[NUT-devel] questions about "Language" info packets

Michael Niedermayer michaelni at gmx.at
Wed Feb 14 13:47:22 CET 2007


On Wed, Feb 14, 2007 at 09:32:48AM +0100, Clemens Ladisch wrote:
> Michael Niedermayer wrote:
> > On Tue, Feb 13, 2007 at 03:36:34PM -0500, Rich Felker wrote:
> > [...]
> > > > So ISO 3166 is out, too?
> > > 
> > > I'm against 2-letter codes. The number of languages is way too large
> > > for these codes to be remotely sufficient.
> > 
> > ISO 3166 is about country codes and about half of the codes from the 2
> > letter codespace seem to be used or reserved in some way ...
> But should three-letter country codes be allowed?

i dont know, but i would prefer if either 2 or 3 letter codes would be
used but not both ...

> In that case, how should the entire language string be formatted?
> Something like "lll-ccc" where both "lll" and "-ccc" are optional?

that is a good question, i also thought of lll-ccc when i was working on that
part of the spec
seems it was never explicitly writen in the spec though :(
"-ccc"  though seems invalid to me it rather should be
"unk-ccc" or "mul-ccc"

> > > >     For historical reasons, demuxers MUST treat "multi" like "mul" and
> > > >     "" (the empty string) like "und".
> > > 
> > > Historical reasons?? There are no such files, and this is a draft
> > > (albeit frozen) spec.
> Well, I interpreted "frozen" to mean that no incompatible changes could
> be made at all ...

well, "" will be interpreted as unknown anyway
based on the ignore unknown strings, "multi" would be incorrectly interpreted
as unknown but there is AFAIK no muxer which generates such files 
!if anyone knows of a muxer which does please say so!
and the other way around (old demxuer new muxer) is no problem as mul/unk
are part of the language codes so they theoretically must be supported

i certainly dont like changing a frozen spec but in this case it really seems
like the simplest, as there shouldnt be any adverse effects, we should of
course add a note in the spec about "multi"/"" but not make their support
mandatory IMHO

also note if anyone thinks this is unproffessional, ISO completely changed
the motion compensation specification in MPEG4 after the spec was a full
international standard IIRC ... they changed it to what their reference sw
did becasue many seem to have based their codecs on the reference sw instead
of the written spec ...

> > > I don't see any way that translating "multi" to
> > > "mul" and "" to "und" would improve functionality over just treating
> > > them as an unexpected value. If there's cruft in the spec that can be
> > > removed without really hurting anything, I'd like to remove it.
> > 
> > well then lets add a
> > "a muxer MUST ignore unknown language and country codes instead of treating
> > them as an error"
> Agreed.


Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

It is dangerous to be right in matters on which the established authorities
are wrong. -- Voltaire
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