for rtc send can receive rtcp xr, player can calculate rtt , for metaRTC player send rtcp xr

src/Rtcp/Rtcp.cpp

@@ -193,7 +193,20 @@ void RtcpHeader::net2Host(size_t len) {
             bye->net2Host(len);
             break;
         }
-
+        case RtcpType::RTCP_XR:{
+             RtcpXRRRTR* xr = (RtcpXRRRTR*)this;
+             if(xr->bt == 4){
+                xr->net2Host(len);
+                //TraceL<<xr->dumpString();
+             }else if(xr->bt == 5){
+                RtcpXRDLRR* dlrr = (RtcpXRDLRR*)this;
+                dlrr->net2Host(len);
+                TraceL<<dlrr->dumpString();
+             }else{
+                throw std::runtime_error(StrPrinter << "rtcp xr bt " << xr->bt<<" not support");
+             }
+             break;
+        }
         default: throw std::runtime_error(StrPrinter << "未处理的rtcp包:" << rtcpTypeToStr((RtcpType) this->pt));
     }
 }
@@ -691,6 +704,98 @@ void RtcpBye::net2Host(size_t size) {
         }
     }
 }
+//////////////////////////////////////////// 
+string RtcpXRRRTR::dumpString() const {
+    _StrPrinter printer;
+    printer << RtcpHeader::dumpHeader();
+    printer << "ssrc :" <<ssrc<<"\r\n";
+    printer << "bt :" <<(int)bt<<"\r\n";
+    printer << "block_length : "<<block_length<<"\r\n";
+    printer << "ntp msw : "<<ntpmsw<<"\r\n";
+    printer << "ntp lsw : "<<ntplsw<<"\r\n";
+    return std::move(printer);
+}
+
+void RtcpXRRRTR::net2Host(size_t size) {
+    static const size_t kMinSize = sizeof(RtcpHeader);
+    CHECK_MIN_SIZE(size, kMinSize);
+    if(size != sizeof(RtcpXRRRTR)){
+        throw std::invalid_argument(StrPrinter << "rtcp xr Receiver Reference Time Report Block must is " << sizeof(RtcpXRRRTR)<<" actual size "<<size);
+    }
+    ssrc = ntohl(ssrc);
+    block_length = ntohs(block_length);
+    ntpmsw = ntohl(ntpmsw);
+    ntplsw = ntohl(ntplsw);
+}
+
+
+string RtcpXRDLRRReportItem::dumpString() const {
+    _StrPrinter printer;
+
+    printer << "ssrc :" <<ssrc<<"\r\n";
+    printer << "last RR (lrr) :" <<lrr<<"\r\n";
+    printer << "delay since last RR (dlrr): "<<dlrr<<"\r\n";
+    
+    return std::move(printer);
+}
+
+void RtcpXRDLRRReportItem::net2Host() {
+    ssrc = ntohl(ssrc);
+    lrr = ntohl(lrr);
+    dlrr = ntohl(dlrr);
+}
+
+std::vector<RtcpXRDLRRReportItem*> RtcpXRDLRR::getItemList(){
+    auto count = block_length/3;
+    RtcpXRDLRRReportItem *ptr = &items;
+    vector<RtcpXRDLRRReportItem *> ret;
+    for (int i = 0; i < (int) count; ++i) {
+        ret.emplace_back(ptr);
+        ++ptr;
+    }
+    return ret;
+
+}
+string RtcpXRDLRR::dumpString() const {
+    _StrPrinter printer;
+    printer << RtcpHeader::dumpHeader();
+    printer << "ssrc :" <<ssrc<<"\r\n";
+    printer << "bt :" <<(int)bt<<"\r\n";
+    printer << "block_length : "<<block_length<<"\r\n";
+    auto items_list = ((RtcpXRDLRR *) this)->getItemList();
+    auto i = 0;
+    for (auto &item : items_list) {
+        printer << "---- item:" << i++ << " ----\r\n";
+        printer << item->dumpString();
+    }
+    return std::move(printer);
+}
+
+void RtcpXRDLRR::net2Host(size_t size) {
+    static const size_t kMinSize = sizeof(RtcpHeader);
+    CHECK_MIN_SIZE(size, kMinSize);
+
+    ssrc = ntohl(ssrc);
+    block_length = ntohs(block_length);
+
+    auto count = block_length/3;
+    for (int i = 0; i < (int) count; ++i) {
+        RtcpXRDLRRReportItem *ptr = &items;
+        ptr->net2Host();
+        ptr++;
+    }
+}
+
+std::shared_ptr<RtcpXRDLRR>  RtcpXRDLRR::create(size_t item_count){
+    auto real_size = sizeof(RtcpXRDLRR) - sizeof(RtcpXRDLRRReportItem) + item_count * sizeof(RtcpXRDLRRReportItem);
+    auto bytes = alignSize(real_size);
+    auto ptr = (RtcpXRDLRR *) new char[bytes];
+    setupHeader(ptr, RtcpType::RTCP_XR, 0, bytes);
+    setupPadding(ptr, bytes - real_size);
+    return std::shared_ptr<RtcpXRDLRR>(ptr, [](RtcpXRDLRR *ptr) {
+        delete[] (char *) ptr;
+    });
+}
 
