2 * producer_avformat.c -- avformat producer
3 * Copyright (C) 2003-2004 Ushodaya Enterprises Limited
4 * Author: Charles Yates <charles.yates@pandora.be>
5 * Much code borrowed from ffmpeg.c: Copyright (c) 2000-2003 Fabrice Bellard
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with this library; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 #include <framework/mlt_producer.h>
24 #include <framework/mlt_frame.h>
26 // ffmpeg Header files
32 // System header files
38 void avformat_lock( );
39 void avformat_unlock( );
41 // Forward references.
42 static int producer_open( mlt_producer this, mlt_profile profile, char *file );
43 static int producer_get_frame( mlt_producer this, mlt_frame_ptr frame, int index );
45 /** Constructor for libavformat.
48 mlt_producer producer_avformat_init( mlt_profile profile, char *file )
50 mlt_producer this = NULL;
52 // Check that we have a non-NULL argument
55 // Construct the producer
56 this = calloc( 1, sizeof( struct mlt_producer_s ) );
59 if ( mlt_producer_init( this, NULL ) == 0 )
62 mlt_properties properties = MLT_PRODUCER_PROPERTIES( this );
64 // Set the resource property (required for all producers)
65 mlt_properties_set( properties, "resource", file );
67 // Register our get_frame implementation
68 this->get_frame = producer_get_frame;
71 if ( producer_open( this, profile, file ) != 0 )
74 mlt_producer_close( this );
83 /** Find the default streams.
86 static void find_default_streams( AVFormatContext *context, int *audio_index, int *video_index )
90 // Allow for multiple audio and video streams in the file and select first of each (if available)
91 for( i = 0; i < context->nb_streams; i++ )
93 // Get the codec context
94 AVCodecContext *codec_context = context->streams[ i ]->codec;
96 if ( avcodec_find_decoder( codec_context->codec_id ) == NULL )
99 // Determine the type and obtain the first index of each type
100 switch( codec_context->codec_type )
102 case CODEC_TYPE_VIDEO:
103 if ( *video_index < 0 )
106 case CODEC_TYPE_AUDIO:
107 if ( *audio_index < 0 )
116 /** Producer file destructor.
119 static void producer_file_close( void *context )
121 if ( context != NULL )
123 // Lock the mutex now
127 av_close_input_file( context );
129 // Unlock the mutex now
134 /** Producer file destructor.
137 static void producer_codec_close( void *codec )
141 // Lock the mutex now
145 avcodec_close( codec );
147 // Unlock the mutex now
155 static int producer_open( mlt_producer this, mlt_profile profile, char *file )
157 // Return an error code (0 == no error)
160 // Context for avformat
161 AVFormatContext *context = NULL;
163 // Get the properties
164 mlt_properties properties = MLT_PRODUCER_PROPERTIES( this );
166 // We will treat everything with the producer fps
167 double fps = mlt_profile_fps( profile );
169 // Lock the mutex now
172 // If "MRL", then create AVInputFormat
173 AVInputFormat *format = NULL;
174 AVFormatParameters *params = NULL;
175 char *standard = NULL;
176 char *mrl = strchr( file, ':' );
178 // AV option (0 = both, 1 = video, 2 = audio)
181 // Setting lowest log level
182 av_log_set_level( -1 );
184 // Only if there is not a protocol specification that avformat can handle
185 if ( mrl && !url_exist( file ) )
187 // 'file' becomes format abbreviation
191 format = av_find_input_format( file );
193 // Eat the format designator
199 params = calloc( sizeof( AVFormatParameters ), 1 );
201 // These are required by video4linux (defaults)
203 params->height = 480;
204 params->time_base= (AVRational){1,25};
205 // params->device = file;
206 params->channels = 2;
207 params->sample_rate = 48000;
210 // XXX: this does not work anymore since avdevice
211 // TODO: make producer_avddevice?
