Uncompressed Digital Video vs. Uncompressed Digital Audio

"robert bristow-johnson" <rbj@audioimagination.com> wrote in message 
news:1171338632.890944.87010@j27g2000cwj.googlegroups.com...

>
> 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.

Yes, and all your base are belong to us....;-)

Bob M. 

"Radium" <glucegen1@excite.com> wrote in message 
news:1171333565.064182.32600@v33g2000cwv.googlegroups.com...
> On Feb 12, 5:44 am, "Arny Krueger" <a...@hotpop.com> wrote:
>> 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."

Yes, I did say that, and it still holds true.  For instance,
the video going over the common DVI digital interface is
RGB in digital form.  The "VGA" connector (HD15)
carries RGB in analog form.  There are other examples
of each.

But to the original question -  PCM is far from the only
common format for uncompressed digital audio.  (For that
matter, simply  saying that a digital data stream is being
transmitted in "PCM" form says nothing about whether
the data in question is compressed or uncompressed.)

Bob M.

Bob M. 

On Feb 12, 7:46 pm, "Richard Crowley" <rcrow...@xp7rt.net> wrote:

> 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.

"Radium"  wrote ...
> On Feb 12, 7:52 pm, "Richard Crowley" wrote:
>> "Radium"  wrote ...
>> > 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.
>
> 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. 

"Bob Myers" wrote...
> "robert bristow-johnson" wrote ...
>> 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.
>
> Yes, and all your base are belong to us....;-)

An excelent summary of the troll.  :-))
I'm done. 

Richard Crowley wrote:

   ...

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

Does a troll's reason for posing a question really puzzle you?

Jerry
-- 
Engineering is the art of making what you want from things you can get.
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

"Richard Crowley" wrote ...
> "Radium"  wrote ...
>> On Feb 12, 7:52 pm, "Richard Crowley" wrote:
>>> "Radium"  wrote ...
>>> > 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.
>>
>> 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.

Of course, we have to wonder where "Radium" thinks he
can get access to any "uncompressed video". I seriously
doubt that he has ever seen it (or likely ever will in his
lifetime.)

Even if he had a means of recording "uncompresed video"
what is he going to use as a source?  And if he had a player,
where does he think he can get any "uncompressed video"
programming to play on it? 

(some groups removed)
robert bristow-johnson wrote:

(snip)

> 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.

I was wondering today why we call sound recordings in any format
audio, but only electronic image formats video?  Specifically,
as far as I know movies on analog film are not video, but the
sound track on analog film is audio.

For the original question, how about a lossless (such as LZW)
compression of digitized video?

-- glen

Richard Crowley wrote:

(snip)

> Of course, we have to wonder where "Radium" thinks he
> can get access to any "uncompressed video". I seriously
> doubt that he has ever seen it (or likely ever will in his
> lifetime.)

Hmmm, don't computer monitors display uncompressed video?
Every bit from the display memory goes into the ADC on
the output of the video card, and, as far as I know
through the DVI cable if you use that.

> Even if he had a means of recording "uncompresed video"
> what is he going to use as a source?  And if he had a player,
> where does he think he can get any "uncompressed video"
> programming to play on it? 

Well recording it is certainly a different question.

-- glen

Bob Myers wrote:

(snip)

> Yes, I did say that, and it still holds true.  For instance,
> the video going over the common DVI digital interface is
> RGB in digital form.  The "VGA" connector (HD15)
> carries RGB in analog form.  There are other examples
> of each.

I agree so far.

> But to the original question -  PCM is far from the only
> common format for uncompressed digital audio.  (For that
> matter, simply  saying that a digital data stream is being
> transmitted in "PCM" form says nothing about whether
> the data in question is compressed or uncompressed.)

Well, compressed video (and audio) is normally described by
the name of the compression method, at least for lossy
compression.  Since you don't get back out the same thing
that went in, that seems an important part of the description.

For lossless compression, I might say that you could still
call it PCM.  That is, the compression could be considered
part of the recording process.  (Assuming that the recording
process can still record a random bit stream.)

If you look too closely, you find that PCM isn't what goes
onto a CD, but the result of error correction block codes
and finally EFM to the actual pits on the disk.  Since that
is (normally) transparent as far as recording and playing
back a CD, it seems fair to describe a CD in terms of PCM.

-- glen