使用 live555 直播来自 v4l2 的摄像头图像

使用 live555 直播来自 v4l2 的摄像头图像

//具体评论可以参考原文细节；

结合前面的 采集 v4l2 视频, 使用 live555, 通过 rtsp 发布实时流. capture.h, capture.cpp, vcompress.h, vcompress.cpp 需要参考前面几片文章. 这里仅仅贴出 v4l2_x264_service.cpp

 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <assert.h>

 #include <liveMedia.hh>
 #include <BasicUsageEnvironment.hh>
 #include <GroupsockHelper.hh>

 #include <sys/types.h>
 #include <sys/syscall.h>

 #include "capture.h"
 #include "vcompress.h"

 static UsageEnvironment *_env = 0;

 #define SINK_PORT 3030

 #define VIDEO_WIDTH 320
 #define VIDEO_HEIGHT 240
 #define FRAME_PER_SEC 5.0

 pid_t gettid()
 {
     return syscall(SYS_gettid);
 }


 // 使用 webcam + x264
 class WebcamFrameSource : public FramedSource
 {
     void *mp_capture, *mp_compress; // v4l2 + x264 encoder
     int m_started;
     void *mp_token;

 public:
     WebcamFrameSource (UsageEnvironment &env)
         : FramedSource(env)
     {
         fprintf(stderr, "[%d] %s .... calling\n", gettid(), __func__);
         mp_capture = capture_open("/dev/video0", VIDEO_WIDTH, VIDEO_HEIGHT, PIX_FMT_YUV420P);
         if (!mp_capture) {
             fprintf(stderr, "%s: open /dev/video0 err\n", __func__);
             exit(-1);
         }

         mp_compress = vc_open(VIDEO_WIDTH, VIDEO_HEIGHT, FRAME_PER_SEC);
         if (!mp_compress) {
             fprintf(stderr, "%s: open x264 err\n", __func__);
             exit(-1);
         }

         m_started = 0;
         mp_token = 0;
     }

     ~WebcamFrameSource ()
     {
         fprintf(stderr, "[%d] %s .... calling\n", gettid(), __func__);

         if (m_started) {
             envir().taskScheduler().unscheduleDelayedTask(mp_token);
         }

         if (mp_compress)
             vc_close(mp_compress);
         if (mp_capture)
             capture_close(mp_capture);
     }

 protected:
     virtual void doGetNextFrame ()
     {
         if (m_started) return;
         m_started = 1;

         // 根据 fps, 计算等待时间
         double delay = 1000.0 / FRAME_PER_SEC;
         int to_delay = delay * 1000;    // us

         mp_token = envir().taskScheduler().scheduleDelayedTask(to_delay,
                 getNextFrame, this);
     }

 virtual unsigned maxFrameSize() const        // 这个很重要, 如果不设置, 可能导致 getNextFrame() 出现 fMaxSize 小于实际编码帧的情况, 导致图像不完整

 {    return 100*1024; }

 private:
     static void getNextFrame (void *ptr)
     {
         ((WebcamFrameSource*)ptr)->getNextFrame1();
     }

     void getNextFrame1 ()
     {
         // capture:
         Picture pic;
         if (capture_get_picture(mp_capture, &pic) < 0) {
             fprintf(stderr, "==== %s: capture_get_picture err\n", __func__);
             m_started = 0;
             return;
         }

         // compress
         const void *outbuf;
         int outlen;
         if (vc_compress(mp_compress, pic.data, pic.stride, &outbuf, &outlen) < 0) {
             fprintf(stderr, "==== %s: vc_compress err\n", __func__);
             m_started = 0;
             return;
         }

         int64_t pts, dts;
         int key;
         vc_get_last_frame_info(mp_compress, &key, &pts, &dts);

         // save outbuf
         gettimeofday(&fPresentationTime, 0);
         fFrameSize = outlen;
         if (fFrameSize > fMaxSize) {
             fNumTruncatedBytes = fFrameSize - fMaxSize;
             fFrameSize = fMaxSize;
         }
         else {
             fNumTruncatedBytes = 0;
         }

         memmove(fTo, outbuf, fFrameSize);

         // notify
         afterGetting(this);

         m_started = 0;
     }
 };

 class WebcamOndemandMediaSubsession : public OnDemandServerMediaSubsession
 {
 public:
     static WebcamOndemandMediaSubsession *createNew (UsageEnvironment &env, FramedSource *source)
     {
         return new WebcamOndemandMediaSubsession(env, source);
     }

 protected:
     WebcamOndemandMediaSubsession (UsageEnvironment &env, FramedSource *source)
         : OnDemandServerMediaSubsession(env, True) // reuse the first source
     {
         fprintf(stderr, "[%d] %s .... calling\n", gettid(), __func__);
         mp_source = source;
         mp_sdp_line = 0;
     }

