git.sesse.net Git - mlt/blob - src/modules/avformat/producer_avformat.c

   1 /*
   2  * producer_avformat.c -- avformat producer
   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 // Local header files
  22 #include "producer_avformat.h"
  23
  24 // MLT Header files
  25 #include <framework/mlt_frame.h>
  26
  27 // ffmpeg Header files
  28 #include <ffmpeg/avformat.h>
  29
  30 // System header files
  31 #include <stdlib.h>
  32 #include <string.h>
  33 #include <pthread.h>
  34 #include <math.h>
  35
  36 // Forward references.
  37 static int producer_open( mlt_producer this, char *file );
  38 static int producer_get_frame( mlt_producer this, mlt_frame_ptr frame, int index );
  39
  40 // A static flag used to determine if avformat has been initialised
  41 static int avformat_initialised = 0;
  42 static pthread_mutex_t avformat_mutex;
  43
  44 /** Constructor for libavformat.
  45 */
  46
  47 mlt_producer producer_avformat_init( char *file )
  48 {
  49         mlt_producer this = NULL;
  50
  51         // Check that we have a non-NULL argument
  52         if ( file != NULL )
  53         {
  54                 // Construct the producer
  55                 this = calloc( 1, sizeof( struct mlt_producer_s ) );
  56
  57                 // Initialise it
  58                 if ( mlt_producer_init( this, NULL ) == 0 )
  59                 {
  60                         // Get the properties
  61                         mlt_properties properties = mlt_producer_properties( this );
  62
  63                         // Set the resource property (required for all producers)
  64                         mlt_properties_set( properties, "resource", file );
  65
  66                         // TEST: audio sync tweaking
  67                         mlt_properties_set_double( properties, "discrepancy", 1 );
  68
  69                         // Register our get_frame implementation
  70                         this->get_frame = producer_get_frame;
  71
  72                         // Initialise avformat if necessary
  73                         if ( avformat_initialised == 0 )
  74                         {
  75                                 pthread_mutex_init( &avformat_mutex, NULL );
  76                                 avformat_initialised = 1;
  77                                 av_register_all( );
  78                         }
  79
  80                         // Open the file
  81                         if ( producer_open( this, file ) != 0 )
  82                         {
  83                                 // Clean up
  84                                 mlt_producer_close( this );
  85                                 this = NULL;
  86                         }
  87                 }
  88         }
  89
  90         return this;
  91 }
  92
  93 /** Find the default streams.
  94 */
  95
  96 static void find_default_streams( AVFormatContext *context, int *audio_index, int *video_index )
  97 {
  98         int i;
  99
 100         // Allow for multiple audio and video streams in the file and select first of each (if available)
 101         for( i = 0; i < context->nb_streams; i++ )
 102         {
 103                 // Get the codec context
 104                 AVCodecContext *codec_context = &context->streams[ i ]->codec;
 105
 106                 // Determine the type and obtain the first index of each type
 107                 switch( codec_context->codec_type )
 108                 {
 109                         case CODEC_TYPE_VIDEO:
 110                                 if ( *video_index < 0 )
 111                                         *video_index = i;
 112                                 break;
 113                         case CODEC_TYPE_AUDIO:
 114                                 if ( *audio_index < 0 )
 115                                         *audio_index = i;
 116                                 break;
 117                         default:
 118                                 break;
 119                 }
 120         }
 121 }
 122
 123 /** Producer file destructor.
 124 */
 125
 126 static void producer_file_close( void *context )
 127 {
 128         if ( context != NULL )
 129         {
 130                 // Lock the mutex now
 131                 pthread_mutex_lock( &avformat_mutex );
 132
 133                 // Close the file
 134                 av_close_input_file( context );
 135
 136                 // Unlock the mutex now
 137                 pthread_mutex_unlock( &avformat_mutex );
 138         }
 139 }
 140
 141 /** Producer file destructor.
 142 */
 143
 144 static void producer_codec_close( void *codec )
 145 {
 146         if ( codec != NULL )
 147         {
 148                 // Lock the mutex now
 149                 pthread_mutex_lock( &avformat_mutex );
 150
 151                 // Close the file
 152                 avcodec_close( codec );
 153
 154                 // Unlock the mutex now
 155                 pthread_mutex_unlock( &avformat_mutex );
 156         }
 157 }
 158
 159 /** Open the file.
