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When exporting my 10 bit project, why it shows 8 bit ...

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Anhtu Vu
When exporting my 10 bit project, why it shows 8 bit ...
on Jan 24, 2011 at 8:06:58 pm

1-I'm working in 10 bit ( 1920x1080_29.97 DF ) . In the Export Image window i chose QT and codec = RGB uncompressed, by dong so, the resize automatically shows 8 bit....why ??? Doesn't Smoke run internally at 10 bit ???

2-Is there a way to read a 10 bit uncompressed QT file on Win xp ( My blu ray authoring machine is on XP ) ???



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Hans von Sonntag
Re: When exporting my 10 bit project, why it shows 8 bit ...
on Jan 24, 2011 at 10:08:00 pm

"1-I'm working in 10 bit ( 1920x1080_29.97 DF ) . In the Export Image window i chose QT and codec = RGB uncompressed, by dong so, the resize automatically shows 8 bit....why ??? Doesn't Smoke run internally at 10 bit ???"

Please check on the Editdesk on the Record window wether your project is really 10 Bit. If so, it may be a QT issue that arises because Autodesk assumes that RBG is in FCP 8bit anyway and hence delivers QT RGB in 8-bit. Also it may be the case that the QT RGB codec in Smoke is 8-bit only and not available in 10bit. I assume the latter one is the case.

I don't use the RGB codec, I use the 10bit uncompressed 422 codec which is YUV. With any QT YUV codec this leads to gamma shifts. Fortunately Smoke has a gamma compensation tool in the Export module included that is made to deal with this infamous issue. If I recall correctly we use 1.2 gamma compensation to match the original pretty closely.

However, there are scenarios where a QT gamma shift is desired. If you export to QT uncompressed 422 10bit you get a more contrasty result. Form there a transcoding to h264 MOV leads to a result which matches the original gamma closely. In this case the gamma shift corrects the gamma shift....


"2-Is there a way to read a 10 bit uncompressed QT file on Win xp ( My blu ray authoring machine is on XP ) ???"

You can use QT uncompressed 422 YUV on windows very well (we do it all day) as a source for anything else. You may encounter funky gamma shifts. QT is even worse on Windows. Blame Apple. With Smoke's gamma tool in the export module you can tackle this. It needs some testing though.

Hope that helps,

Hans


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Anhtu Vu
Re: When exporting my 10 bit project, why it shows 8 bit ...
on Jan 25, 2011 at 1:09:50 am

If i remember correctly, QT on Windows only playback 8 bit uncompressed and not 10 bit. Canyou play 10 bit uncompressed file on your Win xp machine ???

the gamma shift, is this a playback issue ( therefore a QT problem ) or it's Smoke that output a faulty file ??? Thanks again.



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Anhtu Vu
Re: When exporting my 10 bit project, why it shows 8 bit ...
on Jan 25, 2011 at 2:51:05 am

Just testing different QT players, even on the same Mac, QT version 10 and 7 yielded different gamma on playback. It's basically all over the map.



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Hans von Sonntag
Re: When exporting my 10 bit project, why it shows 8 bit ...
on Jan 25, 2011 at 8:37:24 am

Welcome to the world of QT.

Besides the infamous QT gamma shifts all QT player play back only in 8bit even the file is 10bit. This means you see banding in a 10bit file played back in the QT player. The only way to evaluate the file correctly is to view it in a application like AE, Fusion, Shake, Nuke and of course Smoke.

Hans


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Hans von Sonntag
Re: When exporting my 10 bit project, why it shows 8 bit ...
on Jan 25, 2011 at 8:45:25 am

Something more to think about:

Most displays are 8bit, only a very few work natively in 10bit, and even then it still depends on how they are connected to the box. AFAIK, display port on Windows is the only way to connect a display in full 10bit except SDI, of course.

Some 8bit monitors show a better dithering to fight banding, others are less well working in this regard. The only way to view 10bit correctly is to view it in a 10bit environment: 10 bit display connected to a 10bit source and a application that is able to play back 10bit - not QT.

So you may find here an other obstacle.

Hans


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Anhtu Vu
Re: When exporting my 10 bit project, why it shows 8 bit ...
on Jan 25, 2011 at 9:09:44 pm

The way i check my work is to play it through the little Kona Player ( found in the Kona utility ). It plays directly through its card to your broadcast monitor.

My Movie played this way looked exactly the same on PC or Mac.

BTW Hans, are you using the Dreamcolor as your main reference monitor ??? How do you have it set up ???



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Hans von Sonntag
Re: When exporting my 10 bit project, why it shows 8 bit ...
on Jan 26, 2011 at 8:51:39 am

"The way i check my work is to play it through the little Kona Player ( found in the Kona utility ). It plays directly through its card to your broadcast monitor.

My Movie played this way looked exactly the same on PC or Mac."

No wonder. You bypass the QT wrapper when going through the Kona. It also shows that your Mac and your PC display are very similar set up.

Hans


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Hans von Sonntag
Re: When exporting my 10 bit project, why it shows 8 bit ...
on Jan 26, 2011 at 9:26:41 am

[Anhtu Vu] "BTW Hans, are you using the Dreamcolor as your main reference monitor ??? How do you have it set up ???"

No. I'm using Eizos. The Eizo on Smoke is set to Rec709 (basically sRGB and gamma 2.35) and connected via DVI to the Mac. We have an Sony Ruby VPL100 projector hooked to the Kona and sometimes an SD Sony BVM monitor when deliveries are PAL.

When evaluating a project via DVI please remember that for VUY in an 8bit system 0 = 16 and 255 = 235. This may lead to a more contrasty look on your SDI (Kona) display and later on tape than on your DVI display that hosts Smoke's interface. For projects that don't go to tape full gamut 0-255 is fine, hence your DVI display will do the job. For jobs that go to tape and later on air you want an SDI monitor.

Also there are some subtle colour differences in DVI and SDI due to the fact that DVI is RGB and SDI is YCbCr which needs a mathematical conversion.

There are possibilities in Smoke (LUTs) to cover this issue.

Hans


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Anhtu Vu
Re: When exporting my 10 bit project, why it shows 8 bit ...
on Jan 26, 2011 at 9:30:12 pm

Hans,

Which model Eizo do u have ??? Any reason why you chose this model over a dreamcolor ??? Thanks



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