[opendtv] Re: Video compression artifacts and MPEG noise reduction

  • From: "Manfredi, Albert E" <albert.e.manfredi@xxxxxxxxxx>
  • To: <opendtv@xxxxxxxxxxxxx>
  • Date: Mon, 16 Jun 2008 14:15:23 -0400

Kon Wilms wrote:

> Let's also abandon cars and bring back the horse and
> buggy while we're at it.

Wrong analogy, but there actually is a very close car-related analogy.

In the mid 1970s, Michelin introduced a tire with ellyptical
cross-section, called the TRX. The goal was to create high pressure, low
aspect ratio tires, without introducing too much ride harshness. This
was to provide better directional stability and fuel economy. Stresses
were supposed to be better distributed throughout the sidewall.

Because the cross section was ellyptical, standard wheel rims could not
be used. The surfcaes of the rim that mate to the tire were not
parallel, as they are in normal wheels. So while they were at it,
Michelin introduced a wheel rim with metric dimensions. TRX tires were
specified all-metric. Such as, 220/55-390.

Great. So in order to benefit from this innovation, everyone would have
to change tires AND rims.

Instead what happened was that other tire companies managed to change
their sidewall designs in such a way as to offer high pressure, very low
aspect ratios (soon even less than the 65 and 55 ratios of TRX tires),
without having to use a different standard of rim design.

If you can get away with it, it's usually better to extend the existing
standard. If you can do it, it's far easier to tweak MPEG-2 than to
introduce a new codec, for existing, deployed broadcast applications.

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