Vegas 7.0b Sony MXF export alters the colors at DVinfo.net

Hornady Setiawan · November 17th, 2006, 07:43 AM

I'm trying out Vegas 7.0b.

I put some hi-res still photos and keyframe some motion to them.

Then i render as Sony MXF 35Mbps / 25p.

I drag the resulting MXF into timeline, and notice the color is different than the original!! Oranges becomes more red, greens become more bluishgreen...

I tried exporting to Quicktime Avid DV100, the colors are same as orig, no problem.

It seems Vegas's MXF export alter the LUT or something?
Anyone seen this?

Greg Boston · November 17th, 2006, 09:50 AM

Hornady, this may be similar behavior to FCP. It alters the gamma differently depending on what it thinks you're working with. Try using a video clip and doing the same thing to see if it gets altered.

-gb-

Here's a snippet from Apple's website, take note of the last sentence.

Quote:

What causes this?
Final Cut Pro assumes that QuickTime movies for codecs that support the YUV color space (including DV, DVCPRO 50, and the 8- and 10-bit Uncompressed 4:2:2 codecs) are created with a gamma of 2.2. This is generally true of movies captured from both NTSC and PAL sources. When you eventually output the sequence to video, or render it as a QuickTime movie, the gamma of the output is identical to that of the original, unless you've added color correction filters of your own.

However, during playback on your computer's monitor, Final Cut Pro automatically lowers the gamma of a sequence playing in the Canvas to 1.8 for display purposes. This is to approximate the way it will look when displayed on a broadcast monitor. This onscreen compensation does not change the actual gamma of the clips in your sequence.

RGB Image Files and Sequences Issue
When importing a still image file or sequence from Shake into Final Cut Pro, the gamma may be incorrectly boosted when the sequence is output to video or rendered as a QuickTime movie.

Simon Wyndham · November 17th, 2006, 05:13 PM

Hornady, I have just run a test and you are indeed correct. I'll investigate right away.

Hornady Setiawan · November 18th, 2006, 07:58 AM

Greg - thanks for your info. What i see is not really altered gamma. Gamma is almost the same, only colors change a bit.
It seems most likely that Vegas is handling color LUT wrongly? Like a wrong handling of BT.709 to BT.601 conversion?

Simon - if you grab an mxf clip from your camera into vegas, then re-render it into a new mxf file, then put the new mxf back into XDcam disc, then playback both file (original and re-rendered), do you see difference in camera or in broadcast monitor? If yes, then this is a major color issue for vegas workflow...

thanks,
hornady.

Greg Boston · November 18th, 2006, 08:15 AM

Quote:

Originally Posted by Hornady Setiawan

Greg - thanks for your info. What i see is not really altered gamma. Gamma is almost the same, only colors change a bit.
It seems most likely that Vegas is handling color LUT wrongly? Like a wrong handling of BT.709 to BT.601 conversion?

Ok, thanks for the clarification on that. Not being a Vegas user, I'll defer to Simon and see what he comes up with.

Hope you get it figured out very soon.

-gb-

Simon Wyndham · November 19th, 2006, 01:12 PM

Hmm, this is a difficult one.

Hornady Setiawan · November 19th, 2006, 09:40 PM

OK, don't say anything, just nod your head...
OK i got it...! Vegas 7.0c will be coming out sooner! Yeah! :)

Uli Mors · November 20th, 2006, 05:05 AM

I´ve seen color shifts with DV Avi files before as well (in Vegas):

I filmed a concert sequence where we used a very cool flood light (VERY blueish). I captured with scenalyer.

Playback in Vegas was fine UNTIL ANY rendering or filter (even 0% filter effect) came into play. Color Space looked somehow cut.

I compared playback of these Avi files with EDIUS thru a STORM2 Card - fine, even with filters.

Comparing vectorscopes I found that my (PANA DVC200 DV) files exceded heavily the BLUE Signal, no problem in Edius, but a big problem in Vegas.

Vegas did cut all colours (B) to a certain maximum - resulting in a less rich / colourful picture.

As a workaround I desaturated all clips in Edius to ~ 60%, editied in Vegas and pushed colours back later in a mastering step in Edius again.

Finally, Vegas RGB colourspace seems to be smaller than my DV recordings...

Probably you deal with the same problem?

ULI

Hornady Setiawan · November 20th, 2006, 08:55 PM

Uli - thanks, altho i havent tried/seen in SD formats, yours maybe same case. BTW, what's your Vegas version?

