research.m1stereo.tv/gitweb/ - melted/blob - 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 library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library 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 GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 #include "mlt_frame.h"
  22 #include "mlt_producer.h"
  23 #include "mlt_factory.h"
  24 #include "mlt_profile.h"
  25
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29 #include <math.h>
  30
  31 /** Constructor for a frame.
  32 */
  33
  34 mlt_frame mlt_frame_init( mlt_service service )
  35 {
  36         // Allocate a frame
  37         mlt_frame this = calloc( sizeof( struct mlt_frame_s ), 1 );
  38
  39         if ( this != NULL )
  40         {
  41                 mlt_profile profile = mlt_service_profile( service );
  42
  43                 // Initialise the properties
  44                 mlt_properties properties = &this->parent;
  45                 mlt_properties_init( properties, this );
  46
  47                 // Set default properties on the frame
  48                 mlt_properties_set_position( properties, "_position", 0.0 );
  49                 mlt_properties_set_data( properties, "image", NULL, 0, NULL, NULL );
  50                 mlt_properties_set_int( properties, "width", profile? profile->width : 720 );
  51                 mlt_properties_set_int( properties, "height", profile? profile->height : 576 );
  52                 mlt_properties_set_int( properties, "normalised_width", profile? profile->width : 720 );
  53                 mlt_properties_set_int( properties, "normalised_height", profile? profile->height : 576 );
  54                 mlt_properties_set_double( properties, "aspect_ratio", mlt_profile_sar( NULL ) );
  55                 mlt_properties_set_data( properties, "audio", NULL, 0, NULL, NULL );
  56                 mlt_properties_set_data( properties, "alpha", NULL, 0, NULL, NULL );
  57
  58                 // Construct stacks for frames and methods
  59                 this->stack_image = mlt_deque_init( );
  60                 this->stack_audio = mlt_deque_init( );
  61                 this->stack_service = mlt_deque_init( );
  62         }
  63
  64         return this;
  65 }
  66
  67 /** Fetch the frames properties.
  68 */
  69
  70 mlt_properties mlt_frame_properties( mlt_frame this )
  71 {
  72         return this != NULL ? &this->parent : NULL;
  73 }
  74
  75 /** Check if we have a way to derive something other than a test card.
  76 */
  77
  78 int mlt_frame_is_test_card( mlt_frame this )
  79 {
  80         return mlt_deque_count( this->stack_image ) == 0 || mlt_properties_get_int( MLT_FRAME_PROPERTIES( this ), "test_image" );
  81 }
  82
  83 /** Check if we have a way to derive something other than test audio.
  84 */
  85
  86 int mlt_frame_is_test_audio( mlt_frame this )
  87 {
  88         return mlt_deque_count( this->stack_audio ) == 0 || mlt_properties_get_int( MLT_FRAME_PROPERTIES( this ), "test_audio" );
  89 }
  90
  91 /** Get the aspect ratio of the frame.
  92 */
  93
  94 double mlt_frame_get_aspect_ratio( mlt_frame this )
  95 {
  96         return mlt_properties_get_double( MLT_FRAME_PROPERTIES( this ), "aspect_ratio" );
  97 }
  98
  99 /** Set the aspect ratio of the frame.
 100 */
 101
 102 int mlt_frame_set_aspect_ratio( mlt_frame this, double value )
 103 {
 104         return mlt_properties_set_double( MLT_FRAME_PROPERTIES( this ), "aspect_ratio", value );
 105 }
 106
 107 /** Get the position of this frame.
 108 */
 109
 110 mlt_position mlt_frame_get_position( mlt_frame this )
 111 {
 112         int pos = mlt_properties_get_position( MLT_FRAME_PROPERTIES( this ), "_position" );
 113         return pos < 0 ? 0 : pos;
 114 }
 115
 116 /** Set the position of this frame.
 117 */
 118
 119 int mlt_frame_set_position( mlt_frame this, mlt_position value )
 120 {
 121         return mlt_properties_set_position( MLT_FRAME_PROPERTIES( this ), "_position", value );
 122 }
 123
 124 /** Stack a get_image callback.
 125 */
 126
 127 int mlt_frame_push_get_image( mlt_frame this, mlt_get_image get_image )
 128 {
 129         return mlt_deque_push_back( this->stack_image, get_image );
 130 }
 131
 132 /** Pop a get_image callback.
 133 */
 134
 135 mlt_get_image mlt_frame_pop_get_image( mlt_frame this )
 136 {
 137         return mlt_deque_pop_back( this->stack_image );
 138 }
 139
 140 /** Push a frame.
 141 */
 142
 143 int mlt_frame_push_frame( mlt_frame this, mlt_frame that )
 144 {
 145         return mlt_deque_push_back( this->stack_image, that );
 146 }
 147
 148 /** Pop a frame.
 149 */
 150
 151 mlt_frame mlt_frame_pop_frame( mlt_frame this )
 152 {
 153         return mlt_deque_pop_back( this->stack_image );
 154 }
 155
 156 /** Push a service.
 157 */
 158
 159 int mlt_frame_push_service( mlt_frame this, void *that )
 160 {
 161         return mlt_deque_push_back( this->stack_image, that );
 162 }
 163
 164 /** Pop a service.
 165 */
 166
 167 void *mlt_frame_pop_service( mlt_frame this )
 168 {
 169         return mlt_deque_pop_back( this->stack_image );
 170 }
 171
 172 /** Push a service.
 173 */
 174
 175 int mlt_frame_push_service_int( mlt_frame this, int that )
 176 {
 177         return mlt_deque_push_back_int( this->stack_image, that );
 178 }
 179
 180 /** Pop a service.
 181 */
 182
 183 int mlt_frame_pop_service_int( mlt_frame this )
 184 {
 185         return mlt_deque_pop_back_int( this->stack_image );
 186 }
 187
 188 /** Push an audio item on the stack.
 189 */
 190
 191 int mlt_frame_push_audio( mlt_frame this, void *that )
 192 {
 193         return mlt_deque_push_back( this->stack_audio, that );
 194 }
 195
 196 /** Pop an audio item from the stack
 197 */
 198
 199 void *mlt_frame_pop_audio( mlt_frame this )
 200 {
 201         return mlt_deque_pop_back( this->stack_audio );
 202 }
 203
 204 /** Return the service stack
 205 */
 206
 207 mlt_deque mlt_frame_service_stack( mlt_frame this )
 208 {
 209         return this->stack_service;
 210 }
 211
 212 /** Replace image stack with the information provided.
