git.sesse.net Git - mlt/blob - src/modules/decklink/producer_decklink.cpp

   1 /*
   2  * producer_decklink.c -- input from Blackmagic Design DeckLink
   3  * Copyright (C) 2011 Dan Dennedy <dan@dennedy.org>
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2.1 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with consumer library; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  */
  19
  20 #include <framework/mlt.h>
  21 #include <stdlib.h>
  22 #include <pthread.h>
  23 #include <string.h>
  24 #include <unistd.h>
  25 #include <limits.h>
  26 #include <sys/time.h>
  27 #ifdef WIN32
  28 #include <objbase.h>
  29 #include "DeckLinkAPI_h.h"
  30 #else
  31 #include "DeckLinkAPI.h"
  32 #endif
  33
  34 class DeckLinkProducer
  35         : public IDeckLinkInputCallback
  36 {
  37 private:
  38         mlt_producer_s   m_producer;
  39         IDeckLink*       m_decklink;
  40         IDeckLinkInput*  m_decklinkInput;
  41         mlt_deque        m_queue;
  42         pthread_mutex_t  m_mutex;
  43         pthread_cond_t   m_condition;
  44         bool             m_started;
  45         int              m_dropped;
  46         bool             m_isBuffering;
  47         int              m_topFieldFirst;
  48         int              m_colorspace;
  49         int              m_vancLines;
  50
  51         BMDDisplayMode getDisplayMode( mlt_profile profile, int vancLines )
  52         {
  53                 IDeckLinkDisplayModeIterator* iter;
  54                 IDeckLinkDisplayMode* mode;
  55                 BMDDisplayMode result = (BMDDisplayMode) bmdDisplayModeNotSupported;
  56
  57                 if ( m_decklinkInput->GetDisplayModeIterator( &iter ) == S_OK )
  58                 {
  59                         while ( !result && iter->Next( &mode ) == S_OK )
  60                         {
  61                                 int width = mode->GetWidth();
  62                                 int height = mode->GetHeight();
  63                                 BMDTimeValue duration;
  64                                 BMDTimeScale timescale;
  65                                 mode->GetFrameRate( &duration, &timescale );
  66                                 double fps = (double) timescale / duration;
  67                                 int p = mode->GetFieldDominance() == bmdProgressiveFrame;
  68                                 m_topFieldFirst = mode->GetFieldDominance() == bmdUpperFieldFirst;
  69                                 m_colorspace = ( mode->GetFlags() & bmdDisplayModeColorspaceRec709 ) ? 709 : 601;
  70                                 mlt_log_verbose( getProducer(), "BMD mode %dx%d %.3f fps prog %d tff %d\n", width, height, fps, p, m_topFieldFirst );
  71
  72                                 if ( width == profile->width && p == profile->progressive
  73                                          && ( height + vancLines == profile->height || ( height == 486 && profile->height == 480 + vancLines ) )
  74                                          && fps == mlt_profile_fps( profile ) )
  75                                         result = mode->GetDisplayMode();
  76                         }
  77                 }
  78
  79                 return result;
  80         }
  81
  82 public:
  83
  84         mlt_producer getProducer()
  85                 { return &m_producer; }
  86
  87         ~DeckLinkProducer()
  88         {
  89                 if ( m_decklinkInput )
  90                         m_decklinkInput->Release();
  91                 if ( m_decklink )
  92                         m_decklink->Release();
  93                 if ( m_queue )
  94                 {
  95                         stop();
  96                         mlt_deque_close( m_queue );
  97                         pthread_mutex_destroy( &m_mutex );
  98                         pthread_cond_destroy( &m_condition );
  99                 }
 100         }
 101
 102         bool open( mlt_profile profile, unsigned card =  0 )
 103         {
 104                 IDeckLinkIterator* decklinkIterator = NULL;
 105                 try
 106                 {
 107 #ifdef WIN32
 108                         HRESULT result =  CoInitialize( NULL );
 109                         if ( FAILED( result ) )
 110                                 throw "COM initialization failed";
 111                         result = CoCreateInstance( CLSID_CDeckLinkIterator, NULL, CLSCTX_ALL, IID_IDeckLinkIterator, (void**) &decklinkIterator );
 112                         if ( FAILED( result ) )
 113                                 throw "The DeckLink drivers are not installed.";
 114 #else
 115                         decklinkIterator = CreateDeckLinkIteratorInstance();
 116                         if ( !decklinkIterator )
 117                                 throw "The DeckLink drivers are not installed.";
 118 #endif
 119
 120                         // Connect to the Nth DeckLink instance
 121                         unsigned i = 0;
 122                         do {
 123                                 if ( decklinkIterator->Next( &m_decklink ) != S_OK )
 124                                         throw "DeckLink card not found.";
 125                         } while ( ++i <= card );
 126                         decklinkIterator->Release();
 127
 128                         // Get the input interface
 129                         if ( m_decklink->QueryInterface( IID_IDeckLinkInput, (void**) &m_decklinkInput ) != S_OK )
 130                                 throw "No DeckLink cards support input.";
 131
 132                         // Provide this class as a delegate to the input callback
