Re: [linux-minidisc] implementing netmd support in the gui application

[Michael Karcher <Michael.Karcher@fu-berlin.de>]

On Fri, 2012-12-07 at 21:10 +0100, John Paul Adrian Glaubitz wrote:
> > I think Michael can give more information.
> 
> This isn't actually correct. We can transfer ATRAC files via NetMD
> likewise we can transfer WAV (PCM) files which are transcoded
> on-the-fly by the NetMD device into ATRAC-SP.
> 
> What we can't do is encode ATRAC files ourselves as there is no known
> ATRAC encoder outside SonicStage/SoundForge.

This is mostly true. There also is the ATRAC3 ACM codec pack by Sony,
which is an ATRAC3 (which means LP2/LP4) encoder integrated in the
ancient 32-bit Windows Multimedia system (which pre-dates DirectX /
DirectShow). Too bad that the ACM support in Wine is not really present,
which would otherwise be an elegant way to encode ATRAC3 in Linux.

> So, coming back to Maximo's question: Yes, you can transfer ATRAC
> files to the NetMD device and we can do it.
To be more precise: We are able to transfer ATRAC3 (this is ATRAC LP2
and ATRAC LP4) as-is to NetMD devices. There should be some support of
uploading ATRAC3 105kpbs (also known as LP3) too, which gets padded by
the NetMD unit, so it is stored as LP2 on the medium.

There is no support of transferring plain ATRAC (this is not ATRAC3),
also known as ATRAC SP from the PC to the NetMD unit, but, as Adrian
told you, you can create ATRAC SP tracks on NetMD units by sending raw
PCM data, which gets encoded to ATRAC SP.

There is no support for sending ATRAC3+ or ATRAC3 with bitrates
different from LP2, LP3 or LP4 to the NetMD unit.

> libnetmd supports ATRAC as well as PCM, but I am not 100% sure about
> the status quo. It might be that some sample rates are currently not
> supported, I have to look at the source code again.
libnetmd does support all formats mentioned above, but the tool netmdcli
does not.

> > >  And, if so, will be
> > >able to make trackmarks?I mean, I can do them in any track I record,
> > >but not in one I transfer using sonicstage, and I don't know if this
> > >is a limitation in hardware or just on sonicstage.
There are no trackmarks on the technical side of the MD world, but there
is gapless playback of different tracks. Instead of setting a mark, you
are splitting a track, so a new track begins at the mark.

Splitting tracks is not allowed for tracks that are subject to DRM, as
this would destroy the watermark used by the computer to identify a
track when you check it in (delete it from the MD and increase the
license counter on the computer). If the track was edited (split, merged
and so on), you can't check it in, as the watermark does no longer
match. So the intent of the prevention of setting "track marks" is not
to limit the user, but to protect the user from losing his playback
licenses.

> It will work with tracks transferred with libnetmd/QHiMDTransfer as we
> don't set the DRM flag.
libnetmd does send a "these tracks are not subject to DRM" command to
the NetMD unit, but not all units support this command. Older units mark
them as DRMed tracks even if this command has been sent (and been
rejected as invalid command). I don't know which units support getting
tracks from the computer without marking them as protected.

Best regards,
  Michael Karcher