 213
 214         This might prove to be unreliable and restrictive - the idea is that a transition
 215         which normally uses two images may decide to only use the b frame (ie: in the case
 216         of a composite where the b frame completely obscures the a frame).
 217
 218         The image must be writable and the destructor for the image itself must be taken
 219         care of on another frame and that frame cannot have a replace applied to it...
 220         Further it assumes that no alpha mask is in use.
 221
 222         For these reasons, it can only be used in a specific situation - when you have
 223         multiple tracks each with their own transition and these transitions are applied
 224         in a strictly reversed order (ie: highest numbered [lowest track] is processed
 225         first).
 226
 227         More reliable approach - the cases should be detected during the process phase
 228         and the upper tracks should simply not be invited to stack...
 229 */
 230
 231 void mlt_frame_replace_image( mlt_frame this, uint8_t *image, mlt_image_format format, int width, int height )
 232 {
 233         // Remove all items from the stack
 234         while( mlt_deque_pop_back( this->stack_image ) ) ;
 235
 236         // Update the information
 237         mlt_properties_set_data( MLT_FRAME_PROPERTIES( this ), "image", image, 0, NULL, NULL );
 238         mlt_properties_set_int( MLT_FRAME_PROPERTIES( this ), "width", width );
 239         mlt_properties_set_int( MLT_FRAME_PROPERTIES( this ), "height", height );
 240         mlt_properties_set_int( MLT_FRAME_PROPERTIES( this ), "format", format );
 241         this->get_alpha_mask = NULL;
 242 }
 243
 244 /** Get the image associated to the frame.
 245 */
 246
 247 int mlt_frame_get_image( mlt_frame this, uint8_t **buffer, mlt_image_format *format, int *width, int *height, int writable )
 248 {
 249         mlt_properties properties = MLT_FRAME_PROPERTIES( this );
 250         mlt_get_image get_image = mlt_frame_pop_get_image( this );
 251         mlt_producer producer = mlt_properties_get_data( properties, "test_card_producer", NULL );
 252         int error = 0;
 253
 254         if ( get_image != NULL )
 255         {
 256                 mlt_properties_set_int( properties, "image_count", mlt_properties_get_int( properties, "image_count" ) - 1 );
 257                 mlt_position position = mlt_frame_get_position( this );
 258                 error = get_image( this, buffer, format, width, height, writable );
 259                 mlt_properties_set_int( properties, "width", *width );
 260                 mlt_properties_set_int( properties, "height", *height );
 261                 mlt_properties_set_int( properties, "format", *format );
 262                 mlt_frame_set_position( this, position );
 263         }
 264         else if ( mlt_properties_get_data( properties, "image", NULL ) != NULL )
 265         {
 266                 *format = mlt_properties_get_int( properties, "format" );
 267                 *buffer = mlt_properties_get_data( properties, "image", NULL );
 268                 *width = mlt_properties_get_int( properties, "width" );
 269                 *height = mlt_properties_get_int( properties, "height" );
 270         }
 271         else if ( producer != NULL )
 272         {
 273                 mlt_frame test_frame = NULL;
 274                 mlt_service_get_frame( MLT_PRODUCER_SERVICE( producer ), &test_frame, 0 );
 275                 if ( test_frame != NULL )
 276                 {
 277                         mlt_properties test_properties = MLT_FRAME_PROPERTIES( test_frame );
 278                         mlt_properties_set_double( test_properties, "consumer_aspect_ratio", mlt_properties_get_double( properties, "consumer_aspect_ratio" ) );
 279                         mlt_properties_set( test_properties, "rescale.interp", mlt_properties_get( properties, "rescale.interp" ) );
 280                         mlt_frame_get_image( test_frame, buffer, format, width, height, writable );
 281                         mlt_properties_set_data( properties, "test_card_frame", test_frame, 0, ( mlt_destructor )mlt_frame_close, NULL );
 282                         mlt_properties_set_data( properties, "image", *buffer, *width * *height * 2, NULL, NULL );
 283                         mlt_properties_set_int( properties, "width", *width );
 284                         mlt_properties_set_int( properties, "height", *height );
 285                         mlt_properties_set_int( properties, "format", *format );
 286                         mlt_properties_set_double( properties, "aspect_ratio", mlt_frame_get_aspect_ratio( test_frame ) );
 287                 }
 288                 else
 289                 {
 290                         mlt_properties_set_data( properties, "test_card_producer", NULL, 0, NULL, NULL );
 291                         mlt_frame_get_image( this, buffer, format, width, height, writable );
 292                 }
 293         }
 294         else
 295         {
 296                 register uint8_t *p;
 297                 register uint8_t *q;
 298                 int size = 0;
 299
 300                 *width = *width == 0 ? 720 : *width;
 301                 *height = *height == 0 ? 576 : *height;
 302                 size = *width * *height;
 303
 304                 mlt_properties_set_int( properties, "format", *format );
 305                 mlt_properties_set_int( properties, "width", *width );
 306                 mlt_properties_set_int( properties, "height", *height );
 307                 mlt_properties_set_int( properties, "aspect_ratio", 0 );
 308
 309                 switch( *format )
 310                 {
 311                         case mlt_image_none:
 312                                 size = 0;
 313                                 *buffer = NULL;
 314                                 break;
 315                         case mlt_image_rgb24:
 316                                 size *= 3;
 317                                 size += *width * 3;
 318                                 *buffer = mlt_pool_alloc( size );
 319                                 if ( *buffer )
