Which Flavor of DNxHD Truly Visually Lossless?

[Peter Moretti]

I realize that DNxHD comes in different varieties. Are any of them visually lossless with an HD 4:2:2 1920 X 1080 signal? (Essentially trying to compare DNxHD with the codec Cineform uses in Neo HD.)

Thanks much.

[David Parks]

It depends on one's perception of "Visually" lossless. I'm not a codec scientist/expert like David Newman over at Cineform. But, I can tell you that I cannot tell the difference between Avid 1:1 (which is compressed) and
DNXHD 220. And what I've seen of Cineform is very impressive as well. But, I (nor many people) are qualifed to truly objectively compare the two.

I'm sure in the coming months we're going to see all kinds of press articles and musings comparing DNXHD, ProRes, Cineform, , etc. Same thing happened in the 90's when non-linear editing went broadcast.

In the end, go with what looks good to you but put more emphasis as to what is the best workflow for your project.

Just my opinion.

[Peter Moretti]

Thanks Dave. There are a few things I want to accomplish and am still trying to figureout:

1) Switch a project from Vegas to Avid or vicea versa (within reason). I believe DNxHD can be installed in Vegas.

2) Intercept a 4:2:2 1920 by 1080 signal before it meets HDV compression. This means using HDMI, SDI-HD or component out. (HDMI is my preference b/c it could be done with an HV20 and an Intensity card.)

3) Apply a visually lossess codec on the fly so the footage can be stored on a reasonable hard drive configuration. Cineform does this very well (and has the added benefit of pulldown removal), but perhaps DNxHD36 can be used.

As you can see there are a lot of cross compatability issues here.

Thanks for any insights!

[David Parks]

That's quite a workflow. First offf, DNXHD is a Quicktime
codec that can be edited only in Avid. I'm not too familiar with Vegas other than I know that it can edit a lot of formats. And DNXHD 36, (which I haven't seen but DNXHD 110 probably looks better) is for HD offline as I understand.

If 4:2:2 color space is really important for capture then Avid is out for an initial injest solution because there is not curently a capture solution with HDMI and Avid.

I'm not sure what your trying to accomplish by mixing edit apps. Personally, if your not producing a major project for Discovery Channel or something, I wouldn't get too caught up in the 4:2:0 HDV vs. 4:2:2 quality comparison. Go with the platform that you like to edit in the most. If it is Avid, I would go in HDV because Avid uses smart splicing on HDV at up to DNXHD 110. It looks good and holds up well into downconvert. If it is Vegas, stick with it.

If you need to use the Intensity Card ( and not Vegas), I would look at Adobe Premiere 2.0 (I guess it will be CS3 soon) for ingest from HDMI or stick with Vegas.

Sorry I'm not much help here I guess because I'm not sure what type of projects you're editing.

[Chris Swartz]

Just wanted to post up some pics of my Portable Intensity Capture Station.

I am running it through some paces, but do plan to make them available to interested parties.

One thing I have tried is to capture Uncompressed, Blackmagic Motion Jpeg compressed, and Cineform Compressed clips with the capture station. From there I imported into After Effects and then exported to Quicktime with the Avid DNxHD codec. It really isn't too slow of an export. You must have Avid Media Composer installed to have access to the DNxHD 220 resolution. Once the file is done exporting out of After Effects, fire up the Avid and import. It works great if you just have to edit in the Avid and don't mind the extra time in the transcode.

Here are the specs

Intensity Capture Station

Portable Case w/ handle
Silent Power Supply 500 Watt
Micro ATX Motherboard (Intel)
Intel Core 2 E6600 2.4 Ghz
Geforce 8500
Processor Cooler
2 Gig Ram
DVD Burner
2 500 Gig Seagate Drives
Intensity HDMI Capture
Keyboard / Mouse
Win XP Pro SP2
7 Inch LCD

Let me know if you have any questions.

[David Parks]

Chris,

That's pretty nifty. Sort of an HDMI low cost version of a Wafian Recorder. I think this works great if you're going to edit in BMagic or Cineform codecs.

But if one insists on editing in Avid, what is the advantage over going in HDV Firewire other than 4:2:0 vs. 4:2:2??

HDMI>to Cineform Codec>AFX>QTDNXHD>Avid MC (Seems like you loose the advantage of 4:2:2 by this point by transcoding, twice??) And again when you're ready to output/export.

Firewire>HDV DNXHD 110 (Native HDV Smart Splicing No transcoding during edit.) Direct digitize.

I think Cineform Neo would take a step out of the process allowing transcode into QT DNXHD w/o having to go into AFX.

I'm not trying to diss your solution here and more and more people are using HDMI. I think Adobe PPro works better in this case because you can edit in Cineform codec and cuts time/transcoding.(Just my opinion) It just highlights how proprietary Avid operates.

But cool tool anyway.

[Chris Swartz]

I definately understand what you are saying. I certainly don't think you are dissing my system.

As far as I know the workflow is great if you are going to use it for a studio solution and can use the uncompressed HDMI output of your camera. In this case you are keeping as much color info as possible and I think it stays in 4:2:2 even through the 2 transcodes. Actually you can capture to Uncomressed and only transcode once, it eats up a lot of space, but if you need to have that color space, it's worth it. This is a great option for green screen work and a cheap camera. Once you have put that signal on tape you lose a ton of information.

As for Avid, it is disheartening that they are so closed in their approach to hardware, but I just love editing in the avid, so anyway to keep me in that editor is great. I've thought about PP, and it is getting better, much better especially with it's integration with the other Adobe apps, but I still think that for a standalone editor, Avid is the cream of the crop.

Chris

[David Parks]

Originally Posted by Chris Swartz

but I still think that for a standalone editor, Avid is the cream of the crop.

Chris

Couldn't agree more. No arguement there.