libvpx: Pull from upstream

source/libvpx/vp9/encoder/vp9_svc_layercontext.c

Index: source/libvpx/vp9/encoder/vp9_svc_layercontext.c
===================================================================
--- source/libvpx/vp9/encoder/vp9_svc_layercontext.c	(revision 284462)
+++ source/libvpx/vp9/encoder/vp9_svc_layercontext.c	(working copy)
@@ -19,6 +19,7 @@
   const VP9EncoderConfig *const oxcf = &cpi->oxcf;
   int layer;
   int layer_end;
+  int alt_ref_idx = svc->number_spatial_layers;
 
   svc->spatial_layer_id = 0;
   svc->temporal_layer_id = 0;
@@ -34,7 +35,6 @@
     RATE_CONTROL *const lrc = &lc->rc;
     int i;
     lc->current_video_frame_in_layer = 0;
-    lrc->avg_frame_qindex[INTER_FRAME] = oxcf->worst_allowed_q;
     lrc->ni_av_qi = oxcf->worst_allowed_q;
     lrc->total_actual_bits = 0;
     lrc->total_target_vs_actual = 0;
@@ -48,14 +48,24 @@
     for (i = 0; i < RATE_FACTOR_LEVELS; ++i) {
       lrc->rate_correction_factors[i] = 1.0;
     }
+    lc->layer_size = 0;
 
     if (svc->number_temporal_layers > 1) {
       lc->target_bandwidth = oxcf->ts_target_bitrate[layer];
       lrc->last_q[INTER_FRAME] = oxcf->worst_allowed_q;
+      lrc->avg_frame_qindex[INTER_FRAME] = oxcf->worst_allowed_q;
     } else {
       lc->target_bandwidth = oxcf->ss_target_bitrate[layer];
       lrc->last_q[KEY_FRAME] = oxcf->best_allowed_q;
       lrc->last_q[INTER_FRAME] = oxcf->best_allowed_q;
+      lrc->avg_frame_qindex[KEY_FRAME] = (oxcf->worst_allowed_q +
+                                          oxcf->best_allowed_q) / 2;
+      lrc->avg_frame_qindex[INTER_FRAME] = (oxcf->worst_allowed_q +
+                                            oxcf->best_allowed_q) / 2;
+      if (oxcf->ss_play_alternate[layer])
+        lc->alt_ref_idx = alt_ref_idx++;
+      else
+        lc->alt_ref_idx = -1;
     }
 
     lrc->buffer_level = vp9_rescale((int)(oxcf->starting_buffer_level_ms),
@@ -153,7 +163,7 @@
                                    oxcf->two_pass_vbrmin_section / 100);
   lrc->max_frame_bandwidth = (int)(((int64_t)lrc->avg_frame_bandwidth *
                                    oxcf->two_pass_vbrmax_section) / 100);
-  vp9_rc_set_gf_max_interval(oxcf, lrc);
+  vp9_rc_set_gf_max_interval(cpi, lrc);
 }
 
 void vp9_restore_layer_context(VP9_COMP *const cpi) {
@@ -164,6 +174,7 @@
   cpi->rc = lc->rc;
   cpi->twopass = lc->twopass;
   cpi->oxcf.target_bandwidth = lc->target_bandwidth;
+  cpi->alt_ref_source = lc->alt_ref_source;
   // Reset the frames_since_key and frames_to_key counters to their values
   // before the layer restore. Keep these defined for the stream (not layer).
   if (cpi->svc.number_temporal_layers > 1) {
@@ -179,6 +190,7 @@
   lc->rc = cpi->rc;
   lc->twopass = cpi->twopass;
   lc->target_bandwidth = (int)oxcf->target_bandwidth;
+  lc->alt_ref_source = cpi->alt_ref_source;
 }
 
 void vp9_init_second_pass_spatial_svc(VP9_COMP *cpi) {
@@ -239,7 +251,7 @@
 static int copy_svc_params(VP9_COMP *const cpi, struct lookahead_entry *buf) {
   int layer_id;
   vpx_svc_parameters_t *layer_param;
-  vpx_enc_frame_flags_t flags;
+  LAYER_CONTEXT *lc;
 
   // Find the next layer to be encoded
   for (layer_id = 0; layer_id < cpi->svc.number_spatial_layers; ++layer_id) {
@@ -251,13 +263,47 @@
     return 1;
 
   layer_param = &buf->svc_params[layer_id];
-  buf->flags = flags = layer_param->flags;
   cpi->svc.spatial_layer_id = layer_param->spatial_layer;
   cpi->svc.temporal_layer_id = layer_param->temporal_layer;
-  cpi->lst_fb_idx = layer_param->lst_fb_idx;
-  cpi->gld_fb_idx = layer_param->gld_fb_idx;
-  cpi->alt_fb_idx = layer_param->alt_fb_idx;
 
+  cpi->lst_fb_idx = cpi->svc.spatial_layer_id;
+
+  if (cpi->svc.spatial_layer_id < 1)
+    cpi->gld_fb_idx = cpi->lst_fb_idx;
+  else
+    cpi->gld_fb_idx = cpi->svc.spatial_layer_id - 1;
+
+  lc = &cpi->svc.layer_context[cpi->svc.spatial_layer_id];
+
+  if (lc->current_video_frame_in_layer == 0) {
+    if (cpi->svc.spatial_layer_id >= 2)
+      cpi->alt_fb_idx = cpi->svc.spatial_layer_id - 2;
+    else
+      cpi->alt_fb_idx = cpi->lst_fb_idx;
+  } else {
+    if (cpi->oxcf.ss_play_alternate[cpi->svc.spatial_layer_id]) {
+      cpi->alt_fb_idx = lc->alt_ref_idx;
+      if (!lc->has_alt_frame)
+        cpi->ref_frame_flags &= (~VP9_ALT_FLAG);
+    } else {
+      // Find a proper alt_fb_idx for layers that don't have alt ref frame
+      if (cpi->svc.spatial_layer_id == 0) {
+        cpi->alt_fb_idx = cpi->lst_fb_idx;
+      } else {
+        LAYER_CONTEXT *lc_lower =
+            &cpi->svc.layer_context[cpi->svc.spatial_layer_id - 1];
+
+        if (cpi->oxcf.ss_play_alternate[cpi->svc.spatial_layer_id - 1] &&
+            lc_lower->alt_ref_source != NULL)
+          cpi->alt_fb_idx = lc_lower->alt_ref_idx;
+        else if (cpi->svc.spatial_layer_id >= 2)
+          cpi->alt_fb_idx = cpi->svc.spatial_layer_id - 2;
+        else
+          cpi->alt_fb_idx = cpi->lst_fb_idx;
+      }
+    }
+  }
+
   if (vp9_set_size_literal(cpi, layer_param->width, layer_param->height) != 0)
     return VPX_CODEC_INVALID_PARAM;
 
@@ -270,9 +316,7 @@
 
   vp9_set_high_precision_mv(cpi, 1);
 
-  // Retrieve the encoding flags for each layer and apply it to encoder.
-  // It includes reference frame flags and update frame flags.
-  vp9_apply_encoding_flags(cpi, flags);
+  cpi->alt_ref_source = get_layer_context(&cpi->svc)->alt_ref_source;
 
   return 0;
 }