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[mlt] / 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 #if 0
45 void *av_malloc( unsigned int size )
46 {
47         return mlt_pool_alloc( size );
48 }
49
50 void *av_realloc( void *ptr, unsigned int size )
51 {
52         return mlt_pool_realloc( ptr, size );
53 }
54
55 void av_free( void *ptr )
56 {
57         return mlt_pool_release( ptr );
58 }
59 #endif
60
61 /** Constructor for libavformat.
62 */
63
64 mlt_producer producer_avformat_init( char *file )
65 {
66         mlt_producer this = NULL;
67
68         // Check that we have a non-NULL argument
69         if ( file != NULL )
70         {
71                 // Construct the producer
72                 this = calloc( 1, sizeof( struct mlt_producer_s ) );
73
74                 // Initialise it
75                 if ( mlt_producer_init( this, NULL ) == 0 )
76                 {
77                         // Get the properties
78                         mlt_properties properties = mlt_producer_properties( this );
79
80                         // Set the resource property (required for all producers)
81                         mlt_properties_set( properties, "resource", file );
82
83                         // TEST: audio sync tweaking
84                         mlt_properties_set_double( properties, "discrepancy", 1 );
85
86                         // Register our get_frame implementation
87                         this->get_frame = producer_get_frame;
88
89                         // Initialise avformat if necessary
90                         if ( avformat_initialised == 0 )
91                         {
92                                 avformat_initialised = 1;
93                                 pthread_mutex_init( &avformat_mutex, NULL );
94                                 av_register_all( );
95                         }
96
97                         // Open the file
98                         if ( producer_open( this, file ) != 0 )
99                         {
100                                 // Clean up
101                                 mlt_producer_close( this );
102                                 this = NULL;
103                         }
104                 }
105         }
106
107         return this;
108 }
109
110 /** Find the default streams.
111 */
112
113 static void find_default_streams( AVFormatContext *context, int *audio_index, int *video_index )
114 {
115         int i;
116
117         // Allow for multiple audio and video streams in the file and select first of each (if available)
118         for( i = 0; i < context->nb_streams; i++ ) 
119         {
120                 // Get the codec context
121                 AVCodecContext *codec_context = &context->streams[ i ]->codec;
122
123                 // Determine the type and obtain the first index of each type
124                 switch( codec_context->codec_type ) 
125                 {
126                         case CODEC_TYPE_VIDEO:
127                                 if ( *video_index < 0 )
128                                         *video_index = i;
129                                 break;
130                         case CODEC_TYPE_AUDIO:
131                                 if ( *audio_index < 0 )
132                                         *audio_index = i;
133                                 break;
134                         default:
135                                 break;
136                 }
137         }
138 }
139
140 /** Producer file destructor.
141 */
142
143 static void producer_file_close( void *context )
144 {
145         if ( context != NULL )
146         {
147                 // Lock the mutex now
148                 pthread_mutex_lock( &avformat_mutex );
149
150                 // Close the file
151                 av_close_input_file( context );
152
153                 // Unlock the mutex now
154                 pthread_mutex_unlock( &avformat_mutex );
155         }
156 }
157
158 /** Producer file destructor.
159 */
160
161 static void producer_codec_close( void *codec )
162 {
163         if ( codec != NULL )
164         {
165                 // Lock the mutex now
166                 pthread_mutex_lock( &avformat_mutex );
167
168                 // Close the file
169                 avcodec_close( codec );
170
171                 // Unlock the mutex now
172                 pthread_mutex_unlock( &avformat_mutex );
173         }
174 }
175
176 /** Open the file.
