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 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 != NULL ? &this->parent : NULL;
  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 unsigned char *mlt_frame_get_waveform( mlt_frame this, double fps, int w, int h )
 343 {
 344         /* Currently, w is not honored - the user must scale to desired height.
 345            Get the integer property waveform_width after calling to see the
 346            produced width (currently equal to # samples). */
 347         int16_t *pcm = NULL;
 348         mlt_properties properties = mlt_frame_properties( this );
 349         mlt_audio_format format = mlt_audio_pcm;
 350         int frequency = 32000; /* lower frequency available? */
 351         int channels = 2;
 352         int samples = mlt_sample_calculator( fps, frequency, mlt_frame_get_position( this ) );
 353
 354         /* get the pcm data */
 355         mlt_frame_get_audio( this, &pcm, &format, &frequency, &channels, &samples );
 356         mlt_properties_set_int( properties, "waveform_width", samples );
 357
 358         /* make an 8-bit buffer large enough to hold rendering */
 359         int size = samples * h;
 360         unsigned char *bitmap = ( unsigned char* )mlt_pool_alloc( size );
 361         if ( bitmap != NULL )
 362                 memset( bitmap, 0, size );
 363         mlt_properties_set_data( properties, "waveform", bitmap, size, ( mlt_destructor )mlt_pool_release, NULL );
 364
 365         /* render - pcm data has channels interleaved */
 366         int vertical_resolution = h / channels;
 367         int i, j, k;
 368
 369         for ( i = 0; i < samples; i++ )
 370         {
 371                 for ( j = 0; j < channels; j++ )
 372                 {
 373                         /* the height of a "bar" is the ratio of the sample multiplied by the vertical resolution */
 374                         int pcm_scaled = ( int )( ( double )( *pcm ) / 32768 * vertical_resolution / 2 );
 375                         int height = pcm_scaled < 0 ? -pcm_scaled : pcm_scaled;
 376                         int offset = j * samples * vertical_resolution;
 377                         int displacement = pcm_scaled < 0 ? ( vertical_resolution / 2 ) : ( vertical_resolution / 2 - pcm_scaled );
 378                         unsigned char *p = &bitmap[ offset + i + displacement * samples ];
 379
 380                         for ( k = 0; k < height; k++ )
 381                                 p[ samples * k ] = 0xFF;
 382
 383                         pcm++;
 384                 }
 385         }
 386
 387         return bitmap;
 388 }
 389
 390
 391 void mlt_frame_close( mlt_frame this )
 392 {
 393         if ( this != NULL && mlt_properties_dec_ref( mlt_frame_properties( this ) ) <= 0 )
 394         {
 395                 mlt_deque_close( this->stack_image );
 396                 mlt_deque_close( this->stack_audio );
 397                 mlt_properties_close( &this->parent );
 398                 free( this );
 399         }
 400 }
 401
 402 /***** convenience functions *****/
 403
 404 int mlt_convert_rgb24a_to_yuv422( uint8_t *rgba, int width, int height, int stride, uint8_t *yuv, uint8_t *alpha )
 405 {
 406         int ret = 0;
 407         register int y0, y1, u0, u1, v0, v1;
 408         register int r, g, b;
 409         register uint8_t *d = yuv;
 410         register int i, j;
 411
 412         for ( i = 0; i < height; i++ )
 413         {
 414                 register uint8_t *s = rgba + ( stride * i );
 415                 for ( j = 0; j < ( width / 2 ); j++ )
 416                 {
 417                         r = *s++;
 418                         g = *s++;
 419                         b = *s++;
 420                         *alpha++ = *s++;
 421                         RGB2YUV (r, g, b, y0, u0 , v0);
 422                         r = *s++;
 423                         g = *s++;
 424                         b = *s++;
 425                         *alpha++ = *s++;
 426                         RGB2YUV (r, g, b, y1, u1 , v1);
 427                         *d++ = y0;
 428                         *d++ = (u0+u1) >> 1;
 429                         *d++ = y1;
 430                         *d++ = (v0+v1) >> 1;
 431                 }
 432                 if ( width % 2 )
 433                 {
 434                         r = *s++;
 435                         g = *s++;
 436                         b = *s++;
 437                         *alpha++ = *s++;
 438                         RGB2YUV (r, g, b, y0, u0 , v0);
 439                         *d++ = y0;
 440                         *d++ = u0;
 441                 }
 442         }
 443         return ret;
 444 }
 445
