diff --git a/webrtc/RtpExt.cpp b/webrtc/RtpExt.cpp
new file mode 100644
index 00000000..b28306f0
--- /dev/null
+++ b/webrtc/RtpExt.cpp
@@ -0,0 +1,157 @@
+/*
+ * Copyright (c) 2016 The ZLMediaKit project authors. All Rights Reserved.
+ *
+ * This file is part of ZLMediaKit(https://github.com/xia-chu/ZLMediaKit).
+ *
+ * Use of this source code is governed by MIT license that can be found in the
+ * LICENSE file in the root of the source tree. All contributing project authors
+ * may be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "RtpExt.h"
+
+#if defined(_WIN32)
+#pragma pack(push, 1)
+#endif // defined(_WIN32)
+
+//https://tools.ietf.org/html/draft-holmer-rmcat-transport-wide-cc-extensions-01
+//https://tools.ietf.org/html/rfc5285
+
+//       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
+//      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//      |       0xBE    |    0xDE       |           length=3            |
+//      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//      |  ID   | L=0   |     data      |  ID   |  L=1  |   data...
+//      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//            ...data   |    0 (pad)    |    0 (pad)    |  ID   | L=3   |
+//      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//      |                          data                                 |
+//      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+class RtpExtOneByte {
+public:
+    static constexpr uint16_t kMinSize = 1;
+    size_t getSize() const;
+    uint8_t getId() const;
+    uint8_t* getData();
+
+private:
+#if __BYTE_ORDER == __BIG_ENDIAN
+    uint8_t id: 4;
+    uint8_t len: 4;
+#else
+    uint8_t len: 4;
+    uint8_t id: 4;
+#endif
+    uint8_t data[1];
+} 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
+//      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//      |         0x100         |appbits|           length=3            |
+//      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//      |      ID       |     L=0       |     ID        |     L=1       |
+//      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//      |       data    |    0 (pad)    |       ID      |      L=4      |
+//      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//      |                          data                                 |
+//      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+class RtpExtTwoByte {
+public:
+    static constexpr uint16_t kMinSize = 2;
+
+    size_t getSize() const;
+    uint8_t getId() const;
+    uint8_t* getData();
+
+private:
+    uint8_t id;
+    uint8_t len;
+    uint8_t data[1];
+} PACKED;
+
+#if defined(_WIN32)
+#pragma pack(pop)
+#endif // defined(_WIN32)
+
+//////////////////////////////////////////////////////////////////
+
+size_t RtpExtOneByte::getSize() const {
+    return len + 1;
+}
+
+uint8_t RtpExtOneByte::getId() const {
+    return id;
+}
+
+uint8_t *RtpExtOneByte::getData() {
+    return data;
+}
+
+//////////////////////////////////////////////////////////////////
+
+size_t RtpExtTwoByte::getSize() const {
+    return len;
+}
+
+uint8_t RtpExtTwoByte::getId() const {
+    return id;
+}
+
+uint8_t *RtpExtTwoByte::getData() {
+    return data;
+}
+
+//////////////////////////////////////////////////////////////////
+
+static constexpr uint16_t kOneByteHeader = 0xBEDE;
+static constexpr uint16_t kTwoByteHeader = 0x1000;
+
+map<uint8_t/*id*/, string/*data*/> RtpExt::getExtValue(const RtpHeader *header) {
+    map<uint8_t, string> ret;
+    assert(header);
+    auto ext_size = header->getExtSize();
+    if (!ext_size) {
+        return ret;
+    }
+    auto reserved = header->getExtReserved();
+    auto ptr = const_cast<RtpHeader *>(header)->getExtData();
+    auto end = ptr + ext_size;
+
+    if (reserved == kOneByteHeader) {
+        while (ptr < end) {
+            RtpExtOneByte *ext = reinterpret_cast<RtpExtOneByte *>(ptr);
+            if (ext->getId() == 0) {
+                //padding，忽略
+                ++ptr;
+                continue;
+            }
+            //15类型的rtp ext为保留
+            CHECK(ext->getId() != 15);
+            CHECK(reinterpret_cast<uint8_t *>(ext) + RtpExtOneByte::kMinSize <= end);
+            CHECK(ext->getData() + ext->getSize() <= end);
+            ret.emplace(ext->getId(), string(reinterpret_cast<char *>(ext->getData()), ext->getSize()));
+            ptr += RtpExtOneByte::kMinSize + ext->getSize();
+        }
+        return ret;
+    }
+
+    if ((reserved & 0xFFF0) >> 4 == kTwoByteHeader) {
+        while (ptr < end) {
+            RtpExtTwoByte *ext = reinterpret_cast<RtpExtTwoByte *>(ptr);
+            if (ext->getId() == 0) {
+                //padding，忽略
+                ++ptr;
+                continue;
+            }
+            CHECK(reinterpret_cast<uint8_t *>(ext) + RtpExtTwoByte::kMinSize <= end);
+            CHECK(ext->getData() + ext->getSize() <= end);
+            ret.emplace(ext->getId(), string(reinterpret_cast<char *>(ext->getData()), ext->getSize()));
+            ptr += RtpExtTwoByte::kMinSize + ext->getSize();
+        }
+        return ret;
+    }
+
+    return ret;
+}
diff --git a/webrtc/RtpExt.h b/webrtc/RtpExt.h
new file mode 100644
index 00000000..92825e40
--- /dev/null
+++ b/webrtc/RtpExt.h
@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2016 The ZLMediaKit project authors. All Rights Reserved.
+ *
+ * This file is part of ZLMediaKit(https://github.com/xia-chu/ZLMediaKit).
+ *
+ * Use of this source code is governed by MIT license that can be found in the
+ * LICENSE file in the root of the source tree. All contributing project authors
+ * may be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef ZLMEDIAKIT_RTPEXT_H
+#define ZLMEDIAKIT_RTPEXT_H
+
+#include <stdint.h>
+#include <map>
+#include <string>
+#include "Common/macros.h"
+#include "Rtsp/Rtsp.h"
+
+using namespace std;
+using namespace mediakit;
+
+class RtpExt {
+public:
+    static map<uint8_t/*id*/, string/*data*/> getExtValue(const RtpHeader *header);
+};
+
+
+#endif //ZLMEDIAKIT_RTPEXT_H