KWiideo is a video encoder for the mjpeg codec, which is supported by the Nintendo Wii.
You can use mencoder or ffmpeg as encoder. If you want to add subtitles you have to use mencoder, because ffmpeg cant add srt files to videos (maybe ffmpeg can do it, but didnt found a function for it).
You can set the quality of the output video using the quality slider. Available values 1 (best quality, largest files) to 30 (poor quality, small files). An other way to change the quality is setting the bitrate. High bitrates create better quality, but the filesize increase. It is not possible to use the quality slider and the bitrate setting function at the same time. Changing the bitrate seems not to work with mencoder and mjpeg as codec, you better take the quality slider when you use mencoder as encoder.
For splitting the video, you need avisplit. Comments are welcome.