 446 int mlt_convert_rgb24_to_yuv422( uint8_t *rgb, int width, int height, int stride, uint8_t *yuv )
 447 {
 448         int ret = 0;
 449         register int y0, y1, u0, u1, v0, v1;
 450         register int r, g, b;
 451         register uint8_t *d = yuv;
 452         register int i, j;
 453
 454         for ( i = 0; i < height; i++ )
 455         {
 456                 register uint8_t *s = rgb + ( stride * i );
 457                 for ( j = 0; j < ( width / 2 ); j++ )
 458                 {
 459                         r = *s++;
 460                         g = *s++;
 461                         b = *s++;
 462                         RGB2YUV (r, g, b, y0, u0 , v0);
 463                         r = *s++;
 464                         g = *s++;
 465                         b = *s++;
 466                         RGB2YUV (r, g, b, y1, u1 , v1);
 467                         *d++ = y0;
 468                         *d++ = (u0+u1) >> 1;
 469                         *d++ = y1;
 470                         *d++ = (v0+v1) >> 1;
 471                 }
 472                 if ( width % 2 )
 473                 {
 474                         r = *s++;
 475                         g = *s++;
 476                         b = *s++;
 477                         RGB2YUV (r, g, b, y0, u0 , v0);
 478                         *d++ = y0;
 479                         *d++ = u0;
 480                 }
 481         }
 482         return ret;
 483 }
 484
 485 int mlt_convert_yuv420p_to_yuv422( uint8_t *yuv420p, int width, int height, int stride, uint8_t *yuv )
 486 {
 487         int ret = 0;
 488         register int i, j;
 489
 490         int half = width >> 1;
 491
 492         uint8_t *Y = yuv420p;
 493         uint8_t *U = Y + width * height;
 494         uint8_t *V = U + width * height / 4;
 495
 496         register uint8_t *d = yuv;
 497
 498         for ( i = 0; i < height; i++ )
 499         {
 500                 register uint8_t *u = U + ( i / 2 ) * ( half );
 501                 register uint8_t *v = V + ( i / 2 ) * ( half );
 502
 503                 for ( j = 0; j < half; j++ )
 504                 {
 505                         *d ++ = *Y ++;
 506                         *d ++ = *u ++;
 507                         *d ++ = *Y ++;
 508                         *d ++ = *v ++;
 509                 }
 510         }
 511         return ret;
 512 }
 513
 514 void mlt_resize_yuv422( uint8_t *output, int owidth, int oheight, uint8_t *input, int iwidth, int iheight )
 515 {
 516         // Calculate strides
 517         int istride = iwidth * 2;
 518         int ostride = owidth * 2;
 519
 520         iwidth = iwidth - ( iwidth % 4 );
 521         owidth = owidth - ( owidth % 4 );
 522         iheight = iheight - ( iheight % 2 );
 523         oheight = oheight - ( oheight % 2 );
 524
 525         // Optimisation point
 526         if ( iwidth == owidth && iheight == oheight )
 527                 memcpy( output, input, iheight * istride );
 528
 529         // Coordinates (0,0 is middle of output)
 530         int y;
 531
 532         // Calculate ranges
 533         int out_x_range = owidth / 2;
 534         int out_y_range = oheight / 2;
 535         int in_x_range = iwidth / 2 < out_x_range ? iwidth / 2 : out_x_range;
 536         int in_y_range = iheight / 2 < out_y_range ? iheight / 2 : out_y_range;
 537
 538         // Output pointers
 539         uint8_t *out_line = output;
 540         uint8_t *out_ptr = out_line;
 541
 542         // Calculate a middle and possibly invalid pointer in the input
 543         uint8_t *in_middle = input + istride * ( iheight / 2 ) + ( iwidth / 2 ) * 2;
 544         int in_line = - in_y_range * istride - in_x_range * 2;
 545
 546         int elements;
 547
 548         // Fill whole section with black
 549         y = out_y_range - ( iheight / 2 );
 550         int blank_elements = ostride * y / 2;
 551         elements = blank_elements;
 552         while ( elements -- )
 553         {
 554                 *out_line ++ = 16;
 555                 *out_line ++ = 128;
 556         }
 557
 558         int active_width = 2 * iwidth;
 559         int inactive_width = out_x_range - in_x_range;
 560         uint8_t *p = NULL;
 561         uint8_t *end = NULL;
 562
 563         // Loop for the entirety of our output height.
 564         while ( iheight -- )
 565         {
 566         // Start at the beginning of the line
 567         out_ptr = out_line;
 568
 569                 // Fill the outer part with black
 570                 elements = inactive_width;
 571                 while ( elements -- )
 572                 {
 573                         *out_ptr ++ = 16;
 574                         *out_ptr ++ = 128;
 575                 }
 576
 577                 // We're in the input range for this row.
