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     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         void setProducer( mlt_producer producer )
  85                 { m_producer = producer; }
  86
  87         mlt_producer getProducer() const
  88                 { return m_producer; }
  89
  90         ~DeckLinkProducer()
  91         {
  92                 if ( m_decklinkInput )
  93                         m_decklinkInput->Release();
  94                 if ( m_decklink )
  95                         m_decklink->Release();
  96                 if ( m_queue )
  97                 {
  98                         stop();
  99                         mlt_deque_close( m_queue );
 100                         pthread_mutex_destroy( &m_mutex );
 101                         pthread_cond_destroy( &m_condition );
 102                 }
 103         }
 104
 105         bool open( unsigned card =  0 )
 106         {
 107                 IDeckLinkIterator* decklinkIterator = NULL;
 108                 try
 109                 {
 110 #ifdef WIN32
 111                         HRESULT result =  CoInitialize( NULL );
 112                         if ( FAILED( result ) )
 113                                 throw "COM initialization failed";
 114                         result = CoCreateInstance( CLSID_CDeckLinkIterator, NULL, CLSCTX_ALL, IID_IDeckLinkIterator, (void**) &decklinkIterator );
 115                         if ( FAILED( result ) )
 116                                 throw "The DeckLink drivers are not installed.";
 117 #else
 118                         decklinkIterator = CreateDeckLinkIteratorInstance();
 119                         if ( !decklinkIterator )
 120                                 throw "The DeckLink drivers are not installed.";
 121 #endif
 122
 123                         // Connect to the Nth DeckLink instance
 124                         unsigned i = 0;
 125                         do {
 126                                 if ( decklinkIterator->Next( &m_decklink ) != S_OK )
 127                                         throw "DeckLink card not found.";
 128                         } while ( ++i <= card );
 129                         decklinkIterator->Release();
 130
 131                         // Get the input interface
 132                         if ( m_decklink->QueryInterface( IID_IDeckLinkInput, (void**) &m_decklinkInput ) != S_OK )
 133                                 throw "No DeckLink cards support input.";
 134
 135                         // Provide this class as a delegate to the input callback
 136                         m_decklinkInput->SetCallback( this );
 137
 138                         // Initialize other members
 139                         pthread_mutex_init( &m_mutex, NULL );
 140                         pthread_cond_init( &m_condition, NULL );
 141                         m_queue = mlt_deque_init();
 142                         m_started = false;
 143                         m_dropped = 0;
 144                         m_isBuffering = true;
 145                 }
 146                 catch ( const char *error )
 147                 {
 148                         if ( decklinkIterator )
 149                                 decklinkIterator->Release();
 150                         mlt_log_error( getProducer(), "%s\n", error );
 151                         return false;
 152                 }
 153                 return true;
 154         }
 155
 156         bool start( mlt_profile profile = 0 )
 157         {
 158                 if ( m_started )
 159                         return false;
 160                 try
 161                 {
 162                         // Initialize some members
 163                         m_vancLines = mlt_properties_get_int( MLT_PRODUCER_PROPERTIES( getProducer() ), "vanc" );
 164                         if ( m_vancLines == -1 )
 165                                 m_vancLines = profile->height <= 512 ? 26 : 32;
 166
 167                         if ( !profile )
 168                                 profile = mlt_service_profile( MLT_PRODUCER_SERVICE( getProducer() ) );
 169