Uli Mors · November 21st, 2006, 03:47 AM

Well, I encountered this in Vegas 6.

I just checked with Vegas 7 (b) - yep , it DOES change the saturation (but I think it cuts BLUE only in my case)

I uploaded a small piece (26mb) - its just a small clip with fade. Just look the BLUE colour changing with the first frame of the dissolve. Blue Sat totally dies, overall impression changes (since the strong blue dominates the background).

http://www.media-in-work.de/fuer_vvf...u_hartmann.zip

You can use ANY procession (filter to Zero etc.) - the colour space is reduced instantly.

I wonder, because I thought miniDV (this was a DV clip from Panasonic DVC200) is the same colorspace like Vegas.

?

ULI

William Hess · November 21st, 2006, 03:16 PM

I've experienced this issue before in Vegas 6 and 7, with highly saturated (possibly over saturated) footage.

Part of the reason this happens is because the Vegas rendering pipeline and filters only work with RGB, so any YUV footage has to be converted to the RGB color space. However, the colorspaces are quite different, and I know for a fact that there are certain color values in YUV which cannot be converted to RGB.

Usually the conversion is unnoticeable, however certain highly saturated clips can be substantially affected by this colorspace conversion.

Most other editing programs (including Edius, Liquid, Premiere Pro, Final Cut) can work natively in the YUV color space, therefore eliminating some color space conversion issues.

When dealing with HD there's also the whole BT.709 to BT.601 issue, however this was supposed to be fixed in Vegas 7.

Uli Mors · November 21st, 2006, 06:23 PM

Quote:

Originally Posted by William Hess

When dealing with HD there's also the whole BT.709 to BT.601 issue, however this was supposed to be fixed in Vegas 7.

Hi ,

I am not too much expert with this...

Would that mean : If I use XDCAM HD and get into "corners" of YUV recording (e.g. fat saturated colours) I will probably encounter the same problem?

And : Even if I use a YUV NLE - how does mpg (DVD) behaves?

Thanks

ULI

Hornady Setiawan · November 25th, 2006, 09:45 PM

i thought there are loss of color range / gamut when RGB convert to YUV ... but not the other way around? Isn't RGB has the widest possible colors in digital conversion? (since RGB is the real primary colors)

what i did test was using hiquality jpegs from digital camera, render them into XDCAM mpeg2 .mxf

i'll post my footage later on when i'm free...

Hornady Setiawan · December 1st, 2006, 12:36 PM

notice the green t-shirt at upper left
notice the reds at lower right

you'll have to download the full sized image. Color difference in small-scaled image here are not very evident.

these are hi-q jpegs.

Simon Wyndham · December 11th, 2006, 09:25 AM

Vegas 7c free update has now been released which fixes this colour shift problem.

November 17th, 2006, 07:43 AM	#1
Hornady Setiawan Regular Crew Join Date: May 2005 Location: Jakarta, Indonesia Posts: 103	Vegas 7.0b Sony MXF export alters the colors I'm trying out Vegas 7.0b. I put some hi-res still photos and keyframe some motion to them. Then i render as Sony MXF 35Mbps / 25p. I drag the resulting MXF into timeline, and notice the color is different than the original!! Oranges becomes more red, greens become more bluishgreen... I tried exporting to Quicktime Avid DV100, the colors are same as orig, no problem. It seems Vegas's MXF export alter the LUT or something? Anyone seen this?

November 19th, 2006, 01:12 PM	#6
Simon Wyndham Trustee Join Date: Dec 2003 Location: Malvern UK Posts: 1,931	Hmm, this is a difficult one. Last edited by Simon Wyndham; November 20th, 2006 at 05:26 AM.

November 21st, 2006, 03:47 AM	#10
Uli Mors Major Player Join Date: May 2006 Location: Germany Posts: 565	Well, I encountered this in Vegas 6. I just checked with Vegas 7 (b) - yep , it DOES change the saturation (but I think it cuts BLUE only in my case) I uploaded a small piece (26mb) - its just a small clip with fade. Just look the BLUE colour changing with the first frame of the dissolve. Blue Sat totally dies, overall impression changes (since the strong blue dominates the background). http://www.media-in-work.de/fuer_vvf...u_hartmann.zip You can use ANY procession (filter to Zero etc.) - the colour space is reduced instantly. I wonder, because I thought miniDV (this was a DV clip from Panasonic DVC200) is the same colorspace like Vegas. ? ULI Last edited by Uli Mors; November 21st, 2006 at 05:18 AM.

