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 <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 void avformat_lock( );
  37 void avformat_unlock( );
  38
  39 // Forward references.
  40 static int producer_open( mlt_producer this, char *file );
  41 static int producer_get_frame( mlt_producer this, mlt_frame_ptr frame, int index );
  42
  43 /** Constructor for libavformat.
  44 */
  45
  46 mlt_producer producer_avformat_init( char *file )
  47 {
  48         mlt_producer this = NULL;
  49
  50         // Check that we have a non-NULL argument
  51         if ( file != NULL )
  52         {
  53                 // Construct the producer
  54                 this = calloc( 1, sizeof( struct mlt_producer_s ) );
  55
  56                 // Initialise it
  57                 if ( mlt_producer_init( this, NULL ) == 0 )
  58                 {
  59                         // Get the properties
  60                         mlt_properties properties = mlt_producer_properties( this );
  61
  62                         // Set the resource property (required for all producers)
  63                         mlt_properties_set( properties, "resource", file );
  64
  65                         // TEST: audio sync tweaking
  66                         mlt_properties_set_double( properties, "discrepancy", 1 );
  67
  68                         // Register our get_frame implementation
  69                         this->get_frame = producer_get_frame;
  70
  71                         // Open the file
  72                         if ( producer_open( this, file ) != 0 )
  73                         {
  74                                 // Clean up
  75                                 mlt_producer_close( this );
  76                                 this = NULL;
  77                         }
  78                 }
  79         }
  80
  81         return this;
  82 }
  83
  84 /** Find the default streams.
  85 */
  86
  87 static void find_default_streams( AVFormatContext *context, int *audio_index, int *video_index )
  88 {
  89         int i;
  90
  91         // Allow for multiple audio and video streams in the file and select first of each (if available)
  92         for( i = 0; i < context->nb_streams; i++ )
  93         {
  94                 // Get the codec context
  95                 AVCodecContext *codec_context = &context->streams[ i ]->codec;
  96
  97                 // Determine the type and obtain the first index of each type
  98                 switch( codec_context->codec_type )
  99                 {
 100                         case CODEC_TYPE_VIDEO:
 101                                 if ( *video_index < 0 )
 102                                         *video_index = i;
 103                                 break;
 104                         case CODEC_TYPE_AUDIO:
 105                                 if ( *audio_index < 0 )
 106                                         *audio_index = i;
 107                                 break;
 108                         default:
 109                                 break;
 110                 }
 111         }
 112 }
 113
 114 /** Producer file destructor.
 115 */
 116
 117 static void producer_file_close( void *context )
 118 {
 119         if ( context != NULL )
 120         {
 121                 // Lock the mutex now
 122                 avformat_lock( );
 123
 124                 // Close the file
 125                 av_close_input_file( context );
 126
 127                 // Unlock the mutex now
 128                 avformat_unlock( );
 129         }
 130 }
 131
 132 /** Producer file destructor.
 133 */
 134
 135 static void producer_codec_close( void *codec )
 136 {
 137         if ( codec != NULL )
 138         {
 139                 // Lock the mutex now
 140                 avformat_lock( );
 141
 142                 // Close the file
 143                 avcodec_close( codec );
 144
 145                 // Unlock the mutex now
 146                 avformat_unlock( );
 147         }
 148 }
 149
 150 /** Open the file.