 160 */
 161
 162 static int producer_open( mlt_producer this, char *file )
 163 {
 164         // Return an error code (0 == no error)
 165         int error = 0;
 166
 167         // Context for avformat
 168         AVFormatContext *context = NULL;
 169
 170         // Get the properties
 171         mlt_properties properties = mlt_producer_properties( this );
 172
 173         // We will treat everything with the producer fps
 174         double fps = mlt_properties_get_double( properties, "fps" );
 175
 176         // Lock the mutex now
 177         pthread_mutex_lock( &avformat_mutex );
 178
 179         // Now attempt to open the file
 180         error = av_open_input_file( &context, file, NULL, 0, NULL );
 181         error = error < 0;
 182
 183         // If successful, then try to get additional info
 184         if ( error == 0 )
 185         {
 186                 // Get the stream info
 187                 error = av_find_stream_info( context ) < 0;
 188
 189                 // Continue if no error
 190                 if ( error == 0 )
 191                 {
 192                         // We will default to the first audio and video streams found
 193                         int audio_index = -1;
 194                         int video_index = -1;
 195
 196                         // Now set properties where we can (use default unknowns if required)
 197                         if ( context->duration != AV_NOPTS_VALUE )
 198                         {
 199                                 // This isn't going to be accurate for all formats
 200                                 mlt_position frames = ( mlt_position )( ( ( double )context->duration / ( double )AV_TIME_BASE ) * fps );
 201                                 mlt_properties_set_position( properties, "out", frames - 2 );
 202                                 mlt_properties_set_position( properties, "length", frames - 1 );
 203                         }
 204
 205                         // Find default audio and video streams
 206                         find_default_streams( context, &audio_index, &video_index );
 207
 208                         // Store selected audio and video indexes on properties
 209                         mlt_properties_set_int( properties, "audio_index", audio_index );
 210                         mlt_properties_set_int( properties, "video_index", video_index );
 211
 212                         // We're going to cheat here - for a/v files, we will have two contexts (reasoning will be clear later)
 213                         if ( audio_index != -1 && video_index != -1 )
 214                         {
 215                                 // We'll use the open one as our video_context
 216                                 mlt_properties_set_data( properties, "video_context", context, 0, producer_file_close, NULL );
 217
 218                                 // And open again for our audio context
 219                                 av_open_input_file( &context, file, NULL, 0, NULL );
 220                                 av_find_stream_info( context );
 221
 222                                 // Audio context
 223                                 mlt_properties_set_data( properties, "audio_context", context, 0, producer_file_close, NULL );
 224                         }
 225                         else if ( video_index != -1 )
 226                         {
 227                                 // We only have a video context
 228                                 mlt_properties_set_data( properties, "video_context", context, 0, producer_file_close, NULL );
 229                         }
 230                         else if ( audio_index != -1 )
 231                         {
 232                                 // We only have an audio context
 233                                 mlt_properties_set_data( properties, "audio_context", context, 0, producer_file_close, NULL );
 234                         }
 235                         else
 236                         {
 237                                 // Something has gone wrong
 238                                 error = -1;
 239                         }
 240                 }
 241         }
 242
 243         // Unlock the mutex now
 244         pthread_mutex_unlock( &avformat_mutex );
 245
 246         return error;
 247 }
 248
 249 /** Convert a frame position to a time code.
 250 */
 251
 252 static double producer_time_of_frame( mlt_producer this, mlt_position position )
 253 {
 254         // Get the properties
 255         mlt_properties properties = mlt_producer_properties( this );
 256
 257         // Obtain the fps
 258         double fps = mlt_properties_get_double( properties, "fps" );
 259
 260         // Do the calc
 261         return ( double )position / fps;
 262 }
 263
 264 /** Get an image from a frame.
