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dfd5c4b15e
Bug: webrtc:10312 Change-Id: I1b24e23f8002feef8a2ef928130ac6da19c3cd81 Reviewed-on: https://webrtc-review.googlesource.com/c/122580 Reviewed-by: Danil Chapovalov <danilchap@webrtc.org> Reviewed-by: Mirta Dvornicic <mirtad@webrtc.org> Commit-Queue: Björn Terelius <terelius@webrtc.org> Cr-Commit-Position: refs/heads/master@{#26670}
113 lines
4.3 KiB
C++
113 lines
4.3 KiB
C++
/*
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* Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#include "modules/rtp_rtcp/source/rtcp_packet/fir.h"
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#include "modules/rtp_rtcp/source/byte_io.h"
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#include "modules/rtp_rtcp/source/rtcp_packet/common_header.h"
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#include "rtc_base/checks.h"
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#include "rtc_base/logging.h"
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namespace webrtc {
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namespace rtcp {
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constexpr uint8_t Fir::kFeedbackMessageType;
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// RFC 4585: Feedback format.
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// Common packet format:
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//
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// 0 1 2 3
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// 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// |V=2|P| FMT | PT | length |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// | SSRC of packet sender |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// | SSRC of media source (unused) = 0 |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// : Feedback Control Information (FCI) :
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// : :
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// Full intra request (FIR) (RFC 5104).
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// The Feedback Control Information (FCI) for the Full Intra Request
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// consists of one or more FCI entries.
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// FCI:
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// 0 1 2 3
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// 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// | SSRC |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// | Seq nr. | Reserved = 0 |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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Fir::Fir() = default;
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Fir::Fir(const Fir& fir) = default;
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Fir::~Fir() = default;
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bool Fir::Parse(const CommonHeader& packet) {
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RTC_DCHECK_EQ(packet.type(), kPacketType);
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RTC_DCHECK_EQ(packet.fmt(), kFeedbackMessageType);
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// The FCI field MUST contain one or more FIR entries.
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if (packet.payload_size_bytes() < kCommonFeedbackLength + kFciLength) {
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RTC_LOG(LS_WARNING) << "Packet is too small to be a valid FIR packet.";
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return false;
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}
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if ((packet.payload_size_bytes() - kCommonFeedbackLength) % kFciLength != 0) {
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RTC_LOG(LS_WARNING) << "Invalid size for a valid FIR packet.";
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return false;
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}
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ParseCommonFeedback(packet.payload());
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size_t number_of_fci_items =
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(packet.payload_size_bytes() - kCommonFeedbackLength) / kFciLength;
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const uint8_t* next_fci = packet.payload() + kCommonFeedbackLength;
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items_.resize(number_of_fci_items);
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for (Request& request : items_) {
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request.ssrc = ByteReader<uint32_t>::ReadBigEndian(next_fci);
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request.seq_nr = ByteReader<uint8_t>::ReadBigEndian(next_fci + 4);
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next_fci += kFciLength;
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}
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return true;
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}
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size_t Fir::BlockLength() const {
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return kHeaderLength + kCommonFeedbackLength + kFciLength * items_.size();
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}
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bool Fir::Create(uint8_t* packet,
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size_t* index,
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size_t max_length,
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PacketReadyCallback callback) const {
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RTC_DCHECK(!items_.empty());
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while (*index + BlockLength() > max_length) {
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if (!OnBufferFull(packet, index, callback))
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return false;
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}
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size_t index_end = *index + BlockLength();
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CreateHeader(kFeedbackMessageType, kPacketType, HeaderLength(), packet,
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index);
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RTC_DCHECK_EQ(Psfb::media_ssrc(), 0);
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CreateCommonFeedback(packet + *index);
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*index += kCommonFeedbackLength;
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constexpr uint32_t kReserved = 0;
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for (const Request& request : items_) {
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ByteWriter<uint32_t>::WriteBigEndian(packet + *index, request.ssrc);
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ByteWriter<uint8_t>::WriteBigEndian(packet + *index + 4, request.seq_nr);
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ByteWriter<uint32_t, 3>::WriteBigEndian(packet + *index + 5, kReserved);
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*index += kFciLength;
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}
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RTC_CHECK_EQ(*index, index_end);
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return true;
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}
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} // namespace rtcp
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} // namespace webrtc
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