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PPro can only play back at 8 bit
1. Create a 10bit-or-better gradient (or download the 16-bit TIFF ramp from here)
2. Put it in a Premiere timeline, and apply a filter to stretch the levels hard. I used the Fast Color Corrector and adjusted the Input Levels to 100, 1.0, 150.
3. Play it.Regardless of the settings, when you play or scrub you’ll see banding. When you sit still the image “snaps” into high-bit-depth and the banding disappears.
Fast Color Corrector works in 32bit and is GPU-accelerated. I set the Render preference to Memory instead of Performance, enabled Maximum Bit Depth & Maximum Render Quality in the sequence settings, and set playback quality to Full.
Seeing this in both CC and CC2014.
If you render the clip, the render runs at ≧10bit so the processing looks correct (I’m unable to tell if it renders and plays in ≧10bit correctly; processes in ≧10bit into an 8bit render file; or renders to a ≧10bit file but plays back at 8bit bit… because it’s visually indistinguishable and I don’t have the test equipment to measure).
I should also note that this is a “yellow” clip (with an effect). I can’t tell if a native ≧10bit clip (that doesn’t have any color render bar above it) plays at ≧10bit or 8bit – or in other words, if this behavior is limited to real-time processing of clips or applies to anything in a timeline.I’m using a Decklink Extreme 3D+, but it’s internal to Premiere (unrelated to Transmit or video I/O) since I’m seeing the same behavior with Transmit disabled, in the GUI program monitor.
Can you confirm this behavior? Is this known?
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7 Replies
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This might be important….mac or pc?
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Mac OS X 10.8.5 here.
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Some time back I recall reading about not getting more than 8-bit
output on macs…pc didn’t have the issue. Something about the SDI output
though I think.I wonder if its related.
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But this happens also without an SDI card or with it disabled; in theory it would even happen in a system without any monitor 🙂 My GUI monitors are connected via DVI so they’re 8 bit anyway.
This is about timeline processing. -
If your monitors are only 8bit, they will display banding no matter the resolution of the timeline. The monitors themselves will be the limit here.
You mention the Decklink 3D but do you have an actual 10bit monitor attached to your output? Without that, you’re going to see banding no matter what you do in the situations described. Send a 12 bit ramp to an 8 bit monitor and you’re going to see…. banding.
Walter Biscardi, Jr.
Editor, Colorist, Director, Writer, Consultant, Author, Chef.
HD Post and Production
Biscardi Creative MediaCraft and Career Advice & Training from real Working Creative Professionals
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Hi Walter, glad to have you aboard in this thread.
I do have a Decklink Extreme 3D+ running HD-SDI to a (calibrated) Sony BVM HD CRT w/ the BKM-142HD board, so I have a 10-bit signal path.. and an infinite-bit panel 😉But read what I described again, I narrowed the issue down to internal processing in PPro regardless of any video output. There’s banding during playback/scrubbing and no banding when paused – on the same frame and same monitoring chain. The banding comes and goes with a hit of the space bar.
It is possible that the thread title should have been “PPro can only render-on-the-fly at 8 bit”. That’s what I’m trying to figure out.
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Hi,
I came across this thread when I was having problems myself. PLease see my Adobe thread here:
https://forums.adobe.com/thread/2063442?sr=stream&ru=794883
The current state of play is that it looks like this issue is related to your sequence preset – in my case 10 bit DNX sequences only encode and ‘edit to tape’ in 10 bit, but scrubbing and timeline playback is 8 bit (or something that looks like 8 bit…The red and blue channels also see a slight luma shift when you hit play too) – However when I switched to AVCINtra 10 bit sequence the system behaved as I would have expected.
Thanks,
Paul
Freelance DS/Symphony
London
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