 320                                         memset( *buffer, 255, size );
 321                                 break;
 322                         case mlt_image_rgb24a:
 323                         case mlt_image_opengl:
 324                                 size *= 4;
 325                                 size += *width * 4;
 326                                 *buffer = mlt_pool_alloc( size );
 327                                 if ( *buffer )
 328                                         memset( *buffer, 255, size );
 329                                 break;
 330                         case mlt_image_yuv422:
 331                                 size *= 2;
 332                                 size += *width * 2;
 333                                 *buffer = mlt_pool_alloc( size );
 334                                 p = *buffer;
 335                                 q = p + size;
 336                                 while ( p != NULL && p != q )
 337                                 {
 338                                         *p ++ = 235;
 339                                         *p ++ = 128;
 340                                 }
 341                                 break;
 342                         case mlt_image_yuv420p:
 343                                 size = size * 3 / 2;
 344                                 *buffer = mlt_pool_alloc( size );
 345                                 if ( *buffer )
 346                                         memset( *buffer, 255, size );
 347                                 break;
 348                 }
 349
 350                 mlt_properties_set_data( properties, "image", *buffer, size, ( mlt_destructor )mlt_pool_release, NULL );
 351                 mlt_properties_set_int( properties, "test_image", 1 );
 352         }
 353
 354         mlt_properties_set_int( properties, "scaled_width", *width );
 355         mlt_properties_set_int( properties, "scaled_height", *height );
 356
 357         return error;
 358 }
 359
 360 uint8_t *mlt_frame_get_alpha_mask( mlt_frame this )
 361 {
 362         uint8_t *alpha = NULL;
 363         if ( this != NULL )
 364         {
 365                 if ( this->get_alpha_mask != NULL )
 366                         alpha = this->get_alpha_mask( this );
 367                 if ( alpha == NULL )
 368                         alpha = mlt_properties_get_data( &this->parent, "alpha", NULL );
 369                 if ( alpha == NULL )
 370                 {
 371                         int size = mlt_properties_get_int( &this->parent, "scaled_width" ) * mlt_properties_get_int( &this->parent, "scaled_height" );
 372                         alpha = mlt_pool_alloc( size );
 373                         memset( alpha, 255, size );
 374                         mlt_properties_set_data( &this->parent, "alpha", alpha, size, mlt_pool_release, NULL );
 375                 }
 376         }
 377         return alpha;
 378 }
 379
 380 int mlt_frame_get_audio( mlt_frame this, int16_t **buffer, mlt_audio_format *format, int *frequency, int *channels, int *samples )
 381 {
 382         mlt_get_audio get_audio = mlt_frame_pop_audio( this );
 383         mlt_properties properties = MLT_FRAME_PROPERTIES( this );
 384         int hide = mlt_properties_get_int( properties, "test_audio" );
 385
 386         if ( hide == 0 && get_audio != NULL )
 387         {
 388                 mlt_position position = mlt_frame_get_position( this );
 389                 get_audio( this, buffer, format, frequency, channels, samples );
 390                 mlt_frame_set_position( this, position );
 391         }
 392         else if ( mlt_properties_get_data( properties, "audio", NULL ) )
 393         {
 394                 *buffer = mlt_properties_get_data( properties, "audio", NULL );
 395                 *frequency = mlt_properties_get_int( properties, "audio_frequency" );
 396                 *channels = mlt_properties_get_int( properties, "audio_channels" );
 397                 *samples = mlt_properties_get_int( properties, "audio_samples" );
 398         }
 399         else
 400         {
 401                 int size = 0;
 402                 *samples = *samples <= 0 ? 1920 : *samples;
 403                 *channels = *channels <= 0 ? 2 : *channels;
 404                 *frequency = *frequency <= 0 ? 48000 : *frequency;
 405                 size = *samples * *channels * sizeof( int16_t );
 406                 *buffer = mlt_pool_alloc( size );
 407                 if ( *buffer != NULL )
 408                         memset( *buffer, 0, size );
 409                 mlt_properties_set_data( properties, "audio", *buffer, size, ( mlt_destructor )mlt_pool_release, NULL );
 410                 mlt_properties_set_int( properties, "test_audio", 1 );
 411         }
 412
 413         mlt_properties_set_int( properties, "audio_frequency", *frequency );
 414         mlt_properties_set_int( properties, "audio_channels", *channels );
 415         mlt_properties_set_int( properties, "audio_samples", *samples );
 416
 417         if ( mlt_properties_get( properties, "meta.volume" ) )
 418         {
 419                 double value = mlt_properties_get_double( properties, "meta.volume" );
 420
 421                 if ( value == 0.0 )
 422                 {
 423                         memset( *buffer, 0, *samples * *channels * 2 );
 424                 }
 425                 else if ( value != 1.0 )
 426                 {
 427                         int total = *samples * *channels;
 428                         int16_t *p = *buffer;
 429                         while ( total -- )
 430                         {
 431                                 *p = *p * value;
 432                                 p ++;
 433                         }
 434                 }
 435
 436                 mlt_properties_set( properties, "meta.volume", NULL );
 437         }
 438
 439         return 0;
 440 }
 441
 442 unsigned char *mlt_frame_get_waveform( mlt_frame this, int w, int h )
 443 {
 444         int16_t *pcm = NULL;
 445         mlt_properties properties = MLT_FRAME_PROPERTIES( this );
 446         mlt_audio_format format = mlt_audio_pcm;
 447         int frequency = 32000; // lower frequency available?
