B-VOPs are EVIL

[vocoder]

I hate enabling B-VOPs almost always, as motion is periodically affected in such a way that it almost looks like frame drops at regular intervals. Even though enabling some can allow an even higher degree of compression, having this type of artifact is now completely unacceptable to me. Is there something else I should be doing (limiting B-VOP's doesn't cure anything other than eliminating them)? Closing the bi-directional sharing of course takes more space per those full frames, but at least I don't have this periodic jerkiness which looks like frame drops every 10 seconds (or whatever the interval) - its just so annoying that I always turn off that option now. Wish there was a way to benefit form the B-VOP compression without compromising with this apparent motion/frame drop'esque artifact. ;)

[stephanV]

i doubt the artifacts are caused by b-frames, unless you use a really outdated decoder. b-frames are used probably for half of all the frames under normal circonstances, so jerkiness with an interval of about 10 seconds seems a bit odd too...

[vocoder]

I doubt the artifacts are caused by b-frames, unless you use a really outdated decoder. b-frames are used probably for half of all the frames under normal circumstances, so jerkiness with an interval of about 10 seconds seems a bit odd too...

What do I know - closing B-VOPs eliminates those symptoms. It’s the one thing I can independently control for.

As for decoder, latest stable Kopei's & ffdirshow. Funny how closing the B-VOP option completely eliminates the problem :)

[Teegedeck]

Hit the 'load defaults' button and stop spreading false information. Thank you.

If you are referring to that HDTV-encode you struggle with (http://forum.doom9.org/showthread.php?t=98417) tell us so. Because it is quite obvious that your framedrops stem from too weak hardware then (B-frames are a tad harder to decode than p-frames so trying to decode HDTV content might more probably result in occasional stutter if you use b-frames).

*BTW, you're likely to trigger more sympathetic replies when you put it like 'I have a problem with b-frames' and not like 'b-frames have a problem'.*

[vocoder]

Hit the 'load defaults' button and stop spreading false information. Thank you.

If you are referring to that HDTV-encode you struggle with (http://forum.doom9.org/showthread.php?t=98417) tell us so. Because it is quite obvious that your framedrops stem from too weak hardware then (B-frames are a tad harder to decode than p-frames so trying to decode HDTV content might more probably result in occasional stutter if you use b-frames).

*BTW, you're likely to trigger more sympathetic replies when you put it like 'I have a problem with b-frames' and not like 'b-frames have a problem'.*


NOPE, its regular amorphic DVD. My 1080i stuff doesn't stutter like that, and more irregular (and only at pans&scans). Stuff I am having troubles with is run of the mill DVD originating probably from handhelds. But|comma comma| since you seem to be so good at reading my mind, why don't you tell me what I am thinking about right about now. :sly:

Lets all see how long this post lasts. Not too long is my bet.


“The opposite of self-(moderation) surely is self-indulgence.”

[unskinnyboy]

@vocoder, Half the civilized world encodes anamorphic DVDs to XviD using b-frames and haven't come across anything conclusive which said b-frames per se would cause artifacts or stutter, so how do you explain that?

So why don't we get off from 'b-frames is evil' mode and into 'b-frames doesn't work for me' mode and start troubleshooting this? Like you cut a VOB sample for us, post your avs script used, your hardware settings, decoder used, other XviD settings used etc?

[vocoder]

@vocoder, Half the civilized world encodes anamorphic DVDs to XviD using b-frames and haven't come across anything conclusive which said b-frames per se would cause artifacts or stutter, so how do you explain that?

So why don't we get off from 'b-frames is evil' mode and into 'b-frames doesn't work for me' mode and start troubleshooting this? Like you cut a VOB sample for us, post your avs script used, your hardware settings, decoder used, other XviD settings used etc?

OK, will have to get back to you with the specifics then. All I know is turning off the B-VOB's cures this symptom, and I can verify my CPU has plenty of cycles potential to render this moderate video. Could it be because I have both XviD and ffdirshow installed? Can I use XviD to encode only, and turn off the decoding functions of XviD, or is one of the dirshow decoders subordinate to the other? I'm shooting in the dark a bit here. One thing is for sure, my topic was taken with the utmost of seriousness. Whoa>

"Don't hate me because I'm stupid."

[Didée]

As for decoder, latest stable Kopei's & ffdirshow.
"Koepi" is the correct name for the former, "ffdshow" the one for the latter ...

Which version of ffdshow you're using?

Which decoder is actually used on playback time?

[vocoder]

"Koepi" is the correct name for the former, "ffdshow" the one for the latter ...

Which version of ffdshow you're using?

Which decoder is actually used on playback time?
Didee,

Not sure which filter is being used for playback (but I suspect ffdshow). On a completely unrelated note, did you happen to catch the Star Trek, Next Generation episode entitled "The Big Goodbye"?

Here is a refresher: "The U.S.S. Enterprise must pass through the quadrant Korona IV, which is inhabited by the Jarada, an insect-like race that demands a precise greeting from the Captain of any ship wishing to enter their territory."

I am a huge NG fan, and I hear there are many fans here too. I especially liked this episode.

[Didée]

Well, "I suspect ffdshow" sounds not all that reliable ... bring up ffdshow's config page from start/all programs/ffdshow/video decoder configuration, go to the tab "about", there the build's date is stated.
It is possible that you have an older version installed that has problems with B-frames in general, or perhaps an unoptimized build that simply lacks performance.

In case of doubt, head over to e.g. celtic druid's page (http://celticdruid.no-ip.com/xvid/), and get yourself an actual build of ffdshow. Remember to set ffdshow up to decode XviD (codecs/XviD=libavcodec and miscellaneous/IDCT=libmpeg2).
Then make sure no other codec is still overriding ffdshow. When playing an XviD file, go through your player's options, somewhere you should get information about the DS filters actually in use. Dunno which player you're using, so I can't give closer hint. Simplest way, however, would be to drop the file in GraphEdit and look at the filter chain.

Yes, I'm 99.9% sure I have that episode, but have to admit I can hardly remember it right now. Alltogether I missed two or three of all the episodes ... one of them was "Time Squared", which is among my top favourites :( - But they repeat it all time long, so no drama ;)

[vocoder]

Didee,

Tnx for the quick help here - much appreciated. Will have to get back to you all once I do more fiddling & research. Thanks again to all who have offered constructive help.

Best,

Voco