I'm at a loss to understand the rationale here.

You wish to transcode from a 25mbps 4:2:0 mpeg-2 codec that's reasonably easy to edit to a 50mbps 4:2:2 codec that's fairly easy to edit.
I suspect you've fallen into a trap in your thinking.

1) HDV might be problematic to edit, some people do seem to have issues with it and Vegas so:

a) Cineform isn't a long GOP codec and is therefore less likely to stress Vegas and cause problems
b) Cineform is a pretty much a lossless codec, no harm done to your image quality.

Replace Cineform with XDCAM 422 and you might keep b) but you loose a). because XDCAM is another long GOP codec that seems to place more strain on the system as the data rate is double. Certainly so far in my brief tests I've had some wierd thing happening with it once I pushed V9 a bit hard. You could be jumping out of the frying pan into the fire.

Bob

I missed the part in the original post about HDV. I thought you were starting with a MXF file FROM an EX camera... sorry!

Jay,
it's not an entirely silly idea. It could be a very good idea IF Laurence needs to use an intermediate. This is generally when you want to use the best codec feasible to avoid doing too much harm to image quality. If that's what he's planning on doing then the XDCAM 422 codec makes a lot of sense.

We really need to know more about his plans before we can give good advice. I too was probably jumping the gun without first asking exactly what his workflow is going to be.

Bob.

Hey, Bob...

No, I didn't mean to imply (in either post) that his idea was silly. I totally missed the part about his original footage being HDV.

I fully understand his thinking... well sort of. The same applies to my thinking most of the time.

For example, how does Vegas (or any app for that matter), using the MXF 422 codec, take the camera original and "upgrade" the footage to a higher level? Where is the "extra" data coming from?

It's the same problem I have wrapping my head around the idea of shooting in 24fps and then having it shown on a TV at 30 fps. Where are the additional 6 frames--another 20%--coming from? I'm not being critical, I'm just not comprehending.

The extra data when you go from 4:2:0 to 4:2:2 is obtained by interpolation. You obviously gain nothing in the process apart from using up more disk space. The smoothing that the interpolation creates can make the result more visually appealing though. You can achieve much the same in Vegas using the chroma smoothing FX.

On the other hand though codecs like mpeg-2 can discard data that they cannot fit into the bandwidth. You re-encode that output and even more gets lost and the artifacts build up and can become very ugly. If you used exactly the same mpeg-2 codec but at a higher bitrate as the intermediate the theory is that no more data gets discarded and the image holds up very well.

Bob.

My camera is a Sony Z1 HDV model. I chose this format over the EX1 that was a similar price because I do documentary style work and tape is more practical for this application. For example, I am hoping to do a trip to Africa in August. During three or four weeks of shooting I will go through. Twenty or thirty tapes. In this sort of case in order to use an Ex1. You would need a laptop, reliable power every night. At least two portable hard drives to transfer the footage to, and an hour or so of extra time each night for transferring and backing up footage. That is why I'm using hdv.

In this case I won't be doing the editing, but quite often I am. Vegas can only handle a limited number of long GOP clips at once. In my experience, you are already in trouble by the time you are on your second tape. It is not the amount of recorded time that causes problems. It is the number of clips.

If you change everything into Cineform the problem goes away and you can have as many clips on the timeline as you want. If you stick with long GOP, Vegas needs to buffer the beginning and endings of all those clips. The problem with transcoding everything into Cineform is that with twenty plus tapes, you are looking at one heck of a lot of hard disk space by the time you back everything up.

The most practical way to deal with this is to smartrender the source HDV footage into large sections. Often the best way is to render large HDV sections with names like "tape1". "Tape2". etc. A better option is to use names like "location name 1" or "Tim Jones Interview". Each time you smartrender out one of these sections you are trimming away the junk.

Now is when you run into one of the major weaknesses of HDV. That is that while the video will smartrender, the audio will not. You can get around this by rendering wav or flac audio files that corrospond to the video files, but it is akward to use them later when you are dealing with 20 hours plus of footage plus separate corresponding audio files.

That is why .mfx is such an intriguing format for me. It smart-renders, has uncomressed audio, and yet according to another current thread, holds up even better than Cineform after multiple rerenders that aren't smart-renders.

Hence my original question: given that I am starting out with hdv footage. It seems to me that the 35mbps 1440x1080x8bit version of the XDCAM .mfx format would be the smartest since many of the extra bits. (Out of th 50mbps highest quality option) would be wasted on interpolated pixels and color space that isn't really there in the source footage.

"During three or four weeks of shooting I will go through. Twenty or thirty tapes. In this sort of case in order to use an Ex1. You would need a laptop, reliable power every night. At least two portable hard drives to transfer the footage to, and an hour or so of extra time each night for transferring and backing up footage."

Sorry, but I'll have to disagree. You can easily shoot on SDHC cards. Issue solved.

I just saw the SxS to SDHC adapter not too long ago. Yeah, you could have a bunch of SDHC cards and one of those adapters couldn't you. I wish I'd had an inkling that this sort of thing was a possiblity back when I bought my Z7. At the time, I was looking at $800 8gig cards and could see no possible way to use it on an extended documentary shoot.

I really can't complain because the Z7 image is just stunning, but if I had to do it again, I'm sure I'd go with the EX.