[Comparison mp4-mxf] Quality of reds in CS4 at DVinfo.net

Markus Klatt · July 4th, 2009, 01:35 AM

I just noticed that reds from EX1 look different in PP CS4 depending if they are native mp4 or rewrapped mxf from ClipBrowser 2.5 on windows.

See the example frame. The red lights, especially on the left side, have a stripy, rasterized aura in mxf. This was one of my very first shots with EX1 several months ago, shot in HQ 720/50p. When you load them into a picture viewer like IrfanView and switch back and forth you see the difference - its the same effect one can notice in CS4 timeline directly. So it should not be a problem in IrfanView.

Is this "just" a problem of CS4 in timeline and when exporting TIFFs in AME? Or is this really a difference in mp4 and mxf? Since it is just a container rewrapping I would not expect any difference.
One will not notice this effect in blues, greens, yellows or any other colors - just intense reds. Probably a traffic light would be a good object to try...
I could not judge if it can be seen when playing the mxf as video in VLC, its just to fast movement.

Tim Polster · July 4th, 2009, 12:41 PM

Markus,

I am seeing the same thing, but in Edius.

I have noticed horizontal banding only on the red areas as well.

I new something was wrong but thought it was the compression and it was not that noticeable when playing in realtime.

But now that you post this comparison I realized that I was using MXF files converted in Clip Browser.

This looks like a bug in Clip Browser and how it converts to MXF.

Sony needs to be consulted about this.

David C. Williams · July 4th, 2009, 04:39 PM

I'd think there's more likely an issue with how the data is decoded by CS4. Clipbrowser does not change the data at all, just the container. It stays mpeg2, 99.9% of the file stays exactly the same between mp4 and mxf.

Tim Polster · July 4th, 2009, 06:25 PM

I don't have the time right now, but I will check the file I noticed this in.

I will import the Mpeg and the mxf to see if there is a difference in Edius.

July 4th, 2009, 01:35 AM	#1
Markus Klatt Regular Crew Join Date: Jul 2004 Location: Berlin, Germany Posts: 169	[Comparison mp4-mxf] Quality of reds in CS4 I just noticed that reds from EX1 look different in PP CS4 depending if they are native mp4 or rewrapped mxf from ClipBrowser 2.5 on windows. See the example frame. The red lights, especially on the left side, have a stripy, rasterized aura in mxf. This was one of my very first shots with EX1 several months ago, shot in HQ 720/50p. When you load them into a picture viewer like IrfanView and switch back and forth you see the difference - its the same effect one can notice in CS4 timeline directly. So it should not be a problem in IrfanView. Is this "just" a problem of CS4 in timeline and when exporting TIFFs in AME? Or is this really a difference in mp4 and mxf? Since it is just a container rewrapping I would not expect any difference. One will not notice this effect in blues, greens, yellows or any other colors - just intense reds. Probably a traffic light would be a good object to try... I could not judge if it can be seen when playing the mxf as video in VLC, its just to fast movement. Attached Thumbnails Last edited by Markus Klatt; July 4th, 2009 at 05:03 AM.

July 4th, 2009, 04:39 PM	#3
David C. Williams Major Player Join Date: Jun 2008 Location: melb.vic.au Posts: 447	I'd think there's more likely an issue with how the data is decoded by CS4. Clipbrowser does not change the data at all, just the container. It stays mpeg2, 99.9% of the file stays exactly the same between mp4 and mxf. __________________ www.davidwilliams.com.au

July 4th, 2009, 12:41 PM	#2
Tim Polster Inner Circle Join Date: Dec 2004 Location: Arlington, TX Posts: 2,231	Markus, I am seeing the same thing, but in Edius. I have noticed horizontal banding only on the red areas as well. I new something was wrong but thought it was the compression and it was not that noticeable when playing in realtime. But now that you post this comparison I realized that I was using MXF files converted in Clip Browser. This looks like a bug in Clip Browser and how it converts to MXF. Sony needs to be consulted about this.

July 4th, 2009, 06:25 PM	#4
Tim Polster Inner Circle Join Date: Dec 2004 Location: Arlington, TX Posts: 2,231	I don't have the time right now, but I will check the file I noticed this in. I will import the Mpeg and the mxf to see if there is a difference in Edius.