 578                 p = in_middle + in_line;
 579                 end = out_ptr + active_width;
 580                 while ( out_ptr != end )
 581                 {
 582                         *out_ptr ++ = *p ++;
 583                         *out_ptr ++ = *p ++;
 584                 }
 585
 586                 // Fill the outer part with black
 587                 elements = inactive_width;
 588                 while ( elements -- )
 589                 {
 590                         *out_ptr ++ = 16;
 591                         *out_ptr ++ = 128;
 592                 }
 593
 594                 // Move to next input line
 595                 in_line += istride;
 596
 597         // Move to next output line
 598         out_line += ostride;
 599         }
 600
 601         // Fill whole section with black
 602         elements = blank_elements;
 603         while ( elements -- )
 604         {
 605                 *out_line ++ = 16;
 606                 *out_line ++ = 128;
 607         }
 608 }
 609
 610 /** A resizing function for yuv422 frames - this does not rescale, but simply
 611         resizes. It assumes yuv422 images available on the frame so use with care.
 612 */
 613
 614 uint8_t *mlt_frame_resize_yuv422( mlt_frame this, int owidth, int oheight )
 615 {
 616         // Get properties
 617         mlt_properties properties = mlt_frame_properties( this );
 618
 619         // Get the input image, width and height
 620         uint8_t *input = mlt_properties_get_data( properties, "image", NULL );
 621         int iwidth = mlt_properties_get_int( properties, "width" );
 622         int iheight = mlt_properties_get_int( properties, "height" );
 623
 624         // If width and height are correct, don't do anything
 625         if ( iwidth != owidth || iheight != oheight )
 626         {
 627                 // Create the output image
 628                 uint8_t *output = mlt_pool_alloc( owidth * ( oheight + 1 ) * 2 );
 629
 630                 // Call the generic resize
 631                 mlt_resize_yuv422( output, owidth, oheight, input, iwidth, iheight );
 632
 633                 // Now update the frame
 634                 mlt_properties_set_data( properties, "image", output, owidth * ( oheight + 1 ) * 2, ( mlt_destructor )mlt_pool_release, NULL );
 635                 mlt_properties_set_int( properties, "width", owidth );
 636                 mlt_properties_set_int( properties, "height", oheight );
 637
 638                 // Return the output
 639                 return output;
 640         }
 641         // No change, return input
 642         return input;
 643 }
 644
 645 /** A rescaling function for yuv422 frames - low quality, and provided for testing
 646         only. It assumes yuv422 images available on the frame so use with care.
 647 */
 648
 649 uint8_t *mlt_frame_rescale_yuv422( mlt_frame this, int owidth, int oheight )
 650 {
 651         // Get properties
 652         mlt_properties properties = mlt_frame_properties( this );
 653
 654         // Get the input image, width and height
 655         uint8_t *input = mlt_properties_get_data( properties, "image", NULL );
 656         int iwidth = mlt_properties_get_int( properties, "width" );
 657         int iheight = mlt_properties_get_int( properties, "height" );
 658
 659         // If width and height are correct, don't do anything
 660         if ( iwidth != owidth || iheight != oheight )
 661         {
 662                 // Create the output image
 663                 uint8_t *output = mlt_pool_alloc( owidth * ( oheight + 1 ) * 2 );
 664
 665                 // Calculate strides
 666                 int istride = iwidth * 2;
 667                 int ostride = owidth * 2;
 668
 669                 iwidth = iwidth - ( iwidth % 4 );
 670
 671                 // Derived coordinates
 672                 int dy, dx;
 673
 674         // Calculate ranges
 675         int out_x_range = owidth / 2;
 676         int out_y_range = oheight / 2;
 677         int in_x_range = iwidth / 2;
 678         int in_y_range = iheight / 2;
 679
 680         // Output pointers
 681         register uint8_t *out_line = output;
 682         register uint8_t *out_ptr;
 683
 684         // Calculate a middle pointer
 685         uint8_t *in_middle = input + istride * in_y_range + in_x_range * 2;
 686         uint8_t *in_line;
 687
 688                 // Generate the affine transform scaling values
 689                 register int scale_width = ( iwidth << 16 ) / owidth;
 690                 register int scale_height = ( iheight << 16 ) / oheight;
 691                 register int base = 0;
 692
 693                 int outer = out_x_range * scale_width;
 694                 int bottom = out_y_range * scale_height;
 695
 696         // Loop for the entirety of our output height.
 697         for ( dy = - bottom; dy < bottom; dy += scale_height )
 698         {
 699                 // Start at the beginning of the line
 700                 out_ptr = out_line;
 701
 702                 // Pointer to the middle of the input line
 703                 in_line = in_middle + ( dy >> 16 ) * istride;
 704
 705                 // Loop for the entirety of our output row.