 151 */
 152
 153 static int producer_open( mlt_producer this, char *file )
 154 {
 155         // Return an error code (0 == no error)
 156         int error = 0;
 157
 158         // Context for avformat
 159         AVFormatContext *context = NULL;
 160
 161         // Get the properties
 162         mlt_properties properties = mlt_producer_properties( this );
 163
 164         // We will treat everything with the producer fps
 165         double fps = mlt_properties_get_double( properties, "fps" );
 166
 167         // Lock the mutex now
 168         avformat_lock( );
 169
 170         // If "MRL", then create AVInputFormat
 171         AVInputFormat *format = NULL;
 172         AVFormatParameters *params = NULL;
 173         char *standard = NULL;
 174         char *mrl = strchr( file, ':' );
 175
 176         // Only if there is not a protocol specification that avformat can handle
 177         if ( mrl && !url_exist( file ) )
 178         {
 179                 // 'file' becomes format abbreviation
 180                 mrl[0] = 0;
 181
 182                 // Lookup the format
 183                 format = av_find_input_format( file );
 184
 185                 // Eat the format designator
 186                 file = ++mrl;
 187
 188                 if ( format )
 189                 {
 190                         // Allocate params
 191                         params = calloc( sizeof( AVFormatParameters ), 1 );
 192
 193                         // These are required by video4linux (defaults)
 194                         params->width = 640;
 195                         params->height = 480;
 196                         params->frame_rate = 25;
 197                         params->frame_rate_base = 1;
 198                         params->device = file;
 199                         params->channels = 2;
 200                         params->sample_rate = 48000;
 201                 }
 202
 203                 // Parse out params
 204                 mrl = strchr( file, '?' );
 205                 while ( mrl )
 206                 {
 207                         mrl[0] = 0;
 208                         char *name = strdup( ++mrl );
 209                         char *value = strchr( name, ':' );
 210                         if ( value )
 211                         {
 212                                 value[0] = 0;
 213                                 value++;
 214                                 char *t = strchr( value, '&' );
 215                                 if ( t )
 216                                         t[0] = 0;
 217                                 if ( !strcmp( name, "frame_rate" ) )
 218                                         params->frame_rate = atoi( value );
 219                                 else if ( !strcmp( name, "frame_rate_base" ) )
 220                                         params->frame_rate_base = atoi( value );
 221                                 else if ( !strcmp( name, "sample_rate" ) )
 222                                         params->sample_rate = atoi( value );
 223                                 else if ( !strcmp( name, "channels" ) )
 224                                         params->channels = atoi( value );
 225                                 else if ( !strcmp( name, "width" ) )
 226                                         params->width = atoi( value );
 227                                 else if ( !strcmp( name, "height" ) )
 228                                         params->height = atoi( value );
 229                                 else if ( !strcmp( name, "standard" ) )
 230                                 {
 231                                         standard = strdup( value );
 232                                         params->standard = standard;
 233                                 }
 234                         }
 235                         free( name );
 236                         mrl = strchr( mrl, '&' );
 237                 }
 238         }
 239
 240         // Now attempt to open the file
 241         error = av_open_input_file( &context, file, format, 0, params );
 242         error = error < 0;
 243
 244         // Cleanup AVFormatParameters
 245         free( standard );
 246         free( params );
 247
 248         // If successful, then try to get additional info
 249         if ( error == 0 )
 250         {
 251                 // Get the stream info
 252                 error = av_find_stream_info( context ) < 0;
 253
 254                 // Continue if no error
 255                 if ( error == 0 )
 256                 {
 257                         // We will default to the first audio and video streams found
 258                         int audio_index = -1;
 259                         int video_index = -1;
 260
 261                         // Now set properties where we can (use default unknowns if required)
 262                         if ( context->duration != AV_NOPTS_VALUE )
 263                         {
 264                                 // This isn't going to be accurate for all formats
 265                                 mlt_position frames = ( mlt_position )( ( ( double )context->duration / ( double )AV_TIME_BASE ) * fps );
 266                                 mlt_properties_set_position( properties, "out", frames - 2 );
 267                                 mlt_properties_set_position( properties, "length", frames - 1 );
 268                         }
 269
 270                         // Find default audio and video streams
 271                         find_default_streams( context, &audio_index, &video_index );
 272
 273                         // Check if we're seekable (something funny about mpeg here :-/)
 274                         if ( strstr( file, ".mpg" ) == NULL && strstr( file, ".mpeg" ) == NULL )
 275                                 mlt_properties_set_int( properties, "seekable", av_seek_frame( context, -1, context->start_time ) >= 0 );
 276                         else
 277                                 mlt_properties_set_int( properties, "seekable", 1 );
 278
 279                         // Store selected audio and video indexes on properties
 280                         mlt_properties_set_int( properties, "audio_index", audio_index );
 281                         mlt_properties_set_int( properties, "video_index", video_index );
 282
 283                         // We're going to cheat here - for a/v files, we will have two contexts (reasoning will be clear later)
 284                         if ( audio_index != -1 && video_index != -1 )
 285                         {
 286                                 // We'll use the open one as our video_context
 287                                 mlt_properties_set_data( properties, "video_context", context, 0, producer_file_close, NULL );
 288
 289                                 // And open again for our audio context
 290                                 av_open_input_file( &context, file, NULL, 0, NULL );
 291                                 av_find_stream_info( context );
 292
 293                                 // Audio context
 294                                 mlt_properties_set_data( properties, "audio_context", context, 0, producer_file_close, NULL );
 295                         }
 296                         else if ( video_index != -1 )
 297                         {
 298                                 // We only have a video context
 299                                 mlt_properties_set_data( properties, "video_context", context, 0, producer_file_close, NULL );
 300                         }
 301                         else if ( audio_index != -1 )
 302                         {
 303                                 // We only have an audio context
 304                                 mlt_properties_set_data( properties, "audio_context", context, 0, producer_file_close, NULL );
 305                         }
 306                         else
 307                         {
 308                                 // Something has gone wrong
 309                                 error = -1;
 310                         }
 311                 }
 312         }
 313
 314         // Unlock the mutex now
 315         avformat_unlock( );
 316
 317         return error;
 318 }
 319
 320 /** Convert a frame position to a time code.
