Frame blurriness every few seconds?

[RogerWilco]

Hey guys,
I've searched around but I haven't found any significant info on this issue. The frame seems to become "blurry" every few seconds on some of my encodes. Certain encodes seems to be more affected than others and the effect seems worse when using deblocking. I am thinking this must have to do with B-Frames and post-processing, but I honestly have no idea. Can anyone enlighten me?

Thanks!

[foxyshadis]

Do you have high quants/low bitrate? Once you pass 6-8 on p-frames the default b-frame settings start to look pretty bad. (xvid status window helps heaps with this.) For low to mid quants, you can try the 'golden ratio' of ratio 1.66, offset 0, or go the other direction with ratio 1.1-1.2, offset 2-3, if your quants are really high.

You should also try encoding part of the source where you know it happens without b-frames, just to be sure it's not something in the source.

[RogerWilco]

Thanks a lot for the reply. I believe the settings I used for this particular vid was a constant quant of 3 with bframes = 2,1.5,1. I have since started using 2,1.66,0 so maybe that is why I see it more in some than in others. The source isn't exactly the greatest either. It's the Blazing Saddles DVD. Great movie but the DVD quality leaves something to be desired.
I have seen similar issues with better sources though. Maybe I'll try raising the quant a smidge and eliminating b-frames all together.

Thanks!

[RogerWilco]

Well I was doing some testing last night and I relaized that the effect was so apparent because the source has the problem. It looks like a bad telecine job and running it on a progressive scan player (a computer in this case) brings out the worst in the telecine quality.

Thanks again for the help.

[Guest]

Maybe someone deinterlaced 3:2 pulldown material.