Desparate!! help needed :MPEG2 files locate an I frame

I would like to get some help on how to locate an I frame from an MPEG2 file.
I have a hardware decoder and am able to play the Mpeg2 files and see the output on a TV connected to the decoder output. Now I want a thumbnail view of the MPEG2 file on the PC monitor.

Thanks in advance

[CGhijselinck]

You ask for an encredible complex thing ! Do you decode real time MPEG2 Transport or play back MPEG2 program ( system ) stream? I have some WIN32 software ( + sources; compiled with VS6.0 ) that I called an MPEG2 "slider" , since it's maximum decoding speed is 5 fps on an 200 Mhz MMX. It is only able to decode "program streams". May be you can change the code so that it decodes only the I-frames and leave the B-frames and P-frames. E-mail me at "Christiaan.Ghijselinck@Wol.be" for the source code.