feat: add support of codec plugin

ext-codec/JPEGRtp.h

@@ -0,0 +1,50 @@
+#ifndef ZLMEDIAKIT_JPEGRTP_H
+#define ZLMEDIAKIT_JPEGRTP_H
+
+#include "Rtsp/RtpCodec.h"
+#include "Extension/Frame.h"
+
+namespace mediakit {
+
+/**
+ * RTP/JPEG specific private data.
+ */
+struct PayloadContext {
+    std::string frame;         ///< current frame buffer
+    uint32_t timestamp;      ///< current frame timestamp
+    int hdr_size;       ///< size of the current frame header
+    uint8_t qtables[128][128];
+    uint8_t qtables_len[128];
+};
+
+/**
+ * 通用 rtp解码类
+ */
+class JPEGRtpDecoder : public RtpCodec {
+public:
+    typedef std::shared_ptr <JPEGRtpDecoder> Ptr;
+
+    JPEGRtpDecoder();
+
+    /**
+     * 输入rtp并解码
+     * @param rtp rtp数据包
+     * @param key_pos 此参数内部强制转换为false,请忽略之
+     */
+    bool inputRtp(const RtpPacket::Ptr &rtp, bool key_pos = false) override;
+
+private:
+    struct PayloadContext _ctx;
+};
+
+class JPEGRtpEncoder : public RtpCodec {
+public:
+    using Ptr = std::shared_ptr<JPEGRtpEncoder>;
+
+    bool inputFrame(const Frame::Ptr &frame) override;
+
+private:
+    void rtpSendJpeg(const uint8_t *buf, int size, uint64_t pts, uint8_t type);
+};
+}//namespace mediakit
+#endif //ZLMEDIAKIT_JPEGRTP_H