最简单的基于librtmp的示例：发布（FLV通过RTMP发布）

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最简单的基于libRTMP的示例系列文章列表：

最简单的基于librtmp的示例：接收（RTMP保存为FLV）

最简单的基于librtmp的示例：发布（FLV通过RTMP发布）

最简单的基于librtmp的示例：发布H.264（H.264通过RTMP发布）

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本文记录一个基于libRTMP的发布流媒体的程序：Simplest libRTMP Send FLV。该程序可以将本地FLV文件发布到RTMP流媒体服务器。是最简单的基于libRTMP的流媒体发布示例。

 

流程图

使用librtmp发布RTMP流的可以使用两种API：RTMP_SendPacket()和RTMP_Write()。使用RTMP_SendPacket()发布流的时候的函数执行流程图如下图所示。使用RTMP_Write()发布流的时候的函数执行流程图相差不大。

流程图中关键函数的作用如下所列：

InitSockets()：初始化Socket
RTMP_Alloc()：为结构体“RTMP”分配内存。
RTMP_Init()：初始化结构体“RTMP”中的成员变量。
RTMP_SetupURL()：设置输入的RTMP连接的URL。
RTMP_EnableWrite()：发布流的时候必须要使用。如果不使用则代表接收流。
RTMP_Connect()：建立RTMP连接，创建一个RTMP协议规范中的NetConnection。
RTMP_ConnectStream()：创建一个RTMP协议规范中的NetStream。
Delay：发布流过程中的延时，保证按正常播放速度发送数据。
RTMP_SendPacket()：发送一个RTMP数据RTMPPacket。
RTMP_Close()：关闭RTMP连接。
RTMP_Free()：释放结构体“RTMP”。
CleanupSockets()：关闭Socket。
 

源代码

源代码中包含了使用两种API函数RTMP_SendPacket()和RTMP_Write()发布流媒体的源代码，如下所示。

/**
 * Simplest Librtmp Send FLV
 *
 * 雷霄骅，张晖
 * leixiaohua1020@126.com
 * zhanghuicuc@gmail.com
 * 中国传媒大学/数字电视技术
 * Communication University of China / Digital TV Technology
 * http://blog.csdn.net/leixiaohua1020
 *
 * 本程序用于将FLV格式的视音频文件使用RTMP推送至RTMP流媒体服务器。
 * This program can send local flv file to net server as a rtmp live stream.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#ifndef WIN32
#include <unistd.h>
#endif

#include "librtmp/rtmp_sys.h"
#include "librtmp/log.h"

#define HTON16(x)  ((x>>8&0xff)|(x<<8&0xff00))
#define HTON24(x)  ((x>>16&0xff)|(x<<16&0xff0000)|(x&0xff00))
#define HTON32(x)  ((x>>24&0xff)|(x>>8&0xff00)|\
         (x<<8&0xff0000)|(x<<24&0xff000000))
#define HTONTIME(x) ((x>>16&0xff)|(x<<16&0xff0000)|(x&0xff00)|(x&0xff000000))

/*read 1 byte*/
int ReadU8(uint32_t *u8,FILE*fp){
         if(fread(u8,1,1,fp)!=1)
                   return 0;
         return 1;
}
/*read 2 byte*/
int ReadU16(uint32_t *u16,FILE*fp){
         if(fread(u16,2,1,fp)!=1)
                   return 0;
         *u16=HTON16(*u16);
         return 1;
}
/*read 3 byte*/
int ReadU24(uint32_t *u24,FILE*fp){
         if(fread(u24,3,1,fp)!=1)
                   return 0;
         *u24=HTON24(*u24);
         return 1;
}
/*read 4 byte*/
int ReadU32(uint32_t *u32,FILE*fp){
         if(fread(u32,4,1,fp)!=1)
                   return 0;
         *u32=HTON32(*u32);
         return 1;
}
/*read 1 byte,and loopback 1 byte at once*/
int PeekU8(uint32_t *u8,FILE*fp){
         if(fread(u8,1,1,fp)!=1)
                   return 0;
         fseek(fp,-1,SEEK_CUR);
         return 1;
}
/*read 4 byte and convert to time format*/
int ReadTime(uint32_t *utime,FILE*fp){
         if(fread(utime,4,1,fp)!=1)
                   return 0;
         *utime=HTONTIME(*utime);
         return 1;
}

