[Cellar] ATRAC1 codec ID for Matroska

[Sir68k <[e-mail]>]

Dear Matroska team,



I'm part of a reverse engineering team for MiniDisc players, home at
https://www.minidisc.wiki/. Recently we've been modifying and patching
MiniDisc player firmware to allow dumping raw ATRAC1 audio data from
MiniDiscs. This is both for archival purposes and to improve the useability
of these devices for use in this 'modern' era.



There are currently no decent container formats for ATRAC1. The format that
is being used is 'aea', an arbitrary format from some legacy software with
no decent specification. It's supported by an open-source ATRAC1
encoder/decoder and FFMPEG, but is not without its issues. VLC regularly
misidentifies the container due to ambiguities in its header magic.



As RAW ATRAC1 isn't common but may become (slightly) more common due to the
ripping software that we have been creating, we would like to start using a
decent container format. Matroska already has support for ATRAC3 as a
format (A_REAL/ATRC), and as such, we would like to request a new codec ID
for ATRAC1 as well.



We are unsure as to what the new ID should be. As ATRAC is a category of
codecs, we were thinking of A_ATRAC/AT1. This of course might create
confusion for ATRAC3, which is currently under A_REAL/ATRC but would be
expected to be at A_ATRAC/AT3. Since ATRAC3Plus and ATRAC9 do exist, I
believe this ID pattern makes the most sense in terms of future
extensibility.



We hope that you might have some insights into this as well; if getting a
standardized ID for ATRAC1 is possible and if so, what the best ID
structure would be.



Kind regards,

Sir68k