[Vorbis-dev] Vorbis, ambisonics and 'Vorbis Tools'

[Conrad Parker]

2008/11/2 Oliver Thuns <oli+243897 at ml0815.streaps.org>:
> On Sun, Nov 2, 2008 at 11:20 AM, Tuomo Latto <djv at iki.fi> wrote:
>> e deleflie wrote:
>>> This is incomplete... but the idea here is that since ambisonic
>>> content can take on all sorts of channel configurations, it would be
>>> beneficial to have a human readable  description of what
>>> orders/components are involved (rather than opening it in an audio
>>> editor, which may or may not be capable of displaying the header
>>> info).
>>
>> Out of curiosity, what is the purpose of such description
>> if you don't have any tools capable of handling said files?
>>
>> That said, it doesn't sound inconceiveable to modify ogginfo
>> to decode and display this information for ambisonics files.

we're simply talking about a VorbisComment tag here. ogginfo and
ogg123 will already display it; vorbis-tools does not need
modification to support this.

> I agree with Tuomo. Do users really look into the Comment fields?
> There always hidden in some menu. It's better to name the file
> accordingly or put the information somewhere, where it's more obvious.
> No player/decoder should rely on the information in the
> AMBISONICFORMAT tag. So it's useless for the machine and doesn't get
> recognized by the user. Also a file without an AMBISONICFORMAT tag
> could still be an Ambisonics file.

There was no suggestion that a player or decoder must rely on that
tag. It was suggested that this optional summary information might be
useful for users, so your point about not being machine readable is
not relevant.

The information is useful (according to the draft), so the next step
is to identify tools (file managers, editors, players) for which it
makes sense to more prominently display the AMBISONICFORMAT tag.
Modification to do that should be straightforward as all Vorbis
libraries make this information readily available.

Various current VorbisComment proposals are in development at
http://wiki.xiph.org/VorbisComment.

cheers,

Conrad.