Nick
Mainsbridge

# Exporting to CD

## Table of Contents

A Table of Contents is a description of the data stored on a medium. In the case of audio Cds, the TOC comes in the form of PQ data which is intermingled with the audio data whaen the CD is burnt. Because PQ data isn't part of 'normal' audio file formats such as wav or aiff, this information must be stored in a separate file on your computer (a CUE or TOC file) ready for use by your CD burning software which will combine the two.

At the moment, Ardour can export TOC and CUE files containing the red-book related fields Track, Index, ISRC, SCMS and Preemphasis. The CD-TEXT fields TITLE, COMPOSER, PERFORMER and disc title are also supported.

Range markers in Ardour can be 'promoted' to become CD tracks in the locations window. Marks (point markers) can be promoted to be CD Indexes in the same window. All TOC/CUE export operations hinge on this.

Assuming you have several songs on your timeline laid out so that their spacing and level is 'correct' as you hear it, you should then set ranges that represent the start and end points of each track, These will become the start and end points on your CD. The start times are all rounded down to the previous CD frame (Of which there are 75/second) on export, so if you want to hear the exact point that your CD player will start from, select 'CD frames' as your snap setting while you do this. If you want track indexes (nobody does, but they're there), set a location marker for each desired index.

The locations dialog is useful here, as you can just 'go' to a point to audition the exact position of a marker/range.

## Pregap

A word about pregap:

A 'normal' redbook CD should have a blank (digital black) space of 2 seconds before the first modulation called the pregap. Ideally, your first song will have been placed at 2 seconds when you began, but you can always drag the whole collection of songs to the right position fairly easily at this point.

Also, note that this 2 second rule can be fun to break. You can make the pregap as long as you like.. even hide whole songs in there. The player will still play track one when the disc is inserted. Only those listeners with the urge to rewind beyond the beginning will find your hidden song/dog bark. Also keep in mind that there is a pregap for each song. It starts where the previous song ends. In other words, if you leave a gap in the ranges between songs 2 & 3, that gap will only play for those listening through the entire CD. Anyone skipping directly to 3 will miss your secret 'long' intro.

After setting a non-overlapping range for each track (overlapping CD tracks are removed on export, from left to right, as are indexes that aren't inside a track), open the locations window and make your ranges into track markers by clicking the CD button. Fill in whatever information you feel is necessary in the boxes below. Unused fields will be ignored as far as the exported TOC/CUE file is concerned.

CD-TEXT track titles are taken from the range's name. The CD-TEXT title of the CD is taken from the session name (i should have told you that first, right?).

Pre-emphasis is there for those strange types that use it (they also use track indexes). You almost certainly don't want pre-emphasis. A valid ISRC is all capitals, 12 characters.

## Cue Files

Cue files have no notion of 'the end'. Its a drag. They think the end of the file is the end of the last track. If you want to use CUE files, you have to make sure that the session end marker is snapped to CD frames (before you export, of course), or else use the -pad option when you burn.

## Export The Session

Now export the session to a file (16bit 44.1kHz for CD), selecting your preferred cuefile type (TOC or CUE). The TOC/CUE file is written to the same directory as your audio file, and has the same name, only with '.toc' or '.cue' appended. Usually you will only be selecting the two master outputs to export, with output 1 always being 'left'. The export is post fader and panner. Don't assume that the sound will be identical after you have truncated/dithered to 16 bits. It can be worthwhile to experiment with different dither settings when making your export.

To check out the details without burning

    cdrdao show-toc blah.wav.toc

to correct a problem, make your changes, then use the 'export toc file only' option. If you have to change the session end marker, you'll have to re-export your audio file.

To burn

    cdrdao write /home/britney/globalsmash.wav.toc

One last thing:

If you don't make any CD Track ranges and export a TOC/CUE file, the entire session is treated as one track with no pregap. Indexes, if present, will be honoured.

## FAQ

Why no DDP? ( http://www.dcainc.com/products/ddp/ )

A: DCA have been kind enough to get in touch. Hopefully they will allow a GPL implementaton soon.

## What about catalog numbers for the CD?

A: coming eventually.. we need a tab for session-wide variables like these. where to put it? in the export dialog or the options menu?