 321 */
 322
 323 static double producer_time_of_frame( mlt_producer this, mlt_position position )
 324 {
 325         // Get the properties
 326         mlt_properties properties = mlt_producer_properties( this );
 327
 328         // Obtain the fps
 329         double fps = mlt_properties_get_double( properties, "fps" );
 330
 331         // Do the calc
 332         return ( double )position / fps;
 333 }
 334
 335 /** Get an image from a frame.
 336 */
 337
 338 static int producer_get_image( mlt_frame frame, uint8_t **buffer, mlt_image_format *format, int *width, int *height, int writable )
 339 {
 340         // Get the properties from the frame
 341         mlt_properties frame_properties = mlt_frame_properties( frame );
 342
 343         // Obtain the frame number of this frame
 344         mlt_position position = mlt_properties_get_position( frame_properties, "avformat_position" );
 345
 346         // Get the producer
 347         mlt_producer this = mlt_properties_get_data( frame_properties, "avformat_producer", NULL );
 348
 349         // Get the producer properties
 350         mlt_properties properties = mlt_producer_properties( this );
 351
 352         // Fetch the video_context
 353         AVFormatContext *context = mlt_properties_get_data( properties, "video_context", NULL );
 354
 355         // Get the video_index
 356         int index = mlt_properties_get_int( properties, "video_index" );
 357
 358         // Obtain the expected frame numer
 359         mlt_position expected = mlt_properties_get_position( properties, "video_expected" );
 360
 361         // Calculate the real time code
 362         double real_timecode = producer_time_of_frame( this, position );
 363
 364         // Get the video stream
 365         AVStream *stream = context->streams[ index ];
 366
 367         // Get codec context
 368         AVCodecContext *codec_context = &stream->codec;
 369
 370         // Packet
 371         AVPacket pkt;
 372
 373         // Get the conversion frame
 374         AVPicture *output = mlt_properties_get_data( properties, "video_output_frame", NULL );
 375
 376         // Special case pause handling flag
 377         int paused = 0;
 378
 379         // Special case ffwd handling
 380         int ignore = 0;
 381
 382         // Current time calcs
 383         double current_time = mlt_properties_get_double( properties, "current_time" );
 384
 385         // We may want to use the source fps if available
 386         double source_fps = mlt_properties_get_double( properties, "source_fps" );
 387
 388         // Set the result arguments that we know here (only *buffer is now required)
 389         *format = mlt_image_yuv422;
 390         *width = codec_context->width;
 391         *height = codec_context->height;
 392
 393         // Set this on the frame properties
 394         mlt_properties_set_int( frame_properties, "width", *width );
 395         mlt_properties_set_int( frame_properties, "height", *height );
 396
 397         // Lock the mutex now
 398         avformat_lock( );
 399
 400         // Construct an AVFrame for YUV422 conversion
 401         if ( output == NULL )
 402         {
 403                 int size = avpicture_get_size( PIX_FMT_YUV422, *width, *height + 1 );
 404                 uint8_t *buf = mlt_pool_alloc( size );
 405                 output = mlt_pool_alloc( sizeof( AVPicture ) );
 406                 avpicture_fill( output, buf, PIX_FMT_YUV422, *width, *height );
 407                 mlt_properties_set_data( properties, "video_output_frame", output, 0, ( mlt_destructor )mlt_pool_release, NULL );
 408                 mlt_properties_set_data( properties, "video_output_buffer", buf, 0, ( mlt_destructor )mlt_pool_release, NULL );
 409         }
 410
 411         // Seek if necessary
 412         if ( position != expected )
 413         {
 414                 if ( position + 1 == expected )
 415                 {
 416                         // We're paused - use last image
 417                         paused = 1;
 418                 }
 419                 else if ( position > expected && ( position - expected ) < 250 )
 420                 {
 421                         // Fast forward - seeking is inefficient for small distances - just ignore following frames
 422                         ignore = position - expected;
 423                 }
 424                 else
 425                 {
 426                         // Set to the real timecode
 427                         av_seek_frame( context, -1, context->start_time + real_timecode * 1000000.0 );
 428
 429                         // Remove the cached info relating to the previous position
 430                         mlt_properties_set_double( properties, "current_time", real_timecode );
 431                         mlt_properties_set_data( properties, "current_image", NULL, 0, NULL, NULL );
 432                 }
 433         }
 434
 435         // Duplicate the last image if necessary
 436         if ( mlt_properties_get_data( properties, "current_image", NULL ) != NULL &&
 437                  ( paused || mlt_properties_get_double( properties, "current_time" ) >= real_timecode ) )
 438         {
 439                 // Get current image and size
