Add temporally overlapping subtitle support.

* New subtitle sync algorithm added to sync work-object ("simultaneous").
  Classic algorithm preserved but disabled.
* Render work-object now supports queueing a /list/ of subtitles.
* FIFOs have been extended to support pushing/popping buffer-lists as single elements.
* Added SUBSYNC_VERBOSE_TIMING flag to debug timing issues related to subtitle display.

Observable behaviors changed in the new subtitle sync algorithm:
* Temporally overlapping subtitles are no longer trimmed to be non-overlapping.
* Subtitles less than two seconds long are no longer artificially extended. Sorry, Indochine fans.
* Subtitles that stop before they start will never be displayed. The old algorithm will display such subtitles if they begin in the future (relative to the current video frame being processed).



git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@3804 b64f7644-9d1e-0410-96f1-a4d463321fa5

1 files changed, 47 insertions, 16 deletions

diff --git a/libhb/render.c b/libhb/render.c
index 8c7e9a2d8..c16b9403d 100644
--- a/libhb/render.c
+++ b/libhb/render.c
@@ -67,6 +67,8 @@ static uint8_t *getV(uint8_t *data, int width, int height, int x, int y)
     return(&data[(y>>1) * w2 + (x>>1) + width*height + w2*h2]);
 }
 
+// Draws the specified PICTURESUB subtitle on the specified video packet.
+// Disposes the subtitle afterwards.
 static void ApplySub( hb_job_t * job, hb_buffer_t * buf,
                       hb_buffer_t ** _sub )
 {
@@ -397,11 +399,11 @@ int renderWork( hb_work_object_t * w, hb_buffer_t ** buf_in,
     /* Push subtitles onto queue just in case we need to delay a frame */
     if( in->sub )
     {
-        hb_fifo_push( pv->subtitle_queue, in->sub );
+        hb_fifo_push_list_element( pv->subtitle_queue, in->sub );
     }
     else
     {
-        hb_fifo_push( pv->subtitle_queue,  hb_buffer_init(0) );
+        hb_fifo_push_list_element( pv->subtitle_queue, NULL );
     }
 
     /* If there's a chapter mark remember it in case we delay or drop its frame */
@@ -451,11 +453,15 @@ int renderWork( hb_work_object_t * w, hb_buffer_t ** buf_in,
             }
             else if( result == FILTER_DELAY )
             {
+                // Process the current frame later
+                
                 buf_tmp_in = NULL;
                 break;
             }
             else if( result == FILTER_DROP )
             {
+                // Drop the current frame
+                
                 /* We need to compensate for the time lost by dropping this frame.
                    Spread its duration out in quarters, because usually dropped frames
                    maintain a 1-out-of-5 pattern and this spreads it out amongst the remaining ones.
@@ -471,15 +477,28 @@ int renderWork( hb_work_object_t * w, hb_buffer_t ** buf_in,
                 pv->total_lost_time += temp_duration;
                 pv->dropped_frames++;
 
-                /* Pop the frame's subtitle and dispose of it. */
-                hb_buffer_t * subpicture_list = hb_fifo_get( pv->subtitle_queue );
-                hb_buffer_t * subpicture;
-                hb_buffer_t * subpicture_next;
-                for ( subpicture = subpicture_list; subpicture; subpicture = subpicture_next )
+                /* Pop the frame's subtitle list and dispose of it. */
+                hb_buffer_t * sub_list = hb_fifo_get_list_element( pv->subtitle_queue );
+                hb_buffer_t * sub;
+                hb_buffer_t * sub_next;
+                for ( sub = sub_list; sub; sub = sub_next )
                 {
-                    subpicture_next = subpicture->next_subpicture;
-                    hb_buffer_close( &subpicture );
+                    sub_next = sub->next;
+                    // XXX: Prevent hb_buffer_close from killing the whole list
+                    //      before we finish iterating over it
+                    sub->next = NULL;
+                    
+                    hb_buffer_t * subpicture_list = sub;
+                    hb_buffer_t * subpicture;
+                    hb_buffer_t * subpicture_next;
+                    for ( subpicture = subpicture_list; subpicture; subpicture = subpicture_next )
+                    {
+                        subpicture_next = subpicture->next_subpicture;
+                        
+                        hb_buffer_close( &subpicture );
+                    }
                 }
+                
                 buf_tmp_in = NULL;
                 break;
             }
@@ -503,16 +522,28 @@ int renderWork( hb_work_object_t * w, hb_buffer_t ** buf_in,
         pv->last_stop[0] = pv->last_start[0] + (buf_tmp_in->stop - buf_tmp_in->start);
     }
 
-    /* Apply subtitles */
+    /* Apply subtitles and dispose them */
     if( buf_tmp_in )
     {
-        hb_buffer_t * subpicture_list = hb_fifo_get( pv->subtitle_queue );
-        hb_buffer_t * subpicture;
-        hb_buffer_t * subpicture_next;
-        for ( subpicture = subpicture_list; subpicture; subpicture = subpicture_next )
+        hb_buffer_t * sub_list = hb_fifo_get_list_element( pv->subtitle_queue );
+        hb_buffer_t * sub;
+        hb_buffer_t * sub_next;
+        for ( sub = sub_list; sub; sub = sub_next )
         {
-            subpicture_next = subpicture->next_subpicture;
-            ApplySub( job, buf_tmp_in, &subpicture );
+            sub_next = sub->next;
+            // XXX: Prevent hb_buffer_close inside ApplySub from killing the whole list
+            //      before we finish iterating over it
+            sub->next = NULL;
+            
+            hb_buffer_t * subpicture_list = sub;
+            hb_buffer_t * subpicture;
+            hb_buffer_t * subpicture_next;
+            for ( subpicture = subpicture_list; subpicture; subpicture = subpicture_next )
+            {
+                subpicture_next = subpicture->next_subpicture;
+                
+                ApplySub( job, buf_tmp_in, &subpicture );
+            }
         }
     }