Function heif_image_get_bayer_pattern 

pub unsafe extern "C" fn heif_image_get_bayer_pattern(
    arg1: *const heif_image,
    bayer_component_id: u32,
    out_patternPixels: *mut heif_bayer_pattern_pixel,
) -> heif_error

Get the Bayer / filter array pattern pixels. The caller must provide an array large enough for pattern_width * pattern_height entries (use heif_image_get_bayer_pattern_size() to query the dimensions first). Returns heif_error_Ok on success, or an error if no pattern is set.