GUI application for converting/resizing videos

[Marcelo Magno T. Sales]

People,

I usually convert/resize/transform video files using avidemux, with good 
results. However, I have here some high resolution video files 
(1920x1080 @ 60 fps) generated by a Sanyo camcorder that are played 
correctly, although slow, in kaffeine, but are not read correctly in 
avidemux.
avidemux shows the lower half of the videos completely distorted and the 
upper half out of proportion. When these videos are converted to other 
formats or even transformed in any way and saved back with the same 
codec avidemux had detected in the original files, the resulting files 
are completely useless and their sizes are about 5 times the sizes of 
the originals.
Any ideas on why this happens?
Is there other GUI applications in fedora repos that can 
convert/resize/transform video files?

Thanks,

Marcelo