Frequently Asked Questions

For more background information, you should read this FAQ in conjunction with the others FAQs at minidisc.org (especially the NetMD FAQ and Audio FAQ) and the Open/NMD web pages.

  1. Why have there been no updates to Xmd for at least 10 minutes?
  2. I downloaded Xmd 0.1 and it always crashes on startup. Why?
  3. I'm considering purchasing a Net MD minidisc unit. Should I?
  4. When will Xmd be able to download audio data from my Mac to my minidisc by USB?
  5. When will Xmd be able to upload audio data from my minidisc to my Mac via USB?
  6. When will Xmd be able to download audio data from my Mac to my minidisc using an analogue or SP/DIF connection?
  7. When will Xmd be able to upload audio data from my minidisc to my Mac using an analogue or SP/DIF connection?
  8. When will there be an iTunes plugin?
  9. Can I use Xmd split and join tracks on a minidisc?
  10. What about CBBD support for titling discs?
  11. How do I run the omd command line program?
  12. Can I backup my data files to minidiscs using this software?
  13. Who's this "we" you keep referring to?
  14. What can I do to help?
  15. Why is there no mailing list to announce updates?

Why have there been no updates to Xmd for at least 10 minutes?
(This answer updated 29 December 2002)

I have been kept really busy at my day job the last few weeks and so have been unable to devote much time to Xmd. However I am now on holiday for a week and plan to devote some time to this project. There should be a new version released within a week... Not much new functionality, just tidying up user interface issues and a few bugs from version 0.1


I downloaded Xmd 0.1 and it always crashes on startup. Why?

Ah.

There was a howler of a bug slipped through... If the disc in your player is untitled, then Xmd 0.1 will crash on startup. Rest assured, I fired my QA department over this one.

This bug doesn't affect omd, the command line program, and it's fixed in the CVS versions (and in version 0.2 which will be released shortly


I'm considering purchasing a Net MD minidisc unit. Should I?

I'm not going to answer that, but I'd suggest you review the questions here about uploading and downloading audio, realise that that is not going to happen tomorrow and possibly never, then make your own mind up.


When will Xmd be able to download audio data from my Mac to my minidisc by USB?

Possibly never.

Firstly, in their wisdom, Sony have chosen to encrypt all audio data that is passed across the USB to the minidisc unit. No doubt they feel this will help in the fight against music piracy. Personally I am not convinced that this will do anything but turn people against the minidisc format. People who want to pirate music will stick to MP3 players (or iPods), professionals and other people who want the quality of ATRAC reproduction will just become frustrated that this functionality is unavailable/obfuscated

Secondly, for LP2 and LP4 (ie MDLP) tracks, the audio data is sent to the minidisc unit in ATRAC format. There are no known open source implementations of an ATRAC CODEC, nor are detailed specifications in the public domain, making it almost impossible to implement such a CODEC from scratch.

So, it may never be possible to download LP2 or LP4 data. There is some indication that SP data is sent to the minidisc as raw, PCM audio... So it may be possible to download SP audio if we can discover a way around the encryption problem. Naturally this will be slower than downloading LP2 or LP4 and you will be able to fit less on each disc.

Verdict: There's maybe a 50% chance that downloading audio via USB will be possible at some point, but it is likely to take many months of effort before the problems are solved.


When will Xmd be able to upload audio data from my minidisc to my Mac via USB?

Probably never.

Right now, we don't even know if this can be done. There are two possibilities:-

1) To aid their noble fight against the horrors of audio piracy, Sony have not even included this functionality in the firmware of their minidisc units. Obviously if this is the case, then there's no way any Mac (or PC) software is going to be able to upload audio from a minidisc.

2) Sony have included this functionality in their minidisc unit firmware but have chosen not to provide any way to access it from their PC software (possibly waiting until market conditions change). In this case there's a glimmer of hope, but nothing is going to be possible unless Sony provide some software to access this functionality that can then be analysed, or someone stumbles across it by sheer dumb luck. Even then, odds are it'll be subject to the encryption and ATRAC issues mentioned above.


When will Xmd be able to download audio data from my Mac to my minidisc using an analogue or SP/DIF connection?

Right now, we know how to set a Net MD minidisc into play, fast forward, rewind and pause mode. What we don't know is how to set it into record mode (recording from its line in or SP/DIF connection. Until then, this is not going to be possible

I have an open offer to buy dinner for anyone who discovers the USB commands to put a minidisc unit into record mode


When will Xmd be able to upload audio data from my minidisc to my Mac using an analogue or SP/DIF connection?

I plan to do this some time in the first quarter of 2003, probably not before February.

You will need to connect the Line Out socket (or SP/DIF Out if you have one, eg on a hifi deck rather than a portable) to a suitable port on your Mac. Xmd will then automate the process of uploading tracks or parts of tracks to AIFF files on your Mac.

If you have SP/DIF, then the fidelity of the uploaded file should be as good as if you had uploaded the ATRAC data via USB and decoded it locally. If you use analogue then there will some degradation... How much degradation depends on the quality of your minidisc player and the quality of the sound card on your Mac.


When will there be an iTunes plugin?

This is relatively low on my list of priorities... If we figure out how to implement download functionality, then this will become a higher priority


Can I use Xmd split and join tracks on a minidisc?

Basically the same answer as question 4 I'm afraid --- We don't know the USB commands make a minidisc player split or join tracks (or even if such commands exist)


What about CBBD support for titling discs?

Also planned for Q1 2003, but it's not as easy as it might appear. Minidiscs store tracks in slightly different way from CDs. They use sectors rather than frames, and there are a different number of sectors per second than frames per second. CDs use 74 frames/second, I think minidiscs use 84 sectors per second, but if anyone has different information I'd like to know.

Why does that matter? CDDB works out the 'id' for a CD as a function of all the track times on the CD... To calculate the same ID from a minidisc relies on converting from sectors to frames accurately.


How do I run the omd command line program?

(Beginners version) Copy the file "omd" from the Xmd disk image to your home directory. Open a new window in Terminal.app and type "./omd"

(For more advanced users) Copy the file "omd" to a directory that's on your PATH.

However, if you don't know how to run command line executables, what you really need to do is read a tutorial on Terminal.app and Unix shells. I don't really have time to evaluate tutorials to pick an appropriate one for you, but here's two I found via Google that look reasonably comprehensive:-


Can I backup my data files to minidiscs using this software?

No.

However, this strikes me as a cool idea (it was suggested by Dan ... if I ever manage to implement USB download and upload then I'll look into this... The plan would be to use a similar trick to that used by MDLP tracks to make them play as silence on non-MDLP players, then use the rest of each sector to store raw data.

Don't hold your breathe though.


Who's this "we" you keep referring to?

All the coding (and bugs) in Xmd (and omd and libomd) are my own work, however the effort involved in figuring out how the NetMD USB protocols work has very much been a collaborative effort with the other people working under the umbrella of the Open/NMD project.


What can I do to help?
Why is there no mailing list to announce updates?

Because I've been lame and my servers are in "a state of flux". It'll happen soon though, honest.


Please Mail me about any errors or omissions in this list:
Pete Bentley