 440                 int size = 0;
 441                 uint8_t *image = mlt_properties_get_data( properties, "current_image", &size );
 442
 443                 // Duplicate it
 444                 *buffer = mlt_pool_alloc( size );
 445                 memcpy( *buffer, image, size );
 446
 447                 // Set this on the frame properties
 448                 mlt_properties_set_data( frame_properties, "image", *buffer, size, ( mlt_destructor )mlt_pool_release, NULL );
 449         }
 450         else
 451         {
 452                 int ret = 0;
 453                 int got_picture = 0;
 454                 AVFrame frame;
 455
 456                 memset( &pkt, 0, sizeof( pkt ) );
 457                 memset( &frame, 0, sizeof( frame ) );
 458
 459                 while( ret >= 0 && !got_picture )
 460                 {
 461                         // Read a packet
 462                         ret = av_read_frame( context, &pkt );
 463
 464                         // We only deal with video from the selected video_index
 465                         if ( ret >= 0 && pkt.stream_index == index && pkt.size > 0 )
 466                         {
 467                                 // Decode the image
 468                                 ret = avcodec_decode_video( codec_context, &frame, &got_picture, pkt.data, pkt.size );
 469
 470                                 if ( got_picture )
 471                                 {
 472                                         if ( pkt.pts != AV_NOPTS_VALUE && pkt.pts != 0  )
 473                                                 current_time = ( double )pkt.pts / 1000000.0;
 474                                         else
 475                                                 current_time = real_timecode;
 476
 477                                         // Handle ignore
 478                                         if ( ( int )( current_time * 100 ) < ( int )( real_timecode * 100 ) - 7 )
 479                                         {
 480                                                 ignore = 0;
 481                                                 got_picture = 0;
 482                                         }
 483                                         else if ( current_time >= real_timecode )
 484                                         {
 485                                                 //current_time = real_timecode;
 486                                                 ignore = 0;
 487                                         }
 488                                         else if ( ignore -- )
 489                                         {
 490                                                 got_picture = 0;
 491                                         }
 492                                         mlt_properties_set_int( properties, "top_field_first", frame.top_field_first );
 493                                 }
 494                         }
 495
 496                         // We're finished with this packet regardless
 497                         av_free_packet( &pkt );
 498                 }
 499
 500                 // Now handle the picture if we have one
 501                 if ( got_picture )
 502                 {
 503                         // Get current image and size
 504                         int size = 0;
 505                         uint8_t *image = mlt_properties_get_data( properties, "current_image", &size );
 506
 507                         if ( image == NULL || size != *width * *height * 2 )
 508                         {
 509                                 size = *width * ( *height + 1 ) * 2;
 510                                 image = mlt_pool_alloc( size );
 511                                 mlt_properties_set_data( properties, "current_image", image, size, ( mlt_destructor )mlt_pool_release, NULL );
 512                         }
 513
 514                         *buffer = mlt_pool_alloc( size );
 515
 516                         // EXPERIMENTAL IMAGE NORMALISATIONS
 517                         if ( codec_context->pix_fmt == PIX_FMT_YUV420P )
 518                         {
 519                                 register int i, j;
 520                                 register int half = *width >> 1;
 521                                 register uint8_t *Y = ( ( AVPicture * )&frame )->data[ 0 ];
 522                                 register uint8_t *U = ( ( AVPicture * )&frame )->data[ 1 ];
 523                                 register uint8_t *V = ( ( AVPicture * )&frame )->data[ 2 ];
 524                                 register uint8_t *d = *buffer;
 525                                 register uint8_t *y, *u, *v;
 526
 527                                 i = *height >> 1;
 528                                 while ( i -- )
 529                                 {
 530                                         y = Y;
 531                                         u = U;
 532                                         v = V;
 533                                         j = half;
 534                                         while ( j -- )
 535                                         {
 536                                                 *d ++ = *y ++;
 537                                                 *d ++ = *u ++;
