mirror of
https://github.com/ZLMediaKit/ZLMediaKit.git
synced 2024-10-31 00:37:39 +08:00
501 lines
20 KiB
C++
501 lines
20 KiB
C++
/*
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* Copyright (c) 2016 The ZLMediaKit project authors. All Rights Reserved.
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*
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* This file is part of ZLMediaKit(https://github.com/xia-chu/ZLMediaKit).
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*
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* Use of this source code is governed by MIT license that can be found in the
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* LICENSE file in the root of the source tree. All contributing project authors
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* may be found in the AUTHORS file in the root of the source tree.
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*/
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#include "RtpExt.h"
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#include "Sdp.h"
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#if defined(_WIN32)
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#pragma pack(push, 1)
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#endif // defined(_WIN32)
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//https://tools.ietf.org/html/draft-holmer-rmcat-transport-wide-cc-extensions-01
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//https://tools.ietf.org/html/rfc5285
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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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// | 0xBE | 0xDE | length=3 |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// | ID | L=0 | data | ID | L=1 | data...
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// ...data | 0 (pad) | 0 (pad) | ID | L=3 |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// | data |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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class RtpExtOneByte {
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public:
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static constexpr uint16_t kMinSize = 1;
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size_t getSize() const;
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uint8_t getId() const;
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uint8_t* getData();
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private:
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#if __BYTE_ORDER == __BIG_ENDIAN
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uint8_t id: 4;
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uint8_t len: 4;
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#else
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uint8_t len: 4;
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uint8_t id: 4;
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#endif
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uint8_t data[1];
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} PACKED;
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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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// | 0x100 |appbits| length=3 |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// | ID | L=0 | ID | L=1 |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// | data | 0 (pad) | ID | L=4 |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// | data |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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class RtpExtTwoByte {
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public:
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static constexpr uint16_t kMinSize = 2;
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size_t getSize() const;
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uint8_t getId() const;
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uint8_t* getData();
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private:
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uint8_t id;
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uint8_t len;
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uint8_t data[1];
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} PACKED;
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#if defined(_WIN32)
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#pragma pack(pop)
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#endif // defined(_WIN32)
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//////////////////////////////////////////////////////////////////
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size_t RtpExtOneByte::getSize() const {
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return len + 1;
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}
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uint8_t RtpExtOneByte::getId() const {
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return id;
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}
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uint8_t *RtpExtOneByte::getData() {
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return data;
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}
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//////////////////////////////////////////////////////////////////
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size_t RtpExtTwoByte::getSize() const {
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return len;
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}
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uint8_t RtpExtTwoByte::getId() const {
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return id;
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}
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uint8_t *RtpExtTwoByte::getData() {
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return data;
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}
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//////////////////////////////////////////////////////////////////
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static constexpr uint16_t kOneByteHeader = 0xBEDE;
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static constexpr uint16_t kTwoByteHeader = 0x1000;
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static RtpExtType getExtTypeById(uint8_t id, const RtcMedia &media){
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auto it = media.extmap.find(id);
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if (it == media.extmap.end()) {
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return RtpExtType::padding;
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}
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return RtpExt::getExtType(it->second.ext);
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}
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template<typename Type>
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static void appendExt( map<RtpExtType, RtpExt> &ret,const RtcMedia &media, uint8_t *ptr, const uint8_t *end){
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while (ptr < end) {
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auto ext = reinterpret_cast<Type *>(ptr);
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if (ext->getId() == (uint8_t) RtpExtType::padding) {
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//padding，忽略
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++ptr;
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continue;
