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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/core.hpp>
#include <opencv2/cudacodec.hpp>
#include <opencv2/highgui.hpp>

int main(int argc, const char* argv[])
{
    const std::string fname = "rtsp://admin:[email protected]/media/video2";

    cv::namedWindow("GPU", cv::WINDOW_NORMAL);

    cv::cuda::GpuMat d_frame;
    cv::Ptr<cv::cudacodec::VideoReader> 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 << "OpenCV was built without CUDA Video decoding support\n" << std::endl;
    return 0;
}
#endif

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          }