 170                         // Get the display mode
 171                         BMDDisplayMode displayMode = getDisplayMode( profile, m_vancLines );
 172                         if ( displayMode == (BMDDisplayMode) bmdDisplayModeNotSupported )
 173                                 throw "Profile is not compatible with decklink.";
 174
 175                         // Determine if supports input format detection
 176 #ifdef WIN32
 177                         BOOL doesDetectFormat = FALSE;
 178 #else
 179                         bool doesDetectFormat = false;
 180 #endif
 181                         IDeckLinkAttributes *decklinkAttributes = 0;
 182                         if ( m_decklink->QueryInterface( IID_IDeckLinkAttributes, (void**) &decklinkAttributes ) == S_OK )
 183                         {
 184                                 if ( decklinkAttributes->GetFlag( BMDDeckLinkSupportsInputFormatDetection, &doesDetectFormat ) != S_OK )
 185                                         doesDetectFormat = false;
 186                                 decklinkAttributes->Release();
 187                         }
 188                         mlt_log_verbose( getProducer(), "%s format detection\n", doesDetectFormat ? "supports" : "does not support" );
 189
 190                         // Enable video capture
 191                         BMDPixelFormat pixelFormat = bmdFormat8BitYUV;
 192                         BMDVideoInputFlags flags = doesDetectFormat ? bmdVideoInputEnableFormatDetection : bmdVideoInputFlagDefault;
 193                         if ( S_OK != m_decklinkInput->EnableVideoInput( displayMode, pixelFormat, flags ) )
 194                                 throw "Failed to enable video capture.";
 195
 196                         // Enable audio capture
 197                         BMDAudioSampleRate sampleRate = bmdAudioSampleRate48kHz;
 198                         BMDAudioSampleType sampleType = bmdAudioSampleType16bitInteger;
 199                         int channels = mlt_properties_get_int( MLT_PRODUCER_PROPERTIES( getProducer() ), "channels" );
 200                         if ( S_OK != m_decklinkInput->EnableAudioInput( sampleRate, sampleType, channels ) )
 201                                 throw "Failed to enable audio capture.";
 202
 203                         // Start capture
 204                         m_dropped = 0;
 205                         mlt_properties_set_int( MLT_PRODUCER_PROPERTIES( getProducer() ), "dropped", m_dropped );
 206                         m_started = m_decklinkInput->StartStreams() == S_OK;
 207                         if ( !m_started )
 208                                 throw "Failed to start capture.";
 209                 }
 210                 catch ( const char *error )
 211                 {
 212                         m_decklinkInput->DisableVideoInput();
 213                         mlt_log_error( getProducer(), "%s\n", error );
 214                         return false;
 215                 }
 216                 return true;
 217         }
 218
 219         void stop()
 220         {
 221                 if ( !m_started )
 222                         return;
 223                 m_started = false;
 224
 225                 // Release the wait in getFrame
 226                 pthread_mutex_lock( &m_mutex );
 227                 pthread_cond_broadcast( &m_condition );
 228                 pthread_mutex_unlock( &m_mutex );
 229
 230                 m_decklinkInput->StopStreams();
 231
 232                 // Cleanup queue
 233                 pthread_mutex_lock( &m_mutex );
 234                 while ( mlt_frame frame = (mlt_frame) mlt_deque_pop_back( m_queue ) )
 235                         mlt_frame_close( frame );
 236                 pthread_mutex_unlock( &m_mutex );
 237         }
 238
 239         mlt_frame getFrame()
 240         {
 241                 mlt_frame frame = NULL;
 242                 struct timeval now;
 243                 struct timespec tm;
 244                 double fps = mlt_producer_get_fps( getProducer() );
 245
 246                 // Allow the buffer to fill to the requested initial buffer level.
