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diff --git a/third_party/libwebrtc/modules/video_coding/decoding_state.cc b/third_party/libwebrtc/modules/video_coding/decoding_state.cc
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+++ b/third_party/libwebrtc/modules/video_coding/decoding_state.cc
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+/*
+ * 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.
+ */
+
+#include "modules/video_coding/decoding_state.h"
+
+#include "common_video/h264/h264_common.h"
+#include "modules/include/module_common_types_public.h"
+#include "modules/video_coding/frame_buffer.h"
+#include "modules/video_coding/jitter_buffer_common.h"
+#include "modules/video_coding/packet.h"
+#include "rtc_base/logging.h"
+
+namespace webrtc {
+
+VCMDecodingState::VCMDecodingState()
+ : sequence_num_(0),
+ time_stamp_(0),
+ picture_id_(kNoPictureId),
+ temporal_id_(kNoTemporalIdx),
+ tl0_pic_id_(kNoTl0PicIdx),
+ full_sync_(true),
+ in_initial_state_(true) {
+ memset(frame_decoded_, 0, sizeof(frame_decoded_));
+}
+
+VCMDecodingState::~VCMDecodingState() {}
+
+void VCMDecodingState::Reset() {
+ // TODO(mikhal): Verify - not always would want to reset the sync
+ sequence_num_ = 0;
+ time_stamp_ = 0;
+ picture_id_ = kNoPictureId;
+ temporal_id_ = kNoTemporalIdx;
+ tl0_pic_id_ = kNoTl0PicIdx;
+ full_sync_ = true;
+ in_initial_state_ = true;
+ memset(frame_decoded_, 0, sizeof(frame_decoded_));
+ received_sps_.clear();
+ received_pps_.clear();
+}
+
+uint32_t VCMDecodingState::time_stamp() const {
+ return time_stamp_;
+}
+
+uint16_t VCMDecodingState::sequence_num() const {
+ return sequence_num_;
+}
+
+bool VCMDecodingState::IsOldFrame(const VCMFrameBuffer* frame) const {
+ RTC_DCHECK(frame);
+ if (in_initial_state_)
+ return false;
+ return !IsNewerTimestamp(frame->Timestamp(), time_stamp_);
+}
+
+bool VCMDecodingState::IsOldPacket(const VCMPacket* packet) const {
+ RTC_DCHECK(packet);
+ if (in_initial_state_)
+ return false;
+ return !IsNewerTimestamp(packet->timestamp, time_stamp_);
+}
+
+void VCMDecodingState::SetState(const VCMFrameBuffer* frame) {
+ RTC_DCHECK(frame);
+ RTC_CHECK_GE(frame->GetHighSeqNum(), 0);
+ if (!UsingFlexibleMode(frame))
+ UpdateSyncState(frame);
+ sequence_num_ = static_cast<uint16_t>(frame->GetHighSeqNum());
+ time_stamp_ = frame->Timestamp();
+ picture_id_ = frame->PictureId();
+ temporal_id_ = frame->TemporalId();
+ tl0_pic_id_ = frame->Tl0PicId();
+
+ for (const NaluInfo& nalu : frame->GetNaluInfos()) {
+ if (nalu.type == H264::NaluType::kPps) {
+ if (nalu.pps_id < 0) {
+ RTC_LOG(LS_WARNING) << "Received pps without pps id.";
+ } else if (nalu.sps_id < 0) {
+ RTC_LOG(LS_WARNING) << "Received pps without sps id.";
+ } else {
+ received_pps_[nalu.pps_id] = nalu.sps_id;
+ }
+ } else if (nalu.type == H264::NaluType::kSps) {
+ if (nalu.sps_id < 0) {
+ RTC_LOG(LS_WARNING) << "Received sps without sps id.";
+ } else {
+ received_sps_.insert(nalu.sps_id);
+ }
+ }
+ }
+
+ if (UsingFlexibleMode(frame)) {
+ uint16_t frame_index = picture_id_ % kFrameDecodedLength;
+ if (in_initial_state_) {
+ frame_decoded_cleared_to_ = frame_index;
+ } else if (frame->FrameType() == VideoFrameType::kVideoFrameKey) {
+ memset(frame_decoded_, 0, sizeof(frame_decoded_));
+ frame_decoded_cleared_to_ = frame_index;
+ } else {
+ if (AheadOfFramesDecodedClearedTo(frame_index)) {
+ while (frame_decoded_cleared_to_ != frame_index) {
+ frame_decoded_cleared_to_ =
+ (frame_decoded_cleared_to_ + 1) % kFrameDecodedLength;
+ frame_decoded_[frame_decoded_cleared_to_] = false;
+ }
+ }
+ }
+ frame_decoded_[frame_index] = true;
+ }
+
+ in_initial_state_ = false;
+}
+
+void VCMDecodingState::CopyFrom(const VCMDecodingState& state) {
+ sequence_num_ = state.sequence_num_;
+ time_stamp_ = state.time_stamp_;
+ picture_id_ = state.picture_id_;
+ temporal_id_ = state.temporal_id_;
+ tl0_pic_id_ = state.tl0_pic_id_;
+ full_sync_ = state.full_sync_;
+ in_initial_state_ = state.in_initial_state_;
+ frame_decoded_cleared_to_ = state.frame_decoded_cleared_to_;
+ memcpy(frame_decoded_, state.frame_decoded_, sizeof(frame_decoded_));
+ received_sps_ = state.received_sps_;
+ received_pps_ = state.received_pps_;
+}
+
+bool VCMDecodingState::UpdateEmptyFrame(const VCMFrameBuffer* frame) {
+ bool empty_packet = frame->GetHighSeqNum() == frame->GetLowSeqNum();
+ if (in_initial_state_ && empty_packet) {
+ // Drop empty packets as long as we are in the initial state.
