Derive current layer from TL frame config.

webrtc/modules/video_coding/codecs/vp8/default_temporal_layers.cc

Index: webrtc/modules/video_coding/codecs/vp8/default_temporal_layers.cc
diff --git a/webrtc/modules/video_coding/codecs/vp8/default_temporal_layers.cc b/webrtc/modules/video_coding/codecs/vp8/default_temporal_layers.cc
index 30374a3b33cabb629974aabbd1c2a5dea7c576e4..408daa05c9442624cff8f1ddfb696a84ca9f5470 100644
--- a/webrtc/modules/video_coding/codecs/vp8/default_temporal_layers.cc
+++ b/webrtc/modules/video_coding/codecs/vp8/default_temporal_layers.cc
@@ -25,27 +25,31 @@
 
 namespace webrtc {
 
-TemporalReferences::TemporalReferences(TemporalBufferFlags last,
-                                       TemporalBufferFlags golden,
-                                       TemporalBufferFlags arf)
-    : TemporalReferences(last, golden, arf, false, false) {}
-
-TemporalReferences::TemporalReferences(TemporalBufferFlags last,
-                                       TemporalBufferFlags golden,
-                                       TemporalBufferFlags arf,
-                                       int extra_flags)
-    : TemporalReferences(last,
-                         golden,
-                         arf,
-                         (extra_flags & kLayerSync) != 0,
-                         (extra_flags & kFreezeEntropy) != 0) {}
-
-TemporalReferences::TemporalReferences(TemporalBufferFlags last,
-                                       TemporalBufferFlags golden,
-                                       TemporalBufferFlags arf,
-                                       bool layer_sync,
-                                       bool freeze_entropy)
-    : drop_frame(last == kNone && golden == kNone && arf == kNone),
+TemporalLayers::FrameConfig::FrameConfig() {}
+
+TemporalLayers::FrameConfig::FrameConfig(TemporalLayers::BufferFlags last,
+                                         TemporalLayers::BufferFlags golden,
+                                         TemporalLayers::BufferFlags arf)
+    : FrameConfig(last, golden, arf, false, false) {}
+
+TemporalLayers::FrameConfig::FrameConfig(TemporalLayers::BufferFlags last,
+                                         TemporalLayers::BufferFlags golden,
+                                         TemporalLayers::BufferFlags arf,
+                                         int extra_flags)
+    : FrameConfig(last,
+                  golden,
+                  arf,
+                  (extra_flags & kLayerSync) != 0,
+                  (extra_flags & kFreezeEntropy) != 0) {}
+
+TemporalLayers::FrameConfig::FrameConfig(TemporalLayers::BufferFlags last,
+                                         TemporalLayers::BufferFlags golden,
+                                         TemporalLayers::BufferFlags arf,
+                                         bool layer_sync,
+                                         bool freeze_entropy)
+    : drop_frame(last == TemporalLayers::kNone &&
+                 golden == TemporalLayers::kNone &&
+                 arf == TemporalLayers::kNone),
       last_buffer_flags(last),
       golden_buffer_flags(golden),
       arf_buffer_flags(arf),
@@ -86,8 +90,7 @@ std::vector<unsigned int> GetTemporalIds(size_t num_layers) {
   return {0};
 }
 