 #if 0
 #include "Util/onceToken.h"

src/Rtcp/Rtcp.h

@@ -687,6 +687,140 @@ private:
     void net2Host(size_t size);
 } PACKED;
 
+/*
+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|reserved |   PT=XR=207   |             length            |
++-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+|                              SSRC                             |
++-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+:                         report blocks                         :
++-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+*/
+/*
+
+    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
+   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+   |     BT=4      |   reserved    |       block length = 2        |
+   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+   |              NTP timestamp, most significant word             |
+   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+   |             NTP timestamp, least significant word             |
+   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+*/
+class RtcpXRRRTR : public RtcpHeader
+{
+public:
+    friend class RtcpHeader;
+    uint32_t ssrc;
+    // 4
+    uint8_t bt;
+    uint8_t reserved;
+    // 2
+    uint16_t block_length;
+     // ntp timestamp MSW(in second)
+    uint32_t ntpmsw;
+    // ntp timestamp LSW(in picosecond)
+    uint32_t ntplsw;
+private:
+     /**
+    * 打印字段详情
+    * 使用net2Host转换成主机字节序后才可使用此函数
+    */
+    std::string dumpString() const;
+
+    /**
+     * 网络字节序转换为主机字节序
+     * @param size 字节长度，防止内存越界
+     */
+    void net2Host(size_t size);
+
+}PACKED;
+
+/*
+
+  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
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ |     BT=5      |   reserved    |         block length          |
+ +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
+ |                 SSRC_1 (SSRC of first receiver)               | sub-
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ block
+ |                         last RR (LRR)                         |   1
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ |                   delay since last RR (DLRR)                  |
+ +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
+ |                 SSRC_2 (SSRC of second receiver)              | sub-
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ block
+ :                               ...                             :   2
+ +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
+*/
+class RtcpXRDLRRReportItem
+{
+public:
+    friend class RtcpXRDLRR;
+    uint32_t ssrc;
+    uint32_t lrr;
+    uint32_t dlrr;
+private:
+     /**
+    * 打印字段详情
+    * 使用net2Host转换成主机字节序后才可使用此函数
+    */
+    std::string dumpString() const;
+
+    /**
+     * 网络字节序转换为主机字节序
+     * @param size 字节长度，防止内存越界
+     */
+    void net2Host();
+}PACKED;
+
+
+
+class RtcpXRDLRR : public RtcpHeader
+{
+public:
+    friend class RtcpHeader;
+    uint32_t ssrc;
+    uint8_t bt;
+    uint8_t reserved;
+    uint16_t block_length;
+    RtcpXRDLRRReportItem items;
+
+    /**
+     * 创建RtcpXRDLRR包，只赋值了RtcpHeader部分(网络字节序)
+     * @param item_count RtcpXRDLRRReportItem对象个数
+     * @return RtcpXRDLRR包
+     */
+    static std::shared_ptr<RtcpXRDLRR> create(size_t item_count);
+
+     /**
+     * 获取RtcpXRDLRRReportItem对象指针列表
+     * 使用net2Host转换成主机字节序后才可使用此函数
+     */
+    std::vector<RtcpXRDLRRReportItem*> getItemList();
+
+private:
+     /**
+    * 打印字段详情
+    * 使用net2Host转换成主机字节序后才可使用此函数
+    */
+    std::string dumpString() const;
+
+    /**
+     * 网络字节序转换为主机字节序
+     * @param size 字节长度，防止内存越界
+     */
+    void net2Host(size_t size);
+
+}PACKED;
+
+
 #if defined(_WIN32)
 #pragma pack(pop)
 #endif // defined(_WIN32)

src/Rtcp/RtcpContext.cpp

@@ -45,6 +45,10 @@ Buffer::Ptr RtcpContext::createRtcpRR(uint32_t rtcp_ssrc, uint32_t rtp_ssrc) {
     throw std::runtime_error("没有实现, rtp发送者尝试发送rr包");
 }
 
+Buffer::Ptr RtcpContext::createRtcpXRDLRR(uint32_t rtcp_ssrc, uint32_t rtp_ssrc) {
+    throw std::runtime_error("没有实现, rtp发送者尝试发送xr dlrr包");
+}
+
 ////////////////////////////////////////////////////////////////////////////////////
 
 void RtcpContextForSend::onRtcp(RtcpHeader *rtcp) {
@@ -72,6 +76,18 @@ void RtcpContextForSend::onRtcp(RtcpHeader *rtcp) {
             }
             break;
         }
+        case RtcpType::RTCP_XR:{
+            auto rtcp_xr = (RtcpXRRRTR*)rtcp;
+            if(rtcp_xr->bt == 4){
+                _xr_xrrtr_recv_last_rr[rtcp_xr->ssrc] = ((rtcp_xr->ntpmsw & 0xFFFF) << 16) | ((rtcp_xr->ntplsw >> 16) & 0xFFFF);
+                _xr_rrtr_recv_sys_stamp[rtcp_xr->ssrc] = getCurrentMillisecond();
+            }else if(rtcp_xr->bt == 5){
+                TraceL<<"for sender not recive dlrr";
+            }else{
+                TraceL<<"not support xr bt "<<rtcp_xr->bt;
+            }
+            break;
+        }
         default: break;
     }
 }
@@ -103,6 +119,34 @@ Buffer::Ptr RtcpContextForSend::createRtcpSR(uint32_t rtcp_ssrc) {
     return RtcpHeader::toBuffer(std::move(rtcp));
 }
 