+ return true;
+ }
+ if ((empty_packet && ContinuousSeqNum(frame->GetHighSeqNum())) ||
+ ContinuousFrame(frame)) {
+ // Continuous empty packets or continuous frames can be dropped if we
+ // advance the sequence number.
+ sequence_num_ = frame->GetHighSeqNum();
+ time_stamp_ = frame->Timestamp();
+ return true;
+ }
+ return false;
+}
+
+void VCMDecodingState::UpdateOldPacket(const VCMPacket* packet) {
+ RTC_DCHECK(packet);
+ if (packet->timestamp == time_stamp_) {
+ // Late packet belonging to the last decoded frame - make sure we update the
+ // last decoded sequence number.
+ sequence_num_ = LatestSequenceNumber(packet->seqNum, sequence_num_);
+ }
+}
+
+void VCMDecodingState::SetSeqNum(uint16_t new_seq_num) {
+ sequence_num_ = new_seq_num;
+}
+
+bool VCMDecodingState::in_initial_state() const {
+ return in_initial_state_;
+}
+
+bool VCMDecodingState::full_sync() const {
+ return full_sync_;
+}
+
+void VCMDecodingState::UpdateSyncState(const VCMFrameBuffer* frame) {
+ if (in_initial_state_)
+ return;
+ if (frame->TemporalId() == kNoTemporalIdx ||
+ frame->Tl0PicId() == kNoTl0PicIdx) {
+ full_sync_ = true;
+ } else if (frame->FrameType() == VideoFrameType::kVideoFrameKey ||
+ frame->LayerSync()) {
+ full_sync_ = true;
+ } else if (full_sync_) {
+ // Verify that we are still in sync.
+ // Sync will be broken if continuity is true for layers but not for the
+ // other methods (PictureId and SeqNum).
+ if (UsingPictureId(frame)) {
+ // First check for a valid tl0PicId.
+ if (frame->Tl0PicId() - tl0_pic_id_ > 1) {
+ full_sync_ = false;
+ } else {
+ full_sync_ = ContinuousPictureId(frame->PictureId());
+ }
+ } else {
+ full_sync_ =
+ ContinuousSeqNum(static_cast<uint16_t>(frame->GetLowSeqNum()));
+ }
+ }
+}
+
+bool VCMDecodingState::ContinuousFrame(const VCMFrameBuffer* frame) const {
+ // Check continuity based on the following hierarchy:
+ // - Temporal layers (stop here if out of sync).
+ // - Picture Id when available.
+ // - Sequence numbers.
+ // Return true when in initial state.
+ // Note that when a method is not applicable it will return false.
+ RTC_DCHECK(frame);
+ // A key frame is always considered continuous as it doesn't refer to any
+ // frames and therefore won't introduce any errors even if prior frames are
+ // missing.
+ if (frame->FrameType() == VideoFrameType::kVideoFrameKey &&
+ HaveSpsAndPps(frame->GetNaluInfos())) {
+ return true;
+ }
+ // When in the initial state we always require a key frame to start decoding.
+ if (in_initial_state_)
+ return false;
+ if (ContinuousLayer(frame->TemporalId(), frame->Tl0PicId()))
+ return true;
+ // tl0picId is either not used, or should remain unchanged.
+ if (frame->Tl0PicId() != tl0_pic_id_)
+ return false;
+ // Base layers are not continuous or temporal layers are inactive.
+ // In the presence of temporal layers, check for Picture ID/sequence number
+ // continuity if sync can be restored by this frame.
+ if (!full_sync_ && !frame->LayerSync())
+ return false;
+ if (UsingPictureId(frame)) {
+ if (UsingFlexibleMode(frame)) {
+ return ContinuousFrameRefs(frame);
+ } else {
+ return ContinuousPictureId(frame->PictureId());
+ }
+ } else {
+ return ContinuousSeqNum(static_cast<uint16_t>(frame->GetLowSeqNum())) &&
+ HaveSpsAndPps(frame->GetNaluInfos());
+ }
+}
+
+bool VCMDecodingState::ContinuousPictureId(int picture_id) const {
+ int next_picture_id = picture_id_ + 1;
+ if (picture_id < picture_id_) {
+ // Wrap
+ if (picture_id_ >= 0x80) {
+ // 15 bits used for picture id
+ return ((next_picture_id & 0x7FFF) == picture_id);
+ } else {
+ // 7 bits used for picture id
+ return ((next_picture_id & 0x7F) == picture_id);
+ }
+ }
+ // No wrap
+ return (next_picture_id == picture_id);
+}
+
+bool VCMDecodingState::ContinuousSeqNum(uint16_t seq_num) const {
+ return seq_num == static_cast<uint16_t>(sequence_num_ + 1);
+}
+
+bool VCMDecodingState::ContinuousLayer(int temporal_id, int tl0_pic_id) const {
+ // First, check if applicable.