177 */
178
179 static int producer_open( mlt_producer this, char *file )
180 {
181         // Return an error code (0 == no error)
182         int error = 0;
183
184         // Context for avformat
185         AVFormatContext *context = NULL;
186
187         // Get the properties
188         mlt_properties properties = mlt_producer_properties( this );
189
190         // We will treat everything with the producer fps
191         double fps = mlt_properties_get_double( properties, "fps" );
192
193         // Lock the mutex now
194         pthread_mutex_lock( &avformat_mutex );
195         
196         // If "MRL", then create AVInputFormat
197         AVInputFormat *format = NULL;
198         AVFormatParameters *params = NULL;
199         char *standard = NULL;
200         char *mrl = strchr( file, ':' );
201         
202         // Only if there is not a protocol specification that avformat can handle
203         if ( mrl && !url_exist( file ) )
204         {
205                 // 'file' becomes format abbreviation
206                 mrl[0] = 0;
207         
208                 // Lookup the format
209                 format = av_find_input_format( file );
210                 
211                 // Eat the format designator
212                 file = ++mrl;
213                 
214                 if ( format )
215                 {
216                         // Allocate params
217                         params = calloc( sizeof( AVFormatParameters ), 1 );
218                         
219                         // These are required by video4linux (defaults)
220                         params->width = 640;
221                         params->height = 480;
222                         params->frame_rate = 25;
223                         params->frame_rate_base = 1;
224                         params->device = file;
225                         params->channels = 2;
226                         params->sample_rate = 48000;
227                 }
228                 
229                 // Parse out params
230                 mrl = strchr( file, '?' );
231                 while ( mrl )
232                 {
233                         mrl[0] = 0;
234                         char *name = strdup( ++mrl );
235                         char *value = strchr( name, ':' );
236                         if ( value )
237                         {
238                                 value[0] = 0;
239                                 value++;
240                                 char *t = strchr( value, '&' );
241                                 if ( t )
242                                         t[0] = 0;
243                                 if ( !strcmp( name, "frame_rate" ) )
244                                         params->frame_rate = atoi( value );
245                                 else if ( !strcmp( name, "frame_rate_base" ) )
246                                         params->frame_rate_base = atoi( value );
247                                 else if ( !strcmp( name, "sample_rate" ) )
248                                         params->sample_rate = atoi( value );
249                                 else if ( !strcmp( name, "channels" ) )
250                                         params->channels = atoi( value );
251                                 else if ( !strcmp( name, "width" ) )
252                                         params->width = atoi( value );
253                                 else if ( !strcmp( name, "height" ) )
254                                         params->height = atoi( value );
255                                 else if ( !strcmp( name, "standard" ) )
256                                 {
257                                         standard = strdup( value );
258                                         params->standard = standard;
259                                 }
260                         }
261                         free( name );
262                         mrl = strchr( mrl, '&' );
263                 }
264         }
265
266         // Now attempt to open the file
267         error = av_open_input_file( &context, file, format, 0, params );
268         error = error < 0;
269         
270         // Cleanup AVFormatParameters
271         free( standard );
272         free( params );
273
274         // If successful, then try to get additional info
275         if ( error == 0 )
276         {
277                 // Get the stream info
278                 error = av_find_stream_info( context ) < 0;
279
280                 // Continue if no error
281                 if ( error == 0 )
282                 {
283                         // We will default to the first audio and video streams found
284                         int audio_index = -1;
285                         int video_index = -1;
286
287                         // Now set properties where we can (use default unknowns if required)
288                         if ( context->duration != AV_NOPTS_VALUE ) 
289                         {
290                                 // This isn't going to be accurate for all formats
291                                 mlt_position frames = ( mlt_position )( ( ( double )context->duration / ( double )AV_TIME_BASE ) * fps );
292                                 mlt_properties_set_position( properties, "out", frames - 2 );
293                                 mlt_properties_set_position( properties, "length", frames - 1 );
294                         }
295
296                         // Find default audio and video streams
297                         find_default_streams( context, &audio_index, &video_index );
298
299                         // Store selected audio and video indexes on properties
300                         mlt_properties_set_int( properties, "audio_index", audio_index );
301                         mlt_properties_set_int( properties, "video_index", video_index );
302                         
303                         // We're going to cheat here - for a/v files, we will have two contexts (reasoning will be clear later)
304                         if ( audio_index != -1 && video_index != -1 )
305                         {
306                                 // We'll use the open one as our video_context
307                                 mlt_properties_set_data( properties, "video_context", context, 0, producer_file_close, NULL );
308
309                                 // And open again for our audio context
310                                 av_open_input_file( &context, file, NULL, 0, NULL );
311                                 av_find_stream_info( context );
312
313                                 // Audio context
314                                 mlt_properties_set_data( properties, "audio_context", context, 0, producer_file_close, NULL );
315                         }
316                         else if ( video_index != -1 )
317                         {
318                                 // We only have a video context
319                                 mlt_properties_set_data( properties, "video_context", context, 0, producer_file_close, NULL );
320                         }
321                         else if ( audio_index != -1 )
322                         {
323                                 // We only have an audio context
324                                 mlt_properties_set_data( properties, "audio_context", context, 0, producer_file_close, NULL );
325                         }
326                         else
327                         {
328                                 // Something has gone wrong
329                                 error = -1;
330                         }
331                 }
332         }
333
334         // Unlock the mutex now
335         pthread_mutex_unlock( &avformat_mutex );
336
337         return error;
338 }
339
340 /** Convert a frame position to a time code.