 448         int channels = 2;
 449         double fps = mlt_profile_fps( NULL );
 450         int samples = mlt_sample_calculator( fps, frequency, mlt_frame_get_position( this ) );
 451
 452         // Get the pcm data
 453         mlt_frame_get_audio( this, &pcm, &format, &frequency, &channels, &samples );
 454
 455         // Make an 8-bit buffer large enough to hold rendering
 456         int size = w * h;
 457         unsigned char *bitmap = ( unsigned char* )mlt_pool_alloc( size );
 458         if ( bitmap != NULL )
 459                 memset( bitmap, 0, size );
 460         mlt_properties_set_data( properties, "waveform", bitmap, size, ( mlt_destructor )mlt_pool_release, NULL );
 461
 462         // Render vertical lines
 463         int16_t *ubound = pcm + samples * channels;
 464         int skip = samples / w - 1;
 465         int i, j, k;
 466
 467         // Iterate sample stream and along x coordinate
 468         for ( i = 0; i < w && pcm < ubound; i++ )
 469         {
 470                 // pcm data has channels interleaved
 471                 for ( j = 0; j < channels; j++ )
 472                 {
 473                         // Determine sample's magnitude from 2s complement;
 474                         int pcm_magnitude = *pcm < 0 ? ~(*pcm) + 1 : *pcm;
 475                         // The height of a line is the ratio of the magnitude multiplied by
 476                         // half the vertical resolution
 477                         int height = ( int )( ( double )( pcm_magnitude ) / 32768 * h / 2 );
 478                         // Determine the starting y coordinate - left channel above center,
 479                         // right channel below - currently assumes 2 channels
 480                         int displacement = ( h / 2 ) - ( 1 - j ) * height;
 481                         // Position buffer pointer using y coordinate, stride, and x coordinate
 482                         unsigned char *p = &bitmap[ i + displacement * w ];
 483
 484                         // Draw vertical line
 485                         for ( k = 0; k < height; k++ )
 486                                 p[ w * k ] = 0xFF;
 487
 488                         pcm++;
 489                 }
 490                 pcm += skip * channels;
 491         }
 492
 493         return bitmap;
 494 }
 495
 496 mlt_producer mlt_frame_get_original_producer( mlt_frame this )
 497 {
 498         if ( this != NULL )
 499                 return mlt_properties_get_data( MLT_FRAME_PROPERTIES( this ), "_producer", NULL );
 500         return NULL;
 501 }
 502
 503 void mlt_frame_close( mlt_frame this )
 504 {
 505         if ( this != NULL && mlt_properties_dec_ref( MLT_FRAME_PROPERTIES( this ) ) <= 0 )
 506         {
 507                 mlt_deque_close( this->stack_image );
 508                 mlt_deque_close( this->stack_audio );
 509                 while( mlt_deque_peek_back( this->stack_service ) )
 510                         mlt_service_close( mlt_deque_pop_back( this->stack_service ) );
 511                 mlt_deque_close( this->stack_service );
 512                 mlt_properties_close( &this->parent );
 513                 free( this );
 514         }
 515 }
 516
 517 /***** convenience functions *****/
 518
 519 int mlt_convert_yuv422_to_rgb24a( uint8_t *yuv, uint8_t *rgba, unsigned int total )
 520 {
 521         int ret = 0;
 522         int yy, uu, vv;
 523         int r,g,b;
 524         total /= 2;
 525         while (total--)
 526         {
 527                 yy = yuv[0];
 528                 uu = yuv[1];
 529                 vv = yuv[3];
 530                 YUV2RGB(yy, uu, vv, r, g, b);
 531                 rgba[0] = r;
 532                 rgba[1] = g;
 533                 rgba[2] = b;
 534                 rgba[3] = 255;
 535                 yy = yuv[2];
 536                 YUV2RGB(yy, uu, vv, r, g, b);
 537                 rgba[4] = r;
 538                 rgba[5] = g;
 539                 rgba[6] = b;
 540                 rgba[7] = 255;
 541                 yuv += 4;
 542                 rgba += 8;
 543         }
 544         return ret;
 545 }
 546
 547 int mlt_convert_rgb24a_to_yuv422( uint8_t *rgba, int width, int height, int stride, uint8_t *yuv, uint8_t *alpha )
 548 {
 549         int ret = 0;
 550         register int y0, y1, u0, u1, v0, v1;
 551         register int r, g, b;
 552         register uint8_t *d = yuv;
 553         register int i, j;
 554
 555         if ( alpha )
 556         for ( i = 0; i < height; i++ )
 557         {
 558                 register uint8_t *s = rgba + ( stride * i );
 559                 for ( j = 0; j < ( width / 2 ); j++ )
 560                 {
 561                         r = *s++;
 562                         g = *s++;
 563                         b = *s++;
 564                         *alpha++ = *s++;
 565                         RGB2YUV (r, g, b, y0, u0 , v0);
 566                         r = *s++;
 567                         g = *s++;
 568                         b = *s++;
 569                         *alpha++ = *s++;
 570                         RGB2YUV (r, g, b, y1, u1 , v1);
 571                         *d++ = y0;
 572                         *d++ = (u0+u1) >> 1;
 573                         *d++ = y1;
 574                         *d++ = (v0+v1) >> 1;
 575                 }
 576                 if ( width % 2 )
 577                 {
 578                         r = *s++;
 579                         g = *s++;
 580                         b = *s++;
 581                         *alpha++ = *s++;
 582                         RGB2YUV (r, g, b, y0, u0 , v0);
 583                         *d++ = y0;
 584                         *d++ = u0;
 585                 }
 586         }
 587         else
 588         for ( i = 0; i < height; i++ )
 589         {
 590                 register uint8_t *s = rgba + ( stride * i );
 591                 for ( j = 0; j < ( width / 2 ); j++ )
 592                 {
 593                         r = *s++;
 594                         g = *s++;
 595                         b = *s++;
 596                         s++;
 597                         RGB2YUV (r, g, b, y0, u0 , v0);
 598                         r = *s++;
 599                         g = *s++;
 600                         b = *s++;
 601                         s++;
 602                         RGB2YUV (r, g, b, y1, u1 , v1);
 603                         *d++ = y0;
 604                         *d++ = (u0+u1) >> 1;
 605                         *d++ = y1;
 606                         *d++ = (v0+v1) >> 1;
 607                 }
 608                 if ( width % 2 )
 609                 {
 610                         r = *s++;
 611                         g = *s++;
 612                         b = *s++;
 613                         s++;
 614                         RGB2YUV (r, g, b, y0, u0 , v0);
 615                         *d++ = y0;
 616                         *d++ = u0;
 617                 }
 618         }
 619
 620         return ret;
 621 }
 622
 623 int mlt_convert_rgb24_to_yuv422( uint8_t *rgb, int width, int height, int stride, uint8_t *yuv )
 624 {
 625         int ret = 0;
 626         register int y0, y1, u0, u1, v0, v1;
 627         register int r, g, b;
 628         register uint8_t *d = yuv;
 629         register int i, j;
 630