 706                 for ( dx = - outer; dx < outer; dx += scale_width )
 707                 {
 708                                 base = dx >> 15;
 709                                 base &= 0xfffffffe;
 710                                 *out_ptr ++ = *( in_line + base );
 711                                 base &= 0xfffffffc;
 712                                 *out_ptr ++ = *( in_line + base + 1 );
 713                                 dx += scale_width;
 714                                 base = dx >> 15;
 715                                 base &= 0xfffffffe;
 716                                 *out_ptr ++ = *( in_line + base );
 717                                 base &= 0xfffffffc;
 718                                 *out_ptr ++ = *( in_line + base + 3 );
 719                 }
 720
 721                 // Move to next output line
 722                 out_line += ostride;
 723         }
 724
 725                 // Now update the frame
 726                 mlt_properties_set_data( properties, "image", output, owidth * ( oheight + 1 ) * 2, ( mlt_destructor )mlt_pool_release, NULL );
 727                 mlt_properties_set_int( properties, "width", owidth );
 728                 mlt_properties_set_int( properties, "height", oheight );
 729
 730                 // Return the output
 731                 return output;
 732         }
 733
 734         // No change, return input
 735         return input;
 736 }
 737
 738 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 )
 739 {
 740         int ret = 0;
 741         int16_t *src, *dest;
 742         int frequency_src = *frequency, frequency_dest = *frequency;
 743         int channels_src = *channels, channels_dest = *channels;
 744         int samples_src = *samples, samples_dest = *samples;
 745         int i, j;
 746         double d = 0, s = 0;
 747
 748         mlt_frame_get_audio( this, &dest, format, &frequency_dest, &channels_dest, &samples_dest );
 749         //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" ) );
 750         mlt_frame_get_audio( that, &src, format, &frequency_src, &channels_src, &samples_src );
 751         //fprintf( stderr, "mix: frame src  samples %d channels %d\n", samples_src, channels_src );
 752
 753         if ( channels_src > 6 )
 754                 channels_src = 0;
 755         if ( channels_dest > 6 )
 756                 channels_dest = 0;
 757         if ( samples_src > 4000 )
 758                 samples_src = 0;
 759         if ( samples_dest > 4000 )
 760                 samples_dest = 0;
 761
 762         // determine number of samples to process
 763         *samples = samples_src < samples_dest ? samples_src : samples_dest;
 764         *channels = channels_src < channels_dest ? channels_src : channels_dest;
 765         *buffer = dest;
 766         *frequency = frequency_dest;
 767
 768         // Compute a smooth ramp over start to end
 769         float weight = weight_start;
 770         float weight_step = ( weight_end - weight_start ) / *samples;
 771
 772         // Mixdown
 773         for ( i = 0; i < *samples; i++ )
 774         {
 775                 for ( j = 0; j < *channels; j++ )
 776                 {
 777                         if ( j < channels_dest )
 778                                 d = (double) dest[ i * channels_dest + j ];
 779                         if ( j < channels_src )
 780                                 s = (double) src[ i * channels_src + j ];
 781                         dest[ i * channels_dest + j ] = s * weight + d * ( 1.0 - weight );
 782                 }
 783                 weight += weight_step;
 784         }
 785
 786         return ret;
 787 }
 788
 789 int mlt_sample_calculator( float fps, int frequency, int64_t position )
 790 {
 791         int samples = 0;
 792
 793         if ( ( int )( fps * 100 ) == 2997 )
 794         {
 795                 samples = frequency / 30;
 796
 797                 switch ( frequency )
 798                 {
 799                         case 48000:
 800                                 if ( position % 5 != 0 )
 801                                         samples += 2;
 802                                 break;
 803                         case 44100:
 804                                 if ( position % 300 == 0 )
 805                                         samples = 1471;
 806                                 else if ( position % 30 == 0 )
 807                                         samples = 1470;
 808                                 else if ( position % 2 == 0 )
 809                                         samples = 1472;
 810                                 else
 811                                         samples = 1471;
 812                                 break;
 813                         case 32000:
 814                                 if ( position % 30 == 0 )
 815                                         samples = 1068;
 816                                 else if ( position % 29 == 0 )
 817                                         samples = 1067;
 818                                 else if ( position % 4 == 2 )
 819                                         samples = 1067;
 820                                 else
 821                                         samples = 1068;
 822                                 break;
 823                         default:
 824                                 samples = 0;
 825                 }
 826         }
 827         else if ( fps != 0 )
 828         {
 829                 samples = frequency / fps;
 830         }
 831
 832         return samples;
 833 }