Subject: [Cellar] Unused / obsolete sections in Matroska

From: Thomas Daede <[email-masked]>
Date: Sat, 16 Jul 2016 00:58:17 -0700

Reading draft-lhomme-cellar-matroska-00, it seems that there are many
sections that were never implemented, and could be removed from the
specification. It seems like an easy way to reduce the size of the 220
page spec :)

240. Beginning of file. This is already part of the EBML specification,
and in fact seems to violate it.

264. CodecID. The whole "to be supported" section can go.

264.4.1. Matroska script

264.4.2. DVD menu

269. USF subtitles

273. File access. This section seems to exist to complement 274. Live
Streaming, but doesn't really specify anything.

275-279. Menu specifications

- Thomas

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From: Steve Lhomme <[email-masked]>
Date: Sat, 16 Jul 2016 10:17:30 +0200

> specification. It seems like an easy way to reduce the size of the 220

I agree.

> and in fact seems to violate it.

Yes

> 264. CodecID. The whole "to be supported" section can go.

Yes

> 264.4.1. Matroska script

The implementation exists (in VLC and Haali's DirectShow filter) but
that could well be a different specification. It's not used for normal
playback/storage.

> 264.4.2. DVD menu

It's still a work in progress, never finalized. It can be a different
spec, one day.

> 269. USF subtitles

Less sure about that. The format is used in some files.

> 275-279. Menu specifications

It's like Matroska script and DVD menus. A work in progress partly
implemented. It can be a different spec and is not needed in the
main/base Matroska usage.

> - Thomas
>
> _______________________________________________
> Cellar mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/cellar

-- 
Steve Lhomme
Matroska association Chairman

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From: hubblec4 <[email-masked]>
Date: Sat, 16 Jul 2016 10:28:34 +0200

Hi all

> that could well be a different specification. It's not used for normal

Thats nice to know.  And I hope we can difine more usefull Martoska 
script actions.
A simple Matroska menu would a very nice feature.
> It's still a work in progress, never finalized. It can be a different

A very complex system and I have never seen a practice usage, but maybe 
one day it works.

> main/base Matroska usage.

+1

>> - Thomas

kind regards
Martin

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From: Nithin Mathew Kurien <[email-masked]>
Date: Sat, 16 Jul 2016 14:19:45 +0530

On Sat, Jul 16, 2016 at 1:58 PM, hubblec4 <[email-masked]> wrote:

> Thats nice to know.  And I hope we can difine more usefull Martoska script
> actions.

I second that. A menu would be good to have.

> A very complex system and I have never seen a practice usage, but maybe

The DVD menu has been fully implemented in open-source players like VLC,
Kodi and MPC-HC, and its documentation is available. I think it is probably
not very difficult to implement it in the Matroska format, since we already
have a template to work on.

Thanks,
Nithin

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From: Moritz Bunkus <[email-masked]>
Date: Sat, 16 Jul 2016 11:13:39 +0200

Hey,

I agree.

I agree.

> 275-279. Menu specifications

Matroska script is useful, but the question is whether this must be part
of the main spec. In an effort to to reduce the size of the main spec
several parts should probably be moved to their own spec document; this
is a candidate.

Another candidate for moving into its own document might be the whole
section about how codecs are mapped to Matroska (the section called
"CodecID").

> 269. USF subtitles

mkvmerge and mkvextract support USF in Matroska and have for a long
time. However, I don't know if there are people actually using the
format. I'd rather keep it, though.

I agree.

Kind regards,
mosu

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From: Thomas Daede <[email-masked]>
Date: Sat, 16 Jul 2016 05:41:41 -0700

> section about how codecs are mapped to Matroska (the section called

This is the pattern in other IETF WGs, for example RTP has many payloads
individually defined:

https://datatracker.ietf.org/wg/payload/documents/

Opus also had its mapping into Ogg in a separate document:

https://datatracker.ietf.org/doc/rfc7845/?include_text=1

- Thomas