 265 */
 266
 267 static int producer_get_image( mlt_frame frame, uint8_t **buffer, mlt_image_format *format, int *width, int *height, int writable )
 268 {
 269         // Get the properties from the frame
 270         mlt_properties frame_properties = mlt_frame_properties( frame );
 271
 272         // Obtain the frame number of this frame
 273         mlt_position position = mlt_properties_get_position( frame_properties, "avformat_position" );
 274
 275         // Get the producer
 276         mlt_producer this = mlt_properties_get_data( frame_properties, "avformat_producer", NULL );
 277
 278         // Get the producer properties
 279         mlt_properties properties = mlt_producer_properties( this );
 280
 281         // Fetch the video_context
 282         AVFormatContext *context = mlt_properties_get_data( properties, "video_context", NULL );
 283
 284         // Get the video_index
 285         int index = mlt_properties_get_int( properties, "video_index" );
 286
 287         // Obtain the expected frame numer
 288         mlt_position expected = mlt_properties_get_position( properties, "video_expected" );
 289
 290         // Calculate the real time code
 291         double real_timecode = producer_time_of_frame( this, position );
 292
 293         // Get the video stream
 294         AVStream *stream = context->streams[ index ];
 295
 296         // Get codec context
 297         AVCodecContext *codec_context = &stream->codec;
 298
 299         // Packet
 300         AVPacket pkt;
 301
 302         // Get the conversion frame
 303         AVPicture *output = mlt_properties_get_data( properties, "video_output_frame", NULL );
 304
 305         // Special case pause handling flag
 306         int paused = 0;
 307
 308         // Special case ffwd handling
 309         int ignore = 0;
 310
 311         // Current time calcs
 312         double current_time = mlt_properties_get_double( properties, "current_time" );
 313
 314         // We may want to use the source fps if available
 315         double source_fps = mlt_properties_get_double( properties, "source_fps" );
 316
 317         // Set the result arguments that we know here (only *buffer is now required)
 318         *format = mlt_image_yuv422;
 319         *width = codec_context->width;
 320         *height = codec_context->height;
 321
 322         // Set this on the frame properties
 323         mlt_properties_set_int( frame_properties, "width", *width );
 324         mlt_properties_set_int( frame_properties, "height", *height );
 325
 326         // Lock the mutex now
 327         pthread_mutex_lock( &avformat_mutex );
 328
 329         // Construct an AVFrame for YUV422 conversion
 330         if ( output == NULL )
 331         {
 332                 int size = avpicture_get_size( PIX_FMT_YUV422, *width, *height );
 333                 size += *width * 2;
 334                 uint8_t *buf = mlt_pool_alloc( size );
 335                 output = mlt_pool_alloc( sizeof( AVPicture ) );
 336                 //memset( output, 0, sizeof( AVPicture ) );
 337                 avpicture_fill( output, buf, PIX_FMT_YUV422, *width, *height );
 338                 mlt_properties_set_data( properties, "video_output_frame", output, 0, ( mlt_destructor )mlt_pool_release, NULL );
 339                 mlt_properties_set_data( properties, "video_output_buffer", buf, 0, ( mlt_destructor )mlt_pool_release, NULL );
 340         }
 341
 342         // Seek if necessary
 343         if ( position != expected )
 344         {
 345                 if ( position + 1 == expected )
 346                 {
 347                         // We're paused - use last image
 348                         paused = 1;
 349                 }
 350                 else if ( position > expected && ( position - expected ) < 250 )
 351                 {
 352                         // Fast forward - seeking is inefficient for small distances - just ignore following frames
 353                         ignore = position - expected;
 354                 }
 355                 else
 356                 {
 357                         // Set to the real timecode
 358                         av_seek_frame( context, -1, real_timecode * 1000000.0 );
 359
 360                         // Remove the cached info relating to the previous position
 361                         mlt_properties_set_double( properties, "current_time", real_timecode );
 362                         mlt_properties_set_data( properties, "current_image", NULL, 0, NULL, NULL );
 363                 }
 364         }
 365
 366         // Duplicate the last image if necessary
 367         if ( mlt_properties_get_data( properties, "current_image", NULL ) != NULL &&
 368                  ( paused || mlt_properties_get_double( properties, "current_time" ) >= real_timecode ) )
 369         {
 370                 // Get current image and size
 371                 int size = 0;
 372                 uint8_t *image = mlt_properties_get_data( properties, "current_image", &size );
 373
 374                 // Duplicate it
 375                 *buffer = mlt_pool_alloc( size );
 376                 memcpy( *buffer, image, size );
 377
 378                 // Set this on the frame properties
 379                 mlt_properties_set_data( frame_properties, "image", *buffer, size, ( mlt_destructor )mlt_pool_release, NULL );
 380         }
 381         else
 382         {
 383                 int ret = 0;
 384                 int got_picture = 0;
 385                 AVFrame frame;
