文如其名，最近在做的項目要求利用RTSP協議轉發處理完的H264視頻數據給上一層客戶端，環境是Windows的VS2013，于是就各種百度谷歌找代碼。結果在得到利用live555去做比較簡單的結論的同時也悲情地發現，網上別人貼出來的代碼基本都是Linux上面的。在修改了兩份來適用于Windows無效后，又一次陷入了百度谷歌的無盡搜索中。Anyway，最后終于解決了，所以貼出代碼跟大家分享下，希望能給和我需求相似的童鞋一點啟發，也希望有高手指正其中的問題。
用live555進行RTSP的播放基本上是通過修改其給出來的播放本地文件的DEMO來實現的。但由于其DEMO封裝的比較深，所以要直接修改他的fread處的代碼變成內存拷貝來實現實時傳輸會顯得比較別扭。本文參考了網上的一些代碼，自定義了一個繼承自H264VideoFileServerMediaSubsession的類來來進行處理，同時定義了一個繼承自FramedSource的類來做內存的拷貝操作，該類亦是區別于讀本地文件和實時流之緊要處。
代碼如下，如果覺得需要或者懶得自己搭建live555的環境亦可以在文中最后的鏈接中下載該工程（環境為VS2013），如果你的VS版本合適即可直接運行。
主文件（程序入口）
#include "H264LiveVideoServerMediaSubssion.hh"
#include "H264FramedLiveSource.hh"
#include "liveMedia.hh"
#include "BasicUsageEnvironment.hh"
#define BUFSIZE 1024*200
static void announceStream(RTSPServer* rtspServer, ServerMediaSession* sms,char const* streamName)//顯示RTSP連接信息
{
char* url = rtspServer->rtspURL(sms);
UsageEnvironment env = rtspServer->envir();
env streamName "\n";
env "Play this stream using the URL \&;" url "\&;\n";
delete[] url;
}
int main(int argc, char** argv)
{
//設置環境
UsageEnvironment* env;
Boolean reuseFirstSource = False;//如果為“true”則其他接入的客戶端跟第一個客戶端看到一樣的視頻流，否則其他客戶端接入的時候將重新播放
TaskScheduler* scheduler = BasicTaskScheduler::createNew();
env = BasicUsageEnvironment::createNew(*scheduler);
//創建RTSP服務器
UserAuthenticationDatabase* authDB = NULL;
RTSPServer* rtspServer = RTSPServer::createNew(*env, 8554, authDB);
if (rtspServer == NULL) {
*env "Failed to create RTSP server: " env->getResultMsg() "\n";
exit(1);
}
char const* descriptionString= "Session streamed by \&;testOnDemandRTSPServer\&;";
//模擬實時流發送相關變量
int datasize;//數據區長度
unsigned char* databuf;//數據區指針
databuf = (unsigned char*)malloc(1024*1024);
bool dosent;//rtsp發送標志位，為true則發送，否則退出
//從文件中拷貝1M數據到內存中作為實時網絡傳輸內存模擬，如果實時網絡傳輸應該是雙線程結構，記得在這里加上線程鎖
//此外實時傳輸的數據拷貝應該是發生在H264FramedLiveSource文件中，所以這里只是自上往下的傳指針過去給它
FILE *pf;
fopen_s(pf, "test.264", "rb");
fread(databuf, 1, BUFSIZE, pf);
datasize = BUFSIZE;
dosent = true;
fclose(pf);
//上面的部分除了模擬網絡傳輸的部分外其他的基本跟live555提供的demo一樣，而下面則修改為網絡傳輸的形式，為此重寫addSubsession的第一個參數相關文件
char const* streamName = "h264ESVideoTest";
ServerMediaSession* sms = ServerMediaSession::createNew(*env, streamName, streamName,descriptionString);
sms->addSubsession(H264LiveVideoServerMediaSubssion::createNew(*env, reuseFirstSource, datasize, databuf,dosent));//修改為自己實現的H264LiveVideoServerMediaSubssion
rtspServer->addServerMediaSession(sms);
announceStream(rtspServer, sms, streamName);//提示用戶輸入連接信息
env->taskScheduler().doEventLoop(); //循環等待連接
free(databuf);//釋放掉內存
return 0;
}
自定義H264VideoFileServerMediaSubsession類
H264VideoFileServerMediaSubsession.hh
#ifndef _H264_LIVE_VIDEO_SERVER_MEDIA_SUBSESSION_HH
#define _H264_LIVE_VIDEO_SERVER_MEDIA_SUBSESSION_HH
#include "H264VideoFileServerMediaSubsession.hh"
class H264LiveVideoServerMediaSubssion : public H264VideoFileServerMediaSubsession {
public:
static H264LiveVideoServerMediaSubssion* createNew(UsageEnvironment env, Boolean reuseFirstSource, int *datasize, unsigned char* databuf, bool *dosent);
protected: // we're a virtual base class
H264LiveVideoServerMediaSubssion(UsageEnvironment env, Boolean reuseFirstSource, int *datasize, unsigned char* databuf, bool *dosent);
~H264LiveVideoServerMediaSubssion();
protected: // redefined virtual functions
FramedSource* createNewStreamSource(unsigned clientSessionId,unsigned estBitrate);
public:
char fFileName[100];
int *Server_datasize;//數據區大小指針
unsigned char* Server_databuf;//數據區指針
bool *Server_dosent;//發送標示
};
#endifH264VideoFileServerMediaSubsession.cpp
#include "H264LiveVideoServerMediaSubssion.hh"
