You can also write track-at-once and not finalize (it’s apparently not quite the same thing as multi-session. Again, though, not all standalone audio CD players support it.
Right, most software will ask you if you want to finalize the CD. if you check “Yes” then it will prevent you from adding to it later.
If you check “No” then you will be able to add to it later, but you may or may not be able to access the data stored on it until you do finalize it. (You will, likely, be able to access the partial non-finalized data from a computer, but not a CD player.)
A question on finalizing or authoring;
Why can’t a second session be added along with a new table of contents?
In my mind, you could add data to the finalized CD then make a new table of contents that tells the player to skip the first table of contents or treat it like an empty track. Or is that maybe what some of the posters above have done?
With audio CDs, you have the option of track-at-once or session-at-once, in addition to the option to finalize or not - I think the table of contents is written differently in either case and I believe that for audio CDs, multiple sessions are not part of the standard, whereas multiple tracks (even if recorded at different times) are, once finalized.
I believe in the case of multisession data CDs, a complete new table of contents is written for each session - with the old one simply becoming redundant, which is why it’s less efficient in terms of space usage.
It’s also worth mentioning at this point that the .cda files you may see appearing to exist on an audio CD are not real files - they’re a fiction created on the fly by Windows.
That’s possible if it’s built into the spec. But, I’m pretty sure that the original CD spec doesn’t tell you to look for an extra table of contents, or where to look for one, so as soon as one TOC is written, that’s the authoritative one.
Now, there are plenty of ways that could be solved (automatically look for another TOC past the end of the last track, include a “Next TOC” pointer in the first TOC, etc.). But if the exact solution isn’t specified, then stand-alone players won’t be able to use it. Best case, they just fail to find the new TOC. Worst case, they decide that the disk doesn’t conform to their standard, and refuse to play entirely.
Not the clearest post I’ve ever written. If I understand correctly, when you burn but don’t finalize, it becomes a data disc of sorts that the computer can read but a regular CD player can’t read. Once you finalize it, you can play it in your car etc. but there’s no more adding anything to it.
@mangetout: maybe the nomenclature differs from program to program. In realplayer, I think “disc at once” implies that the laser doesn’t turn off at all while burning. IIRC it eliminates the 2 or 3 second gap between songs. That leaves a little extra room on the disc of course but mainly I think it burns it faster.
If you want to know why audio CD players won’t play past the first session, cough up $50,000 and buy a copy of the “Red Book” spec: Compact Disc Digital Audio - Wikipedia
Those are used by pirates.