341 */
342
343 static double producer_time_of_frame( mlt_producer this, mlt_position position )
344 {
345         // Get the properties
346         mlt_properties properties = mlt_producer_properties( this );
347
348         // Obtain the fps
349         double fps = mlt_properties_get_double( properties, "fps" );
350
351         // Do the calc
352         return ( double )position / fps;
353 }
354
355 /** Get an image from a frame.
356 */
357
358 static int producer_get_image( mlt_frame frame, uint8_t **buffer, mlt_image_format *format, int *width, int *height, int writable )
359 {
360         // Get the properties from the frame
361         mlt_properties frame_properties = mlt_frame_properties( frame );
362
363         // Obtain the frame number of this frame
364         mlt_position position = mlt_properties_get_position( frame_properties, "avformat_position" );
365
366         // Get the producer 
367         mlt_producer this = mlt_properties_get_data( frame_properties, "avformat_producer", NULL );
368
369         // Get the producer properties
370         mlt_properties properties = mlt_producer_properties( this );
371
372         // Fetch the video_context
373         AVFormatContext *context = mlt_properties_get_data( properties, "video_context", NULL );
374
375         // Get the video_index
376         int index = mlt_properties_get_int( properties, "video_index" );
377
378         // Obtain the expected frame numer
379         mlt_position expected = mlt_properties_get_position( properties, "video_expected" );
380
381         // Calculate the real time code
382         double real_timecode = producer_time_of_frame( this, position );
383
384         // Get the video stream
385         AVStream *stream = context->streams[ index ];
386
387         // Get codec context
388         AVCodecContext *codec_context = &stream->codec;
389
390         // Packet
391         AVPacket pkt;
392
393         // Get the conversion frame
394         AVPicture *output = mlt_properties_get_data( properties, "video_output_frame", NULL );
395
396         // Special case pause handling flag
397         int paused = 0;
398
399         // Special case ffwd handling
400         int ignore = 0;
401
402         // Current time calcs
403         double current_time = mlt_properties_get_double( properties, "current_time" );
404
405         // We may want to use the source fps if available
406         double source_fps = mlt_properties_get_double( properties, "source_fps" );
407
408         // Set the result arguments that we know here (only *buffer is now required)
409         *format = mlt_image_yuv422;
410         *width = codec_context->width;
411         *height = codec_context->height;
412
413         // Set this on the frame properties
414         mlt_properties_set_int( frame_properties, "width", *width );
415         mlt_properties_set_int( frame_properties, "height", *height );
416
417         // Lock the mutex now
418         pthread_mutex_lock( &avformat_mutex );
419
420         // Construct an AVFrame for YUV422 conversion
421         if ( output == NULL )
422         {
423                 int size = avpicture_get_size( PIX_FMT_YUV422, *width, *height );
424                 size += *width * 2;
425                 uint8_t *buf = mlt_pool_alloc( size );
426                 output = mlt_pool_alloc( sizeof( AVPicture ) );
427                 //memset( output, 0, sizeof( AVPicture ) );
428                 avpicture_fill( output, buf, PIX_FMT_YUV422, *width, *height );
429                 mlt_properties_set_data( properties, "video_output_frame", output, 0, ( mlt_destructor )mlt_pool_release, NULL );
430                 mlt_properties_set_data( properties, "video_output_buffer", buf, 0, ( mlt_destructor )mlt_pool_release, NULL );
431         }
432
433         // Seek if necessary
434         if ( position != expected )
435         {
436                 if ( position + 1 == expected )
437                 {
438                         // We're paused - use last image
439                         paused = 1;
440                 }
441                 else if ( position > expected && ( position - expected ) < 250 )
442                 {
443                         // Fast forward - seeking is inefficient for small distances - just ignore following frames
444                         ignore = position - expected;
445                 }
446                 else
447                 {
448                         // Set to the real timecode
449                         av_seek_frame( context, -1, real_timecode * 1000000.0 );
450         
451                         // Remove the cached info relating to the previous position
452                         mlt_properties_set_double( properties, "current_time", real_timecode );
453                         mlt_properties_set_data( properties, "current_image", NULL, 0, NULL, NULL );
454                 }
455         }
456         
457         // Duplicate the last image if necessary
458         if ( mlt_properties_get_data( properties, "current_image", NULL ) != NULL &&