 538                                                 *d ++ = *y ++;
 539                                                 *d ++ = *v ++;
 540                                         }
 541
 542                                         Y += ( ( AVPicture * )&frame )->linesize[ 0 ];
 543                                         y = Y;
 544                                         u = U;
 545                                         v = V;
 546                                         j = half;
 547                                         while ( j -- )
 548                                         {
 549                                                 *d ++ = *y ++;
 550                                                 *d ++ = *u ++;
 551                                                 *d ++ = *y ++;
 552                                                 *d ++ = *v ++;
 553                                         }
 554
 555                                         Y += ( ( AVPicture * )&frame )->linesize[ 0 ];
 556                                         U += ( ( AVPicture * )&frame )->linesize[ 1 ];
 557                                         V += ( ( AVPicture * )&frame )->linesize[ 2 ];
 558                                 }
 559                         }
 560                         else
 561                         {
 562                                 img_convert( output, PIX_FMT_YUV422, (AVPicture *)&frame, codec_context->pix_fmt, *width, *height );
 563                                 memcpy( *buffer, output->data[ 0 ], size );
 564                         }
 565
 566                         memcpy( image, *buffer, size );
 567                         mlt_properties_set_data( frame_properties, "image", *buffer, size, ( mlt_destructor )mlt_pool_release, NULL );
 568
 569                         if ( current_time == 0 && source_fps != 0 )
 570                         {
 571                                 double fps = mlt_properties_get_double( properties, "fps" );
 572                                 current_time = ceil( source_fps * ( double )position / fps ) * ( 1 / source_fps );
 573                                 mlt_properties_set_double( properties, "current_time", current_time );
 574                         }
 575                         else
 576                         {
 577                                 mlt_properties_set_double( properties, "current_time", current_time );
 578                         }
 579                 }
 580         }
 581
 582         // Set the field order property for this frame
 583         mlt_properties_set_int( frame_properties, "top_field_first",
 584                 mlt_properties_get_int( properties, "top_field_first" ) );
 585
 586         // Regardless of speed, we expect to get the next frame (cos we ain't too bright)
 587         mlt_properties_set_position( properties, "video_expected", position + 1 );
 588
 589         // Unlock the mutex now
 590         avformat_unlock( );
 591
 592         return 0;
 593 }
 594
 595 /** Set up video handling.
 596 */
 597
 598 static void producer_set_up_video( mlt_producer this, mlt_frame frame )
 599 {
 600         // Get the properties
 601         mlt_properties properties = mlt_producer_properties( this );
 602
 603         // Fetch the video_context
 604         AVFormatContext *context = mlt_properties_get_data( properties, "video_context", NULL );
 605
 606         // Get the video_index
 607         int index = mlt_properties_get_int( properties, "video_index" );
 608
 609         // Get the frame properties
 610         mlt_properties frame_properties = mlt_frame_properties( frame );
 611
 612         // Lock the mutex now
 613         avformat_lock( );
 614
 615         if ( context != NULL && index != -1 )
 616         {
 617                 // Get the video stream
 618                 AVStream *stream = context->streams[ index ];
 619
 620                 // Get codec context
 621                 AVCodecContext *codec_context = &stream->codec;
 622
 623                 // Get the codec
 624                 AVCodec *codec = mlt_properties_get_data( properties, "video_codec", NULL );
 625
 626                 // Initialise the codec if necessary
 627                 if ( codec == NULL )
 628                 {
 629                         // Find the codec
 630                         codec = avcodec_find_decoder( codec_context->codec_id );
 631
 632                         // If we don't have a codec and we can't initialise it, we can't do much more...
 633                         if ( codec != NULL && avcodec_open( codec_context, codec ) >= 0 )
 634                         {
 635                                 // Now store the codec with its destructor
 636                                 mlt_properties_set_data( properties, "video_codec", codec_context, 0, producer_codec_close, NULL );
 637                         }
 638                         else
 639                         {
 640                                 // Remember that we can't use this later
 641                                 mlt_properties_set_int( properties, "video_index", -1 );
 642                         }
 643                 }
 644
 645                 // No codec, no show...
