All this stuff has been examined a long time ago and everything works.
Here is the link to description in russian, maybe google translate can help you with this.http://chdk.clan.su/load/2-1-0-2
In any way there are a lots of pictures so it should be easy enough to understand.
In short: you will need to convert your video using VirtualDub with fallowing parameters - mjpeg codec (subsampling 4:2:2), 15 fps, resolutions 320x240/160x120/640x480.
Then save as AVI from VirtualDub and use this tool to create THM preview - http://chdk.clan.su/load/0-0-0-2-20
PS: Before editing video in VirtualDub you should install MJPEG codec (http://download.accusoft.com/picvideo/PICVIDEO.EXE
), you can find registration data in the archive below with test video.
Here is converted sample movie, try will it play or not.
Codec serial number included as a bonus http://www.multiupload.com/BEPW6LTPXJ
PPS: This is PHOTO CAMERA, not a multimedia player