 631         for ( i = 0; i < height; i++ )
 632         {
 633                 register uint8_t *s = rgb + ( stride * i );
 634                 for ( j = 0; j < ( width / 2 ); j++ )
 635                 {
 636                         r = *s++;
 637                         g = *s++;
 638                         b = *s++;
 639                         RGB2YUV (r, g, b, y0, u0 , v0);
 640                         r = *s++;
 641                         g = *s++;
 642                         b = *s++;
 643                         RGB2YUV (r, g, b, y1, u1 , v1);
 644                         *d++ = y0;
 645                         *d++ = (u0+u1) >> 1;
 646                         *d++ = y1;
 647                         *d++ = (v0+v1) >> 1;
 648                 }
 649                 if ( width % 2 )
 650                 {
 651                         r = *s++;
 652                         g = *s++;
 653                         b = *s++;
 654                         RGB2YUV (r, g, b, y0, u0 , v0);
 655                         *d++ = y0;
 656                         *d++ = u0;
 657                 }
 658         }
 659         return ret;
 660 }
 661
 662 int mlt_convert_bgr24a_to_yuv422( uint8_t *rgba, int width, int height, int stride, uint8_t *yuv, uint8_t *alpha )
 663 {
 664         int ret = 0;
 665         register int y0, y1, u0, u1, v0, v1;
 666         register int r, g, b;
 667         register uint8_t *d = yuv;
 668         register int i, j;
 669
 670         if ( alpha )
 671         for ( i = 0; i < height; i++ )
 672         {
 673                 register uint8_t *s = rgba + ( stride * i );
 674                 for ( j = 0; j < ( width / 2 ); j++ )
 675                 {
 676                         b = *s++;
 677                         g = *s++;
 678                         r = *s++;
 679                         *alpha++ = *s++;
 680                         RGB2YUV (r, g, b, y0, u0 , v0);
 681                         b = *s++;
 682                         g = *s++;
 683                         r = *s++;
 684                         *alpha++ = *s++;
 685                         RGB2YUV (r, g, b, y1, u1 , v1);
 686                         *d++ = y0;
 687                         *d++ = (u0+u1) >> 1;
 688                         *d++ = y1;
 689                         *d++ = (v0+v1) >> 1;
 690                 }
 691                 if ( width % 2 )
 692                 {
 693                         b = *s++;
 694                         g = *s++;
 695                         r = *s++;
 696                         *alpha++ = *s++;
 697                         RGB2YUV (r, g, b, y0, u0 , v0);
 698                         *d++ = y0;
 699                         *d++ = u0;
 700                 }
 701         }
 702         else
 703         for ( i = 0; i < height; i++ )
 704         {
 705                 register uint8_t *s = rgba + ( stride * i );
 706                 for ( j = 0; j < ( width / 2 ); j++ )
 707                 {
 708                         b = *s++;
 709                         g = *s++;
 710                         r = *s++;
 711                         s++;
 712                         RGB2YUV (r, g, b, y0, u0 , v0);
 713                         b = *s++;
 714                         g = *s++;
 715                         r = *s++;
 716                         s++;
 717                         RGB2YUV (r, g, b, y1, u1 , v1);
 718                         *d++ = y0;
 719                         *d++ = (u0+u1) >> 1;
 720                         *d++ = y1;
 721                         *d++ = (v0+v1) >> 1;
 722                 }
 723                 if ( width % 2 )
 724                 {
 725                         b = *s++;
 726                         g = *s++;
 727                         r = *s++;
 728                         s++;
 729                         RGB2YUV (r, g, b, y0, u0 , v0);
 730                         *d++ = y0;
 731                         *d++ = u0;
 732                 }
 733         }
 734         return ret;
 735 }
 736
 737 int mlt_convert_bgr24_to_yuv422( uint8_t *rgb, int width, int height, int stride, uint8_t *yuv )
 738 {
 739         int ret = 0;
 740         register int y0, y1, u0, u1, v0, v1;
 741         register int r, g, b;
 742         register uint8_t *d = yuv;
 743         register int i, j;
 744
 745         for ( i = 0; i < height; i++ )
 746         {
 747                 register uint8_t *s = rgb + ( stride * i );
 748                 for ( j = 0; j < ( width / 2 ); j++ )
 749                 {
 750                         b = *s++;
 751                         g = *s++;
 752                         r = *s++;
 753                         RGB2YUV (r, g, b, y0, u0 , v0);
 754                         b = *s++;
 755                         g = *s++;
 756                         r = *s++;
 757                         RGB2YUV (r, g, b, y1, u1 , v1);
 758                         *d++ = y0;
 759                         *d++ = (u0+u1) >> 1;
 760                         *d++ = y1;
 761                         *d++ = (v0+v1) >> 1;
 762                 }
 763                 if ( width % 2 )
 764                 {
 765                         b = *s++;
 766                         g = *s++;
 767                         r = *s++;
 768                         RGB2YUV (r, g, b, y0, u0 , v0);
 769                         *d++ = y0;
 770                         *d++ = u0;
 771                 }
 772         }
 773         return ret;
 774 }
 775
 776 int mlt_convert_argb_to_yuv422( uint8_t *rgba, int width, int height, int stride, uint8_t *yuv, uint8_t *alpha )
 777 {
 778         int ret = 0;
 779         register int y0, y1, u0, u1, v0, v1;
 780         register int r, g, b;
 781         register uint8_t *d = yuv;
 782         register int i, j;
 783
 784         if ( alpha )
 785         for ( i = 0; i < height; i++ )
 786         {
 787                 register uint8_t *s = rgba + ( stride * i );
 788                 for ( j = 0; j < ( width / 2 ); j++ )
 789                 {
 790                         *alpha++ = *s++;
 791                         r = *s++;
 792                         g = *s++;
 793                         b = *s++;
 794                         RGB2YUV (r, g, b, y0, u0 , v0);
 795                         *alpha++ = *s++;
 796                         r = *s++;
 797                         g = *s++;
 798                         b = *s++;
 799                         RGB2YUV (r, g, b, y1, u1 , v1);
 800                         *d++ = y0;
 801                         *d++ = (u0+u1) >> 1;
 802                         *d++ = y1;
 803                         *d++ = (v0+v1) >> 1;
 804                 }
 805                 if ( width % 2 )
 806                 {
 807                         *alpha++ = *s++;
 808                         r = *s++;
 809                         g = *s++;
 810                         b = *s++;
 811                         RGB2YUV (r, g, b, y0, u0 , v0);
 812                         *d++ = y0;
 813                         *d++ = u0;
 814                 }
 815         }
 816         else
 817         for ( i = 0; i < height; i++ )
 818         {
 819                 register uint8_t *s = rgba + ( stride * i );
 820                 for ( j = 0; j < ( width / 2 ); j++ )
 821                 {
 822                         s++;
