ogg dev - Jan 2008 - Ogg/Kate preliminary documentation

Thanks for the feedback,
> I have looked into the patch.  It doesn't take into consideration
> neither Skeleton, which is used now in pretty much everything encoded
> in Ogg (except for single stream Vorbis and Speex files), nor the file
> extension for Theora, which is now .ogv.
To be honest, I just added Theora because I needed a simple way to
multiplex streams. Also, it'd likely take a rewrite of oggmerge to make it
usable for multiplexed streams, I think it assumes a single logical stream
per physical stream, though I didn't have an in-depth look at this issue.

I did see references to Skeleton, I'll have a look at it. I didn't
realize it was
used widely - I've certainly not seen anything with it in it (though I
don't
tend to download many Ogg streams, I encode test ones myself :)).

As for .ogv for Theora, do you mean Theora-in-ogg, or raw Theora ?
If Theora-in-ogg, then what about Theora multiplexed with other stream
types, like Vorbis, since a lot of videos will have sound embedded ?
> * don't bother with non-UTF8
Yes, I was going to leave it as is while keeping the header field there,
just in case. I do know, however, that people in eastern countries tend
to dislike utf-8 for the size it takes for their language, as it's been,
er...
/optimized/ for the latin alphabet. I am also not clear if every code point
can be coded in utf-8, I'll have to dig that up.
> * I agree that CMML is complex for something as simple as karaoke, but
> I am of the opinion that the more formats doing the same thing, the
> worse it will be for their adoption rate.  Developers just won't
Yes, this is a fair point, but then you have Vorbis, Speex, and FLAC,
each with its own particularities. Yes, Vorbis would probably yield bad
sound at the low bitrates Speex works at, etc, this is just an example.
> bother to support everything out there.  Some may support CMML, some
> may support Kate, some may support none.  Then we have the users not
> knowing which format to choose for lyrics/subtitles.  I think that
> perhaps it would be better to join efforts on an unique project.
I understand where you're coming from.

Thank you for your comments.

On 1/16/08, ogg.k.ogg.k@googlemail.com <ogg.k.ogg.k@googlemail.com>
wrote:
> Also, it'd likely take a rewrite of oggmerge to make it
> usable for multiplexed streams, I think it assumes a single logical stream
> per physical stream, though I didn't have an in-depth look at this
issue.
You are likely correct.
> I did see references to Skeleton, I'll have a look at it. I didn't
> realize it was used widely
It's not widely used currently.  The idea is to make that happen.
> As for .ogv for Theora, do you mean Theora-in-ogg, or raw Theora ?
> If Theora-in-ogg, then what about Theora multiplexed with other stream
> types, like Vorbis, since a lot of videos will have sound embedded ?
.ogv is the file extension for video on Ogg.  That is usually Theora,
but even OggMNG is supposed to use it.  And of course this also counts
if the file has multiplexed audio.  For instance, the basic media file
Theora + Vorbis + Kate/CMML (+Skeleton) would use .ogv.  People give
too much meaning to file extensions and we have to rely on that and
give them what they want, which is a way to distinguish  music from
video right from the file extension.
> I do know, however, that people in eastern countries tend
> to dislike utf-8 for the size it takes for their language, as it's
been,
> /optimized/ for the latin alphabet. I am also not clear if every code point
> can be coded in utf-8, I'll have to dig that up.
As far as I know, only the Japanese dislike UTF-8, and that's related
to how their language's characters were ordered in the Unicode table
(rather randomly).  UTF-8 is really the only sane way to support all
world's languages.  UTF-16 is considered by many to be overkill and no
better solution has ever been made.
> Yes, this is a fair point, but then you have Vorbis, Speex, and FLAC,
> each with its own particularities.
It's not really the same thing.  Each of those formats serves a niche.
 Roughly: Vorbis for lossy music, Speex for VoIP, and FLAC for
archival.

CMML does of course other things besides subtitles.  Subtitle support
was pretty much just added recently.  Kate however does not seem to
offer more than CMML in the lyrics/subtitles department, besides
perhaps the concept of converting other subtitles formats (ASS, SRT,
etc) to Kate which is a tool concept, not a format concept.  So CMML
and Kate end up both serving the same niche.

This does not mean Kate development should stop.  It just means that
if you are not willing to join efforts with the other developers we
will end up with two (let's not count Writ) different formats for the
same niche.  And then we have to tell people which of them should be
the default format for subtitles and lyrics, which means one format
will lose in favor of another, frustrating its developer(s).  I don't
think anyone wants that.

-Ivo

> > I did see references to Skeleton, I'll have a look at it. I
didn't
> > realize it was used widely
>
> It's not widely used currently.  The idea is to make that happen.
Oh, I get you now.
> CMML does of course other things besides subtitles.  Subtitle support
> was pretty much just added recently.  Kate however does not seem to
> offer more than CMML in the lyrics/subtitles department, besides
This is true, as the design of XML makes it malleable to custom semantics:
you can embed anything in an XML tree.
> perhaps the concept of converting other subtitles formats (ASS, SRT,
Which I have working in MPlayer now (from the 12 formats they support).
But this is, as you say, moot since it'd be as easy to create CMML
representations of these.
> This does not mean Kate development should stop.  It just means that
> if you are not willing to join efforts with the other developers we
> will end up with two (let's not count Writ) different formats for the
> same niche.  And then we have to tell people which of them should be
> the default format for subtitles and lyrics, which means one format
> will lose in favor of another, frustrating its developer(s).  I don't
> think anyone wants that.
I totally understand. I like doing this, so I will certainly not stop, but I do
see the possible counterproductive effect (which was quite apparent from
what I've seen on the web in discussions when I was looking at what was
there).
In parallel, I'll look more into CMML. However, without wanting to sound
overly dismissive, I've seen this name mentionned a few times in several
discussions over the years when text-in-ogg was mentionned, and we're
still there. Again, that's just from Google searches, so I may be missing a
lot, so please keep that in mind.

Thanks again for your feedback.