Pixlet better than expected? at DVinfo.net

Christopher C. Murphy · October 31st, 2003, 04:01 PM

Ok, I've been doing some playing around and this is what I have found.

I have some footage of regular NTSC DV stock footage. If I layer some text on it - it's obvious that it has jagged edges. It looked aliased (as opposed to anti-aliased). I'll export to Pixlet and play it back - it looks really smooth. Unlike when I save to the standard Quicktime codec.

Does Pixlet add something or calculate in such a way that it helps all footage? I'd like to hear from other people who have looked at this too. I'm using high quality footage on a Mac, but of course its always looked NTSC-like. However, I swear that when I export to Pixlet and playback - it looks much better - smooth and without the edging. It's similar to when I use Photoshop to add very slight Gaussien blur (after applying the NTSC color filter). It makes the image playback better on NTSC - no jumping and flickering. (I recommend this to everyone by the way - always tweak stills before displaying on television - otherwise your images look like crap.)

Any thoughts anyone??

Chris

Steve Mullen · October 31st, 2003, 05:26 PM

<<<-- Originally posted by Christopher C. Murphy : It's similar to when I use Photoshop to add very slight Gaussien blur (after applying the NTSC color filter). -->>>

Prior to compression very fine details are eliminated by a filter. You are seeing this filter in action.

Your experiment is telling us something about Pixlet.

Christopher C. Murphy · October 31st, 2003, 05:43 PM

Steve,

I just found out something not-so-good. Although, the overall image definately looks better when exporting NTSC footage with text - it also took the text that was suppose to come out of a white background and garbled it. However, it's interesting because the general look of the text is better. It was just this one short bit (about 1/2 sec.) that it looked garbled. The codec must have chocked on the little bit? In other words, it looks like it got confused when it encountered a fade-in. It garbled the text slightly before revealing it.

What does this mean? Obviously, we can't do this if we're sensitive of the minute details in text or whatever detail. However, I absolutely love the way it looks overall after exporting to Pixlet. There is no doubt that it does something to the footage. Is there a way to figure out exactly what it's doing?

Is there a white-paper available on Pixlet anywhere? I used to do tons of streaming video, so I know a bit about codecs etc. If Apple has some tech info anywhere at all - maybe we can figure out what Pixlet is all about. I know its not really a mystery, but I would like to know what is happening under the hood.

Chris

Steve Mullen · October 31st, 2003, 06:24 PM

I've searched for details -- and nothing.

You don't want a codec to make any visible changes.

Eric Bilodeau · November 3rd, 2003, 09:48 PM

I agree changes from the original footage should not happen but this codec is optimised for HD not HD witch does not use the same gamma I believe,and most certainly not the same resolution...

I have not yet tried Pixlet but as soon as my G5 arrives I will test drive Pixlet thoroughly for sure.

October 31st, 2003, 04:01 PM	#1
Christopher C. Murphy Trustee Join Date: Sep 2003 Location: Boston, MA Posts: 1,707	Pixlet better than expected? Ok, I've been doing some playing around and this is what I have found. I have some footage of regular NTSC DV stock footage. If I layer some text on it - it's obvious that it has jagged edges. It looked aliased (as opposed to anti-aliased). I'll export to Pixlet and play it back - it looks really smooth. Unlike when I save to the standard Quicktime codec. Does Pixlet add something or calculate in such a way that it helps all footage? I'd like to hear from other people who have looked at this too. I'm using high quality footage on a Mac, but of course its always looked NTSC-like. However, I swear that when I export to Pixlet and playback - it looks much better - smooth and without the edging. It's similar to when I use Photoshop to add very slight Gaussien blur (after applying the NTSC color filter). It makes the image playback better on NTSC - no jumping and flickering. (I recommend this to everyone by the way - always tweak stills before displaying on television - otherwise your images look like crap.) Any thoughts anyone?? Chris

October 31st, 2003, 05:26 PM	#2
Steve Mullen HDV Cinema Join Date: Feb 2003 Location: Las Vegas Posts: 4,007	Re: Pixlet better than expected? <<<-- Originally posted by Christopher C. Murphy : It's similar to when I use Photoshop to add very slight Gaussien blur (after applying the NTSC color filter). -->>> Prior to compression very fine details are eliminated by a filter. You are seeing this filter in action. Your experiment is telling us something about Pixlet. __________________ Switcher's Quick Guide to the Avid Media Composer >>> http://home.mindspring.com/~d-v-c

October 31st, 2003, 06:24 PM	#4
Steve Mullen HDV Cinema Join Date: Feb 2003 Location: Las Vegas Posts: 4,007	I've searched for details -- and nothing. You don't want a codec to make any visible changes. __________________ Switcher's Quick Guide to the Avid Media Composer >>> http://home.mindspring.com/~d-v-c

November 3rd, 2003, 09:48 PM	#5
Eric Bilodeau Major Player Join Date: Jun 2003 Location: Chicoutimi, Canada Posts: 334	I agree changes from the original footage should not happen but this codec is optimised for HD not HD witch does not use the same gamma I believe,and most certainly not the same resolution... I have not yet tried Pixlet but as soon as my G5 arrives I will test drive Pixlet thoroughly for sure. __________________ Eric Bilodeau video SFX,DOP ___________________ http://www.fictis.net info@fictis.net

October 31st, 2003, 05:43 PM	#3
Christopher C. Murphy Trustee Join Date: Sep 2003 Location: Boston, MA Posts: 1,707	Steve, I just found out something not-so-good. Although, the overall image definately looks better when exporting NTSC footage with text - it also took the text that was suppose to come out of a white background and garbled it. However, it's interesting because the general look of the text is better. It was just this one short bit (about 1/2 sec.) that it looked garbled. The codec must have chocked on the little bit? In other words, it looks like it got confused when it encountered a fade-in. It garbled the text slightly before revealing it. What does this mean? Obviously, we can't do this if we're sensitive of the minute details in text or whatever detail. However, I absolutely love the way it looks overall after exporting to Pixlet. There is no doubt that it does something to the footage. Is there a way to figure out exactly what it's doing? Is there a white-paper available on Pixlet anywhere? I used to do tons of streaming video, so I know a bit about codecs etc. If Apple has some tech info anywhere at all - maybe we can figure out what Pixlet is all about. I know its not really a mystery, but I would like to know what is happening under the hood. Chris