pixelating while panning

ZOOBOSS · Post by **ZOOBOSS** » Mon Jan 03, 2005 7:24 pm

Have video from a Panasonic GS200 at high quality. I brought in the video on firewire and saved on PC as AVI file. Used 8.0 to render the video and saved to DVD in MPEG2. All looks fine but the video pixelates big time during a panning shot. My next attempt, I used variable bit and raised the 'quality' and that helped make the pixelating smaller blocks but it is far more than I expected. I am aware of the MPEG2 design problems, but are there any other setting I am not aware of? Am I capturing the video wrong? Thanks for your ideas.

kebrinton · Post by **kebrinton** » Mon Jan 03, 2005 7:59 pm

Hi.

Did you author a DVD or "save to DVD" (don't actually know what that would mean).

If you authored in the usual way (see standard procedures described in Post #1 in forum), you should not have noticeable pixelation. Others will comment on this.

ZOOBOSS · Post by **ZOOBOSS** » Tue Jan 04, 2005 5:25 pm

kebrinton - great lead, because I am pretty sure I 'saved' the file to DVD. I will try the authoring route.

Thanks!

burgo · Post by **burgo** » Tue Jan 04, 2005 6:44 pm

Just as a matter of interest, did you change the playback speed of the clip ? I found in VS7 that when I slowed the clip down during a pan the click would pulse in and out of focus.

david reece · Post by **david reece** » Wed Jan 05, 2005 1:28 pm

dont use VBR and most certainyl dont capture as direct MPG2 capture.

i find for these shot use DV.AVI or AVI captureand then covert to MPG2 this gets rid of the pixelation effect. CBR seems to be better than vbr.

MtCastle · Post by **MtCastle** » Wed Jan 05, 2005 2:51 pm

David,
I got out the shotgun (American expression for being desperate and trying anything) last night to try and fix the flickering issue and I stumbled upon what is mentioned in your previous post. For me, using Constant Bit Rate (CBR) RESOLVED ALL OF MY FLICKERING!!!. I could use any transition and ALL of my pictures looked sharp. There was some slight pixilation on some of my pans but nothing like before. I am going to make a seperate post for this to see if others get the same response.
Gary M

david reece · Post by **david reece** » Wed Jan 05, 2005 3:01 pm

CBR means the rate is constant that data is read at. ie 6mbs will always be 6mbs.

VBR however will analyse a frame and disgard what doesnt need to be encoded. unfortunately with fast moving shots panning you will always get problems with direct mpg2 capture. direct mpg2 seems to have problems in VS8.

Honest DV.AVI is to MPG2 is the best way.

the adage is if you cut corners expect mistakes!

ZOOBOSS · Post by **ZOOBOSS** » Wed Jan 05, 2005 11:15 pm

david - when you say capture, I brought the video in on AVI, then when putting it to DVD is when the problem cropped up (I think). That is when I put it in MPEG2 format, but I think I may have saved it instead of authoring it - will try that. You a fan of variable bit?

thanks

david reece · Post by **david reece** » Thu Jan 06, 2005 1:18 pm

vbr i have found is only good if you have a near static video.

example at my Dad's 60th birthday his choir performed a concert for him.

it was ok until one of the members did this routine to act out the song. as soon this happened pixelation came into the video.

However the same clip captured as DV.AVI and then converted to CBR or VBR pixelation went altogether.

I do not or never advocate using vbr when doing direct MPG2 capture expecially if there is a lot of movement in the picture.

by the way what is your template and what is the quality slider showing on VS8.

The advantage with VBR is more video to your disc. the disadvantage is problems you have mentioned as well some DVD players cant cope with VBR discs that have been written onto DVD-/+ r discs. Dont ask me to name players. I have a wharfedale and it has problems with some vbr footage as well as upper or field b footage.

jchunter_2 · Post by **jchunter_2** » Thu Jan 06, 2005 3:17 pm

David,
CBR may be helping you with your problem but Variable Bit Rate or Mpeg encoding are clearly not causing these problems for many (most?) of the rest of us.

I have always captured directly to mpeg using Variable Bit Rate. My videos have lots of motion and panning and bright colors. I have never have had the pulsing or pixelation that you experience.

The underlying problems in Video Studio that cause your symmptoms are more subtle. Lets pull together and see if we can figure it out.

david reece · Post by **david reece** » Thu Jan 06, 2005 5:18 pm

the underlying problem has occured on two different systems!

i am speaking from experience and this is what i do if i get a problem when panning. if it doesnt help so be it. if it does another satisfied user!

ruggy1 · Post by **ruggy1** » Fri Jan 07, 2005 6:08 am

DV to AVI via Firewire needs as high a bit rate as you can manage, to reduce pixellation during motion. I usually use 9500. Makes the file bigger, but so what.