static inline int first_unprocessed_frame( mlt_consumer self )
{
int index = self->real_time <= 0 ? 0 : self->process_head;
while ( index < mlt_deque_count( self->queue ) && MLT_FRAME( mlt_deque_peek( self->queue, index ) )->is_processing )
index++;
return index;
}
void consumer_purge( mlt_consumer parent )
{
consumer_sdl self = parent->child;
if ( self->running )
{
pthread_mutex_lock( &self->video_mutex );
mlt_frame frame = MLT_FRAME( mlt_deque_peek_back( self->queue ) );
// When playing rewind or fast forward then we need to keep one
// frame in the queue to prevent playback stalling.
double speed = frame? mlt_properties_get_double( MLT_FRAME_PROPERTIES(frame), "_speed" ) : 0;
int n = ( speed == 0.0 || speed == 1.0 ) ? 0 : 1;
while ( mlt_deque_count( self->queue ) > n )
mlt_frame_close( mlt_deque_pop_back( self->queue ) );
self->is_purge = 1;
pthread_cond_broadcast( &self->video_cond );
pthread_mutex_unlock( &self->video_mutex );
}
}
static mlt_frame worker_get_frame( mlt_consumer self, mlt_properties properties )
{
// Frame to return
mlt_frame frame = NULL;
double fps = mlt_properties_get_double( properties, "fps" );
int threads = abs( self->real_time );
int buffer = mlt_properties_get_int( properties, "_buffer" );
buffer = buffer > 0 ? buffer : mlt_properties_get_int( properties, "buffer" );
// This is a heuristic to determine a suitable minimum buffer size for the number of threads.
int headroom = 2 + threads * threads;
buffer = buffer < headroom ? headroom : buffer;
// Start worker threads if not already started.
if ( ! self->ahead )
{
int prefill = mlt_properties_get_int( properties, "prefill" );
prefill = prefill > 0 && prefill < buffer ? prefill : buffer;
consumer_work_start( self );
// Fill the work queue.
int i = buffer;
while ( self->ahead && i-- )
{
frame = mlt_consumer_get_frame( self );
if ( frame )
{
pthread_mutex_lock( &self->queue_mutex );
mlt_deque_push_back( self->queue, frame );
pthread_cond_signal( &self->queue_cond );
pthread_mutex_unlock( &self->queue_mutex );
}
}
// Wait for prefill
while ( self->ahead && first_unprocessed_frame( self ) < prefill )
{
pthread_mutex_lock( &self->done_mutex );
pthread_cond_wait( &self->done_cond, &self->done_mutex );
pthread_mutex_unlock( &self->done_mutex );
}
self->process_head = threads;
}
// mlt_log_verbose( MLT_CONSUMER_SERVICE(self), "size %d done count %d work count %d process_head %d\n",
// threads, first_unprocessed_frame( self ), mlt_deque_count( self->queue ), self->process_head );
// Feed the work queue
while ( self->ahead && mlt_deque_count( self->queue ) < buffer )
{
frame = mlt_consumer_get_frame( self );
if ( ! frame )
return frame;
pthread_mutex_lock( &self->queue_mutex );
mlt_deque_push_back( self->queue, frame );
pthread_cond_signal( &self->queue_cond );
pthread_mutex_unlock( &self->queue_mutex );
}
// Wait if not realtime.
mlt_frame head_frame = MLT_FRAME( mlt_deque_peek_front( self->queue ) );
while ( self->ahead && self->real_time < 0 &&
!( head_frame && mlt_properties_get_int( MLT_FRAME_PROPERTIES( head_frame ), "rendered" ) ) )
{
pthread_mutex_lock( &self->done_mutex );
pthread_cond_wait( &self->done_cond, &self->done_mutex );
pthread_mutex_unlock( &self->done_mutex );
}
// Get the frame from the queue.
pthread_mutex_lock( &self->queue_mutex );
frame = mlt_deque_pop_front( self->queue );
pthread_mutex_unlock( &self->queue_mutex );
// Adapt the worker process head to the runtime conditions.
if ( self->real_time > 0 )
{
if ( frame && mlt_properties_get_int( MLT_FRAME_PROPERTIES( frame ), "rendered" ) )
{
self->consecutive_dropped = 0;
if ( self->process_head > threads && self->consecutive_rendered >= self->process_head )
self->process_head--;
else
self->consecutive_rendered++;
}
else
{
self->consecutive_rendered = 0;
if ( self->process_head < buffer - threads && self->consecutive_dropped > threads )
self->process_head++;
else
self->consecutive_dropped++;
}
// mlt_log_verbose( MLT_CONSUMER_SERVICE(self), "dropped %d rendered %d process_head %d\n",
// self->consecutive_dropped, self->consecutive_rendered, self->process_head );
// Check for too many consecutively dropped frames
if ( self->consecutive_dropped > mlt_properties_get_int( properties, "drop_max" ) )
{
int orig_buffer = mlt_properties_get_int( properties, "buffer" );
int prefill = mlt_properties_get_int( properties, "prefill" );
mlt_log_verbose( self, "too many frames dropped - " );
// If using a default low-latency buffer level (SDL) and below the limit
if ( ( orig_buffer == 1 || prefill == 1 ) && buffer < (threads + 1) * 10 )
{
// Auto-scale the buffer to compensate
mlt_log_verbose( self, "increasing buffer to %d\n", buffer + threads );
mlt_properties_set_int( properties, "_buffer", buffer + threads );
self->consecutive_dropped = fps / 2;
}
else
{
// Tell the consumer to render it
mlt_log_verbose( self, "forcing next frame\n" );
mlt_properties_set_int( MLT_FRAME_PROPERTIES( frame ), "rendered", 1 );
self->consecutive_dropped = 0;
}
}
}
return frame;
}