vo: avoid overshooting the expected end of the frame during pause

The `current_frame` can be redrawn even if the remaining `num_vsync` is
equal to 0. In this scenario, the vsync offset would be incremented
beyond the target point.

1 files changed, 7 insertions, 2 deletions

diff --git a/video/out/vo.c b/video/out/vo.c
index 8027763eab..50129fb306 100644
--- a/video/out/vo.c
+++ b/video/out/vo.c
@@ -898,8 +898,13 @@ static bool render_frame(struct vo *vo)
     // frame currently drawn, while in->current_frame is the potentially next.)
     in->current_frame->repeat = true;
     if (frame->display_synced) {
-        in->current_frame->vsync_offset += in->current_frame->vsync_interval;
-        in->current_frame->ideal_frame_vsync += in->current_frame->ideal_frame_vsync_duration;
+        // Increment the offset only if it's not the last vsync. The current_frame
+        // can still be reused. This is mostly important for redraws that might
+        // overshoot the target vsync point.
+        if (in->current_frame->num_vsyncs > 1) {
+            in->current_frame->vsync_offset += in->current_frame->vsync_interval;
+            in->current_frame->ideal_frame_vsync += in->current_frame->ideal_frame_vsync_duration;
+        }
         in->dropped_frame |= in->current_frame->num_vsyncs < 1;
     }
     if (in->current_frame->num_vsyncs > 0)