+toolkit::Buffer::Ptr RtcpContextForSend::createRtcpXRDLRR(uint32_t rtcp_ssrc, uint32_t rtp_ssrc){
+    auto rtcp = RtcpXRDLRR::create(1);
+    rtcp->bt = 5;
+    rtcp->reserved = 0;
+    rtcp->block_length = htons(3);
+    rtcp->ssrc = htonl(rtcp_ssrc);
+    rtcp->items.ssrc = htonl(rtp_ssrc);
+
+    if(_xr_xrrtr_recv_last_rr.find(rtp_ssrc) == _xr_xrrtr_recv_last_rr.end()){
+        rtcp->items.lrr = 0;
+        WarnL;
+    }else{
+        rtcp->items.lrr = htonl(_xr_xrrtr_recv_last_rr[rtp_ssrc]);
+    }
+
+    if(_xr_rrtr_recv_sys_stamp.find(rtp_ssrc)  ==  _xr_rrtr_recv_sys_stamp.end()){
+        rtcp->items.dlrr = 0;
+        WarnL;
+    } else {
+        // now - Last SR time,单位毫秒
+        auto delay = getCurrentMillisecond() - _xr_rrtr_recv_sys_stamp[rtp_ssrc];
+        // in units of 1/65536 seconds
+        auto dlsr = (uint32_t)(delay / 1000.0f * 65536);
+        rtcp->items.dlrr = htonl(dlsr);
+    }
+    return RtcpHeader::toBuffer(std::move(rtcp));
+}
+
 ////////////////////////////////////////////////////////////////////////////////////
 
 void RtcpContextForRecv::onRtp(uint16_t seq, uint32_t stamp, uint64_t ntp_stamp_ms, uint32_t sample_rate, size_t bytes) {

src/Rtcp/RtcpContext.h

@@ -55,6 +55,14 @@ public:
      */
     virtual toolkit::Buffer::Ptr createRtcpSR(uint32_t rtcp_ssrc);
 
+
+    /**
+     * @brief 创建xr的dlrr包，用于接收者估算rtt
+     * 
+     * @return toolkit::Buffer::Ptr 
+     */
+    virtual toolkit::Buffer::Ptr createRtcpXRDLRR(uint32_t rtcp_ssrc, uint32_t rtp_ssrc);
+
     /**
      * 创建RR rtcp包
      * @param rtcp_ssrc rtcp的ssrc
@@ -86,8 +94,11 @@ protected:
 class RtcpContextForSend : public RtcpContext {
 public:
     toolkit::Buffer::Ptr createRtcpSR(uint32_t rtcp_ssrc) override;
+
     void onRtcp(RtcpHeader *rtcp) override;
 
+    toolkit::Buffer::Ptr createRtcpXRDLRR(uint32_t rtcp_ssrc, uint32_t rtp_ssrc) override;
+
     /**
      * 获取rtt
      * @param ssrc rtp ssrc
@@ -98,6 +109,9 @@ public:
 private:
     std::map<uint32_t/*ssrc*/, uint32_t/*rtt*/> _rtt;
     std::map<uint32_t/*last_sr_lsr*/, uint64_t/*ntp stamp*/> _sender_report_ntp;
+
+    std::map<uint32_t/*ssrc*/,uint64_t/*xr rrtr sys stamp*/> _xr_rrtr_recv_sys_stamp;
+    std::map<uint32_t/*ssrc*/,uint32_t/*last rr */> _xr_xrrtr_recv_last_rr;
 };
 
 class RtcpContextForRecv : public RtcpContext {

webrtc/WebRtcTransport.cpp

@@ -774,6 +774,23 @@ void WebRtcTransportImp::onRtcp(const char *buf, size_t len) {
                 }
                 break;
             }
+            case RtcpType::RTCP_XR:{
+                RtcpXRRRTR* xr = (RtcpXRRRTR *) rtcp;
+                if(xr->bt != 4){
+                    break;
+                }
+                auto it = _ssrc_to_track.find(xr->ssrc);
+                if (it == _ssrc_to_track.end()) {
+                     WarnL << "未识别的 rtcp包:" << rtcp->dumpString();
+                     return;
+                }
+                auto &track = it->second;
+                track->rtcp_context_send->onRtcp(rtcp);
+                auto xrdlrr = track->rtcp_context_send->createRtcpXRDLRR(track->answer_ssrc_rtp,track->answer_ssrc_rtp);
+                sendRtcpPacket(xrdlrr->data(), xrdlrr->size(), true);
+
+                break;
+            }
             default: break;
         }
     }