hi, i recommend you Aiseesoft Total Video Converter.
it can convert HD video easily.
it can convert videos to MP4/MKV/WMV/AVI and other popular formats such as: H.264/MPEG-4 AVC, FLV, MPEG-1, MPEG-2, 3GP, 3GPP, VOB, DivX, Mov, M4V, DivX, XviD, ASF, SWF, VOB, DV, Super VCD(NTSC, PAL, SECAM), VCD(NTSC, PAL, SECAM) , DVD(NTSC, PAL, SECAM) and HD video etc with high speed and excellent sound/image quality.
Free download it here:
http://www.aiseesoft.com/total-video-converter.html
here is how to use it:
Step 1: Click the "Add File" button to load your video
Step 2: Select the output profile
Step 3: Output Video settions.
You can cut a clip of your video by using its "Trim" function
You can merge a few videos into one file by clicking "merge into one file"
You can crop the black edge of your video to adjust your video to your iPod screen to get the best view.
Step 4: Click the "Convert" button to sart the conversion.
Just have a try and i hope it can help you.