Function blosc2_schunk_frame_len 

pub unsafe extern "C" fn blosc2_schunk_frame_len(
    schunk: *mut blosc2_schunk,
) -> i64

@brief Get the length (in bytes) of the internal frame of the super-chunk.

@param schunk The super-chunk.

@return The length (in bytes) of the internal frame. If there is not an internal frame, an estimate of the length is provided.