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}
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//15类型的rtp ext为保留
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CHECK(ext->getId() < (uint8_t) RtpExtType::reserved);
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CHECK(reinterpret_cast<uint8_t *>(ext) + Type::kMinSize <= end);
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CHECK(ext->getData() + ext->getSize() <= end);
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auto type = getExtTypeById(ext->getId(), media);
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ret.emplace(type, RtpExt(type, ext->getId(), reinterpret_cast<char *>(ext->getData()), ext->getSize()));
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ptr += Type::kMinSize + ext->getSize();
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}
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}
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map<RtpExtType/*type*/, RtpExt/*data*/> RtpExt::getExtValue(const RtpHeader *header, const RtcMedia &media) {
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map<RtpExtType, RtpExt> ret;
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assert(header);
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auto ext_size = header->getExtSize();
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if (!ext_size) {
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return ret;
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}
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auto reserved = header->getExtReserved();
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auto ptr = const_cast<RtpHeader *>(header)->getExtData();
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auto end = ptr + ext_size;
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if (reserved == kOneByteHeader) {
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appendExt<RtpExtOneByte>(ret, media, ptr, end);
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return ret;
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}
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if ((reserved & 0xFFF0) >> 4 == kTwoByteHeader) {
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appendExt<RtpExtTwoByte>(ret, media, ptr, end);
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return ret;
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}
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return ret;
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}
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#define RTP_EXT_MAP(XX) \
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XX(ssrc_audio_level, "urn:ietf:params:rtp-hdrext:ssrc-audio-level") \
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XX(abs_send_time, "http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time") \
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XX(transport_cc, "http://www.ietf.org/id/draft-holmer-rmcat-transport-wide-cc-extensions-01") \
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XX(sdes_mid, "urn:ietf:params:rtp-hdrext:sdes:mid") \
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XX(sdes_rtp_stream_id, "urn:ietf:params:rtp-hdrext:sdes:rtp-stream-id") \
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XX(sdes_repaired_rtp_stream_id, "urn:ietf:params:rtp-hdrext:sdes:repaired-rtp-stream-id") \
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XX(video_timing, "http://www.webrtc.org/experiments/rtp-hdrext/video-timing") \
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XX(color_space, "http://www.webrtc.org/experiments/rtp-hdrext/color-space") \
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XX(csrc_audio_level, "urn:ietf:params:rtp-hdrext:csrc-audio-level") \
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XX(framemarking, "http://tools.ietf.org/html/draft-ietf-avtext-framemarking-07") \
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XX(video_content_type, "http://www.webrtc.org/experiments/rtp-hdrext/video-content-type") \
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XX(playout_delay, "http://www.webrtc.org/experiments/rtp-hdrext/playout-delay") \
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XX(video_orientation, "urn:3gpp:video-orientation") \
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XX(toffset, "urn:ietf:params:rtp-hdrext:toffset") \
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XX(encrypt, "urn:ietf:params:rtp-hdrext:encrypt")
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#define XX(type, url) {RtpExtType::type , url},
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static unordered_map<RtpExtType/*id*/, string/*ext*/> s_type_to_url = {RTP_EXT_MAP(XX)};
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#undef XX
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#define XX(type, url) {url, RtpExtType::type},
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static unordered_map<string/*ext*/, RtpExtType/*id*/> s_url_to_type = {RTP_EXT_MAP(XX)};
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#undef XX
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RtpExtType RtpExt::getExtType(const string &url) {
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auto it = s_url_to_type.find(url);
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if (it == s_url_to_type.end()) {
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throw std::invalid_argument(string("未识别的rtp ext url类型:") + url);
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}
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return it->second;
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}
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const string &RtpExt::getExtUrl(RtpExtType type) {
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auto it = s_type_to_url.find(type);
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if (it == s_type_to_url.end()) {
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throw std::invalid_argument(string("未识别的rtp ext类型:") + to_string((int) type));
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}
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return it->second;
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}
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const char *RtpExt::getExtName(RtpExtType type) {
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#define XX(type, url) case RtpExtType::type: return #type;
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switch (type) {
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RTP_EXT_MAP(XX)
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default: return "unknown ext type";
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}
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#undef XX
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}
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string RtpExt::dumpString() const {
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_StrPrinter printer;
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switch (_type) {
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case RtpExtType::ssrc_audio_level : {
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bool vad;
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printer << "audio level:" << (int) getAudioLevel(&vad) << ", vad:" << vad;
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break;
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}
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case RtpExtType::abs_send_time : {
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printer << "abs send time:" << getAbsSendTime();
