Android: Sharpen Video via JavaCV (FFmpeg + OpenCV)

import org.bytedeco.javacv.FFmpegFrameGrabber
import org.bytedeco.javacv.FFmpegFrameRecorder
import org.bytedeco.javacv.OpenCVFrameConverter
import org.bytedeco.opencv.global.opencv_imgproc
import org.bytedeco.opencv.opencv_core.Mat
import org.bytedeco.opencv.opencv_core.CvType
import org.bytedeco.opencv.opencv_core.Size

fun processVideoSharpening(inputPath: String, outputPath: String) {
    // 1. 初始化 FFmpeg 视频拉取器
    val grabber = FFmpegFrameGrabber(inputPath)
    grabber.start()

    // 2. 初始化 FFmpeg 视频编码写入器 (保持原宽高)
    val recorder = FFmpegFrameRecorder(outputPath, grabber.imageWidth, grabber.imageHeight)
    recorder.frameRate = grabber.frameRate
    recorder.videoCodec = grabber.videoCodec // 沿用原编码格式
    recorder.videoBitrate = grabber.videoBitrate
    recorder.start()

    // 3. 初始化帧格式转换器 (FFmpeg Frame <-> OpenCV Mat)
    val converter = OpenCVFrameConverter.ToMat()

    // 4. 构建 3x3 拉普拉斯锐化矩阵
    val kernel = Mat(3, 3, CvType.CV_32F)
    val kernelData = floatArrayOf(
        0f, -1f,  0f,
       -1f,  5f, -1f,
        0f, -1f,  0f
    )
    // 获取指向矩阵数据的指针并填入数据
    kernel.createIndexer().put(*kernelData)

    // 5. 循环逐帧处理
    var frame = grabber.grabImage()
    val sharpenedMat = Mat()
    while (frame != null) {
        val mat = converter.convert(frame)
        // 调用 OpenCV filter2D 进行锐化
        opencv_imgproc.filter2D(mat, sharpenedMat, mat.depth(), kernel)
        // 将处理后的 Mat 转换回 Frame 并交由 FFmpeg 写入
        recorder.record(converter.convert(sharpenedMat))
        frame = grabber.grabImage()
    }

    // 6. 释放资源
    recorder.stop()
    recorder.release()
    grabber.stop()
    grabber.release()
    kernel.close()
    sharpenedMat.close()
}