Re: Currently-Available Highest-Quality Linear PCM Video?


"Radium" <glucegen1@xxxxxxxxxx> wrote in message
news:1161215134.919468.300660@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Note that the sentence "there is uncompressed PCM for video"
does not equate to "all digital video is PCM" or "PCM is required
for high-quality digital video."

I am well aware of that. Most digital video uses -- MPEG-layer or some
other form of compression -- not linear PCM. I don't know why?

PCM is simply one possible encoding
and transmission scheme, nothing more - and it is not the one used
in most digital video systems.

Why isn't linear-PCM used in video?

Why do you think it should be? What advantage would it bring?
What costs (either in actual $ costs or performance) would using
linear PCM require?

1920 pixels/line x 1080 lines/frame x 30 frames/sec (it's interlaced)

Note that if you work the units out as well, it comes out in terms
of pixels/second, exactly as it should.

Are you sure that isn't that the bit-rate? There is a world of
difference between bit-rate and sample-rate.

How many bits do you think are contained within each
"pixel"? What do you think the word "pixel" means, and
how is it distinguished from "sample" in the context of
digital imaging?

For example, CD audio has a sample rate of 44,100 hz but a bit rate of
1,411,200 bps.

If you divide 1,411,200 by 44,100, what number do you
get? What is the significance of this number?



It can be; it simply doesn't HAVE to be, so there is no need
to be dragging that question in at this point.

Linear-PCM doesn't have to be used but what harm is caused by using it?

Answer the above questions, and then you'll have your own
answer to this one. Why are you so hung up on "linear PCM"
as opposed to any of several hundred (at least) other possible
encoding schemes?

Bob M.


.

Relevant Pages