 247                 if ( m_isBuffering )
 248                 {
 249                         int prefill = mlt_properties_get_int( MLT_PRODUCER_PROPERTIES( getProducer() ), "prefill" );
 250                         int buffer = mlt_properties_get_int( MLT_PRODUCER_PROPERTIES( getProducer() ), "buffer" );
 251
 252                         m_isBuffering = false;
 253                         prefill = prefill > buffer ? buffer : prefill;
 254                         pthread_mutex_lock( &m_mutex );
 255                         while ( mlt_deque_count( m_queue ) < prefill )
 256                         {
 257                                 // Wait up to buffer/fps seconds
 258                                 gettimeofday( &now, NULL );
 259                                 long usec = now.tv_sec * 1000000 + now.tv_usec;
 260                                 usec += 1000000 * buffer / fps;
 261                                 tm.tv_sec = usec / 1000000;
 262                                 tm.tv_nsec = (usec % 1000000) * 1000;
 263                                 if ( pthread_cond_timedwait( &m_condition, &m_mutex, &tm ) )
 264                                         break;
 265                         }
 266                         pthread_mutex_unlock( &m_mutex );
 267                 }
 268
 269                 // Wait if queue is empty
 270                 pthread_mutex_lock( &m_mutex );
 271                 while ( mlt_deque_count( m_queue ) < 1 )
 272                 {
 273                         // Wait up to twice frame duration
 274                         gettimeofday( &now, NULL );
 275                         long usec = now.tv_sec * 1000000 + now.tv_usec;
 276                         usec += 2000000 / fps;
 277                         tm.tv_sec = usec / 1000000;
 278                         tm.tv_nsec = (usec % 1000000) * 1000;
 279                         if ( pthread_cond_timedwait( &m_condition, &m_mutex, &tm ) )
 280                                 // Stop waiting if error (timed out)
 281                                 break;
 282                 }
 283
 284                 // Get the first frame from the queue
 285                 frame = ( mlt_frame ) mlt_deque_pop_front( m_queue );
 286                 pthread_mutex_unlock( &m_mutex );
 287
 288                 // Set frame timestamp and properties
 289                 if ( frame )
 290                 {
 291                         mlt_profile profile = mlt_service_profile( MLT_PRODUCER_SERVICE( getProducer() ) );
 292                         mlt_properties properties = MLT_FRAME_PROPERTIES( frame );
 293                         mlt_properties_set_int( properties, "progressive", profile->progressive );
 294                         mlt_properties_set_int( properties, "meta.media.progressive", profile->progressive );
 295                         mlt_properties_set_int( properties, "top_field_first", m_topFieldFirst );
 296                         mlt_properties_set_double( properties, "aspect_ratio", mlt_profile_sar( profile ) );
 297                         mlt_properties_set_int( properties, "meta.media.sample_aspect_num", profile->sample_aspect_num );
 298                         mlt_properties_set_int( properties, "meta.media.sample_aspect_den", profile->sample_aspect_den );
 299                         mlt_properties_set_int( properties, "meta.media.frame_rate_num", profile->frame_rate_num );
 300                         mlt_properties_set_int( properties, "meta.media.frame_rate_den", profile->frame_rate_den );
 301                         mlt_properties_set_int( properties, "width", profile->width );
 302                         mlt_properties_set_int( properties, "real_width", profile->width );
 303                         mlt_properties_set_int( properties, "meta.media.width", profile->width );
 304                         mlt_properties_set_int( properties, "height", profile->height );
 305                         mlt_properties_set_int( properties, "real_height", profile->height );
 306                         mlt_properties_set_int( properties, "meta.media.height", profile->height );
 307                         mlt_properties_set_int( properties, "format", mlt_image_yuv422 );
 308                         mlt_properties_set_int( properties, "colorspace", m_colorspace );
 309                         mlt_properties_set_int( properties, "meta.media.colorspace", m_colorspace );
 310                         mlt_properties_set_int( properties, "audio_frequency", 48000 );
 311                         mlt_properties_set_int( properties, "audio_channels",
 312                                 mlt_properties_get_int( MLT_PRODUCER_PROPERTIES( getProducer() ), "channels" ) );
 313                 }
 314                 return frame;
 315         }
 316
 317         // *** DeckLink API implementation of IDeckLinkInputCallback *** //
 318
 319         // IUnknown needs only a dummy implementation
 320         virtual HRESULT STDMETHODCALLTYPE QueryInterface( REFIID iid, LPVOID *ppv )
 321                 { return E_NOINTERFACE; }
 322         virtual ULONG STDMETHODCALLTYPE AddRef()
 323                 { return 1; }
 324         virtual ULONG STDMETHODCALLTYPE Release()
 325                 { return 1; }
