linux下基于libRTMP的接收流媒体的程序

看了雷博的一篇关于rtmp的文章，学习记录以作备忘。

使用librtmp接收RTMP流的函数执行流程图如下图：

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_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。
RTMP_Read()：从服务器读取数据。
RTMP_Close()：关闭RTMP连接。
RTMP_Free()：释放结构体“RTMP”。
CleanupSockets()：关闭Socket。

其中NetStream和NetConnection是RTMP协议规范中的两个逻辑结构。NetStream建立在NetConnection之上。一个NetConnection可以包含多个NetStream。它们之间的关系如下图所示：

源代码rtmp2flv.c：

#include <stdio.h>#include <stdlib.h>#include "librtmp/rtmp_sys.h"#include "librtmp/log.h"#include "librtmp/rtmp.h"int InitSockets(){#if 0WORD version;WSADATA wsaData;version = MAKEWORD(1, 1);return (WSAStartup(version, &wsaData) == 0);#endif}void CleanupSockets(){#if 0WSACleanup();#endif}int main(int argc, char* argv[]){InitSockets();double duration=-1;int nRead;//is live stream ?char bLiveStream=1;int bufsize=1024*1024*10;char *buf=(char*)malloc(bufsize);memset(buf,0,bufsize);long countbufsize=0;FILE *fp=fopen("receive.flv","wb");if (!fp){RTMP_LogPrintf("Open File Error.\n");CleanupSockets();return -1;}/* set log level *///RTMP_LogLevel loglvl=RTMP_LOGDEBUG;//RTMP_LogSetLevel(loglvl);RTMP *rtmp=RTMP_Alloc();RTMP_Init(rtmp);//set connection timeout,default 30srtmp->Link.timeout=10;// HKS's live URLif(!RTMP_SetupURL(rtmp,"rtmp://live.hkstv.hk.lxdns.com/live/hks")){RTMP_Log(RTMP_LOGERROR,"SetupURL Err\n");RTMP_Free(rtmp);CleanupSockets();return -1;}if (bLiveStream){rtmp->Link.lFlags|=RTMP_LF_LIVE;}//1hourRTMP_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;}while(nRead=RTMP_Read(rtmp,buf,bufsize)){fwrite(buf,1,nRead,fp);countbufsize+=nRead;RTMP_LogPrintf("Receive: %5dByte, Total: %5.2fkB\n",nRead,countbufsize*1.0/1024);}if(fp)fclose(fp);if(buf){free(buf);}if(rtmp){RTMP_Close(rtmp);RTMP_Free(rtmp);CleanupSockets();rtmp=NULL;}return 0;}

这里面包含rtmp的几个头文件，需要借助librtmp的库，可以随意在网上下个，我找了雷神的那个：

http://download.csdn.net/download/leixiaohua1020/8291757

我只拷贝了librtmp，和顶层的Makefile，Makefile做了一点点修改来编译rtmp2flv.c

Makefile：

VERSION=v2.3prefix=/usr/localCC=$(CROSS_COMPILE)gccLD=$(CROSS_COMPILE)ldSYS=posix#SYS=mingwCRYPTO=OPENSSL#CRYPTO=POLARSSL#CRYPTO=GNUTLSLIB_GNUTLS=-lgnutls -lgcryptLIB_OPENSSL=-lssl -lcryptoLIB_POLARSSL=-lpolarsslCRYPTO_LIB=$(LIB_$(CRYPTO))DEF_=-DNO_CRYPTOCRYPTO_DEF=$(DEF_$(CRYPTO))DEF=-DRTMPDUMP_VERSION=\"$(VERSION)\" $(CRYPTO_DEF) $(XDEF)OPT=-O2CFLAGS=-Wall $(XCFLAGS) $(INC) $(DEF) $(OPT)LDFLAGS=-Wall $(XLDFLAGS)bindir=$(prefix)/binsbindir=$(prefix)/sbinmandir=$(prefix)/manBINDIR=$(DESTDIR)$(bindir)SBINDIR=$(DESTDIR)$(sbindir)MANDIR=$(DESTDIR)$(mandir)LIBS_posix=LIBS_mingw=-lws2_32 -lwinmm -lgdi32LIBS=$(CRYPTO_LIB) -lz $(LIBS_$(SYS)) $(XLIBS)THREADLIB_posix=-lpthreadTHREADLIB_mingw=THREADLIB=$(THREADLIB_$(SYS))SLIBS=$(THREADLIB) $(LIBS)LIBRTMP=librtmp/librtmp.aINCRTMP=librtmp/rtmp_sys.h librtmp/rtmp.h librtmp/log.h librtmp/amf.hEXT_posix=EXT_mingw=.exeEXT=$(EXT_$(SYS))all:$(LIBRTMP) progsprogs:rtmp2flv rtmpdump rtmpgw rtmpsrv rtmpsuckinstall:progs-mkdir -p $(BINDIR) $(SBINDIR) $(MANDIR)/man1 $(MANDIR)/man8cp rtmpdump$(EXT) $(BINDIR)cp rtmpgw$(EXT) rtmpsrv$(EXT) rtmpsuck$(EXT) $(SBINDIR)cp rtmpdump.1 $(MANDIR)/man1cp rtmpgw.8 $(MANDIR)/man8@cd librtmp; $(MAKE) installclean:rm -f *.o rtmp2flv$(EXT) rtmpdump$(EXT) rtmpgw$(EXT) rtmpsrv$(EXT) rtmpsuck$(EXT)@cd librtmp; $(MAKE) cleanFORCE:$(LIBRTMP): FORCE@cd librtmp; $(MAKE) all# note: $^ is GNU Make's equivalent to BSD $># we use both since either make will ignore the one it doesn't recognizertmp2flv: rtmp2flv.o $(LIBRTMP)$(CC) $(LDFLAGS) $^ $> -o $@$(EXT) $(LIBS)rtmpdump: rtmpdump.o $(LIBRTMP)$(CC) $(LDFLAGS) $^ $> -o $@$(EXT) $(LIBS)rtmpsrv: rtmpsrv.o thread.o $(LIBRTMP)$(CC) $(LDFLAGS) $^ $> -o $@$(EXT) $(SLIBS)rtmpsuck: rtmpsuck.o thread.o $(LIBRTMP)$(CC) $(LDFLAGS) $^ $> -o $@$(EXT) $(SLIBS)rtmpgw: rtmpgw.o thread.o $(LIBRTMP)$(CC) $(LDFLAGS) $^ $> -o $@$(EXT) $(SLIBS)rtmp2flv.o: rtmp2flv.c $(INCRTMP) Makefilertmpgw.o: rtmpgw.c $(INCRTMP) Makefilertmpdump.o: rtmpdump.c $(INCRTMP) Makefilertmpsrv.o: rtmpsrv.c $(INCRTMP) Makefilertmpsuck.o: rtmpsuck.c $(INCRTMP) Makefilethread.o: thread.c thread.h

./rtmp2flv运行程序

用smplayer receive.flv 来播放视频:

感谢雷神！