[opus] libopusfile's memory management.

[Timothy B. Terriberry]

alpha thinktink wrote:
> Thanks.
>
> At the moment I'm not sharing any headers stuff as that is being purely
> internally handled by the playback thread (no need to share it across
> threads) and I've already implemented handlers for album art so, at the
> moment, I don't predict I'll need a copy function for anything else.
> Others might though for the new album art handler but other than me, no.

Well, that at least has a simple (if slightly inefficient) solution: 
call opus_picture_tag_parse() again.