live555库中，实现了h264、h265流的传输，但是没有对于mjpeg流的传输，遂笔者基于live555库实现mjpeg流传输，以下为代码及其解析。
一、代码思路
如下图，根据官网（http://www.live555.com/）中邮件列表中关于jpeg流传输的问答中可知，如要实现mjpeg流传输，需要实现doGetNextFrame()、type()、qFactor()、width()、height()这几个函数。
在本文代码中，demo仿照testH265VideoStreamer.cpp编写。
width()，height()所需信息通过解析jpeg头可以获得，关于jpeg格式可以参考这篇博客（https://blog.csdn.net/fengbingchun/article/details/103528160）。在这里不再赘述。下面直接上代码
二、代码
如果嫌麻烦不想看，源码压缩包在这里。（https://download.csdn.net/download/Di_Wong/12601695）
（1）testMJPEGVideoStreamer.cpp
此为demo文件，使用前将变量inputFileName改为自己的文件，destinationAddress.s_addr改为VLC所在ip（如我用自己电脑打开地址，则改为我自己电脑ip）
该demo仿照testH265VideoStreamer.cpp编写，为基于多播方式的流媒体传输。
#include "liveMedia.hh"
#include "BasicUsageEnvironment.hh"
#include "GroupsockHelper.hh"
#include "MJPEGVideoSource.hh"
UsageEnvironment* env;
char const* inputFileName = "CrossGuateTL.mjpeg.avi";
MJPEGVideoSource* videoSource;
RTPSink* videoSink;
void play(); // forward
int main(int argc, char** argv) {
// Begin by setting up our usage environment:
TaskScheduler* scheduler = BasicTaskScheduler::createNew();
env = BasicUsageEnvironment::createNew(*scheduler);
// Create 'groupsocks' for RTP and RTCP:
struct in_addr destinationAddress;
// change to your ip!!
destinationAddress.s_addr = our_inet_addr("192.168.16.1");
// destinationAddress.s_addr = chooseRandomIPv4SSMAddress(*env);
// Note: This is a multicast address. If you wish instead to stream
// using unicast, then you should use the "testOnDemandRTSPServer"
// test program - not this test program - as a model.
const unsigned short rtpPortNum = 18888;
const unsigned short rtcpPortNum = rtpPortNum+1;
const unsigned char ttl = 255;
const Port rtpPort(rtpPortNum);
const Port rtcpPort(rtcpPortNum);
Groupsock rtpGroupsock(*env, destinationAddress, rtpPort, ttl);
rtpGroupsock.multicastSendOnly(); // we're a SSM source
Groupsock rtcpGroupsock(*env, destinationAddress, rtcpPort, ttl);
rtcpGroupsock.multicastSendOnly(); // we're a SSM source
// Create a 'JPEG Video RTP' sink from the RTP 'groupsock':
videoSink = JPEGVideoRTPSink::createNew(*env, &rtpGroupsock);
// Create (and start) a 'RTCP instance' for this RTP sink:
const unsigned estimatedSessionBandwidth = 5000; // in kbps; for RTCP b/w share
const unsigned maxCNAMElen = 100;
unsigned char CNAME[maxCNAMElen+1];
gethostname((char*)CNAME, maxCNAMElen);
CNAME[maxCNAMElen] = '
#include "liveMedia.hh"
#include "BasicUsageEnvironment.hh"
#include "GroupsockHelper.hh"
#include "MJPEGVideoSource.hh"
UsageEnvironment* env;
char const* inputFileName = "CrossGuateTL.mjpeg.avi";
MJPEGVideoSource* videoSource;
RTPSink* videoSink;
void play(); // forward
int main(int argc, char** argv) {
// Begin by setting up our usage environment:
TaskScheduler* scheduler = BasicTaskScheduler::createNew();
env = BasicUsageEnvironment::createNew(*scheduler);
// Create 'groupsocks' for RTP and RTCP:
struct in_addr destinationAddress;
// change to your ip!!
destinationAddress.s_addr = our_inet_addr("192.168.16.1");
// destinationAddress.s_addr = chooseRandomIPv4SSMAddress(*env);
// Note: This is a multicast address. If you wish instead to stream
// using unicast, then you should use the "testOnDemandRTSPServer"
// test program - not this test program - as a model.
