C++ IDeckLinkOutput::StartScheduledPlayback方法代码示例

 void start_video( ) {
     if (deckLinkOutput->StartScheduledPlayback(0, 100, 1.0) != S_OK) {
         throw std::runtime_error(
             "Failed to start scheduled playback!\n"
         );
     }
 }

void BMDOutputDelegate::StartRunning ()
{
	IDeckLinkDisplayMode*	videoDisplayMode = NULL;
	
	// Get the display mode for 1080i 59.95 - mode 6
	// Changed to NTSC 23.98 - JB 20110215
	videoDisplayMode = GetDisplayModeByIndex(1);

	if (!videoDisplayMode)
		return;

	m_frameWidth = videoDisplayMode->GetWidth();
	m_frameHeight = videoDisplayMode->GetHeight();
	videoDisplayMode->GetFrameRate(&m_frameDuration, &m_frameTimescale);
	
	// Calculate the number of frames per second, rounded up to the nearest integer.  For example, for NTSC (29.97 FPS), framesPerSecond == 30.
	m_framesPerSecond = (unsigned long)((m_frameTimescale + (m_frameDuration-1))  /  m_frameDuration);
	
	
	QImage image(m_frameWidth,m_frameHeight, QImage::Format_ARGB32);
	image.fill(Qt::green);
	//m_frame = VideoFramePtr(new VideoFrame(image, 1000/30));
	
	HRESULT res;
	
	// Set the video output mode
	if (m_deckLinkOutput->EnableVideoOutput(videoDisplayMode->GetDisplayMode(), bmdVideoOutputFlagDefault) != S_OK)
	{
		//fprintf(stderr, "Failed to enable video output\n");
		qDebug() << "BMDOutputDelegate::StartRunning(): Failed to EnableVideoOutput()";
		goto bail;
	}
	
	res = m_deckLinkOutput->CreateVideoFrame(
		m_frameWidth,
		m_frameHeight,
		m_frameWidth * 4,
		bmdFormat8BitBGRA, 
		bmdFrameFlagDefault,
		&m_rgbFrame);
	
	if(res != S_OK)
	{
		qDebug() << "BMDOutputDelegate::StartRunning: Error creating RGB frame, res:"<<res;
		goto bail;
	}
	
	res = m_deckLinkOutput->CreateVideoFrame(
		m_frameWidth,
		m_frameHeight,
		m_frameWidth * 2,
		bmdFormat8BitYUV, 
		bmdFrameFlagDefault,
		&m_yuvFrame);
	
	if(res != S_OK)
	{
		qDebug() << "BMDOutputDelegate::StartRunning: Error creating YUV frame, res:"<<res;
		goto bail;
	}


// 	// Generate a frame of black
// 	if (m_deckLinkOutput->CreateVideoFrame(m_frameWidth, m_frameHeight, m_frameWidth*2, bmdFormat8BitYUV, bmdFrameFlagDefault, &m_videoFrameBlack) != S_OK)
// 	{
// 		fprintf(stderr, "Failed to create video frame\n");	
// 		goto bail;
// 	}
// 	FillBlack(m_videoFrameBlack);
// 	
// 	// Generate a frame of colour bars
// 	if (m_deckLinkOutput->CreateVideoFrame(m_frameWidth, m_frameHeight, m_frameWidth*2, bmdFormat8BitYUV, bmdFrameFlagDefault, &m_videoFrameBars) != S_OK)
// 	{
// 		fprintf(stderr, "Failed to create video frame\n");
// 		goto bail;
// 	}
// 	FillColourBars(m_videoFrameBars);
	
	
	// Begin video preroll by scheduling a second of frames in hardware
	m_totalFramesScheduled = 0;
  	for (unsigned i = 0; i < m_framesPerSecond; i++)
  	{
  		PrepareFrame();
 		ScheduleNextFrame(true);
 	}
	