int InitSockets()
{
         WORD version;
         WSADATA wsaData;
         version=MAKEWORD(2,2);
         return (WSAStartup(version, &wsaData) == 0);
}

void CleanupSockets()
{
         WSACleanup();
}

//Publish using RTMP_SendPacket()
int publish_using_packet(){
         RTMP *rtmp=NULL;
         RTMPPacket *packet=NULL;
         uint32_t start_time=0;
         uint32_t now_time=0;
         //the timestamp of the previous frame
         long pre_frame_time=0;
         long lasttime=0;
         int bNextIsKey=1;
         uint32_t preTagsize=0;

         //packet attributes
         uint32_t type=0;
         uint32_t datalength=0;
         uint32_t timestamp=0;
         uint32_t streamid=0;                        

         FILE*fp=NULL;
         fp=fopen("cuc_ieschool.flv","rb");
         if (!fp){
                   RTMP_LogPrintf("Open File Error.\n");
                   CleanupSockets();
                   return -1;
         }

         /* set log level */
         //RTMP_LogLevel loglvl=RTMP_LOGDEBUG;
         //RTMP_LogSetLevel(loglvl);

         if (!InitSockets()){
                   RTMP_LogPrintf("Init Socket Err\n");
                   return -1;
         }

         rtmp=RTMP_Alloc();
         RTMP_Init(rtmp);
         //set connection timeout,default 30s
         rtmp->Link.timeout=5;
         if(!RTMP_SetupURL(rtmp,"rtmp://localhost/publishlive/livestream"))
         {
                   RTMP_Log(RTMP_LOGERROR,"SetupURL Err\n");
                   RTMP_Free(rtmp);
                   CleanupSockets();
                   return -1;
         }

         //if unable,the AMF command would be 'play' instead of 'publish'
         RTMP_EnableWrite(rtmp);     

         if (!RTMP_Connect(rtmp,NULL)){
                   RTMP_Log(RTMP_LOGERROR,"Connect Err\n");
                   RTMP_Free(rtmp);
                   CleanupSockets();
                   return -1;
         }

         if (!RTMP_ConnectStream(rtmp,0)){
                   RTMP_Log(RTMP_LOGERROR,"ConnectStream Err\n");
                   RTMP_Close(rtmp);
                   RTMP_Free(rtmp);
                   CleanupSockets();
                   return -1;
         }

         packet=(RTMPPacket*)malloc(sizeof(RTMPPacket));
         RTMPPacket_Alloc(packet,1024*64);
         RTMPPacket_Reset(packet);

         packet->m_hasAbsTimestamp = 0;
         packet->m_nChannel = 0x04;
         packet->m_nInfoField2 = rtmp->m_stream_id;

         RTMP_LogPrintf("Start to send data ...\n");

         //jump over FLV Header
         fseek(fp,9,SEEK_SET);
         //jump over previousTagSizen
         fseek(fp,4,SEEK_CUR);
         start_time=RTMP_GetTime();
         while(1)
         {
                   if((((now_time=RTMP_GetTime())-start_time)
                              <(pre_frame_time)) && bNextIsKey){
                            //wait for 1 sec if the send process is too fast
                            //this mechanism is not very good,need some improvement
                            if(pre_frame_time>lasttime){
                                     RTMP_LogPrintf("TimeStamp:%8lu ms\n",pre_frame_time);
                                     lasttime=pre_frame_time;
                            }
                            Sleep(1000);
                            continue;
                   }