 646                 if ( codec != NULL )
 647                 {
 648                         double aspect_ratio = 1;
 649                         double source_fps = 0;
 650
 651                         // Set aspect ratio
 652                         if ( codec_context->sample_aspect_ratio.num > 0 )
 653                                 aspect_ratio = av_q2d( codec_context->sample_aspect_ratio );
 654
 655                         mlt_properties_set_double( properties, "aspect_ratio", aspect_ratio );
 656                         //fprintf( stderr, "AVFORMAT: sample aspect %f %dx%d\n", av_q2d( codec_context->sample_aspect_ratio ), codec_context->width, codec_context->height );
 657
 658                         // Determine the fps
 659                         source_fps = ( double )codec_context->frame_rate / ( codec_context->frame_rate_base == 0 ? 1 : codec_context->frame_rate_base );
 660
 661                         // We'll use fps if it's available
 662                         if ( source_fps > 0 && source_fps < 30 )
 663                                 mlt_properties_set_double( properties, "source_fps", source_fps );
 664
 665                         // Set the width and height
 666                         mlt_properties_set_int( frame_properties, "width", codec_context->width );
 667                         mlt_properties_set_int( frame_properties, "height", codec_context->height );
 668
 669                         mlt_frame_push_get_image( frame, producer_get_image );
 670                         mlt_properties_set_data( frame_properties, "avformat_producer", this, 0, NULL, NULL );
 671                 }
 672                 else
 673                 {
 674                         mlt_properties_set_int( frame_properties, "test_image", 1 );
 675                 }
 676         }
 677         else
 678         {
 679                 mlt_properties_set_int( frame_properties, "test_image", 1 );
 680         }
 681
 682         // Unlock the mutex now
 683         avformat_unlock( );
 684 }
 685
 686 /** Get the audio from a frame.
 687 */
 688
 689 static int producer_get_audio( mlt_frame frame, int16_t **buffer, mlt_audio_format *format, int *frequency, int *channels, int *samples )
 690 {
 691         // Get the properties from the frame
 692         mlt_properties frame_properties = mlt_frame_properties( frame );
 693
 694         // Obtain the frame number of this frame
 695         mlt_position position = mlt_properties_get_position( frame_properties, "avformat_position" );
 696
 697         // Get the producer
 698         mlt_producer this = mlt_properties_get_data( frame_properties, "avformat_producer", NULL );
 699
 700         // Get the producer properties
 701         mlt_properties properties = mlt_producer_properties( this );
 702
 703         // Fetch the audio_context
 704         AVFormatContext *context = mlt_properties_get_data( properties, "audio_context", NULL );
 705
 706         // Get the audio_index
 707         int index = mlt_properties_get_int( properties, "audio_index" );
 708
 709         // Get the seekable status
 710         int seekable = mlt_properties_get_int( properties, "seekable" );
 711
 712         // Obtain the expected frame numer
 713         mlt_position expected = mlt_properties_get_position( properties, "audio_expected" );
 714
 715         // Obtain the resample context if it exists (not always needed)
 716         ReSampleContext *resample = mlt_properties_get_data( properties, "audio_resample", NULL );
 717
 718         // Obtain the audio buffer
 719         int16_t *audio_buffer = mlt_properties_get_data( properties, "audio_buffer", NULL );
 720
 721         // Get amount of audio used
 722         int audio_used =  mlt_properties_get_int( properties, "audio_used" );
 723
 724         // Calculate the real time code
 725         double real_timecode = producer_time_of_frame( this, position );
 726
 727         // Get the audio stream
 728         AVStream *stream = context->streams[ index ];
 729
 730         // Get codec context
 731         AVCodecContext *codec_context = &stream->codec;
 732
 733         // Packet
 734         AVPacket pkt;
 735
 736         // Number of frames to ignore (for ffwd)
 737         int ignore = 0;
 738
 739         // Flag for paused (silence)
 740         int paused = 0;
 741
 742         // Lock the mutex now
 743         avformat_lock( );
 744
 745         // Check for resample and create if necessary
 746         if ( resample == NULL && codec_context->channels <= 2 )
 747         {
 748                 // Create the resampler
 749                 resample = audio_resample_init( *channels, codec_context->channels, *frequency, codec_context->sample_rate );
 750
 751                 // And store it on properties
 752                 mlt_properties_set_data( properties, "audio_resample", resample, 0, ( mlt_destructor )audio_resample_close, NULL );
 753         }
 754         else if ( resample == NULL )
 755         {
 756                 *channels = codec_context->channels;
 757                 *frequency = codec_context->sample_rate;
 758         }
 759
 760         // Check for audio buffer and create if necessary
 761         if ( audio_buffer == NULL )
 762         {
 763                 // Allocate the audio buffer
 764                 audio_buffer = mlt_pool_alloc( AVCODEC_MAX_AUDIO_FRAME_SIZE * sizeof( int16_t ) );
 765
 766                 // And store it on properties for reuse
 767                 mlt_properties_set_data( properties, "audio_buffer", audio_buffer, 0, ( mlt_destructor )mlt_pool_release, NULL );
 768         }
 769
 770         // Seek if necessary
 771         if ( position != expected )
 772         {
 773                 if ( position + 1 == expected )
 774                 {
 775                         // We're paused - silence required
 776                         paused = 1;
 777                 }
 778                 else if ( position > expected && ( position - expected ) < 250 )
 779                 {
 780                         // Fast forward - seeking is inefficient for small distances - just ignore following frames
 781                         ignore = position - expected;
 782                 }
 783                 else
 784                 {
 785                         // Set to the real timecode
 786                         if ( !seekable || av_seek_frame( context, -1, context->start_time + real_timecode * 1000000.0 ) != 0 )
 787                                 paused = 1;
 788
 789                         // Clear the usage in the audio buffer
 790                         audio_used = 0;
 791                 }