 386
 387                 memset( &pkt, 0, sizeof( pkt ) );
 388                 memset( &frame, 0, sizeof( frame ) );
 389
 390                 while( ret >= 0 && !got_picture )
 391                 {
 392                         // Read a packet
 393                         ret = av_read_frame( context, &pkt );
 394
 395                         // We only deal with video from the selected video_index
 396                         if ( ret >= 0 && pkt.stream_index == index && pkt.size > 0 )
 397                         {
 398                                 // Decode the image
 399                                 ret = avcodec_decode_video( codec_context, &frame, &got_picture, pkt.data, pkt.size );
 400
 401                                 if ( got_picture )
 402                                 {
 403                                         if ( pkt.pts != AV_NOPTS_VALUE && pkt.pts != 0  )
 404                                                 current_time = ( double )pkt.pts / 1000000.0;
 405                                         else
 406                                                 current_time = real_timecode;
 407
 408                                         // Handle ignore
 409                                         if ( current_time < real_timecode )
 410                                         {
 411                                                 ignore = 0;
 412                                                 got_picture = 0;
 413                                         }
 414                                         else if ( current_time >= real_timecode )
 415                                         {
 416                                                 //current_time = real_timecode;
 417                                                 ignore = 0;
 418                                         }
 419                                         else if ( ignore -- )
 420                                         {
 421                                                 got_picture = 0;
 422                                         }
 423                                 }
 424                         }
 425
 426                         // We're finished with this packet regardless
 427                         av_free_packet( &pkt );
 428                 }
 429
 430                 // Now handle the picture if we have one
 431                 if ( got_picture )
 432                 {
 433                         // Get current image and size
 434                         int size = 0;
 435                         uint8_t *image = mlt_properties_get_data( properties, "current_image", &size );
 436
 437                         if ( image == NULL || size != *width * *height * 2 )
 438                         {
 439                                 size = *width * ( *height + 1 ) * 2;
 440                                 image = mlt_pool_alloc( size );
 441                                 mlt_properties_set_data( properties, "current_image", image, size, ( mlt_destructor )mlt_pool_release, NULL );
 442                         }
 443
 444                         *buffer = mlt_pool_alloc( size );
 445
 446                         // EXPERIMENTAL IMAGE NORMALISATIONS
 447                         if ( codec_context->pix_fmt == PIX_FMT_YUV420P )
 448                         {
 449                                 register int i, j;
 450                                 register int half = *width >> 1;
 451                                 register uint8_t *Y = ( ( AVPicture * )&frame )->data[ 0 ];
 452                                 register uint8_t *U = ( ( AVPicture * )&frame )->data[ 1 ];
 453                                 register uint8_t *V = ( ( AVPicture * )&frame )->data[ 2 ];
 454                                 register uint8_t *d = *buffer;
 455                                 register uint8_t *y, *u, *v;
 456
 457                                 i = *height >> 1;
 458                                 while ( i -- )
 459                                 {
 460                                         y = Y;
 461                                         u = U;
 462                                         v = V;
 463                                         j = half;
 464                                         while ( j -- )
 465                                         {
 466                                                 *d ++ = *y ++;
 467                                                 *d ++ = *u ++;
 468                                                 *d ++ = *y ++;
 469                                                 *d ++ = *v ++;
 470                                         }
 471
 472                                         Y += ( ( AVPicture * )&frame )->linesize[ 0 ];
 473                                         y = Y;
 474                                         u = U;
 475                                         v = V;
 476                                         j = half;
 477                                         while ( j -- )
 478                                         {
 479                                                 *d ++ = *y ++;
 480                                                 *d ++ = *u ++;
 481                                                 *d ++ = *y ++;
 482                                                 *d ++ = *v ++;
 483                                         }
 484
 485                                         Y += ( ( AVPicture * )&frame )->linesize[ 0 ];