#include "H264FramedLiveSource.hh"
#include "H264VideoStreamFramer.hh"
H264LiveVideoServerMediaSubssion* H264LiveVideoServerMediaSubssion::createNew(UsageEnvironment env, Boolean reuseFirstSource, int *datasize, unsigned char* databuf, bool *dosent)
{
return new H264LiveVideoServerMediaSubssion(env, reuseFirstSource, datasize, databuf, dosent);
}
H264LiveVideoServerMediaSubssion::H264LiveVideoServerMediaSubssion(UsageEnvironment env, Boolean reuseFirstSource, int *datasize, unsigned char* databuf, bool *dosent)
: H264VideoFileServerMediaSubsession(env, fFileName, reuseFirstSource)//H264VideoFileServerMediaSubsession不是我們需要修改的文件，
//但是我們又要用它來初始化我們的函數，
//所以給個空數組進去即可
{
Server_datasize = datasize;//數據區大小指針
Server_databuf = databuf;//數據區指針
Server_dosent = dosent;//發送標示
}
H264LiveVideoServerMediaSubssion::~H264LiveVideoServerMediaSubssion()
{
}
FramedSource* H264LiveVideoServerMediaSubssion::createNewStreamSource(unsigned clientSessionId, unsigned estBitrate)
{
/* Remain to do : assign estBitrate */
estBitrate = 1000; // kbps, estimate
//創建視頻源
H264FramedLiveSource* liveSource = H264FramedLiveSource::createNew(envir(), Server_datasize, Server_databuf, Server_dosent);
if (liveSource == NULL)
{
return NULL;
}
// Create a framer for the Video Elementary Stream:
return H264VideoStreamFramer::createNew(envir(), liveSource);
}
自定義H264FramedLiveSource類
H264FramedLiveSource.hh
#ifndef _H264FRAMEDLIVESOURCE_HH
#define _H264FRAMEDLIVESOURCE_HH
#include FramedSource.hh>
class H264FramedLiveSource : public FramedSource
{
public:
static H264FramedLiveSource* createNew(UsageEnvironment env, int *datasize, unsigned char* databuf, bool *dosent, unsigned preferredFrameSize = 0, unsigned playTimePerFrame = 0);
protected:
H264FramedLiveSource(UsageEnvironment env, int *datasize, unsigned char* databuf, bool *dosent, unsigned preferredFrameSize, unsigned playTimePerFrame);
~H264FramedLiveSource();
private:
virtual void doGetNextFrame();
int TransportData(unsigned char* to, unsigned maxSize);
protected:
int *Framed_datasize;//數據區大小指針
unsigned char *Framed_databuf;//數據區指針
bool *Framed_dosent;//發送標示
int readbufsize;//記錄已讀取數據區大小
int bufsizel;//記錄數據區大小
};
#endifH264FramedLiveSource.cpp
#include "H264FramedLiveSource.hh"
H264FramedLiveSource::H264FramedLiveSource(UsageEnvironment env, int *datasize, unsigned char* databuf, bool *dosent, unsigned preferredFrameSize, unsigned playTimePerFrame)
: FramedSource(env)
{
Framed_datasize = datasize;//數據區大小指針
Framed_databuf = databuf;//數據區指針
Framed_dosent = dosent;//發送標示
}
H264FramedLiveSource* H264FramedLiveSource::createNew(UsageEnvironment env, int *datasize, unsigned char* databuf, bool *dosent, unsigned preferredFrameSize, unsigned playTimePerFrame)
{
H264FramedLiveSource* newSource = new H264FramedLiveSource(env, datasize, databuf, dosent, preferredFrameSize, playTimePerFrame);
return newSource;
}
H264FramedLiveSource::~H264FramedLiveSource()
{
}
void H264FramedLiveSource::doGetNextFrame()
{
if (*Framed_dosent == true)
{
*Framed_dosent = false;
bufsizel = *Framed_datasize;
readbufsize = 0;
fFrameSize = fMaxSize;
memcpy(fTo, Framed_databuf + readbufsize, fFrameSize);
readbufsize += fFrameSize;
}
else
{
if (bufsizel - readbufsize>fMaxSize)
{
fFrameSize = fMaxSize;
memcpy(fTo, Framed_databuf + readbufsize, fFrameSize);
readbufsize += fFrameSize;
}
else
{
memcpy(fTo, Framed_databuf + readbufsize, bufsizel - readbufsize);
*Framed_dosent = true;
}
}
nextTask() = envir().taskScheduler().scheduleDelayedTask(0,(TaskFunc*)FramedSource::afterGetting, this);//表示延遲0秒后再執行 afterGetting 函數
return;
}