 823                         r = *s++;
 824                         g = *s++;
 825                         b = *s++;
 826                         RGB2YUV (r, g, b, y0, u0 , v0);
 827                         s++;
 828                         r = *s++;
 829                         g = *s++;
 830                         b = *s++;
 831                         RGB2YUV (r, g, b, y1, u1 , v1);
 832                         *d++ = y0;
 833                         *d++ = (u0+u1) >> 1;
 834                         *d++ = y1;
 835                         *d++ = (v0+v1) >> 1;
 836                 }
 837                 if ( width % 2 )
 838                 {
 839                         s++;
 840                         r = *s++;
 841                         g = *s++;
 842                         b = *s++;
 843                         RGB2YUV (r, g, b, y0, u0 , v0);
 844                         *d++ = y0;
 845                         *d++ = u0;
 846                 }
 847         }
 848         return ret;
 849 }
 850
 851 int mlt_convert_yuv420p_to_yuv422( uint8_t *yuv420p, int width, int height, int stride, uint8_t *yuv )
 852 {
 853         int ret = 0;
 854         register int i, j;
 855
 856         int half = width >> 1;
 857
 858         uint8_t *Y = yuv420p;
 859         uint8_t *U = Y + width * height;
 860         uint8_t *V = U + width * height / 4;
 861
 862         register uint8_t *d = yuv;
 863
 864         for ( i = 0; i < height; i++ )
 865         {
 866                 register uint8_t *u = U + ( i / 2 ) * ( half );
 867                 register uint8_t *v = V + ( i / 2 ) * ( half );
 868
 869                 for ( j = 0; j < half; j++ )
 870                 {
 871                         *d ++ = *Y ++;
 872                         *d ++ = *u ++;
 873                         *d ++ = *Y ++;
 874                         *d ++ = *v ++;
 875                 }
 876         }
 877         return ret;
 878 }
 879
 880 uint8_t *mlt_resize_alpha( uint8_t *input, int owidth, int oheight, int iwidth, int iheight, uint8_t alpha_value )
 881 {
 882         uint8_t *output = NULL;
 883
 884         if ( input != NULL && ( iwidth != owidth || iheight != oheight ) && ( owidth > 6 && oheight > 6 ) )
 885         {
 886                 uint8_t *out_line;
 887                 int offset_x = ( owidth - iwidth ) / 2;
 888                 int offset_y = ( oheight - iheight ) / 2;
 889                 int iused = iwidth;
 890
 891                 output = mlt_pool_alloc( owidth * oheight );
 892                 memset( output, alpha_value, owidth * oheight );
 893
 894                 offset_x -= offset_x % 2;
 895
 896                 out_line = output + offset_y * owidth;
 897                 out_line += offset_x;
 898
 899                 // Loop for the entirety of our output height.
 900                 while ( iheight -- )
 901                 {
 902                         // We're in the input range for this row.
 903                         memcpy( out_line, input, iused );
 904
 905                         // Move to next input line
 906                         input += iwidth;
 907
 908                 // Move to next output line
 909                 out_line += owidth;
 910                 }
 911         }
 912
 913         return output;
 914 }
 915
 916 void mlt_resize_yuv422( uint8_t *output, int owidth, int oheight, uint8_t *input, int iwidth, int iheight )
 917 {
 918         // Calculate strides
 919         int istride = iwidth * 2;
 920         int ostride = owidth * 2;
 921         int offset_x = ( owidth - iwidth );
 922         int offset_y = ( oheight - iheight ) / 2;
 923         uint8_t *in_line = input;
 924         uint8_t *out_line;
 925         int size = owidth * oheight;
 926         uint8_t *p = output;
 927
 928         // Optimisation point
 929         if ( output == NULL || input == NULL || ( owidth <= 6 || oheight <= 6 || iwidth <= 6 || oheight <= 6 ) )
 930         {
 931                 return;
 932         }
 933         else if ( iwidth == owidth && iheight == oheight )
 934         {
 935                 memcpy( output, input, iheight * istride );
 936                 return;
 937         }
 938
 939         while( size -- )
 940         {
 941                 *p ++ = 16;
 942                 *p ++ = 128;
 943         }
 944
 945         offset_x -= offset_x % 4;
 946
 947         out_line = output + offset_y * ostride;
 948         out_line += offset_x;
 949
 950         // Loop for the entirety of our output height.
 951         while ( iheight -- )
 952         {
 953                 // We're in the input range for this row.
 954                 memcpy( out_line, in_line, iwidth * 2 );
 955
 956                 // Move to next input line
 957                 in_line += istride;
 958
 959                 // Move to next output line
 960                 out_line += ostride;
 961         }
 962 }
 963
 964 /** A resizing function for yuv422 frames - this does not rescale, but simply
 965         resizes. It assumes yuv422 images available on the frame so use with care.
 966 */
 967
 968 uint8_t *mlt_frame_resize_yuv422( mlt_frame this, int owidth, int oheight )
 969 {
 970         // Get properties
 971         mlt_properties properties = MLT_FRAME_PROPERTIES( this );
 972
 973         // Get the input image, width and height
 974         uint8_t *input = mlt_properties_get_data( properties, "image", NULL );
 975         uint8_t *alpha = mlt_frame_get_alpha_mask( this );
 976
 977         int iwidth = mlt_properties_get_int( properties, "width" );
 978         int iheight = mlt_properties_get_int( properties, "height" );
 979
 980         // If width and height are correct, don't do anything
 981         if ( iwidth != owidth || iheight != oheight )
 982         {
 983                 uint8_t alpha_value = mlt_properties_get_int( properties, "resize_alpha" );
 984
 985                 // Create the output image
 986                 uint8_t *output = mlt_pool_alloc( owidth * ( oheight + 1 ) * 2 );
 987
 988                 // Call the generic resize
 989                 mlt_resize_yuv422( output, owidth, oheight, input, iwidth, iheight );
 990
 991                 // Now update the frame
 992                 mlt_properties_set_data( properties, "image", output, owidth * ( oheight + 1 ) * 2, ( mlt_destructor )mlt_pool_release, NULL );
 993                 mlt_properties_set_int( properties, "width", owidth );
 994                 mlt_properties_set_int( properties, "height", oheight );
 995
 996                 // We should resize the alpha too
 997                 alpha = mlt_resize_alpha( alpha, owidth, oheight, iwidth, iheight, alpha_value );
 998                 if ( alpha != NULL )
 999                 {
1000                         mlt_properties_set_data( properties, "alpha", alpha, owidth * oheight, ( mlt_destructor )mlt_pool_release, NULL );
1001                         this->get_alpha_mask = NULL;
1002                 }
1003
1004                 // Return the output
1005                 return output;
1006         }
1007         // No change, return input
1008         return input;
1009 }
1010
1011 /** A rescaling function for yuv422 frames - low quality, and provided for testing
1012         only. It assumes yuv422 images available on the frame so use with care.
