Q: green screen

See:

iTunes: May be unable to transfer videos to iPhone, iPad, or iPod

iTunes: Frequently asked questions about viewing and syncing videos

You may need a computer app like the free HandBrake to convert the format to one compatible with the iPod.

Wow, I guess I read the question.

Have you tried to restore with DFU mode through iTunes?

DFU mode = Device Firmware Update mode

DFU mode is a mode where the iPod Touch/iPhone will be made to force a restore of the firmware into whatever version firmware it is given. Getting your iPod Touch/iPhone into DFU mode is somewhat tricky, and it may require some patience/practice because timing is essential to get it to DFU mode and not into recovery mode.

1. First, Open up iTunes, plug in your iPod Touch/iPhone to the CPU's USB port. Turn on your CPU's speaker and make sure it is loud enough that you can hear it.
2. Hold down the Home button (top left for iPod Touch and top right for the iPhone with the screen facing you) and the Power button (located on the front bottom of your iPod Touch/iPhone) simutaneously, until the screen goes black and the device turns off. (past the red slider/slide to power off screen "don't touch that slider").
3. Now let go of the Power button, but continue to hold the Home button. Your iPod Touch/iPhone should have turned off and the screen should not be on.
4. After around ~10-20 seconds, you will hear a noise (beep/ding) from your CPU as if it had just recognized a new hardware device, now iTunes should recognize it in DFU/Recovery mode.
5. After iTunes recognizes the iPod Touch/iPhone, let go of the Home button otherwise it will go into recovery mode and you will have to do the entire DFU process over again.
6. You will know when you have put your iPod Touch/iPhone correctly into DFU mode when the display is blank and that you do not have anything on your device.
7. Now proceed with the recovery process and it should update to the iOS6.

Good luck!