                   //not quite the same as FLV spec
                   if(!ReadU8(&type,fp))
                            break;
                   if(!ReadU24(&datalength,fp))
                            break;
                   if(!ReadTime(×tamp,fp))
                            break;
                   if(!ReadU24(&streamid,fp))
                            break;

                   if (type!=0x08&&type!=0x09){
                            //jump over non_audio and non_video frame，
                            //jump over next previousTagSizen at the same time
                            fseek(fp,datalength+4,SEEK_CUR);
                            continue;
                   }

                   if(fread(packet->m_body,1,datalength,fp)!=datalength)
                            break;

                   packet->m_headerType = RTMP_PACKET_SIZE_LARGE;
                   packet->m_nTimeStamp = timestamp;
                   packet->m_packetType = type;
                   packet->m_nBodySize  = datalength;
                   pre_frame_time=timestamp;

                   if (!RTMP_IsConnected(rtmp)){
                            RTMP_Log(RTMP_LOGERROR,"rtmp is not connect\n");
                            break;
                   }
                   if (!RTMP_SendPacket(rtmp,packet,0)){
                            RTMP_Log(RTMP_LOGERROR,"Send Error\n");
                            break;
                   }

                   if(!ReadU32(&preTagsize,fp))
                            break;

                   if(!PeekU8(&type,fp))
                            break;
                   if(type==0x09){
                            if(fseek(fp,11,SEEK_CUR)!=0)
                                     break;
                            if(!PeekU8(&type,fp)){
                                     break;
                            }
                            if(type==0x17)
                                     bNextIsKey=1;
                            else
                                     bNextIsKey=0;

                            fseek(fp,-11,SEEK_CUR);
                   }
         }               

         RTMP_LogPrintf("\nSend Data Over\n");

         if(fp)
                   fclose(fp);

         if (rtmp!=NULL){
                   RTMP_Close(rtmp);
                   RTMP_Free(rtmp);
                   rtmp=NULL;
         }
         if (packet!=NULL){
                   RTMPPacket_Free(packet);
                   free(packet);
                   packet=NULL;
         }

         CleanupSockets();
         return 0;
}

//Publish using RTMP_Write()
int publish_using_write(){
         uint32_t start_time=0;
         uint32_t now_time=0;
         uint32_t pre_frame_time=0;
         uint32_t lasttime=0;
         int bNextIsKey=0;
         char* pFileBuf=NULL;

         //read from tag header
         uint32_t type=0;
         uint32_t datalength=0;
         uint32_t timestamp=0;

         RTMP *rtmp=NULL;                           

         FILE*fp=NULL;
         fp=fopen("cuc_ieschool.flv","rb");
         if (!fp){
                   RTMP_LogPrintf("Open File Error.\n");
                   CleanupSockets();
                   return -1;
         }

         /* set log level */
         //RTMP_LogLevel loglvl=RTMP_LOGDEBUG;
         //RTMP_LogSetLevel(loglvl);

         if (!InitSockets()){
                  RTMP_LogPrintf("Init Socket Err\n");
                   return -1;
         }

         rtmp=RTMP_Alloc();
         RTMP_Init(rtmp);
         //set connection timeout,default 30s
         rtmp->Link.timeout=5;
         if(!RTMP_SetupURL(rtmp,"rtmp://localhost/publishlive/livestream"))
         {
                   RTMP_Log(RTMP_LOGERROR,"SetupURL Err\n");
                   RTMP_Free(rtmp);
                   CleanupSockets();
                   return -1;
         }

         RTMP_EnableWrite(rtmp);
         //1hour
         RTMP_SetBufferMS(rtmp, 3600*1000);
         if (!RTMP_Connect(rtmp,NULL)){
                   RTMP_Log(RTMP_LOGERROR,"Connect Err\n");
                   RTMP_Free(rtmp);
                   CleanupSockets();
                   return -1;
         }

         if (!RTMP_ConnectStream(rtmp,0)){
                   RTMP_Log(RTMP_LOGERROR,"ConnectStream Err\n");
                   RTMP_Close(rtmp);
                   RTMP_Free(rtmp);
                   CleanupSockets();
                   return -1;
         }

         printf("Start to send data ...\n");

