The genesis for this technique came from
a recent client installation in New York City where we were experimenting
with different codecs to see which would be the best to use for
high-quality off-line editing.
And, during some recent editing, I'd
become very dissatisfied with the low-res images a CinéWave
card was creating. So, I decided to go right to the source and
talked with Andrew Baum, product manager of CinéWave at Pinnacle Systems, and Clark Simpson, Manager,
AJA Technical Support, about how to choose the best codecs
for capturing video.
What I learned was that while there is
no single perfect codec solution for everyone, it is possible
to make some fairly clear recommendations.
To get us started, a codec is software
that converts the signals on your video tape into digital data
the computer can read. The better the codec, the higher-quality
images it creates.
Some tape formats, like DV, are already
digital. In this case, when you capture a DV tape, you are simply
transferring the digital data on the tape to the computer. However,
when you capture an analog tape, such as Beta SP, you need to
convert the signal from analog to digital. Because you are actually
converting your video and audio information, the quality of the
codecs you use directly affects the quality of the picture.
Here's the key question I asked both
Andrew and Clark: When capturing SD video, what codec should
you use when you want the best quality for final on-line? And,
secondarily, what codec should you use when you want the smallest
possible file size with the best quality for off-line work?
For final on-line quality work, there
are five choices
- Digital 10-bit (i.e. DigiBetacam)
- Analog 10-bit (i.e. Beta SP)
- Analog 8-bit (i.e. Beta SP)
- DV (MiniDV, DVCPRO-25, and DVCAM)
Since DigiBeta, DVCPRO and DV are all
digital formats, your capture card (or FireWire) doesn't have
an impact on the quality of your picture. Instead, you are simply
transferring the digital bits from your camera to the computer.
In this case, you'll get the highest quality by staying in the
- For DigiBeta, use SDI (Serial Digital
Interface) set to 10-bit quality
- For DVCPRO-50, use the appropriate Apple-supplied
DV50 codec (NTSC or PAL)
- For DV, use the appropriate Apple-supplied
DV codecs (NTSC or PAL)
Since DigiBeta, DVCPRO and DV are digital
formats, image quality is determined when you shoot, rather than
when you capture. So, for this rest of this article, we'll focus
on the analog side of the video house.
When capturing analog video, however,
your codec choices become much more numerous.
Use the Apple-supplied uncompressed codecs
Use vendor-supplied proprietary codecs
Both Clark and Andrew agree that the
Apple codecs offer excellent quality, with the advantage that
clips captured using these codecs can be played on any system
that supports QuickTime on the Mac.
Deciding between 10-bit and 8-bit
Generally, given good lighting, good
lenses and a photographer that knows how to focus, 10-bit provides
the best quality, followed by 8-bit.
If your pictures include lots of compositing,
green or blue screen, graphics with gradients, 10-bit is worth
it. Even if your pictures start out in an 8-bit environment --
such as Beta SP or Beta SX -- editing using a 10-bit sequence
will still be worth it.
If your pictures don't include a lot
of graphics, compositing or effects, 8-bit is fine.
Capturing at full "on-line"
If capturing at the highest-possible
quality is your goal, your choices depend upon which capture
card you own. However, in all cases, 10-bit video looks better
than 8-bit. But, 10-bit files are about 20% bigger than 8-bit
files. (On a CinéWave it's 27 MB per second for 10-bit,
versus 21 MB per second for 8-bit.)
If you use a CinéWave, Andrew
recommends the following: "While the Apple uncompressed
codecs look very good, and are fully supported by CinéWave,
the advantages to using the CinéWave codec are the following:
- Better chroma filtering with options
for both graphics in the RGB color space and video in the YUV
- Control of the Gamma settings so that
the appropriate Gamma levels are used
- Support for High-Definition video (the
Apple codecs are only SD)
- Better quality
- Real-time effects
"Plus, the real benefit is that
CinéWave supports multiple codecs in the same sequence
with layers and effects all in real-time," says Andrew.
"One of the major advantages of CinéWave is that
we can capture and playback in any of the following formats in
the same sequence in real-time and with real-time effects between
and on top of the clips."
- 8-bit uncompressed
- True 10-bit uncompressed
- 16-bit uncompressed
- Animation codec
- RGBA with embedding moving alpha
- RGBA with graphic
- Apple LiveType
So, I went off to a client's to test
all this interoperability and discovered a BIG "provided..."
If you own a CinéWave card and need to integrate all these
different codecs on one timeline, you also need to buy the CinéWave
RT Pro real-time option. This used to be $2,500, but has recently
been reduced to $995, according to Andrew. Without the CinéWave
RT Pro option, CinéWave only supports one codec per timeline;
everything else needs to render.
