HeifReader.java 文件源码

private static Bitmap convertYuv420ToBitmap(Image image) {
    RenderScript rs = mRenderScript;
    final int width = image.getWidth();
    final int height = image.getHeight();

    // prepare input Allocation for RenderScript
    Type.Builder inType = new Type.Builder(rs, Element.U8(rs)).setX(width).setY(height).setYuvFormat(ImageFormat.YV12);
    Allocation inAlloc = Allocation.createTyped(rs, inType.create(), Allocation.USAGE_SCRIPT);
    byte[] rawBuffer = new byte[inAlloc.getBytesSize()];
    int lumaSize = width * height;
    int chromaSize = (width / 2) * (height / 2);
    Image.Plane[] planes = image.getPlanes();
    planes[0].getBuffer().get(rawBuffer, 0, lumaSize);
    planes[1].getBuffer().get(rawBuffer, lumaSize, chromaSize);
    planes[2].getBuffer().get(rawBuffer, lumaSize + chromaSize, chromaSize);
    inAlloc.copyFromUnchecked(rawBuffer);

    // prepare output Allocation for RenderScript
    Bitmap bmp = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
    Allocation outAlloc = Allocation.createFromBitmap(rs, bmp, Allocation.MipmapControl.MIPMAP_NONE, Allocation.USAGE_SCRIPT | Allocation.USAGE_SHARED);

    // convert YUV to RGB colorspace
    ScriptC_yuv2rgb converter = new ScriptC_yuv2rgb(rs);
    converter.set_gYUV(inAlloc);
    converter.forEach_convert(outAlloc);
    outAlloc.copyTo(bmp);
    return bmp;
}