scene change threshold

[bira]

Hi !

Can anybody tell me what scene change threshold means ?

What do I get when setting scene change threshold to 0%, 50% or 100%?

Thanks !!

[DJ Bobo]

why don't you try yourself?! is it that hard?!

You don't have to change it anyway, the 50% setting is perfect IMHO.

[bira]

Originally posted by DJ Bobo
why don't you try yourself?! is it that hard?!

You don't have to change it anyway, the 50% setting is perfect IMHO.


Wow, thank you very much. You perfectly explained what it means.
You did help me a lot !!

[DJ Bobo]

@ bira
you're welcome!

[Acaila]

Scene Change Threshold determines how much difference there has to be between the current and the last frame before the current frame is turned into a keyframe.
Ideally keyframes are placed on the beginning of each scene, with only normal frames (P-frames) in between. A higher threshold might not detect frames that should have been encoded as keyframes. A lower threshold will turn frames into keyframes that aren't nessecary (and thus make that frame larger than it should have been). A value between 50% and 60% is usually good enough.

[bira]

Is it possible that DIVX 5.02 is not detecting scene changes as it should ? If so, what should I look into?

I am using the Gknot 0.26.

Thanks Acaila

[Acaila]

Theoretically it's of course possible that it's not detecting scenechanges correctly, however a few missed or a few added keyframe won't make a big deal. The default works very well for everyone.
If however it is missing a lot you should decrease the threshold by 10% or so, if it adds a lot increase it by 10%. Try out a few encodes to see how it's responding and modify the threshold to what works best for your case.

If you're using GKnot then you won't have the option of changing the threshold. Only when you use VirtualDub will you have full control over all the features.

[bira]

Will try!

Thanks!