JT/T1078-RTP音视频封包

《音视频应用开发系列文章目录》

JT1078-RTP包结构

JT1078-RTP音视频包定义

#pragma pack(push)
#pragma pack (1)
typedef struct Jt1078AudioRtpPacket_T {

    unsigned char head[4];
#if IS_JT1078RTP_BIGENDIAN // 大小端模式
    unsigned char v : 2;
    unsigned char p : 1;
    unsigned char x : 1;
    unsigned char cc : 4;
    unsigned char m : 1;
    unsigned char pt : 7;
#else
    unsigned char cc : 4;
    unsigned char x : 1;
    unsigned char p : 1;
    unsigned char v : 2;
    unsigned char pt : 7;
    unsigned char m : 1;
#endif
    unsigned short seq;
    unsigned char sim[6];
    unsigned char ch;
#if IS_JT1078RTP_BIGENDIAN
    unsigned char frame_type : 4;
    unsigned char packet_type : 4;
#else
    unsigned char packet_type : 4;
    unsigned char frame_type : 4;
#endif
    int64_t timestamp;
    unsigned short payload_size;

}Jt1078AudioRtpPacket;

JT1078-RTP视频包定义

#pragma pack(push)
#pragma pack (1)
typedef struct Jt1078VideoRtpPacket_T {

    unsigned char head[4];
#if IS_JT1078RTP_BIGENDIAN
    unsigned char v : 2;
    unsigned char p : 1;
    unsigned char x : 1;
    unsigned char cc : 4;
    unsigned char m : 1;
    unsigned char pt : 7;
#else
    unsigned char cc : 4;
    unsigned char x : 1;
    unsigned char p : 1;
    unsigned char v : 2;
    unsigned char pt : 7;
    unsigned char m : 1;
#endif
    unsigned short seq;
    unsigned char sim[6];
    unsigned char ch;
#if IS_JT1078RTP_BIGENDIAN
    unsigned char frame_type : 4;
    unsigned char packet_type : 4;
#else
    unsigned char packet_type : 4;
    unsigned char frame_type : 4;
#endif
    int64_t timestamp;
    unsigned short i_frame_interval;
    unsigned short frame_interval;
    unsigned short payload_size;

}Jt1078VideoRtpPacket;
#pragma pack(pop)

JT1078-RTP音频包封装

填充结构体Jt1078AudioRtpPacket即可，需要注意的是sim是BCD码，大小端根据实际情况转换。payload_size，最大是950byte。音频帧无需分包，每包能发950就发950。

JT1078-RTP视频包封装

填充结构体Jt1078VideoRtpPacket即可，需要注意的是sim是BCD码，大小端根据实际情况转换。如果视频帧大于950byte，需要分包发送。比如某帧视频的大小是2000byte，则先发950且packet_type为第一包，再发950且packet_type为中间包，最后发100且packet_type为最后一个包，可以在一个循环内完成。***以RTP包递增，不管是音频还是视频，共用同一个seq。