Final Cut and Varicam & HDV

[Sean Oneil]

First off, I’d read this article by Gramme Nattress:
https://www.kenstone.net/fcp_homepage/beyond_dv_nattress.html

Basically, capturing Varicam using your Kona is not native capture. You can only capture native DVCProHD into Final Cut by using Firewire and a Panasonic AJ-1200. The reason is because SDI only transmits uncompressed video. That is why it’s saying 1280×720 in your capture settings. Your VTR is taking the native format on the tape and converting it to uncompressed so that it can output over SDI. Then the Kona is capturing SDI uncompressed and converting it back to DVCPro on the fly (hence the converting back to 970×720). When it converts “back” to DVCPro, it is not the same DVCPro that originally existed on the tape. It is a lossy recompression process. You lose a generation. It doesn’t “remember” what it used to be (if that makes any sense).

A lot of people find this confusing. Part of the reason is because you CAN capture natively over SDI on an Avid using a Panasonic AJ-1700. The reason is because it’s not really SDI. It’s called SDTI which is actually more like Firewire than it is SDI. But neither the Kona nor any other Final Cut product can capture SDTI.

You can still use the Kona SDI->DVCProHD workflow for offline editing. But for the finishing you’ll definately want to batch re-capture your final edits as uncompressed. In fact, I’d recommend doing this especially since you’re mixing in HDV footage. Don’t capture the HDV natively. It’s just headaches and will not playback well on a DVCPro sequence.

So capture both formats as the same thing for the offline (doesn’t matter what it is since it’s offline editing). Then when you master, batch re-capture both of them as Uncompressed 720p if your final delivery needs to be 720p. Or if you’re delivering 1080i, batch re-capture both of them as Uncompressed 1080i.

Sean

[Peterson]

Sean-

Thanks for the educational post. I am an editor with a fair bit of experience in the old Avid paradigm of offline low res / reconform high res but up until now very little pro work in FCP and none yet with the multiple flavors of HD out there, so I am listening a lot and trying to get up to speed.
You wrote “You can still use the Kona SDI->DVCProHD workflow for offline editing. But for the finishing you’ll definately want to batch re-capture your final edits as uncompressed.”

Since you explained that capturing the DVCPro HD via SDI results in a lossy recompression process, am I getting you correctly that for the batch re-capture you recommend using firewire? Is there a tight TC relationship between the SDI footage and the firewire footage? I ask this because I have read (& I stress read rather than experience as I have yet to use this workflow) that the firewire is not always 100% in terms of frame accuracy, especially for a reconform. Has this not been your experience?

Thanks –

Peter

[Walter Biscardi]

[Sean ONeil] “Basically, capturing Varicam using your Kona is not native capture. You can only capture native DVCProHD into Final Cut by using Firewire and a Panasonic AJ-1200. The reason is because SDI only transmits uncompressed video”

That’s actually incorrect regarding the Kona series. It does natively capture DVCPro HD via SDI and in fact, according to AJA the image is a little better using that method. I’m not sure how other capture cards handle this process, but it is a lossless transfer using this method.

Walter Biscardi, Jr.
https://www.biscardicreative.com

Director, “The Rough Cut”
https://www.theroughcutmovie.com

Now Posting “Good Eats” in HD for the Food Network

“I reject your reality and substitute my own!” – Adam Savage, Mythbusters

[Walter Biscardi]

[airplanesteve] “For instance, why is the format 1280×720 on input but the sequence is 960×720? Should I convert all my varicam footage over to 1080i out of the deck to match more cloesely with the HDV resolution?”

DVCPro HD is natively 960×720 so it has a slight anamorphic look to it. That’s why the timelines are 960×720 but FCP automatically stretches it back out 1280 on playback.

Depending on how much HDV footage you’re mixing with the Varicam footage, that will really determine whether to capture everything at 1080 or 720. The Kona can capture any HD signal to DVCPro HD so I would say experiment with your footage.

We pretty much cut all day now with Varicam footage and though we’ve been bringing it all in natively at 720, we’re going to do some testing with 1080 since our final delivery on all the shows is HDCAM anyway.

