1  基于rtsp-simple-server的视频推流

rtsp-simple-server是一个rtsp推流服务器，可以与gstreamer或ffmpeg结合进行推流。下载对应平台版本，直接运行即可。

1.1  使用gstreamer命令推流

1.1.1  RTSP视频推流:Camera

/usr/bin/gst-launch-1.0 v4l2src device=/dev/video0 ! videoconvert ! video/x-raw,width=640,height=480,framerate=30/1 ! timeoverlay ! videoconvert ! x264enc ! rtspclientsink location=rtsp://localhost:8554/mystream

1.1.2  RTSP视频推流:Camera简化

/usr/bin/gst-launch-1.0 v4l2src device=/dev/video0 ! timeoverlay ! videoconvert ! x264enc ! rtspclientsink location=rtsp://localhost:8554/mystream

1.1.3  RTSP视频推流:videotestsrc

/usr/bin/gst-launch-1.0 videotestsrc ! video/x-raw,width=1920,height=1080,framerate=30/1 ! timeoverlay ! videoconvert ! x264enc ! rtspclientsink location=rtsp://localhost:8554/mystream

1.2  使用opencv和ffmpeg推流（cuvid硬件编码）

    std::string rtsp_server_url = "rtsp://localhost:8554/live/test_green";

    std::stringstream command;

    command << "ffmpeg ";

    // infile options

    command << "-y "  // overwrite output files

            << "-an " // disable audio

            << "-hwaccel cuvid "

            << "-f rawvideo " // force format to rawvideo

            << "-vcodec rawvideo "  // force video rawvideo ('copy' to copy stream)

            << "-pix_fmt bgr24 "  // set pixel format to bgr24

            << "-s 1920x1080 "  // set frame size (WxH or abbreviation)

            << "-r 30 "; // set frame rate (Hz value, fraction or abbreviation)

    command << "-i - ";

    // outfile options

    command << "-c:v h264_nvenc "  // nvenc Video encoder

            << "-pix_fmt yuv420p "  // set pixel format to yuv420p

            << "-tune:v zerolatency "

            << "-preset fast " // set the h264_nvenc encoding preset to fast

            << "-f rtsp " // force format to flv for rtmp, rtsp for rtsp

            << rtsp_server_url;

    cv::Mat frame;

    // 在子进程中调用 ffmpeg 进行推流

    FILE *fp = nullptr;

    fp = popen(command.str().c_str(), "w");

    int id = 0;

    // 将 cv 读到的每一帧传入子进程

    if (fp != nullptr)

    {

        while (1)

        {

            frame = cv::imread("./2016-04-14-09-25-42.jpg");

            cv::String strFrameId;

            id = (++id) % 10000;

            QString idStr = QString("%1").arg(id);

            strFrameId = idStr.toStdString();

            cv::putText(frame, strFrameId, cv::Point(960,500), cv::HersheyFonts::FONT_ITALIC, 10, cv::Scalar(0,255,0), 3);

            if(frame.empty())

            {

                continue;

            }

            std::cout << frame.size() << std::endl;

            fwrite(frame.data, sizeof(char), frame.total() * frame.elemSize(), fp);

        }

        pclose(fp);

        return EXIT_SUCCESS;

    }

    else

    {

        return EXIT_FAILURE;

    }

1.3  使用opencv和ffmpeg推流（x264软件解码）

    std::string rtsp_server_url = "rtsp://localhost:8554/live/test_green";

    std::stringstream command;

    command << "ffmpeg ";

    // infile options

    command << "-y "  // overwrite output files

            << "-an " // disable audio

            << "-f rawvideo " // force format to rawvideo

            << "-vcodec rawvideo "  // force video rawvideo ('copy' to copy stream)

            << "-pix_fmt bgr24 "  // set pixel format to bgr24

            << "-s 1920x1080 "  // set frame size (WxH or abbreviation)

            << "-r 30 "; // set frame rate (Hz value, fraction or abbreviation)

    command << "-i - ";

    // outfile options

    command << "-c:v libx264 "  // Hyper fast Audio and Video encoder

      << "-pix_fmt yuv420p "  // set pixel format to yuv420p

      << "-tune:v zerolatency "

      << "-preset ultrafast " // set the libx264 encoding preset to ultrafast

      << "-f rtsp " // force format to flv for rtmp, rtsp for rtsp

      << rtsp_server_url;

    cv::Mat frame;

    // 在子进程中调用 ffmpeg 进行推流

    FILE *fp = nullptr;

    fp = popen(command.str().c_str(), "w");

    int id = 0;

    // 将 cv 读到的每一帧传入子进程

    if (fp != nullptr)

    {

        while (1)

        {

            frame = cv::imread("./2016-04-14-09-25-42.jpg");

            cv::String strFrameId;

            id = (++id) % 10000;

            QString idStr = QString("%1").arg(id);

            strFrameId = idStr.toStdString();

            cv::putText(frame, strFrameId, cv::Point(960,500), cv::HersheyFonts::FONT_ITALIC, 10, cv::Scalar(0,255,0), 3);

            if(frame.empty())

            {

                continue;

            }

            std::cout << frame.size() << std::endl;

            fwrite(frame.data, sizeof(char), frame.total() * frame.elemSize(), fp);

        }

        pclose(fp);

        return EXIT_SUCCESS;

    }

    else

    {

        return EXIT_FAILURE;

}

1.4  使用opencv和gstreamer推流

    cv::Mat frame;

    cv::String gst_str = "appsrc ! videoconvert ! x264enc ! rtspclientsink location=rtsp://localhost:8554/live/test_red";