213 mrl = strchr( file, '?' );
217 char *name = strdup( ++mrl );
218 char *value = strchr( name, ':' );
223 char *t = strchr( value, '&' );
226 if ( !strcmp( name, "frame_rate" ) )
227 params->time_base.den = atoi( value );
228 else if ( !strcmp( name, "frame_rate_base" ) )
229 params->time_base.num = atoi( value );
230 else if ( !strcmp( name, "sample_rate" ) )
231 params->sample_rate = atoi( value );
232 else if ( !strcmp( name, "channels" ) )
233 params->channels = atoi( value );
234 else if ( !strcmp( name, "width" ) )
235 params->width = atoi( value );
236 else if ( !strcmp( name, "height" ) )
237 params->height = atoi( value );
238 else if ( !strcmp( name, "standard" ) )
240 standard = strdup( value );
241 params->standard = standard;
243 else if ( !strcmp( name, "av" ) )
247 mrl = strchr( mrl, '&' );
251 // Now attempt to open the file
252 error = av_open_input_file( &context, file, format, 0, params ) < 0;
254 // Cleanup AVFormatParameters
258 // If successful, then try to get additional info
261 // Get the stream info
262 error = av_find_stream_info( context ) < 0;
264 // Continue if no error
267 // We will default to the first audio and video streams found
268 int audio_index = -1;
269 int video_index = -1;
272 // Now set properties where we can (use default unknowns if required)
273 if ( context->duration != AV_NOPTS_VALUE )
275 // This isn't going to be accurate for all formats
276 mlt_position frames = ( mlt_position )( ( ( double )context->duration / ( double )AV_TIME_BASE ) * fps + 0.5 );
277 mlt_properties_set_position( properties, "out", frames - 1 );
278 mlt_properties_set_position( properties, "length", frames );
281 // Find default audio and video streams
282 find_default_streams( context, &audio_index, &video_index );
284 if ( context->start_time != AV_NOPTS_VALUE )
285 mlt_properties_set_double( properties, "_start_time", context->start_time );
287 // Check if we're seekable (something funny about mpeg here :-/)
288 if ( strcmp( file, "pipe:" ) && strncmp( file, "http://", 6 ) )
290 mlt_properties_set_int( properties, "seekable", av_seek_frame( context, -1, mlt_properties_get_double( properties, "_start_time" ), AVSEEK_FLAG_BACKWARD ) >= 0 );
291 mlt_properties_set_data( properties, "dummy_context", context, 0, producer_file_close, NULL );
292 av_open_input_file( &context, file, NULL, 0, NULL );
293 av_find_stream_info( context );
298 // Store selected audio and video indexes on properties
299 mlt_properties_set_int( properties, "audio_index", audio_index );
300 mlt_properties_set_int( properties, "video_index", video_index );
301 mlt_properties_set_int( properties, "_last_position", -1 );
303 // Fetch the width, height and aspect ratio
304 if ( video_index != -1 )
306 AVCodecContext *codec_context = context->streams[ video_index ]->codec;
307 mlt_properties_set_int( properties, "width", codec_context->width );
308 mlt_properties_set_int( properties, "height", codec_context->height );
309 mlt_properties_set_double( properties, "aspect_ratio", av_q2d( codec_context->sample_aspect_ratio ) );
313 if (context->title != NULL)
314 mlt_properties_set(properties, "meta.attr.title.markup", context->title );
315 if (context->author != NULL)
316 mlt_properties_set(properties, "meta.attr.author.markup", context->author );
317 if (context->copyright != NULL)
318 mlt_properties_set(properties, "meta.attr.copyright.markup", context->copyright );
319 if (context->comment != NULL)
320 mlt_properties_set(properties, "meta.attr.comment.markup", context->comment );
321 if (context->album != NULL)
322 mlt_properties_set(properties, "meta.attr.album.markup", context->album );
323 if (context->year != 0)
324 mlt_properties_set_int(properties, "meta.attr.year.markup", context->year );
325 if (context->track != 0)
326 mlt_properties_set_int(properties, "meta.attr.track.markup", context->track );
328 // We're going to cheat here - for a/v files, we will have two contexts (reasoning will be clear later)
329 if ( av == 0 && !av_bypass && audio_index != -1 && video_index != -1 )
331 // We'll use the open one as our video_context
332 mlt_properties_set_data( properties, "video_context", context, 0, producer_file_close, NULL );
334 // And open again for our audio context
335 av_open_input_file( &context, file, NULL, 0, NULL );
336 av_find_stream_info( context );
339 mlt_properties_set_data( properties, "audio_context", context, 0, producer_file_close, NULL );
341 else if ( av != 2 && video_index != -1 )
343 // We only have a video context
344 mlt_properties_set_data( properties, "video_context", context, 0, producer_file_close, NULL );
346 else if ( audio_index != -1 )
348 // We only have an audio context
349 mlt_properties_set_data( properties, "audio_context", context, 0, producer_file_close, NULL );
353 // Something has gone wrong
357 mlt_properties_set_int( properties, "av_bypass", av_bypass );
361 // Unlock the mutex now
367 /** Convert a frame position to a time code.