 133                         m_decklinkInput->SetCallback( this );
 134
 135                         // Initialize other members
 136                         pthread_mutex_init( &m_mutex, NULL );
 137                         pthread_cond_init( &m_condition, NULL );
 138                         m_queue = mlt_deque_init();
 139                         m_started = false;
 140                         m_dropped = 0;
 141                         m_isBuffering = true;
 142                 }
 143                 catch ( const char *error )
 144                 {
 145                         if ( decklinkIterator )
 146                                 decklinkIterator->Release();
 147                         mlt_log_error( getProducer(), "%s\n", error );
 148                         return false;
 149                 }
 150                 return true;
 151         }
 152
 153         bool start( mlt_profile profile = 0 )
 154         {
 155                 if ( m_started )
 156                         return false;
 157                 try
 158                 {
 159                         // Initialize some members
 160                         m_vancLines = mlt_properties_get_int( MLT_PRODUCER_PROPERTIES( getProducer() ), "vanc" );
 161                         if ( m_vancLines == -1 )
 162                                 m_vancLines = profile->height <= 512 ? 26 : 32;
 163
 164                         if ( !profile )
 165                                 profile = mlt_service_profile( MLT_PRODUCER_SERVICE( getProducer() ) );
 166
 167                         // Get the display mode
 168                         BMDDisplayMode displayMode = getDisplayMode( profile, m_vancLines );
 169                         if ( displayMode == (BMDDisplayMode) bmdDisplayModeNotSupported )
 170                                 throw "Profile is not compatible with decklink.";
 171
 172                         // Determine if supports input format detection
 173 #ifdef WIN32
 174                         BOOL doesDetectFormat = FALSE;
 175 #else
 176                         bool doesDetectFormat = false;
 177 #endif
 178                         IDeckLinkAttributes *decklinkAttributes = 0;
 179                         if ( m_decklink->QueryInterface( IID_IDeckLinkAttributes, (void**) &decklinkAttributes ) == S_OK )
 180                         {
 181                                 if ( decklinkAttributes->GetFlag( BMDDeckLinkSupportsInputFormatDetection, &doesDetectFormat ) != S_OK )
 182                                         doesDetectFormat = false;
 183                                 decklinkAttributes->Release();
 184                         }
 185                         mlt_log_verbose( getProducer(), "%s format detection\n", doesDetectFormat ? "supports" : "does not support" );
 186
 187                         // Enable video capture
 188                         BMDPixelFormat pixelFormat = bmdFormat8BitYUV;
 189                         BMDVideoInputFlags flags = doesDetectFormat ? bmdVideoInputEnableFormatDetection : bmdVideoInputFlagDefault;
 190                         if ( S_OK != m_decklinkInput->EnableVideoInput( displayMode, pixelFormat, flags ) )
 191                                 throw "Failed to enable video capture.";
 192
 193                         // Enable audio capture
 194                         BMDAudioSampleRate sampleRate = bmdAudioSampleRate48kHz;
 195                         BMDAudioSampleType sampleType = bmdAudioSampleType16bitInteger;
 196                         int channels = mlt_properties_get_int( MLT_PRODUCER_PROPERTIES( getProducer() ), "channels" );
 197                         if ( S_OK != m_decklinkInput->EnableAudioInput( sampleRate, sampleType, channels ) )
 198                                 throw "Failed to enable audio capture.";
 199
 200                         // Start capture
 201                         m_dropped = 0;
 202                         mlt_properties_set_int( MLT_PRODUCER_PROPERTIES( getProducer() ), "dropped", m_dropped );
 203                         m_started = m_decklinkInput->StartStreams() == S_OK;
 204                         if ( !m_started )
 205                                 throw "Failed to start capture.";
 206                 }
 207                 catch ( const char *error )
 208                 {
 209                         m_decklinkInput->DisableVideoInput();
 210                         mlt_log_error( getProducer(), "%s\n", error );
 211                         return false;
 212                 }
 213                 return true;
 214         }
 215
 216         void stop()
 217         {
 218                 if ( !m_started )
 219                         return;
 220                 m_started = false;
 221
 222                 // Release the wait in getFrame
 223                 pthread_mutex_lock( &m_mutex );
 224                 pthread_cond_broadcast( &m_condition );
 225                 pthread_mutex_unlock( &m_mutex );
 226
 227                 m_decklinkInput->StopStreams();
 228
 229                 // Cleanup queue
 230                 pthread_mutex_lock( &m_mutex );
 231                 while ( mlt_frame frame = (mlt_frame) mlt_deque_pop_back( m_queue ) )
 232                         mlt_frame_close( frame );
 233                 pthread_mutex_unlock( &m_mutex );
 234         }
 235
 236         mlt_frame getFrame()
 237         {
 238                 mlt_frame frame = NULL;
 239                 struct timeval now;
 240                 struct timespec tm;
 241                 double fps = mlt_producer_get_fps( getProducer() );
 242
 243                 // Allow the buffer to fill to the requested initial buffer level.
