Gstreamer 使用

Gstreamer安装#

安装依赖包#

sudo apt-get install gtk-doc-tools libgstreamer1.0-0 gstreamer1.0-plugins-base gstreamer1.0-plugins-good gstreamer1.0-plugins-bad gstreamer1.0-plugins-ugly gstreamer1.0-libav gstreamer1.0-doc gstreamer1.0-tools gstreamer1.0-x gstreamer1.0-alsa gstreamer1.0-gl gstreamer1.0-gtk3 gstreamer1.0-qt5 gstreamer1.0-pulseaudio

查看版本信息

#若成功，则有对应版本信息
gst-inspect-1.0 --version

Gstreamer推流--(gst-rstp-sever)#

下载、编译 gst-rtsp-server#

git clone git://anongit.freedesktop.org/gstreamer/gst-rtsp-server
cd gst-rtsp-server
./autogen.sh 
make

进入examples目录就能看到已经编译好的各种示例程序以及源码。

如果编译错误

configure: error: You need to have gtk-doc >= 1.12 installed to build GStreamer RTSP Server Library
  configure failed

安装gtk-doc

sudo apt-get install gtk-doc-tools

推流#

 cd examples
./test-launch "( videotestsrc ! x264enc ! rtph264pay name=pay0 pt=96 )"

Opencv拉流解码#

测试在NVIDA Jetson TX2上拉流解码，硬解码和gpu使用

参考 https://blog.csdn.net/hello_dear_you/article/details/129290712

查看 opencv 是否支持 gstreamer#

opencv 中可以通过调用 getBuildInformance 函数查看 opencv 的编译情况，具体如下所示：

#include <opencv2/opencv.hpp>

int main(void)
{
  std::cout << cv::getBuildInformation() << std::endl;
}

通过运行上述命令可以得到如下输出，其中 Video I/O 中可以找到 Gstreamer 选项是否打开。

Gstreamer软解码#

默认使用cpu进行软解码

#include <opencv2/core.hpp>
#include <opencv2/videoio.hpp>
#include <opencv2/highgui.hpp>
#include <iostream>
#include <stdio.h>
#include <string>
using namespace cv;
using namespace std;
int main(int, char**)
{
    Mat frame;
    //--- INITIALIZE VIDEOCAPTURE
    VideoCapture cap;
    string rtsp_url = "rtsp://admin:password@192.168.170.xxx:554";
    int apiID = cv::CAP_ANY;      // 0 = autodetect default API
    // open rtsp stream using selected API
    cap.open(rtsp_url, apiID);
    // check if we succeeded
    if (!cap.isOpened()) {
        cerr << "ERROR! Unable to open camera\n";
        return -1;
    }
    //--- GRAB AND WRITE LOOP
    cout << "Start grabbing" << endl
        << "Press any key to terminate" << endl;
    for (;;)
    {
        // wait for a new frame from camera and store it into 'frame'
        cap.read(frame);
        // check if we succeeded
        if (frame.empty()) {
            cerr << "ERROR! blank frame grabbed\n";
            break;
        }
        // show live and wait for a key with timeout long enough to show images
        imshow("Live", frame);
        if (waitKey(5) >= 0)
            break;
    }
    // the camera will be deinitialized automatically in VideoCapture destructor
    return 0;
}

Gstreamer Jetson硬解码#

gstreamer 进行硬件解码的流程如下图所示：

demo代码

#include <opencv2/opencv.hpp>
#include <iostream>
#include <chrono>


int main()
{
    using std::chrono::steady_clock;
    typedef std::chrono::milliseconds milliseconds_type;
    const int interval = 15;

    std::stringstream ss;
    std::string rtsp_url = "rtsp://admin:password@192.168.170.xxx:554";
    size_t latency = 200;
    size_t frame_width = 1920;
    size_t frame_height = 1080;
    size_t framerate  = 15;

    ss << "rtspsrc location=" << rtsp_url << " latency=" << latency << " ! application/x-rtp, media=video, encoding-name=H264 "
       << "! rtph264depay ! video/x-h264, clock-rate=90000, width=" << frame_width << ", height=" << frame_height << ", framerate="
       << framerate << "/1 ! nvv4l2decoder ! video/x-raw(memory:NVMM), width=" << frame_width << ", height=" << frame_height 
       << ", framerate=" << framerate << "/1 ! nvvideoconvert ! video/x-raw, format=BGRx ! videoconvert ! video/x-raw, format=BGR ! appsink";
    std::cout << ss.str() << std::endl;

    cv::VideoCapture cap = cv::VideoCapture(ss.str(), cv::CAP_GSTREAMER);
    if(!cap.isOpened())
    {
        std::cerr << "error to open camera." << std::endl;
        return -1;
    }
    std::cout << cv::getBuildInformation() << std::endl;
    cv::Mat frame ;
    steady_clock::time_point start = steady_clock::now();
    size_t frame_idx = 0;

    while(1)
    {
        bool ret = cap.read(frame);
        if(ret)
        {
            // cv::imwrite("tmp.jpg", frame);
            ++frame_idx;
        }
        if(frame_idx % interval == 0)
        {
            steady_clock::time_point end = steady_clock::now();
            milliseconds_type span = std::chrono::duration_cast<milliseconds_type>(end - start) ;
            std::cout << "it took " << span.count() / frame_idx << " millisencods." << std::endl;
            start = end;
        }
    }
    return 0;
}