|  | /* | 
|  | *  Copyright (c) 2015 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 "webrtc/modules/rtp_rtcp/source/rtcp_packet/rtpfb.h" | 
|  |  | 
|  | #include "webrtc/modules/rtp_rtcp/source/byte_io.h" | 
|  |  | 
|  | namespace webrtc { | 
|  | namespace rtcp { | 
|  | constexpr uint8_t Rtpfb::kPacketType; | 
|  | // RFC 4585, Section 6.1: Feedback format. | 
|  | // | 
|  | // Common packet format: | 
|  | // | 
|  | //    0                   1                   2                   3 | 
|  | //    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 | 
|  | //   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 
|  | //   |V=2|P|   FMT   |       PT      |          length               | | 
|  | //   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 
|  | // 0 |                  SSRC of packet sender                        | | 
|  | //   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 
|  | // 4 |                  SSRC of media source                         | | 
|  | //   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 
|  | //   :            Feedback Control Information (FCI)                 : | 
|  | //   :                                                               : | 
|  |  | 
|  | void Rtpfb::ParseCommonFeedback(const uint8_t* payload) { | 
|  | sender_ssrc_ = ByteReader<uint32_t>::ReadBigEndian(&payload[0]); | 
|  | media_ssrc_ = ByteReader<uint32_t>::ReadBigEndian(&payload[4]); | 
|  | } | 
|  |  | 
|  | void Rtpfb::CreateCommonFeedback(uint8_t* payload) const { | 
|  | ByteWriter<uint32_t>::WriteBigEndian(&payload[0], sender_ssrc_); | 
|  | ByteWriter<uint32_t>::WriteBigEndian(&payload[4], media_ssrc_); | 
|  | } | 
|  |  | 
|  | }  // namespace rtcp | 
|  | }  // namespace webrtc |