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break;
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}
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case RtpExtType::transport_cc : {
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printer << "twcc seq:" << getTransportCCSeq();
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break;
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}
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case RtpExtType::sdes_mid : {
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printer << "sdes mid:" << getSdesMid();
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break;
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}
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case RtpExtType::sdes_rtp_stream_id : {
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printer << "rtp stream id:" << getRtpStreamId();
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break;
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}
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case RtpExtType::sdes_repaired_rtp_stream_id : {
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printer << "rtp repaired stream id:" << getRepairedRtpStreamId();
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break;
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}
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case RtpExtType::video_timing : {
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uint8_t flags;
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uint16_t encode_start, encode_finish, packetization_complete, last_pkt_left_pacer, reserved_net0, reserved_net1;
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getVideoTiming(flags, encode_start, encode_finish, packetization_complete, last_pkt_left_pacer,
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reserved_net0, reserved_net1);
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printer << "video timing, flags:" << (int) flags
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<< ",encode:" << encode_start << "-" << encode_finish
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<< ",packetization_complete:" << packetization_complete
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<< ",last_pkt_left_pacer:" << last_pkt_left_pacer
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<< ",reserved_net0:" << reserved_net0
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<< ",reserved_net1:" << reserved_net1;
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break;
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}
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case RtpExtType::video_content_type : {
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printer << "video content type:" << (int)getVideoContentType();
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break;
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}
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case RtpExtType::video_orientation : {
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bool camera_bit, flip_bit, first_rotation, second_rotation;
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getVideoOrientation(camera_bit, flip_bit, first_rotation, second_rotation);
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printer << "video orientation:" << camera_bit << "-" << flip_bit << "-" << first_rotation << "-" << second_rotation;
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break;
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}
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case RtpExtType::playout_delay : {
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uint16_t min_delay, max_delay;
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getPlayoutDelay(min_delay, max_delay);
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printer << "playout delay:" << min_delay << "-" << max_delay;
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break;
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}
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case RtpExtType::toffset : {
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printer << "toffset:" << getTransmissionOffset();
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break;
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}
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case RtpExtType::framemarking : {
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printer << "framemarking tid:" << getFramemarkingTID();
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break;
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}
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default: {
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printer << getExtName(_type) << ", id:" << (int) _id << ", ";
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printer << "hex:" << hexdump(data(), size());
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break;
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}
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}
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return std::move(printer);
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}
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//https://tools.ietf.org/html/rfc6464
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// 0 1
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// 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// | ID | len=0 |V| level |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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//
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// Figure 1: Sample Audio Level Encoding Using the
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// One-Byte Header Format
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//
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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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// | ID | len=1 |V| level | 0 (pad) |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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//
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// Figure 2: Sample Audio Level Encoding Using the
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// Two-Byte Header Format
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uint8_t RtpExt::getAudioLevel(bool *vad) const{
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CHECK(_type == RtpExtType::ssrc_audio_level && size() >= 1);
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auto &byte = (*this)[0];
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if (vad) {
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*vad = byte & 0x80;
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}
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return byte & 0x7F;
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}
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//http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time
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//Wire format: 1-byte extension, 3 bytes of data. total 4 bytes extra per packet (plus shared 4 bytes for all extensions present: 2 byte magic word 0xBEDE, 2 byte # of extensions). Will in practice replace the “toffset” extension so we should see no long term increase in traffic as a result.
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//
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//Encoding: Timestamp is in seconds, 24 bit 6.18 fixed point, yielding 64s wraparound and 3.8us resolution (one increment for each 477 bytes going out on a 1Gbps interface).