459                  ( paused || mlt_properties_get_double( properties, "current_time" ) >= real_timecode ) )
460         {
461                 // Get current image and size
462                 int size = 0;
463                 uint8_t *image = mlt_properties_get_data( properties, "current_image", &size );
464
465                 // Duplicate it
466                 *buffer = mlt_pool_alloc( size );
467                 memcpy( *buffer, image, size );
468
469                 // Set this on the frame properties
470                 mlt_properties_set_data( frame_properties, "image", *buffer, size, ( mlt_destructor )mlt_pool_release, NULL );
471         }
472         else
473         {
474                 int ret = 0;
475                 int got_picture = 0;
476                 AVFrame frame;
477
478                 memset( &pkt, 0, sizeof( pkt ) );
479                 memset( &frame, 0, sizeof( frame ) );
480
481                 while( ret >= 0 && !got_picture )
482                 {
483                         // Read a packet
484                         ret = av_read_frame( context, &pkt );
485
486                         // We only deal with video from the selected video_index
487                         if ( ret >= 0 && pkt.stream_index == index && pkt.size > 0 )
488                         {
489                                 // Decode the image
490                                 ret = avcodec_decode_video( codec_context, &frame, &got_picture, pkt.data, pkt.size );
491
492                                 if ( got_picture )
493                                 {
494                                         if ( pkt.pts != AV_NOPTS_VALUE && pkt.pts != 0  )
495                                         {
496                                                 current_time = ( double )pkt.pts / 1000000.0;
497                                         }
498                                         else
499                                                 current_time = real_timecode;
500
501                                         // Handle ignore
502                                         if ( current_time < real_timecode )
503                                         {
504                                                 ignore = 0;
505                                                 got_picture = 0;
506                                         }
507                                         else if ( current_time >= real_timecode )
508                                         {
509                                                 //current_time = real_timecode;
510                                                 ignore = 0;
511                                         }
512                                         else if ( ignore -- )
513                                         {
514                                                 got_picture = 0;
515                                         }
516                                 }
517                         }
518
519                         // We're finished with this packet regardless
520                         av_free_packet( &pkt );
521                 }
522
523                 // Now handle the picture if we have one
524                 if ( got_picture )
525                 {
526                         // Get current image and size
527                         int size = 0;
528                         uint8_t *image = mlt_properties_get_data( properties, "current_image", &size );
529
530                         if ( image == NULL || size != *width * *height * 2 )
531                         {
532                                 size = *width * ( *height + 1 ) * 2;
533                                 image = mlt_pool_alloc( size );
534                                 mlt_properties_set_data( properties, "current_image", image, size, ( mlt_destructor )mlt_pool_release, NULL );
535                         }
536
537                         *buffer = mlt_pool_alloc( size );
538
539                         // EXPERIMENTAL IMAGE NORMALISATIONS
540                         if ( codec_context->pix_fmt == PIX_FMT_YUV420P )
541                         {
542                                 register int i, j;
543                                 register int half = *width >> 1;
544                                 register uint8_t *Y = ( ( AVPicture * )&frame )->data[ 0 ];
545                                 register uint8_t *U = ( ( AVPicture * )&frame )->data[ 1 ];
546                                 register uint8_t *V = ( ( AVPicture * )&frame )->data[ 2 ];
547                                 register uint8_t *d = *buffer;
548                                 register uint8_t *y, *u, *v;
549
550                                 i = *height >> 1;
551                                 while ( i -- )
552                                 {
553                                         y = Y;
554                                         u = U;
555                                         v = V;
556                                         j = half;
557                                         while ( j -- )
558                                         {