 244                 if ( m_isBuffering )
 245                 {
 246                         int prefill = mlt_properties_get_int( MLT_PRODUCER_PROPERTIES( getProducer() ), "prefill" );
 247                         int buffer = mlt_properties_get_int( MLT_PRODUCER_PROPERTIES( getProducer() ), "buffer" );
 248
 249                         m_isBuffering = false;
 250                         prefill = prefill > buffer ? buffer : prefill;
 251                         pthread_mutex_lock( &m_mutex );
 252                         while ( mlt_deque_count( m_queue ) < prefill )
 253                         {
 254                                 // Wait up to buffer/fps seconds
 255                                 gettimeofday( &now, NULL );
 256                                 long usec = now.tv_sec * 1000000 + now.tv_usec;
 257                                 usec += 1000000 * buffer / fps;
 258                                 tm.tv_sec = usec / 1000000;
 259                                 tm.tv_nsec = (usec % 1000000) * 1000;
 260                                 if ( pthread_cond_timedwait( &m_condition, &m_mutex, &tm ) )
 261                                         break;
 262                         }
 263                         pthread_mutex_unlock( &m_mutex );
 264                 }
 265
 266                 // Wait if queue is empty
 267                 pthread_mutex_lock( &m_mutex );
 268                 while ( mlt_deque_count( m_queue ) < 1 )
 269                 {
 270                         // Wait up to twice frame duration
 271                         gettimeofday( &now, NULL );
 272                         long usec = now.tv_sec * 1000000 + now.tv_usec;
 273                         usec += 2000000 / fps;
 274                         tm.tv_sec = usec / 1000000;
 275                         tm.tv_nsec = (usec % 1000000) * 1000;
 276                         if ( pthread_cond_timedwait( &m_condition, &m_mutex, &tm ) )
 277                                 // Stop waiting if error (timed out)
 278                                 break;
 279                 }
 280
 281                 // Get the first frame from the queue
 282                 frame = ( mlt_frame ) mlt_deque_pop_front( m_queue );
 283                 pthread_mutex_unlock( &m_mutex );
 284
 285                 // Set frame timestamp and properties
 286                 if ( frame )
 287                 {
 288                         mlt_profile profile = mlt_service_profile( MLT_PRODUCER_SERVICE( getProducer() ) );
 289                         mlt_properties properties = MLT_FRAME_PROPERTIES( frame );
 290                         mlt_properties_set_int( properties, "progressive", profile->progressive );
 291                         mlt_properties_set_int( properties, "meta.media.progressive", profile->progressive );
 292                         mlt_properties_set_int( properties, "top_field_first", m_topFieldFirst );
 293                         mlt_properties_set_double( properties, "aspect_ratio", mlt_profile_sar( profile ) );
 294                         mlt_properties_set_int( properties, "meta.media.sample_aspect_num", profile->sample_aspect_num );
 295                         mlt_properties_set_int( properties, "meta.media.sample_aspect_den", profile->sample_aspect_den );
 296                         mlt_properties_set_int( properties, "meta.media.frame_rate_num", profile->frame_rate_num );
 297                         mlt_properties_set_int( properties, "meta.media.frame_rate_den", profile->frame_rate_den );
 298                         mlt_properties_set_int( properties, "width", profile->width );
 299                         mlt_properties_set_int( properties, "real_width", profile->width );
 300                         mlt_properties_set_int( properties, "meta.media.width", profile->width );
 301                         mlt_properties_set_int( properties, "height", profile->height );
 302                         mlt_properties_set_int( properties, "real_height", profile->height );
 303                         mlt_properties_set_int( properties, "meta.media.height", profile->height );
 304                         mlt_properties_set_int( properties, "format", mlt_image_yuv422 );
 305                         mlt_properties_set_int( properties, "colorspace", m_colorspace );
 306                         mlt_properties_set_int( properties, "meta.media.colorspace", m_colorspace );
 307                         mlt_properties_set_int( properties, "audio_frequency", 48000 );
 308                         mlt_properties_set_int( properties, "audio_channels",
 309                                 mlt_properties_get_int( MLT_PRODUCER_PROPERTIES( getProducer() ), "channels" ) );
 310                 }
 311                 return frame;
 312         }
 313
 314         // *** DeckLink API implementation of IDeckLinkInputCallback *** //
 315
 316         // IUnknown needs only a dummy implementation
