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Question from a non-Avid guy…
We recently shot a series of commercials for a hospital in our area in HDV with my Z1. I happen to be a CineForm/Adobe PPro guy (yes, yes, I know….) and I’m used to handling HDV with no sweat whatsoever.
For this spot, the studio wants to edit on their Avid Media Composer 1000 with Meridien boards in it…analog I/O (I believe that is accurate anyway…)
I decided that rather than doing a quickie down-convert out of the HDV camera to DV, we’d be better off if I could take HDV’s 720×540 chroma res to a 4:2:2 codec directly (bypassing what I suspected would be a rather obliterated 4:2:0 HDV > 4:1:1 DV conversion) for SD post on the Avid.
I downloaded the free Avid codecs and put them on my PC and used ProCoder to transcode the HDV to (on the Avid editor/owner’s recommendation)”Avid Media Composer Meridian JFIF NTSC 601 2:1″ This was a bit of a time investment as the Avid codec without it’s accompanying boards seems to take some time to encode…and I also discovered that this system can’t import any clips over 2 Gigs the hard way (even though a 4 Gig Meridien QT clip plays back fine on my PC), but I thought in the end, the quality difference we would see would be well worth the extra effort and deliver a better product for the client.
My surprise came when I did do a quickie downconvert via FW between the Z1 and my PDX10 to letterbox 4:3 DV for a comparison to see just how much better the more involved workflow was…and there really wasn’t much difference.
I’m assuming I’m missing something because the resulting Meridien files were smaller than the HDV files..therefore had a data rate less than DV, this while showing a 2:1 in the dialogue which I assumed was compression ratio…and the relative picture quality between the two just wasn’t that remarkable. Needless to say, I kind of feel I wasted my time as I could have simply plugged in the FW cable and done the conversion in a small fraction of the time it took to ingest HDV and convert to Avid codec for what I thought would preserve the quality much better.
I’m interested in perspectives from Avid users here. I had v2.5 Media 100s in 1996 that didn’t have a 2 Gig file size limit. This system is a dual-stream uncompressed, but for storage reasons we went with 2:1…DV has a larger data footprint and is considered to be in the 7:1 compression range…I don’t get it.
Enlighten me please. This probably won’t be the last time we need this workflow…am I really just as well off to make a bonehead DV dub and have the editor ingest component analog than converting directly to Avid’s own codec? (and yes, I realize the system I’m talking about is apparently 5 years old and the last update was a year or two ago…)
Thanks
TimK,
Kolb Productions,
Creative Cow Host,
Author/Trainer
http://www.focalpress.com
http://www.classondemand.net -
9 Replies
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Err ok lots of Q’s I’ll see if I can help at all!
DV File sizes are 2gbs for sync reasons, FCP and Avid can both use greater sizes but will doutless to say fall over, this is not the case however if you are using DV420 as a digitize setting because you are not using a quictime DV codec, just a maths calculation to compress. If you then try to export that footage as DV then the 2gb limit will hit you. I’m stunned that 2.1 is smaller than DV, it’s just not possible. Even if you import a DV clip and reexport it as 2.1 it will get bigger in size!.
I shot a pro for the BBC last year using HD and just captured using the SD 422 convert (YUV out) from the camera, only for the online though. For the offline I just plugged into firwire for downconverting. The whole point with HDV in the UK is that nobody is yet accepting it as a broadcast delivery format so at some point you will loose HD. The same is generally the case for corporates and web realises so why use an intermediate codec to edit? Edit native in FCP or 422 SD in Avid. If you devliver HD then deliver HD not HDV you will want to use HD for sound sample res reasons anyway right?
The main thing I will say is that Snell and Wilcox and many other companies make very expensive SD to HD convertors. They wouldn’t sell a single one if software or a 3k sony camcorder could do it as well would they now.
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Thanks for the reply.
Well…since I’m not capturing on the Avid…all capture/conversion info there isn’t really what the challenge is…
The data rate is a weird, weird thing. The 2 Gig file limitation seems to be in force for importing QTs as well, not just DV. (BTW, why in the freakin’ world does this box have to “import” a file that’s already set-up as Avid compression?…it takes forever too…).
Maybe there is some difference in how the codec reacts with QT on Windows? The funny thing is that I can play back the Avid file on my PC in QT 7 without issue…the Avid Errors out if the file is over 2 Gigs and it refuses to import it.
2:1 Meridien HAS to be better than DV? Right?
