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Old September 27th, 2007, 01:01 AM   #1
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DV online @ 10-bit Uncompressed?

Does it make a difference if I online DV (24p - 16:9) at 10-bit Uncompressed before color correction? Is there any advantages to doing this (ie - more latitude in CC)?

Thanks,
-C
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Old September 27th, 2007, 12:32 PM   #2
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Yes and no. You'll get more latitude working in an uncompressed environment, but your footage itself will never get anymore latitude than it was shot with. If you are going back out to DV I don't know if you'll gain anything thought as it gets compressed down to DV again in the end.


-A
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Old September 27th, 2007, 12:33 PM   #3
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Don't understand your term "I online DV at 10-bits uncompressed ...". I understand the 10-bits uncompressed - but not your "I online DV".
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Old September 28th, 2007, 03:24 PM   #4
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TingSern - I mean when I batch capture at a higher resolution for color correction.

So Andrew, if I were to use Color 1.0, with Uncompressed 10-bit settings, would the affected media come out better than the DV source, if I then went to DigiBeta? Since Color Correction creates new media files, Uncompressed must be better for final output, right?

I'm just trying to understand Uncompressed footage going into and out of color correction verses DV.

-C
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Old September 28th, 2007, 08:11 PM   #5
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Obviously, if you can afford 4:4:4 uncompressed video capture, it will be better than any 4:2:2 or even 4:2:0 compressed. But, what is your input source (the video camera)? I haven't seen any video camera producing 4:4:4 uncompressed anyway - unless you are talking about those "mods" for DVX100. So, your capture will only be as good as your input. If your camera is producing only 4:2:2 - it is pointless capturing 4:4:4 uncompressed -the extra data is not going to appear like magic. Similarly for 8 bits - 10 bits - 12 bits argument. Batch capture the source data matched to your input source - will make most sense. No point overdoing it - extra data and demands made on your PC/MAC won't make the video better.
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Old September 29th, 2007, 01:28 AM   #6
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There can be some differences in image processing depending on how you capture/convert.

If you ingest via SDI, the deck will usually do some chroma upsampling/interpolation when converting from 4:1:1 to 4:2:2. FCP does box upsampling/interpolation, which doesn't look good.

2- In your case, you'd likely get better results from using nattress' plug-ins for FCP or color to upsample 4:1:1 to 4:4:4.

Workflow/button pushing-wise, I'm not sure what's best for you.
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Old September 29th, 2007, 03:36 PM   #7
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Interesting

OK - I digitized everything at DV via firewire.

Yet, at my work I have access to a AJA Io and a sony DSR-1800 which can take the content in at SDI/AES, 10-Bit Uncompressed (4:2:2).

So Glen, this would be a better workflow than just keeping the content at Standard DV, right?

I'm not sure about upsampling and interpolation, but the content played out of the DSR-1800 is NTSC not the native 24P that it was shot on. Should I be concerned with this?

Thanks again!
-C
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Old September 29th, 2007, 11:01 PM   #8
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Quote:
So Glen, this would be a better workflow than just keeping the content at Standard DV, right?
I think so...?

What you would do is re-capture from your tapes at 10-bit UC. The deck will upconvert the 4:1:1 chroma to 4:2:2 (this is a better job than apple's DV codec).

The files are bigger, and have the chroma upsampling burned in (so you don't need to render that, opposed to different workflows).

The potential problems:
-The re-capture is not always frame accurate. You should output a copy of your offline as a reference (to DV or whatever). Use the subtract composite mode to compare that to what you recapture. Some shots may come in +-1 frame... so you slip edit everything into place. Or... just play the sequence through and just fine tune all the timings of your edits; don't bother slipping everything into perfect sync with your offline, just re-do all the edits if they feel off. Export your OMF from the online (if you need to send an OMF for audio mix).

-To get to a 24p sequence... I'm not exactly sure if FCP can do that easily when ingesting over SDI. FCP doesn't grab the pulldown flags off SDI.

2- Workflow B:
Get G nicer from nattress.com
Or use FCP's 4:1:1 chroma smoothing filter

Apply that filter onto every DV clip. Change the order so that it's before your other filters.

From there it depends if you're going to apple color or not.
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Old September 30th, 2007, 01:34 PM   #9
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Great Glenn!

I think the uncompressed workflow "A" is it. Final Output will be to Digi-Beta (NTSC) then upconverted with pulldown to HDCAM 24P - I think RIOT! will have the headache of getting SD to HD.

Thanks for your thoughts,

-C
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Old December 24th, 2007, 02:31 AM   #10
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Q.C. Concerns

One last question on this topic:

If I re-ingest at 10- bit Uncompressed and use JES De-interlacer to reverse telecine to 24 FPS, will the footage be frame accurate of original DV imported source?

Does anyone have any experience shooting 24P DV (XL2) and up-converting to 4:2:2, then converting to 24p (via JES) even if the "flags" are unseen by the Final Cut's capture tool via "AjA Io 10-bit Uncompressed" capture preset?

We need to present an HD-CAM SR @ 23.98, 1080i and I am freaking out with Q.C. worries. We need to pass Q.C.!

Thanks,
-C
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Old December 24th, 2007, 08:37 PM   #11
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1- Remember that there is no 24p(sf) SD-SDI, so you can't move 24p material over SD-SDI.

You can do it over HD-SDI.

For SD-SDI, you have to add pulldown to convert the signal to 60i and it'll go over SD-SDI.