1013 */
1014
1015 uint8_t *mlt_frame_rescale_yuv422( mlt_frame this, int owidth, int oheight )
1016 {
1017         // Get properties
1018         mlt_properties properties = MLT_FRAME_PROPERTIES( this );
1019
1020         // Get the input image, width and height
1021         uint8_t *input = mlt_properties_get_data( properties, "image", NULL );
1022         int iwidth = mlt_properties_get_int( properties, "width" );
1023         int iheight = mlt_properties_get_int( properties, "height" );
1024
1025         // If width and height are correct, don't do anything
1026         if ( iwidth != owidth || iheight != oheight )
1027         {
1028                 // Create the output image
1029                 uint8_t *output = mlt_pool_alloc( owidth * ( oheight + 1 ) * 2 );
1030
1031                 // Calculate strides
1032                 int istride = iwidth * 2;
1033                 int ostride = owidth * 2;
1034
1035                 iwidth = iwidth - ( iwidth % 4 );
1036
1037                 // Derived coordinates
1038                 int dy, dx;
1039
1040         // Calculate ranges
1041         int out_x_range = owidth / 2;
1042         int out_y_range = oheight / 2;
1043         int in_x_range = iwidth / 2;
1044         int in_y_range = iheight / 2;
1045
1046         // Output pointers
1047         register uint8_t *out_line = output;
1048         register uint8_t *out_ptr;
1049
1050         // Calculate a middle pointer
1051         uint8_t *in_middle = input + istride * in_y_range + in_x_range * 2;
1052         uint8_t *in_line;
1053
1054                 // Generate the affine transform scaling values
1055                 register int scale_width = ( iwidth << 16 ) / owidth;
1056                 register int scale_height = ( iheight << 16 ) / oheight;
1057                 register int base = 0;
1058
1059                 int outer = out_x_range * scale_width;
1060                 int bottom = out_y_range * scale_height;
1061
1062         // Loop for the entirety of our output height.
1063         for ( dy = - bottom; dy < bottom; dy += scale_height )
1064         {
1065                 // Start at the beginning of the line
1066                 out_ptr = out_line;
1067
1068                 // Pointer to the middle of the input line
1069                 in_line = in_middle + ( dy >> 16 ) * istride;
1070
1071                 // Loop for the entirety of our output row.
1072                 for ( dx = - outer; dx < outer; dx += scale_width )
1073                 {
1074                                 base = dx >> 15;
1075                                 base &= 0xfffffffe;
1076                                 *out_ptr ++ = *( in_line + base );
1077                                 base &= 0xfffffffc;
1078                                 *out_ptr ++ = *( in_line + base + 1 );
1079                                 dx += scale_width;
1080                                 base = dx >> 15;
1081                                 base &= 0xfffffffe;
1082                                 *out_ptr ++ = *( in_line + base );
1083                                 base &= 0xfffffffc;
1084                                 *out_ptr ++ = *( in_line + base + 3 );
1085                 }
1086
1087                 // Move to next output line
1088                 out_line += ostride;
1089         }
1090
1091                 // Now update the frame
1092                 mlt_properties_set_data( properties, "image", output, owidth * ( oheight + 1 ) * 2, ( mlt_destructor )mlt_pool_release, NULL );
1093                 mlt_properties_set_int( properties, "width", owidth );
1094                 mlt_properties_set_int( properties, "height", oheight );
1095
1096                 // Return the output
1097                 return output;
1098         }
1099
1100         // No change, return input
1101         return input;
1102 }
1103
1104 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 )
1105 {
1106         int ret = 0;
1107         int16_t *src, *dest;
1108         int frequency_src = *frequency, frequency_dest = *frequency;
1109         int channels_src = *channels, channels_dest = *channels;
1110         int samples_src = *samples, samples_dest = *samples;
1111         int i, j;
1112         double d = 0, s = 0;
1113
1114         mlt_frame_get_audio( that, &src, format, &frequency_src, &channels_src, &samples_src );
1115         mlt_frame_get_audio( this, &dest, format, &frequency_dest, &channels_dest, &samples_dest );
1116
1117         int silent = mlt_properties_get_int( MLT_FRAME_PROPERTIES( this ), "silent_audio" );
1118         mlt_properties_set_int( MLT_FRAME_PROPERTIES( this ), "silent_audio", 0 );
1119         if ( silent )
1120                 memset( dest, 0, samples_dest * channels_dest * sizeof( int16_t ) );
1121
1122         silent = mlt_properties_get_int( MLT_FRAME_PROPERTIES( that ), "silent_audio" );
1123         mlt_properties_set_int( MLT_FRAME_PROPERTIES( that ), "silent_audio", 0 );
1124         if ( silent )
1125                 memset( src, 0, samples_src * channels_src * sizeof( int16_t ) );
1126
1127         if ( channels_src > 6 )
1128                 channels_src = 0;
1129         if ( channels_dest > 6 )
1130                 channels_dest = 0;
1131         if ( samples_src > 4000 )
1132                 samples_src = 0;
1133         if ( samples_dest > 4000 )
1134                 samples_dest = 0;
1135
1136         // determine number of samples to process
1137         *samples = samples_src < samples_dest ? samples_src : samples_dest;
1138         *channels = channels_src < channels_dest ? channels_src : channels_dest;
1139         *buffer = dest;
1140         *frequency = frequency_dest;
1141
1142         // Compute a smooth ramp over start to end
1143         float weight = weight_start;
1144         float weight_step = ( weight_end - weight_start ) / *samples;
1145
1146         if ( src == dest )
1147         {
1148                 *samples = samples_src;
1149                 *channels = channels_src;
1150                 *buffer = src;
1151                 *frequency = frequency_src;
1152                 return ret;
1153         }
1154
1155         // Mixdown
1156         for ( i = 0; i < *samples; i++ )
1157         {
1158                 for ( j = 0; j < *channels; j++ )
1159                 {
1160                         if ( j < channels_dest )
1161                                 d = (double) dest[ i * channels_dest + j ];
1162                         if ( j < channels_src )