559                                                 *d ++ = *y ++;
560                                                 *d ++ = *u ++;
561                                                 *d ++ = *y ++;
562                                                 *d ++ = *v ++;
563                                         }
564
565                                         Y += ( ( AVPicture * )&frame )->linesize[ 0 ];
566                                         y = Y;
567                                         u = U;
568                                         v = V;
569                                         j = half;
570                                         while ( j -- )
571                                         {
572                                                 *d ++ = *y ++;
573                                                 *d ++ = *u ++;
574                                                 *d ++ = *y ++;
575                                                 *d ++ = *v ++;
576                                         }
577
578                                         Y += ( ( AVPicture * )&frame )->linesize[ 0 ];
579                                         U += ( ( AVPicture * )&frame )->linesize[ 1 ];
580                                         V += ( ( AVPicture * )&frame )->linesize[ 2 ];
581                                 }
582                         }
583                         else
584                         {
585                                 img_convert( output, PIX_FMT_YUV422, (AVPicture *)&frame, codec_context->pix_fmt, *width, *height );
586                                 memcpy( *buffer, output->data[ 0 ], size );
587                         }
588
589                         memcpy( image, *buffer, size );
590                         mlt_properties_set_data( frame_properties, "image", *buffer, size, ( mlt_destructor )mlt_pool_release, NULL );
591
592                         if ( current_time == 0 && source_fps != 0 )
593                         {
594                                 double fps = mlt_properties_get_double( properties, "fps" );
595                                 current_time = ceil( source_fps * ( double )position / fps ) * ( 1 / source_fps );
596                                 mlt_properties_set_double( properties, "current_time", current_time );
597                         }
598                         else
599                         {
600                                 mlt_properties_set_double( properties, "current_time", current_time );
601                         }
602                 }
603         }
604
605         // Regardless of speed, we expect to get the next frame (cos we ain't too bright)
606         mlt_properties_set_position( properties, "video_expected", position + 1 );
607
608         // Unlock the mutex now
609         pthread_mutex_unlock( &avformat_mutex );
610
611         return 0;
612 }
613
614 /** Set up video handling.
615 */
616
617 static void producer_set_up_video( mlt_producer this, mlt_frame frame )
618 {
619         // Get the properties
620         mlt_properties properties = mlt_producer_properties( this );
621
622         // Fetch the video_context
623         AVFormatContext *context = mlt_properties_get_data( properties, "video_context", NULL );
624
625         // Get the video_index
626         int index = mlt_properties_get_int( properties, "video_index" );
627
628         // Get the frame properties
629         mlt_properties frame_properties = mlt_frame_properties( frame );
630
631         // Lock the mutex now
632         pthread_mutex_lock( &avformat_mutex );
633
634         if ( context != NULL && index != -1 )
635         {
636                 // Get the video stream
637                 AVStream *stream = context->streams[ index ];
638
639                 // Get codec context
640                 AVCodecContext *codec_context = &stream->codec;
641
642                 // Get the codec
643                 AVCodec *codec = mlt_properties_get_data( properties, "video_codec", NULL );
644
645                 // Initialise the codec if necessary
646                 if ( codec == NULL )
647                 {
648                         // Find the codec
649                         codec = avcodec_find_decoder( codec_context->codec_id );
650
651                         // If we don't have a codec and we can't initialise it, we can't do much more...
652                         if ( codec != NULL && avcodec_open( codec_context, codec ) >= 0 )
653                         {
654                                 // Now store the codec with its destructor
655                                 mlt_properties_set_data( properties, "video_codec", codec_context, 0, producer_codec_close, NULL );
656                         }
657                         else
658                         {
659                                 // Remember that we can't use this later
660                                 mlt_properties_set_int( properties, "video_index", -1 );
661                         }
662                 }
663
664                 // No codec, no show...
