KVCD: B-picture spoilage ?
 

Hi all,

I'm encoding mpeg2 kvcds, and it works really nice. Compared to
the standard svcd settings, the kvcd settings don't have a "b-picture spoilage" when encoding.

I've encoded a 20 minutes mp2 with and without the b-picture spoilage set to 20.

The result is as follows: the file with the spoilage is smaller than the file without the spoilage (=logical), but I don't see any quality difference.

The result is that I can now encode with a higher cq value....

But what does the b-picture spiolage anyway?

Should I continue with this or not?

thanx!

On short GOP lengths it's ok ... as in your case you're happy with.
KVCD = max GOP length = 24 ... thats not that very much (in case of a OneCD encoding template, and thats also why you don't see a big difference BUT!: This also depends on the Bitrate you are using to encode and many other factors. So it can't be determined in general.

But on longer GOPs as this means more far far away "bi-directional" references to the previous/next I frame ... the quality at the frames within the half of the GOP could suffer.

http://www.digitalfaq.com/archives/i.../2003/11/1.gif
Imagine that there will be a reference to the next I frame too.

Also explained here:

http://www.broadcastpapers.com/sigdi...-%20comp09.htm

8O

Hmm, okay, i think i get it now. :D

Thanks!