Color & Contrast has changed during web compression of reel. Why? (XDCAM to H.264) at DVinfo.net

Matt Irwin · February 9th, 2008, 07:16 PM

Hi,

I am trying to compress a copy of a film I shot for viewing on my website as a showreel piece.

Upon compression, the image transforms from nice colors & good blacks to washed out /skewed color & milky shadows-- absolutely unusable for my purposes. Could anyone shed some light on the problem?

The project was shot on film and TK'd to D5, and the quicktime file I was given (and starting with) was compressed in "XDCAM HD 1080p/24 (35Mb/s VBR)."

I am exporting in FCP 5.1.2 using Quicktime Conversion:
Compression= H.264
Quality= High
Frame reordering= yes
Encoding Mode= multi-pass
Prepare for Internet Streaming= yes - Fast Start

Attached is a screen capture of the before and after. Left-side image is the original (good), right-side image is after export (bad).

Any help would be appreciated.
Thanks,
MI

Nick Weeks · February 11th, 2008, 07:27 PM

I think its just the H.264 codec, I've had the same problems with stuff from the XH-A1. I usually try and compensate some by setting brightness -5 and contrast +3 in the compressor output settings (same spot where you set watermark, de-interlace, etc... can't remember the name at the moment). It seems to help blacks for the most part, but the colors are still skewed

Matt Irwin · February 11th, 2008, 08:31 PM

Yes, it seems to be both the H.264 codec as well as QT player and Safari. After some more testing and asking around, I found a fix to the problem (not sure if this is universal, but it worked for me):

In Quicktime Pro--
-Open clip
-Window menu > Show Movie Properties
-Select "Video Track", then click "Visual Settings"
-Change Transparency (drop-down menu) value to "Composition."
-Save clip

This brought both the color and gamma back to normal.

What's strange is that the initial export (bad gamma) looks completely normal when viewed in Firefox.... and so does the fixed version! No difference at all.. but in Safari and QT Player it's like night and day.

Nick Weeks · February 23rd, 2008, 12:18 AM

Matt, you're tha man! That works perfect, fixes that terrible color problem on both windows and mac playback. Only downside, it seems to make playback a little choppy, both on my PC and Mac, more so than the standard setting.

Why isn't that setting configurable in compressor? Seems like a viable option to me...

Charles Papert · February 23rd, 2008, 12:46 AM

I believe that is a function of Quicktime, both within the app itself and how it plays in Safari, that alters the gamma and apparent color saturation. Hopefully that will be fixed in a future version.

February 9th, 2008, 07:16 PM	#1
Matt Irwin Major Player Join Date: Jul 2004 Location: Los Angeles, CA Posts: 327	Color & Contrast has changed during web compression of reel. Why? (XDCAM to H.264) Hi, I am trying to compress a copy of a film I shot for viewing on my website as a showreel piece. Upon compression, the image transforms from nice colors & good blacks to washed out /skewed color & milky shadows-- absolutely unusable for my purposes. Could anyone shed some light on the problem? The project was shot on film and TK'd to D5, and the quicktime file I was given (and starting with) was compressed in "XDCAM HD 1080p/24 (35Mb/s VBR)." I am exporting in FCP 5.1.2 using Quicktime Conversion: Compression= H.264 Quality= High Frame reordering= yes Encoding Mode= multi-pass Prepare for Internet Streaming= yes - Fast Start Attached is a screen capture of the before and after. Left-side image is the original (good), right-side image is after export (bad). Any help would be appreciated. Thanks, MI Attached Thumbnails __________________ Matt Irwin DP / matt.irwincine.com

February 11th, 2008, 08:31 PM	#3
Matt Irwin Major Player Join Date: Jul 2004 Location: Los Angeles, CA Posts: 327	Yes, it seems to be both the H.264 codec as well as QT player and Safari. After some more testing and asking around, I found a fix to the problem (not sure if this is universal, but it worked for me): In Quicktime Pro-- -Open clip -Window menu > Show Movie Properties -Select "Video Track", then click "Visual Settings" -Change Transparency (drop-down menu) value to "Composition." -Save clip This brought both the color and gamma back to normal. What's strange is that the initial export (bad gamma) looks completely normal when viewed in Firefox.... and so does the fixed version! No difference at all.. but in Safari and QT Player it's like night and day. __________________ Matt Irwin DP / matt.irwincine.com

February 23rd, 2008, 12:46 AM	#5
Charles Papert Wrangler Join Date: Jan 2002 Location: Los Angeles, CA Posts: 6,810	I believe that is a function of Quicktime, both within the app itself and how it plays in Safari, that alters the gamma and apparent color saturation. Hopefully that will be fixed in a future version. __________________ Charles Papert www.charlespapert.com

February 11th, 2008, 07:27 PM	#2
Nick Weeks Major Player Join Date: Jan 2006 Location: Birmingham, AL USA Posts: 722	I think its just the H.264 codec, I've had the same problems with stuff from the XH-A1. I usually try and compensate some by setting brightness -5 and contrast +3 in the compressor output settings (same spot where you set watermark, de-interlace, etc... can't remember the name at the moment). It seems to help blacks for the most part, but the colors are still skewed

February 23rd, 2008, 12:18 AM	#4
Nick Weeks Major Player Join Date: Jan 2006 Location: Birmingham, AL USA Posts: 722	Matt, you're tha man! That works perfect, fixes that terrible color problem on both windows and mac playback. Only downside, it seems to make playback a little choppy, both on my PC and Mac, more so than the standard setting. Why isn't that setting configurable in compressor? Seems like a viable option to me...