Inserting Keyframes in 2ndPass??

[crOOk]

It would be nice to have a feature that lets you set some keyframes in the XviD controls.
I sometimes import the chapters of a dvd into the ogm format and noticed that I can't jump to the exact start of a chapter.

[-h]

This is more the job of a stats file editor..

-h

[crOOk]

Why do things with a stats editor if you can do them internally? Wouldn't it be cool to have an integrated stats reader/analyzer in the XviD Control Panel?

[-h]

If someone wants to write the code for it, sure :)

-h

[Koepi]

I can send you the stats reader sources, if you want to add that on another tab... :)

Best regards,
Koepi

[Emp3r0r]

This is more the job of a stats file editor..So this IS possible? I thought it caused repercussions that could only be fixed with a 3rd pass. It would be very nice indeed if we could feed XviD a simple list of frames we wish it to force as keyframes.

[Nightweaver]

Just adding my support for the idea. Compared to the rest of the things in the stats reader, I can imagine it being relatively simple to implement ... unless Emp3r0r is right, then you might need a bit more work. Oh well, I'll be optimistic for now ;)

[Koepi]

Sure, I could easily make an import function for a iframes.txt file which only consists of the iframe positions you want to force, e.g.:

1
2
1024
65535
133245

Would be a quick hack - but it would make necessary to use the statsreader. I thought of an implementation within XviD's VfW GUI, which is unfortunately written for win32 API and not for MFC... so it would be a real workload to implement it there...

Regards,
Koepi

[-h]

I thought of an implementation within XviD's VfW GUI, which is unfortunately written for win32 API and not for MFC... so it would be a real workload to implement it there...

Exactly :(

However instead of adding a function to import a list of desired I-frames, couldn't these frames just be set to I-frames in the stats reader/editor, since its needed anyway?

-h

[MoonWalker]

Hmm...This whould be good cause it whould be a solution to the prob where XviD "forgets" some I-Frames on the 2-pass pass. We whould generate an iframe.txt with the 1-pass I-Frames + (wherever else you need I-Frames) and feed it to XviD so it doesn't recalculates I-Frames.

MoonWalker

[Emp3r0r]

/me is trying to keep interest up

So, would Xvid need to know the frames before or after first pass to work correctly?

[Koepi]

XviD doesn't recalcualte keyframes, I wrote that already, didn't I?
It takes the iframes from the first pass (from the statsfile) and forces them to be in the same place on the second pass. We're still searching were iframes get lost as there seems to be no flawed code :-/

So what you want is a modified statsfile with the keyframes forced in places you define.

[Wuntvor]

Wouldnt it be best for the codec to now the "forced chapter I-Frames" in the first pass?
Otherwise the codec might decide to make an I-frame a couple of frames later and then when you add these forced ones in the second pass you get a double , maybe a few p-frames in between , that is unnecessary?

regards
/wuntvor

[Koepi]

It would be of advantage to know that in the first pass, that's true - the 2nd pass overflow treatment won't need to compensate for an "unpredicted" iframe which will be definatly bigger as the corresponding pframe.

But that would mean some ugly hacks in xvid, I don't know if it is THAT desireable/imnportant to do that.

Regards,
Koepi

[crOOk]

Originally posted by Koepi
Sure, I could easily make an import function for a iframes.txt file which only consists of the iframe positions you want to force, e.g.:

Sounds great! Maybe we could also import a chapter list file one day...

Originally posted by -h
If someone wants to write the code for it, sure
Maybe not.