Next: the title properties window
Clicking in edit->preferences will show the preferences window:
Here is possible to set several options.
The first one is Erase temporary files, which allows to choose if you want DeVeDe to erase the temporary files as soon as they are needed no more. Selecting it, DeVeDe will need only about twice the final disk space, but if you don't mark it, you will need about three times the final disk space, but you will have all the temporary files to analize them.
The next option, Use optimizations for multicore CPUs, when marked, makes Mencoder or FFMpeg to use several threads to convert the videos, thus getting advantage of multicore CPUs to run faster. But it can produce some artifacts, so if the picture quality is not good, try to disable it.
The next option makes Devede to use FFMpeg instead of Mencoder. This code is still experimental, but also quite stable, so you should be able to use it without problems. If you experience coding problems, try activating this option.
The next option allows to specify where Devede will store the temporal files for previews.
Finally, the AC3_FIXED workaround activates a workaround for some Mencoder versions. If you experience sound problems when using Mencoder, you can try to activate this, or change to FFMpeg.