shithub: libvpx

Download patch

ref: 20ed66478a588b9f5ad4468b09b40564cbd7f3b4
parent: 00207bc81247af208397ca31cb74f02fa7254dbc
author: Jingning Han <jingning@google.com>
date: Tue Aug 28 10:08:02 EDT 2018 

Enable adaptive rate allocation for multi-layer ARFs

Increase the bit allocation for the intermediate layer ARFs. The
current strategy assigns higher offset to the lower layer ARFs.
The needed budget is borrowed from the base layer ARF allocation.

Change-Id: I16b6e9cce4dab8e73e7b097674d1a8504205026e


--- a/vp9/encoder/vp9_firstpass.c
+++ b/vp9/encoder/vp9_firstpass.c
@@ -2333,8 +2333,8 @@
   gf_group->brf_src_offset[frame_index] = 0;
 }
 
-static void find_arf_order(GF_GROUP *gf_group, int *layer_depth,
-                           int *index_counter, int depth, int start, int end) {
+static void find_arf_order(GF_GROUP *gf_group, int *index_counter, int depth,
+                           int start, int end) {
   const int mid = (start + end) >> 1;
   const int min_frame_interval = 3;
 
@@ -2345,6 +2345,7 @@
       gf_group->update_type[*index_counter] = LF_UPDATE;
       gf_group->arf_src_offset[*index_counter] = 0;
       gf_group->rf_level[*index_counter] = INTER_NORMAL;
+      gf_group->layer_depth[*index_counter] = depth;
       ++(*index_counter);
     }
     return;
@@ -2353,20 +2354,21 @@
   assert(abs(mid - start) >= 1 && abs(mid - end) >= 1);
 
   // Process ARF frame
-  layer_depth[*index_counter] = depth;
+  gf_group->layer_depth[*index_counter] = depth;
   gf_group->update_type[*index_counter] = ARF_UPDATE;
   gf_group->arf_src_offset[*index_counter] = mid - start;
   gf_group->rf_level[*index_counter] = GF_ARF_LOW;
   ++(*index_counter);
 
-  find_arf_order(gf_group, layer_depth, index_counter, depth + 1, start, mid);
+  find_arf_order(gf_group, index_counter, depth + 1, start, mid);
 
   gf_group->update_type[*index_counter] = USE_BUF_FRAME;
   gf_group->arf_src_offset[*index_counter] = 0;
   gf_group->rf_level[*index_counter] = INTER_NORMAL;
+  gf_group->layer_depth[*index_counter] = depth;
   ++(*index_counter);
 
-  find_arf_order(gf_group, layer_depth, index_counter, depth + 1, mid + 1, end);
+  find_arf_order(gf_group, index_counter, depth + 1, mid + 1, end);
 }
 
 static int define_gf_group_structure(VP9_COMP *cpi) {
@@ -2379,7 +2381,6 @@
   int mid_frame_idx;
   unsigned char arf_buffer_indices[MAX_ACTIVE_ARFS];
   int normal_frames;
-  int layer_depth[MAX_LAG_BUFFERS];
 
   key_frame = cpi->common.frame_type == KEY_FRAME;
 
@@ -2429,10 +2430,9 @@
   }
 
   if (rc->source_alt_ref_pending && cpi->multi_layer_arf) {
-    layer_depth[frame_index] = 1;
+    gf_group->layer_depth[frame_index] = 1;
 
-    find_arf_order(gf_group, layer_depth, &frame_index, 2, 0,
-                   rc->baseline_gf_interval - 1);
+    find_arf_order(gf_group, &frame_index, 2, 0, rc->baseline_gf_interval - 1);
 
     if (rc->source_alt_ref_pending) {
       gf_group->update_type[frame_index] = OVERLAY_UPDATE;
@@ -2442,8 +2442,6 @@
       gf_group->rf_level[frame_index] = GF_ARF_STD;
     }
 
-    (void)layer_depth;
-
     return frame_index;
   }
 
@@ -2706,17 +2704,49 @@
 
   if (cpi->multi_layer_arf) {
     int idx;
+    int total_delta = 0;
+    int gap_bits;
     target_frame_size = normal_frame_bits;
     target_frame_size =
         clamp(target_frame_size, 0, VPXMIN(max_bits, (int)total_group_bits));
 
+    gap_bits = VPXMAX(0, gf_arf_bits - target_frame_size);
+
     for (idx = frame_index; idx < gop_frames; ++idx) {
-      if (gf_group->update_type[idx] == USE_BUF_FRAME)
-        gf_group->bit_allocation[idx] = 0;
-      else
-        gf_group->bit_allocation[idx] = target_frame_size;
+      int layer_arf_delta;
+      if (gf_group->update_type[idx] == ARF_UPDATE) {
+        layer_arf_delta = gap_bits >> (gf_group->layer_depth[idx] + 2);
+        total_delta += layer_arf_delta;
+      }
     }
+
+    total_group_bits -= total_delta;
+
+    if (normal_frames > 1)
+      normal_frame_bits = (int)(total_group_bits / normal_frames);
+    else
+      normal_frame_bits = (int)total_group_bits;
+
+    target_frame_size = normal_frame_bits;
+    target_frame_size =
+        clamp(target_frame_size, 0, VPXMIN(max_bits, (int)total_group_bits));
+
+    // The first layer ARF has its bit allocation assigned.
+    for (idx = frame_index; idx < gop_frames; ++idx) {
+      int layer_arf_delta;
+      switch (gf_group->update_type[idx]) {
+        case ARF_UPDATE:
+          layer_arf_delta = gap_bits >> (gf_group->layer_depth[idx] + 1);
+          gf_group->bit_allocation[idx] = target_frame_size + layer_arf_delta;
+          break;
+        case USE_BUF_FRAME: gf_group->bit_allocation[idx] = 0; break;
+        default: gf_group->bit_allocation[idx] = target_frame_size; break;
+      }
+    }
     gf_group->bit_allocation[idx] = 0;
+
+    // Adjust the first layer ARF rate allocation.
+    gf_group->bit_allocation[1] = gf_arf_bits;
 
     for (idx = 0; idx < gop_frames; ++idx)
       if (gf_group->update_type[idx] == LF_UPDATE) break;
--- a/vp9/encoder/vp9_firstpass.h
+++ b/vp9/encoder/vp9_firstpass.h
@@ -138,6 +138,7 @@
   RATE_FACTOR_LEVEL rf_level[MAX_STATIC_GF_GROUP_LENGTH + 2];
   FRAME_UPDATE_TYPE update_type[MAX_STATIC_GF_GROUP_LENGTH + 2];
   unsigned char arf_src_offset[MAX_STATIC_GF_GROUP_LENGTH + 2];
+  unsigned char layer_depth[MAX_STATIC_GF_GROUP_LENGTH + 2];
   unsigned char arf_update_idx[MAX_STATIC_GF_GROUP_LENGTH + 2];
   unsigned char arf_ref_idx[MAX_STATIC_GF_GROUP_LENGTH + 2];
   unsigned char brf_src_offset[MAX_STATIC_GF_GROUP_LENGTH + 2];