-std::vector<TemporalReferences> GetTemporalPattern(
-    size_t num_layers) {
+std::vector<TemporalLayers::FrameConfig> GetTemporalPattern(size_t num_layers) {
   // For indexing in the patterns described below (which temporal layers they
   // belong to), see the diagram above.
   // Layer sync is done similarly for all patterns (except single stream) and
@@ -104,74 +107,128 @@ std::vector<TemporalReferences> GetTemporalPattern(
   switch (num_layers) {
     case 1:
       // All frames reference all buffers and the 'last' buffer is updated.
-      return {TemporalReferences(kReferenceAndUpdate, kReference, kReference)};
+      return {TemporalLayers::FrameConfig(TemporalLayers::kReferenceAndUpdate,
+                                          TemporalLayers::kReference,
+                                          TemporalLayers::kReference)};
     case 2:
       // All layers can reference but not update the 'alt' buffer, this means
       // that the 'alt' buffer reference is effectively the last keyframe.
       // TL0 also references and updates the 'last' buffer.
       // TL1 also references 'last' and references and updates 'golden'.
-      return {TemporalReferences(kReferenceAndUpdate, kUpdate, kReference),
-              TemporalReferences(kReference, kUpdate, kReference, kLayerSync),
-              TemporalReferences(kReferenceAndUpdate, kNone, kReference),
-              TemporalReferences(kReference, kReferenceAndUpdate, kReference),
-              TemporalReferences(kReferenceAndUpdate, kNone, kReference),
-              TemporalReferences(kReference, kReferenceAndUpdate, kReference),
-              TemporalReferences(kReferenceAndUpdate, kNone, kReference),
-              TemporalReferences(kReference, kReference, kReference,
-                                 kFreezeEntropy)};
+      return {TemporalLayers::FrameConfig(TemporalLayers::kReferenceAndUpdate,
+                                          TemporalLayers::kUpdate,
+                                          TemporalLayers::kReference),
+              TemporalLayers::FrameConfig(
+                  TemporalLayers::kReference, TemporalLayers::kUpdate,
+                  TemporalLayers::kReference, kLayerSync),
+              TemporalLayers::FrameConfig(TemporalLayers::kReferenceAndUpdate,
+                                          TemporalLayers::kNone,
+                                          TemporalLayers::kReference),
+              TemporalLayers::FrameConfig(TemporalLayers::kReference,
+                                          TemporalLayers::kReferenceAndUpdate,
+                                          TemporalLayers::kReference),
+              TemporalLayers::FrameConfig(TemporalLayers::kReferenceAndUpdate,
+                                          TemporalLayers::kNone,
+                                          TemporalLayers::kReference),
+              TemporalLayers::FrameConfig(TemporalLayers::kReference,
+                                          TemporalLayers::kReferenceAndUpdate,
+                                          TemporalLayers::kReference),
+              TemporalLayers::FrameConfig(TemporalLayers::kReferenceAndUpdate,
+                                          TemporalLayers::kNone,
+                                          TemporalLayers::kReference),
+              TemporalLayers::FrameConfig(
+                  TemporalLayers::kReference, TemporalLayers::kReference,
+                  TemporalLayers::kReference, kFreezeEntropy)};
     case 3:
       // All layers can reference but not update the 'alt' buffer, this means
       // that the 'alt' buffer reference is effectively the last keyframe.
       // TL0 also references and updates the 'last' buffer.
       // TL1 also references 'last' and references and updates 'golden'.
       // TL2 references both 'last' and 'golden' but updates no buffer.
-      return {TemporalReferences(kReferenceAndUpdate, kUpdate, kReference),
-              TemporalReferences(kReference, kNone, kReference,
-                                 kLayerSync | kFreezeEntropy),
-              TemporalReferences(kReference, kUpdate, kReference, kLayerSync),
-              TemporalReferences(kReference, kReference, kReference,
-                                 kFreezeEntropy),
-              TemporalReferences(kReferenceAndUpdate, kNone, kReference),
-              TemporalReferences(kReference, kReference, kReference,
-                                 kFreezeEntropy),
-              TemporalReferences(kReference, kReferenceAndUpdate, kReference),
-              TemporalReferences(kReference, kReference, kReference,
-                                 kFreezeEntropy)};
+      return {TemporalLayers::FrameConfig(TemporalLayers::kReferenceAndUpdate,
+                                          TemporalLayers::kUpdate,
+                                          TemporalLayers::kReference),
+              TemporalLayers::FrameConfig(
+                  TemporalLayers::kReference, TemporalLayers::kNone,
+                  TemporalLayers::kReference, kLayerSync | kFreezeEntropy),
+              TemporalLayers::FrameConfig(
+                  TemporalLayers::kReference, TemporalLayers::kUpdate,
+                  TemporalLayers::kReference, kLayerSync),
+              TemporalLayers::FrameConfig(
+                  TemporalLayers::kReference, TemporalLayers::kReference,
+                  TemporalLayers::kReference, kFreezeEntropy),
+              TemporalLayers::FrameConfig(TemporalLayers::kReferenceAndUpdate,
+                                          TemporalLayers::kNone,
+                                          TemporalLayers::kReference),
+              TemporalLayers::FrameConfig(
+                  TemporalLayers::kReference, TemporalLayers::kReference,
+                  TemporalLayers::kReference, kFreezeEntropy),
+              TemporalLayers::FrameConfig(TemporalLayers::kReference,
