encode timestamps

[qishuhua]

When I use CV: CUDACodec: VideoWriter encoding, video cannot be played in VLC, converted to ffmeg and displayed as follows " Timestamps are unset in a packet for stream 0. This is deprecated and will stop working in the future. Fix your code to set the timestamps properly"

version:opencv_contrib-4.8.0

[cudawarped]

Can you share the code you use for encoding? Specifically which codec and what is the file extension of the encoded video?

OpenCV 4.8.0 only supports raw output (not containers) so your file extension should be .h264 or .h265 which should play in vlc without issue.

If you want the encoded video to be stored in a container (.mp4) then you need to upgrade to the latest version of OpenCV (latest commits from the 4.x branches of the main and contrib repositories).

[qishuhua]

I want the encoded video to be stored in a container (.mp4),I will try again using the latest version of OpenCV.thank you for your answer

[qishuhua]

`void TestHWEncoder(const std::string& inputPath, const std::string& outputPath) {
try {
cv::VideoCapture videoReader(inputPath);
if (!videoReader.isOpened())
{
std::cerr << "Can't open input video file" << std::endl;
return;
}
int Width = videoReader.get(cv::CAP_PROP_FRAME_WIDTH);
int Height = videoReader.get(cv::CAP_PROP_FRAME_HEIGHT);
double fps = videoReader.get(cv::CAP_PROP_FPS);

    cv::Mat frame;
    cv::cuda::GpuMat GpuFrame;
    cv::cuda::Stream stream;

    cv::cudacodec::EncoderParams params;
    params.nvPreset = ENC_PRESET_P1;
    params.encodingProfile = ENC_H264_PROFILE_BASELINE;
    params.averageBitRate = 2000000;

    cv::Ptr<cv::cudacodec::VideoWriter>  d_writer = cv::cudacodec::createVideoWriter(outputPath, cv::Size(Width, Height), 
        cv::cudacodec::Codec::H264, fps, cv::cudacodec::ColorFormat::BGR, params,0, stream);

    for (;;)
    {
        if (!videoReader.read(frame))
        {
            std::cout << "Stop" << std::endl;
            break;
        }
        GpuFrame.upload(frame, stream);
        d_writer->write(GpuFrame);
    }
}
catch (const cv::Exception& e) {
    std::cerr << "OpenCV Exception: " << e.what() << std::endl;
}

}`
General configuration for OpenCV 4.12.0-dev =====================================
Version control: 4.11.0-160-gb5f5540e8a

Extra modules:
Location (extra): D:/github/opencv_contrib/modules
Version control (extra): 4.11.0-14-gce3c6681

Platform:
Timestamp: 2025-02-22T10:10:38Z
Host: Windows 10.0.26100 AMD64
CMake: 3.31.5
CMake generator: Visual Studio 16 2019
CMake build tool: C:/Program Files (x86)/Microsoft Visual Studio/2019/Community/MSBuild/Current/Bin/MSBuild.exe
MSVC: 1929
Configuration: Debug Release
Algorithm Hint: ALGO_HINT_ACCURATE

Still can't play

[cudawarped]

I just tried your MRE using the big_buck_bunny.h264 test file and it played in vlc without any issues. e.g.

TestHWEncoder(big_buck_bunny.h264, big_buck_bunny.mp4);

Are you writing to an mp4 container? What errors do you get in vlc?

Note: The writer also excepts host frames. i.e. You can use d_writer->write(frame);