Image Processing Reference
In-Depth Information
You may find yourself taking a defensive position when discussing codec perform-
ance with other enthusiasts, especially when debating the merits of Windows Media over
Real Networks, QuickTime, or H.264. All of the codecs are now capable of delivering
good-quality content at useful bit rates. Content is carefully selected for demonstrations
that play to the strengths of one or another codec, so the argument is never settled as to
which is the best codec to use.
Very often the argument comes down to commercial matters such as licensing
fees and the potential audience size. Choosing Microsoft Windows Media is a very
easy decision to make but it is not always the optimum choice, nor are any of the
other proprietary codecs. Note that I said codecs and not players. Exchanging content
across different platforms is much easier with a mutually acceptable open-standard
codec.
Bit rate and file size constitute an altogether different argument and your choice
should be based on the desired performance at an available bandwidth. Here you would
be looking at the more modern codecs. H.264 is a very strong contender and my personal
view is that it will displace the others in the fullness of time, although there is no guaran-
tee of that.
In the end, there is no substitute for running evaluation tests of all your main con-
tenders. You may want to reduce the number of choices by looking at license fees and
audience figures before running lots of tests on codecs that you'll end up eliminating for
commercial reasons.
In order to test the codecs, you should assemble some representative sample video
content and subject all the candidate codecs to a comparative test. This is sometimes called
a “bake-off,” and magazines such as DV or Broadcast Engineering periodically feature the
results of these comparisons. Only after such testing will you have sufficient hard evi-
dence to make the best possible choice.
8.4.1
Choosing a Codec Is Not a Religious Pilgrimage
You must look deeper than just examining a list of specifications. You should spend
sufficient time running evaluations if you plan to “bet your company” or sink any
significant investment into this area. You must understand the commercial reasons
why the suppliers market these products and how your business fits into their overall
strategy.
You must also assess the risks involved if you build a business around a product or
service that is owned and survives only because another company chooses to sell a prod-
uct. They may not have heard of you or even be aware of your existence. Nevertheless,
they will make a commercial decision to upgrade, not upgrade, freeze, or cancel a product
on which you depend for your livelihood.
The three major players, Apple, Microsoft, and Real Networks, all contribute valu-
able technologies and ideas. Each approach is different from a technical point of view. At
times they are amazingly good at collaborating with one another and are a joy to work
with. At other times, it is a challenge to get the different technologies to work coopera-
tively in the same environment.
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