Highlight banding issue with HDV

[Jeremy Garchow]

I get this with 10 bit material all the time, HD or SD. Dopes it look kind of a like a plaid pattern? Is your SD timeline 10 bit perhaps?

The only way to get around it is to either lower your whites way down, or after all of your other filters, add a desaturation filter and make sure that the level is 0 (so you really aren’t adding any value to the desaturation). This will get rid of that weird pattern. I find it only happens on clips that are scaled and if you are putting your HDV timeline in an SD timeline, your while sequence is scaled.

Jeremy

[Graeme Nattress]

Capturing as DVCproHD is transcoding though. And to say you’ll have a better quality, is false. How can going from 1440×1080 to 1280×1080 help the image? How can taking something that’s already over-compressed and compressing it again help? It can’t. It can only make things worse. Sure, it can help for some workflows, but quality is not one of the things it helps.

Graeme

– http://www.nattress.com – Film Effects and Standards Conversion for FCP

[Graeme Nattress]

Does it occur rendering in a native HDV timeline? Have you tried an 8bit SD timeline to see if it’s a 10bit issue? What quality of scaling do you have turned on in your timeline?

Was it the camera or your capture card that did the downconversion to SD? The cameras, I’m told, have very poor sub-standard downconversion built in.

I don’t know precisely what the answer is as I’ve never seen it before, but see if any of the above spark an idea and perhaps help get to the bottom of it.

Graeme

– http://www.nattress.com – Film Effects and Standards Conversion for FCP

[Walter Biscardi]

[Graeme Nattress] “Capturing as DVCproHD is transcoding though. And to say you’ll have a better quality, is false. How can going from 1440×1080 to 1280×1080 help the image? How can taking something that’s already over-compressed and compressing it again help? It can’t. It can only make things worse.”

In our real-life day to day workflow here, it doesn’t make it worse at all. Everything looks identical to the original HDV captures even after it’s been processed with several layers of Color Correction. I’m sure if we zoomed way in and compare pixel by pixel the original to the finished project, we’ll see the added noise, but just looking at the image on the Sony broadcast monitor and Panasonic Pro Plasma monitor, the transcoded image is outstanding.

Walter Biscardi, Jr.
https://www.biscardicreative.com
HD Editorial & Animation for Food Network’s “Good Eats”
HD Editorial for “Assignment Earth”

Read my blog! https://blogs.creativecow.net/WalterBiscardi

[Graeme Nattress]

Might not make things, for you, visually worse, but you’ve got to know that behind the scenes you’re adding another layer of unneccessary compression. It’s probably only the fact that HDV cameras are not that great to begin with that’s not letting you easily see the 18% lower resolution. And then, that’s one more layer of compression that’s been put on the video before broadcast and it all adds up.

Of course, it would be wonderful if we all had hard drives big enough to go fully uncompressed, and it would be wonderful if HD decks were also totally uncompressed, but that’s not reality. We must accept some compression, but in doing so, we should tailor the compression for the job and keep it sensible. DVCproHD is a camera acquisition codec that’s great for native editing of such footage, but it was never designed as and due to it’s smaller than needed raster size, not really suitable as an intermediate codec, and certainly lacks robustness over multiple compressions. I guess that’s why Apple invented ProRes, which was designed for intermediate work, has 10bits, is full raster, and will stand up to multiple generations.

Graeme

– http://www.nattress.com – Film Effects and Standards Conversion for FCP

[Walter Biscardi]

[Graeme Nattress] “Might not make things, for you, visually worse, but you’ve got to know that behind the scenes you’re adding another layer of unneccessary compression. It’s probably only the fact that HDV cameras are not that great to begin with that’s not letting you easily see the 18% lower resolution. And then, that’s one more layer of compression that’s been put on the video before broadcast and it all adds up.”

Yep, totally agree the compression is added, I’m just saying in a real life Post Workflow, it’s not causing any issues and in fact the HD network we deliver this program too is telling we are delivering the best look HD they are receiving. Yes, go in and look at the image at 200 – 500% and it’s very obvious the additional compression is there. I’m just saying in regular playback viewing any monitor at normal distance, the difference is nearly imperceptible.

And yes it would be nice if we could all work in uncompressed pristine quality all the time, but we can’t and the HDV to DVCPro HD workflow is completely viable and passes Network Quality Control with no issues.

Walter Biscardi, Jr.
https://www.biscardicreative.com
HD Editorial & Animation for Food Network’s “Good Eats”
HD Editorial for “Assignment Earth”

Read my blog! https://blogs.creativecow.net/WalterBiscardi

[Graeme Nattress]

And when you get FCS2 with ProRes, you can elevate that quality still further!

Graeme

– http://www.nattress.com – Film Effects and Standards Conversion for FCP

[Matt Devino]

Hey All,
I get this problem with FCP all the time in anything that is 10bit YUV. The only way I can get around it it to either play out my timeline without rendering, which for some reason keeps the banding from occuring when it’s a real time effect, or going into my sequence settings and rendering everything at white (not super white) 8-bit YUV and motion filtering at best instead of normal or at RGB. The weird thing is you will only see this on an interlaced monitor, it doesn’t show up on a progressive monitor. You can actually open up your color meters and see the artifact in your scopes! It’s definitly a final cut rendering bug that apple needs to fix, and I hope 6 will fix it. It doesn’t have anything to do with the fact that you are using HDV, as it happens with D5 material, and 10bit SD material, it is anything that is 10-bit YUV. HDV isn’t 10-bit, but final cut defaults to rendering everything that is YUV at 10-bit super white instead of whatever it’s native format is. I hope this helps!
-Matt

[Graeme Nattress]

Thanks Matt. I’ve not seen this 10bit bug myself, but I’ve seen a few other 10bit bugs in the past. I hope you’ve reported this to Apple with enough information so that they can reproduce the bug.

Graeme

– http://www.nattress.com – Film Effects and Standards Conversion for FCP

[Matt Devino]

I haven’t reported this to apple, do you know where/who I would report it to? Also I just re-read my earlier post and realized my wording wasn’t perfectly clear: if you render at RGB it will also fix the problem. Sorry if there was any confusion.