2- XL2: If it can shoot advanced pulldown, you might want to specifically avoid it unless. It might be difficult for their online system to deal with advanced pulldown if it can't remove it (it might not be able to).

3- Are you making a 23.98fps master, or a 59.97i/29.97fps/"60i" master?

I think all broadcasters won't accept 23.98, you'll need to make a 60i version. e.g. From your 23.98 master you'd make a 60i version for them.

If you need to make a 23.98 master, then I would suggest:
A- Shoot normal pulldown, unless you are sure that the finishing/online system can remove advanced pulldown.
B- Don't remove pulldown in JES unless you also do an upconversion at the same time. Because 24p won't go over SD-SDI.

4- Passing QC: They don't really check for ultimate technical quality.... e.g. you can do some crappy slowmo (e.g. field blending... not optical flow) and it'll pass QC. However, there are a number of other things they will ding you on (e.g. legal levels, timings, general errors/screwups).

You do need to know what you're doing and you generally need the equipment... e.g. VTR, a broadcast monitor, and scopes (preferably real ones... software ones usually aren't engineered correctly and without bugs).
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Old December 24th, 2007, 08:56 PM   #12
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Hey Christopher,

What are you trying to do?

Are you looking to do your own online to save on money?
What are your deliverable requirements? Is this for broadcast or what?
Have you thought about getting a facility to do your onlining/finishing for you?

2- I don't think your original plan will work since you can't do true 24p over SD-SDI (sorry I should've spotted that earlier!).

If you really need to tackle the onlining yourself, there is a better way of doing things. But you might be better off getting somebody else to do the online.
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Old December 24th, 2007, 11:55 PM   #13
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Ultimately, our distributor wants to overcharge us.
I am sure I can do this without them and their bloated fees.

They need an HD-CAM SR, NDF, 23.98 master with all 8 channels utilized (I won't bore you with those ridiculous details).

So, all 32 tapes were shot on the XL2 @ 24P Normal Mode.
I used JES de-interlacer to create 23.976 from the ingested DV material (via Firewire). Now I am thinking that this workflow isn't the best because of the distributors demands, thus I'm looking to provide the online editor with 4:2:2 chroma up-sampled material.

If the tapes are all shot at DV @ 24p over 60i (DV Wrapper), I should be good re-ingesting all 32 tapes over SD-SDI at NTSC, then reverse-telecine in JES at Uncompressed 10-bit, right?

Will this be frame accurate since I am not changing the frame order until after the material has been re-ingested at uncompress?

Thanks for your thoughts Glen and Happy Holidays,

-C
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Old December 25th, 2007, 02:39 AM   #14
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Wait- who is doing the online? Somebody else is doing the online? This makes a difference. If somebody else is doing an online, you should ask them what works best for them... because if you don't talk to them now, you'll get problems as they have to fix any mistakes you make. So talk to them ahead of time.

There are some variables here that are best dealt with by talking to them... especially how they will conform your project. EDL? FCP or Avid project? Are they redigitizing everything? Timecode issues, etc.

2- Will your distributor take a digibeta master?

SD origination bumped up to HD and then back down to SD broadcast (or DVD) smacks of silliness. On the other hand, that might change your workflow because your final deliverable is different.

Quote:
Will this be frame accurate since I am not changing the frame order until after the material has been re-ingested at uncompress?
The frame accuracy issues I was talking about happens when you recapture from tape via SDI... it's not a big deal, it's kind of part of the online process because they always have to fix it. e.g. If you sit there with a deck and capture the same timecode multiple times, sometimes the captured video is not in sync with the timecodes (they come in frames early/late). That tends to happen. It's not really a problem because they fix it every day.

There are other frame accuracy issues that can crop up with timecode and making a broadcast master... those other issues you definitely need to watch for.

2- The easiest way of doing things is to pretend that your footage is 60i and edit it that way. You can run the resulting 60i master through a Teranex (or similar device) to convert it to 24p... which might lose a small amount of quality. But this is the easy way of doing things and the quality is acceptable. It's lame but sometimes people do this (e.g. Hollywood movies... 24p origination, but it gets edited as 60i and there are cadence breaks all over in TV versions).

3- But anyways, you need to talk to the people doing the online beforehand.

If they recapture through SD-SDI, then you might have issues because 24p doesn't go over SD-SDI.
If they can do some sort of data workflow (e.g. Final Cut offline to Final Cut online), then that's kind of nice because you don't have that limitation. But then you need to talk to them anyways to figure that out.
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Old January 6th, 2008, 05:06 AM   #15
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Final Workflow?

I wanted to post an update with this as hopefully it will help someone else down the road. I ditched JES de-interlacer. It was told to me by many people that this degrades the quality of the original camera source. I also Ditched Cinema Tools as well, because of Cadence issues.

Here is my revised workflow:

Digitize 24p (2:3:2:3) DV Source material via SDI/AES (from DSR-1800) into FCP with AJA i/o, using the NTSC Pro-Res codec (720x480).

Chroma is up-sampled (used for compositing and color correction later).

Then, import into Compressor 2. Turn on Frame Controls --> Reverse Telecine. Make sure time says 23.98 @ 24p.

Change Pro-Res codec to Up-convert to final output resolution: from 720x480 to 1920x1080.

Submit in Compressor and wait for 34 hours of footage!

Days later... Start editing!

Thanks for all your thoughts guys.

-C

Last edited by Christopher Drews; January 6th, 2008 at 05:10 AM. Reason: mistype
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