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//
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//Relation to NTP timestamps: abs_send_time_24 = (ntp_timestamp_64 >> 14) & 0x00ffffff ; NTP timestamp is 32 bits for whole seconds, 32 bits fraction of second.
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//
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//Notes: Packets are time stamped when going out, preferably close to metal. Intermediate RTP relays (entities possibly altering the stream) should remove the extension or set its own timestamp.
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uint32_t RtpExt::getAbsSendTime() const {
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CHECK(_type == RtpExtType::abs_send_time && size() >= 3);
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uint32_t ret = 0;
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ret |= (*this)[0] << 16;
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ret |= (*this)[1] << 8;
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ret |= (*this)[2];
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return ret;
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}
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//https://tools.ietf.org/html/draft-holmer-rmcat-transport-wide-cc-extensions-01
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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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// | 0xBE | 0xDE | length=1 |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// | ID | L=1 |transport-wide sequence number | zero padding |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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uint16_t RtpExt::getTransportCCSeq() const {
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CHECK(_type == RtpExtType::transport_cc && size() >= 2);
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uint16_t ret;
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ret |= (*this)[0] << 8;
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ret |= (*this)[1];
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return ret;
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}
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//https://tools.ietf.org/html/draft-ietf-avtext-sdes-hdr-ext-07
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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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// | ID | len | SDES Item text value ... |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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const string &RtpExt::getSdesMid() const {
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CHECK(_type == RtpExtType::sdes_mid && size() >= 1);
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return *this;
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}
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//https://tools.ietf.org/html/draft-ietf-avtext-rid-06
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//用于simulecast
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//3.1. RTCP 'RtpStreamId' SDES Extension
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//
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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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// |RtpStreamId=TBD| length | RtpStreamId ...
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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//
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//
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// The RtpStreamId payload is UTF-8 encoded and is not null-terminated.
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//
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// RFC EDITOR NOTE: Please replace TBD with the assigned SDES
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// identifier value.
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//3.2. RTCP 'RepairedRtpStreamId' SDES Extension
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//
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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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// |Repaired...=TBD| length | RepairRtpStreamId ...
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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//
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//
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// The RepairedRtpStreamId payload is UTF-8 encoded and is not null-
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// terminated.
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//
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// RFC EDITOR NOTE: Please replace TBD with the assigned SDES
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// identifier value.
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string RtpExt::getRtpStreamId() const {
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CHECK(_type == RtpExtType::sdes_rtp_stream_id && size() >= 1);
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return *this;
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}
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string RtpExt::getRepairedRtpStreamId() const {
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CHECK(_type == RtpExtType::sdes_repaired_rtp_stream_id && size() >= 1);
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return *this;
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}
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//http://www.webrtc.org/experiments/rtp-hdrext/video-timing
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//Wire format: 1-byte extension, 13 bytes of data. Total 14 bytes extra per packet (plus 1-3 padding byte in some cases, plus shared 4 bytes for all extensions present: 2 byte magic word 0xBEDE, 2 byte # of extensions).
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//
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//First byte is a flags field. Defined flags:
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//
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//0x01 - extension is set due to timer.
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//0x02 - extension is set because the frame is larger than usual.
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//Both flags may be set at the same time. All remaining 6 bits are reserved and should be ignored.
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//
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//Next, 6 timestamps are stored as 16-bit values in big-endian order, representing delta from the capture time of a packet in ms. Timestamps are, in order:
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//
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//Encode start.
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//Encode finish.
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//Packetization complete.
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//Last packet left the pacer.
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//Reserved for network.
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//Reserved for network (2).
