libvpx: Pull from upstream

source/libvpx/vp9/encoder/vp9_encoder.h

Index: source/libvpx/vp9/encoder/vp9_encoder.h
===================================================================
--- source/libvpx/vp9/encoder/vp9_encoder.h	(revision 284462)
+++ source/libvpx/vp9/encoder/vp9_encoder.h	(working copy)
@@ -195,6 +195,7 @@
   int ts_number_layers;  // Number of temporal layers.
   // Bitrate allocation for spatial layers.
   int ss_target_bitrate[VPX_SS_MAX_LAYERS];
+  int ss_play_alternate[VPX_SS_MAX_LAYERS];
   // Bitrate allocation (CBR mode) and framerate factor, for temporal layers.
   int ts_target_bitrate[VPX_TS_MAX_LAYERS];
   int ts_rate_decimator[VPX_TS_MAX_LAYERS];
@@ -226,13 +227,13 @@
   struct vpx_fixed_buf         two_pass_stats_in;
   struct vpx_codec_pkt_list  *output_pkt_list;
 
+#if CONFIG_FP_MB_STATS
+  struct vpx_fixed_buf         firstpass_mb_stats_in;
+#endif
+
   vp8e_tuning tuning;
 } VP9EncoderConfig;
 
-static INLINE int is_altref_enabled(const VP9EncoderConfig *cfg) {
-  return cfg->mode != REALTIME && cfg->play_alternate && cfg->lag_in_frames > 0;
-}
-
 static INLINE int is_lossless_requested(const VP9EncoderConfig *cfg) {
   return cfg->best_allowed_q == 0 && cfg->worst_allowed_q == 0;
 }
@@ -535,6 +536,13 @@
 
 void vp9_apply_encoding_flags(VP9_COMP *cpi, vpx_enc_frame_flags_t flags);
 
+static INLINE int is_altref_enabled(const VP9_COMP *const cpi) {
+  return cpi->oxcf.mode != REALTIME && cpi->oxcf.lag_in_frames > 0 &&
+         (cpi->oxcf.play_alternate &&
+          (!(cpi->use_svc && cpi->svc.number_temporal_layers == 1) ||
+           cpi->oxcf.ss_play_alternate[cpi->svc.spatial_layer_id]));
+}
+
 static INLINE void set_ref_ptrs(VP9_COMMON *cm, MACROBLOCKD *xd,
                                 MV_REFERENCE_FRAME ref0,
                                 MV_REFERENCE_FRAME ref1) {