const unsigned short rtpPortNum = 18888;
const unsigned short rtcpPortNum = rtpPortNum+1;
const unsigned char ttl = 255;
const Port rtpPort(rtpPortNum);
const Port rtcpPort(rtcpPortNum);
Groupsock rtpGroupsock(*env, destinationAddress, rtpPort, ttl);
rtpGroupsock.multicastSendOnly(); // we're a SSM source
Groupsock rtcpGroupsock(*env, destinationAddress, rtcpPort, ttl);
rtcpGroupsock.multicastSendOnly(); // we're a SSM source
// Create a 'JPEG Video RTP' sink from the RTP 'groupsock':
videoSink = JPEGVideoRTPSink::createNew(*env, &rtpGroupsock);
// Create (and start) a 'RTCP instance' for this RTP sink:
const unsigned estimatedSessionBandwidth = 5000; // in kbps; for RTCP b/w share
const unsigned maxCNAMElen = 100;
unsigned char CNAME[maxCNAMElen+1];
gethostname((char*)CNAME, maxCNAMElen);
CNAME[maxCNAMElen] = '\0'; // just in case
RTCPInstance* rtcp = RTCPInstance::createNew(*env, &rtcpGroupsock,
estimatedSessionBandwidth, CNAME,
videoSink, NULL /* we're a server */,
True /* we're a SSM source */);
// Note: This starts RTCP running automatically
RTSPServer* rtspServer = RTSPServer::createNew(*env, 8554);
if (rtspServer == NULL) {
*env << "Failed to create RTSP server: " << env->getResultMsg() << "\n";
exit(1);
}
ServerMediaSession* sms = ServerMediaSession::createNew(*env, "testStream", inputFileName,"Session streamed by \"testMJPEGVideoStreamer\"",
True /*SSM*/);
sms->addSubsession(PassiveServerMediaSubsession::createNew(*videoSink, rtcp));
rtspServer->addServerMediaSession(sms);
char* url = rtspServer->rtspURL(sms);
*env << "Play this stream using the URL \"" << url << "\"\n";
delete[] url;
// Start the streaming:
*env << "Beginning streaming...\n";
play();
env->taskScheduler().doEventLoop(); // does not return
return 0; // only to prevent compiler warning
}
void afterPlaying(void* /*clientData*/) {
*env << "...done reading from file\n";
videoSink->stopPlaying();
Medium::close(videoSource);
// Note that this also closes the input file that this source read from.
// Start playing once again:
play();
}
void play() {
// Open the input file as a 'byte-stream file source':
ByteStreamFileSource* fileSource = ByteStreamFileSource::createNew(*env, inputFileName);
if (fileSource == NULL) {
*env << "Unable to open file \"" << inputFileName
<< "\" as a byte-stream file source\n";
exit(1);
}
FramedSource* videoES = fileSource;
// Create a framer for the Video Elementary Stream:
videoSource = MJPEGVideoSource::createNew(*env, videoES);
// Finally, start playing:
*env << "Beginning to read from file...\n";
videoSink->startPlaying(*videoSource, afterPlaying, videoSink);
}
'; // just in case
RTCPInstance* rtcp = RTCPInstance::createNew(*env, &rtcpGroupsock,
estimatedSessionBandwidth, CNAME,
videoSink, NULL /* we're a server */,
True /* we're a SSM source */);
// Note: This starts RTCP running automatically
RTSPServer* rtspServer = RTSPServer::createNew(*env, 8554);
if (rtspServer == NULL) {
*env << "Failed to create RTSP server: " << env->getResultMsg() << "\n";
exit(1);
}
ServerMediaSession* sms = ServerMediaSession::createNew(*env, "testStream", inputFileName,"Session streamed by \"testMJPEGVideoStreamer\"",
True /*SSM*/);
sms->addSubsession(PassiveServerMediaSubsession::createNew(*videoSink, rtcp));
rtspServer->addServerMediaSession(sms);
char* url = rtspServer->rtspURL(sms);
*env << "Play this stream using the URL \"" << url << "\"\n";
delete[] url;
// Start the streaming:
*env << "Beginning streaming...\n";
play();
env->taskScheduler().doEventLoop(); // does not return
return 0; // only to prevent compiler warning
}
void afterPlaying(void* /*clientData*/) {
*env << "...done reading from file\n";
videoSink->stopPlaying();
Medium::close(videoSource);
// Note that this also closes the input file that this source read from.