 317         virtual HRESULT STDMETHODCALLTYPE QueryInterface( REFIID iid, LPVOID *ppv )
 318                 { return E_NOINTERFACE; }
 319         virtual ULONG STDMETHODCALLTYPE AddRef()
 320                 { return 1; }
 321         virtual ULONG STDMETHODCALLTYPE Release()
 322                 { return 1; }
 323
 324         /************************* DeckLink API Delegate Methods *****************************/
 325
 326         virtual HRESULT STDMETHODCALLTYPE VideoInputFrameArrived(
 327                         IDeckLinkVideoInputFrame* video,
 328                         IDeckLinkAudioInputPacket* audio )
 329         {
 330                 // Create mlt_frame
 331                 mlt_frame frame = mlt_frame_init( MLT_PRODUCER_SERVICE( getProducer() ) );
 332
 333                 // Copy video
 334                 if ( video )
 335                 {
 336                         if ( !( video->GetFlags() & bmdFrameHasNoInputSource ) )
 337                         {
 338                                 int size = video->GetRowBytes() * ( video->GetHeight() + m_vancLines );
 339                                 void* image = mlt_pool_alloc( size );
 340                                 void* buffer = 0;
 341                                 unsigned char* p = (unsigned char*) image;
 342                                 int n = size / 2;
 343 \
 344                                 // Initialize VANC lines to nominal black
 345                                 while ( --n )
 346                                 {
 347                                         *p ++ = 16;
 348                                         *p ++ = 128;
 349                                 }
 350
 351                                 // Capture VANC
 352                                 if ( m_vancLines > 0 )
 353                                 {
 354                                         IDeckLinkVideoFrameAncillary* vanc = 0;
 355                                         if ( video->GetAncillaryData( &vanc ) == S_OK && vanc )
 356                                         {
 357                                                 for ( int i = 1; i < m_vancLines + 1; i++ )
 358                                                 {
 359                                                         if ( vanc->GetBufferForVerticalBlankingLine( i, &buffer ) == S_OK )
 360                                                                 swab( (char*) buffer, (char*) image + ( i - 1 ) * video->GetRowBytes(), video->GetRowBytes() );
 361                                                         else
 362                                                                 mlt_log_debug( getProducer(), "failed capture vanc line %d\n", i );
 363                                                 }
 364                                                 vanc->Release();
 365                                         }
 366                                 }
 367
 368                                 // Capture image
 369                                 video->GetBytes( &buffer );
 370                                 if ( image && buffer )
 371                                 {
 372                                         size =  video->GetRowBytes() * video->GetHeight();
 373                                         swab( (char*) buffer, (char*) image + m_vancLines * video->GetRowBytes(), size );
 374                                         mlt_frame_set_image( frame, (uint8_t*) image, size, mlt_pool_release );
 375                                 }
 376                                 else if ( image )
 377                                 {
 378                                         mlt_log_verbose( getProducer(), "no video\n" );
 379                                         mlt_pool_release( image );
 380                                 }
 381                         }
 382                         else
 383                         {
 384                                 mlt_log_verbose( getProducer(), "no signal\n" );
 385                                 mlt_frame_close( frame );
 386                                 frame = 0;
 387                         }
 388
 389                         // Get timecode
 390                         IDeckLinkTimecode* timecode = 0;
 391                         if ( video->GetTimecode( bmdTimecodeVITC, &timecode ) == S_OK && timecode )
 392                         {
 393                                 const char* timecodeString = 0;
 394
 395 #ifdef WIN32
 396                                 if ( timecode->GetString( (BSTR*) &timecodeString ) == S_OK )
 397 #else
 398                                 if ( timecode->GetString( &timecodeString ) == S_OK )
 399 #endif
 400                                 {
 401                                         mlt_properties_set( MLT_FRAME_PROPERTIES( frame ), "meta.attr.vitc.markup", timecodeString );
 402                                         mlt_log_debug( getProducer(), "timecode %s\n", timecodeString );