+ if (temporal_id == kNoTemporalIdx || tl0_pic_id == kNoTl0PicIdx)
+ return false;
+ // If this is the first frame to use temporal layers, make sure we start
+ // from base.
+ else if (tl0_pic_id_ == kNoTl0PicIdx && temporal_id_ == kNoTemporalIdx &&
+ temporal_id == 0)
+ return true;
+
+ // Current implementation: Look for base layer continuity.
+ if (temporal_id != 0)
+ return false;
+ return (static_cast<uint8_t>(tl0_pic_id_ + 1) == tl0_pic_id);
+}
+
+bool VCMDecodingState::ContinuousFrameRefs(const VCMFrameBuffer* frame) const {
+ uint8_t num_refs = frame->CodecSpecific()->codecSpecific.VP9.num_ref_pics;
+ for (uint8_t r = 0; r < num_refs; ++r) {
+ uint16_t frame_ref = frame->PictureId() -
+ frame->CodecSpecific()->codecSpecific.VP9.p_diff[r];
+ uint16_t frame_index = frame_ref % kFrameDecodedLength;
+ if (AheadOfFramesDecodedClearedTo(frame_index) ||
+ !frame_decoded_[frame_index]) {
+ return false;
+ }
+ }
+ return true;
+}
+
+bool VCMDecodingState::UsingPictureId(const VCMFrameBuffer* frame) const {
+ return (frame->PictureId() != kNoPictureId && picture_id_ != kNoPictureId);
+}
+
+bool VCMDecodingState::UsingFlexibleMode(const VCMFrameBuffer* frame) const {
+ bool is_flexible_mode =
+ frame->CodecSpecific()->codecType == kVideoCodecVP9 &&
+ frame->CodecSpecific()->codecSpecific.VP9.flexible_mode;
+ if (is_flexible_mode && frame->PictureId() == kNoPictureId) {
+ RTC_LOG(LS_WARNING) << "Frame is marked as using flexible mode but no"
+ "picture id is set.";
+ return false;
+ }
+ return is_flexible_mode;
+}
+
+// TODO(philipel): change how check work, this check practially
+// limits the max p_diff to 64.
+bool VCMDecodingState::AheadOfFramesDecodedClearedTo(uint16_t index) const {
+ // No way of knowing for sure if we are actually ahead of
+ // frame_decoded_cleared_to_. We just make the assumption
+ // that we are not trying to reference back to a very old
+ // index, but instead are referencing a newer index.
+ uint16_t diff =
+ index > frame_decoded_cleared_to_
+ ? kFrameDecodedLength - (index - frame_decoded_cleared_to_)
+ : frame_decoded_cleared_to_ - index;
+ return diff > kFrameDecodedLength / 2;
+}
+
+bool VCMDecodingState::HaveSpsAndPps(const std::vector<NaluInfo>& nalus) const {
+ std::set<int> new_sps;
+ std::map<int, int> new_pps;
+ for (const NaluInfo& nalu : nalus) {
+ // Check if this nalu actually contains sps/pps information or dependencies.
+ if (nalu.sps_id == -1 && nalu.pps_id == -1)
+ continue;
+ switch (nalu.type) {
+ case H264::NaluType::kPps:
+ if (nalu.pps_id < 0) {
+ RTC_LOG(LS_WARNING) << "Received pps without pps id.";
+ } else if (nalu.sps_id < 0) {
+ RTC_LOG(LS_WARNING) << "Received pps without sps id.";
+ } else {
+ new_pps[nalu.pps_id] = nalu.sps_id;
+ }
+ break;
+ case H264::NaluType::kSps:
+ if (nalu.sps_id < 0) {
+ RTC_LOG(LS_WARNING) << "Received sps without sps id.";
+ } else {
+ new_sps.insert(nalu.sps_id);
+ }
+ break;
+ default: {
+ int needed_sps = -1;
+ auto pps_it = new_pps.find(nalu.pps_id);
+ if (pps_it != new_pps.end()) {
+ needed_sps = pps_it->second;
+ } else {
+ auto pps_it2 = received_pps_.find(nalu.pps_id);
+ if (pps_it2 == received_pps_.end()) {
+ return false;
+ }
+ needed_sps = pps_it2->second;
+ }
+ if (new_sps.find(needed_sps) == new_sps.end() &&
+ received_sps_.find(needed_sps) == received_sps_.end()) {
+ return false;
+ }
+ break;
+ }
+ }
+ }
+ return true;
+}
+
+} // namespace webrtc