 486                                         U += ( ( AVPicture * )&frame )->linesize[ 1 ];
 487                                         V += ( ( AVPicture * )&frame )->linesize[ 2 ];
 488                                 }
 489                         }
 490                         else
 491                         {
 492                                 img_convert( output, PIX_FMT_YUV422, (AVPicture *)&frame, codec_context->pix_fmt, *width, *height );
 493                                 memcpy( *buffer, output->data[ 0 ], size );
 494                         }
 495
 496                         memcpy( image, *buffer, size );
 497                         mlt_properties_set_data( frame_properties, "image", *buffer, size, ( mlt_destructor )mlt_pool_release, NULL );
 498
 499                         if ( current_time == 0 && source_fps != 0 )
 500                         {
 501                                 double fps = mlt_properties_get_double( properties, "fps" );
 502                                 current_time = ceil( source_fps * ( double )position / fps ) * ( 1 / source_fps );
 503                                 mlt_properties_set_double( properties, "current_time", current_time );
 504                         }
 505                         else
 506                         {
 507                                 mlt_properties_set_double( properties, "current_time", current_time );
 508                         }
 509                 }
 510         }
 511
 512         // Regardless of speed, we expect to get the next frame (cos we ain't too bright)
 513         mlt_properties_set_position( properties, "video_expected", position + 1 );
 514
 515         // Unlock the mutex now
 516         pthread_mutex_unlock( &avformat_mutex );
 517
 518         return 0;
 519 }
 520
 521 /** Set up video handling.
 522 */
 523
 524 static void producer_set_up_video( mlt_producer this, mlt_frame frame )
 525 {
 526         // Get the properties
 527         mlt_properties properties = mlt_producer_properties( this );
 528
 529         // Fetch the video_context
 530         AVFormatContext *context = mlt_properties_get_data( properties, "video_context", NULL );
 531
 532         // Get the video_index
 533         int index = mlt_properties_get_int( properties, "video_index" );
 534
 535         // Get the frame properties
 536         mlt_properties frame_properties = mlt_frame_properties( frame );
 537
 538         // Lock the mutex now
 539         pthread_mutex_lock( &avformat_mutex );
 540
 541         if ( context != NULL && index != -1 )
 542         {
 543                 // Get the video stream
 544                 AVStream *stream = context->streams[ index ];
 545
 546                 // Get codec context
 547                 AVCodecContext *codec_context = &stream->codec;
 548
 549                 // Get the codec
 550                 AVCodec *codec = mlt_properties_get_data( properties, "video_codec", NULL );
 551
 552                 // Initialise the codec if necessary
 553                 if ( codec == NULL )
 554                 {
 555                         // Find the codec
 556                         codec = avcodec_find_decoder( codec_context->codec_id );
 557
 558                         // If we don't have a codec and we can't initialise it, we can't do much more...
 559                         if ( codec != NULL && avcodec_open( codec_context, codec ) >= 0 )
 560                         {
 561                                 double aspect_ratio = 0;
 562                                 double source_fps = 0;
 563
 564                                 // Set aspect ratio
 565                                 if ( codec_context->sample_aspect_ratio.num == 0 )
 566                                         aspect_ratio = 0;
 567                                 else
 568                                         aspect_ratio = av_q2d( codec_context->sample_aspect_ratio ) * codec_context->width / codec_context->height;
 569
 570                                 // XXX: This assumes square pixels!
 571                         if (aspect_ratio <= 0.0)
 572                                         aspect_ratio = ( double )codec_context->width / ( double )codec_context->height;
 573
 574                                 mlt_properties_set_double( properties, "aspect_ratio", aspect_ratio );
 575                                 fprintf( stderr, "AVFORMAT: sample aspect %f computed display aspect %f\n", av_q2d( codec_context->sample_aspect_ratio ), aspect_ratio );
 576
 577                                 // Determine the fps
 578                                 source_fps = ( double )codec_context->frame_rate / codec_context->frame_rate_base;
 579
 580                                 // We'll use fps if it's available
 581                                 if ( source_fps > 0 && source_fps < 30 )
 582                                         mlt_properties_set_double( properties, "source_fps", source_fps );
 583
 584                                 // Now store the codec with its destructor
 585                                 mlt_properties_set_data( properties, "video_codec", codec_context, 0, producer_codec_close, NULL );
 586                         }
 587                         else
 588                         {
 589                                 // Remember that we can't use this later
 590                                 mlt_properties_set_int( properties, "video_index", -1 );
 591                         }
 592                 }
 593
 594                 // No codec, no show...