1163                                 s = (double) src[ i * channels_src + j ];
1164                         dest[ i * channels_dest + j ] = s * weight + d * ( 1.0 - weight );
1165                 }
1166                 weight += weight_step;
1167         }
1168
1169         return ret;
1170 }
1171
1172 // Replacement for broken mlt_frame_audio_mix - this filter uses an inline low pass filter
1173 // to allow mixing without volume hacking
1174 int mlt_frame_combine_audio( mlt_frame this, mlt_frame that, int16_t **buffer, mlt_audio_format *format, int *frequency, int *channels, int *samples )
1175 {
1176         int ret = 0;
1177         int16_t *src, *dest;
1178         int frequency_src = *frequency, frequency_dest = *frequency;
1179         int channels_src = *channels, channels_dest = *channels;
1180         int samples_src = *samples, samples_dest = *samples;
1181         int i, j;
1182         double vp[ 6 ];
1183         double b_weight = 1.0;
1184
1185         if ( mlt_properties_get_int( MLT_FRAME_PROPERTIES( this ), "meta.mixdown" ) )
1186                 b_weight = 1.0 - mlt_properties_get_double( MLT_FRAME_PROPERTIES( this ), "meta.volume" );
1187
1188         mlt_frame_get_audio( that, &src, format, &frequency_src, &channels_src, &samples_src );
1189         mlt_frame_get_audio( this, &dest, format, &frequency_dest, &channels_dest, &samples_dest );
1190
1191         int silent = mlt_properties_get_int( MLT_FRAME_PROPERTIES( this ), "silent_audio" );
1192         mlt_properties_set_int( MLT_FRAME_PROPERTIES( this ), "silent_audio", 0 );
1193         if ( silent )
1194                 memset( dest, 0, samples_dest * channels_dest * sizeof( int16_t ) );
1195
1196         silent = mlt_properties_get_int( MLT_FRAME_PROPERTIES( that ), "silent_audio" );
1197         mlt_properties_set_int( MLT_FRAME_PROPERTIES( that ), "silent_audio", 0 );
1198         if ( silent )
1199                 memset( src, 0, samples_src * channels_src * sizeof( int16_t ) );
1200
1201         if ( src == dest )
1202         {
1203                 *samples = samples_src;
1204                 *channels = channels_src;
1205                 *buffer = src;
1206                 *frequency = frequency_src;
1207                 return ret;
1208         }
1209
1210         // determine number of samples to process
1211         *samples = samples_src < samples_dest ? samples_src : samples_dest;
1212         *channels = channels_src < channels_dest ? channels_src : channels_dest;
1213         *buffer = dest;
1214         *frequency = frequency_dest;
1215
1216         for ( j = 0; j < *channels; j++ )
1217                 vp[ j ] = ( double )dest[ j ];
1218
1219         double Fc = 0.5;
1220         double B = exp(-2.0 * M_PI * Fc);
1221         double A = 1.0 - B;
1222         double v;
1223
1224         for ( i = 0; i < *samples; i++ )
1225         {
1226                 for ( j = 0; j < *channels; j++ )
1227                 {
1228                         v = ( double )( b_weight * dest[ i * channels_dest + j ] + src[ i * channels_src + j ] );
1229                         v = v < -32767 ? -32767 : v > 32768 ? 32768 : v;
1230                         vp[ j ] = dest[ i * channels_dest + j ] = ( int16_t )( v * A + vp[ j ] * B );
1231                 }
1232         }
1233
1234         return ret;
1235 }
1236
1237 /* Will this break when mlt_position is converted to double? -Zach */
1238 int mlt_sample_calculator( float fps, int frequency, int64_t position )
1239 {
1240         int samples = 0;
1241
1242         if ( ( int )( fps * 100 ) == 2997 )
1243         {
1244                 samples = frequency / 30;
1245
1246                 switch ( frequency )
1247                 {
1248                         case 48000:
1249                                 if ( position % 5 != 0 )
1250                                         samples += 2;
1251                                 break;
1252                         case 44100:
1253                                 if ( position % 300 == 0 )
1254                                         samples = 1471;
1255                                 else if ( position % 30 == 0 )
1256                                         samples = 1470;
1257                                 else if ( position % 2 == 0 )
1258                                         samples = 1472;
1259                                 else
1260                                         samples = 1471;
1261                                 break;
1262                         case 32000:
1263                                 if ( position % 30 == 0 )
1264                                         samples = 1068;
1265                                 else if ( position % 29 == 0 )
1266                                         samples = 1067;
1267                                 else if ( position % 4 == 2 )
1268                                         samples = 1067;
1269                                 else
1270                                         samples = 1068;
1271                                 break;
1272                         default:
1273                                 samples = 0;
1274                 }
1275         }
1276         else if ( fps != 0 )
1277         {
1278                 samples = frequency / fps;
1279         }
1280
1281         return samples;
1282 }
1283
1284 int64_t mlt_sample_calculator_to_now( float fps, int frequency, int64_t frame )
1285 {
1286         int64_t samples = 0;
1287
1288         // TODO: Correct rules for NTSC and drop the * 100 hack
1289         if ( ( int )( fps * 100 ) == 2997 )
1290         {
1291                 samples = ( ( double )( frame * frequency ) / 30 );
1292                 switch( frequency )
1293                 {
1294                         case 48000:
1295                                 samples += 2 * ( frame / 5 );
1296                                 break;
1297                         case 44100:
1298                                 samples += frame + ( frame / 2 ) - ( frame / 30 ) + ( frame / 300 );
1299                                 break;
1300                         case 32000:
1301                                 samples += ( 2 * frame ) - ( frame / 4 ) - ( frame / 29 );
1302                                 break;
1303                 }
1304         }
1305         else if ( fps != 0 )
1306         {
1307                 samples = ( ( frame * frequency ) / ( int )fps );
1308         }
1309
1310         return samples;
1311 }