 326
 327         /************************* DeckLink API Delegate Methods *****************************/
 328
 329         virtual HRESULT STDMETHODCALLTYPE VideoInputFrameArrived(
 330                         IDeckLinkVideoInputFrame* video,
 331                         IDeckLinkAudioInputPacket* audio )
 332         {
 333                 // Create mlt_frame
 334                 mlt_frame frame = mlt_frame_init( MLT_PRODUCER_SERVICE( getProducer() ) );
 335
 336                 // Copy video
 337                 if ( video )
 338                 {
 339                         if ( !( video->GetFlags() & bmdFrameHasNoInputSource ) )
 340                         {
 341                                 int size = video->GetRowBytes() * ( video->GetHeight() + m_vancLines );
 342                                 void* image = mlt_pool_alloc( size );
 343                                 void* buffer = 0;
 344                                 unsigned char* p = (unsigned char*) image;
 345                                 int n = size / 2;
 346 \
 347                                 // Initialize VANC lines to nominal black
 348                                 while ( --n )
 349                                 {
 350                                         *p ++ = 16;
 351                                         *p ++ = 128;
 352                                 }
 353
 354                                 // Capture VANC
 355                                 if ( m_vancLines > 0 )
 356                                 {
 357                                         IDeckLinkVideoFrameAncillary* vanc = 0;
 358                                         if ( video->GetAncillaryData( &vanc ) == S_OK && vanc )
 359                                         {
 360                                                 for ( int i = 1; i < m_vancLines + 1; i++ )
 361                                                 {
 362                                                         if ( vanc->GetBufferForVerticalBlankingLine( i, &buffer ) == S_OK )
 363                                                                 swab( (char*) buffer, (char*) image + ( i - 1 ) * video->GetRowBytes(), video->GetRowBytes() );
 364                                                         else
 365                                                                 mlt_log_debug( getProducer(), "failed capture vanc line %d\n", i );
 366                                                 }
 367                                                 vanc->Release();
 368                                         }
 369                                 }
 370
 371                                 // Capture image
 372                                 video->GetBytes( &buffer );
 373                                 if ( image && buffer )
 374                                 {
 375                                         size =  video->GetRowBytes() * video->GetHeight();
 376                                         swab( (char*) buffer, (char*) image + m_vancLines * video->GetRowBytes(), size );
 377                                         mlt_frame_set_image( frame, (uint8_t*) image, size, mlt_pool_release );
 378                                 }
 379                                 else if ( image )
 380                                 {
 381                                         mlt_log_verbose( getProducer(), "no video\n" );
 382                                         mlt_pool_release( image );
 383                                 }
 384                         }
 385                         else
 386                         {
 387                                 mlt_log_verbose( getProducer(), "no signal\n" );
 388                                 mlt_frame_close( frame );
 389                                 frame = 0;
 390                         }
 391
 392                         // Get timecode
 393                         IDeckLinkTimecode* timecode = 0;
 394                         if ( video->GetTimecode( bmdTimecodeVITC, &timecode ) == S_OK && timecode )
 395                         {
 396                                 const char* timecodeString = 0;
 397
 398 #ifdef WIN32
 399                                 if ( timecode->GetString( (BSTR*) &timecodeString ) == S_OK )
 400 #else
 401                                 if ( timecode->GetString( &timecodeString ) == S_OK )
 402 #endif
 403                                 {
 404                                         mlt_properties_set( MLT_FRAME_PROPERTIES( frame ), "meta.attr.vitc.markup", timecodeString );
 405                                         mlt_log_debug( getProducer(), "timecode %s\n", timecodeString );
 406                                 }
 407                                 if ( timecodeString )
 408                                         free( (void*) timecodeString );
 409                                 timecode->Release();
 410                         }
 411                 }
 412                 else
 413                 {
 414                         mlt_log_verbose( getProducer(), "no video\n" );
 415                         mlt_frame_close( frame );
 416                         frame = 0;
 417                 }
 418
 419                 // Copy audio
