Gamma Shift Prob (Exporting DVCpro Timeline to H264)

[Dustin Parsons]

Well… it’s actually not working that well. Like I said, I can’t go to FLV from the x.264 without the color/gamma shifting back as well as getting corrupted pixels in various places – this also happens when I watch it using Finder’s Quicklook. Because of these issues I’m afraid to use x.264 for delivering to clients, it just seems very unstable.

I thought I could get around these issues by exporting the x.246 to Apple ProRes – this seemed to work (no color/gamma shift from the x.264) but I can’t deliver a 4.5Gb file for previewing purposes so I then tried exporting the ProRes file to an H.264 aaaaaand we’re back to square one. The H.264 shifted the colors/gamma back to the muted greenish tint as if I had just exported it straight out of Final Cut.

This is very frustrating. Has anyone else played around with this anymore?

I guess my one and only question is: is there any possible way I can have an actual H.264 movie (not x.264) that displays the same color/gamma in QuickTime as it does Final Cut without it mattering whether I have Enable Final Cut Studio Compatibility checked in the QuickTime preferences?

I’m going to continue trying to figure it out myself but any and all suggestions are greatly appreciated. Thanks!

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Mac Pro | Leopard 10.5.7
2.66GHz Dual-Core Intel Xeon | 4GB Ram
Final Cut Pro Studio 2 | Avid Media Composer

[Matt Lyon]

Dustin, there are other software encoders that people have reported getting good results with, like “Episode” and “CompressHD” … try searching the forum.

I have found x264 to be a little kludgy, but once I found the right settings, I am getting consistent results as far as gamma is concerned.

But why are you encoding ProRes movies from your x264 quicktimes? You are just creating pointless generation loss. You should export ProRes quicktimes directly from your original timeline, or from a native, self-contained or reference quicktime, using Compressor.

And I don’t have much experience with FLV, but my understanding was you don’t need to use that format if you are delivering h264 compliant streams (they work natively in Flash).

Matt Lyon
Editor
Toronto

[Matt Lyon]

Hey all,

A poster on another thread linked to this article about FCP’s assumptions about system gamma:

https://support.apple.com/kb/HT2912

I can confirm that this is definitely true of FCP v1-6, but I haven’t used FCP 7 enough to confirm or deny (this article predates FCP 7).

So the point is, if your monitor(s) are calibrated to 2.2, then images will be displayed in the FCP windows with too high a gamma (too saturated and contrasty).

But once you export an H264 quicktime, I would still think it seems best to view under 2.2 gamma settings, to more closely approximate what PC users see.

A bit of a PITA, eh? I’m hoping to do some more exhaustive tests soon!

Matt Lyon
Editor
Toronto

[Chris Hart]

Gamma Shift in h264 from fcp.

One way to make your h264 quicktimes on the desktop match the way your timeline looks in fcp:

When exporting to h264, use Compressor, and use a couple filters. A 1.1 gamma filter adjustment, along with a .7 contrast adjustment, helped my last sequence look the same in fcp and in the h264 qt. The qt looked the same on Daily Motion, too. Not sure about youtube yet.

I found this info on another forum, passing it along.

Good luck.

[Chris Hart]

Correction, sorry. The contrast adjustment is 7 out of 100 in the Brightness and Contrast Compressor filter.

Extremism in the pursuit of good edges on the foreground object is no vice.

[Gabriel Weigl]

Hi Matt,

I would like to reply your post. I did full HD sequence in apple prores 422 HQ, graded in Color, using JVC pro grading monitor DT-V17G1Z with gamma set to 2.2. Secound monitor Samsung SyncMaster T240 is set to match JVC DT-V17G1Z as close as it can. I did edit some years in Avid but that doesnt matter now. I got problems to get good DVD export from FCP even Compressor coz of saturation failure. And yes I tried a lot but for me as profesional is not acceptable to make 10 random export from COLOR to match 1 DVD export. My question is what would THE profesionals from FCP or Apple COLOR advice whats THE WORKFLOW TO FINALIZE PROFESIONAL DVD? Doesnt matter what aplication to use just tell me how 🙂 Thanks.

[Gabriel Weigl]

Sorry folks,
Im new here and jumped some posts. I see now, will try Chris advices.
Thanks

[Matt Lyon]

Gabriel, how have you connected your JVC panel? Is it being driven by a proper video breakout box, like an AJA or Decklink with a YUV connection? This issue is a very common one on this forum. If you aren’t viewing your material on a proper Video monitor, with the correct signal path, then you aren’t viewing a correct image.

Also, don’t worry too much about matching your Samsung to your JVC monitor. The JVC monitor, when properly connected and calibrated, should be your hero monitor, and all color decisions based on what you see on that screen.

If you are grading your images on a computer display (or a Video Display connected to the graphics card of your Mac), then more often then not the saturation is artificially boosted. This appears subjectively nice, but isn’t necessarily an accurate representation of how your material will look in a calibrated video signal path.

Your final DVD should be evaluated on a good hardware DVD player (with all special video “enhancement” modes turned off), connected to the same JVC monitor (not on a computer screen). If you still see differences between your color grade and your output DVD, then you now have a solid basis for making adjustments.

Matt Lyon
Editor
Toronto

[Gabriel Weigl]

Hi,

JVC is conected through blacmagic intensity pro HDMI output. Thank you for good tip to verify DVD, yes its logical. But another question, if I do a DVD I would appreciate that it looks good +- on each display, not just on JVC.

OK, im gonna try
thanks

[Matt Lyon]

[Gabriel Weigl] “if I do a DVD I would appreciate that it looks good +- on each display, not just on JVC.”

I think everyone would agree with your sentiments, but there’s a reason that NTSC is said to stand for “Never The Same Color” (and PAL is Pretty AwfuL )

At the end of the day, once your show goes out the door, it is going to be watch on all sorts of poorly calibrated display systems. You can drive yourself crazy worrying about color.

But all this being said, when making a web only quicktime of your project, your DVD grade might need some tweaking. You can play with your compressor settings, as others on the thread have suggested. Then you can start driving yourself nuts thinking about display gamma on different operating systems and software 🙂

Matt Lyon
Editor
Toronto