In the export-audio tab you can set the audio settings for your export file. Select the frequency, audio mode, and quality here. If you do not want to export audio data disable the "export audio data" checkbox.
Normally it should be enough to export audio for every 5 frames. You can set the desired rate here.
The export-range tab allows you to set a range of the timeline you want to export. If you want to export the complete timeline just select the “export complete timeline” radio button.
Sometimes there are distortions either on the top of the film or at the bottom. The crop function enables you to delete lines manually.