diff --git a/article/025-视音频数据处理：UDP-RTP协议解析.md b/article/025-视音频数据处理：UDP-RTP协议解析.md new file mode 100644 index 0000000..9e85e12 --- /dev/null +++ b/article/025-视音频数据处理：UDP-RTP协议解析.md @@ -0,0 +1,252 @@ +# 视音频数据处理：UDP-RTP协议解析 + +本文介绍网络协议数据的处理程序。网络协议数据在视频播放器中的位置如下所示。 + +![image](https://user-images.githubusercontent.com/87458342/127299682-8426891f-6b61-4227-951a-b7b51812cfe1.png) + +本文中的程序是一个UDP/RTP协议流媒体数据解析器。该程序可以分析UDP协议中的RTP 包头中的内容，以及RTP负载中MPEG-TS封装格式的信息。通过修改该程序可以实现不同的UDP/RTP协议数据处理功能。 + +## 原理 + +MPEG-TS封装格式数据打包为RTP/UDP协议然后发送出去的流程如下图所示。图中首先每7个MPEG-TS Packet打包为一个RTP，然后每个RTP再打包为一个UDP。其中打包RTP的方法就是在MPEG-TS数据前面加上RTP Header，而打包RTP的方法就是在RTP数据前面加上UDP Header。 + +![image](https://user-images.githubusercontent.com/87458342/127299752-d161a8b4-1dd7-4050-ae8e-146226dc050a.png) + +有关MPEG-TS、RTP、UDP的知识不再详细介绍，可以参考相关的文档了解其中的细节信息。本文记录的程序是一个收取流媒体的程序，因此本文程序的流程和上述发送MPEG-TS的流程正好是相反的。该程序可以通过Socket编程收取UDP包，解析其中的RTP包的信息，然后再解析RTP包中MPEG-TS Packet的信息。 + +## 代码 + +整个程序位于simplest_udp_parser()函数中，如下所示。 + +```C++ +/** + * 本项目包含如下几种视音频测试示例： + * (1)像素数据处理程序。包含RGB和YUV像素格式处理的函数。 + * (2)音频采样数据处理程序。包含PCM音频采样格式处理的函数。 + * (3)H.264码流分析程序。可以分离并解析NALU。 + * (4)AAC码流分析程序。可以分离并解析ADTS帧。 + * (5)FLV封装格式分析程序。可以将FLV中的MP3音频码流分离出来。 + * (6)UDP-RTP协议分析程序。可以将分析UDP/RTP/MPEG-TS数据包。 + * + * This project contains following samples to handling multimedia data: + * (1) Video pixel data handling program. It contains several examples to handle RGB and YUV data. + * (2) Audio sample data handling program. It contains several examples to handle PCM data. + * (3) H.264 stream analysis program. It can parse H.264 bitstream and analysis NALU of stream. + * (4) AAC stream analysis program. It can parse AAC bitstream and analysis ADTS frame of stream. + * (5) FLV format analysis program. It can analysis FLV file and extract MP3 audio stream. + * (6) UDP-RTP protocol analysis program. It can analysis UDP/RTP/MPEG-TS Packet. + * + */ +#include +#include + +#pragma comment(lib, "ws2_32.lib") + +#pragma pack(1) + +/* + * [memo] FFmpeg stream Command: + * ffmpeg -re -i sintel.ts -f mpegts udp://127.0.0.1:8880 + * ffmpeg -re -i sintel.ts -f rtp_mpegts udp://127.0.0.1:8880 + */ + +typedef struct RTP_FIXED_HEADER{ + /* byte 0 */ + unsigned char csrc_len:4; /* expect 0 */ + unsigned char extension:1; /* expect 1 */ + unsigned char padding:1; /* expect 0 */ + unsigned char version:2; /* expect 2 */ + /* byte 1 */ + unsigned char payload:7; + unsigned char marker:1; /* expect 1 */ + /* bytes 2, 3 */ + unsigned short seq_no; + /* bytes 4-7 */ + unsigned long timestamp; + /* bytes 8-11 */ + unsigned long ssrc; /* stream number is used here. */ +} RTP_FIXED_HEADER; + +typedef struct MPEGTS_FIXED_HEADER { + unsigned sync_byte: 8; + unsigned transport_error_indicator: 1; + unsigned payload_unit_start_indicator: 1; + unsigned transport_priority: 