_get_position( mlt_frame this )
122 {
123 return mlt_properties_get_position( mlt_frame_properties( this ), "_position" );
124 }
125
126 /** Set the position of this frame.
127 */
128
129 int mlt_frame_set_position( mlt_frame this, mlt_position value )
130 {
131 return mlt_properties_set_position( mlt_frame_properties( this ), "_position", value );
132 }
133
134 /** Stack a get_image callback.
135 */
136
137 int mlt_frame_push_get_image( mlt_frame this, mlt_get_image get_image )
138 {
139 return mlt_deque_push_back( this->stack_image, get_image );
140 }
141
142 /** Pop a get_image callback.
143 */
144
145 mlt_get_image mlt_frame_pop_get_image( mlt_frame this )
146 {
147 return mlt_deque_pop_back( this->stack_image );
148 }
149
150 /** Push a frame.
151 */
152
153 int mlt_frame_push_frame( mlt_frame this, mlt_frame that )
154 {
155 return mlt_deque_push_back( this->stack_image, that );
156 }
157
158 /** Pop a frame.
159 */
160
161 mlt_frame mlt_frame_pop_frame( mlt_frame this )
162 {
163 return mlt_deque_pop_back( this->stack_image );
164 }
165
166 /** Push a service.
167 */
168
169 int mlt_frame_push_service( mlt_frame this, void *that )
170 {
171 return mlt_deque_push_back( this->stack_image, that );
172 }
173
174 /** Pop a service.
175 */
176
177 void *mlt_frame_pop_service( mlt_frame this )
178 {
179 return mlt_deque_pop_back( this->stack_image );
180 }
181
182 /** Push an audio item on the stack.
183 */
184
185 int mlt_frame_push_audio( mlt_frame this, void *that )
186 {
187 return mlt_deque_push_back( this->stack_audio, that );
188 }
189
190 /** Pop an audio item from the stack
191 */
192
193 void *mlt_frame_pop_audio( mlt_frame this )
194 {
195 return mlt_deque_pop_back( this->stack_audio );
196 }
197
198 int mlt_frame_get_image( mlt_frame this, uint8_t **buffer, mlt_image_format *format, int *width, int *height, int writable )
199 {
200 mlt_properties properties = mlt_frame_properties( this );
201 mlt_get_image get_image = mlt_frame_pop_get_image( this );
202 mlt_producer producer = mlt_properties_get_data( properties, "test_card_producer", NULL );
203
204 if ( get_image != NULL )
205 {
206 return get_image( this, buffer, format, width, height, writable );
207 }
208 else if ( mlt_properties_get_data( properties, "image", NULL ) != NULL )
209 {
210 *format = mlt_image_yuv422;
211 *buffer = mlt_properties_get_data( properties, "image", NULL );
212 *width = mlt_properties_get_int( properties, "width" );
213 *height = mlt_properties_get_int( properties, "height" );
214 }
215 else if ( producer != NULL )
216 {
217 mlt_frame test_frame = NULL;
218 mlt_service_get_frame( mlt_producer_service( producer ), &test_frame, 0 );
219 if ( test_frame != NULL )
220 {
221 mlt_properties test_properties = mlt_frame_properties( test_frame );
222 mlt_properties_set_double( test_properties, "consumer_aspect_ratio", mlt_properties_get_double( properties, "consumer_aspect_ratio" ) );
223 mlt_properties_set( test_properties, "rescale.interp", mlt_properties_get( properties, "rescale.interp" ) );
224 mlt_frame_get_image( test_frame, buffer, format, width, height, writable );
225 mlt_properties_set_data( properties, "test_card_frame", test_frame, 0, ( mlt_destructor )mlt_frame_close, NULL );
226 mlt_properties_set_data( properties, "image", *buffer, *width * *height * 2, NULL, NULL );
227 mlt_properties_set_int( properties, "width", *width );
228 mlt_properties_set_int( properties, "height", *height );
229 mlt_properties_set( properties, "rescale.interp", "none" );
230 mlt_properties_set( properties, "scale", "off" );
231 }
232 else
233 {
234 mlt_properties_set_data( properties, "test_card_producer", NULL, 0, NULL, NULL );
