1 files changed, 146 insertions, 0 deletions
diff --git a/third_party/libwebrtc/modules/video_coding/codecs/vp8/temporal_layers_checker.cc b/third_party/libwebrtc/modules/video_coding/codecs/vp8/temporal_layers_checker.cc
new file mode 100644
index 0000000000..5aebd2c526
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/codecs/vp8/temporal_layers_checker.cc
@@ -0,0 +1,146 @@
+/*
+ *  Copyright (c) 2018 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.
+ */
+
+#include "modules/video_coding/codecs/vp8/include/temporal_layers_checker.h"
+
+#include <memory>
+
+#include "modules/video_coding/codecs/interface/common_constants.h"
+#include "modules/video_coding/codecs/vp8/default_temporal_layers.h"
+#include "rtc_base/logging.h"
+
+namespace webrtc {
+
+std::unique_ptr<TemporalLayersChecker>
+TemporalLayersChecker::CreateTemporalLayersChecker(Vp8TemporalLayersType type,
+                                                   int num_temporal_layers) {
+  switch (type) {
+    case Vp8TemporalLayersType::kFixedPattern:
+      return std::make_unique<DefaultTemporalLayersChecker>(
+          num_temporal_layers);
+    case Vp8TemporalLayersType::kBitrateDynamic:
+      // Conference mode temporal layering for screen content in base stream.
+      return std::make_unique<TemporalLayersChecker>(num_temporal_layers);
+  }
+  RTC_CHECK_NOTREACHED();
+}
+
+TemporalLayersChecker::TemporalLayersChecker(int num_temporal_layers)
+    : num_temporal_layers_(num_temporal_layers),
+      sequence_number_(0),
+      last_sync_sequence_number_(0),
+      last_tl0_sequence_number_(0) {}
+
+bool TemporalLayersChecker::CheckAndUpdateBufferState(
+    BufferState* state,
+    bool* need_sync,
+    bool frame_is_keyframe,
+    uint8_t temporal_layer,
+    Vp8FrameConfig::BufferFlags flags,
+    uint32_t sequence_number,
+    uint32_t* lowest_sequence_referenced) {
+  if (flags & Vp8FrameConfig::BufferFlags::kReference) {
+    if (state->temporal_layer > 0 && !state->is_keyframe) {
+      *need_sync = false;
+    }
+    if (!state->is_keyframe && !frame_is_keyframe &&
+        state->sequence_number < *lowest_sequence_referenced) {
+      *lowest_sequence_referenced = state->sequence_number;
+    }
+    if (!frame_is_keyframe && !state->is_keyframe &&
+        state->temporal_layer > temporal_layer) {
+      RTC_LOG(LS_ERROR) << "Frame is referencing higher temporal layer.";
+      return false;
+    }
+  }
+  if ((flags & Vp8FrameConfig::BufferFlags::kUpdate)) {
+    state->temporal_layer = temporal_layer;
+    state->sequence_number = sequence_number;
+    state->is_keyframe = frame_is_keyframe;
+  }
+  if (frame_is_keyframe)
+    state->is_keyframe = true;
+  return true;
+}
+
+bool TemporalLayersChecker::CheckTemporalConfig(
+    bool frame_is_keyframe,
+    const Vp8FrameConfig& frame_config) {
+  if (frame_config.drop_frame ||
+      frame_config.packetizer_temporal_idx == kNoTemporalIdx) {
+    return true;
+  }
+  ++sequence_number_;
+  if (frame_config.packetizer_temporal_idx >= num_temporal_layers_ ||
+      (frame_config.packetizer_temporal_idx == kNoTemporalIdx &&
+       num_temporal_layers_ > 1)) {
+    RTC_LOG(LS_ERROR) << "Incorrect temporal layer set for frame: "
+                      << frame_config.packetizer_temporal_idx
+                      << " num_temporal_layers: " << num_temporal_layers_;
+    return false;
+  }
+
+  uint32_t lowest_sequence_referenced = sequence_number_;
+  bool need_sync = frame_config.packetizer_temporal_idx > 0 &&
+                   frame_config.packetizer_temporal_idx != kNoTemporalIdx;
+
+  if (!CheckAndUpdateBufferState(
+          &last_, &need_sync, frame_is_keyframe,
+          frame_config.packetizer_temporal_idx, frame_config.last_buffer_flags,
+          sequence_number_, &lowest_sequence_referenced)) {
+    RTC_LOG(LS_ERROR) << "Error in the Last buffer";
+    return false;
+  }
+  if (!CheckAndUpdateBufferState(&golden_, &need_sync, frame_is_keyframe,
+                                 frame_config.packetizer_temporal_idx,
+                                 frame_config.golden_buffer_flags,
+                                 sequence_number_,
+                                 &lowest_sequence_referenced)) {
+    RTC_LOG(LS_ERROR) << "Error in the Golden buffer";
+    return false;
+  }
+  if (!CheckAndUpdateBufferState(
+          &arf_, &need_sync, frame_is_keyframe,
+          frame_config.packetizer_temporal_idx, frame_config.arf_buffer_flags,
+          sequence_number_, &lowest_sequence_referenced)) {
+    RTC_LOG(LS_ERROR) << "Error in the Arf buffer";
+    return false;
+  }
+
+  if (lowest_sequence_referenced < last_sync_sequence_number_ &&
+      !frame_is_keyframe) {
+    RTC_LOG(LS_ERROR) << "Reference past the last sync frame. Referenced "
+                      << lowest_sequence_referenced << ", but sync was at "
+                      << last_sync_sequence_number_;
+    return false;
+  }
+
+  if (frame_config.packetizer_temporal_idx == 0) {
+    last_tl0_sequence_number_ = sequence_number_;
+  }
+
+  if (frame_is_keyframe) {
+    last_sync_sequence_number_ = sequence_number_;
+  }
+
+  if (need_sync) {
+    last_sync_sequence_number_ = last_tl0_sequence_number_;
+  }
+
+  // Ignore sync flag on key-frames as it really doesn't matter.
+  if (need_sync != frame_config.layer_sync && !frame_is_keyframe) {
+    RTC_LOG(LS_ERROR) << "Sync bit is set incorrectly on a frame. Expected: "
+                      << need_sync << " Actual: " << frame_config.layer_sync;
+    return false;
+  }
+  return true;
+}
+
+}  // namespace webrtc