PiTiVi is a video editor for GNU/Linux that supports importing and exporting Ogg Theora videos. Right now it supports basic editing, cropping clips, arranging on a timeline and adjusting of audio levels.
PiTiVi has its own documentation that you might also wish to read located online at http://www.pitivi.org/wiki/Manual#Proposed
There is also a very good manual available in PDF format that you can find online at http://jeff.ecchi.ca/blog/?p=897
PiTiVi only works with GNU/Linux. If you have Ubuntu Jaunty (9.04) you can install a very useful version of PiTiVi from the command line (terminal) with the command :
sudo apt-get install pitivi
You will be asked for your password, when you enter it the installation will proceed automatically.
When the installation is complete you can open PiTiVi from the Applications menu (listed under Sound & Video).
You can also check http://pitivi.org/wiki/Downloads for instructions to install newer versions. PiTiVi is actively developed right now and there are new releases coming out regularly.
Once you opened PiTiVi you can press the plus (+) button in the interface to Import clips.
Imported clips are added to your Clip Library. You can use all formats that GStreamer accepts. If you don't know what this means then the easiest way to know what files work with PiTiVi is to play them in Totem (found in the Sound and Video Applications menu and titled 'Movie Player'). If a file can play in Movie Player then it can also be used as a clip in PiTiVi.
You can continue adding as many clips as you like to the Clip Library (the video of the Digital Clock is created by Riccardo Iaconelli).
Once you imported the clips you want to use, you can drag them from the Clip Library on the timeline below.
If you add multiple clips to the time line they will appear as slightly different colors and with the filesnames displayed :
If you can't see this kind of detail then use the zoom tools to zoom in and out of the time line :
When the clip is on the timeline you do not see the individual frames, but you can drag the slider backwards and forwards in the player area to see the video.
When you play back video like this you can see the position (time) of the playback displayed by a red tracker on the time line :
You can move the clips around by dragging them around the time line.
To cut a clip in two you need to click on the scissors icon :
Then move the cursor around the time line. You will see an orange line appear showing the potential position of the cut :
When you have the orange line at the right place click on the timeline and the selected video file will be cut in two at that point.
To delete a clip, click on it with the cursor so that it is selected and then press the Trash Can icon :
Export to Ogg Theora
Once your project is ready to be exported, you can click the Render Project button :
You will now see the Render settings window :
Click Choose File to and choose where to save the exported file to. You could also adjust the encoding settings pressing Modify, once the settings fit your needs, press Render and get a coffee.