Walter Biscardi, Jr.
https://www.biscardicreative.com

Director, “The Rough Cut”
https://www.theroughcutmovie.com

Now Posting “Good Eats” in HD for the Food Network

“I reject your reality and substitute my own!” – Adam Savage, Mythbusters

[Walter Biscardi]

[peterson] “You wrote “You can still use the Kona SDI->DVCProHD workflow for offline editing. But for the finishing you’ll definately want to batch re-capture your final edits as uncompressed.””

actually there’s no need for that using the DVCPro HD codec. We work strictly in that codec for capture to final delivery here and it’s identical to working wtih uncompressed 720. That’s the beauty of the DVCPro HD codec, it negates the need for uncompressed recapture. We capture, color correct and master out to HDCAM from the DVCro HD codec here.

Walter Biscardi, Jr.
https://www.biscardicreative.com

Director, “The Rough Cut”
https://www.theroughcutmovie.com

Now Posting “Good Eats” in HD for the Food Network

“I reject your reality and substitute my own!” – Adam Savage, Mythbusters

[Airplanesteve]

Wow, thanks for all the help. I went to sleep and woke up with all this to read. I will do some testing and get back to you. The issue between SDI capture and Firewire is interesting. I was hoping to use the Kona card because I thought it would be a better match between formats if I used the HD Component outs of my HDV deck into the Kona card and have the SDI feed out of AJ1200…. then the card takes both formats and converts them for FCP. One more question if I might, is there any benefit to editing in 1080i? v 720p. Any thoughts would be most helpful! Cheers.

steve at airthis

[Gary Adcock]

[airplanesteve] “. The issue between SDI capture and Firewire is interesting. I was hoping to use the Kona card because I thought it would be a better match between formats if I used the HD Component outs of my HDV deck into the Kona card and have the SDI feed out of AJ1200…. “

First off according to the specs I have seen there is no difference between the SDI > DVCPROHD conversion on the Kona Board vs the direct FW capture. (this is only true with the Kona however)

Secondly– your bigger problem is your workflow. You are trying to destroy your progressive true HD varicam footage to match the consumer HDV– this is really backwards. The editing solution should determined by the higher quality / quantity of video. You are loosing all of your quality when you “dumb” down the 720p HD @ 4:2:2 footage to the HDV60i @ 4.2.0.

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[Airplanesteve]

Thanks for that. I didn’t mean I wanted to dumb down to HDV, I thought I would capture them both at the DVCPRO HD codec on the Kona card. But I was wondering if I would be better off having the AJ1200 output 1080i rather than 720p and capture them both at 1080i 29.97 DVCPROHD codec that is on the kona card? Any thoughts?

[Sean Oneil]

[walter biscardi] “That’s actually incorrect regarding the Kona series. It does natively capture DVCPro HD via SDI and in fact, according to AJA the image is a little better using that method. I’m not sure how other capture cards handle this process, but it is a lossless transfer using this method.”

Walter, I’m sorry you feel that way but you are completely misinformed and/or confused about this. Any video engineer can tell you this. HD-SDI transmits uncompressed video. It cannot transmit compressed formats natively any more than you can connect to the internet using mic cable. It just doesn’t work that way. While there does exist a protocol called SDTI which can transmit these types of streams over SDI chips – Kona cards do not support this (nor does Blackmagic or any other FCP card). Nor do they really need to because the same thing can be accomplished on a Macintosh using Firewire.

If you don’t believe me, look at a scope as it’s coming in. Or just look at your capture settings for Kona DVCPro. Why is coming in at 1280×720, but being stored as 970×720? Please, feel free to explain this.

If you think giving it a second round of compression looks just as good or even looks better, you’re certainly entitled to that opinion (even though the concept is incredibly ridiculous). Come to think of it, the very notion that it can “look better” in and of itself proves that it is not native capture. If it were native capture it would look identical because it would BE identical. Thus, it couldn not look better.

I’m not going to argue over whether or not the loss is significant enough to deter someone from using this workflow. To each his own. But don’t fool yourself into thinking this is a lossless workflow because I promise you it is not lossless.

Furthermore, even if it were native capture and layback (which it isn’t), a native workflow is only lossless for cuts only video. Any effects, transitions, color correction, or anything that needs to be rendered (key word: rendered) goes through yet another dose of recompression. This is why batch re-capturing at uncompressed is the only way to ensure that the video is identical in quality as it was on the original tape.

Sean