带VideoCore VCSimpleSession的开关滤波器

Question

在VCSimpleSession上有一个VCFilter类型的filter属性

typedef NS_ENUM(NSInteger, VCFilter) {
    VCFilterNormal,
    VCFilterGray,
    VCFilterInvertColors,
    VCFilterSepia,
    VCFilterFisheye,
    VCFilterGlow
};

这些过滤器的实现在哪里？我该怎么用呢？

Answer 1

每个过滤器都驻留在过滤器/基本目录中的自己的文件中，并在运行时使用FilterFactory.cpp添加。

FilterFactory::FilterFactory() {
    {
        filters::BasicVideoFilterBGRA b;
        filters::GrayscaleVideoFilter g;
        filters::InvertColorsVideoFilter i;
        filters::SepiaVideoFilter s;
        filters::FisheyeVideoFilter f;
        filters::GlowVideoFilter gl;
    }
}

可以使用setFilter:方法设置过滤器。样本应用程序使用如下所示的UIButton遍历所有过滤器：

- (IBAction)btnFilterTouch:(id)sender {
    switch (_session.filter) {
        case VCFilterNormal:
            [_session setFilter:VCFilterGray];
            break;
        case VCFilterGray:
            [_session setFilter:VCFilterInvertColors];
            break;
        case VCFilterInvertColors:
            [_session setFilter:VCFilterSepia];
            break;
        case VCFilterSepia:
            [_session setFilter:VCFilterFisheye];
            break;
        case VCFilterFisheye:
            [_session setFilter:VCFilterGlow];
            break;
        case VCFilterGlow:
            [_session setFilter:VCFilterNormal];
            break;
        default:
            break;
    }
}