370 static double producer_time_of_frame( mlt_producer this, mlt_position position )
372 return ( double )position / mlt_producer_get_fps( this );
375 static inline void convert_image( AVFrame *frame, uint8_t *buffer, int pix_fmt, mlt_image_format format, int width, int height )
378 if ( format == mlt_image_yuv420p )
380 struct SwsContext *context = sws_getContext( width, height, pix_fmt,
381 width, height, PIX_FMT_YUV420P, SWS_FAST_BILINEAR, NULL, NULL, NULL);
383 output.data[0] = buffer;
384 output.data[1] = buffer + width * height;
385 output.data[2] = buffer + ( 3 * width * height ) / 2;
386 output.linesize[0] = width;
387 output.linesize[1] = width >> 1;
388 output.linesize[2] = width >> 1;
389 sws_scale( context, frame->data, frame->linesize, 0, height,
390 output.data, output.linesize);
391 sws_freeContext( context );
393 else if ( format == mlt_image_rgb24 )
395 struct SwsContext *context = sws_getContext( width, height, pix_fmt,
396 width, height, PIX_FMT_RGB24, SWS_FAST_BILINEAR, NULL, NULL, NULL);
398 avpicture_fill( &output, buffer, PIX_FMT_RGB24, width, height );
399 sws_scale( context, frame->data, frame->linesize, 0, height,
400 output.data, output.linesize);
401 sws_freeContext( context );
405 struct SwsContext *context = sws_getContext( width, height, pix_fmt,
406 width, height, PIX_FMT_YUYV422, SWS_FAST_BILINEAR, NULL, NULL, NULL);
408 avpicture_fill( &output, buffer, PIX_FMT_YUYV422, width, height );
409 sws_scale( context, frame->data, frame->linesize, 0, height,
410 output.data, output.linesize);
411 sws_freeContext( context );
414 if ( format == mlt_image_yuv420p )
417 pict.data[0] = buffer;
418 pict.data[1] = buffer + width * height;
419 pict.data[2] = buffer + ( 3 * width * height ) / 2;
420 pict.linesize[0] = width;
421 pict.linesize[1] = width >> 1;
422 pict.linesize[2] = width >> 1;
423 img_convert( &pict, PIX_FMT_YUV420P, (AVPicture *)frame, pix_fmt, width, height );
425 else if ( format == mlt_image_rgb24 )
428 avpicture_fill( &output, buffer, PIX_FMT_RGB24, width, height );
429 img_convert( &output, PIX_FMT_RGB24, (AVPicture *)frame, pix_fmt, width, height );
434 avpicture_fill( &output, buffer, PIX_FMT_YUV422, width, height );
435 img_convert( &output, PIX_FMT_YUV422, (AVPicture *)frame, pix_fmt, width, height );
440 /** Get an image from a frame.
