函数 av_display_matrix_flip 

pub unsafe extern "C" fn av_display_matrix_flip(
    matrix: *mut i32,
    hflip: c_int,
    vflip: c_int,
)

Flip the input matrix horizontally and/or vertically.

@param[in,out] matrix a transformation matrix @param hflip whether the matrix should be flipped horizontally @param vflip whether the matrix should be flipped vertically