From a1b2aa9abb3cdf9445e82f58e9b9b406d46c509d Mon Sep 17 00:00:00 2001
From: xiongziliang <771730766@qq.com>
Date: Mon, 29 Mar 2021 23:55:29 +0800
Subject: [PATCH] =?UTF-8?q?=E6=95=B4=E7=90=86=E4=B8=8E=E6=A0=A1=E9=AA=8C?=
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---
 webrtc/Sdp.cpp | 53 ++++++++++++++++++++++++++++++++++++++++++++++++--
 webrtc/Sdp.h   | 43 +++++++++++++++++++++++-----------------
 2 files changed, 76 insertions(+), 20 deletions(-)

diff --git a/webrtc/Sdp.cpp b/webrtc/Sdp.cpp
index 0cfa1892..10074f7d 100644
--- a/webrtc/Sdp.cpp
+++ b/webrtc/Sdp.cpp
@@ -949,9 +949,7 @@ void RtcSession::loadFrom(const string &str) {
             if (group.isFID()) {
                 ssrc_rtp = group.u.fid.rtp_ssrc;
                 ssrc_rtx = group.u.fid.rtx_ssrc;
-                rtc_media.rtx = true;
             } else if (group.isSIM()) {
-                rtc_media.simulcast = true;
                 ssrc_rtp_low = group.u.sim.rtp_ssrc_low;
                 ssrc_rtp_mid = group.u.sim.rtp_ssrc_mid;
                 ssrc_rtp_high = group.u.sim.rtp_ssrc_high;
@@ -1033,4 +1031,55 @@ void RtcSession::loadFrom(const string &str) {
     }
 
     group = sdp.getItemClass<SdpAttrGroup>('a', "group");
+    checkValid();
 }
+
+string RtcCodecPlan::getFmtp(const char *key) const{
+    for (auto &item : fmtp) {
+        if (item.first == key) {
+            return item.second;
+        }
+    }
+    return "";
+}
+
+const RtcCodecPlan *RtcMedia::getPlan(uint8_t pt) const{
+    for (auto &item : plan) {
+        if (item.pt == pt) {
+            return &item;
+        }
+    }
+    return nullptr;
+}
+
+void RtcMedia::checkValid() const{
+    switch (direction) {
+        case RtpDirection::sendonly:
+        case RtpDirection::sendrecv: {
+            if (rtp_ssrc.empty()) {
+                throw std::invalid_argument("发送rtp但是未指定rtp ssrc");
+            }
+            break;
+        }
+        default: break;
+    }
+    for (auto &item : plan) {
+        if (item.codec == "rtx") {
+            if (rtx_ssrc.empty()) {
+                throw std::invalid_argument("指定开启rtx但是未指定rtx ssrc");
+            }
+            auto apt = atoi(item.getFmtp("apt").data());
+            if (!getPlan(apt)) {
+                throw std::invalid_argument("找不到rtx关联的plan信息");
+            }
+        }
+    }
+    //todo 校验更多信息
+}
+
+void RtcSession::checkValid() const{
+    for (auto &item : media) {
+        item.checkValid();
+    }
+    //todo 校验更多信息
+}
\ No newline at end of file
diff --git a/webrtc/Sdp.h b/webrtc/Sdp.h
index ed2ddad5..60f8c6b8 100644
--- a/webrtc/Sdp.h
+++ b/webrtc/Sdp.h
@@ -517,6 +517,8 @@ public:
     string msid;
     string mslabel;
     string label;
+
+    bool empty() const {return ssrc == 0;}
 };
 
 //rtc传输编码方案
@@ -527,47 +529,48 @@ public:
     uint32_t sample_rate;
     //音频时有效
     uint32_t channel = 0;
+    //rtcp反馈
     vector<string> rtcp_fb;
     vector<std::pair<string/*key*/, string/*value*/> > fmtp;
+
+    string getFmtp(const char *key) const;
 };
 
 //rtc 媒体描述
 class RtcMedia{
 public:
-    TrackType type;
+    TrackType type{TrackType::TrackInvalid};
     string mid;
-    uint16_t port;
+    uint16_t port{0};
+    SdpConnection addr;
     string proto;
+    RtpDirection direction{RtpDirection::invalid};
+    vector<RtcCodecPlan> plan;
 
     //////// rtp ////////
     RtcSSRC rtp_ssrc;
-    // for simulcast
-    bool simulcast{false};
+    RtcSSRC rtx_ssrc;
+
+    //////// simulcast ////////
     RtcSSRC rtp_ssrc_low;
     RtcSSRC rtp_ssrc_mid;
     RtcSSRC rtp_ssrc_high;
 
-    SdpConnection addr;
-    RtpDirection direction;
-    vector<RtcCodecPlan> plan;
-
-    //////// rtx - rtcp  ////////
-    bool rtx{false};
-    bool rtcp_mux;
-    bool rtcp_rsize;
-    RtcSSRC rtx_ssrc;
+    ////////  rtcp  ////////
+    bool rtcp_mux{false};
+    bool rtcp_rsize{false};
     SdpAttrRtcp rtcp_addr;
 
     //////// ice ////////
-    bool ice_trickle;
-    bool ice_lite;
-    bool ice_renomination;
+    bool ice_trickle{false};
+    bool ice_lite{false};
+    bool ice_renomination{false};
     string ice_ufrag;
     string ice_pwd;
     std::vector<SdpAttrCandidate> candidate;
 
     //////// dtls ////////
-    DtlsRole role;
+    DtlsRole role{DtlsRole::invalid};
     SdpAttrFingerprint fingerprint;
 
     //////// extmap ////////
@@ -575,7 +578,10 @@ public:
 
     //////// sctp ////////////
     SdpAttrSctpMap sctpmap;
-    uint32_t sctp_port {0};
+    uint32_t sctp_port{0};
+
+    void checkValid() const;
+    const RtcCodecPlan *getPlan(uint8_t pt) const;
 };
 
 class RtcSession{
@@ -591,6 +597,7 @@ public:
     SdpAttrGroup group;
 
     void loadFrom(const string &sdp);
+    void checkValid() const;
 };