235 mlt_frame_get_image( this, buffer, format, width, height, writable );
236 }
237 }
238 else
239 {
240 register uint8_t *p;
241 register uint8_t *q;
242 int size = 0;
243
244 *width = *width == 0 ? 720 : *width;
245 *height = *height == 0 ? 576 : *height;
246 size = *width * *height;
247
248 mlt_properties_set_int( properties, "width", *width );
249 mlt_properties_set_int( properties, "height", *height );
250 mlt_properties_set_int( properties, "aspect_ratio", 1 );
251
252 switch( *format )
253 {
254 case mlt_image_none:
255 size = 0;
256 *buffer = NULL;
257 break;
258 case mlt_image_rgb24:
259 size *= 3;
260 size += *width * 3;
261 *buffer = mlt_pool_alloc( size );
262 if ( *buffer )
263 memset( *buffer, 255, size );
264 break;
265 case mlt_image_rgb24a:
266 size *= 4;
267 size += *width * 4;
268 *buffer = mlt_pool_alloc( size );
269 if ( *buffer )
270 memset( *buffer, 255, size );
271 break;
272 case mlt_image_yuv422:
273 size *= 2;
274 size += *width * 2;
275 *buffer = mlt_pool_alloc( size );
276 p = *buffer;
277 q = p + size;
278 while ( p != NULL && p != q )
279 {
280 *p ++ = 235;
281 *p ++ = 128;
282 }
283 break;
284 case mlt_image_yuv420p:
285 size = size * 3 / 2;
286 *buffer = mlt_pool_alloc( size );
287 if ( *buffer )
288 memset( *buffer, 255, size );
289 break;
290 }
291
292 mlt_properties_set_data( properties, "image", *buffer, size, ( mlt_destructor )mlt_pool_release, NULL );
293 mlt_properties_set_int( properties, "test_image", 1 );
294 }
295
296 return 0;
297 }
298
299 uint8_t *mlt_frame_get_alpha_mask( mlt_frame this )
300 {
301 if ( this->get_alpha_mask != NULL )
302 return this->get_alpha_mask( this );
303 return NULL;
304 }
305
306 int mlt_frame_get_audio( mlt_frame this, int16_t **buffer, mlt_audio_format *format, int *frequency, int *channels, int *samples )
307 {
308 mlt_properties properties = mlt_frame_properties( this );
309
310 if ( this->get_audio != NULL )
311 {
312 this->get_audio( this, buffer, format, frequency, channels, samples );
313 }
314 else if ( mlt_properties_get_data( properties, "audio", NULL ) )
315 {
316 *buffer = mlt_properties_get_data( properties, "audio", NULL );
317 *frequency = mlt_properties_get_int( properties, "audio_frequency" );
318 *channels = mlt_properties_get_int( properties, "audio_channels" );
319 *samples = mlt_properties_get_int( properties, "audio_samples" );
320 }
321 else
322 {
323 int size = 0;
324 *samples = *samples <= 0 ? 1920 : *samples;
325 *channels = *channels <= 0 ? 2 : *channels;
326 *frequency = *frequency <= 0 ? 48000 : *frequency;
327 size = *samples * *channels * sizeof( int16_t );
328 *buffer = mlt_pool_alloc( size );
329 if ( *buffer != NULL )
330 memset( *buffer, 0, size );
331 mlt_properties_set_data( properties, "audio", *buffer, size, ( mlt_destructor )mlt_pool_release, NULL );
332 mlt_properties_set_int( properties, "test_audio", 1 );
333 }
334
335 mlt_properties_set_int( properties, "audio_frequency", *frequency );
336 mlt_properties_set_int( properties, "audio_channels", *channels );
337 mlt_properties_set_int( properties, "audio_samples", *samples );
338
339 return 0;
340 }
341
342 void mlt_frame_close( mlt_frame this )
343 {
344 if ( this != NULL )
345 {
346 mlt_deque_close( this->stack_image );
347 mlt_deque_close( this->stack_audio );
348 mlt_properties_close( &this->parent );
349 free( this );
350 }
351 }
352
353 /***** convenience functions *****/
354
355 int mlt_convert_rgb24a_to_yuv422( uint8_t *rgba, int width, int height, int stride, uint8_t *yuv, uint8_t *alpha )
356 {
357 int ret = 0;
358 register int y0, y1, u0, u1, v0, v1;
359 register int r, g, b;
