Video Sharpening with OpenCV & FFmpeg 7

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

int main() {
    // 1. 使用 FFmpeg 后端打开视频流 (cv::CAP_FFMPEG)
    cv::VideoCapture cap("blurry_input.mp4", cv::CAP_FFMPEG);
    if (!cap.isOpened()) {
        std::cerr << "Error: Cannot open video file." << std::endl;
        return -1;
    }

    // 2. 获取原视频的参数 (宽高、帧率)
    int width = static_cast<int>(cap.get(cv::CAP_PROP_FRAME_WIDTH));
    int height = static_cast<int>(cap.get(cv::CAP_PROP_FRAME_HEIGHT));
    double fps = cap.get(cv::CAP_PROP_FPS);
    // 强制使用 H.264 编码器 (依赖 FFmpeg 的 libx264)
    int fourcc = cv::VideoWriter::fourcc('H','2','6','4');

    // 3. 初始化 VideoWriter，同样指定 FFmpeg 后端
    cv::VideoWriter writer("clear_output.mp4", cv::CAP_FFMPEG, fourcc, fps, cv::Size(width, height));

    // 4. 定义拉普拉斯锐化矩阵
    cv::Mat kernel = (cv::Mat_<float>(3, 3) <<
         0, -1,  0,
        -1,  5, -1,
         0, -1,  0);

    cv::Mat frame, sharpened_frame;
    int frame_count = 0;

    // 5. 循环读取每一帧，处理并写入
    while (cap.read(frame)) {
        cv::filter2D(frame, sharpened_frame, -1, kernel);
        writer.write(sharpened_frame);
        frame_count++;
        if (frame_count % 30 == 0) std::cout << "Processed " << frame_count << " frames..." << std::endl;
    }

    cap.release();
    writer.release();
    std::cout << "Success: Video sharpened and saved!" << std::endl;
    return 0;
}