Simplify and comment real_time=1 frame-dropping.

diff --git a/src/framework/mlt_consumer.c b/src/framework/mlt_consumer.c
index 02deff3cac4e0b3a465bc69e3f1f099262e32fb7..9794b82620870f2a99d867156d3242ad77c2511a 100644 (file)
--- a/src/framework/mlt_consumer.c
+++ b/src/framework/mlt_consumer.c
@@ -638,10 +638,8 @@ static void *consumer_read_ahead_thread( void *arg )
        struct timeval ante;
 
        // Average time for get_frame and get_image
-       int count = 1;
+       int count = 0;
        int skipped = 0;
-       int64_t time_wait = 0;
-       int64_t time_frame = 0;
        int64_t time_process = 0;
        int skip_next = 0;
        mlt_position pos = 0;
@@ -680,10 +678,6 @@ static void *consumer_read_ahead_thread( void *arg )
        // Continue to read ahead
        while ( self->ahead )
        {
-               // Fetch width/height again
-               width = mlt_properties_get_int( properties, "width" );
-               height = mlt_properties_get_int( properties, "height" );
-
                // Put the current frame into the queue
                pthread_mutex_lock( &self->queue_mutex );
                while( self->ahead && mlt_deque_count( self->queue ) >= buffer )
@@ -692,61 +686,59 @@ static void *consumer_read_ahead_thread( void *arg )
                pthread_cond_broadcast( &self->queue_cond );
                pthread_mutex_unlock( &self->queue_mutex );
 
-               time_wait += time_difference( &ante );
-
                // Get the next frame
                frame = mlt_consumer_get_frame( self );
-               time_frame += time_difference( &ante );
 
                // If there's no frame, we're probably stopped...
                if ( frame == NULL )
                        continue;
                pos = mlt_frame_get_position( frame );
 
-               // Increment the count
+               // Increment the counter used for averaging processing cost
                count ++;
 
-               // All non normal playback frames should be shown
+               // All non-normal playback frames should be shown
                if ( mlt_properties_get_int( MLT_FRAME_PROPERTIES( frame ), "_speed" ) != 1 )
                {
 #ifdef DEINTERLACE_ON_NOT_NORMAL_SPEED
                        mlt_properties_set_int( MLT_FRAME_PROPERTIES( frame ), "consumer_deinterlace", 1 );
 #endif
-                       skipped = 0;
-                       time_frame = 0;
-                       time_process = 0;
-                       time_wait = 0;
-                       count = 1;
-                       skip_next = 0;
+                       // Indicate seeking or trick-play
                        start_pos = pos;
                }
 
-               // Get the image
+               // If skip flag not set or frame-dropping disabled
                if ( !skip_next || self->real_time == -1 )
                {
-                       // Get the image, mark as rendered and time it
                        if ( !video_off )
                        {
+                               // Reset width/height - could have been changed by previous mlt_frame_get_image
+                               width = mlt_properties_get_int( properties, "width" );
+                               height = mlt_properties_get_int( properties, "height" );
+
+                               // Get the image
                                mlt_events_fire( MLT_CONSUMER_PROPERTIES( self ), "consumer-frame-render", frame, NULL );
                                mlt_frame_get_image( frame, &image, &self->format, &width, &height, 0 );
                        }
+
+                       // Indicate the rendered image is available.
                        mlt_properties_set_int( MLT_FRAME_PROPERTIES( frame ), "rendered", 1 );
+
+                       // Reset consecutively-skipped counter
                        skipped = 0;
                }
-               else
+               else // Skip image processing
                {
-                       // Increment the number of sequentially skipped frames
-                       skipped ++;
-                       skip_next = 0;
+                       // Increment the number of consecutively-skipped frames
+                       skipped++;
 
-                       // If we've reached an unacceptable level, reset everything
-                       if ( skipped > fps * 2 )
+                       // If too many (1 sec) consecutively-skipped frames
+                       if ( skipped > fps )
                        {
-                               skipped = 0;
-                               time_frame = 0;
+                               // Reset cost tracker
                                time_process = 0;
-                               time_wait = 0;
                                count = 1;
+                               mlt_log_verbose( self, "too many frames dropped - forcing next frame\n" );
                        }
                }
 
@@ -757,27 +749,35 @@ static void *consumer_read_ahead_thread( void *arg )
                        mlt_frame_get_audio( frame, &audio, &afmt, &frequency, &channels, &samples );
                }
 
-               // Increment the time take for self frame
+               // Accumulate the cost for processing this frame
                time_process += time_difference( &ante );
 
-               // Determine if the next frame should be skipped
+               // Determine if we started, resumed, or seeked
                if ( pos != last_pos + 1 )
                        start_pos = pos;
                last_pos = pos;
+
+               // Do not skip the first 20% of buffer at start, resume, or seek
                if ( pos - start_pos <= buffer/5 )
                {
-                       // Do not skip the first 20% of buffer at start, resuming, or seeking
-                       skipped = 0;
-                       time_frame = 0;
+                       // Reset cost tracker
                        time_process = 0;
-                       time_wait = 0;
                        count = 1;
                }
+
+               // Reset skip flag
+               skip_next = 0;
+
+               // Only consider skipping if the buffer level is low (or really small)
                if ( mlt_deque_count( self->queue ) <= buffer/5 )
                {
+                       // Skip next frame if average cost exceeds frame duration.
                        int frame_duration = mlt_properties_get_int( properties, "frame_duration" );
-                       if ( ( ( time_wait + time_frame + time_process ) / count ) > frame_duration )
+                       if ( time_process / count > frame_duration )
                                skip_next = 1;
+                       if ( skip_next )
+                               mlt_log_debug( self, "avg usec %"PRId64" (%"PRId64"/%d) duration %d\n",
+                                       time_process/count, time_process, count, frame_duration);
                }
        }