Any fix for the H.264/QT gamma bug?

Delivering some color-critical work for the web this week, and the whole H.264/QT7/QTX gamma bug is really biting me in the ass. It doesn't help that my client is on PC and I don't have an easy way of knowing what they're seeing when they view these (plus they're getting re-encoded to Flash on the back end). I've gone back through previous posts and I've seen the complaints, just wondering if there are any new solutions that have come up in the last few months. Are you guys using x264, custom gamma correction, etc.?

Also wondering if any of this mess has been resolved with Lion and/or FCPX, with the new Colorsync workflow. Anyone tried tests with H.264 output with the new OS yet?

(My project: FCP7, Canon 7D files output to ProRes SCQT, converted to H.264 640x360 via Compressor and custom Matrox 2 preset)

TIA,

JVK

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SCQT! Self-contained QuickTime ? pass it on!

Can you actually deliver colour critical to the web? Go stand in any computer store and look at all the monitors at once - no two brands or models are the same, and there are multiple set-up options. As you say, PCs are darker than Macs, so how do you get a correct reference?

Hi Jude,

I doubt there can ever be a TRUE reference for web-only work, but I at least try to start from the best possible setup. Good monitor with decent specs, calibrated with a colorimeter and set to the same gamma settings as the client. Now that Macs have finally switched over to 2.2 I'm hoping that there will be some amount of parity across the various PCs and monitors, but yeah there are a lot of variables.

In my case though, I say "color critical" because from day 1 our client has been complaining that the footage has a certain tint to it even though we can't see it on our end. We kept telling them it was their equipment, that our systems were calibrated, etc. etc. Then I took a closer look at our outputs and saw the prominent gamma shift happening in the H.264 files, so it wasn't a huge stretch to think that after converting to Flash for their site and viewing it on a PC that it would look like ass. It's so frustrating to get an image looking good on both an external monitor and the Viewer on my Cinema Display (figuring the truth is somewhere in between) only to have the H.264 process come in and wreck everything. Grrrrr....

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SCQT! Self-contained QuickTime ? pass it on!

I agree. It's frustrating all over. Could you deliberately slant the footage to the opposite hue so that it's basically neutralised at the client end? I realise that's a terribly inaccurate offering, but I have no workaround for the bug myself, which is not to say there isn't one.

The color managed workflow in FCP X has eliminated color shift problems in the exports I've done so far. At least as far as the image remaining the same color and luminance throughout the process. That says nothing of what happens on other people's monitors though.

FCP X might be a good solution for web-only workflows.

Andy

Truth is, the 1.8 gamma that Apple applies is a viewing LUT. It should not affect the encoded signal. But of course, when you transcode stuff via QT and import that into Avid, you get a gamma shift, which shouldn't at all be applied.



www.strypesinpost.com

When you say "converting to Flash", do you mean re-encoding the file? If so, why not supply them with a ProRes movie?

My software:
Pro Maintenance Tools - Tools to keep Final Cut Studio, Final Cut Pro X, Avid Media Composer and Adobe Premiere Pro running smoothly and fix problems when they arise
Pro Media Tools - Edit QuickTime chapters and metadata, detect gamma shifts, edit markers, watch renders and more
More tools...

Jon Chappell Wrote:
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> When you say "converting to Flash", do you mean
> re-encoding the file? If so, why not supply them
> with a ProRes movie?


I'd like to, but they've always just converted from the H.264s I give them. Definitely will bring it up for the next round!

And FWIW, the gamma shift is the most apparent when content is converted to SD. H.264s that stay in the HD color space are a lot closer to the original file in my tests. Also, mp4s come out better at SD sizes too.

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SCQT! Self-contained QuickTime ? pass it on!

Try toggling the color encoding settings in Compressor.



www.strypesinpost.com

strypes Wrote:
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> Try toggling the color encoding settings in
> Compressor.


Ah-ha. You mean the 'Color' tab in the Filters section, right? I've never dug around in there!

? Default for encoder
? Preserve source
? SD (601)
? HD (709)

Interesting. I'll try to run some tests next week, see what happens if choose other options besides 'default'. Thanks man!

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SCQT! Self-contained QuickTime ? pass it on!