// Start playing once again:
play();
}
void play() {
// Open the input file as a 'byte-stream file source':
ByteStreamFileSource* fileSource = ByteStreamFileSource::createNew(*env, inputFileName);
if (fileSource == NULL) {
*env << "Unable to open file \"" << inputFileName
<< "\" as a byte-stream file source\n";
exit(1);
}
FramedSource* videoES = fileSource;
// Create a framer for the Video Elementary Stream:
videoSource = MJPEGVideoSource::createNew(*env, videoES);
// Finally, start playing:
*env << "Beginning to read from file...\n";
videoSink->startPlaying(*videoSource, afterPlaying, videoSink);
}
（2）MJPEGVideoSource.hh
// live header
#include "JPEGVideoSource.hh"
/*!*****************************************************************************
* \brief MJPEG Video Source (RFC 2345)
*************************************************************************************/
class MJPEGVideoSource : public JPEGVideoSource
{
public:
static MJPEGVideoSource* createNew (UsageEnvironment& env, FramedSource* source)
{
return new MJPEGVideoSource(env,source);
}
public:
virtual void doGetNextFrame();
static void afterGettingFrameSub(void* clientData, unsigned frameSize,unsigned numTruncatedBytes,struct timeval presentationTime,unsigned durationInMicroseconds)
{
MJPEGVideoSource* source = (MJPEGVideoSource*)clientData;
source->afterGettingFrame(frameSize, numTruncatedBytes, presentationTime, durationInMicroseconds);
}
void afterGettingFrame(unsigned frameSize,unsigned numTruncatedBytes,struct timeval presentationTime,unsigned durationInMicroseconds);
virtual u_int8_t type() { return 1; };
virtual u_int8_t qFactor() { return 128; };
virtual u_int8_t width() { return m_width; };
virtual u_int8_t height() { return m_height; };
u_int8_t const* quantizationTables( u_int8_t& precision, u_int16_t& length );
protected:
MJPEGVideoSource(UsageEnvironment& env, FramedSource* source);
virtual ~MJPEGVideoSource();
protected:
FramedSource* m_inputSource;
u_int8_t m_width;
u_int8_t m_height;
u_int8_t m_qTable[128];
bool m_qTable0Init;
bool m_qTable1Init;
};
（3）MJPEGVideoSource.cpp
// project header
#include "MJPEGVideoSource.hh"
/*!*****************************************************************************
* \brief Constructor
*************************************************************************************/
MJPEGVideoSource::MJPEGVideoSource(UsageEnvironment& env, FramedSource* source) :
JPEGVideoSource(env),
m_inputSource(source),
m_width(0),
m_height(0),
m_qTable0Init(false),
m_qTable1Init(false)
{
}
/*!*****************************************************************************
* \brief Destructor
*************************************************************************************/
MJPEGVideoSource::~MJPEGVideoSource()
{
if (m_inputSource)
{
Medium::close(m_inputSource);
}
}
/*!*****************************************************************************
* \brief Ask for a frame from the source
*************************************************************************************/
void MJPEGVideoSource::doGetNextFrame()
{
if (m_inputSource)
{
m_inputSource->getNextFrame(fTo, fMaxSize, afterGettingFrameSub, this, FramedSource::handleClosure, this);
}
}
/*!*****************************************************************************
* \brief source callback
*************************************************************************************/
void MJPEGVideoSource::afterGettingFrame(unsigned frameSize,unsigned numTruncatedBytes,struct timeval presentationTime,unsigned durationInMicroseconds)
{
int headerSize = 0;
bool headerOk = false;
for (unsigned int i = 0; i < frameSize ; ++i)
{
// SOF
if ( (i+8) < frameSize && fTo[i] == 0xFF && fTo[i+1] == 0xC0 )
{
m_height = (fTo[i+5]<<5)|(fTo[i+6]>>3);
m_width = (fTo[i+7]<<5)|(fTo[i+8]>>3);
}
// DQT
if ( (i+5+64) < frameSize && fTo[i] == 0xFF && fTo[i+1] == 0xDB)
{
if (fTo[i+4] ==0)
{
memcpy(m_qTable, fTo + i + 5, 64);
m_qTable0Init = true;
}
else if (fTo[i+4] ==1)
{
memcpy(m_qTable + 64, fTo + i + 5, 64);
m_qTable1Init = true;
}
}
// End of header
if ( (i+1) < frameSize && fTo[i] == 0x3F && fTo[i+1] == 0x00 )
{
headerOk = true;
headerSize = i+2;
break;
}
}
if (headerOk)
{
fFrameSize = frameSize - headerSize;
memcpy( fTo, fTo + headerSize, fFrameSize );
}
fNumTruncatedBytes = numTruncatedBytes;
fPresentationTime = presentationTime;
fDurationInMicroseconds = durationInMicroseconds;
afterGetting(this);
}
/*!*****************************************************************************
* \brief return quantification tables
*************************************************************************************/
u_int8_t const* MJPEGVideoSource::quantizationTables( u_int8_t& precision, u_int16_t& length )
{
length = 0;
precision = 0;
if ( m_qTable0Init && m_qTable1Init )
{
precision = 8;
length = sizeof(m_qTable);
}
return m_qTable;
}
三、使用
运行testMJPEGVideoStreamer，将播放地址在VLC客户端播放即可。
本文地址：https://blog.csdn.net/Di_Wong/article/details/107284635
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