Derive current layer from TL frame config.

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

 /* Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */
 /*
 * This file defines the interface for doing temporal layers with VP8.
 */
 #ifndef WEBRTC_MODULES_VIDEO_CODING_CODECS_VP8_TEMPORAL_LAYERS_H_
 #define WEBRTC_MODULES_VIDEO_CODING_CODECS_VP8_TEMPORAL_LAYERS_H_
 
 #include <vector>
 
 #include "webrtc/common_video/include/video_image.h"
 #include "webrtc/typedefs.h"
 
 struct vpx_codec_enc_cfg;
 typedef struct vpx_codec_enc_cfg vpx_codec_enc_cfg_t;
 
 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.
   virtual std::vector<uint32_t> OnRatesUpdated(int bitrate_kbps,
                                                int max_bitrate_kbps,
                                                int framerate) = 0;
 
   // Update the encoder configuration with target bitrates or other parameters.
   // Returns true iff the configuration was actually modified.
   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;
 class TemporalLayersFactory {
  public:
   TemporalLayersFactory() : listener_(nullptr) {}
   virtual ~TemporalLayersFactory() {}
   virtual TemporalLayers* Create(int simulcast_id,
                                  int temporal_layers,
                                  uint8_t initial_tl0_pic_idx) const;
@@ skipping 17 matching lines @@
  public:
   TemporalLayersListener() {}
   virtual ~TemporalLayersListener() {}
 
   virtual void OnTemporalLayersCreated(int simulcast_id,
                                        TemporalLayers* layers) = 0;
 };
 
 }  // namespace webrtc
 #endif  // WEBRTC_MODULES_VIDEO_CODING_CODECS_VP8_TEMPORAL_LAYERS_H_