mjpg-streamer網路攝影機遠程傳輸UVC

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  mjpg-streamer網路攝影機遠程傳輸UVC

1 下載原始碼 

mjpg-streamer的原始碼地址  https://github.com/codewithpassion/mjpg-streamer

嵌入式 mini2440版 https://github.com/vfonov/mjpg-streamer

2 編譯 

  mjpg-streamermake

執行

export LD_LIBRARY_PATH="$(pwd)"

./mjpg_streamer -i "./input_uvc.so -y" -o "./output_ http.so -w ./www" 

電腦端 用Firefox瀏覽器 輸入  
http://192.168.1.17:8080/?

action=stream

當中 192.168.1.17依據實際情況輸入

2原始碼分析 

從main開始 位於Mjpg_streamer.c 

getopt_long_only：解析輸入的參數global.in.init = dlsym(global.in.handle, "input_init"); // 讓 global.in.init = input_init dlsym 取動態對象地址

input_init (input_uvc.c )-->if (init_videoIn(videoIn, dev, width, height, fps, format, 1) < 0)        init_videoIn(V4l2uvc.c (plugins\input_uvc)             init_v4l2
global.in.run = dlsym(global.in.handle, "input_run");

 input_run(input_uvc.c )

     -->pthread_create(&cam, 0, cam_thread, NULL);

        void *cam_thread( void *arg ) 

             uvcGrab(videoIn) 

            if (videoIn->formatIn == V4L2_PIX_FMT_YUYV)

                  pglobal->size = compress_yuyv_to_jpeg(videoIn, pglobal->buf, videoIn->framesizeIn, gquality);

else

  {

   pglobal->size = memcpy_picture(pglobal->buf, videoIn->tmpbuffer, videoIn->buf.bytesused);

  }

global.out[i].init = dlsym(global.out[i].handle, "output_init");   output_init(   output_http.c)

 servers[param->id].id = param->id; servers[param->id].pglobal = param->global; servers[param->id].conf.port = port; servers[param->id].conf.credentials = credentials; servers[param->id].conf.www_folder = www_folder; servers[param->id].conf.nocommands = nocommands;

global.out[i].stop = dlsym(global.out[i].handle, "output_stop");

output_stop

pthread_cancel(servers[id].threadID);

global.out[i].run = dlsym(global.out[i].handle, "output_run"); 
    output_run(output_http.c)         pthread_create(&(servers[id].threadID), NULL, server_thread, &(servers[id])); // 建立一個線程 server_thread         pthread_detach(servers[id].threadID); // 等待線程結束,以便回收
            server_thread (Httpd.c\plugins\output_http)                    ->  client_thread                        if ( strstr(buffer, "GET /?action=snapshot") != NULL )

 {

  req.type = A_SNAPSHOT; 

 }

 else if ( strstr(buffer, "GET /?action=stream") != NULL )

 {

  req.type = A_STREAM; 

 }

 else if ( strstr(buffer, "GET /?action=command") != NULL )

 {

                            req.type = A_COMMAND;                    }
        switch ( req.type ){

case A_SNAPSHOT:

   DBG("Request for snapshot\n");

   send_snapshot(lcfd.fd);

   break;

  case A_STREAM:

   DBG("Request for stream\n");

   send_stream(lcfd.fd);

   break;

}

mjpg-streamer網路攝影機遠程傳輸UVC