函数 av_packet_make_refcounted 

pub unsafe extern "C" fn av_packet_make_refcounted(
    pkt: *mut AVPacket,
) -> c_int

Ensure the data described by a given packet is reference counted.

@note This function does not ensure that the reference will be writable. Use av_packet_make_writable instead for that purpose.

@see av_packet_ref @see av_packet_make_writable

@param pkt packet whose data should be made reference counted.

@return 0 on success, a negative AVERROR on error. On failure, the packet is unchanged.