The reason the CinéWave can handle
all this real-time codec integration is that it is using the
processing power in the CinéWave card, in addition to
If you are using a Kona card, Clark Simpson
recommends picking a capture format and sticking with it, "because
it is awkward to mix formats on the Timeline." The Kona
card uses drivers written by Black Magic, however, recently,
Kona and Black Magic parted ways so, in the future, the best
codec to use with a Kona will be the Apple uncompressed codecs;
both 8- and 10-bit.
While the Kona SD isn't as flexible as
the CinéWave in real-time effects, or in handling multiple
formats, it has a significant advantage when capturing video
for off-lining, which I'll discuss below. It also is significantly
less expensive than a CinéWave, while still providing
excellent image quality.
The AJA IO always feeds 10-bit video
to the computer. So, if you need to conserve file size, while
still maintaining "on-line" quality, use the Apple
codecs to transcode (i.e. convert) from the 10-bit video stream
to 8-bit or DV video. The only significant disadvantage to the
IO is that you can't connect both an IO and a DV deck; the IO
requires the full bandwidth of FireWire. However, it's easy to
add a FireWire switch to change from the deck to the IO and back.
So, what settings should you use?
CinéWave -- Targa Cine NTSC (or
PAL) YUV (10-bit)
CinéWave -- Targa Cine NTSC (or
PAL) YUV (8-bit)
Kona and IO -- Uncompressed 10-bit
Kona and IO -- Uncompressed 8-bit
If you need to move video files between
computers, use the uncompressed settings provided in the default
installation of Final Cut Pro.
Capturing for good quality, off-line
However, many of us work in an off-line
environment in order to save disk space and avoid overloading
the computer's CPU. Here, some interesting new choices have developed.
If you are using DV, stay with DV for
your off-line work. Don't use Offline RT; it causes far more
problems than it solves.
If you are using CinéWave, don't
use the TARGA Ciné YUV 25% (or 50%, for that matter).
The video is ugly and the file sizes are too big. Instead, Andrew
recommends you transcode all your captures into DV25 (using TARGA
Ciné YUV to DV). Your file sizes will be half the size
of the TARGA 25% quality with DV25 and your image quality will
(DV25 is about a seventh the size of
uncompressed 10-bit video.)
It is also possible to use PhotoJPEG
with the CinéWave card for off-line work. As Andrew explains:
"For the full resolution PhotoJPEG
mode, the CinéWave has the exact same flexibility [as
the Kona SD] on PHOTOJPEG capture. You can capture PhotoJPEG
at variable rates, and if you choose, you can record PhotoJPEG
at even lower data rates, so it is every bit as flexible as Kona
SD on PhotoJPEG data rates.
It's important to note that perceptually,
PhotoJPEG at around 5 MB/sec is about the same as DV at 3.6MB/sec,
so for a nearly equivalent image, it's better to use DV as it
will have a lower data rate. However, to push Offline recording
to lower data rates, CinéWave can also be set to capture
PhotoJPEG, and PhotoJPEG in the 1-2 MB/sec range isn't too bad.
Of course you can mix it with all of the other formats we support
in the same timeline."
If you are using Kona or AJA IO, you
can use DV, but, personally, I like the Photo-JEPG codec set
to 75% quality. File sizes are about a third the size of DV and
the image quality is amazing. It offers the best balance between
image quality and file size.
After you capture, be sure to set your
sequence settings to match the capture codec you are using, otherwise
you'll need to render all your files. (Unless, of course, you
are running the CinéWave RT Pro option.)
About the Companies
Pinnacle Systems [www.pinnaclesys.com] is a leading supplier of high-quality digital video creation and distribution tools since 1986. Pinnacle Systems has won nine Emmy Awards for its work in computer-based video productions, with products that range from consumer home video editing and DVD authoring software to broadcast servers and news production solutions. Pinnacle is best known to Final Cut users as the developer of the CinéWave series of products.
Since 1993, AJA Video [www.aja.com]
has been a leading manufacturer of professional digital video
solutions for the professional broadcast and post-production
markets. AJA's desktop video products include uncompressed FireWire
and PCI based QuickTime audio/video interfaces for both Standard
and High Definition video. AJA is best known for its Kona capture
cards and IO FireWire-based interface box.
This tip is from "Larry's FCP
Newsletter," a very cool FREE monthly Final Cut Pro newsletter -- subscribe at Larry's website: www.larryjordan.biz. 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 and Producers Guild.
Text copyright 2004, by
Larry Jordan. All rights reserved.