Index: libhb/render.c
===================================================================
--- libhb/render.c	(revision 1047)
+++ libhb/render.c	(working copy)
@@ -19,6 +19,8 @@
     AVPicture            pic_tmp_out;        
     hb_buffer_t        * buf_scale;
     hb_fifo_t          * subtitle_queue;
+    hb_fifo_t          * delay_queue;
+    int                  ivtc_frames;
 };
 
 int  renderInit( hb_work_object_t *, hb_job_t * );
@@ -153,10 +155,14 @@
     hb_job_t   * job   = pv->job;
     hb_title_t * title = job->title;
     hb_buffer_t * in = *buf_in, * buf_tmp_in = *buf_in;
+    hb_buffer_t * ivtc_buffer = NULL;
     
     if(!in->data)
     {
-        /* If the input buffer is end of stream, send out an empty one to the next stage as well. */
+        /* If the input buffer is end of stream, send out an empty one
+         * to the next stage as well. Note that this will result in us
+         * losing the current contents of the delay queue.
+         */
        *buf_out = hb_buffer_init(0);
        return HB_WORK_OK;
     }
@@ -227,6 +233,10 @@
             {
                 hb_fifo_get( pv->subtitle_queue );
                 buf_tmp_in = NULL;
+                if( job->vfr )
+                {
+                    pv->ivtc_frames = 3;
+                }
                 break;
             }
         }
@@ -292,6 +302,64 @@
         hb_buffer_copy_settings( buf_render, buf_tmp_in );
     }
 
+    if( pv->ivtc_frames == 3 )
+    {
+        /*
+         * We have just detected a dropped frame and variable frame rate 
+         * is enabled. We need to rewrite the times on the last two
+         * buffers, and also the next two to arrive.
+         */
+        
+        ivtc_buffer = hb_fifo_see2( pv->delay_queue );
+        
+        if( ivtc_buffer )
+        {
+            /*
+             * This is the buffer from 2 frames ago, rewrite the duration on it.
+             */
+            ivtc_buffer->stop = ivtc_buffer->stop + (90090000 / 120000);
+        }
+        
+        ivtc_buffer = hb_fifo_see( pv->delay_queue );
+        
+        if( ivtc_buffer )
+        {
+            /*
+             * This is the buffer from 1 frame ago, rewrite the duration on it.
+             */
+            ivtc_buffer->stop = ivtc_buffer->stop + (90090000 / 120000);
+        }
+
+        /*
+         * Process the next 2 frames to arrive as well.
+         */
+        pv->ivtc_frames = 2;
+    }
+
+    if( *buf_out )
+    {
+        if( pv->ivtc_frames )
+        {
+            /*
+             * This is an ivtc frame, rewrite the duration on it.
+             */
+            ivtc_buffer = *buf_out;
+            ivtc_buffer->stop = ivtc_buffer->stop + (90090000 / 120000);
+            pv->ivtc_frames--;
+        }
+        hb_fifo_push( pv->delay_queue, *buf_out );
+        *buf_out = NULL;
+    }
+
+    /*
+     * Keep the last three frames in our queue, this ensures that we have the last
+     * two always in there should we need to rewrite the durations on them.
+     */
+    if( hb_fifo_size( pv->delay_queue ) >= 3 )
+    {
+        *buf_out = hb_fifo_get( pv->delay_queue );
+    } 
+
     return HB_WORK_OK;
 }
 
@@ -304,7 +372,12 @@
     {
         hb_fifo_close( &pv->subtitle_queue );
     }
-    
+
+    if( pv->delay_queue )
+    {
+        hb_fifo_close( &pv->delay_queue );
+    }
+   
     /* Cleanup filters */
     /* TODO: Move to work.c? */
     if( pv->job->filters )
@@ -351,7 +424,9 @@
     }   
     
     /* Setup FIFO queue for subtitle cache */
-    pv->subtitle_queue = hb_fifo_init( 8 );    
+    pv->subtitle_queue = hb_fifo_init( 8 );
+    pv->delay_queue = hb_fifo_init( 8 );
+    pv->ivtc_frames = 0;
     
     /* Setup filters */
     /* TODO: Move to work.c? */
Index: libhb/common.h
===================================================================
--- libhb/common.h	(revision 1047)
+++ libhb/common.h	(working copy)
@@ -172,6 +172,7 @@
     int             crf;
     char            *x264opts;
     int             areBframes;
+    int             vfr;
     
     /* Audio tracks:
          audios:          Indexes in hb_title_t's audios list, starting from 0.