1 files changed, 64 insertions, 0 deletions
diff --git a/third_party/libwebrtc/modules/video_coding/svc/scalability_structure_l2t2_key_shift.h b/third_party/libwebrtc/modules/video_coding/svc/scalability_structure_l2t2_key_shift.h
new file mode 100644
index 0000000000..26d1afcb29
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/svc/scalability_structure_l2t2_key_shift.h
@@ -0,0 +1,64 @@
+/*
+ *  Copyright (c) 2020 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.
+ */
+#ifndef MODULES_VIDEO_CODING_SVC_SCALABILITY_STRUCTURE_L2T2_KEY_SHIFT_H_
+#define MODULES_VIDEO_CODING_SVC_SCALABILITY_STRUCTURE_L2T2_KEY_SHIFT_H_
+
+#include <vector>
+
+#include "api/transport/rtp/dependency_descriptor.h"
+#include "api/video/video_bitrate_allocation.h"
+#include "common_video/generic_frame_descriptor/generic_frame_info.h"
+#include "modules/video_coding/svc/scalable_video_controller.h"
+
+namespace webrtc {
+
+// S1T1     0   0
+//         /   /   /
+// S1T0   0---0---0
+//        |        ...
+// S0T1   |   0   0
+//        |  /   /
+// S0T0   0-0---0--
+// Time-> 0 1 2 3 4
+class ScalabilityStructureL2T2KeyShift : public ScalableVideoController {
+ public:
+  ~ScalabilityStructureL2T2KeyShift() override;
+
+  StreamLayersConfig StreamConfig() const override;
+  FrameDependencyStructure DependencyStructure() const override;
+
+  std::vector<LayerFrameConfig> NextFrameConfig(bool restart) override;
+  GenericFrameInfo OnEncodeDone(const LayerFrameConfig& config) override;
+  void OnRatesUpdated(const VideoBitrateAllocation& bitrates) override;
+
+ private:
+  enum FramePattern {
+    kKey,
+    kDelta0,
+    kDelta1,
+  };
+
+  static constexpr int kNumSpatialLayers = 2;
+  static constexpr int kNumTemporalLayers = 2;
+
+  bool DecodeTargetIsActive(int sid, int tid) const {
+    return active_decode_targets_[sid * kNumTemporalLayers + tid];
+  }
+  void SetDecodeTargetIsActive(int sid, int tid, bool value) {
+    active_decode_targets_.set(sid * kNumTemporalLayers + tid, value);
+  }
+
+  FramePattern next_pattern_ = kKey;
+  std::bitset<32> active_decode_targets_ = 0b1111;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_VIDEO_CODING_SVC_SCALABILITY_STRUCTURE_L2T2_KEY_SHIFT_H_