         //jump over FLV Header
         fseek(fp,9,SEEK_SET);
         //jump over previousTagSizen
         fseek(fp,4,SEEK_CUR);
         start_time=RTMP_GetTime();
         while(1)
         {
                   if((((now_time=RTMP_GetTime())-start_time)
                              <(pre_frame_time)) && bNextIsKey){
                            //wait for 1 sec if the send process is too fast
                            //this mechanism is not very good,need some improvement
                            if(pre_frame_time>lasttime){
                                     RTMP_LogPrintf("TimeStamp:%8lu ms\n",pre_frame_time);
                                     lasttime=pre_frame_time;
                            }
                            Sleep(1000);
                            continue;
                   }

                   //jump over type
                   fseek(fp,1,SEEK_CUR);
                   if(!ReadU24(&datalength,fp))
                            break;
                   if(!ReadTime(×tamp,fp))
                            break;
                   //jump back
                   fseek(fp,-8,SEEK_CUR);  

                   pFileBuf=(char*)malloc(11+datalength+4);
                   memset(pFileBuf,0,11+datalength+4);
                   if(fread(pFileBuf,1,11+datalength+4,fp)!=(11+datalength+4))
                            break;

                   pre_frame_time=timestamp;

                   if (!RTMP_IsConnected(rtmp)){
                            RTMP_Log(RTMP_LOGERROR,"rtmp is not connect\n");
                            break;
                   }
                   if (!RTMP_Write(rtmp,pFileBuf,11+datalength+4)){
                            RTMP_Log(RTMP_LOGERROR,"Rtmp Write Error\n");
                            break;
                   }

                   free(pFileBuf);
                   pFileBuf=NULL;

                   if(!PeekU8(&type,fp))
                            break;
                   if(type==0x09){
                            if(fseek(fp,11,SEEK_CUR)!=0)
                                     break;
                            if(!PeekU8(&type,fp)){
                                     break;
                            }
                            if(type==0x17)
                                     bNextIsKey=1;
                            else
                                     bNextIsKey=0;
                            fseek(fp,-11,SEEK_CUR);
                   }
         }

         RTMP_LogPrintf("\nSend Data Over\n");

         if(fp)
                   fclose(fp);

         if (rtmp!=NULL){
                   RTMP_Close(rtmp);
                   RTMP_Free(rtmp);
                   rtmp=NULL;
         }

         if(pFileBuf){
                   free(pFileBuf);
                   pFileBuf=NULL;
         }

         CleanupSockets();
         return 0;
}

int main(int argc, char* argv[]){
         //2 Methods:
         publish_using_packet();
         //publish_using_write();
         return 0;
}

运行结果

程序运行后，会将“cuc_ieschool.flv”文件以直播流的形式发布到“rtmp://localhost/publishlive/livestream”的URL。修改文件名称和RTMP的URL可以实现将任意flv文件发布到任意RTMP的URL。

下载

Simplest LibRTMP Example
 

项目主页

SourceForge：https://sourceforge.net/projects/simplestlibrtmpexample/

Github：https://github.com/leixiaohua1020/simplest_librtmp_example

开源中国：http://git.oschina.net/leixiaohua1020/simplest_librtmp_example

CSDN下载：http://download.csdn.net/detail/leixiaohua1020/8291757
 
本工程包含了LibRTMP的使用示例，包含如下子工程：
simplest_librtmp_receive: 接收RTMP流媒体并在本地保存成FLV格式的文件。
simplest_librtmp_send_flv: 将FLV格式的视音频文件使用RTMP推送至RTMP流媒体服务器。
simplest_librtmp_send264: 将内存中的H.264数据推送至RTMP流媒体服务器。