How to convert any video format to iPod / iPhone and be able to watch it?

Videos on the computer of 3GP, ASF, AVI, FLV, MOV, M4V, MPEG, etc format cannot be played on iPod touch, iPod nano, or iPhone if you transfer your video directly to iTunes. You must convert your video format to other which is accepted by your iPod/iPhone device (mp4).

DVDFab video converter can convert any video to iPod and iPhone professionally, with high quality output and no erros.

A step by step guide of any video to iPod / iPhone converter:

Step1: After downloading DVDFab video converter from here, launch it and choose the video converter - iPod/iPhone tab.

Step 2: You can click start and leave all the default settings of the video to iPod/iPhone conversion; your video will be ready (E:\DVDFab in our example)on the target you specified and you can sync your video/audio to your iDevice. If you want to adjust the settings for more advanced issues, you can continue with this tutorial..
To add a subtitle file and watching your videos with subtitles:

To adjust video effect settings, click the video effect settings button:
There will be two options available for customizing you video :
Resize Option:

Choose the frame resoultion and check the output preview, to make sure how your resolution will be affected. On the left bottom corner you can check all your video parameters to make everything clear for you and easy.

Crop Option:

In this option, you can cut the black edges and the undesired area, you can insert it by numbers top,left,bottom,right to make the crop accurate.

The slider letterbox to Pan&Scan can change your output scale.
LetterBox: is a widescreen aspect ratio
Pan&Scan: is an aspect television ratio

Finally: Click the start button to begin converting your videos to iPod, or your iPhone. Your converted files (output) will be written on the target directory where you can choose your own folder where you want your output be written.