    //cv::String gst_str = "appsrc ! videoconvert ! omxh264enc ! rtspclientsink location=rtsp://localhost:8554/live/test_red";//PC上没有omxh264enc插件，嵌入式平台有

    cv::VideoWriter video_writer(gst_str,cv::CAP_GSTREAMER, 0, 30, cv::Size(1920,1080));

    int id = 0;

    // 将 cv 读到的每一帧传入子进程

    while (1)

    {

        frame = cv::imread("./2016-04-14-09-25-42.jpg");

        cv::String strFrameId;

        id = (++id) % 10000;

        QString idStr = QString("%1").arg(id);

        strFrameId = idStr.toStdString();

        cv::putText(frame, strFrameId, cv::Point(960,500), cv::HersheyFonts::FONT_ITALIC, 10, cv::Scalar(0,255,0), 3);

        if(frame.empty())

        {

            continue;

        }

        std::cout << frame.size() << std::endl;

        //

        video_writer.write(frame);

    }

    return EXIT_SUCCESS;

2  opencv,x264，live555推流

2.1  原理

opencv将视频帧传递给x264进行编码，将输出的264数据流写入管道文件，管道文件放在live555的推流可执行文件live555MediaServer统一目录下。

管道文件为FIFO，写入（推流）和读出（拉流）需要同时进行，否则会阻塞。

2.2  示例代码

    cv::Mat BasePic = cv::imread("./2016-04-14-09-25-42.jpg");

    cv::Mat inputPic;

    cv::resize(BasePic, BasePic, cv::Size(1920, 1080));

    //使用YUV420编码

    cv::cvtColor(BasePic, BasePic, cv::COLOR_BGR2YUV_I420);

    //创建fifo

    ::unlink("/media/user/DATA/zhangchen/live555/live555-latest/live/mediaServer/demo.264");

    ::mkfifo("/media/user/DATA/zhangchen/live555/live555-latest/live/mediaServer/demo.264", O_CREAT | O_EXCL | 660);

    //打开fifo

    int fp_dst = ::open("/media/user/DATA/zhangchen/live555/live555-latest/live/mediaServer/demo.264", O_WRONLY);

    if(fp_dst == NULL)

    {

        ::close(fp_dst);

        return;

    }

    //H264编码设置

    int video_width = 1920;

    int video_height = 1080;

    int res = 0;

    //压缩编码前的图像

    x264_picture_t pic;

    x264_picture_t pic_out;

    //

    x264_t *h;

    int i_frame = 0;

    int i_frame_size = 0;

    //压缩编码后的码流数据

    x264_nal_t *nal;

    int i_nal;

    x264_param_t param;

    res = x264_param_default_preset(¶m, "veryfast", NULL);

    param.i_bitdepth = 8;//编码位数

    param.i_csp = X264_CSP_I420;//编码制式

    param.rc.i_qp_min = 36;//编码质量：越小，视频质量损失越小

    param.rc.i_qp_max = 40;

    param.rc.i_qp_step = 2;

    param.i_width = video_width;//分辨率

    param.i_height = video_height;

    param.i_fps_den = 1;//帧率

    param.i_fps_num = 30;

    param.i_keyint_max = 4;//设置IDR关键帧间隔

    param.i_keyint_min = 1;

    param.b_vfr_input = 0;//固定帧率

    param.b_repeat_headers = 1;//在每个关键帧前放置SPS/PPS

    param.b_annexb = 1;//在NAL单元前放置起始码

    res = x264_param_apply_profile(¶m, "baseline");

    res = x264_picture_alloc(&pic, param.i_csp, param.i_width, param.i_height);

    //打开编码器

    h = x264_encoder_open(¶m);

    if(h == 0)

    {

        return;

    }

    //输出头信息

/*

    i_frame_size = x264_encoder_headers(h, &nal, &i_nal);

    if(i_frame_size < 0)

    {

        return;

    }

    else if(i_frame_size)

    {

        if(!::write(fp_dst, nal->p_payload, i_frame_size))

        {

            return;

        }

    }

*/

    //对视频帧进行编码

    unsigned int luma_size = video_width * video_height;

    unsigned int chroma_size = luma_size / 4;

    for(;;i_frame++)

    {

        //读取输入帧YUV420

        inputPic = BasePic.clone();

        //绘制帧号

        int id = i_frame / 15;

        cv::String strFrameId;

        QString idStr = QString("%1").arg(id);

        strFrameId = idStr.toStdString();

        cv::putText(inputPic, strFrameId, cv::Point(960,500), cv::HersheyFonts::FONT_ITALIC, 10, cv::Scalar(255,0,0), 3);

        //

        memcpy(pic.img.plane[0], inputPic.data, luma_size);

        memcpy(pic.img.plane[1], inputPic.data + luma_size, chroma_size);

        memcpy(pic.img.plane[2], inputPic.data + luma_size + chroma_size, chroma_size);

        //

        pic.i_pts = i_frame;

        i_frame_size = x264_encoder_encode(h, &nal, &i_nal, &pic, &pic_out);

        if(i_frame_size < 0)

        {

            break;

        }

        else if(i_frame_size)

        {

            if(!::write(fp_dst, nal->p_payload, i_frame_size))

            {

                break;

            }

        }

        if(i_frame == (30 * 600))

        {

            break;

        }

    }

/*

    //Flush delayed frames

    while(x264_encoder_delayed_frames(h))

    {

        i_frame_size = x264_encoder_encode(h, &nal, &i_nal, NULL, &pic_out);

        if(i_frame_size < 0)

        {

            break;

        }

        else if(i_frame_size)

        {

            if(!::write(fp_dst, nal->p_payload, i_frame_size))

            {

                break;

            }

        }

    }

*/

    //关闭编码器

    x264_encoder_close(h);

    x264_picture_clean(&pic);

    ::close(fp_dst);