443 static int producer_get_image( mlt_frame frame, uint8_t **buffer, mlt_image_format *format, int *width, int *height, int writable )
445 // Get the properties from the frame
446 mlt_properties frame_properties = MLT_FRAME_PROPERTIES( frame );
448 // Obtain the frame number of this frame
449 mlt_position position = mlt_properties_get_position( frame_properties, "avformat_position" );
452 mlt_producer this = mlt_properties_get_data( frame_properties, "avformat_producer", NULL );
454 // Get the producer properties
455 mlt_properties properties = MLT_PRODUCER_PROPERTIES( this );
457 // Fetch the video_context
458 AVFormatContext *context = mlt_properties_get_data( properties, "video_context", NULL );
460 // Get the video_index
461 int index = mlt_properties_get_int( properties, "video_index" );
463 // Obtain the expected frame numer
464 mlt_position expected = mlt_properties_get_position( properties, "_video_expected" );
466 // Get the video stream
467 AVStream *stream = context->streams[ index ];
470 AVCodecContext *codec_context = stream->codec;
475 // Get the conversion frame
476 AVFrame *av_frame = mlt_properties_get_data( properties, "av_frame", NULL );
478 // Special case pause handling flag
481 // Special case ffwd handling
484 // We may want to use the source fps if available
485 double source_fps = mlt_properties_get_double( properties, "source_fps" );
486 double fps = mlt_producer_get_fps( this );
488 // This is the physical frame position in the source
489 int req_position = ( int )( position / fps * source_fps + 0.5 );
491 // Get the seekable status
492 int seekable = mlt_properties_get_int( properties, "seekable" );
494 // Generate the size in bytes
497 // Hopefully provide better support for streams...
498 int av_bypass = mlt_properties_get_int( properties, "av_bypass" );
500 // Determines if we have to decode all frames in a sequence
503 // Set the result arguments that we know here (only *buffer is now required)
504 *width = codec_context->width;
505 *height = codec_context->height;
509 case mlt_image_yuv420p:
510 size = *width * 3 * ( *height + 1 ) / 2;
512 case mlt_image_rgb24:
513 size = *width * ( *height + 1 ) * 3;
516 *format = mlt_image_yuv422;
517 size = *width * ( *height + 1 ) * 2;
521 // Set this on the frame properties
522 mlt_properties_set_int( frame_properties, "width", *width );
523 mlt_properties_set_int( frame_properties, "height", *height );
525 // Construct the output image
526 *buffer = mlt_pool_alloc( size );
528 // Temporary hack to improve intra frame only
529 must_decode = strcmp( codec_context->codec->name, "mjpeg" ) &&
530 strcmp( codec_context->codec->name, "rawvideo" ) &&
531 strcmp( codec_context->codec->name, "dvvideo" );
534 if ( position != expected )
536 if ( av_frame != NULL && position + 1 == expected )
538 // We're paused - use last image
541 else if ( !seekable && position > expected && ( position - expected ) < 250 )
543 // Fast forward - seeking is inefficient for small distances - just ignore following frames
544 ignore = ( int )( ( position - expected ) / fps * source_fps );
546 else if ( seekable && ( position < expected || position - expected >= 12 ) )
548 // Calculate the timestamp for the requested frame
549 int64_t timestamp = ( int64_t )( ( double )req_position / source_fps * AV_TIME_BASE + 0.5 );
550 if ( ( uint64_t )context->start_time != AV_NOPTS_VALUE )
551 timestamp += context->start_time;
553 timestamp -= AV_TIME_BASE;
557 // Set to the timestamp
558 av_seek_frame( context, -1, timestamp, AVSEEK_FLAG_BACKWARD );
560 // Remove the cached info relating to the previous position
561 mlt_properties_set_int( properties, "_current_position", -1 );
562 mlt_properties_set_int( properties, "_last_position", -1 );
563 mlt_properties_set_data( properties, "av_frame", NULL, 0, NULL, NULL );
568 // Duplicate the last image if necessary (see comment on rawvideo below)
569 int current_position = mlt_properties_get_int( properties, "_current_position" );
570 int got_picture = mlt_properties_get_int( properties, "_got_picture" );
571 if ( av_frame != NULL && got_picture && ( paused || current_position >= req_position ) && av_bypass == 0 )