665                 if ( codec != NULL )
666                 {
667                         double aspect_ratio = 1;
668                         double source_fps = 0;
669
670                         // Set aspect ratio
671                         if ( codec_context->sample_aspect_ratio.num > 0 )
672                                 aspect_ratio = av_q2d( codec_context->sample_aspect_ratio );
673
674                         mlt_properties_set_double( properties, "aspect_ratio", aspect_ratio );
675                         //fprintf( stderr, "AVFORMAT: sample aspect %f %dx%d\n", av_q2d( codec_context->sample_aspect_ratio ), codec_context->width, codec_context->height );
676
677                         // Determine the fps
678                         source_fps = ( double )codec_context->frame_rate / ( codec_context->frame_rate_base == 0 ? 1 : codec_context->frame_rate_base );
679
680                         // We'll use fps if it's available
681                         if ( source_fps > 0 && source_fps < 30 )
682                                 mlt_properties_set_double( properties, "source_fps", source_fps );
683                         
684                         // Set the width and height
685                         mlt_properties_set_int( frame_properties, "width", codec_context->width );
686                         mlt_properties_set_int( frame_properties, "height", codec_context->height );
687
688                         mlt_frame_push_get_image( frame, producer_get_image );
689                         mlt_properties_set_data( frame_properties, "avformat_producer", this, 0, NULL, NULL );
690                 }
691                 else
692                 {
693                         mlt_properties_set_int( frame_properties, "test_image", 1 );
694                 }
695         }
696         else
697         {
698                 mlt_properties_set_int( frame_properties, "test_image", 1 );
699         }
700
701         // Unlock the mutex now
702         pthread_mutex_unlock( &avformat_mutex );
703 }
704
705 /** Get the audio from a frame.
706 */
707
708 static int producer_get_audio( mlt_frame frame, int16_t **buffer, mlt_audio_format *format, int *frequency, int *channels, int *samples )
709 {
710         // Get the properties from the frame
711         mlt_properties frame_properties = mlt_frame_properties( frame );
712
713         // Obtain the frame number of this frame
714         mlt_position position = mlt_properties_get_position( frame_properties, "avformat_position" );
715
716         // Get the producer 
717         mlt_producer this = mlt_properties_get_data( frame_properties, "avformat_producer", NULL );
718
719         // Get the producer properties
720         mlt_properties properties = mlt_producer_properties( this );
721
722         // Fetch the audio_context
723         AVFormatContext *context = mlt_properties_get_data( properties, "audio_context", NULL );
724
725         // Get the audio_index
726         int index = mlt_properties_get_int( properties, "audio_index" );
727
728         // Obtain the expected frame numer
729         mlt_position expected = mlt_properties_get_position( properties, "audio_expected" );
730
731         // Obtain the resample context if it exists (not always needed)
732         ReSampleContext *resample = mlt_properties_get_data( properties, "audio_resample", NULL );
733
734         // Obtain the audio buffer
735         int16_t *audio_buffer = mlt_properties_get_data( properties, "audio_buffer", NULL );
736
737         // Get amount of audio used
738         int audio_used =  mlt_properties_get_int( properties, "audio_used" );
739
740         // Calculate the real time code
741         double real_timecode = producer_time_of_frame( this, position );
742
743         // Get the audio stream
744         AVStream *stream = context->streams[ index ];
745
746         // Get codec context
747         AVCodecContext *codec_context = &stream->codec;
748
749         // Packet
750         AVPacket pkt;
751
752         // Number of frames to ignore (for ffwd)
753         int ignore = 0;
754
755         // Flag for paused (silence) 
756         int paused = 0;
757         int locked = 0;
758
759         // Lock the mutex now
760         pthread_mutex_lock( &avformat_mutex );
761
762         // Check for resample and create if necessary
763         if ( resample == NULL )
764         {
765                 // Create the resampler
766                 resample = audio_resample_init( *channels, codec_context->channels, *frequency, codec_context->sample_rate );
767
768                 // And store it on properties
769                 mlt_properties_set_data( properties, "audio_resample", resample, 0, ( mlt_destructor )audio_resample_close, NULL );
770         }
771
772         // Check for audio buffer and create if necessary
773         if ( audio_buffer == NULL )
774         {
775                 // Allocate the audio buffer
776                 audio_buffer = mlt_pool_alloc( AVCODEC_MAX_AUDIO_FRAME_SIZE * sizeof( int16_t ) );
777
778                 // And store it on properties for reuse
779                 mlt_properties_set_data( properties, "audio_buffer", audio_buffer, 0, ( mlt_destructor )mlt_pool_release, NULL );
780         }
781
782         // Seek if necessary
783         if ( position != expected )
784         {
785                 if ( position + 1 == expected )
786                 {
787                         // We're paused - silence required
788                         paused = 1;
789                 }
790                 else if ( position > expected && ( position - expected ) < 250 )
791                 {
792                         // Fast forward - seeking is inefficient for small distances - just ignore following frames
793                         ignore = position - expected;
794                 }
795                 else
796                 {
797                         // Set to the real timecode
798                         av_seek_frame( context, -1, real_timecode * 1000000.0 );
799
800                         // Clear the usage in the audio buffer
