庖丁解牛-----Live555源码彻底解密(根据OpenRTSP讲解)
OpenRtsp中写H264文件注意的地方：
OpenRtsp客户端包括OpenRtsp.cpp和playCommon.cpp 两个文件
1）接受buffer保存到文件
void H264VideoFileSink::afterGettingFrame(unsignedframeSize,unsignednumTruncatedBytes,structtimeval presentationTime) {
unsigned char const start_code[4] = {0x00, 0x00, 0x00, 0x01};
if (!fHaveWrittenFirstFrame) {
// If we have PPS/SPS NAL units encoded in a "sprop parameter string", prepend these to the file:
unsigned numSPropRecords;
SPropRecord* sPropRecords = parseSPropParameterSets(fSPropParameterSetsStr,numSPropRecords);
for (unsignedi = 0;i < numSPropRecords; ++i) {
addData(start_code, 4,presentationTime);
addData(sPropRecords[i].sPropBytes,sPropRecords[i].sPropLength,presentationTime);
}
delete[] sPropRecords;
fHaveWrittenFirstFrame = True; // for next time
}
// Write the input data to the file, with the start code in front:
addData(start_code, 4,presentationTime);
// Call the parent class to complete the normal file write with the input data:
FileSink::afterGettingFrame(frameSize,numTruncatedBytes,presentationTime);
}
2）获取到路径名
// Create an output file for each desired stream:
char outFileName[1000];
if (singleMedium ==NULL) {
// Output file name is
// "<filename-prefix><medium_name>-<codec_name>-<counter>"
static unsigned streamCounter = 0;
//outFileName为文件名
snprintf(outFileName,sizeofoutFileName,"%s%s-%s-%d",
fileNamePrefix,subsession->mediumName(),
subsession->codecName(), ++streamCounter);
} else {
sprintf(outFileName,"stdout");
}
3）保存文件
void FileSink::afterGettingFrame(unsignedframeSize,
unsigned numTruncatedBytes,
struct timeval presentationTime) {
if (numTruncatedBytes > 0) {
envir() << "FileSink::afterGettingFrame(): The input frame data was too large for our buffer size ("
<< fBufferSize << "). "
<< numTruncatedBytes <<" bytes of trailing data was dropped! Correct this by increasing the \"bufferSize\" parameter in the \"createNew()\" call to at least "
<< fBufferSize + numTruncatedBytes << "\n";
}
addData(fBuffer,frameSize,presentationTime);
if (fOutFid ==NULL ||fflush(fOutFid) ==EOF) {
// The output file has closed. Handle this the same way as if the input source had closed:
if (fSource !=NULL)fSource->stopGettingFrames();
onSourceClosure(this);
return;
}
if (fPerFrameFileNameBuffer !=NULL) {
if (fOutFid !=NULL) {fclose(fOutFid);fOutFid =NULL; }
}
// Then try getting the next frame:
continuePlaying();
}
1） 写文件
void FileSink::addData(unsignedcharconst* data, unsigned dataSize,
struct timeval presentationTime) {
if (fPerFrameFileNameBuffer !=NULL) {
// Special case: Open a new file on-the-fly for this frame
sprintf(fPerFrameFileNameBuffer,"%s-%lu.%06lu",fPerFrameFileNamePrefix,
presentationTime.tv_sec,presentationTime.tv_usec);
fOutFid = OpenOutputFile(envir(), fPerFrameFileNameBuffer);
}
// Write to our file:
#ifdef TEST_LOSS
static unsigned const framesPerPacket = 10;
static unsigned const frameCount = 0;
static Boolean const packetIsLost;
if ((frameCount++)%framesPerPacket == 0) {
packetIsLost = (our_random()%10 == 0); // simulate 10% packet loss #####
}
if (!packetIsLost)
#endif
if (fOutFid !=NULL &&data !=NULL) {
fwrite(data, 1,dataSize,fOutFid);
}
}
其中 unsigned char* fBuffer; 用来保存文件的Buff;
fBuffer = new unsigned char[bufferSize]; 缓冲区的size，默认多少？
#ifndef _H264_VIDEO_FILE_SINK_HH
#define _H264_VIDEO_FILE_SINK_HH
#ifndef _FILE_SINK_HH
#include "FileSink.hh"
#endif
class H264VideoFileSink: public FileSink {
public:
static H264VideoFileSink* createNew(UsageEnvironment&env,char const* fileName,
char const* sPropParameterSetsStr = NULL,
// An optional 'SDP format' string (comma-separated Base64-encoded) representing SPS and/or PPS NAL-units to prepend to the output
unsigned bufferSize = 100000,
BooleanoneFilePerFrame =False);
// See "FileSink.hh" for a description of these parameters.
protected:
H264VideoFileSink(UsageEnvironment&env,FILE* fid,
char const* sPropParameterSetsStr,
unsigned bufferSize, char const* perFrameFileNamePrefix);
// called only by createNew()
virtual ~H264VideoFileSink();
protected: // redefined virtual functions:
virtual void afterGettingFrame(unsignedframeSize,unsignednumTruncatedBytes,structtimeval presentationTime);
private:
char const*fSPropParameterSetsStr;
Boolean fHaveWrittenFirstFrame;
};
#endif
默认的是100k 可以修改，在OpenRtsp中修改unsignedfileSinkBufferSize = 1000000; //modify by zh 100000 to 1000000
OpenRtsp还需要获取帧率的信息，进行录像，帧率的参数可以从OpenRtsp中进行修改;
unsigned movieFPS = 30; // default //帧率信息modify by zhongh 15 to 30
相机1080p的 30帧，每秒1.18M
OpenRtsp将文件写成AVI的代码如下：
else if (outputAVIFile) {
// Create an "AVIFileSink", to write to 'stdout':
//如何将stdout修改成写avi 文件
aviOut = AVIFileSink::createNew(*env, *session,"d:\\test1.avi",
fileSinkBufferSize,
movieWidth,movieHeight,
movieFPS, //帧率
packetLossCompensate);//包丢失补偿;
if (aviOut ==NULL) {
*env << "Failed to create AVI file sink for stdout: " << env->getResultMsg();
shutdown();
}
aviOut->startPlaying(sessionAfterPlaying,NULL);