Using GNUsound

GNUsound can be installed with little pain on most GNOME 1 or GNOME 2 installations.

If installation has been successful, there should be a GNUsound icon in your GNOME menus. Alternatively you can start GNUsound from the command line:

$ gnusound

This latter method is actually recommended (at least for the time being), because GNUsound spews copious output to the screen, including some error messages that haven't found a place in the GUI yet (such as when GNUsound cannot open the audio device).

If you run into problems, e.g. GNUsound won't start, or it crashes immediately after startup, see the installation section and read the output from

$ ./configure --help

GNUsound uses libaudiofile, which is a part of GNOME, to provide support for a number of popular audio file formats such as .AIFF and .WAV.

You can create a selection on a track by dragging the mouse pointer over the region that you wish to select, or by holding the SHIFT key and giving one of the movement commands in the Select menu. You can select multiple tracks by holding the CONTROL key while clicking on the tracks that you want to select. If a track is already selected, then this action deselects the given track. It is also possible to select multiple tracks by issuing the Track Up and Track Down commands from the Select menu.

Changes to the selection are undoable, thus, if you make a mistake which causes you to lose an important selection, you can issue the Undo command to get your selection back.

A handy trick to temporarily save a selection that you don't want to lose while you do some editing elsewhere is to turn the current selection into a loop, then do your stuff, and then to select the loop when you're done. Alternatively, you can set cuepoints to demarcate the selection that you want to save, then use Snap to Cuepoints and the Move Left and Move Right commands to get your selection back.

GNUsound can playback as many tracks as your hardware can handle. Every track can be mixed onto as many output channels as desired, using the mixer level controls (the rainbow colored things).

GNUsound does not perform any implicit transformations of the audio file on playback[2]it just tries to open the audio device with the same parameters as the audio file (number of bits, sample rate) and starts playback. You should check GNUsound's output for any warnings (e.g. when the device could not be openend, or when the audio device can't support the requested sample rate -- these warnings do not appear in the GUI yet).

GNUsound does not perform any checking on output clipping: it is your responsibility to make sure you don't mix two channels too loudly.

GNUsound can record as many tracks simultaneously as your hardware will bear. You do this by selecting the tracks you wish to record on and issuing the Record command.

There is no relation between which tracks are selected and which input channels are actually recorded except for the number of channels: that is, if you select tracks 1 and 3 and then start to record, track 1 will receive the first input channel, and track 3 will receive the second input channel.

There is currently no way to explicitly control which input channels GNUsound records from. GNUsound will always incrementally assign the available input channels to the selected tracks. If there is one selected track, GNUsound records from the first available input channel, if there are two selected tracks, GNUsound records from the first two input channels, etcetera.

You can issue the Save command at almost any time. Files are saved in the background and it is possible to perform almost any operation during a file save, including playback (although playback may stutter depending on your system configuration). Files are always saved in the .WAV format. Envelopes, cuepoints and other data are saved in a filename.usx file, in a fairly self-explanatory text format.

GNUsound currently stores all its data, including clipboard and undo buffers, in memory. Ultimately some logic will be implemented to offload portions of that to disk, but for the time being you have to be a little considerate to prevent GNUsound from swallowing all available memory. One tool to help with that is under the Debug menu, where you can find the option Destroy Undo. This destroys all undo's, thus releasing all memory in use by the undo buffers. Of course you should only use this option when you don't need those undo's.

If GNUsound crashes it will attempt to save data in open and modified buffers. It tries to save that data to the file filename.crash. No guarantees though -- if GNUsound crashes, it's because something is seriously broken, and basically all bets are off.



[2] There is one exception: GNUsound can convert signed 8 bit samples to unsigned 8 bit samples for drivers/devices that do not support signed 8 bit output. Whether GNUsound does this is controlled by the playback_signed_int8_to_unsigned_int8 parameter in the configuration file.