360 register uint8_t *d = yuv;
361 register int i, j;
362
363 for ( i = 0; i < height; i++ )
364 {
365 register uint8_t *s = rgba + ( stride * i );
366 for ( j = 0; j < ( width / 2 ); j++ )
367 {
368 r = *s++;
369 g = *s++;
370 b = *s++;
371 *alpha++ = *s++;
372 RGB2YUV (r, g, b, y0, u0 , v0);
373 r = *s++;
374 g = *s++;
375 b = *s++;
376 *alpha++ = *s++;
377 RGB2YUV (r, g, b, y1, u1 , v1);
378 *d++ = y0;
379 *d++ = (u0+u1) >> 1;
380 *d++ = y1;
381 *d++ = (v0+v1) >> 1;
382 }
383 if ( width % 2 )
384 {
385 r = *s++;
386 g = *s++;
387 b = *s++;
388 *alpha++ = *s++;
389 RGB2YUV (r, g, b, y0, u0 , v0);
390 *d++ = y0;
391 *d++ = u0;
392 }
393 }
394 return ret;
395 }
396
397 int mlt_convert_rgb24_to_yuv422( uint8_t *rgb, int width, int height, int stride, uint8_t *yuv )
398 {
399 int ret = 0;
400 register int y0, y1, u0, u1, v0, v1;
401 register int r, g, b;
402 register uint8_t *d = yuv;
403 register int i, j;
404
405 for ( i = 0; i < height; i++ )
406 {
407 register uint8_t *s = rgb + ( stride * i );
408 for ( j = 0; j < ( width / 2 ); j++ )
409 {
410 r = *s++;
411 g = *s++;
412 b = *s++;
413 RGB2YUV (r, g, b, y0, u0 , v0);
414 r = *s++;
415 g = *s++;
416 b = *s++;
417 RGB2YUV (r, g, b, y1, u1 , v1);
418 *d++ = y0;
419 *d++ = (u0+u1) >> 1;
420 *d++ = y1;
421 *d++ = (v0+v1) >> 1;
422 }
423 if ( width % 2 )
424 {
425 r = *s++;
426 g = *s++;
427 b = *s++;
428 RGB2YUV (r, g, b, y0, u0 , v0);
429 *d++ = y0;
430 *d++ = u0;
431 }
432 }
433 return ret;
434 }
435
436 int mlt_convert_yuv420p_to_yuv422( uint8_t *yuv420p, int width, int height, int stride, uint8_t *yuv )
437 {
438 int ret = 0;
439 register int i, j;
440
441 int half = width >> 1;
442
443 uint8_t *Y = yuv420p;
444 uint8_t *U = Y + width * height;
445 uint8_t *V = U + width * height / 4;
446
447 register uint8_t *d = yuv;
448
449 for ( i = 0; i < height; i++ )
450 {
451 register uint8_t *u = U + ( i / 2 ) * ( half );
452 register uint8_t *v = V + ( i / 2 ) * ( half );
453
454 for ( j = 0; j < half; j++ )
455 {
456 *d ++ = *Y ++;
457 *d ++ = *u ++;
458 *d ++ = *Y ++;
459 *d ++ = *v ++;
460 }
461 }
462 return ret;
463 }
464
465 void mlt_resize_yuv422( uint8_t *output, int owidth, int oheight, uint8_t *input, int iwidth, int iheight )
466 {
467 // Calculate strides
468 int istride = iwidth * 2;
469 int ostride = owidth * 2;
470
471 iwidth = iwidth - ( iwidth % 4 );
472 owidth = owidth - ( owidth % 4 );
473 iheight = iheight - ( iheight % 2 );
474 oheight = oheight - ( oheight % 2 );
475
476 // Optimisation point
477 if ( iwidth == owidth && iheight == oheight )
478 memcpy( output, input, iheight * istride );
479
480 // Coordinates (0,0 is middle of output)
481 int y;
482
483 // Calculate ranges
484 int out_x_range = owidth / 2;
485 int out_y_range = oheight / 2;
486 int in_x_range = iwidth / 2 < out_x_range ? iwidth / 2 : out_x_range;
487 int in_y_range = iheight / 2 < out_y_range ? iheight / 2 : out_y_range;
488
489 // Output pointers
490 uint8_t *out_line = output;
491 uint8_t *out_ptr = out_line;
492
493 // Calculate a middle and possibly invalid pointer in the input
494 uint8_t *in_middle = input + istride * ( iheight / 2 ) + ( iwidth / 2 ) * 2;
495 int in_line = - in_y_range * istride - in_x_range * 2;
496
497 int elements;
498
499 // Fill whole section with black
500 y = out_y_range - ( iheight / 2 );
501 int blank_elements = ostride * y / 2;
502 elements = blank_elements;
503 while ( elements -- )
504 {
505 *out_line ++ = 16;
506 *out_line ++ = 128;
507 }
508
509 int active_width = 2 * iwidth;
510 int inactive_width = out_x_range - in_x_range;
511 uint8_t *p = NULL;
512 uint8_t *end = NULL;
513
514 // Loop for the entirety of our output height.
