From 277338f7488d40d27a9ea8d3a5b2bf1a0f32aa95 Mon Sep 17 00:00:00 2001
From: Minghai Shang <minghai@google.com>
Date: Tue, 24 Jun 2014 14:01:17 -0700
Subject: [spatial svc]Implement lag in frames for spatial svc

Change-Id: I930dced169c9d53f8044d2754a04332138347409
---
 vp9/encoder/vp9_svc_layercontext.c | 99 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 99 insertions(+)

(limited to 'vp9/encoder/vp9_svc_layercontext.c')

diff --git a/vp9/encoder/vp9_svc_layercontext.c b/vp9/encoder/vp9_svc_layercontext.c
index 84f344945..07c17b22a 100644
--- a/vp9/encoder/vp9_svc_layercontext.c
+++ b/vp9/encoder/vp9_svc_layercontext.c
@@ -12,6 +12,7 @@
 
 #include "vp9/encoder/vp9_encoder.h"
 #include "vp9/encoder/vp9_svc_layercontext.h"
+#include "vp9/encoder/vp9_extend.h"
 
 void vp9_init_layer_context(VP9_COMP *const cpi) {
   SVC *const svc = &cpi->svc;
@@ -209,3 +210,101 @@ int vp9_is_upper_layer_key_frame(const VP9_COMP *const cpi) {
          cpi->svc.spatial_layer_id > 0 &&
          cpi->svc.layer_context[cpi->svc.spatial_layer_id].is_key_frame;
 }
+
+int vp9_svc_lookahead_push(const VP9_COMP *const cpi, struct lookahead_ctx *ctx,
+                           YV12_BUFFER_CONFIG *src, int64_t ts_start,
+                           int64_t ts_end, unsigned int flags) {
+  struct lookahead_entry *buf;
+  int i, index;
+
+  if (vp9_lookahead_push(ctx, src, ts_start, ts_end, flags))
+    return 1;
+
+  index = ctx->write_idx - 1;
+  if (index < 0)
+    index += ctx->max_sz;
+
+  buf = ctx->buf + index;
+
+  if (buf == NULL)
+    return 1;
+
+  // Store svc parameters for each layer
+  for (i = 0; i < cpi->svc.number_spatial_layers; ++i)
+    buf->svc_params[i] = cpi->svc.layer_context[i].svc_params_received;
+
+  return 0;
+}
+
+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;
+
+  // Find the next layer to be encoded
+  for (layer_id = 0; layer_id < cpi->svc.number_spatial_layers; ++layer_id) {
+    if (buf->svc_params[layer_id].spatial_layer >=0)
+      break;
+  }
+
+  if (layer_id == cpi->svc.number_spatial_layers)
+    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;
+
+  if (vp9_set_size_literal(cpi, layer_param->width, layer_param->height) != 0)
+    return VPX_CODEC_INVALID_PARAM;
+
+  cpi->oxcf.worst_allowed_q =
+      vp9_quantizer_to_qindex(layer_param->max_quantizer);
+  cpi->oxcf.best_allowed_q =
+      vp9_quantizer_to_qindex(layer_param->min_quantizer);
+
+  vp9_change_config(cpi, &cpi->oxcf);
+
+  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);
+
+  return 0;
+}
+
+struct lookahead_entry *vp9_svc_lookahead_peek(VP9_COMP *const cpi,
+                                               struct lookahead_ctx *ctx,
+                                               int index, int copy_params) {
+  struct lookahead_entry *buf = vp9_lookahead_peek(ctx, index);
+
+  if (buf != NULL && copy_params != 0) {
+    if (copy_svc_params(cpi, buf) != 0)
+      return NULL;
+  }
+  return buf;
+}
+
+struct lookahead_entry *vp9_svc_lookahead_pop(VP9_COMP *const cpi,
+                                              struct lookahead_ctx *ctx,
+                                              int drain) {
+  struct lookahead_entry *buf = NULL;
+
+  if (ctx->sz && (drain || ctx->sz == ctx->max_sz - MAX_PRE_FRAMES)) {
+    buf = vp9_svc_lookahead_peek(cpi, ctx, 0, 1);
+    if (buf != NULL) {
+      // Only remove the buffer when pop the highest layer. Simply set the
+      // spatial_layer to -1 for lower layers.
+      buf->svc_params[cpi->svc.spatial_layer_id].spatial_layer = -1;
+      if (cpi->svc.spatial_layer_id == cpi->svc.number_spatial_layers - 1) {
+        vp9_lookahead_pop(ctx, drain);
+      }
+    }
+  }
+
+  return buf;
+}
-- 
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