Standard 80/74 min (non-Hi-MD) Minidisc title character limitations

[freddyjollo]

I have the Philip Pullman "His Dark Materials" audio books  on cds so decided to put them on LP4 md. The cds consist of titled  short sections ( often 2-3 minutes long) . I found after a time though the tracks  were stored the titles were not but left blank. So it seems there is a limit to the amount of  text in the titles that can be stored . I over came this by converting the LP4 md to a HiMd

[BearBoy]

How many tracks were you able to title before you started encountering blanks?

[Richard]

Yes, there is a limit to the total number of characters per disc (see below from the NH900 manual). It's much lower on standard MD's vs. Hi-MD formatted discs. 

[kgallen]

MD has a track limit (I think 255) and a total character limit for titles (and with I think a minimum of 7 per track). The titles limit should be pretty hard to hit. I’ve hit it once with an audio test disc that had over 100 very short tracks but very long descriptive titles. I’ll look up the spec - probably in that MD primer doc on minidisc.org

 

ETA - beaten to it!

[Richard]

3 minutes ago, kgallen said:

ETA - beaten to it!

great minds think alike! (and at the same time it seems) 😁

[BearBoy]

Good work 🙂

I'd checked the manual for one of my decks and found the 255 track limit information but had missed the 1700 character limit (it was a few pages further on - and not in the section about naming tracks) 🤦‍♂️

[BearBoy]

55 minutes ago, kgallen said:

MD has a track limit (I think 255) and a total character limit for titles (and with I think a minimum of 7 per track).

Not sure if I've misunderstood what you're saying here Kevin but I've just done a test and was able to name tracks with a single character: A, B, C etc

[kgallen]

16 minutes ago, BearBoy said:

Not sure if I've misunderstood what you're saying here Kevin but I've just done a test and was able to name tracks with a single character: A, B, C etc

Yea sorry I wasn’t clear. What I mean is 7 bytes of storage are taken as a minimum so titles of 1 thru 6 characters still take a 7 byte block on disc. Agree you can have 1 character titles. 
 

I could have made that up!

[BearBoy]

Ah, I see what you mean. I think 🤔

So if I used a single character title (e.g. A), it would still take up 7 of the 1700 available characters? Or am I still being dim?

[kgallen]

9 minutes ago, BearBoy said:

Ah, I see what you mean. I think 🤔

So if I used a single character title (e.g. A), it would still take up 7 of the 1700 available characters? Or am I still being dim?

Yes that’s correct. Indeed and 8 character title takes 14 bytes. It’s modulo 7 as title blocks are 7 bytes long.

[kgallen]

From the MD FAQ:
 

The titling capacity in the Minidisc UTOC is as follows:

1. There are 255 name blocks available, each one able to hold 7 characters, so the absolute maximum for all tracks combined is 255*7=1785 characters.
2. The number of name blocks used by a track is: (title characters+6)/7 (rounding quotient down to nearest integer).
3. The disc title is handled just like any other track title (the disc title is placed on track #0, which is actually the MD's free list). 

So, each track that has a title takes at least one of these blocks. This means that if you have 255 tracks, all must have titles of 7 characters or fewer, or some tracks must go without titles. It also means that MD does not have the capacity for a disc title plus 255 track titles, one track (or the disc) would have to have an empty title. In addition to these limits, certain units may not display or allow entry of long titles, for example Sony's MDX-U1 car player only displays the first 32 characters of a title.

[BearBoy]

Got it. Thanks Kevin 🙂

All somewhat hypothetical for me tbh as I only use MiniDisc to record music (at an average of four to four-and-a-half minutes per song?) and have never really used LP4. So I'm probably looking at a maximum of 35-40 tracks per disc at LP2 to use up those 1700 characters (average of 42 available per track if I had 40 tracks). I don't think most song titles are that long.

Obviously a different scenario if you're using MDs in the manner Freddyjollo is or for things like sound effects etc.

 

Still, it's good to know these things 😀

[kgallen]

Exactly. Needs to be fairly extreme usage to hit the limit. Sony of course balanced space for metadata versus payload (music) data in the MD spec. Not devised by dummies! Clever chaps them Sony engineers!

[freddyjollo]

6 hours ago, BearBoy said:

How many tracks were you able to title before you started encountering blanks?

about 40 with text like this "10-Meat For The Prisoners, Them As 'ave Teeth" ie quite long titles  ( 6 cds each with 18 or so short tracks).I was quite pleased with my self dragging the folders in Sonic stage over to the copy window and let it get on with it and came back to see see all the blank titles . The titles are in the cd

[BearBoy]

Quite long titles then 😉

If I've counted correctly that's 45 characters, which will actually consume 49 of the 1700 available. I can see how you'd run out of characters if the 40 or so tracks all have similarly lengthy titles.

Glad you found a solution in HiMD though.