Burn Baby Burn

Many Free Software disc-authoring tools are available, both command-line and graphical, and practically all of them can make valid audio CD-Rs. Most of these tools, like their proprietary equivalents, treat the audio tracks as if they were generic files, listing them in a window with track-length information. In contrast, GNOME CD Master (GNU/Linux) draws the audio data as a waveform, which, as you read earlier, is a digital representation of the real-life audio wave. This feature allows you to see at once if the audio data is too loud or too quiet, or inconsistent in level between tracks. Superficially, GNOME CD Master resembles an audio editor such as Audacity, but in fact there are only limited cut and paste features available. Instead, the program is designed to let you append or insert audio from .wav files into a sequence of data that is then burned to disc. GNOME CD Master is available for download from http://cdrdao.sourceforge.net/gcdmaster/ or ready-packaged in many GNU/Linux distributions. Ubuntu users can download it using the Add/Remove Applications tool, which adds an entry for the program to the Sound & Video menu.

The gcdmaster program is a front-end for cdrdao, the command-line tool for disc-at-once recording. Recording CDs this way, instead of track by track, gives you fine control over the gaps between tracks—or, alternatively, enables you to have track markers without any gaps. This feature is useful for dividing up a long recording without splitting it into individual files first. If you have to change track positions, it's a lot quicker to do it with markers than to go back to the source material and chop up .wav files again. The program also has some support for parallel burning to multiple drives, which could be very useful if you're thinking of going into mass production.


Some versions of Ubuntu, including Jaunty, have a bug that delays the start-up of GNOME CD Master by ten or more seconds. If you run gcdmaster in a terminal, you may see a message like this, over and over again:

Error trying to open /dev/sg0 exclusively (Permission denied)... retrying in 1 second.

On some computers, this bug prevents CDs from being written with this program, because GNOME CD Master runs but can't scan the burner hardware. If this is the case on your computer, you can use a different CD-burning program such as Brasero (GNU/Linux), which is installed on Ubuntu by default.

To get started with GNOME CD Master, gather together the .wav files containing the audio data you wish to put on the CD. These should be prepared as 44100 Hz, 16-bit files, to match the audio CD standard. You should also consider applying dither, if you're reducing bit depth in the conversion process. If you're using Audacity to export your audio material, the File > Export menu item defaults to .wav at CD sample rate and bit depth as long as Project Rate (Hz) is set to 44100 in the lower-left corner of the Audacity window. The dither options are located under the Quality tab of the Edit > Preferences dialog in Audacity. When you're exporting . wav files from Ardour, the sample rate, bit depth, and dither options are in the Export dialog, as you read a few pages ago.

Running gcdmaster from the command line or a menu item, the first thing you see is a small GUI inviting you to begin a new project. You're interested in the Audio button; it's subtitled "Create an audio CD from wav files" (see Figure 10-21).

Figure 10-21. Gnome CD Master has a simple start-up dialog.

Click this button to open a blank window titled unnamed-O.toc. This window title refers to GNOME CD Master's native project format, a text file listing the positions of the files relative to the start of the CD and where the track markers are (see Figure 10-22). The toc part of the filename stands for table of contents. It's a good idea to save your project at this stage with a more meaningful name; you must give it a .toc extension, because GNOME CD Master doesn't append the suffix automatically. File > Save As does the trick. Then, select Edit > Append Track. A file-selection dialog opens in which you can click on a suitably formatted .wav file. Next, click the Add button in the lower-right corner. The dialog doesn't close automatically, which lets you go on selecting files and clicking Add until your sequence of .wav files is complete. Then, click the Close button.

Figure 10-22. Add tracks one at a time, until your CD project is complete.

Returning to the main window of GNOME CD Master, you may have to resize or maximize the window before you can see the buttons to the right of the toolbar. The Zoom button allows you to inspect a selection of the waveform up close, perhaps to examine a section that is distorted. The Select tool enables cut and paste operations, which are found on the Edit menu. However, there is no Undo option, so edit carefully or prepare to restart the process of importing and appending .wav files.

When you're happy with the sequence of tracks, you can click the Play button to hear the entire CD via the default sound hardware on your system. Using the Select tool in combination with the Play button means you don't have to listen to the whole project from the start, just the part you're most interested in.

If you want to add a new track marker, click the waveform, and the cursor draws a red vertical line at that point. Then, choose Edit > Add Track Mark, and the new mark appears (see Figure 10-23).

Figure 10-23. Gnome CD Master enables both visual and auditory inspection of the proposed CD data.

If you have a burner that supports the format, you can use the CD-Text-related options at the top of the Edit menu to input metadata (see Figure 10-24). Note that if you want to use the Track Info option, you need to click the track marker immediately above the waveform to select it; the marker is highlighted with a red background. You can also choose Edit > Remove Track Mark when a particular track marker is selected.

Figure 10-24. CD-Text lets you include metadata, but not all burners support the feature.

Click the Save button again to update the .toc file, and then click Record. A burning dialog opens, listing the available recorder devices and their status. By default, the Simulate option is selected, which is a hangover from the days when optical drives suffered from buffer under-runs and blank media was relatively expensive. In a well-configured GNU/Linux system, you should be able to go straight to Burn without problems, but try the Simulate option if you wish.

Figure 10-25. You have the opportunity to simulate the burning process if you don't want to risk making coasters.

After burning has completed, a dialog prompts you to eject the disc. Because your .toc file has been saved, you can return another day to burn the same sequence again using the Open button on the initial GNOME CD Master dialog, instead of starting from scratch each time. That is, as long as you don't move the .wav files. If you do, the program doesn't know where to find them. Because the .toc files made by GNOME CD Master don't use full system paths, it makes sense to store the .toc file and the .wav files in the same directory.

GNOME CD Master has a detailed manual page that explains all the advanced features of the program, in case you want to dig deeper. To read it, open a terminal on any GNU/Linux system with the program installed, and type man gcdmaster

Then, press the Enter key. Doing so opens the manual page directly in the terminal; you can scroll through it using the up and down arrow keys on your keyboard. All old-school Free Software programs on GNU/Linux are packaged with this type of text documentation, for quick reference to command-line options. Just type man followed by a space and the name of the program binary.

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