+                                          TemporalLayers::kReferenceAndUpdate,
+                                          TemporalLayers::kReference),
+              TemporalLayers::FrameConfig(
+                  TemporalLayers::kReference, TemporalLayers::kReference,
+                  TemporalLayers::kReference, kFreezeEntropy)};
     case 4:
       // TL0 references and updates only the 'last' buffer.
       // TL1 references 'last' and updates and references 'golden'.
       // TL2 references 'last' and 'golden', and references and updates 'arf'.
       // TL3 references all buffers but update none of them.
-      return {TemporalReferences(kReferenceAndUpdate, kNone, kNone),
-              TemporalReferences(kReference, kReference, kReference,
-                                 kLayerSync | kFreezeEntropy),
-              TemporalReferences(kReference, kNone, kUpdate, kLayerSync),
-              TemporalReferences(kReference, kReference, kReference,
-                                 kLayerSync | kFreezeEntropy),
-              TemporalReferences(kReference, kUpdate, kNone, kLayerSync),
-              TemporalReferences(kReference, kReference, kReference,
-                                 kLayerSync | kFreezeEntropy),
-              TemporalReferences(kReference, kReference, kReferenceAndUpdate),
-              TemporalReferences(kReference, kReference, kReference,
-                                 kLayerSync | kFreezeEntropy),
-              TemporalReferences(kReferenceAndUpdate, kNone, kNone),
-              TemporalReferences(kReference, kReference, kReference,
-                                 kLayerSync | kFreezeEntropy),
-              TemporalReferences(kReference, kReference, kReferenceAndUpdate),
-              TemporalReferences(kReference, kReference, kReference,
-                                 kLayerSync | kFreezeEntropy),
-              TemporalReferences(kReference, kReferenceAndUpdate, kNone),
-              TemporalReferences(kReference, kReference, kReference,
-                                 kLayerSync | kFreezeEntropy),
-              TemporalReferences(kReference, kReference, kReferenceAndUpdate),
-              TemporalReferences(kReference, kReference, kReference,
-                                 kLayerSync | kFreezeEntropy)};
+      return {TemporalLayers::FrameConfig(TemporalLayers::kReferenceAndUpdate,
+                                          TemporalLayers::kNone,
+                                          TemporalLayers::kNone),
+              TemporalLayers::FrameConfig(
+                  TemporalLayers::kReference, TemporalLayers::kReference,
+                  TemporalLayers::kReference, kLayerSync | kFreezeEntropy),
+              TemporalLayers::FrameConfig(TemporalLayers::kReference,
+                                          TemporalLayers::kNone,
+                                          TemporalLayers::kUpdate, kLayerSync),
+              TemporalLayers::FrameConfig(
+                  TemporalLayers::kReference, TemporalLayers::kReference,
+                  TemporalLayers::kReference, kLayerSync | kFreezeEntropy),
+              TemporalLayers::FrameConfig(TemporalLayers::kReference,
+                                          TemporalLayers::kUpdate,
+                                          TemporalLayers::kNone, kLayerSync),
+              TemporalLayers::FrameConfig(
+                  TemporalLayers::kReference, TemporalLayers::kReference,
+                  TemporalLayers::kReference, kLayerSync | kFreezeEntropy),
+              TemporalLayers::FrameConfig(TemporalLayers::kReference,
+                                          TemporalLayers::kReference,
+                                          TemporalLayers::kReferenceAndUpdate),
+              TemporalLayers::FrameConfig(
+                  TemporalLayers::kReference, TemporalLayers::kReference,
+                  TemporalLayers::kReference, kLayerSync | kFreezeEntropy),
+              TemporalLayers::FrameConfig(TemporalLayers::kReferenceAndUpdate,
+                                          TemporalLayers::kNone,
+                                          TemporalLayers::kNone),
+              TemporalLayers::FrameConfig(
+                  TemporalLayers::kReference, TemporalLayers::kReference,
+                  TemporalLayers::kReference, kLayerSync | kFreezeEntropy),
+              TemporalLayers::FrameConfig(TemporalLayers::kReference,
+                                          TemporalLayers::kReference,
+                                          TemporalLayers::kReferenceAndUpdate),
+              TemporalLayers::FrameConfig(
+                  TemporalLayers::kReference, TemporalLayers::kReference,
+                  TemporalLayers::kReference, kLayerSync | kFreezeEntropy),
+              TemporalLayers::FrameConfig(TemporalLayers::kReference,
+                                          TemporalLayers::kReferenceAndUpdate,
+                                          TemporalLayers::kNone),
+              TemporalLayers::FrameConfig(
+                  TemporalLayers::kReference, TemporalLayers::kReference,
+                  TemporalLayers::kReference, kLayerSync | kFreezeEntropy),
+              TemporalLayers::FrameConfig(TemporalLayers::kReference,
+                                          TemporalLayers::kReference,
+                                          TemporalLayers::kReferenceAndUpdate),
+              TemporalLayers::FrameConfig(
+                  TemporalLayers::kReference, TemporalLayers::kReference,
+                  TemporalLayers::kReference, kLayerSync | kFreezeEntropy)};
     default:
       RTC_NOTREACHED();
       break;
   }
   RTC_NOTREACHED();
-  return {TemporalReferences(kNone, kNone, kNone)};
+  return {TemporalLayers::FrameConfig(
+      TemporalLayers::kNone, TemporalLayers::kNone, TemporalLayers::kNone)};
 }
 