 792         }
 793
 794         // Get the audio if required
 795         if ( !paused )
 796         {
 797                 int ret = 0;
 798                 int got_audio = 0;
 799                 int16_t *temp = mlt_pool_alloc( sizeof( int16_t ) * AVCODEC_MAX_AUDIO_FRAME_SIZE );
 800
 801                 memset( &pkt, 0, sizeof( pkt ) );
 802
 803                 while( ret >= 0 && !got_audio )
 804                 {
 805                         // Check if the buffer already contains the samples required
 806                         if ( audio_used >= *samples && ignore == 0 )
 807                         {
 808                                 got_audio = 1;
 809                                 break;
 810                         }
 811
 812                         // Read a packet
 813                         ret = av_read_frame( context, &pkt );
 814
 815                 int len = pkt.size;
 816                 uint8_t *ptr = pkt.data;
 817                         int data_size;
 818
 819                         // We only deal with audio from the selected audio_index
 820                         while ( ptr != NULL && ret >= 0 && pkt.stream_index == index && len > 0 )
 821                         {
 822                                 // Decode the audio
 823                                 ret = avcodec_decode_audio( codec_context, temp, &data_size, ptr, len );
 824
 825                                 if ( ret < 0 )
 826                                 {
 827                                         ret = 0;
 828                                         break;
 829                                 }
 830
 831                                 len -= ret;
 832                                 ptr += ret;
 833
 834                                 if ( data_size > 0 )
 835                                 {
 836                                         if ( resample != NULL )
 837                                         {
 838                                                 audio_used += audio_resample( resample, &audio_buffer[ audio_used * *channels ], temp, data_size / ( codec_context->channels * sizeof( int16_t ) ) );
 839                                         }
 840                                         else
 841                                         {
 842                                                 memcpy( &audio_buffer[ audio_used * *channels ], temp, data_size );
 843                                                 audio_used += data_size / ( codec_context->channels * sizeof( int16_t ) );
 844                                         }
 845
 846                                         // Handle ignore
 847                                         while ( ignore && audio_used > *samples )
 848                                         {
 849                                                 ignore --;
 850                                                 audio_used -= *samples;
 851                                                 memmove( audio_buffer, &audio_buffer[ *samples * *channels ], audio_used * sizeof( int16_t ) );
 852                                         }
 853                                 }
 854
 855                                 // If we're behind, ignore this packet
 856                                 float current_pts = (float)pkt.pts / 1000000.0;
 857                                 double discrepancy = mlt_properties_get_double( properties, "discrepancy" );
 858                                 if ( current_pts != 0 && real_timecode != 0 )
 859                                 {
 860                                         if ( discrepancy != 1 )
 861                                                 discrepancy = ( discrepancy + ( real_timecode / current_pts ) ) / 2;
 862                                         else
 863                                                 discrepancy = real_timecode / current_pts;
 864                                         if ( discrepancy > 0.9 && discrepancy < 1.1 )
 865                                                 discrepancy = 1.0;
 866                                         else
 867                                                 discrepancy = floor( discrepancy + 0.5 );
 868
 869                                         if ( discrepancy == 0 )
 870                                                 discrepancy = 1.0;
 871
 872                                         mlt_properties_set_double( properties, "discrepancy", discrepancy );
 873                                 }
 874
 875                                 if ( seekable && ( !ignore && discrepancy * current_pts <= ( real_timecode - 0.02 ) ) )
 876                                         ignore = 1;
 877                         }
 878
 879                         // We're finished with this packet regardless
 880                         av_free_packet( &pkt );
 881                 }
 882
 883                 *buffer = mlt_pool_alloc( *samples * *channels * sizeof( int16_t ) );
 884                 mlt_properties_set_data( frame_properties, "audio", *buffer, 0, ( mlt_destructor )mlt_pool_release, NULL );
 885
 886                 // Now handle the audio if we have enough
 887                 if ( audio_used >= *samples )
 888                 {
 889                         memcpy( *buffer, audio_buffer, *samples * *channels * sizeof( int16_t ) );
 890                         audio_used -= *samples;
 891                         memmove( audio_buffer, &audio_buffer[ *samples * *channels ], audio_used * *channels * sizeof( int16_t ) );
 892                 }
 893                 else
 894                 {
 895                         memset( *buffer, 0, *samples * *channels * sizeof( int16_t ) );
 896                 }
 897
 898                 // Store the number of audio samples still available
 899                 mlt_properties_set_int( properties, "audio_used", audio_used );
 900
 901                 // Release the temporary audio
 902                 mlt_pool_release( temp );
 903         }
 904         else
 905         {
 906                 // Get silence and don't touch the context
 907                 frame->get_audio = NULL;
 908                 mlt_frame_get_audio( frame, buffer, format, frequency, channels, samples );
 909         }
 910
 911         // Regardless of speed (other than paused), we expect to get the next frame
 912         if ( !paused )
 913                 mlt_properties_set_position( properties, "audio_expected", position + 1 );
 914
 915         // Unlock the mutex now
 916         avformat_unlock( );
 917
 918         return 0;
 919 }
 920
 921 /** Set up audio handling.
