Avoid skipping an unsuitable frame when there are only few buffers

available.
Usually it's a good idea to avoid reallocating frames especially
when a deinterlacer needs a different format than the decoder, as
this would then happen all the time.
But when there is only a limited number of frames available, then
even a single frame which is not scheduled at frame allocation may
let the number of frames ready for displaying drop below frame
drop limit and thus resulting in unnecessary frame drops.
(transplanted from 235058555243755d3aebff03d898f1a5b94ff95e)

--HG--
extra : transplant_source : %23PXURCu%5D%3A%EB%FF%03%D8%98%F1%A5%B9O%F9%5E

1 files changed, 12 insertions, 6 deletions

diff --git a/src/xine-engine/video_out.c b/src/xine-engine/video_out.c
index a5fd544d0..f0664210e 100644
--- a/src/xine-engine/video_out.c
+++ b/src/xine-engine/video_out.c
@@ -69,6 +69,7 @@ typedef struct {
   vo_frame_t        *first;
   vo_frame_t        *last;
   int                num_buffers;
+  int                num_buffers_max;
 
   int                locked_for_read;
   pthread_mutex_t    mutex;
@@ -142,9 +143,11 @@ static img_buf_fifo_t *vo_new_img_buf_queue () {
 
   queue = (img_buf_fifo_t *) xine_xmalloc (sizeof (img_buf_fifo_t));
   if( queue ) {
-    queue->first       = NULL;
-    queue->last        = NULL;
-    queue->num_buffers = 0;
+    queue->first           = NULL;
+    queue->last            = NULL;
+    queue->num_buffers     = 0;
+    queue->num_buffers_max = 0;
+
     queue->locked_for_read = 0;
     pthread_mutex_init (&queue->mutex, NULL);
     pthread_cond_init  (&queue->not_empty, NULL);
@@ -171,6 +174,8 @@ static void vo_append_to_img_buf_queue_int (img_buf_fifo_t *queue,
   }
 
   queue->num_buffers++;
+  if (queue->num_buffers_max < queue->num_buffers)
+    queue->num_buffers_max = queue->num_buffers;
 
   pthread_cond_signal (&queue->not_empty);
 }
@@ -211,14 +216,15 @@ static vo_frame_t *vo_remove_from_img_buf_queue_int (img_buf_fifo_t *queue, int
       
       if( width && height ) {
         if( !img ) {
-          if( queue->num_buffers == 1 && !blocking) {
+          if( queue->num_buffers == 1 && !blocking && queue->num_buffers_max > 8) {
             /* non-blocking and only a single frame on fifo with different
              * format -> ignore it (give another chance of a frame format hit)
+             * only if we have a lot of buffers at all.
              */
             lprintf("frame format mismatch - will wait another frame\n");
           } else {
-            /* we have at least 2 frames on fifo but they don't match ->
-             * give up. return whatever we got.
+            /* we have just a limited number of buffers or at least 2 frames
+             * on fifo but they don't match -> give up. return whatever we got.
              */
             img = queue->first;
             lprintf("frame format miss (%d/%d)\n", i, queue->num_buffers);