 595                 if ( codec != NULL )
 596                 {
 597                         mlt_frame_push_get_image( frame, producer_get_image );
 598                         mlt_properties_set_data( frame_properties, "avformat_producer", this, 0, NULL, NULL );
 599                 }
 600                 else
 601                 {
 602                         mlt_properties_set_int( frame_properties, "test_image", 1 );
 603                 }
 604         }
 605         else
 606         {
 607                 mlt_properties_set_int( frame_properties, "test_image", 1 );
 608         }
 609
 610         // Unlock the mutex now
 611         pthread_mutex_unlock( &avformat_mutex );
 612 }
 613
 614 /** Get the audio from a frame.
 615 */
 616
 617 static int producer_get_audio( mlt_frame frame, int16_t **buffer, mlt_audio_format *format, int *frequency, int *channels, int *samples )
 618 {
 619         // Get the properties from the frame
 620         mlt_properties frame_properties = mlt_frame_properties( frame );
 621
 622         // Obtain the frame number of this frame
 623         mlt_position position = mlt_properties_get_position( frame_properties, "avformat_position" );
 624
 625         // Get the producer
 626         mlt_producer this = mlt_properties_get_data( frame_properties, "avformat_producer", NULL );
 627
 628         // Get the producer properties
 629         mlt_properties properties = mlt_producer_properties( this );
 630
 631         // Fetch the audio_context
 632         AVFormatContext *context = mlt_properties_get_data( properties, "audio_context", NULL );
 633
 634         // Get the audio_index
 635         int index = mlt_properties_get_int( properties, "audio_index" );
 636
 637         // Obtain the expected frame numer
 638         mlt_position expected = mlt_properties_get_position( properties, "audio_expected" );
 639
 640         // Obtain the resample context if it exists (not always needed)
 641         ReSampleContext *resample = mlt_properties_get_data( properties, "audio_resample", NULL );
 642
 643         // Obtain the audio buffer
 644         int16_t *audio_buffer = mlt_properties_get_data( properties, "audio_buffer", NULL );
 645
 646         // Get amount of audio used
 647         int audio_used =  mlt_properties_get_int( properties, "audio_used" );
 648
 649         // Calculate the real time code
 650         double real_timecode = producer_time_of_frame( this, position );
 651
 652         // Get the audio stream
 653         AVStream *stream = context->streams[ index ];
 654
 655         // Get codec context
 656         AVCodecContext *codec_context = &stream->codec;
 657
 658         // Packet
 659         AVPacket pkt;
 660
 661         // Number of frames to ignore (for ffwd)
 662         int ignore = 0;
 663
 664         // Flag for paused (silence)
 665         int paused = 0;
 666         int locked = 0;
 667
 668         // Lock the mutex now
 669         pthread_mutex_lock( &avformat_mutex );
 670
 671         // Check for resample and create if necessary
 672         if ( resample == NULL )
 673         {
 674                 // Create the resampler
 675                 resample = audio_resample_init( *channels, codec_context->channels, *frequency, codec_context->sample_rate );
 676
 677                 // And store it on properties
 678                 mlt_properties_set_data( properties, "audio_resample", resample, 0, ( mlt_destructor )audio_resample_close, NULL );
 679         }
 680
 681         // Check for audio buffer and create if necessary
 682         if ( audio_buffer == NULL )
 683         {
 684                 // Allocate the audio buffer
 685                 audio_buffer = mlt_pool_alloc( AVCODEC_MAX_AUDIO_FRAME_SIZE * sizeof( int16_t ) );
 686
 687                 // And store it on properties for reuse
 688                 mlt_properties_set_data( properties, "audio_buffer", audio_buffer, 0, ( mlt_destructor )mlt_pool_release, NULL );
 689         }
 690
 691         // Seek if necessary
 692         if ( position != expected )
 693         {
 694                 if ( position + 1 == expected )
 695                 {
 696                         // We're paused - silence required
 697                         paused = 1;
 698                 }
 699                 else if ( position > expected && ( position - expected ) < 250 )
 700                 {
 701                         // Fast forward - seeking is inefficient for small distances - just ignore following frames
 702                         ignore = position - expected;
 703                 }
 704                 else
 705                 {
 706                         // Set to the real timecode
 707                         av_seek_frame( context, -1, real_timecode * 1000000.0 );
 708
 709                         // Clear the usage in the audio buffer
 710                         audio_used = 0;
 711
 712                         locked = 1;
 713                 }
 714         }
 715
 716         // Get the audio if required
 717         if ( !paused )
 718         {
 719                 int ret = 0;
 720                 int got_audio = 0;
 721                 int16_t *temp = mlt_pool_alloc( sizeof( int16_t ) * AVCODEC_MAX_AUDIO_FRAME_SIZE );
 722
 723                 memset( &pkt, 0, sizeof( pkt ) );
 724
 725                 while( ret >= 0 && !got_audio )
 726                 {
 727                         // Check if the buffer already contains the samples required
 728                         if ( audio_used >= *samples && ignore == 0 )
