koepi's XviD-09112002-1 build and B-frames

[vinetu]

GREAT Quality !!!

Bug:

Playback of B-frames encoded avi files is impossible without dropped frames
except for ULTRA-HIGHMotion scenes.Both DShow and VFW.

however this nic's DirectShow filter can handle this:

http://free.techno-link.com\vinetu\temp\xvid_ax.zip

this DShow filter can't handle """GMC+B-frames""" BTW...


BEST REGARDS!!!

[Nic]

@all:
Sorry for the lack of updates to my DShow filter. Ill try & compile a new one tomorrow & make sure my latest source code is up so it can be recompiled by others when im busy.

Cheers,
-Nic

[Gazza]

Nic,
I have noticed in the recent builds (maybe since end Oct onwards) that playback of video if using b-frames is very choppy. In other words, frames seem to get dropped and the image jerks along. I get some relief by re-installing old encodes (avid.ax).

If I encode with qpel and gmc together or on their own then the playback is relatively smooth.

Here is some results of the various tests I did with Koepi's 9 Nov build. I took a single vob and processed it as a small sample to compare different methods.

b frames only 18,338kb - dropped frames
bframes, qpel & gmc 18,402kb - dropped frames
qpel with gmc only 19,994kb - smooth, no apparent dropped frames.

Is there any way to get smooth playback on the b-frame encoded videos?

Gazza

[Acaila]

It is a known problem with DivX5 that using B-frames increases strain on the processor by quite a bit (because more frames have to be decoded . Anything over 1GHz should play such a movie smoothly though. What speed is yours?

[nexus]

I had the same problem (dropped frames). My solution: I reinstalled the 04112002-build to decode the movie (encoded with 09112002-build with b-frames).

[MaTTeR]

Dropped frames here too on one of my machines, dual PIII 800. Dual XP 1600 system plays smoothly though. Thinks it's about time to dump the PIII system and get another XP1600 :D

[kastro68]

is anyone else having serious problems with gmc enabled?

[Rrrough]

12.11.2002 15:00:
U xvidcore/src/encoder.c (rev.1.76.) syskin:
- gmc + bframes fix
U xvidcore/src/motion/motion.h (rev.1.13.) syskin:
- gmc + bframes fix; much smarter p/b/i decision
U xvidcore/src/motion/motion_est.c (rev.1.44.) syskin:
- gmc + bframes fix; much smarter p/b/i decision
guess it's already fixed in CVS...

[Trahald]

My 950 mhz Duron has trouble with 09112002-when using b-frames too... dropped frames and such. When i use FFDSHOW to decode its smooth but i get weird artifacts.. for now the artifacts are easier for me to accept so i'll live witht hem until a. i get a faster processor (maybe in 2005) b. the decoder is kinder to my processor.. hehe. if ffdshow decodes smooth then i know its possible. just have to cross my fingers ;)

[cult]

How do you tell dropped frames?If you mean when watching you lose synch,then I dont have dropped,unless I cant see them.Used 9/11 build and ffdshow(the new alpha).No artifacts by the way even with the older alpha ffdshow.Used 3/150 and chroma estimation for this movie.When gmc were used I had some artifacts appearing.
The only thing I can tell is that the movie appears too smooth if you know what I mean.Not even noise appearing.In a previous encode of the same movie I had to use c3d to take off the noise.Now I had to take off c3d from the avs!Thats strange...Can someone explain plz?
I use a celeron@1ghz,256mb of ram,w2k and radeon 8500...
Oh,all these when I dont check use xvid.
Otherwise terrible dropped frames:sly:
Sorry If misleaded anyone

[Rrrough]

the movie appears too smooth if you know what I mean. did u use b-frames in your first encode ? did u use MPEG quantization (resp. MPEG-custom or any flavor of modulated) then ? b-frames are only working with H.263 quantization, which is smoothing quite a bit.

cheers

[cult]

I used bframes(3/150)for both passes and mpeg 1pass new modulatedHQ for 2nd pass.It doesnt work this way yet?

[Rrrough]

As soon as you enable b-frames, you'll get h.263 quantization (in 1st and 2nd pass) resulting in a smoothed video, as stated. your selection of quantization method will be overridden then. this will hopefully be fixed soon.

cheers

[cult]

ah thats why!thank you

[Gazza]

Originally posted by Acaila
It is a known problem with DivX5 that using B-frames increases strain on the processor by quite a bit (because more frames have to be decoded . Anything over 1GHz should play such a movie smoothly though. What speed is yours?

I have a 1Ghz P3 with 512M. I find it a little strange though that going back in build revision results in a smooth playback. Does this mean that the current xvid.ax has problems?

I'm attempting a test encode with qpel+gmc and no b-frames. My initial tests seem to indicate that there isn't too mach appreciable quality difference with and without b-frames (even though the final file size is smaller). In this case does smaller file size really give you better quality?


[edit] In other words I don't think processor power comes into it as b-frame encoded movies look great with older xvid.ax.

[nexus]

Latest ffdshow filter decodes b-frames correctly! So, it seems to be a bug in the xvid.ax.

[vinetu]

Thanks for information, nexus !

I'm just wonder -install or not to install ffdshow...

however, xvid.ax and ffdshow are a DirectShow filters so
this is the half of things - ffdshow cannot
replace VideoForWindows decoding - the VirtualDub way of decoding
xvid files - here is xvid.dll ... with the same malady :)...

[Bulletproof]

It seems you can't use GMC with DX50 FourCC used with this build either, you just get a green picture. But I think I remember the older build being able to use GMC with DX50?

EDIT: My apologies, GMC seems to work fine with DX50, I had the Interlaced Video option enabled and the DivX decoder doesn't seem to like that or just doesn't have the support for it.