574 convert_image( av_frame, *buffer, codec_context->pix_fmt, *format, *width, *height );
576 // Set this on the frame properties
577 mlt_properties_set_data( frame_properties, "image", *buffer, size, ( mlt_destructor )mlt_pool_release, NULL );
582 int int_position = 0;
585 av_init_packet( &pkt );
587 // Construct an AVFrame for YUV422 conversion
588 if ( av_frame == NULL )
590 av_frame = avcodec_alloc_frame( );
591 mlt_properties_set_data( properties, "av_frame", av_frame, 0, av_free, NULL );
594 while( ret >= 0 && !got_picture )
597 ret = av_read_frame( context, &pkt );
599 // We only deal with video from the selected video_index
600 if ( ret >= 0 && pkt.stream_index == index && pkt.size > 0 )
602 // Determine time code of the packet
603 int_position = ( int )( av_q2d( stream->time_base ) * pkt.dts * source_fps + 0.5 );
604 if ( context->start_time != AV_NOPTS_VALUE )
605 int_position -= ( int )( context->start_time * source_fps / AV_TIME_BASE + 0.5 );
606 int last_position = mlt_properties_get_int( properties, "_last_position" );
607 if ( int_position == last_position )
608 int_position = last_position + 1;
609 mlt_properties_set_int( properties, "_last_position", int_position );
612 if ( must_decode || int_position >= req_position )
613 ret = avcodec_decode_video( codec_context, av_frame, &got_picture, pkt.data, pkt.size );
618 if ( int_position < req_position )
623 else if ( int_position >= req_position )
627 else if ( ignore -- )
632 av_free_packet( &pkt );
636 av_free_packet( &pkt );
639 // Now handle the picture if we have one
642 mlt_properties_set_int( frame_properties, "progressive", !av_frame->interlaced_frame );
643 mlt_properties_set_int( frame_properties, "top_field_first", av_frame->top_field_first );
644 mlt_properties_set_int( properties, "top_field_first", av_frame->top_field_first );
645 convert_image( av_frame, *buffer, codec_context->pix_fmt, *format, *width, *height );
646 mlt_properties_set_data( frame_properties, "image", *buffer, size, (mlt_destructor)mlt_pool_release, NULL );
647 mlt_properties_set_int( properties, "_current_position", int_position );
648 mlt_properties_set_int( properties, "_got_picture", 1 );
653 // Very untidy - for rawvideo, the packet contains the frame, hence the free packet
654 // above will break the pause behaviour - so we wipe the frame now
655 if ( !strcmp( codec_context->codec->name, "rawvideo" ) )
656 mlt_properties_set_data( properties, "av_frame", NULL, 0, NULL, NULL );
658 // Set the field order property for this frame
659 mlt_properties_set_int( frame_properties, "top_field_first", mlt_properties_get_int( properties, "top_field_first" ) );
661 // Regardless of speed, we expect to get the next frame (cos we ain't too bright)
662 mlt_properties_set_position( properties, "_video_expected", position + 1 );
667 /** Set up video handling.
670 static void producer_set_up_video( mlt_producer this, mlt_frame frame )
672 // Get the properties
673 mlt_properties properties = MLT_PRODUCER_PROPERTIES( this );
675 // Fetch the video_context
676 AVFormatContext *context = mlt_properties_get_data( properties, "video_context", NULL );
678 // Get the video_index
679 int index = mlt_properties_get_int( properties, "video_index" );
681 // Get the frame properties
682 mlt_properties frame_properties = MLT_FRAME_PROPERTIES( frame );
684 if ( context != NULL && index != -1 )
686 // Get the video stream
687 AVStream *stream = context->streams[ index ];
690 AVCodecContext *codec_context = stream->codec;
693 AVCodec *codec = mlt_properties_get_data( properties, "video_codec", NULL );
695 // Initialise the codec if necessary
698 // Initialise multi-threading
699 int thread_count = mlt_properties_get_int( properties, "threads" );
700 if ( thread_count == 0 && getenv( "MLT_AVFORMAT_THREADS" ) )
701 thread_count = atoi( getenv( "MLT_AVFORMAT_THREADS" ) );
702 if ( thread_count > 1 )
704 avcodec_thread_init( codec_context, thread_count );
705 codec_context->thread_count = thread_count;
709 codec = avcodec_find_decoder( codec_context->codec_id );
711 // If we don't have a codec and we can't initialise it, we can't do much more...