 729                         {
 730                                 got_audio = 1;
 731                                 break;
 732                         }
 733
 734                         // Read a packet
 735                         ret = av_read_frame( context, &pkt );
 736
 737                 int len = pkt.size;
 738                 uint8_t *ptr = pkt.data;
 739                         int data_size;
 740
 741                         // We only deal with video from the selected video_index
 742                         while ( ptr != NULL && ret >= 0 && pkt.stream_index == index && len > 0 )
 743                         {
 744                                 // Decode the audio
 745                                 ret = avcodec_decode_audio( codec_context, temp, &data_size, ptr, len );
 746
 747                                 if ( ret < 0 )
 748                                 {
 749                                         ret = 0;
 750                                         break;
 751                                 }
 752
 753                                 len -= ret;
 754                                 ptr += ret;
 755
 756                                 if ( data_size > 0 )
 757                                 {
 758                                         int size_out = audio_resample( resample, &audio_buffer[ audio_used * *channels ], temp, data_size / ( codec_context->channels * sizeof( int16_t ) ) );
 759
 760                                         audio_used += size_out;
 761
 762                                         // Handle ignore
 763                                         while ( ignore && audio_used > *samples )
 764                                         {
 765                                                 ignore --;
 766                                                 audio_used -= *samples;
 767                                                 memmove( audio_buffer, &audio_buffer[ *samples * *channels ], audio_used * sizeof( int16_t ) );
 768                                         }
 769                                 }
 770
 771                                 // If we're behind, ignore this packet
 772                                 float current_pts = (float)pkt.pts / 1000000.0;
 773                                 double discrepancy = mlt_properties_get_double( properties, "discrepancy" );
 774                                 if ( current_pts != 0 && real_timecode != 0 )
 775                                 {
 776                                         if ( discrepancy != 1 )
 777                                                 discrepancy = ( discrepancy + ( real_timecode / current_pts ) ) / 2;
 778                                         else
 779                                                 discrepancy = real_timecode / current_pts;
 780                                         if ( discrepancy > 0.9 && discrepancy < 1.1 )
 781                                                 discrepancy = 1.0;
 782                                         else
 783                                                 discrepancy = floor( discrepancy + 0.5 );
 784
 785                                         if ( discrepancy == 0 )
 786                                                 discrepancy = 1.0;
 787
 788                                         mlt_properties_set_double( properties, "discrepancy", discrepancy );
 789                                 }
 790
 791                                 if ( !ignore && discrepancy * current_pts <= ( real_timecode - 0.02 ) )
 792                                         ignore = 1;
 793                         }
 794
 795                         // We're finished with this packet regardless
 796                         av_free_packet( &pkt );
 797                 }
 798
 799                 *buffer = mlt_pool_alloc( *samples * *channels * sizeof( int16_t ) );
 800                 mlt_properties_set_data( frame_properties, "audio", *buffer, 0, ( mlt_destructor )mlt_pool_release, NULL );
 801
 802                 // Now handle the audio if we have enough
 803                 if ( audio_used >= *samples )
 804                 {
 805                         memcpy( *buffer, audio_buffer, *samples * *channels * sizeof( int16_t ) );
 806                         audio_used -= *samples;
 807                         memmove( audio_buffer, &audio_buffer[ *samples * *channels ], audio_used * *channels * sizeof( int16_t ) );
 808                 }
 809                 else
 810                 {
 811                         memset( *buffer, 0, *samples * *channels * sizeof( int16_t ) );
 812                 }
 813
 814                 // Store the number of audio samples still available
 815                 mlt_properties_set_int( properties, "audio_used", audio_used );
 816
 817                 // Release the temporary audio
 818                 mlt_pool_release( temp );
 819         }
 820         else
 821         {
 822                 // Get silence and don't touch the context
 823                 frame->get_audio = NULL;
 824                 mlt_frame_get_audio( frame, buffer, format, frequency, channels, samples );
 825         }
 826
 827         // Regardless of speed, we expect to get the next frame (cos we ain't too bright)
 828         mlt_properties_set_position( properties, "audio_expected", position + 1 );
 829
 830         // Unlock the mutex now
 831         pthread_mutex_unlock( &avformat_mutex );
 832
 833         return 0;
 834 }
 835
 836 /** Set up audio handling.