 403                                 }
 404                                 if ( timecodeString )
 405                                         free( (void*) timecodeString );
 406                                 timecode->Release();
 407                         }
 408                 }
 409                 else
 410                 {
 411                         mlt_log_verbose( getProducer(), "no video\n" );
 412                         mlt_frame_close( frame );
 413                         frame = 0;
 414                 }
 415
 416                 // Copy audio
 417                 if ( frame && audio )
 418                 {
 419                         int channels = mlt_properties_get_int( MLT_PRODUCER_PROPERTIES( getProducer() ), "channels" );
 420                         int size = audio->GetSampleFrameCount() * channels * sizeof(int16_t);
 421                         mlt_audio_format format = mlt_audio_s16;
 422                         void* pcm = mlt_pool_alloc( size );
 423                         void* buffer = 0;
 424
 425                         audio->GetBytes( &buffer );
 426                         if ( buffer )
 427                         {
 428                                 memcpy( pcm, buffer, size );
 429                                 mlt_frame_set_audio( frame, pcm, format, size, mlt_pool_release );
 430                                 mlt_properties_set_int( MLT_FRAME_PROPERTIES(frame), "audio_samples", audio->GetSampleFrameCount() );
 431                         }
 432                         else
 433                         {
 434                                 mlt_log_verbose( getProducer(), "no audio\n" );
 435                                 mlt_pool_release( pcm );
 436                         }
 437                 }
 438                 else
 439                 {
 440                         mlt_log_verbose( getProducer(), "no audio\n" );
 441                 }
 442
 443                 // Put frame in queue
 444                 if ( frame )
 445                 {
 446                         int queueMax = mlt_properties_get_int( MLT_PRODUCER_PROPERTIES( getProducer() ), "buffer" );
 447                         pthread_mutex_lock( &m_mutex );
 448                         if ( mlt_deque_count( m_queue ) < queueMax )
 449                         {
 450                                 mlt_deque_push_back( m_queue, frame );
 451                                 pthread_cond_broadcast( &m_condition );
 452                         }
 453                         else
 454                         {
 455                                 mlt_frame_close( frame );
 456                                 mlt_properties_set_int( MLT_PRODUCER_PROPERTIES( getProducer() ), "dropped", ++m_dropped );
 457                                 mlt_log_warning( getProducer(), "frame dropped %d\n", m_dropped );
 458                         }
 459                         pthread_mutex_unlock( &m_mutex );
 460                 }
 461
 462                 return S_OK;
 463         }
 464
 465         virtual HRESULT STDMETHODCALLTYPE VideoInputFormatChanged(
 466                         BMDVideoInputFormatChangedEvents events,
 467                         IDeckLinkDisplayMode* mode,
 468                         BMDDetectedVideoInputFormatFlags flags )
 469         {
 470                 mlt_profile profile = mlt_service_profile( MLT_PRODUCER_SERVICE( getProducer() ) );
 471                 if ( events & bmdVideoInputDisplayModeChanged )
 472                 {
 473                         BMDTimeValue duration;
 474                         BMDTimeScale timescale;
 475                         mode->GetFrameRate( &duration, &timescale );
 476                         profile->width = mode->GetWidth();
 477                         profile->height = mode->GetHeight() + m_vancLines;
 478                         profile->frame_rate_num = timescale;
 479                         profile->frame_rate_den = duration;
 480                         if ( profile->width == 720 )
 481                         {
 482                                 if ( profile->height == 576 )
 483                                 {
 484                                         profile->sample_aspect_num = 16;
 485                                         profile->sample_aspect_den = 15;
 486                                 }
 487                                 else
 488                                 {
 489                                         profile->sample_aspect_num = 8;
 490                                         profile->sample_aspect_den = 9;
 491                                 }
 492                                 profile->display_aspect_num = 4;
 493                                 profile->display_aspect_den = 3;
 494                         }
 495                         else
 496                         {
 497                                 profile->sample_aspect_num = 1;
