Constant number of B-Frames

[last_hippie]

Hi,

is there any way of setting a fixed (constant!) number of consecutive B-Frames (e.g. 4) in XviD?
I need so many consecutive B-Frames for temporal Adaption (e.g. frame-dropping) in MPEG-4 Streams.
My current encoding-results show that i get at most(!) 2 consecutive B- frames in most cases, although i selected 4 B-frames in the settings.
Any hints?

Thanks

[sysKin]

Originally posted by last_hippie
is there any way of setting a fixed (constant!) number of consecutive B-Frames (e.g. 4) in XviD?
I need so many consecutive B-Frames for temporal Adaption (e.g. frame-dropping) in MPEG-4 Streams.
My current encoding-results show that i get at most(!) 2 consecutive B- frames in most cases, although i selected 4 B-frames in the settings.
Any hints?You want that in VfW I guess? There is no problems if you're using xvidcore directly.

Anyway, just set your max to 4 and set b-frame sensitivity horribly high.
I don't understand why you need it but I guess you have a reason.

Radek

[last_hippie]

Am I right that I can only achieve this by using xvidcore in an own application, or is there an other way of doing this quickly?

I need it for an academic research topic, where we are developing a mpeg-4 streaming proxy, that is able to adapt mpeg-4 videos to certain circumstances, like bandwidth, or limited display size (PDA), and so on. And a lot of consecutive B-Frames is helpful for using a quality based framedropping strategy.

[Koepi]

Originally posted by sysKin
Anyway, just set your max to 4 and set b-frame sensitivity horribly high.


sysKin already answered that...

[sysKin]

Originally posted by last_hippie
Am I right that I can only achieve this by using xvidcore in an own application, or is there an other way of doing this quickly?In your own application, you can simply force the frametype you want. This is why I said it was easy ;) .
In VfW (or, again, in your own application if it suits you better) you can use high b-frame sensitivity instead. The advantage of the second solution is that you'll still have keyframe detection.

[last_hippie]

Thanks, it works now.

My initial problem was, that i didn't find the switch for B-Frame sensitivity. Now I found it under "Zone Settings"(which I never used since RC1) as "BVOP Sensitivity" and set it to the maximum of 10.

[Koepi]

bvop sensitivity has no maximum (like 10)?!

Incredibly high means i.e. 50 or more as sensitivity.

Regards
Koepi