/*
* Try sending some audio data to the Decklink.
* Call only with current_audio_pkt != NULL.
* Will set current_audio_pkt to NULL and delete the packet
* if it is fully consumed.
* Return number of samples consumed.
*/
int try_finish_current_audio_packet( ) {
uint32_t n_consumed;
uint32_t n_left;
uint32_t buffer;
deckLinkOutput->GetBufferedAudioSampleFrameCount(&buffer);
fprintf(stderr, "audio buffer = %u ", buffer);
assert(current_audio_pkt != NULL);
n_left = current_audio_pkt->n_frames( )
- samples_written_from_current_audio_pkt;
if (n_left == 0) {
fprintf(stderr, "Audio warning: This should not happen!\n");
return 1;
}
if (deckLinkOutput->ScheduleAudioSamples(
current_audio_pkt->sample(
samples_written_from_current_audio_pkt
), n_left, 0, 0, &n_consumed) != S_OK) {
throw std::runtime_error(
"Failed to schedule audio samples"
);
}
if (n_consumed == n_left) {
delete current_audio_pkt;
current_audio_pkt = NULL;
} else if (n_consumed < n_left) {
samples_written_from_current_audio_pkt += n_consumed;
} else {
throw std::runtime_error("This should not happen");
}
deckLinkOutput->GetBufferedAudioSampleFrameCount(&buffer);
fprintf(stderr, "-> %u\n", buffer);
return n_consumed;
}
virtual HRESULT STDMETHODCALLTYPE RenderAudioSamples( bool preroll )
{
// Provide more audio samples to the DeckLink API
HRESULT result = S_OK;
uint32_t count = m_fifo->used / m_channels;
uint32_t buffered = count;
if ( count
// Stay under preferred buffer level
&& ( S_OK == m_deckLinkOutput->GetBufferedAudioSampleFrameCount( &buffered ) )
&& buffered < m_maxAudioBuffer )
{
uint32_t written = 0;
buffered = m_maxAudioBuffer - buffered;
count = buffered > count ? count : buffered;
result = m_deckLinkOutput->ScheduleAudioSamples( m_fifo->buffer, count, 0, 0, &written );
if ( written )
sample_fifo_remove( m_fifo, written * m_channels );
}
return result;
}
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;
}