515 while ( iheight -- )
516 {
517 // Start at the beginning of the line
518 out_ptr = out_line;
519
520 // Fill the outer part with black
521 elements = inactive_width;
522 while ( elements -- )
523 {
524 *out_ptr ++ = 16;
525 *out_ptr ++ = 128;
526 }
527
528 // We're in the input range for this row.
529 p = in_middle + in_line;
530 end = out_ptr + active_width;
531 while ( out_ptr != end )
532 {
533 *out_ptr ++ = *p ++;
534 *out_ptr ++ = *p ++;
535 }
536
537 // Fill the outer part with black
538 elements = inactive_width;
539 while ( elements -- )
540 {
541 *out_ptr ++ = 16;
542 *out_ptr ++ = 128;
543 }
544
545 // Move to next input line
546 in_line += istride;
547
548 // Move to next output line
549 out_line += ostride;
550 }
551
552 // Fill whole section with black
553 elements = blank_elements;
554 while ( elements -- )
555 {
556 *out_line ++ = 16;
557 *out_line ++ = 128;
558 }
559 }
560
561 /** A resizing function for yuv422 frames - this does not rescale, but simply
562 resizes. It assumes yuv422 images available on the frame so use with care.
563 */
564
565 uint8_t *mlt_frame_resize_yuv422( mlt_frame this, int owidth, int oheight )
566 {
567 // Get properties
568 mlt_properties properties = mlt_frame_properties( this );
569
570 // Get the input image, width and height
571 uint8_t *input = mlt_properties_get_data( properties, "image", NULL );
572 int iwidth = mlt_properties_get_int( properties, "width" );
573 int iheight = mlt_properties_get_int( properties, "height" );
574
575 // If width and height are correct, don't do anything
576 if ( iwidth != owidth || iheight != oheight )
577 {
578 // Create the output image
579 uint8_t *output = mlt_pool_alloc( owidth * ( oheight + 1 ) * 2 );
580
581 // Call the generic resize
582 mlt_resize_yuv422( output, owidth, oheight, input, iwidth, iheight );
583
584 // Now update the frame
585 mlt_properties_set_data( properties, "image", output, owidth * ( oheight + 1 ) * 2, ( mlt_destructor )mlt_pool_release, NULL );
586 mlt_properties_set_int( properties, "width", owidth );
587 mlt_properties_set_int( properties, "height", oheight );
588
589 // Return the output
590 return output;
591 }
592 // No change, return input
593 return input;
594 }
595
596 /** A rescaling function for yuv422 frames - low quality, and provided for testing
597 only. It assumes yuv422 images available on the frame so use with care.
598 */
599
600 uint8_t *mlt_frame_rescale_yuv422( mlt_frame this, int owidth, int oheight )
601 {
602 // Get properties
603 mlt_properties properties = mlt_frame_properties( this );
604
605 // Get the input image, width and height
606 uint8_t *input = mlt_properties_get_data( properties, "image", NULL );
607 int iwidth = mlt_properties_get_int( properties, "width" );
608 int iheight = mlt_properties_get_int( properties, "height" );
609
610 // If width and height are correct, don't do anything
611 if ( iwidth != owidth || iheight != oheight )
612 {
613 // Create the output image
614 uint8_t *output = mlt_pool_alloc( owidth * ( oheight + 1 ) * 2 );
615
616 // Calculate strides
617 int istride = iwidth * 2;
618 int ostride = owidth * 2;
619
620 iwidth = iwidth - ( iwidth % 4 );
621
622 // Derived coordinates
623 int dy, dx;
624
625 // Calculate ranges
626 int out_x_range = owidth / 2;
627 int out_y_range = oheight / 2;
628 int in_x_range = iwidth / 2;
629 int in_y_range = iheight / 2;
630
631 // Output pointers
632 register uint8_t *out_line = output;
633 register uint8_t *out_ptr;
634
635 // Calculate a middle pointer
636 uint8_t *in_middle = input + istride * in_y_range + in_x_range * 2;
637 uint8_t *in_line;
638
639 // Generate the affine transform scaling values
640 register int scale_width = ( iwidth << 16 ) / owidth;
641 register int scale_height = ( iheight << 16 ) / oheight;
642 register int base = 0;
643
644 int outer = out_x_range * scale_width;
645 int bottom = out_y_range * scale_height;
646
647 // Loop for the entirety of our output height.
