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OpenCVSharp #1733

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loveyou143j opened this issue Jan 11, 2025 · 0 comments
Open

OpenCVSharp #1733

loveyou143j opened this issue Jan 11, 2025 · 0 comments

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@loveyou143j
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loveyou143j commented Jan 11, 2025

HEVC (High Efficiency Video Coding), also known as H.265, is a popular video compression format, and OpenCV provides support for it through the use of FFmpeg. If you are using OpenCVSharp, which is a .NET wrapper for OpenCV, you can enable HEVC codec support by ensuring that OpenCV is built with FFmpeg and the necessary HEVC codecs.

Steps to Enable HEVC Codec Support in OpenCVSharp:

1. Ensure OpenCV is Built with FFmpeg Support

OpenCV requires FFmpeg to handle video codecs like HEVC (H.265). Ensure that OpenCV is built with FFmpeg support and that the FFmpeg library includes the HEVC codec.

  • On Windows, if you're using precompiled OpenCV binaries, ensure you have the correct OpenCV version with FFmpeg support. Some precompiled OpenCV versions might not come with FFmpeg support, so you may need to either:

    • Build OpenCV from source with FFmpeg enabled.
    • Use a custom build of FFmpeg that includes HEVC support.
  • On Linux, you can install FFmpeg with HEVC support via your package manager (e.g., libx265 package for HEVC).

    sudo apt-get install ffmpeg libx265-dev
  • On macOS, FFmpeg with HEVC support can be installed using Homebrew:

    brew install ffmpeg --with-libx265

2. Build OpenCV with FFmpeg and HEVC Support

If you need to build OpenCV with FFmpeg and HEVC support manually, follow these steps:

  • Clone OpenCV and OpenCV contrib repositories:

    git clone --branch 4.x https://github.com/opencv/opencv.git
    git clone --branch 4.x https://github.com/opencv/opencv_contrib.git
  • Build OpenCV with CMake:
    Make sure to configure CMake to enable FFmpeg and HEVC support. Here’s how you can configure it:

    • Enable WITH_FFMPEG=ON in CMake.
    • Ensure the path to FFmpeg is specified (FFMPEG_INCLUDE_DIRS, FFMPEG_LIBRARIES).
    • Ensure FFMPEG is using a version with HEVC support (like libx265).

    Example CMake command:

    cmake -D CMAKE_BUILD_TYPE=Release \
          -D CMAKE_INSTALL_PREFIX=/path/to/installation \
          -D WITH_FFMPEG=ON \
          -D FFMPEG_INCLUDE_DIR=/path/to/ffmpeg/include \
          -D FFMPEG_LIBRARIES=/path/to/ffmpeg/lib \
          ..
  • Install FFmpeg libraries with HEVC support on your machine before building OpenCV.

  • Build and Install OpenCV:
    After configuring CMake, run the following to build and install OpenCV:

    make -j$(nproc)
    sudo make install

3. Using OpenCVSharp with HEVC Support

Once OpenCV is properly built and installed with FFmpeg (including HEVC support), you can use it in OpenCVSharp for reading or writing HEVC encoded videos.

Example of reading a HEVC encoded video using OpenCVSharp:

using OpenCvSharp;

class Program
{
    static void Main(string[] args)
    {
        // Open a HEVC encoded video file
        var capture = new VideoCapture("input_video.hevc");

        // Check if the video is opened successfully
        if (!capture.IsOpened())
        {
            Console.WriteLine("Error: Could not open the video file.");
            return;
        }

        Mat frame = new Mat();
        while (true)
        {
            capture.Read(frame);
            if (frame.Empty())
                break;

            // Display the frame
            Cv2.ImShow("Video", frame);
            if (Cv2.WaitKey(1) == 27)  // Exit on ESC key
                break;
        }

        capture.Release();
        Cv2.DestroyAllWindows();
    }
}

4. Write a Video in HEVC Format with OpenCVSharp

Similarly, if you want to write a video in HEVC format, you can use VideoWriter with a codec like cv::VideoWriter::fourcc() for HEVC.

Example of writing a HEVC encoded video:

using OpenCvSharp;

class Program
{
    static void Main(string[] args)
    {
        // Open a VideoCapture object to read video frames
        var capture = new VideoCapture("input_video.mp4");
        if (!capture.IsOpened())
        {
            Console.WriteLine("Error: Could not open the video.");
            return;
        }

        int fourcc = VideoWriter.FourCC('H', '2', '6', '5');  // H.265 codec (HEVC)
        var writer = new VideoWriter("output_video.hevc", fourcc, capture.Fps, new OpenCvSharp.Size(capture.FrameWidth, capture.FrameHeight));

        Mat frame = new Mat();
        while (true)
[  **`[Read more >>>>](https://tinyurl.com/58xefyu5)
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