Help me with gops .Arrggghhh

[simmo1]

For some reason keep getting gop errors after converting avi/divx etc to vcd. ok till i use tmpgenc dvd author then i get the error message saying 'video gop is too long'. I know theres loads of posts about gops on here but i just dont get it. in simple terms what is a gop and how can i sort this out and still use tmpgenc and tmpgenc dvd aurthor. sure i'm getting this error more since i got a newer version of tmpgenc dvd author.using 1.5.15.49 and 2.5 of tmpgenc.

[FOO]

It might be good if you tell us exactly how you converted
your AVI to MPEG , and with what program.
GOP is Group of Pictures. It starts with a complete frame , and
has several frames after that , based on differences from the
start frame. DVD specifications have a limit on how big they
can be , 18 for NTSC and 15 for PAL.
You set that in the encoder. You may have set it wrong

[simmo1]

i'm using tmpgenc to convert .use tmpgenc to merge two vcds together then use tmpgenc dvd author to

[FOO]

Well, make sure TMPGenc is set to make legal GOP sizes
Set it to 12 to make sure

and don't merge the files , put them in TDA separately

[simmo1]

will u still get a perfect join putting into tda seperately ? where is the setting for gop sizes . cheers.

[simmo1]

is it the 'maximum number of frames' i need to change to 12 ?