Red's showing up pixelated in vertical bands

jrazz wrote on 9/5/2006, 7:03 PM
Here is the background:
I am working on some footage that has been letterboxed. Two cameras are hi-def A1's and the other is a standard def JVC. The A1 footage was downconverted in camera and letterboxed during conversion to match the jvc footage. I added color balance and brightness and contrast to the track and to the individual events I added Levels and HSL Adjust.
I am viewing this on a 42" LCD HDV TV. I am hoping that is the cause of the problem- watching standard def on a hi-def tv. When I view it on a 13" standard def tv I do not see the pixelating bands. If anyone has any suggestions, that would be great.


Details:
The Color Balance is set at: Red -.0570 with the others at 0 only affecting midtones and preserving luminosity.
Brightness is set at .10 Contrast is set at -.13 and the contrast center is set at .12
Levels is set at all channels with a gamma of .7 inputs are at 0 and output is at 1.
HSL Adjust hue is set to 0 and Saturation is at 1.58 and luminance is at 1
I output to 29.97 mpg-2 at variable 6-8. I also output to 24p with a constant of 8 after trying the variable and the 24p looked even more pixelated.

*Also, I have a sound clip that had a drop in it and was wondering if anyone out there with better audio knowledge than myself (just about everyone) could take a crack at matching audio from a shotgun to the wireless lapel as best it will go. I can post the files as wavs. They are extremely short clips- 2.08 seconds.

Edit: Links-
Shotgun Mic that needs to match the Wireless
Wireless Mic


Thanks,

j razz

Comments

GlennChan wrote on 9/5/2006, 7:54 PM
You could try using the Color Corrector's saturation setting instead... it is a different algorithm, based on Y'CbCr math instead of HSL. HSL saturation looks tacky IMO, and is not very perceptually correct.

2- Would you have some frame grabs? That might communicate some aspects better.
jrazz wrote on 9/5/2006, 8:02 PM
Yep. Here they are.

Screenshot 1

Screenshot 2

Screenshot 3

j razz
jrazz wrote on 9/5/2006, 8:04 PM
Like I said though. I don't notice it on a 13" Standard Def tv, but I do on the HDTV and on the computer- but it is not as bad as the HDTV.

Maybe I just need to test it out on a standard def tv that is set up well.

j razz
farss wrote on 9/5/2006, 8:08 PM
Yes,
many HD sets do a horrid job of scaling SD.

You wireless mic clip seems to be empty.
But trying to match the sound from too such vastly different mics isn't easy. I've tried matching a dynamic vocalists mic with a LDC, nigh impossible.

Do you have SF?

If so try using the spectrum analyser to give you a clue as to what Eq might help however as the pickup pattern is so different you'll have a big shift in ambient as well as response.
jrazz wrote on 9/5/2006, 8:15 PM
You wireless mic clip seems to be empty.

I fixed it- I had the track muted when encoding.

As for Sound Forge. I used the trial a while back, but it expired and I do not own a copy of it.

Thanks for the tip though- spectrum analyser. I may have to download the trial again.

j razz
farss wrote on 9/5/2006, 9:55 PM
As expected your lapel mic has way more bottom end, start with a low shelf on the lapel, obviously some experimenting is required.

If you have audio from both you could also try mixing the two, just the bottom end from the lapel, keep the highs out of the mix or you'll probably get some funky phasing effect.
jrazz wrote on 9/6/2006, 6:14 AM
If I remove the Levels and HSL Adjust, the pixelated vertical bars are visible at a minimal and to see them, you really have to look hard.

I would like to keep the color and tone that I adjusted to but without the pixelated bar effect. Any ideas? Glenn, I also tried the color correction saturation and it did not resolve the issue.

Bobb,
I will give it a go tonight once I get back to the office. Thanks for the input guys.

j razz
farss wrote on 9/6/2006, 6:44 AM
I saw something very similar to that yesterday. HDV sourced footage converted to SD. My mission was to convert it to a NTSC DVD and the very bright reds ended up with that same effect where there was shart transitions between the red and other colors, worst on a surfboard from memory.

I didn't spend much time analysing the issue as it was a very rush job, could well have also been in the PAL source. I suspect your issue might be starting in the source and the CC is making it more apparent or is it the cameras downsampling?
MarkFoley wrote on 9/6/2006, 6:57 AM
Red and Video do not make good pals...I cringe every wedding I do when I find out the dresses will be red. I have found that any adjusting of contrast in post tends to make reds fall apart...especially if the original material was shot in less than ideal lighting conditions....
jrazz wrote on 9/6/2006, 7:20 AM
Well, I know that it is not the HD footage as the JVC footage does it to. The angle that is showing the girl walking down the isle-way from behind is the JVC standard Def Cam. So, I assume that the adjustments I made to the colors, etc (especially since it is almost a non-issue without the adjustments) are the culprit. But, if they cause this problem- why are they there? Maybe it is the way my particular footage interacts with the adjustments I made.

j razz
GlennChan wrote on 9/6/2006, 12:01 PM
If going from DV to DVD, you could try adding the chroma blur filter. NTSC DV is 4:1:1 color sampling, so chroma blur of 2.0 pixels horizontally should be appropriate I believe.

That's assuming this is a problem with chroma subsampling (i.e. recording in 4:1:1)... it tends to create artifacts where there are chroma transitions. This is made worse if the signal is not being treated properly... i.e. filtering the camera, filtering in your compressors, and chroma interpolation in your decoders.
farss wrote on 9/6/2006, 4:38 PM
Just to go one step back here.

I know you say it's almost a non problem in the source but clearly bumping something up is going to accenuate anything wrong in the first place.

How did the JVC footage become 16:9, I thought at first you were using the JVC 700 camera but I don't see anything like that in the shots, looks like you were using a 4:3 camera in '16:9', might that not account for where the gremlins got in in the first place?

As Glenn says though some chroma blur should help.
jrazz wrote on 9/6/2006, 6:30 PM
I thought at first you were using the JVC 700 camera
I was using a JVC JY-VS200U, which is a 4:3 that was shot in letterbox and the A1's were downconverted to letterbox to match. Same as the other thread I posted a while back that you responded to Bob.

But as for the chroma blur, I bumped it up and it fixed it on the monitor and a small clip I rendered out. So, I am in the process of rendering it out. Thanks for the bit of knowledge Glenn- it was well served.

Bob, concerning the audio, I got it. For some reason it was dropping the frame while playing in one of my A1's- the one that did not film it. When I popped it back in the one that captured it, I was able to recapture and plug it back in. I don't understand that, but what clued me in on this is I tried to play back my tapes captured in the A1's on the HDR-HC1 I purchased and all it shows is a blue screen. I tried auto, HDV and being out of options, tried DV and none allowed for playback of the A1 captured tapes. I thought maybe I could use the cheaper camera to capture from and play from, but it is a no go.

Again, thanks for your help on this.

j razz