I have been somewhat vocal in discussing some of the problems in working
with HDV. However, there are lots of different opinions on this point.
Recently, Iain Anderson gave me permission to reprint
this:
I heartily recommend editing HDV footage natively. A number of people
have expressed the opinion that long-GOP MPEG footage is inherently
hard to work with. It's not -- it's very much the same as editing with
DV, and Unlimited RT works just as well. You certainly don't need to
render every edit.
I recently cut a short film in HDV on a MacBook Pro, and it was a
painless experience which produced high quality results. I used FCP6,
which did make the process somewhat easier. As the film was part of
the 48 Hour Film Project, I had less than a day for editing and delivery
to mini DV tape. A shame to see all the HD quality disappear at the
end, but the process worked well.
The advantages of HDV:
1. No extra hardware needed to import footage. Any machine capable
of running the current version of Final Cut Pro can cut HDV. It's painless
to edit, and while effects can take time to render, the vast majority
of effects work with Unlimited RT just like SD footage. The only issue
I had with rendering was when overlaying several streams of video with
feathered cropping.
2. No transcoding needed. You can't get better quality by recompressing.
In fact, you can make it much worse. DVCPRO HD, for NTSC frame rates,
uses a different frame size (1280x1080) to HDV (1440x1080). If you
have to transcode, ProRes 422 or AIC are better choices.
3. Low data rate. It's HD with the DV space/data rate requirements
of ~13GB an hour, while transcoding at least triples your data rate
and space requirements. We've just about hit the point where you'll
be able to keep all the HDV you ever shoot permanently online by buying
a cheap hard drive every few years.
4. Easier media management. When you capture HDV natively, footage
is automatically split into separate files based on when you started
each recording session. No more huge files from students capturing
files in hour-long blocks and easy deletion of bad footage.
5. Near-instant HD screeners. HDV footage needs no recompression to
go onto an HDDVD, and every current Mac can play HD-DVD's made with
DVD Studio Pro burnt to regular DVD discs. This is incredibly powerful;
it's about the only way to deliver HD footage without expensive hardware.
You will need to conform HDV footage to do this, however, bringing
us to...
The drawbacks of HDV:
1. The 4:2:0 colors. Not ideal, but the same as PAL DV. If you've
shot in HDV, the damage has already been done, but it's really not
that bad. The latest Sony XDCAM EX uses the same colour space. This
doesn't have to limit the quality of your colour correction, though
-- see 3 below.
2. Long conform times when finished. This is an issue only when you've
finished your edit and need to export back to HDV. The conforming process
takes about as long as a slow render, say, a few times real time. If
you're not finishing to HDV, not a problem. While you're editing, not
a problem.
3. Recompressing to HDV can introduce artifacts and is slow. True
if you're colour correcting or applying other filters, but there's
a fantastic solution built in to FCP 6. Choose Sequence Settings, and
look under the Render Control tab. Change the render codec to Apple
ProRes 422. Specifically for HDV and XDCAM HD/EX, this feature renders
effects to ProRes instead of HDV. No quality loss, no extra time spent
recompressing during editing.
For Larry Jordan's (slightly differing) opinion, click
here.
But don't miss Graeme Nattress's comment on Larry's page:
[Should you convert HDV to DVCPro HD?] No. Never! Why? Adding compression
on top of compression is just bad. DVCproHD is way too compressed.
It's full of artifacts even straight of a varicam. To add that compression
on top of HDV just makes a mess.
Answer - edit HDV native - it's easy on a decent mac, and then
just change the compression right at the end of editing to "uncompressed",
do a final render before going out to master tape. Again, you'd
never use HDV as a master - even one compression back to HDV looks
awful.
Only use DVCproHD if that's what you shot, or are going back to DVCProHD
tape. If you're recording live from SDI, uncompressed HD, or Photo
JPEG 75%, are much superior.
HDV isn't perfect, but I'm constantly amazed by the quality I get
out of my HV 20 for the price and how easy it is to deal with. It's
possible that the poor opinion of HDV PQ in the industry is partly
due to the PAL/NTSC divide. Here in Australia, we only have to record
25 frames per second at the same data rate that NTSC models have to
record 30 frames. Those 20% extra frames per second might be pushing
the compression just a bit too far.
Larry Jordan is a post-production consultant and an Apple-Certified Trainer in Digital Media with over 25 years experience as producer, director and editor with network, local and corporate credits. Based in Los Angeles, he's a member of both the Directors Guild of America and the Producers Guild of America.
The information in this article is believed to be accurate at the time of publication. However, the author assumes no liability in case things go wrong. Please use your best judgment in applying these suggestions.
The opinions expressed in this article are solely those of the author. This newsletter has not been reviewed or sanctioned by Apple or any other third party. All trademarks are the property of their respective owners and are mentioned here for editorial purposes only.
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