mirror of
https://github.com/ZLMediaKit/ZLMediaKit.git
synced 2024-11-22 19:00:01 +08:00
200 lines
7.3 KiB
C++
200 lines
7.3 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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#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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map<uint8_t/*id*/, RtpExt/*data*/> RtpExt::getExtValue(const RtpHeader *header, const RtcMedia &media) {
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map<uint8_t, 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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RtpExtType type;
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if (reserved == kOneByteHeader) {
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while (ptr < end) {
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RtpExtOneByte *ext = reinterpret_cast<RtpExtOneByte *>(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) + RtpExtOneByte::kMinSize <= end);
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CHECK(ext->getData() + ext->getSize() <= end);
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ret.emplace(ext->getId(), RtpExt(type, reinterpret_cast<char *>(ext->getData()), ext->getSize()));
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ptr += RtpExtOneByte::kMinSize + ext->getSize();
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}
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return ret;
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}
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if ((reserved & 0xFFF0) >> 4 == kTwoByteHeader) {
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while (ptr < end) {
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RtpExtTwoByte *ext = reinterpret_cast<RtpExtTwoByte *>(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) + RtpExtTwoByte::kMinSize <= end);
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CHECK(ext->getData() + ext->getSize() <= end);
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ret.emplace(ext->getId(), RtpExt(type, reinterpret_cast<char *>(ext->getData()), ext->getSize()));
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ptr += RtpExtTwoByte::kMinSize + ext->getSize();
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}
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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(RtpExtType::ssrc_audio_level, "urn:ietf:params:rtp-hdrext:ssrc-audio-level") \
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XX(RtpExtType::abs_send_time, "http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time") \
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XX(RtpExtType::transport_cc, "http://www.ietf.org/id/draft-holmer-rmcat-transport-wide-cc-extensions-01") \
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XX(RtpExtType::sdes_mid, "urn:ietf:params:rtp-hdrext:sdes:mid") \
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XX(RtpExtType::sdes_rtp_stream_id, "urn:ietf:params:rtp-hdrext:sdes:rtp-stream-id") \
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XX(RtpExtType::sdes_repaired_rtp_stream_id, "urn:ietf:params:rtp-hdrext:sdes:repaired-rtp-stream-id") \
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XX(RtpExtType::video_timing, "http://www.webrtc.org/experiments/rtp-hdrext/video-timing") \
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XX(RtpExtType::color_space, "http://www.webrtc.org/experiments/rtp-hdrext/color-space") \
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XX(RtpExtType::video_content_type, "http://www.webrtc.org/experiments/rtp-hdrext/video-content-type") \
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XX(RtpExtType::playout_delay, "http://www.webrtc.org/experiments/rtp-hdrext/playout-delay") \
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XX(RtpExtType::video_orientation, "urn:3gpp:video-orientation") \
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XX(RtpExtType::toffset, "urn:ietf:params:rtp-hdrext:toffset")
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#define XX(type, url) {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, 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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