Function color_convert_ycbcr

fn color_convert_ycbcr(
    mcu_block: &[&[i16]; 4],
    width: usize,
    padded_width: usize,
    output_colorspace: ColorSpace,
    color_convert_16: fn(&[i16; 16], &[i16; 16], &[i16; 16], &mut [u8], &mut usize),
    output: &mut [u8],
)

Do color-conversion for interleaved MCU