     ~WebcamOndemandMediaSubsession ()
     {
         fprintf(stderr, "[%d] %s .... calling\n", gettid(), __func__);
         if (mp_sdp_line) free(mp_sdp_line);
     }

 private:
     static void afterPlayingDummy (void *ptr)
     {
         fprintf(stderr, "[%d] %s .... calling\n", gettid(), __func__);
         // ok
         WebcamOndemandMediaSubsession *This = (WebcamOndemandMediaSubsession*)ptr;
         This->m_done = 0xff;
     }

     static void chkForAuxSDPLine (void *ptr)
     {
         WebcamOndemandMediaSubsession *This = (WebcamOndemandMediaSubsession *)ptr;
         This->chkForAuxSDPLine1();
     }

     void chkForAuxSDPLine1 ()
     {
         fprintf(stderr, "[%d] %s .... calling\n", gettid(), __func__);
         if (mp_dummy_rtpsink->auxSDPLine())
             m_done = 0xff;
         else {
             int delay = 100*1000;   // 100ms
             nextTask() = envir().taskScheduler().scheduleDelayedTask(delay,
                     chkForAuxSDPLine, this);
         }
     }

 protected:
     virtual const char *getAuxSDPLine (RTPSink *sink, FramedSource *source)
     {
         fprintf(stderr, "[%d] %s .... calling\n", gettid(), __func__);
         if (mp_sdp_line) return mp_sdp_line;

         mp_dummy_rtpsink = sink;
         mp_dummy_rtpsink->startPlaying(*source, 0, 0);
         //mp_dummy_rtpsink->startPlaying(*source, afterPlayingDummy, this);
         chkForAuxSDPLine(this);
         m_done = 0;
         envir().taskScheduler().doEventLoop(&m_done);
         mp_sdp_line = strdup(mp_dummy_rtpsink->auxSDPLine());
         mp_dummy_rtpsink->stopPlaying();

         return mp_sdp_line;
     }

     virtual RTPSink *createNewRTPSink(Groupsock *rtpsock, unsigned char type, FramedSource *source)
     {
         fprintf(stderr, "[%d] %s .... calling\n", gettid(), __func__);
         return H264VideoRTPSink::createNew(envir(), rtpsock, type);
     }

     virtual FramedSource *createNewStreamSource (unsigned sid, unsigned &bitrate)
     {
         fprintf(stderr, "[%d] %s .... calling\n", gettid(), __func__);
         bitrate = 500;
         return H264VideoStreamFramer::createNew(envir(), new WebcamFrameSource(envir()));
     }

 private:
     FramedSource *mp_source;    // 对应 WebcamFrameSource
     char *mp_sdp_line;
     RTPSink *mp_dummy_rtpsink;
     char m_done;
 };

 static void test_task (void *ptr)
 {
     fprintf(stderr, "test: task ....\n");
     _env->taskScheduler().scheduleDelayedTask(100000, test_task, 0);
 }

 static void test (UsageEnvironment &env)
 {
     fprintf(stderr, "test: begin...\n");

     char done = 0;
     int delay = 100 * 1000;
     env.taskScheduler().scheduleDelayedTask(delay, test_task, 0);
     env.taskScheduler().doEventLoop(&done);

     fprintf(stderr, "test: end..\n");
 }

 int main (int argc, char **argv)
 {
     // env
     TaskScheduler *scheduler = BasicTaskScheduler::createNew();
     _env = BasicUsageEnvironment::createNew(*scheduler);

     // test
     //test(*_env);

     // rtsp server
     RTSPServer *rtspServer = RTSPServer::createNew(*_env, 8554);
     if (!rtspServer) {
         fprintf(stderr, "ERR: create RTSPServer err\n");
         ::exit(-1);
     }

     // add live stream
     do {
         WebcamFrameSource *webcam_source = 0;

         ServerMediaSession *sms = ServerMediaSession::createNew(*_env, "webcam", 0, "Session from /dev/video0");
         sms->addSubsession(WebcamOndemandMediaSubsession::createNew(*_env, webcam_source));
         rtspServer->addServerMediaSession(sms);

         char *url = rtspServer->rtspURL(sms);
         *_env << "using url \"" << url << "\"\n";
         delete [] url;
     } while (0);

     // run loop
     _env->taskScheduler().doEventLoop();

     return 1;
 }

需要 live555 + libavcodec + libswscale + libx264, client 使用 vlc, mplayer, quicktime, .....