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• Revision 2740507142 : Merge "[svc] 1. Add two pass RC options in vp9_spatial_scalable_encoder. 2. Add

  7 mars 2014, par Minghai Shang

  Changed Paths :
   Modify /examples.mk

  
  
  Merge "[svc] 1. Add two pass RC options in vp9_spatial_scalable_encoder.
  2. Add read/write for RC stats file The two pass RC for svc does not work yet.
  This is just the first step. We need further development to make it working.
  Change-Id : I8ef0e177dff0b5ed3c97a916beea5123717cc6f2"

• Reading h264 or h265 stream with ffmpeg/OpenCV : Which is faster ?

  25 novembre 2020, par suckss

  I'm using OpenCV with ffmpeg support to read a RTSP stream coming from an IP camera and then to write the frames to a video. The problem is that the frame size is 2816x2816 at 20 fps i.e. there's a lot of data coming in.

  


  I noticed that there was a significant delay in the stream, so I set the buffer size of the cv::VideoCapture object to 1, because I thought that the frames might just get stuck in the buffer instead of being grabbed and processed. This however just caused for frames to be dropped instead.

  


  My next move was to experiment a bit with the frame size/fps and the encoding of the video that I'm writing. All of those things helped to improve the situation, but in the long run I still have to use a frame size of 2816x2816 and support up to 20 fps, so I can't set it lower sadly.

  


  That's where my question comes in : given the fact that the camera stream is going to be either h264 or h265, which one would be read faster by the cv::VideoCapture object ? And how should I encode the video I'm writing in order to minimize the time spent decoding/encoding frames ?

  


  That's the code I'm using for reference :

  


  using namespace cv;
int main(int argc, char** argv)
{
    VideoCapture cap;
    cap.set(CAP_PROP_BUFFERSIZE, 1); // internal buffer will now store only 1 frames

    if (!cap.open("rtsp://admin:admin@1.1.1.1:554/stream")) {
        return -1;
    }
    VideoWriter videoWr;
    Mat frame;
    cap >> frame;
    //int x264 = cv::VideoWriter::fourcc('x', '2', '6', '4'); //I was trying different options
    int x264 = cv::VideoWriter::fourcc('M', 'J', 'P', 'G');
    videoWr = cv::VideoWriter("test_video.avi", 0, 0, 20, frame.size(), true);

    namedWindow("test", WINDOW_NORMAL);
    cv::resizeWindow("test", 1024, 768);
    
    for (;;)
    {
        cap >> frame;
        if (frame.empty()) break; // end of video stream
        
        imshow("test", frame);
        if (waitKey(10) == 27) break; 
        videoWr << frame;
        
    }

    return 0;
}


  


• cv::cudacodec::VideoReader unable to Play rtsp stream

  22 février 2018, par Pawan

  System information

  • OpenCV => 3.3.0
  • Operating System / Platform => Ubuntu 16.04, x86_64
  • Compiler => gcc version 5.4.1 20160904
  • Cuda => 8.0
  • Nvidia card => GTX 1080 Ti
  • ffmpeg details
    • libavutil 55. 74.100 / 55. 74.100
    • libavcodec 57.103.100 / 57.103.100
    • libavformat 57. 77.100 / 57. 77.100
    • libavdevice 57. 7.101 / 57. 7.101
    • libavfilter 6.100.100 / 6.100.100
    • libswscale 4. 7.103 / 4. 7.103
    • libswresample 2. 8.100 / 2. 8.100

  Detailed description

  i am trying to play a rtsp stream using cudacodec::VideoReader

  Rtsp Stream Details ( from vlc )

  

  this stream plays fine in vlc and cv::VideoCapture but when i try to play it in cudacodec::VideoReader i get a error saying :

  OpenCV Error: Gpu API call (CUDA_ERROR_FILE_NOT_FOUND [Code = 301]) in CuvidVideoSource, file /home/deep/Development/libraries/opencv/opencv/modules/cudacodec/src/cuvid_video_source.cpp, line 66

  OpenCV Error: Assertion failed (init_MediaStream_FFMPEG()) in FFmpegVideoSource, file /home/deep/Development/libraries/opencv/opencv/modules/cudacodec/src/ffmpeg_video_source.cpp, line 101

  Steps to reproduce

  #include <iostream>
  
  #include "opencv2/opencv_modules.hpp"
  
  
  
  #if defined(HAVE_OPENCV_CUDACODEC)
  
  
  
  #include <opencv2></opencv2>core.hpp>
  
  #include <opencv2></opencv2>cudacodec.hpp>
  
  #include <opencv2></opencv2>highgui.hpp>
  
  
  
  int main(int argc, const char* argv[])
  
  {
  
      const std::string fname = "rtsp://admin:admin@192.168.1.13/media/video2";
  
  
  
      cv::namedWindow("GPU", cv::WINDOW_NORMAL);
  
  
  
      cv::cuda::GpuMat d_frame;
  
      cv::Ptr d_reader = cv::cudacodec::createVideoReader(fname);
  
  
  
      for (;;)
  
      {
  
  
  
          if (!d_reader->nextFrame(d_frame))
  
              break;
  
  
  
          cv::Mat frame;
  
          d_frame.download(frame);
  
          cv::imshow("GPU", frame);
  
  
  
          if (cv::waitKey(3) > 0)
  
              break;
  
      }
  
      return 0;
  
  }
  
  
  
  #else
  
  int main()
  
  {
  
      std::cout &lt;&lt; "OpenCV was built without CUDA Video decoding support\n" &lt;&lt; std::endl;
  
      return 0;
  
  }
  
  #endif
  
  </iostream>

  I tried debugging it using GDB and saw that in ffmpeg_video_source.cpp bool init_MediaStream_FFMPEG() directly returns without checking the if condition.

  GDB output

  cv::cudacodec::detail::FFmpegVideoSource::FFmpegVideoSource 
  
  (this=0x402a20 <_start>, fname=...) at /home/deep/Development/libraries/opencv/opencv/modules/cudacodec/src/ffmpeg_video_source.cpp:98
  
  98      cv::cudacodec::detail::FFmpegVideoSource::FFmpegVideoSource(const String& fname) :
  
  (gdb) n
  
  99          stream_(0)
  
  (gdb) n
  
  101         CV_Assert( init_MediaStream_FFMPEG() );
  
  (gdb) s
  
  (anonymous namespace)::init_MediaStream_FFMPEG () at /home/deep/Development/libraries/opencv/opencv/modules/cudacodec/src/ffmpeg_video_source.cpp:94
  
  94              return initialized;
  
  (gdb) display initialized
  
  4: initialized = false
  
  (gdb) s
  
  95          }

  UPDATE :

  I have solved the problem. solution link