712 if ( codec != NULL && avcodec_open( codec_context, codec ) >= 0 )
714 // Now store the codec with its destructor
715 mlt_properties_set_data( properties, "video_codec", codec_context, 0, producer_codec_close, NULL );
719 // Remember that we can't use this later
720 mlt_properties_set_int( properties, "video_index", -1 );
724 // No codec, no show...
727 double source_fps = 0;
728 int norm_aspect_ratio = mlt_properties_get_int( properties, "norm_aspect_ratio" );
729 double force_aspect_ratio = mlt_properties_get_double( properties, "force_aspect_ratio" );
732 // XXX: We won't know the real aspect ratio until an image is decoded
733 // but we do need it now (to satisfy filter_resize) - take a guess based
735 if ( force_aspect_ratio > 0.0 )
737 aspect_ratio = force_aspect_ratio;
739 else if ( !norm_aspect_ratio && codec_context->sample_aspect_ratio.num > 0 )
741 aspect_ratio = av_q2d( codec_context->sample_aspect_ratio );
745 int is_pal = mlt_producer_get_fps( this ) == 25.0;
746 aspect_ratio = is_pal ? 59.0/54.0 : 10.0/11.0;
750 source_fps = ( double )codec_context->time_base.den / ( codec_context->time_base.num == 0 ? 1 : codec_context->time_base.num );
752 // We'll use fps if it's available
753 if ( source_fps > 0 )
754 mlt_properties_set_double( properties, "source_fps", source_fps );
756 mlt_properties_set_double( properties, "source_fps", mlt_producer_get_fps( this ) );
757 mlt_properties_set_double( properties, "aspect_ratio", aspect_ratio );
759 // Set the width and height
760 mlt_properties_set_int( frame_properties, "width", codec_context->width );
761 mlt_properties_set_int( frame_properties, "height", codec_context->height );
762 mlt_properties_set_double( frame_properties, "aspect_ratio", aspect_ratio );
764 mlt_frame_push_get_image( frame, producer_get_image );
765 mlt_properties_set_data( frame_properties, "avformat_producer", this, 0, NULL, NULL );
769 mlt_properties_set_int( frame_properties, "test_image", 1 );
774 mlt_properties_set_int( frame_properties, "test_image", 1 );
778 /** Get the audio from a frame.
781 static int producer_get_audio( mlt_frame frame, int16_t **buffer, mlt_audio_format *format, int *frequency, int *channels, int *samples )
783 // Get the properties from the frame
784 mlt_properties frame_properties = MLT_FRAME_PROPERTIES( frame );
786 // Obtain the frame number of this frame
787 mlt_position position = mlt_properties_get_position( frame_properties, "avformat_position" );
790 mlt_producer this = mlt_properties_get_data( frame_properties, "avformat_producer", NULL );
792 // Get the producer properties
793 mlt_properties properties = MLT_PRODUCER_PROPERTIES( this );
795 // Fetch the audio_context
796 AVFormatContext *context = mlt_properties_get_data( properties, "audio_context", NULL );
798 // Get the audio_index
799 int index = mlt_properties_get_int( properties, "audio_index" );
801 // Get the seekable status
802 int seekable = mlt_properties_get_int( properties, "seekable" );
804 // Obtain the expected frame numer
805 mlt_position expected = mlt_properties_get_position( properties, "_audio_expected" );
807 // Obtain the resample context if it exists (not always needed)
808 ReSampleContext *resample = mlt_properties_get_data( properties, "audio_resample", NULL );
810 // Obtain the audio buffer
811 int16_t *audio_buffer = mlt_properties_get_data( properties, "audio_buffer", NULL );
813 // Get amount of audio used
814 int audio_used = mlt_properties_get_int( properties, "_audio_used" );
816 // Calculate the real time code
817 double real_timecode = producer_time_of_frame( this, position );
819 // Get the audio stream
820 AVStream *stream = context->streams[ index ];
823 AVCodecContext *codec_context = stream->codec;
828 // Number of frames to ignore (for ffwd)
831 // Flag for paused (silence)
834 // Check for resample and create if necessary
835 if ( resample == NULL && codec_context->channels <= 2 )
837 // Create the resampler