801                         audio_used = 0;
802
803                         locked = 1;
804                 }
805         }
806
807         // Get the audio if required
808         if ( !paused )
809         {
810                 int ret = 0;
811                 int got_audio = 0;
812                 int16_t *temp = mlt_pool_alloc( sizeof( int16_t ) * AVCODEC_MAX_AUDIO_FRAME_SIZE );
813
814                 memset( &pkt, 0, sizeof( pkt ) );
815
816                 while( ret >= 0 && !got_audio )
817                 {
818                         // Check if the buffer already contains the samples required
819                         if ( audio_used >= *samples && ignore == 0 )
820                         {
821                                 got_audio = 1;
822                                 break;
823                         }
824
825                         // Read a packet
826                         ret = av_read_frame( context, &pkt );
827
828                 int len = pkt.size;
829                 uint8_t *ptr = pkt.data;
830                         int data_size;
831
832                         // We only deal with video from the selected video_index
833                         while ( ptr != NULL && ret >= 0 && pkt.stream_index == index && len > 0 )
834                         {
835                                 // Decode the audio
836                                 ret = avcodec_decode_audio( codec_context, temp, &data_size, ptr, len );
837
838                                 if ( ret < 0 )
839                                 {
840                                         ret = 0;
841                                         break;
842                                 }
843
844                                 len -= ret;
845                                 ptr += ret;
846
847                                 if ( data_size > 0 )
848                                 {
849                                         int size_out = audio_resample( resample, &audio_buffer[ audio_used * *channels ], temp, data_size / ( codec_context->channels * sizeof( int16_t ) ) );
850
851                                         audio_used += size_out;
852
853                                         // Handle ignore
854                                         while ( ignore && audio_used > *samples )
855                                         {
856                                                 ignore --;
857                                                 audio_used -= *samples;
858                                                 memmove( audio_buffer, &audio_buffer[ *samples * *channels ], audio_used * sizeof( int16_t ) );
859                                         }
860                                 }
861
862                                 // If we're behind, ignore this packet
863                                 float current_pts = (float)pkt.pts / 1000000.0;
864                                 double discrepancy = mlt_properties_get_double( properties, "discrepancy" );
865                                 if ( current_pts != 0 && real_timecode != 0 )
866                                 {
867                                         if ( discrepancy != 1 )
868                                                 discrepancy = ( discrepancy + ( real_timecode / current_pts ) ) / 2;
869                                         else
870                                                 discrepancy = real_timecode / current_pts;
871                                         if ( discrepancy > 0.9 && discrepancy < 1.1 )
872                                                 discrepancy = 1.0;
873                                         else
874                                                 discrepancy = floor( discrepancy + 0.5 );
875
876                                         if ( discrepancy == 0 )
877                                                 discrepancy = 1.0;
878
879                                         mlt_properties_set_double( properties, "discrepancy", discrepancy );
880                                 }
881
882                                 if ( !ignore && discrepancy * current_pts <= ( real_timecode - 0.02 ) )
883                                         ignore = 1;
884                         }
885
886                         // We're finished with this packet regardless
887                         av_free_packet( &pkt );
888                 }
889
890                 *buffer = mlt_pool_alloc( *samples * *channels * sizeof( int16_t ) );
891                 mlt_properties_set_data( frame_properties, "audio", *buffer, 0, ( mlt_destructor )mlt_pool_release, NULL );
892
893                 // Now handle the audio if we have enough
894                 if ( audio_used >= *samples )
895                 {
896                         memcpy( *buffer, audio_buffer, *samples * *channels * sizeof( int16_t ) );
897                         audio_used -= *samples;
898                         memmove( audio_buffer, &audio_buffer[ *samples * *channels ], audio_used * *channels * sizeof( int16_t ) );
899                 }
900                 else
901                 {
902                         memset( *buffer, 0, *samples * *channels * sizeof( int16_t ) );
903                 }
904                 
905                 // Store the number of audio samples still available
906                 mlt_properties_set_int( properties, "audio_used", audio_used );
907
908                 // Release the temporary audio
909                 mlt_pool_release( temp );
910         }
911         else
912         {
913                 // Get silence and don't touch the context
914                 frame->get_audio = NULL;
915                 mlt_frame_get_audio( frame, buffer, format, frequency, channels, samples );
916         }
917
918         // Regardless of speed, we expect to get the next frame (cos we ain't too bright)
919         mlt_properties_set_position( properties, "audio_expected", position + 1 );
920
921         // Unlock the mutex now
922         pthread_mutex_unlock( &avformat_mutex );
923
924         return 0;
925 }
926
927 /** Set up audio handling.