 498                                 profile->sample_aspect_den = 1;
 499                                 profile->display_aspect_num = 16;
 500                                 profile->display_aspect_den = 9;
 501                         }
 502                         free( profile->description );
 503                         profile->description = strdup( "decklink" );
 504                         mlt_log_verbose( getProducer(), "format changed %dx%d %.3f fps\n",
 505                                 profile->width, profile->height, (double) profile->frame_rate_num / profile->frame_rate_den );
 506                 }
 507                 if ( events & bmdVideoInputFieldDominanceChanged )
 508                 {
 509                         profile->progressive = mode->GetFieldDominance() == bmdProgressiveFrame;
 510                         m_topFieldFirst = mode->GetFieldDominance() == bmdUpperFieldFirst;
 511                         mlt_log_verbose( getProducer(), "field dominance changed prog %d tff %d\n",
 512                                 profile->progressive, m_topFieldFirst );
 513                 }
 514                 if ( events & bmdVideoInputColorspaceChanged )
 515                 {
 516                         profile->colorspace = m_colorspace =
 517                                 ( mode->GetFlags() & bmdDisplayModeColorspaceRec709 ) ? 709 : 601;
 518                         mlt_log_verbose( getProducer(), "colorspace changed %d\n", profile->colorspace );
 519                 }
 520                 return S_OK;
 521         }
 522 };
 523
 524 static int get_audio( mlt_frame frame, int16_t **buffer, mlt_audio_format *format, int *frequency, int *channels, int *samples )
 525 {
 526         return mlt_frame_get_audio( frame, (void**) buffer, format, frequency, channels, samples );
 527 }
 528
 529 static int get_image( mlt_frame frame, uint8_t **buffer, mlt_image_format *format, int *width, int *height, int writable )
 530 {
 531         return mlt_frame_get_image( frame, buffer, format, width, height, writable );
 532 }
 533
 534 static int get_frame( mlt_producer producer, mlt_frame_ptr frame, int index )
 535 {
 536         DeckLinkProducer* decklink = (DeckLinkProducer*) producer->child;
 537
 538         // Start if needed
 539         decklink->start( mlt_service_profile( MLT_PRODUCER_SERVICE( producer ) ) );
 540
 541         // Get the next frame from the decklink object
 542         *frame = decklink->getFrame();
 543         if ( !*frame )
 544                 *frame = mlt_frame_init( MLT_PRODUCER_SERVICE( producer ) );
 545
 546         // Calculate the next timecode
 547         mlt_frame_set_position( *frame, mlt_producer_position( producer ) );
 548         mlt_producer_prepare_next( producer );
 549
 550         // Add audio and video getters
 551         mlt_frame_push_audio( *frame, (void*) get_audio );
 552         mlt_frame_push_get_image( *frame, get_image );
 553
 554         return 0;
 555 }
 556
 557 static void producer_close( mlt_producer producer )
 558 {
 559         producer->close = NULL;
 560         mlt_producer_close( producer );
 561         delete (DeckLinkProducer*) producer->child;
 562 }
 563
 564 extern "C" {
 565
 566 /** Initialise the producer.
 567  */
 568
 569 mlt_producer producer_decklink_init( mlt_profile profile, mlt_service_type type, const char *id, char *arg )
 570 {
 571         // Allocate the producer
 572         DeckLinkProducer* decklink = new DeckLinkProducer();
 573         mlt_producer producer = NULL;
 574
 575         // If allocated and initializes
 576         if ( decklink && !mlt_producer_init( decklink->getProducer(), decklink ) )
 577         {
 578                 if ( decklink->open( profile, arg? atoi( arg ) : 0 ) )
 579                 {
 580                         producer = decklink->getProducer();
 581                         mlt_properties properties = MLT_PRODUCER_PROPERTIES( producer );
 582
 583                         // Set callbacks
 584                         producer->close = (mlt_destructor) producer_close;
 585                         producer->get_frame = get_frame;
 586
 587                         // Set properties
 588                         mlt_properties_set( properties, "resource", arg? arg : "0" );
 589                         mlt_properties_set_int( properties, "channels", 2 );
 590                         mlt_properties_set_int( properties, "buffer", 25 );
 591                         mlt_properties_set_int( properties, "prefill", 25 );
 592
 593                         // These properties effectively make it infinite.
 594                         mlt_properties_set_int( properties, "length", INT_MAX );
 595                         mlt_properties_set_int( properties, "out", INT_MAX - 1 );
 596                         mlt_properties_set( properties, "eof", "loop" );
 597                 }
 598         }
 599
 600         return producer;
 601 }
 602
 603 }