 420                 if ( frame && audio )
 421                 {
 422                         int channels = mlt_properties_get_int( MLT_PRODUCER_PROPERTIES( getProducer() ), "channels" );
 423                         int size = audio->GetSampleFrameCount() * channels * sizeof(int16_t);
 424                         mlt_audio_format format = mlt_audio_s16;
 425                         void* pcm = mlt_pool_alloc( size );
 426                         void* buffer = 0;
 427
 428                         audio->GetBytes( &buffer );
 429                         if ( buffer )
 430                         {
 431                                 memcpy( pcm, buffer, size );
 432                                 mlt_frame_set_audio( frame, pcm, format, size, mlt_pool_release );
 433                                 mlt_properties_set_int( MLT_FRAME_PROPERTIES(frame), "audio_samples", audio->GetSampleFrameCount() );
 434                         }
 435                         else
 436                         {
 437                                 mlt_log_verbose( getProducer(), "no audio\n" );
 438                                 mlt_pool_release( pcm );
 439                         }
 440                 }
 441                 else
 442                 {
 443                         mlt_log_verbose( getProducer(), "no audio\n" );
 444                 }
 445
 446                 // Put frame in queue
 447                 if ( frame )
 448                 {
 449                         int queueMax = mlt_properties_get_int( MLT_PRODUCER_PROPERTIES( getProducer() ), "buffer" );
 450                         pthread_mutex_lock( &m_mutex );
 451                         if ( mlt_deque_count( m_queue ) < queueMax )
 452                         {
 453                                 mlt_deque_push_back( m_queue, frame );
 454                                 pthread_cond_broadcast( &m_condition );
 455                         }
 456                         else
 457                         {
 458                                 mlt_frame_close( frame );
 459                                 mlt_properties_set_int( MLT_PRODUCER_PROPERTIES( getProducer() ), "dropped", ++m_dropped );
 460                                 mlt_log_warning( getProducer(), "frame dropped %d\n", m_dropped );
 461                         }
 462                         pthread_mutex_unlock( &m_mutex );
 463                 }
 464
 465                 return S_OK;
 466         }
 467
 468         virtual HRESULT STDMETHODCALLTYPE VideoInputFormatChanged(
 469                         BMDVideoInputFormatChangedEvents events,
 470                         IDeckLinkDisplayMode* mode,
 471                         BMDDetectedVideoInputFormatFlags flags )
 472         {
 473                 mlt_profile profile = mlt_service_profile( MLT_PRODUCER_SERVICE( getProducer() ) );
 474                 if ( events & bmdVideoInputDisplayModeChanged )
 475                 {
 476                         BMDTimeValue duration;
 477                         BMDTimeScale timescale;
 478                         mode->GetFrameRate( &duration, &timescale );
 479                         profile->width = mode->GetWidth();
 480                         profile->height = mode->GetHeight() + m_vancLines;
 481                         profile->frame_rate_num = timescale;
 482                         profile->frame_rate_den = duration;
 483                         if ( profile->width == 720 )
 484                         {
 485                                 if ( profile->height == 576 )
 486                                 {
 487                                         profile->sample_aspect_num = 16;
 488                                         profile->sample_aspect_den = 15;
 489                                 }
 490                                 else
 491                                 {
 492                                         profile->sample_aspect_num = 8;
 493                                         profile->sample_aspect_den = 9;
 494                                 }
 495                                 profile->display_aspect_num = 4;
 496                                 profile->display_aspect_den = 3;
 497                         }
 498                         else
 499                         {
 500                                 profile->sample_aspect_num = 1;
 501                                 profile->sample_aspect_den = 1;
 502                                 profile->display_aspect_num = 16;
 503                                 profile->display_aspect_den = 9;
 504                         }
 505                         free( profile->description );
 506                         profile->description = strdup( "decklink" );
 507                         mlt_log_verbose( getProducer(), "format changed %dx%d %.3f fps\n",
 508                                 profile->width, profile->height, (double) profile->frame_rate_num / profile->frame_rate_den );
 509                 }
 510                 if ( events & bmdVideoInputFieldDominanceChanged )
 511                 {
 512                         profile->progressive = mode->GetFieldDominance() == bmdProgressiveFrame;
 513                         m_topFieldFirst = mode->GetFieldDominance() == bmdUpperFieldFirst;
