From: Marco Paniconi <marpan@google.com>
Date: Mon, 26 Nov 2018 23:52:21 +0000 (-0800)
Subject: vp9-svc: Put check on usage of long term temporal ref.
X-Git-Tag: v1.8.0~129
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=0aaf170c13e408a8c2be2e0275538744dde30249;p=libvpx

vp9-svc: Put check on usage of long term temporal ref.

If the scale factor of the golden long term reference
is different from the last reference then disable usage
of long term reference.

This should not happen, but add this as a check against
some possibly incorrect update of the svc configuration.

Change-Id: Ic1062d4384e005007d8c922813fa8ad188d8fa98
---

diff --git a/vp9/encoder/vp9_pickmode.c b/vp9/encoder/vp9_pickmode.c
index 8dce4cf7b..1324b5bc8 100644
--- a/vp9/encoder/vp9_pickmode.c
+++ b/vp9/encoder/vp9_pickmode.c
@@ -1732,11 +1732,21 @@ void vp9_pick_inter_mode(VP9_COMP *cpi, MACROBLOCK *x, TileDataEnc *tile_data,
   if (!cpi->use_svc ||
       (svc->use_gf_temporal_ref_current_layer &&
        !svc->layer_context[svc->temporal_layer_id].is_key_frame)) {
+    struct scale_factors *const sf_last = &cm->frame_refs[LAST_FRAME - 1].sf;
+    struct scale_factors *const sf_golden =
+        &cm->frame_refs[GOLDEN_FRAME - 1].sf;
     gf_temporal_ref = 1;
-    if (cpi->rc.avg_frame_low_motion > 70)
-      thresh_svc_skip_golden = 500;
-    else
-      thresh_svc_skip_golden = 0;
+    // For temporal long term prediction, check that the golden reference
+    // is same scale as last reference, otherwise disable.
+    if ((sf_last->x_scale_fp != sf_golden->x_scale_fp) ||
+        (sf_last->y_scale_fp != sf_golden->y_scale_fp)) {
+      gf_temporal_ref = 0;
+    } else {
+      if (cpi->rc.avg_frame_low_motion > 70)
+        thresh_svc_skip_golden = 500;
+      else
+        thresh_svc_skip_golden = 0;
+    }
   }
 
   init_ref_frame_cost(cm, xd, ref_frame_cost);