…I don’t really care what Snell and Wilcox makes…I have a broadcast monitor and my eyes…at the moment I have a day and a half wasted on this issue because the plain old FW out DV looks as good as the Avid codec at the moment…though I’m guessing this and the low data rate must be connected…
TimK,
Kolb Productions,
Creative Cow Host,
Author/Trainer
http://www.focalpress.com
http://www.classondemand.net -
Tim,
Let me try to help here. Avid Meridiens do not take in video via FW. Only through the BOB or as an imported file. All imported files have to be converted into OMF. A QuickTime file using an Avid codec still has to be rewrapped as OMF, hence the import process. If everything is done correctly in the conversion to the Avid-formatted file, then the software engages a Fast Import mode, which is essentially a file copy/wrapping step. If something is slightly wrong, it takes longer. Generally about the same, as if you had used the animation codec or something similar.
The JFIF 2:1 codec means that the resulting video is encoded as 720×486, 8-bit, 4:2:2, D1 aspect ratio, value-rate Motion JPEG at 2:1 compression (max) at 29.97 (in NTSC). Your file size should be around an average of 2 min./GB with this codec, but since it is a variable-rate codec, this isn’t an exact amount (plus audio, of course).
The 2GB file limit has to do with dealing with legacy OS types and versions, since you might create a file that is intended to run on an older machine and, therefore would have a problem. It’s an Avid thing, but mainly to protect older systems.
Unfortunately, you’d probably get the best results by simply going component analog SD out to a DBeta deck (or similar) and then ingest via SDI into the Avid. That would be real-time (twice). Remember also that in Avid land, you can mix any of the 2-field compressed codecs, any of the 1-field compressed codecs, but you cannot mix compressed and uncompressed media, nor 2-field and single-field media. Hope this helps.
Sincerely,
OliverOliver Peters
Post-Production & Interactive Media
Orlando, FL
http://www.oliverpeters.com -
Thanks Oliver,
yes, I know the Meridien doesn’t ingest FW…that was the reason for the file conversion in the first place. I’m not confused about this, the initial response had the FW content in it. Also…this system has no SDI I/O, so it’s analog only.
The codec stuff you mention is what I expected from this codec, but what I got was a about 2 Gigs every TEN minutes. Less than DV. FAR more than 2:1 judging by the data footprint, even though that was the setting I chose…
That is the focus of my issue…
TimK,
Kolb Productions,
Creative Cow Host,
Author/Trainer
http://www.focalpress.com
http://www.classondemand.net -
Tim,
It sounds to me like it was set to 20:1, not 2:1. That would also be a valid Meridien compression setting. Something is wrong. I would recommend simply compressing to Animation codec at the right settings and taking the time hit on the Avid side. Might be some sort of codec conflict with ProCoder or the version of QT on that machine.
Sincerely,
OliverOliver Peters
Post-Production & Interactive Media
Orlando, FL
http://www.oliverpeters.com -
[Oliver Peters] “It sounds to me like it was set to 20:1, not 2:1. That would also be a valid Meridien compression setting. Something is wrong. I would recommend simply compressing to Animation codec at the right settings and taking the time hit on the Avid side. Might be some sort of codec conflict with ProCoder or the version of QT on that machine.”
Yes, that was what I was thinking (the 20x)…but having re-checked the dialogue countless times, I know that I didn’t set it that way so I suppose you’re right-that iyt must be some sort of bug.
We’ll go with the Animation settings.
Thanks again.
TimK,
Kolb Productions,
Creative Cow Host,
Author/Trainer
http://www.focalpress.com
http://www.classondemand.net -
[Tim Kolb] “Also…this system has no SDI I/O, so it’s analog only.”
Tim,
You could, of course, simply capture the HDV wild into the Avid, using the downconverted SD CAV signal straight into the Avid BOB. Capture at 2:1 in real-time.
Sincerely,
OliverOliver Peters
Post-Production & Interactive Media
Orlando, FL
http://www.oliverpeters.com -
That’s what i suggest in my email, it must be the quickest way all in all. Unless u don’t own the deck or camera?
Justin
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I own the camera…I was attempting (as I mentioned in the initial post) to bypass a rather rudimentary downconvert to DV in the camera. Analog component out from the camera HD is clean, but the SD downconvert goes to 4:1:1 DV as far as I know. In the end it appears that would have been just as good as what I ended up with, but that is only because the conversion to Avid codec directly went out so severely compressed.
TimK,
Kolb Productions,
Creative Cow Host,
Author/Trainer
http://www.focalpress.com
http://www.classondemand.net
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