Avoid immediate frame drops by giving decoder a further chance to

supply decoded frames.
There can still be scheduling delays which may let the number of
frames ready for displaying to drop below frame drop limit just
for a short period of time.
Therefore the changes remember that the decoder should have been
asked to drop some frames but do not actually have the decoder to
drop some frames. When the situation has improved at the next time
when the check is performed, the remembered frame drop is canceled
or otherwise (when the number of frames is still below frame drop
limit) executed.

1 files changed, 17 insertions, 0 deletions

diff --git a/src/xine-engine/video_out.c b/src/xine-engine/video_out.c
index c75b7058a..6177cbef8 100644
--- a/src/xine-engine/video_out.c
+++ b/src/xine-engine/video_out.c
@@ -132,6 +132,7 @@ typedef struct {
   int                       frame_drop_limit_max;
   int                       frame_drop_limit;
   int                       frame_drop_cpt;
+  int                       frame_drop_suggested;
   int                       crop_left, crop_right, crop_top, crop_bottom;
 } vos_t;
 
@@ -499,6 +500,21 @@ static int vo_frame_draw (vo_frame_t *img, xine_stream_t *stream) {
         frames_to_skip < 0)
       frames_to_skip = 0;
       
+    /* Do not drop frames immediately, but remember this as suggestion and give
+     * decoder a further chance to supply frames.
+     * This avoids unnecessary frame drops in situations where there is only
+     * a very little number of image buffers, e. g. when using xxmc.
+     */
+    if (this->frame_drop_suggested && frames_to_skip == 0)
+      this->frame_drop_suggested = 0;
+
+    if (frames_to_skip > 0) {
+      if (!this->frame_drop_suggested) {
+        this->frame_drop_suggested = 1;
+        frames_to_skip = 0;
+      }
+    }
+
     lprintf ("delivery diff : %" PRId64 ", current vpts is %" PRId64 ", %d frames to skip\n",
 	     diff, cur_vpts, frames_to_skip);
     
@@ -1872,6 +1888,7 @@ xine_video_port_t *_x_vo_new_port (xine_t *xine, vo_driver_t *driver, int grabon
 
   this->frame_drop_limit      = this->frame_drop_limit_max;
   this->frame_drop_cpt        = 0;
+  this->frame_drop_suggested  = 0;
 
   this->extra_info_base = calloc (num_frame_buffers,
 					  sizeof(extra_info_t));