838 resample = audio_resample_init( *channels, codec_context->channels, *frequency, codec_context->sample_rate );
840 // And store it on properties
841 mlt_properties_set_data( properties, "audio_resample", resample, 0, ( mlt_destructor )audio_resample_close, NULL );
843 else if ( resample == NULL )
845 *channels = codec_context->channels;
846 *frequency = codec_context->sample_rate;
849 // Check for audio buffer and create if necessary
850 if ( audio_buffer == NULL )
852 // Allocate the audio buffer
853 audio_buffer = mlt_pool_alloc( AVCODEC_MAX_AUDIO_FRAME_SIZE * sizeof( int16_t ) );
855 // And store it on properties for reuse
856 mlt_properties_set_data( properties, "audio_buffer", audio_buffer, 0, ( mlt_destructor )mlt_pool_release, NULL );
860 if ( position != expected )
862 if ( position + 1 == expected )
864 // We're paused - silence required
867 else if ( !seekable && position > expected && ( position - expected ) < 250 )
869 // Fast forward - seeking is inefficient for small distances - just ignore following frames
870 ignore = position - expected;
872 else if ( position < expected || position - expected >= 12 )
874 // Set to the real timecode
875 if ( av_seek_frame( context, -1, mlt_properties_get_double( properties, "_start_time" ) + real_timecode * 1000000.0, AVSEEK_FLAG_BACKWARD ) != 0 )
878 // Clear the usage in the audio buffer
883 // Get the audio if required
888 int16_t *temp = av_malloc( sizeof( int16_t ) * AVCODEC_MAX_AUDIO_FRAME_SIZE );
890 av_init_packet( &pkt );
892 while( ret >= 0 && !got_audio )
894 // Check if the buffer already contains the samples required
895 if ( audio_used >= *samples && ignore == 0 )
902 ret = av_read_frame( context, &pkt );
905 uint8_t *ptr = pkt.data;
907 // We only deal with audio from the selected audio_index
908 while ( ptr != NULL && ret >= 0 && pkt.stream_index == index && len > 0 )
910 int data_size = sizeof( int16_t ) * AVCODEC_MAX_AUDIO_FRAME_SIZE;
913 #if (LIBAVCODEC_VERSION_INT >= ((51<<16)+(29<<8)+0))
914 ret = avcodec_decode_audio2( codec_context, temp, &data_size, ptr, len );
916 ret = avcodec_decode_audio( codec_context, temp, &data_size, ptr, len );
929 if ( resample != NULL )
931 audio_used += audio_resample( resample, &audio_buffer[ audio_used * *channels ], temp, data_size / ( codec_context->channels * sizeof( int16_t ) ) );
935 memcpy( &audio_buffer[ audio_used * *channels ], temp, data_size );
936 audio_used += data_size / ( codec_context->channels * sizeof( int16_t ) );
940 while ( ignore && audio_used > *samples )
943 audio_used -= *samples;
944 memmove( audio_buffer, &audio_buffer[ *samples * *channels ], audio_used * sizeof( int16_t ) );
948 // If we're behind, ignore this packet
949 float current_pts = av_q2d( stream->time_base ) * pkt.pts;
950 if ( seekable && ( !ignore && current_pts <= ( real_timecode - 0.02 ) ) )
954 // We're finished with this packet regardless
955 av_free_packet( &pkt );
958 *buffer = mlt_pool_alloc( *samples * *channels * sizeof( int16_t ) );
959 mlt_properties_set_data( frame_properties, "audio", *buffer, 0, ( mlt_destructor )mlt_pool_release, NULL );
961 // Now handle the audio if we have enough
962 if ( audio_used >= *samples )
964 memcpy( *buffer, audio_buffer, *samples * *channels * sizeof( int16_t ) );
965 audio_used -= *samples;
966 memmove( audio_buffer, &audio_buffer[ *samples * *channels ], audio_used * *channels * sizeof( int16_t ) );
970 memset( *buffer, 0, *samples * *channels * sizeof( int16_t ) );
973 // Store the number of audio samples still available
974 mlt_properties_set_int( properties, "_audio_used", audio_used );
976 // Release the temporary audio
981 // Get silence and don't touch the context
982 mlt_frame_get_audio( frame, buffer, format, frequency, channels, samples );
985 // Regardless of speed (other than paused), we expect to get the next frame
987 mlt_properties_set_position( properties, "_audio_expected", position + 1 );
992 /** Set up audio handling.
