Tortanick
12-24-2006, 04:15 PM
Found this great article about vista DRM:
http://www.cs.auckland.ac.nz/~pgut001/pubs/vista_cost.txt
"It is recommended that a graphics manufacturer go beyond the strict letter
of the specification and provide additional content-protection features,
because this demonstrates their strong intent to protect premium content".
This is an exceedingly strange way to write technical specifications, but is
dictated by the fact that what the spec is trying to achieve is fundamentally
impossible. Readers should keep this requirement to display appropriate
levels of dedication in mind when reading the following analysis [Note A].
Alongside the all-or-nothing approach of disabling output, Vista requires that
any interface that provides high-quality output degrade the signal quality
that passes through it. This is done through a "constrictor" that downgrades
the signal to a much lower-quality one, then up-scales it again back to the
original spec, but with a significant loss in quality. So if you're using an
expensive new LCD display fed from a high-quality DVI signal on your video
card and there's protected content present, the picture you're going to see
will be, as the spec puts it, "slightly fuzzy", a bit like a 10-year-old CRT
monitor that you picked up for $2 at a yard sale. In fact the spec
specifically still allows for old VGA analog outputs, but even that's only
because disallowing them would upset too many existing owners of analog
monitors. In the future even analog VGA output will probably have to be
disabled. The only thing that seems to be explicitly allowed is the extremely
low-quality TV-out, provided that Macrovision is applied to it.
Amusingly, the Vista content protection docs say that it'll be left to
graphics chip manufacturers to differentiate their product based on
(deliberately degraded) video quality. This seems a bit like breaking the
legs of Olympic athletes and then rating them based on how fast they can
hobble on crutches.
Ok I'm gonig to stop posting quotes now, lets just say its a good article.
VIVA LA LINUX!
http://www.cs.auckland.ac.nz/~pgut001/pubs/vista_cost.txt
"It is recommended that a graphics manufacturer go beyond the strict letter
of the specification and provide additional content-protection features,
because this demonstrates their strong intent to protect premium content".
This is an exceedingly strange way to write technical specifications, but is
dictated by the fact that what the spec is trying to achieve is fundamentally
impossible. Readers should keep this requirement to display appropriate
levels of dedication in mind when reading the following analysis [Note A].
Alongside the all-or-nothing approach of disabling output, Vista requires that
any interface that provides high-quality output degrade the signal quality
that passes through it. This is done through a "constrictor" that downgrades
the signal to a much lower-quality one, then up-scales it again back to the
original spec, but with a significant loss in quality. So if you're using an
expensive new LCD display fed from a high-quality DVI signal on your video
card and there's protected content present, the picture you're going to see
will be, as the spec puts it, "slightly fuzzy", a bit like a 10-year-old CRT
monitor that you picked up for $2 at a yard sale. In fact the spec
specifically still allows for old VGA analog outputs, but even that's only
because disallowing them would upset too many existing owners of analog
monitors. In the future even analog VGA output will probably have to be
disabled. The only thing that seems to be explicitly allowed is the extremely
low-quality TV-out, provided that Macrovision is applied to it.
Amusingly, the Vista content protection docs say that it'll be left to
graphics chip manufacturers to differentiate their product based on
(deliberately degraded) video quality. This seems a bit like breaking the
legs of Olympic athletes and then rating them based on how fast they can
hobble on crutches.
Ok I'm gonig to stop posting quotes now, lets just say its a good article.
VIVA LA LINUX!