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Uncompressed Digital Video vs. Uncompressed Digital Audio

R

Radium

RGB is analog, not digital, so this is not a reasonble question.

Bob Myers says in http://groups.google.com/group/
sci.electronics.basics/msg/bbad436d1cb6cd02?hl=en& :

"RGB simply means "red, green, and blue" video - it clearly can be
represented in either analog or digital form."

Not trying to side with either party or start a battle, sorry if it
seems that way.
 
R

Richard Crowley

"Radium" wrote ...
Why is it that uncompressed digital video can have so many format
[such and RGB as well as linear PCM]

"RGB" and "linear PCM" are not two different "format"s.
but uncompressed digital audio
can only have one format -- PCM??

Here we go again. Maybe you better define what YOU
mean by "format"? Do you mean encoding scheme?
Do you mean codec? etc. etc. etc.

Else you are likely to start another pointless thread
where people argue about what you mean. It would
also be helpful to reveal WHY you are asking so maybe
we can figure out WHAT you are asking.
 
R

Radium

It would
also be helpful to reveal WHY you are asking so maybe
we can figure out WHAT you are asking.

What is the most common type of uncompressed digital video? Is it a
type of PCM format? If not, what is it and why isn't PCM video -- like
the PCM audio in CDs -- used?

Basically, I am looking for the "video equivalent" of CD audio.
 
M

Mr.T

Radium said:
Seems like all of them are PCM.

If you actually knew what PCM was the acronym for, you might realise that
Arny already mentioned other schemes.
Just because they are not as common, doesn't mean alternate schemes do not
exist.

MrT.
 
R

Richard Crowley

"Radium" wrote ...
Seems like all of them are PCM.

That is because "PCM" is an archaic name for "digital".
(PWM/PDM were similar archaic terms/schemes.)
It was coined at Bell Labs when digital audio was first
implemeted as a lab experiment. It has no practical
meaning today and causes more confusion than just
using the proper modern term.
 
M

Mr.T

Radium said:
Basically, I am looking for the "video equivalent" of CD audio.

It would be nice if there was one single video format as common as CD audio
I guess. The nearest equivalent would obviously be standard DVD, MPEG-II,
but unfortunately you still have the country dependant format variations for
frame size and frame rate etc.

However even PCM audio you first asked about, comes in a lot more formats
than 16/44.1 CD audio you now mention, so they are not that dissimilar after
all.

MrT.
 
M

Mr.T

Richard Crowley said:
That is because "PCM" is an archaic name for "digital".
(PWM/PDM were similar archaic terms/schemes.)

Not so. They are all more specific descriptions of the digital coding used.
"Digital" is simply a more generic term.
It's the same as saying FM and AM are both analog "radio broadcast" methods.
Some people need to understand the difference, and some don't care.

MrT.
 
R

Radium

It would be nice if there was one single video format as common as CD audio
I guess. The nearest equivalent would obviously be standard DVD, MPEG-II,
but unfortunately you still have the country dependant format variations for
frame size and frame rate etc.

Um, MPEG is compressed. I was looking for uncompressed digital video.
However even PCM audio you first asked about, comes in a lot more formats
than 16/44.1 CD audio you now mention, so they are not that dissimilar after
all.

Yeah, these days :). There's CDR, CD-RW, CR+RW. I was taking about the
common audio CDs used in the 80s. Any *uncompressed* digital video
equivalent of that good ole' 80s CD audio?
 
M

Mr.T

Radium said:
Um, MPEG is compressed. I was looking for uncompressed digital video.

The nearest would probably be the mini DV camera format then. They're pretty
common.

MrT.
 
R

robert bristow-johnson

Would you mind naming one?

how about the one named "Radium is just a troll jerking our chain"
a.k.a. Sony SACD. it's not PCM. sometimes it's called "PDM".

you must really think other people are stupid when it is you that is.

r b-j
 
R

Richard Crowley

What is the most common type of uncompressed digital video?

What does "type" mean in your world?
By "common" do you mean historic or current?
Is it a type of PCM format?

It is likely not defined that way because PCM is usually
used to refer to audio, not video.
If not, what is it and why isn't PCM video -- like
the PCM audio in CDs -- used?

What does "PCM video" mean in your world? Does it
just mean "digital video"?
Basically, I am looking for the "video equivalent" of CD audio.

D1 & HDCAM SR were uncompressed component digital video formats.
D2 and D3 were uncompressed composite digital video formats.
All were tape formats, and none was terribly popular nor
did they last very long.

There are some high-end schemes for recording uncompressed
video used in digital cinematography. I believe they are all
hard drive-based, not tape or optical.

The SDI digital video interconnection scheme used in
broadcast facilities has at least one mode that will
transmit uncompresed (4:4:4) video.

Putting true 4:4:4 uncompressed video on a 4.7 GB DVD
would give you about 4-5 minutes of playing time. (Assuming
you could spin the disc fast enough to read the data in real-
time) Perhaps that is why it never caught on. :)
 
R

robert bristow-johnson

What is the most common type of uncompressed digital video? Is it a
type of PCM format? If not, what is it and why isn't PCM video -- like
the PCM audio in CDs -- used?

the difference between those different video compression formats is
roughly analogous to the difference in the various audio compression
formats that you claim are "all PCM". so i guess all video is PCM,
from your definition.
Basically, I am looking for the "video equivalent" of CD audio.

like VHS? or, maybe if you look hard, Beta-max?

r b-j
 
R

Richard Crowley

"Radium" wrote ...
Um, MPEG is compressed. I was looking for uncompressed digital video.


Yeah, these days :). There's CDR, CD-RW, CR+RW.

CDR, CD-RW, CR+RW are writing formats. They have nothing
to do with audio except that one of their many uses is to
make either data discs with audio files on them, or to burn
"Red Book" audio CDs.
I was taking about the common audio CDs used in the 80s.

The "common audio CDs" used today are identical to the ones
from the "80s". Do you think there is some difference?
Any *uncompressed* digital video equivalent of that good
ole' 80s CD audio?

Certainly not in the consumer arena and very rare in the
professional one.
 
R

Richard Crowley

"Radium" <wrote...

The nearest would probably be the mini DV camera
format then. They're pretty common.

DV (and mini-DV and DVCAM and DVCpro25)
are compressed 5:1
DVCpro50 is compressed 2.5:1
 
R

Richard Crowley

...

Not so. They are all more specific descriptions of the digital coding
used.
"Digital" is simply a more generic term.
It's the same as saying FM and AM are both analog "radio broadcast"
methods.
Some people need to understand the difference, and some don't care.

Thanks for making my point.
 
R

Radium

"Radium" wrote ...

Certainly not in the consumer arena and very rare in the
professional one.

How do these video discs looks like? Are they bigger than CDs? Do they
use uncompressed digital video? If so, where could I possibly find
these treasures?
 
R

Radium

Putting true 4:4:4 uncompressed video on a 4.7 GB DVD
would give you about 4-5 minutes of playing time. (Assuming
you could spin the disc fast enough to read the data in real-
time)

Hm. Maybe using a bigger disc [about the size of 33-speed phonos] and
400 nm recording/playback lasers [instead of the dirty old red lasers]
would solve the above problems.
 
R

Richard Crowley

"Radium" wrote ...
How do these video discs looks like? Are they bigger than CDs? Do they
use uncompressed digital video? If so, where could I possibly find
these treasures?

Sony XDCAM HD. Don't try to read the price while standing.
 
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