 514                         mlt_log_verbose( getProducer(), "field dominance changed prog %d tff %d\n",
 515                                 profile->progressive, m_topFieldFirst );
 516                 }
 517                 if ( events & bmdVideoInputColorspaceChanged )
 518                 {
 519                         profile->colorspace = m_colorspace =
 520                                 ( mode->GetFlags() & bmdDisplayModeColorspaceRec709 ) ? 709 : 601;
 521                         mlt_log_verbose( getProducer(), "colorspace changed %d\n", profile->colorspace );
 522                 }
 523                 return S_OK;
 524         }
 525 };
 526
 527 static int get_audio( mlt_frame frame, int16_t **buffer, mlt_audio_format *format, int *frequency, int *channels, int *samples )
 528 {
 529         return mlt_frame_get_audio( frame, (void**) buffer, format, frequency, channels, samples );
 530 }
 531
 532 static int get_image( mlt_frame frame, uint8_t **buffer, mlt_image_format *format, int *width, int *height, int writable )
 533 {
 534         return mlt_frame_get_image( frame, buffer, format, width, height, writable );
 535 }
 536
 537 static int get_frame( mlt_producer producer, mlt_frame_ptr frame, int index )
 538 {
 539         DeckLinkProducer* decklink = (DeckLinkProducer*) producer->child;
 540         mlt_position pos = mlt_producer_position( producer );
 541         mlt_position end = mlt_producer_get_playtime( producer );
 542         end = ( mlt_producer_get_length( producer ) < end ? mlt_producer_get_length( producer ) : end ) - 1;
 543
 544         // Re-open if needed
 545         if ( !decklink && pos < end )
 546         {
 547                 producer->child = decklink = new DeckLinkProducer();
 548                 decklink->setProducer( producer );
 549                 decklink->open( mlt_properties_get_int( MLT_PRODUCER_PROPERTIES(producer), "resource" ) );
 550         }
 551
 552         // Start if needed
 553         if ( decklink )
 554         {
 555                 decklink->start( mlt_service_profile( MLT_PRODUCER_SERVICE( producer ) ) );
 556
 557                 // Get the next frame from the decklink object
 558                 if ( ( *frame = decklink->getFrame() ))
 559                 {
 560                         // Add audio and video getters
 561                         mlt_frame_push_audio( *frame, (void*) get_audio );
 562                         mlt_frame_push_get_image( *frame, get_image );
 563                 }
 564         }
 565         if ( !*frame )
 566                 *frame = mlt_frame_init( MLT_PRODUCER_SERVICE(producer) );
 567
 568         // Calculate the next timecode
 569         mlt_frame_set_position( *frame, mlt_producer_position( producer ) );
 570         mlt_producer_prepare_next( producer );
 571
 572         // Close DeckLink if at end
 573         if ( pos >= end && decklink )
 574         {
 575                 decklink->stop();
 576                 delete decklink;
 577                 producer->child = NULL;
 578         }
 579
 580         return 0;
 581 }
 582
 583 static void producer_close( mlt_producer producer )
 584 {
 585         delete (DeckLinkProducer*) producer->child;
 586         producer->close = NULL;
 587         mlt_producer_close( producer );
 588 }
 589
 590 extern "C" {
 591
 592 /** Initialise the producer.
 593  */
 594
 595 mlt_producer producer_decklink_init( mlt_profile profile, mlt_service_type type, const char *id, char *arg )
 596 {
 597         // Allocate the producer
 598         DeckLinkProducer* decklink = new DeckLinkProducer();
 599         mlt_producer producer = (mlt_producer) calloc( 1, sizeof( *producer ) );
 600
 601         // If allocated and initializes
 602         if ( decklink && !mlt_producer_init( producer, decklink ) )
 603         {
 604                 if ( decklink->open( arg? atoi( arg ) : 0 ) )
 605                 {
 606                         mlt_properties properties = MLT_PRODUCER_PROPERTIES( producer );
 607
 608                         // Close DeckLink and defer re-open to get_frame
 609                         delete decklink;
 610                         producer->child = NULL;
 611
 612                         // Set callbacks
 613                         producer->close = (mlt_destructor) producer_close;
 614                         producer->get_frame = get_frame;
 615
 616                         // Set properties
 617                         mlt_properties_set( properties, "resource", (arg && strcmp( arg, ""))? arg : "0" );
 618                         mlt_properties_set_int( properties, "channels", 2 );
 619                         mlt_properties_set_int( properties, "buffer", 25 );
 620                         mlt_properties_set_int( properties, "prefill", 25 );
 621
 622                         // These properties effectively make it infinite.
 623                         mlt_properties_set_int( properties, "length", INT_MAX );
 624                         mlt_properties_set_int( properties, "out", INT_MAX - 1 );
 625                         mlt_properties_set( properties, "eof", "loop" );
 626                 }
 627         }
 628
 629         return producer;
 630 }
 631
 632 }