From: Marco Paniconi <marpan@google.com>
Date: Tue, 8 May 2018 18:05:03 +0000 (-0700)
Subject: vp9-svc: Fix to SVC for frame dropping.
X-Git-Tag: v1.8.0~706^2
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=bb06546d56a82a4953666dfae91d52881e896075;p=libvpx

vp9-svc: Fix to SVC for frame dropping.

When the previous frame is dropped, for the current
spatial layer make sure the lst_fb_idx corresponds
to the buffer index last updated on the (last) encoded
TL0 frame(for same spatial layer).

This is needed to preserve the temporal prediction pattern
for fixed/non-flexible mode under frame dropping.

Change-Id: Ifc8e257beb025654a81580c4da0a181235724508
---

diff --git a/vp9/encoder/vp9_encoder.c b/vp9/encoder/vp9_encoder.c
index 9ae5dc03d..3384de7ea 100644
--- a/vp9/encoder/vp9_encoder.c
+++ b/vp9/encoder/vp9_encoder.c
@@ -4593,6 +4593,16 @@ static void encode_frame_to_data_rate(VP9_COMP *cpi, size_t *size,
 
   cpi->last_frame_dropped = 0;
   cpi->svc.last_layer_dropped[cpi->svc.spatial_layer_id] = 0;
+  // Keep track of the frame buffer index updated/refreshed for the
+  // current encoded TL0 superframe.
+  if (cpi->svc.temporal_layer_id == 0) {
+    if (cpi->refresh_last_frame)
+      cpi->svc.fb_idx_upd_tl0[cpi->svc.spatial_layer_id] = cpi->lst_fb_idx;
+    else if (cpi->refresh_golden_frame)
+      cpi->svc.fb_idx_upd_tl0[cpi->svc.spatial_layer_id] = cpi->gld_fb_idx;
+    else if (cpi->refresh_alt_ref_frame)
+      cpi->svc.fb_idx_upd_tl0[cpi->svc.spatial_layer_id] = cpi->alt_fb_idx;
+  }
 
   // Disable segmentation if it decrease rate/distortion ratio
   if (cpi->oxcf.aq_mode == LOOKAHEAD_AQ)
diff --git a/vp9/encoder/vp9_svc_layercontext.c b/vp9/encoder/vp9_svc_layercontext.c
index 84e47c6be..07d1995a8 100644
--- a/vp9/encoder/vp9_svc_layercontext.c
+++ b/vp9/encoder/vp9_svc_layercontext.c
@@ -786,6 +786,15 @@ int vp9_one_pass_cbr_svc_start_layer(VP9_COMP *const cpi) {
 
   if (cpi->svc.spatial_layer_id == 0) cpi->svc.high_source_sad_superframe = 0;
 
+  if (cpi->svc.temporal_layering_mode != VP9E_TEMPORAL_LAYERING_MODE_BYPASS &&
+      cpi->svc.last_layer_dropped[cpi->svc.spatial_layer_id]) {
+    // For fixed/non-flexible mode, if the previous frame (same spatial layer
+    // from previous superframe) was dropped, make sure the lst_fb_idx
+    // for this frame corresponds to the buffer index updated on (last) encoded
+    // TL0 frame (with same spatial layer).
+    cpi->lst_fb_idx = cpi->svc.fb_idx_upd_tl0[cpi->svc.spatial_layer_id];
+  }
+
   if (vp9_set_size_literal(cpi, width, height) != 0)
     return VPX_CODEC_INVALID_PARAM;
 
diff --git a/vp9/encoder/vp9_svc_layercontext.h b/vp9/encoder/vp9_svc_layercontext.h
index fb3127687..617717049 100644
--- a/vp9/encoder/vp9_svc_layercontext.h
+++ b/vp9/encoder/vp9_svc_layercontext.h
@@ -138,6 +138,10 @@ typedef struct SVC {
   uint8_t reference_last[VPX_SS_MAX_LAYERS];
   uint8_t reference_golden[VPX_SS_MAX_LAYERS];
   uint8_t reference_altref[VPX_SS_MAX_LAYERS];
+
+  // Keep track of the frame buffer index updated/refreshed on the base
+  // temporal superframe.
+  uint8_t fb_idx_upd_tl0[VPX_SS_MAX_LAYERS];
 } SVC;
 
 struct VP9_COMP;