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void RtpExt::getVideoTiming(uint8_t &flags,
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uint16_t &encode_start,
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uint16_t &encode_finish,
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uint16_t &packetization_complete,
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uint16_t &last_pkt_left_pacer,
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uint16_t &reserved_net0,
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uint16_t &reserved_net1) const {
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CHECK(_type == RtpExtType::video_timing && size() >= 13);
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flags = (*this)[0];
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encode_start = (*this)[1] << 8 | (*this)[2];
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encode_finish = (*this)[3] << 8 | (*this)[4];
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packetization_complete = (*this)[5] << 8 | (*this)[6];
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last_pkt_left_pacer = (*this)[7] << 8 | (*this)[8];
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reserved_net0 = (*this)[9] << 8 | (*this)[10];
|
||
reserved_net1 = (*this)[11] << 8 | (*this)[12];
|
||
}
|
||
|
||
|
||
//http://www.webrtc.org/experiments/rtp-hdrext/color-space
|
||
// 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
|
||
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
||
// | ID | L = 3 | primaries | transfer | matrix |
|
||
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
||
// |range+chr.sit. |
|
||
// +-+-+-+-+-+-+-+-+
|
||
|
||
|
||
//http://www.webrtc.org/experiments/rtp-hdrext/video-content-type
|
||
//Values:
|
||
//0x00: Unspecified. Default value. Treated the same as an absence of an extension.
|
||
//0x01: Screenshare. Video stream is of a screenshare type.
|
||
//0x02: 摄像头？
|
||
//Notes: Extension shoud be present only in the last packet of key-frames.
|
||
// If attached to other packets it should be ignored.
|
||
// If extension is absent, Unspecified value is assumed.
|
||
uint8_t RtpExt::getVideoContentType() const {
|
||
CHECK(_type == RtpExtType::video_content_type && size() >= 1);
|
||
return (*this)[0];
|
||
}
|
||
|
||
//http://www.3gpp.org/ftp/Specs/html-info/26114.htm
|
||
void RtpExt::getVideoOrientation(bool &camera_bit, bool &flip_bit, bool &first_rotation, bool &second_rotation) const {
|
||
CHECK(_type == RtpExtType::video_orientation && size() >= 1);
|
||
uint8_t byte = (*this)[0];
|
||
camera_bit = (byte & 0x08) >> 3;
|
||
flip_bit = (byte & 0x04) >> 2;
|
||
first_rotation = (byte & 0x02) >> 1;
|
||
second_rotation = byte & 0x01;
|
||
}
|
||
|
||
//http://www.webrtc.org/experiments/rtp-hdrext/playout-delay
|
||
// 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
|
||
//+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
||
//| ID | len=2 | MIN delay | MAX delay |
|
||
//+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
||
void RtpExt::getPlayoutDelay(uint16_t &min_delay, uint16_t &max_delay) const {
|
||
CHECK(_type == RtpExtType::playout_delay && size() >= 3);
|
||
uint32_t bytes = (*this)[0] << 16 | (*this)[1] << 8 | (*this)[2];
|
||
min_delay = (bytes & 0x00FFF000) >> 12;
|
||
max_delay = bytes & 0x00000FFF;
|
||
}
|
||
|
||
//urn:ietf:params:rtp-hdrext:toffset
|
||
//https://tools.ietf.org/html/rfc5450
|
||
// 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
|
||
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
||
// | ID | len=2 | transmission offset |
|
||
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
||
uint32_t RtpExt::getTransmissionOffset() const {
|
||
CHECK(_type == RtpExtType::toffset && size() >= 3);
|
||
return (*this)[0] << 16 | (*this)[1] << 8 | (*this)[2];
|
||
}
|
||
|
||
//http://tools.ietf.org/html/draft-ietf-avtext-framemarking-07
|
||
// 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
|
||
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
||
// | ID=? | L=2 |S|E|I|D|B| TID | LID | TL0PICIDX |
|
||
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
||
uint8_t RtpExt::getFramemarkingTID() const {
|
||
CHECK(_type == RtpExtType::framemarking && size() >= 3);
|
||
return (*this)[0] & 0x07;
|
||
}
|