Derive current layer from TL frame config.

webrtc/modules/video_coding/codecs/vp8/temporal_layers.h

Index: webrtc/modules/video_coding/codecs/vp8/temporal_layers.h
diff --git a/webrtc/modules/video_coding/codecs/vp8/temporal_layers.h b/webrtc/modules/video_coding/codecs/vp8/temporal_layers.h
index 2a41c6da8b483f6b365acf57f085ced2bc43dc7a..f24398e5ff897193f1f9da13de8f70d2f986d8d1 100644
--- a/webrtc/modules/video_coding/codecs/vp8/temporal_layers.h
+++ b/webrtc/modules/video_coding/codecs/vp8/temporal_layers.h
@@ -24,52 +24,57 @@ namespace webrtc {
 
 struct CodecSpecificInfoVP8;
 
-enum TemporalBufferFlags {
-  kNone = 0,
-  kReference = 1,
-  kUpdate = 2,
-  kReferenceAndUpdate = kReference | kUpdate,
-};
-
+// TODO(pbos): Remove along with layer_sync and freeze_entropy, they are
+// derivable from picture_idx and should be exposed with
+// TL::IsLayerSync(TL::FrameConfig).
 enum TemporalFlags { kLayerSync = 1, kFreezeEntropy = 2 };
 
-struct TemporalReferences {
-  TemporalReferences(TemporalBufferFlags last,
-                     TemporalBufferFlags golden,
-                     TemporalBufferFlags arf);
-  TemporalReferences(TemporalBufferFlags last,
-                     TemporalBufferFlags golden,
-                     TemporalBufferFlags arf,
-                     int extra_flags);
-
-  const bool drop_frame;
-  const TemporalBufferFlags last_buffer_flags;
-  const TemporalBufferFlags golden_buffer_flags;
-  const TemporalBufferFlags arf_buffer_flags;
-
-  // TODO(pbos): Consider breaking these out of here and returning only a
-  // pattern index that needs to be returned to fill CodecSpecificInfoVP8 or
-  // EncodeFlags.
-  const bool layer_sync;
-  const bool freeze_entropy;
-
- private:
-  TemporalReferences(TemporalBufferFlags last,
-                     TemporalBufferFlags golden,
-                     TemporalBufferFlags arf,
-                     bool layer_sync,
-                     bool freeze_entropy);
-};
-
 class TemporalLayers {
  public:
+  enum BufferFlags {
+    kNone = 0,
+    kReference = 1,
+    kUpdate = 2,
+    kReferenceAndUpdate = kReference | kUpdate,
+  };
+
+  struct FrameConfig {
+    FrameConfig();
+
+    FrameConfig(BufferFlags last, BufferFlags golden, BufferFlags arf);
+    FrameConfig(BufferFlags last,
+                BufferFlags golden,
+                BufferFlags arf,
+                int extra_flags);
+
+    bool drop_frame;
+    BufferFlags last_buffer_flags;
+    BufferFlags golden_buffer_flags;
+    BufferFlags arf_buffer_flags;
+
+    // TODO(pbos): Consider breaking these out of here and returning only a
+    // pattern index that needs to be returned to fill CodecSpecificInfoVP8 or
+    // EncodeFlags.
+    bool layer_sync;
+    bool freeze_entropy;
+
+    int pattern_idx;
+
+   private:
+    FrameConfig(BufferFlags last,
+                BufferFlags golden,
+                BufferFlags arf,
+                bool layer_sync,
+                bool freeze_entropy);
+  };
+
   // Factory for TemporalLayer strategy. Default behavior is a fixed pattern
   // of temporal layers. See default_temporal_layers.cc
   virtual ~TemporalLayers() {}
 
   // Returns the recommended VP8 encode flags needed. May refresh the decoder
   // and/or update the reference buffers.
-  virtual TemporalReferences UpdateLayerConfig(uint32_t timestamp) = 0;
+  virtual FrameConfig UpdateLayerConfig(uint32_t timestamp) = 0;
 
   // Update state based on new bitrate target and incoming framerate.
   // Returns the bitrate allocation for the active temporal layers.
@@ -82,12 +87,14 @@ class TemporalLayers {
   virtual bool UpdateConfiguration(vpx_codec_enc_cfg_t* cfg) = 0;
 
   virtual void PopulateCodecSpecific(bool is_keyframe,
+                                     TemporalLayers::FrameConfig tl_config,

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

Since it's a proper struct now, make it const TemporalLayers::FrameConfig&
here, below and in vp8_impl?

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

(FWIW: I didn't because I believe the struct is small enough to be faster to
copy than to pass pointer and dereference, though I agree that style consistency
is more important here.)

 Done.

                                      CodecSpecificInfoVP8* vp8_info,
                                      uint32_t timestamp) = 0;
 
   virtual void FrameEncoded(unsigned int size, int qp) = 0;
 
-  virtual int CurrentLayerId() const = 0;
+  virtual int GetTemporalLayerId(
+      TemporalLayers::FrameConfig tl_config) const = 0;
 };
 
 class TemporalLayersListener;