	// Args: startTime, timeScale, playback speed (1.0 = normal)
	m_deckLinkOutput->StartScheduledPlayback(0, 100, 1.0);
	
	m_running = true;
	
	return;
	
bail:
	// *** Error-handling code.  Cleanup any resources that were allocated. *** //
	StopRunning();
}

	HRESULT render( mlt_frame frame )
	{
		HRESULT result = S_OK;
		// Get the audio		
		double speed = mlt_properties_get_double( MLT_FRAME_PROPERTIES(frame), "_speed" );
		if ( speed == 1.0 )
		{
			mlt_audio_format format = mlt_audio_s16;
			int frequency = bmdAudioSampleRate48kHz;
			int samples = mlt_sample_calculator( m_fps, frequency, m_count );
			int16_t *pcm = 0;
			
			if ( !mlt_frame_get_audio( frame, (void**) &pcm, &format, &frequency, &m_channels, &samples ) )
			{
				int count = samples;
				
				if ( !m_isPrerolling )
				{
					uint32_t audioCount = 0;
					uint32_t videoCount = 0;
					
					// Check for resync
					m_deckLinkOutput->GetBufferedAudioSampleFrameCount( &audioCount );
					m_deckLinkOutput->GetBufferedVideoFrameCount( &videoCount );
					
					// Underflow typically occurs during non-normal speed playback.
					if ( audioCount < 1 || videoCount < 1 )
					{
						// Upon switching to normal playback, buffer some frames faster than realtime.
						mlt_log_info( &m_consumer, "buffer underrun: audio buf %u video buf %u frames\n", audioCount, videoCount );
						m_prerollCounter = 0;
					}
					
					// While rebuffering
					if ( isBuffering() )
					{
						// Only append audio to reach the ideal level and not overbuffer.
						int ideal = ( m_preroll - 1 ) * bmdAudioSampleRate48kHz / m_fps;
						int actual = m_fifo->used / m_channels + audioCount;
						int diff = ideal / 2 - actual;
						count = diff < 0 ? 0 : diff < count ? diff : count;
					}
				}
				if ( count > 0 )
					sample_fifo_append( m_fifo, pcm, count * m_channels );
			}
		}
		
		// Create video frames while pre-rolling
		if ( m_isPrerolling )
		{
			createFrame();
			if ( !m_videoFrame )
			{
				mlt_log_error( &m_consumer, "failed to create video frame\n" );
				return S_FALSE;
			}
		}
		
		// Get the video
		if ( mlt_properties_get_int( MLT_FRAME_PROPERTIES( frame ), "rendered") )
		{
			mlt_image_format format = mlt_image_yuv422;
			uint8_t* image = 0;
			uint8_t* buffer = 0;

			if ( !mlt_frame_get_image( frame, &image, &format, &m_width, &m_height, 0 ) )
			{
				m_videoFrame = (IDeckLinkMutableVideoFrame*) mlt_deque_pop_back( m_videoFrameQ );
				m_videoFrame->GetBytes( (void**) &buffer );
				if ( m_displayMode->GetFieldDominance() == bmdUpperFieldFirst )
					// convert lower field first to top field first
					swab( image, buffer + m_width * 2, m_width * ( m_height - 1 ) * 2 );
				else
					swab( image, buffer, m_width * m_height * 2 );
				m_deckLinkOutput->ScheduleVideoFrame( m_videoFrame, m_count * m_duration, m_duration, m_timescale );
				mlt_deque_push_front( m_videoFrameQ, m_videoFrame );
			}
		}
		else
		{
			mlt_log_verbose( &m_consumer, "dropped video frame\n" );
		}
		++m_count;

		// Check for end of pre-roll
		if ( ++m_prerollCounter > m_preroll && m_isPrerolling )
		{
			// Start audio and video output
			m_deckLinkOutput->EndAudioPreroll();
			m_deckLinkOutput->StartScheduledPlayback( 0, m_timescale, 1.0 );
			m_isPrerolling = false;
		}

		return result;
	}