928 */
929
930 static void producer_set_up_audio( mlt_producer this, mlt_frame frame )
931 {
932         // Get the properties
933         mlt_properties properties = mlt_producer_properties( this );
934
935         // Fetch the audio_context
936         AVFormatContext *context = mlt_properties_get_data( properties, "audio_context", NULL );
937
938         // Get the audio_index
939         int index = mlt_properties_get_int( properties, "audio_index" );
940
941         // Lock the mutex now
942         pthread_mutex_lock( &avformat_mutex );
943
944         // Deal with audio context
945         if ( context != NULL && index != -1 )
946         {
947                 // Get the frame properties
948                 mlt_properties frame_properties = mlt_frame_properties( frame );
949
950                 // Get the audio stream
951                 AVStream *stream = context->streams[ index ];
952
953                 // Get codec context
954                 AVCodecContext *codec_context = &stream->codec;
955
956                 // Get the codec
957                 AVCodec *codec = mlt_properties_get_data( properties, "audio_codec", NULL );
958
959                 // Initialise the codec if necessary
960                 if ( codec == NULL )
961                 {
962                         // Find the codec
963                         codec = avcodec_find_decoder( codec_context->codec_id );
964
965                         // If we don't have a codec and we can't initialise it, we can't do much more...
966                         if ( codec != NULL && avcodec_open( codec_context, codec ) >= 0 )
967                         {
968                                 // Now store the codec with its destructor
969                                 mlt_properties_set_data( properties, "audio_codec", codec_context, 0, producer_codec_close, NULL );
970
971                         }
972                         else
973                         {
974                                 // Remember that we can't use this later
975                                 mlt_properties_set_int( properties, "audio_index", -1 );
976                         }
977                 }
978
979                 // No codec, no show...
980                 if ( codec != NULL )
981                 {
982                         frame->get_audio = producer_get_audio;
983                         mlt_properties_set_data( frame_properties, "avformat_producer", this, 0, NULL, NULL );
984                 }
985         }
986
987         // Unlock the mutex now
988         pthread_mutex_unlock( &avformat_mutex );
989 }
990
991 /** Our get frame implementation.
992 */
993
994 static int producer_get_frame( mlt_producer this, mlt_frame_ptr frame, int index )
995 {
996         // Create an empty frame
997         *frame = mlt_frame_init( );
998
999         // Update timecode on the frame we're creating
1000         mlt_frame_set_position( *frame, mlt_producer_position( this ) );
1001
1002         // Set the position of this producer
1003         mlt_properties_set_position( mlt_frame_properties( *frame ), "avformat_position", mlt_producer_get_in( this ) + mlt_producer_position( this ) );
1004
1005         // Set up the video
1006         producer_set_up_video( this, *frame );
1007
1008         // Set up the audio
1009         producer_set_up_audio( this, *frame );
1010
1011         // Set the aspect_ratio
1012         mlt_properties_set_double( mlt_frame_properties( *frame ), "aspect_ratio", mlt_properties_get_double( mlt_producer_properties( this ), "aspect_ratio" ) );
1013
1014         // Calculate the next timecode
1015         mlt_producer_prepare_next( this );
1016
1017         return 0;
1018 }