995 static void producer_set_up_audio( mlt_producer this, mlt_frame frame )
997 // Get the properties
998 mlt_properties properties = MLT_PRODUCER_PROPERTIES( this );
1000 // Fetch the audio_context
1001 AVFormatContext *context = mlt_properties_get_data( properties, "audio_context", NULL );
1003 // Get the audio_index
1004 int index = mlt_properties_get_int( properties, "audio_index" );
1006 // Deal with audio context
1007 if ( context != NULL && index != -1 )
1009 // Get the frame properties
1010 mlt_properties frame_properties = MLT_FRAME_PROPERTIES( frame );
1012 // Get the audio stream
1013 AVStream *stream = context->streams[ index ];
1015 // Get codec context
1016 AVCodecContext *codec_context = stream->codec;
1019 AVCodec *codec = mlt_properties_get_data( properties, "audio_codec", NULL );
1021 // Initialise the codec if necessary
1022 if ( codec == NULL )
1024 // Initialise multi-threading
1025 int thread_count = mlt_properties_get_int( properties, "threads" );
1026 if ( thread_count == 0 && getenv( "MLT_AVFORMAT_THREADS" ) )
1027 thread_count = atoi( getenv( "MLT_AVFORMAT_THREADS" ) );
1028 if ( thread_count > 1 )
1030 avcodec_thread_init( codec_context, thread_count );
1031 codec_context->thread_count = thread_count;
1035 codec = avcodec_find_decoder( codec_context->codec_id );
1037 // If we don't have a codec and we can't initialise it, we can't do much more...
1038 if ( codec != NULL && avcodec_open( codec_context, codec ) >= 0 )
1040 // Now store the codec with its destructor
1041 mlt_properties_set_data( properties, "audio_codec", codec_context, 0, producer_codec_close, NULL );
1046 // Remember that we can't use this later
1047 mlt_properties_set_int( properties, "audio_index", -1 );
1051 // No codec, no show...
1052 if ( codec != NULL )
1054 mlt_frame_push_audio( frame, producer_get_audio );
1055 mlt_properties_set_data( frame_properties, "avformat_producer", this, 0, NULL, NULL );
1056 mlt_properties_set_int( frame_properties, "frequency", codec_context->sample_rate );
1057 mlt_properties_set_int( frame_properties, "channels", codec_context->channels );
1062 /** Our get frame implementation.
1065 static int producer_get_frame( mlt_producer this, mlt_frame_ptr frame, int index )
1067 // Create an empty frame
1068 *frame = mlt_frame_init( MLT_PRODUCER_SERVICE( this ) );
1070 // Update timecode on the frame we're creating
1071 mlt_frame_set_position( *frame, mlt_producer_position( this ) );
1073 // Set the position of this producer
1074 mlt_properties_set_position( MLT_FRAME_PROPERTIES( *frame ), "avformat_position", mlt_producer_frame( this ) );
1077 producer_set_up_video( this, *frame );
1080 producer_set_up_audio( this, *frame );
1082 // Set the aspect_ratio
1083 mlt_properties_set_double( MLT_FRAME_PROPERTIES( *frame ), "aspect_ratio", mlt_properties_get_double( MLT_PRODUCER_PROPERTIES( this ), "aspect_ratio" ) );
1085 // Calculate the next timecode
1086 mlt_producer_prepare_next( this );