4:2:2 component acquisition Vs. ProRess 422

[Frank Guthrie]

Hi there,

I have a question in regards to up sampling the Chroma of my footage, to get better color in... lets say Color or Colorista.

I record on a JVC GY-HD100U into an 80 Gb DRHD100 Firestore. I can get either a QuickTime, or .m2t, both at 4:2:0.

I was looking at Fernando Orozco's thread where he explains how, "the material is recorded in 4:2:0 but I found that is easier to handle and process video in 8-bit uncompressed (try to CC a clip in HDV and render, do the same thing in 8-bit, you will see the difference), another additional benefit is: you are processing video with a better codec and that means less compression artifacts and better quality to processed clips..."

Fernando shows two screen-shots of his settings (HDV 30p to Uncompressed 8-bit 4:2:2 30p AND HDV 24p to Uncompressed 8-bit 4:2:2 24p,) using MPEG Streamclip....

Here is my question: instead of converting hdv 24/30p to 8-bit, could you 1) create a project in Final Cut, using the Apple ProRess 422 settings, thus creating an environment that has a 4:2:2 Chroma setting, and 2) import your 4:2:0 QuickTime from the Firestore, edit, and then 3) send to Apple's Color for CC as a ProRess 422 project?

I'm trying to avoid building a $5K to $10K Raid/Kona Taco stand for composite recording, if - from what I've been reading, component doesn't give you better pixel quality, just extra Chroma sampling...

Thank you for your help,


Frank

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[Nate Weaver]

Frank,

FCP is built to handle HDV correctly, if you give it the option. Check out this discussion and my post:

http://www.dvinfo.net/conf/showpost....18&postcount=9

The short story is, you can't gain chroma resolution by transcoding to a better codec before processing, but you can gain better quality by rendering your color or effects to a better codec AFTER processing. That goes double for rendering your effects back to HDV format, which thankfully FCP allows you to skip in about 2 or 3 different ways.

HOWEVER, if you choose to go through with the heartache of uncompressed or SDI capture while shooting with a computer, you do in fact gain more chroma res which can be put to good use later on with your color correction or what-have-you.

My opinion has always been however...low-budget production is hard enough without having to drag a computer along for every shot. Besides, in the end it's not the picture quality that makes-or-breaks your project...

[Tim Dashwood]

Originally Posted by Frank Guthrie

Here is my question: instead of converting hdv 24/30p to 8-bit, could you 1) create a project in Final Cut, using the Apple ProRess 422 settings, thus creating an environment that has a 4:2:2 Chroma setting, and 2) import your 4:2:0 QuickTime from the Firestore, edit, and then 3) send to Apple's Color for CC as a ProRess 422 project?

Apple's Color only accepts files with a source codec in 4:2:2, with the exception of AIC, which does also seem to work with Color.

Therefore your ProRes4:2:2 sequence would not import the HDV source clips into Color unless the source clips in your sequence were converted from HDV (4:2:0) to ProRes4:2:2 (or one of the other approved 4:2:2 codecs.)
You can use media manager to batch convert clips to a different codec.

Once you lock your cut the best plan might be to consolidate the project using Media Manager into a new project and re-encode the portions of the clips used in the cut (with handles of course) to ProRes422. You would then be able to send that to Color.

[Frank Guthrie]

Thanks Nate, thanks Tim for your responses,

So, if I'm reading this right, for my low-budget pipeline, it should be something like this:

1) Record HD, 720p into the Firestore (.m2ts OR QuickTimes), giving me a 4:2:0 Chroma space footage...

2) Follow Fernando Orozco's "up-Chroma technique" using MPEG Streamclip, to convert the footage to Uncompressed 8-bit 4:2:2 24p... OR media manager to batch convert clips to a 4:2:2 Codec (Tim Dashwood)...

3) Then in Final Cut 6.0, start a project in ProRes422 settings - 4:2:2 Chroma space, and then Import the footage - converted to Uncompressed 8-bit 4:2:2, edit, and then send to Color for CC...

4) Bring back into a the ProRes422 workspace...

I agree that Story rules, not the tools, but its so great to explore/learn - with your help, how to take advantage of the tools I just blew my savings on.

I just saw the movie Once, and for the first ten minutes I was wondering if the movie was shot on a cell phone... or an Etch-a-Sketch. However, once the Story kicked-in, the acting, the scenary, I was entertained, fully immersed, and didn't care who, where or when they shot such a great movie!

Again, thanks for your help,

Frank
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[Tim Dashwood]

I think what Nate and I were both getting at is that it isn't really necessary to convert all of your mpeg2 HDV clips to uncompressed or ProRes BEFORE you start editing.
The beauty of the DR-HD100 workflow is that you can start editing immediately.
So just edit natively in HDV from the quicktimes created in the DR-HD100.
When you lock your cut just convert only the pieces you used to a 4:2:2 codec.
You will save a lot of hard drive space and prep time this way.

[Nate Weaver]

Yes. You can't gain anything by converting HDV to uncompressed before a processing step such as color or graphics.

Put another way, a frame of HDV is decoded into an uncompressed frame buffer before processing anyway; this has to be done before any processing can be performed in the first place.

What counts is the codec you encode to AFTER the effects are performed.

[Frank Guthrie]

Hi guys. Thanks again for your clarification.

Just tried it:

1) Shot.

2) Edited natively in HDV from a Quicktimes in the DR-HD100.

3) Locked the footage.

4) AFTER the effects were performed, I brought them back into a 4:2:2 codec sequence.

Thanks for your help. it made a huge difference!

Frank
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www.710Films.com

[Dave Beaty]

Originally Posted by Tim Dashwood

Apple's Color only accepts files with a source codec in 4:2:2, with the exception of AIC, which does also seem to work with Color.

Therefore your ProRes4:2:2 sequence would not import the HDV source clips into Color .

I thought Color would import HDV? And then you could render out of Color to ProRes. Although, I read about some problems with the clips being out of sync coming back into FCPro from HDV source.

Dave B

[John Carrithers]

Just an alternative to ProRess or Uncompressed 8 Bit.

My background is an editor. In recent years clients have supplied me with their footage on firewire drives and a popular acquisition format seems to be DVC PRO HD. It woks well with FCP, is stable and isn't very taxing on your system (not nearly as much as uncompressed 8bit). I've used other blackmagic cards for SD capture for years and have been very intrigued by their Intensity card which can convert HDV to just about any FCP quicktime formats, including DVC PRO HD, through an HDMI input. I've got the JVC HDV deck with HDMI out so I've been curious to try this. It seems like it might solve the few concerns I have my camera and editing, timecode breaks on capture, compression artifacts in certain situations, etc.

Unfortunately I haven't been able to try this because the card requires a PCI express slot. The two systems I use are a mac book pro and a G4 dual 1.42...not a PCI express slot in sight. It seem seems silly to buy a several thousand dollar machine to thow a 250 dollar card into. Especially considering I'm pretty happy with what I have to work with.

Just a thought. Has anyone tried this and had better results with color correction, capture, etc.?


JC

[Nate Weaver]

Originally Posted by John Carrithers

Just a thought. Has anyone tried this and had better results with color correction, capture, etc.?

It's convenient and works when you don't have ProRes available. But it's 8 bit, and involves resolution cheats for a given format (720p becomes 960x720 instead of 1280x720, and 1080p becomes 1280x1080), so it's not ideal.

[Joseph H. Moore]

another step to consider is using a chroma upsampler (like nattress)before doing work in color or AE or whatever, edpecially if you're gonna do more than simple grading.