 837 */
 838
 839 static void producer_set_up_audio( mlt_producer this, mlt_frame frame )
 840 {
 841         // Get the properties
 842         mlt_properties properties = mlt_producer_properties( this );
 843
 844         // Fetch the audio_context
 845         AVFormatContext *context = mlt_properties_get_data( properties, "audio_context", NULL );
 846
 847         // Get the audio_index
 848         int index = mlt_properties_get_int( properties, "audio_index" );
 849
 850         // Lock the mutex now
 851         pthread_mutex_lock( &avformat_mutex );
 852
 853         // Deal with audio context
 854         if ( context != NULL && index != -1 )
 855         {
 856                 // Get the frame properties
 857                 mlt_properties frame_properties = mlt_frame_properties( frame );
 858
 859                 // Get the audio stream
 860                 AVStream *stream = context->streams[ index ];
 861
 862                 // Get codec context
 863                 AVCodecContext *codec_context = &stream->codec;
 864
 865                 // Get the codec
 866                 AVCodec *codec = mlt_properties_get_data( properties, "audio_codec", NULL );
 867
 868                 // Initialise the codec if necessary
 869                 if ( codec == NULL )
 870                 {
 871                         // Find the codec
 872                         codec = avcodec_find_decoder( codec_context->codec_id );
 873
 874                         // If we don't have a codec and we can't initialise it, we can't do much more...
 875                         if ( codec != NULL && avcodec_open( codec_context, codec ) >= 0 )
 876                         {
 877                                 // Now store the codec with its destructor
 878                                 mlt_properties_set_data( properties, "audio_codec", codec_context, 0, producer_codec_close, NULL );
 879
 880                         }
 881                         else
 882                         {
 883                                 // Remember that we can't use this later
 884                                 mlt_properties_set_int( properties, "audio_index", -1 );
 885                         }
 886                 }
 887
 888                 // No codec, no show...
 889                 if ( codec != NULL )
 890                 {
 891                         frame->get_audio = producer_get_audio;
 892                         mlt_properties_set_data( frame_properties, "avformat_producer", this, 0, NULL, NULL );
 893                 }
 894         }
 895
 896         // Unlock the mutex now
 897         pthread_mutex_unlock( &avformat_mutex );
 898 }
 899
 900 /** Our get frame implementation.
 901 */
 902
 903 static int producer_get_frame( mlt_producer this, mlt_frame_ptr frame, int index )
 904 {
 905         // Create an empty frame
 906         *frame = mlt_frame_init( );
 907
 908         // Update timecode on the frame we're creating
 909         mlt_frame_set_position( *frame, mlt_producer_position( this ) );
 910
 911         // Set the position of this producer
 912         mlt_properties_set_position( mlt_frame_properties( *frame ), "avformat_position", mlt_producer_get_in( this ) + mlt_producer_position( this ) );
 913
 914         // Set up the video
 915         producer_set_up_video( this, *frame );
 916
 917         // Set up the audio
 918         producer_set_up_audio( this, *frame );
 919
 920         // Set the aspect_ratio
 921         mlt_properties_set_double( mlt_frame_properties( *frame ), "aspect_ratio", mlt_properties_get_double( mlt_producer_properties( this ), "aspect_ratio" ) );
 922
 923         // Calculate the next timecode
 924         mlt_producer_prepare_next( this );
 925
 926         return 0;
 927 }