Re: [linux-minidisc] Minidisc - Upload and conversion of atrac3plus [fwd: jan.olav@ramson.org]

["Jan Olav Stangeland" <minidisc@ramson.org>]

On Tue, March 16, 2010 18:53, Adrian Glaubitz wrote:
> Hi Jan,
>
>
>>
>> Hello,
>>
>>
>> thank you very much for your work to create an open alternative for
>> using MiniDiscs. I have many recordings that I am eager to transfer and
>> decode -> encode, and have a few question that I could not find in the
>> faq.
>>
>
> Thanks for using our software :).
>
>
>> I have the following devices:
>>
>>
>> MZ-RH1
>> MZ-R50
>> MZ-R55
>>
>>
>
> The MZ-RH1 is the only one of the aforementioned Walkman which can
> actually be connected to a PC over USB, thus it's the only one which can be
> used with our software. However, tracks recorded with the MZ-R50 and 55
> can easily transfered to the PC with our software. I will explain later
> on.
>
>> 1.
>> MZ-RH1 (Hi-LP/Hi-SP): Uploading works fine and produces .oma files.
>>
>
> Ok, this means that the tracks are not protected. This means they were
> recorded with the MZ-RH1 and are thus encrypted with a constant key only.
> We know this key and we can therefore decrypt these tracks. If
> the tracks were recorded with another HiMD device, the encryption key would
> be unknown and thus we are not (yet) able to decrypt the tracks because
> our software does not yet support tracks recorded with what we call
> "strong" encryption.
>
>
>> However, when I import these files into SonicStage for conversion to
>> wav, SonicStage states that some of the files are protected and refuses
>> to convert them.
>
> This is strange. These were recorded in ATRAC3+, right? SonicStage
> should be able to read them. The only scenario I could think of is that our
> software somehow messed with the file format so that the .oma-files appear
> broken to SonicStage.
>


Yes, they were recorded in ATRAC3+


>> In other words, some files import and convert just fine,
>> while others get imported (and can be played), but cannot be converted
>> (making them essentially useless). I have so far not been able to
>> identify any differences that would explain why some files are marked as
>> protected while others are not.
>>
>
> Hmm, I don't see a reason why SonicStage would refuse to convert
> them. Were all of these tracks recorded with the MZ-RH1 recorder?


Yes. Would a sample be helpful?

In SonicStage:
Right click - Properties - Rights Info/Additional Info tab

File that cannot be converted:
No. of times played: 2times
No. of times transferred: 0times
Remaining ATRAC CD transfer count: 0times
Remaining audio CD transfer count: 0times

File that can be converted
Playback restrictions: None
No. of times played: 6times
No. of times transferred: 0times
Remaining transfer count: Unlimited
Remaining ATRAC CD transfer count: Unlimited
Remaining audio CD transfer count: Unlimited

>
>> iii) Is there an atrac3plus decoder available for GNU/Linux (for tracks
>>  that are not encrypted).
>>
>
> No, there is no decoder yet! However, there are working decoders for
> ATRAC3 and ATRAC-SP (the original ATRAC-format, which your MZ-R
> recorders use for example). However, reverse-engineering of ATRAC3+ has
> already been initiated and the ffmpeg-guys who implemented ATRAC-SP for
> Linux (and other operating systems) are already looking
> to implement ATRAC3+ for ffmpeg and thus Linux. It's just a matter of time,
> ressources are very limited, unfortunately.
>
>> 2.
>> MZ-R50 and MZ-R55 (SP-Mono/SP-Stereo): Using lsmd.py all tracks lists as
>>  unprotected. Uploading with upload.py works fine and produces .aea
>> files. However, using FFmpeg (version SVN-r22323), only a few tracks are
>>  identified as atrac1 (most cannot be identified as such, even though
>> the format is the same, e.g. some SP-Mono tracks can be identified as
>> such, while others cannot): (...)
>> i) Do you know if this is a problem with ffmpeg?
>
> Ah, this is something which Benjamin Larsson should look into. He is
> the guy who developed this codec together with other guys and he should
> know best.
>
>> Please find four samples attached, SP-Mono and SP-Stereo recorded on
>> the MZ-R50 and MZ-R55, respectively.
>>
>
> Thanks, I think these will help best when debugging the problem. As I
> said, Benjamin will be the right guy to check (I hope he won't be upset now
> that I'm, blaiming him ;)).
>
>> 3)
>> I am interested in learning more about the MiniDisc and would be
>> grateful if I could have a user account for the wiki, enabling me to
>> read all of the contents.
>>
>
> No problem, I will send one to this email, is this ok?
>

Yes.

>
>> Once again, thank you for the great work done so far!
>>
>
> You're welcome. Thanks for using our software!
>
>
> PS: Please join the mailing list to stay tuned for updates.
>
>
> Adrian
>
>
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