648 for ( dy = - bottom; dy < bottom; dy += scale_height )
649 {
650 // Start at the beginning of the line
651 out_ptr = out_line;
652
653 // Pointer to the middle of the input line
654 in_line = in_middle + ( dy >> 16 ) * istride;
655
656 // Loop for the entirety of our output row.
657 for ( dx = - outer; dx < outer; dx += scale_width )
658 {
659 base = dx >> 15;
660 base &= 0xfffffffe;
661 *out_ptr ++ = *( in_line + base );
662 base &= 0xfffffffc;
663 *out_ptr ++ = *( in_line + base + 1 );
664 dx += scale_width;
665 base = dx >> 15;
666 base &= 0xfffffffe;
667 *out_ptr ++ = *( in_line + base );
668 base &= 0xfffffffc;
669 *out_ptr ++ = *( in_line + base + 3 );
670 }
671
672 // Move to next output line
673 out_line += ostride;
674 }
675
676 // Now update the frame
677 mlt_properties_set_data( properties, "image", output, owidth * ( oheight + 1 ) * 2, ( mlt_destructor )mlt_pool_release, NULL );
678 mlt_properties_set_int( properties, "width", owidth );
679 mlt_properties_set_int( properties, "height", oheight );
680
681 // Return the output
682 return output;
683 }
684
685 // No change, return input
686 return input;
687 }
688
689 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 )
690 {
691 int ret = 0;
692 int16_t *src, *dest;
693 int frequency_src = *frequency, frequency_dest = *frequency;
694 int channels_src = *channels, channels_dest = *channels;
695 int samples_src = *samples, samples_dest = *samples;
696 int i, j;
697 double d = 0, s = 0;
698
699 mlt_frame_get_audio( this, &dest, format, &frequency_dest, &channels_dest, &samples_dest );
700 //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" ) );
701 mlt_frame_get_audio( that, &src, format, &frequency_src, &channels_src, &samples_src );
702 //fprintf( stderr, "mix: frame src samples %d channels %d\n", samples_src, channels_src );
703
704 if ( channels_src > 6 )
705 channels_src = 0;
706 if ( channels_dest > 6 )
707 channels_dest = 0;
708 if ( samples_src > 4000 )
709 samples_src = 0;
710 if ( samples_dest > 4000 )
711 samples_dest = 0;
712
713 // determine number of samples to process
714 *samples = samples_src < samples_dest ? samples_src : samples_dest;
715 *channels = channels_src < channels_dest ? channels_src : channels_dest;
716 *buffer = dest;
717 *frequency = frequency_dest;
718
719 // Compute a smooth ramp over start to end
720 float weight = weight_start;
721 float weight_step = ( weight_end - weight_start ) / *samples;
722
723 // Mixdown
724 for ( i = 0; i < *samples; i++ )
725 {
726 for ( j = 0; j < *channels; j++ )
727 {
728 if ( j < channels_dest )
729 d = (double) dest[ i * channels_dest + j ];
730 if ( j < channels_src )
731 s = (double) src[ i * channels_src + j ];
732 dest[ i * channels_dest + j ] = s * weight + d * ( 1.0 - weight );
733 }
734 weight += weight_step;
735 }
736
737 return ret;
738 }
739
740 int mlt_sample_calculator( float fps, int frequency, int64_t position )
741 {
742 int samples = 0;
743
744 if ( ( int )( fps * 100 ) == 2997 )
745 {
746 samples = frequency / 30;
747
748 switch ( frequency )
749 {
750 case 48000:
751 if ( position % 5 != 0 )
752 samples += 2;
753 break;
754 case 44100:
755 if ( position % 300 == 0 )
756 samples = 1471;
757 else if ( position % 30 == 0 )
758 samples = 1470;
759 else if ( position % 2 == 0 )
760 samples = 1472;
761 else
762 samples = 1471;
763 break;
764 case 32000:
765 if ( position % 30 == 0 )
766 samples = 1068;
767 else if ( position % 29 == 0 )
768 samples = 1067;
769 else if ( position % 4 == 2 )
770 samples = 1067;
771 else
772 samples = 1068;
773 break;
774 default:
775 samples = 0;
776 }
777 }
778 else if ( fps != 0 )
779 {
780 samples = frequency / fps;
781 }
782
783 return samples;
784 }