 }  // namespace
@@ -190,8 +247,10 @@ DefaultTemporalLayers::DefaultTemporalLayers(int number_of_temporal_layers,
   RTC_CHECK_LE(number_of_temporal_layers, 4);
 }
 
-int DefaultTemporalLayers::CurrentLayerId() const {
-  return temporal_ids_[pattern_idx_ % temporal_ids_.size()];
+int DefaultTemporalLayers::GetTemporalLayerId(
+    TemporalLayers::FrameConfig tl_config) const {
+  RTC_DCHECK(!tl_config.drop_frame);
+  return temporal_ids_[tl_config.pattern_idx % temporal_ids_.size()];
 }
 
 std::vector<uint32_t> DefaultTemporalLayers::OnRatesUpdated(
@@ -245,15 +304,20 @@ bool DefaultTemporalLayers::UpdateConfiguration(vpx_codec_enc_cfg_t* cfg) {
 }
 
 // TODO(pbos): Name method so that it's obvious that it updates state.

[sprang_webrtc, 2017/05/03 15:18:43]

Remove todo?

[pbos-webrtc, 2017/05/04 10:52:22]

Done.

-TemporalReferences DefaultTemporalLayers::UpdateLayerConfig(
+TemporalLayers::FrameConfig DefaultTemporalLayers::UpdateLayerConfig(
     uint32_t timestamp) {
   RTC_DCHECK_GT(num_layers_, 0);
   RTC_DCHECK_LT(0, temporal_pattern_.size());
-  return temporal_pattern_[++pattern_idx_ % temporal_pattern_.size()];
+  int pattern_idx = ++pattern_idx_;

[sprang_webrtc, 2017/05/03 15:18:43]

Is it intentional that we let pattern_idx_ go up to 255 before overflowing and
wrapping around rather than explicitly wrapping it at temporal_pattern_.size() ?
Right now this looks to me like it works only because temporal_pattern_.size()
always happen to be a divisor of 256..?
If it is desired I think a DCHECK and/or comment somewhere would be in order :)

[pbos-webrtc, 2017/05/04 10:52:22]

Did as suggested (explicitly wrap). I added a DCHECK above since pattern_idx is
also used to index into temporal_ids_, and a comment saying that if
temporal_ids_ is ever larger than temporal_patterns_ it needs to wrap at the
largest one.

+  TemporalLayers::FrameConfig tl_config =
+      temporal_pattern_[pattern_idx_ % temporal_pattern_.size()];
+  tl_config.pattern_idx = pattern_idx;
+  return tl_config;
 }
 
 void DefaultTemporalLayers::PopulateCodecSpecific(
     bool frame_is_keyframe,
+    TemporalLayers::FrameConfig tl_config,
     CodecSpecificInfoVP8* vp8_info,
     uint32_t timestamp) {
   RTC_DCHECK_GT(num_layers_, 0);
@@ -267,11 +331,9 @@ void DefaultTemporalLayers::PopulateCodecSpecific(
       vp8_info->temporalIdx = 0;
       vp8_info->layerSync = true;
     } else {
-      vp8_info->temporalIdx = CurrentLayerId();
-      TemporalReferences temporal_reference =
-          temporal_pattern_[pattern_idx_ % temporal_pattern_.size()];
+      vp8_info->temporalIdx = GetTemporalLayerId(tl_config);
 
-      vp8_info->layerSync = temporal_reference.layer_sync;
+      vp8_info->layerSync = tl_config.layer_sync;
     }
     if (last_base_layer_sync_ && vp8_info->temporalIdx != 0) {
       // Regardless of pattern the frame after a base layer sync will always