 922 */
 923
 924 static void producer_set_up_audio( mlt_producer this, mlt_frame frame )
 925 {
 926         // Get the properties
 927         mlt_properties properties = mlt_producer_properties( this );
 928
 929         // Fetch the audio_context
 930         AVFormatContext *context = mlt_properties_get_data( properties, "audio_context", NULL );
 931
 932         // Get the audio_index
 933         int index = mlt_properties_get_int( properties, "audio_index" );
 934
 935         // Lock the mutex now
 936         avformat_lock( );
 937
 938         // Deal with audio context
 939         if ( context != NULL && index != -1 )
 940         {
 941                 // Get the frame properties
 942                 mlt_properties frame_properties = mlt_frame_properties( frame );
 943
 944                 // Get the audio stream
 945                 AVStream *stream = context->streams[ index ];
 946
 947                 // Get codec context
 948                 AVCodecContext *codec_context = &stream->codec;
 949
 950                 // Get the codec
 951                 AVCodec *codec = mlt_properties_get_data( properties, "audio_codec", NULL );
 952
 953                 // Initialise the codec if necessary
 954                 if ( codec == NULL )
 955                 {
 956                         // Find the codec
 957                         codec = avcodec_find_decoder( codec_context->codec_id );
 958
 959                         // If we don't have a codec and we can't initialise it, we can't do much more...
 960                         if ( codec != NULL && avcodec_open( codec_context, codec ) >= 0 )
 961                         {
 962                                 // Now store the codec with its destructor
 963                                 mlt_properties_set_data( properties, "audio_codec", codec_context, 0, producer_codec_close, NULL );
 964
 965                         }
 966                         else
 967                         {
 968                                 // Remember that we can't use this later
 969                                 mlt_properties_set_int( properties, "audio_index", -1 );
 970                         }
 971                 }
 972
 973                 // No codec, no show...
 974                 if ( codec != NULL )
 975                 {
 976                         frame->get_audio = producer_get_audio;
 977                         mlt_properties_set_data( frame_properties, "avformat_producer", this, 0, NULL, NULL );
 978                 }
 979         }
 980
 981         // Unlock the mutex now
 982         avformat_unlock( );
 983 }
 984
 985 /** Our get frame implementation.
 986 */
 987
 988 static int producer_get_frame( mlt_producer this, mlt_frame_ptr frame, int index )
 989 {
 990         // Create an empty frame
 991         *frame = mlt_frame_init( );
 992
 993         // Update timecode on the frame we're creating
 994         mlt_frame_set_position( *frame, mlt_producer_position( this ) );
 995
 996         // Set the position of this producer
 997         mlt_properties_set_position( mlt_frame_properties( *frame ), "avformat_position", mlt_producer_get_in( this ) + mlt_producer_position( this ) );
 998
 999         // Set up the video
1000         producer_set_up_video( this, *frame );
1001
1002         // Set up the audio
1003         producer_set_up_audio( this, *frame );
1004
1005         // Set the aspect_ratio
1006         mlt_properties_set_double( mlt_frame_properties( *frame ), "aspect_ratio", mlt_properties_get_double( mlt_producer_properties( this ), "aspect_ratio" ) );
1007
1008         // Calculate the next timecode
1009         mlt_producer_prepare_next( this );
1010
1011         return 0;
1012 }