Building Your Encoding Hardware - A Practical Guide to Video and Audio Compression - page 452

mixing desks will all likely support this. Many will also supply the 48-volt phantom
power required by some condenser microphones. Professional-grade equipment has latch-
ing XLR connectors. Balanced audio is not usually available on low-cost, consumer-
oriented computer I/O panels.

29.5.3 AES Digital Audio

TV studios will likely use balanced analog audio or AES digital audio. The benefit of
using AES is that up to 8 channels can be embedded in the SDI video signal, thus signif-
icantly reducing your cabling infrastructure and the costs of providing it. This is more
significant when routing via fiberoptic circuits, as it reduces the number of circuits and
transducers required. Circuits are expensive and the transducers cost many hundreds of
dollars each—and you need one at each end, on every circuit. Your alternative is multiple-
fiber circuits, which makes the cost of embedders and de-embedders very trivial by
comparison.

29.5.4 USB Audio

New equipment is being developed all the time. If your audio needs are modest, then
check out the M-Audio FastTrack interface. It's designed to be small and economical, and
it just plugs into an available USB port on your computer. This makes adding a good-quality
audio input to your system very easy.

29.6 Choosing an Operating System

An encoding platform can be built on any OS. Some operating systems lend them-
selves more easily to this than others because of the additional software that is installed
along with the OS. All of them are equally viable. It is just as realistic to build your sys-
tem on Mac OS X as on Linux, Windows, or any other mid-range system such as Solaris
or IRIX.
There may be some limitations on the support for a particular proprietary codec as a
result of marketing choices made by the supplier. Certain codecs may be built into the
operating system and therefore whatever tool you choose is irrelevant since the same
codec machinery is invoked each time. Some tools may provide more controls than others,
so it is worth investigating the alternatives. Getting something that is simple to operate
but not very flexible might be better than having to acquire in-depth training and knowl-
edge to get the best results out of a complex and detailed parameter set.

29.6.1 Building Around a Mac OS Architecture

On the Macintosh platform, the Sorenson Squeeze 4 product or the Popwire Technology
compression tools are the current state of the art. Discreet Cleaner may still be useful for
some work. The current version is getting a bit old now and has not been upgraded