1; + unsigned PID: 13; + unsigned scrambling_control: 2; + unsigned adaptation_field_exist: 2; + unsigned continuity_counter: 4; +} MPEGTS_FIXED_HEADER; + + + +int simplest_udp_parser(int port) +{ + WSADATA wsaData; + WORD sockVersion = MAKEWORD(2,2); + int cnt=0; + + //FILE *myout=fopen("output_log.txt","wb+"); + FILE *myout=stdout; + + FILE *fp1=fopen("output_dump.ts","wb+"); + + if(WSAStartup(sockVersion, &wsaData) != 0){ + return 0; + } + + SOCKET serSocket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP); + if(serSocket == INVALID_SOCKET){ + printf("socket error !"); + return 0; + } + + sockaddr_in serAddr; + serAddr.sin_family = AF_INET; + serAddr.sin_port = htons(port); + serAddr.sin_addr.S_un.S_addr = INADDR_ANY; + if(bind(serSocket, (sockaddr *)&serAddr, sizeof(serAddr)) == SOCKET_ERROR){ + printf("bind error !"); + closesocket(serSocket); + return 0; + } + + sockaddr_in remoteAddr; + int nAddrLen = sizeof(remoteAddr); + + //How to parse? + int parse_rtp=1; + int parse_mpegts=1; + + printf("Listening on port %d\n",port); + + char recvData[10000]; + while (1){ + + int pktsize = recvfrom(serSocket, recvData, 10000, 0, (sockaddr *)&remoteAddr, &nAddrLen); + if (pktsize > 0){ + //printf("Addr:%s\r\n",inet_ntoa(remoteAddr.sin_addr)); + //printf("packet size:%d\r\n",pktsize); + //Parse RTP + // + if(parse_rtp!=0){ + char payload_str[10]={0}; + RTP_FIXED_HEADER rtp_header; + int rtp_header_size=sizeof(RTP_FIXED_HEADER); + //RTP Header + memcpy((void *)&rtp_header,recvData,rtp_header_size); + + //RFC3551 + char payload=rtp_header.payload; + switch(payload){ + case 0: + case 1: + case 2: + case 3: + case 4: + case 5: + case 6: + case 7: + case 8: + case 9: + case 10: + case 11: + case 12: + case 13: + case 14: + case 15: + case 16: + case 17: + case 18: sprintf(payload_str,"Audio");break; + case 31: sprintf(payload_str,"H.261");break; + case 32: sprintf(payload_str,"MPV");break; + case 33: sprintf(payload_str,"MP2T");break; + case 34: sprintf(payload_str,"H.263");break; + case 96: sprintf(payload_str,"H.264");break; + default:sprintf(payload_str,"other");break; + } + + unsigned int timestamp=ntohl(rtp_header.timestamp); + unsigned int seq_no=ntohs(rtp_header.seq_no); + + fprintf(myout,"[RTP Pkt] %5d| %5s| %10u| %5d| %5d|\n",cnt,payload_str,timestamp,seq_no,pktsize); + + //RTP Data + char *rtp_data=recvData+rtp_header_size; + int rtp_data_size=pktsize-rtp_header_size; + fwrite(rtp_data,rtp_data_size,1,fp1); + + //Parse MPEGTS + if(parse_mpegts!=0&&payload==33){ + MPEGTS_FIXED_HEADER mpegts_header; + for(int i=0;i +
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+ +原文作者： 雷霄骅 diff --git a/article/025.README.md b/article/025.README.md deleted file mode 100644 index 792d600..0000000 --- a/article/025.README.md +++ /dev/null @@ -1 +0,0 @@ -#