December 1st, 2006, 12:36 PM	#14
Hornady Setiawan Regular Crew Join Date: May 2005 Location: Jakarta, Indonesia Posts: 103	notice the green t-shirt at upper left notice the reds at lower right you'll have to download the full sized image. Color difference in small-scaled image here are not very evident. these are hi-q jpegs. Attached Thumbnails

November 17th, 2006, 05:13 PM	#3
Simon Wyndham Trustee Join Date: Dec 2003 Location: Malvern UK Posts: 1,931	Hornady, I have just run a test and you are indeed correct. I'll investigate right away.

November 18th, 2006, 07:58 AM	#4
Hornady Setiawan Regular Crew Join Date: May 2005 Location: Jakarta, Indonesia Posts: 103	Greg - thanks for your info. What i see is not really altered gamma. Gamma is almost the same, only colors change a bit. It seems most likely that Vegas is handling color LUT wrongly? Like a wrong handling of BT.709 to BT.601 conversion? Simon - if you grab an mxf clip from your camera into vegas, then re-render it into a new mxf file, then put the new mxf back into XDcam disc, then playback both file (original and re-rendered), do you see difference in camera or in broadcast monitor? If yes, then this is a major color issue for vegas workflow... thanks, hornady.

November 19th, 2006, 09:40 PM	#7
Hornady Setiawan Regular Crew Join Date: May 2005 Location: Jakarta, Indonesia Posts: 103	OK, don't say anything, just nod your head... OK i got it...! Vegas 7.0c will be coming out sooner! Yeah! :)

November 20th, 2006, 05:05 AM	#8
Uli Mors Major Player Join Date: May 2006 Location: Germany Posts: 565	I´ve seen color shifts with DV Avi files before as well (in Vegas): I filmed a concert sequence where we used a very cool flood light (VERY blueish). I captured with scenalyer. Playback in Vegas was fine UNTIL ANY rendering or filter (even 0% filter effect) came into play. Color Space looked somehow cut. I compared playback of these Avi files with EDIUS thru a STORM2 Card - fine, even with filters. Comparing vectorscopes I found that my (PANA DVC200 DV) files exceded heavily the BLUE Signal, no problem in Edius, but a big problem in Vegas. Vegas did cut all colours (B) to a certain maximum - resulting in a less rich / colourful picture. As a workaround I desaturated all clips in Edius to ~ 60%, editied in Vegas and pushed colours back later in a mastering step in Edius again. Finally, Vegas RGB colourspace seems to be smaller than my DV recordings... Probably you deal with the same problem? ULI

November 20th, 2006, 08:55 PM	#9
Hornady Setiawan Regular Crew Join Date: May 2005 Location: Jakarta, Indonesia Posts: 103	Uli - thanks, altho i havent tried/seen in SD formats, yours maybe same case. BTW, what's your Vegas version?

November 21st, 2006, 03:16 PM	#11
William Hess New Boot Join Date: Feb 2006 Posts: 20	I've experienced this issue before in Vegas 6 and 7, with highly saturated (possibly over saturated) footage. Part of the reason this happens is because the Vegas rendering pipeline and filters only work with RGB, so any YUV footage has to be converted to the RGB color space. However, the colorspaces are quite different, and I know for a fact that there are certain color values in YUV which cannot be converted to RGB. Usually the conversion is unnoticeable, however certain highly saturated clips can be substantially affected by this colorspace conversion. Most other editing programs (including Edius, Liquid, Premiere Pro, Final Cut) can work natively in the YUV color space, therefore eliminating some color space conversion issues. When dealing with HD there's also the whole BT.709 to BT.601 issue, however this was supposed to be fixed in Vegas 7.

November 25th, 2006, 09:45 PM	#13
Hornady Setiawan Regular Crew Join Date: May 2005 Location: Jakarta, Indonesia Posts: 103	i thought there are loss of color range / gamut when RGB convert to YUV ... but not the other way around? Isn't RGB has the widest possible colors in digital conversion? (since RGB is the real primary colors) what i did test was using hiquality jpegs from digital camera, render them into XDCAM mpeg2 .mxf i'll post my footage later on when i'm free...

December 11th, 2006, 09:25 AM	#15
Simon Wyndham Trustee Join Date: Dec 2003 Location: Malvern UK Posts: 1,931	Vegas 7c free update has now been released which fixes this colour shift problem.