GOP Structure

[FoxGarrison]

Can anyone please explain or direct me to a technical tutorial regarding the GOP structure in TMPEGEnc? I'm particullarly interested in finding out for what it is used. Will it affect the quality of the conversion if I fool with this option? Will it affect the size of the final MPG?

Thanks

[kitty]

Check out these FAQs:
http://bmrc.berkeley.edu/frame/research/mpeg/mpeg_overview.html

And send a message to user kwag, he is king of GOP twidling.

[FoxGarrison]

Thanks, Kitty!

[Betamax]

Quality also depends on GOP structure.

For animation, this GOP is most suited : IBBPBBPBBPBBPBBPBB (1xI, 5xP, 2xB).
For movies (not animation), this GOP is most suited : IBBPBBPBBPBB (1xI, 3xP, 2xB).
For DVD, 2 types of GOP are mostly used :
- IBPB (1xI, 1xB, 1xP)
- I (1xI, 0xB, 0xP)

When encoding using TMPGenc, also check the box 'Closed GOPs' : Some applications for building a S/VCD (lkVCDxBuild, VCDxBuild) can give problems when 'open' GOP's are used.

[SLK001]

For DVD, 2 types of GOP are mostly used :
- IBPB (1xI, 1xB, 1xP)
- I (1xI, 0xB, 0xP)

Not true... the DVD spec specifically states that "Low Delay GOPs are NOT permitted". Low delay means the absence of "B" frames (because of the way they have to be juggled in the player, there is a delay between the time they are decoded and the time they are played).

I use IBBPBBPBBPBB for both live and animation encoding. Most Hollywood disks (that I've seen) use this GOP.

[jfebus]

will the I (1xI, 0xB, 0xP) structure give compatibility problems?
Wil it affect the forward funtion in a dvd player?

Regards,