Archived from groups: rec.video.desktop (
More info?)
On Mon, 26 Apr 2004 14:49:20 GMT, Five <Niko@fiveminutesof_blank.com>
wrote:
>In article <sn7jc.40464$_L6.2360156@attbi_s53>,
>david.mccallUNDERLINE@comcast.net says...
>>
>> "Martin Heffels" <zurssryf@arjfthl.pbz (ROT13)> wrote in message
>> news:gn4p801gcfmheehnb9eibigiih34dr6622@4ax.com...
>> > On Mon, 26 Apr 2004 02:15:06 GMT, "tkranz" <tkranz@worldnet.att.net>
>> > wrote:
>> >
>> > >Does anyone have details on this rumor?
>> > Don't wet your pants yet ;-) It's HD-DV, or heavily compressed HD on
>> > mini-DV. Wonder why they didn't come-up with a model which can run the
>> > tape a double speed to have less compression.
Time -- this is a consumer format, not a professional format. The
adjustment was to change the compression, not the tape. Plain old
everyday broadcast ATSC is 19.4Mb/s in the USA, 24Mb/s in Japan and on
some satellite systems. So the 25Mb/s of plain old DV tape is a fine
match. It will support broadcast quality, IF your electronics are
capable of delivering broadcast quality.
And in fact, they aren't. The current HDV format, as I understand it,
cuts corners. The JVC camcorder, the first out (before they were
really trying to make this a standard) is doing 720/30p, which
requires half the bandwidth of the broadcast 720/60p format. So
they're far less aggressive on compress than broadcast. Same with
their interlaced format -- they're not actually recording 1920 pixels
in their 1080/60i format, but something less that'll be stretched to
1920 in post.
>> It's a consumer/prosumer camera. There are pro HD cameras available now.
>> It's just that you don't get pro at that price point.
Yup. And they have a vested interest in keeping the two separate.
>
>> I think it's a pretty cool development. People are making "movies" with
>> DV (also a consumer format, technically). I think the low end indi market
>> will eat this thing up if they give it a low enough frame rate.
They'd still like 24p rather than 30p I imagine, at least now.
Eventually, the theatres will all have digital projectors that can
handle multiple playback formats, and that won't matter so much. This,
too, may be a thing you don't see on the prosumer models for awhile.
Which is very silly -- any camera that can do 30p should be able to do
24p with a few software tweaks (maybe additional PLL settings in the
hardware). Not meaningful extra expense. The 24p vs. 30p would also
allow less aggressive MPEG-2 compression.
>The biggest problem I see is that it is HDV. That is
>taking a larger image, and compressing it more, and
>also doing so in a lossy format to the same size of
>capture media (DV tape).
Well, DV itself is a lossy format. This is too, being MPEG-2, but it's
also a more technologically advanced format than DV. There's no reason
this is a drop in quality from DV -- in fact, it should be much higher
quality. The real question is these first implementations: as anyone
like me who's made a few hundred VideoCDs and DVDs can attest, MPEG
compression is easy to do wrong. If their hardware isn't up to par,
that's where you'll have issues. It's dramatically more complex than
DV, there are many things that can go wrong.
>We should at least get a larger tape even if that
>requires us to use large DV tapes. IF size is of
>concern, then using a new formulated 8mm tape would
>offer longer potential run times due to the ability to
>put more tape in the shell.
I think it was simple: DV is here, it's designed for digital data, and
the bitrate exceeds that of broadcast. What would they do, for the
consumer, any differently.
You'll pay for this, but that's in post. MPEG-2 editing in HD is
possible; Vegas has done this for awhile, most of the high-end NLEs
are either supporting it or about to. But it's slow, and it's still
slow on the fastest PC you can get. It gets better if you can throw a
few PCs at it -- some of the NLEs initially targeting HD were designed
from the get-go to use a whole network for rendering.
>You are creating a new
>format, so why not a new tape size and formulation.
That's hard to do, and expensive. What if your new format fails --
just go ask any MicroMV owners if they're concerned about getting
tapes. You'd need at least 5x-10x the storage of the DV tape.
>Anyone viewimg a wide screen image would have a TV
>that can display progressive, so why not get rid of
>the interlace?
Most people like 1080i over 720p. Both are useful tools; a real
720/60p would be better for fast motion than 1080/60i. For anything
with detail, you'll want 1080i... and a monitor that's actually up to
that resolution. Most of the LCDs and many of the plasmas are just up
to the 720p level. So sure, you don't see any difference, but that's
the monitor, not the format.
The other reason: most networks want 1080i. Only ABC, so far, is
backing 720p.
>The size is easier to
>compress as well, so you loose less on the tape.
Real 1080/60i is only 12% larger than real 720/60p. Not a significant
difference.
>Yeah wide screen HD sounds great....on paper.
>I don't want it due to the problems after the cam.
>If you take a larger image, and compress it more going
>to the same size container, you will get something
>that is prone to all sorts of quality issues.
Again, depends on the camera. If you watched as much HDTV as I do, you
would not know it's not an intrinsic problem of the format: broadcast
HDTV eats DV for breakfast, lunch, and dinner. With acceptable HD
tools in place, I would think of going back to DV much as, being on DV
today, I think of going back to VHS: GOD NO, NOT THAT AGAIN!
>This is further complicated when you go to the editing
>stage. You cut it up, add effects, and transitions,
>and then finalize it again to the same format (re-
>compress it) remember it is a lossy format of higher
>loss than standard DV. This becomes your master, and
>then if you want to make DVD's, it gets compressed
>once again. I can not see how this will be better
>than what I already have...just wider.
Scaling down to HD, I very much doubt any compression artifacts remain
even as visible as DV compression artifacts do into DVD. For VHS-D,
I'm not sure you necessarily have to recompress at all, though you
probably do today, with conventional editing (unless you only cut on
GOP boundaries, you probably have to re-render it all). But that is
today -- as MPEG-2 becomes an editing format, apps will get better at
editing it.
I think the big fear would be CPU time -- when your image is 6x
larger, everything you do today will take 6x longer to do: rendering,
etc. Plus, MPEG-2 takes longer to decompress than DV, and it requires
lots of full-frame buffering (to deal transparently with B and P
frames). So it's likely to be more memory hungry as well.
>I think if they want to go wide, using the formats we
>have, a better option would be to go anamorphic.
That's widescreen, not HD. You can do that today, poorly, with nearly
any DV or Digital8 camera, and well with a handful. That's fine for
DVD. It's not even remotely a substitute for HD, if you really want
HD. Widescreen or standard, a 1080i picture is 6x larger than a DV
picture. That is significant.
>That
>way, you have a wide image without adding file size.
>This data can more easily go to 25meg formats.
16:9 has always been supported as part of the DV standard. Most people
have it today, though not always ideal implementations.
>So why not make an
>anamorphic lens specifically for the camera, instead
>of an after thought. That way you can eliminate the
>problems associated with zoom.
Why not just design-in a real 16:9 mode, and elimintate the
animporphic lens? That's the current trend, showing up already in a
few pro and prosumer cameras. It's the one actual advantage to video
of using these large pixel-count CCDs: you can crop in various ways,
combine groups of real pixels into DV pixels in different ways, etc.
>What would I like to see?
>I would like to see higher color signal processing
>Larger chip 1/2 or 2/3, and if you go natively wide,
>give it to me in 50meg format of your choosing, that
>is not compressed more than 5-1
Again, widescreen in standard definition has been around for years. It
doesn't change the DV format at all, only the human interpretation of
what's put on DV tape. HDTV is considerably more than just widescreen,
and it would need far more than a doubling of storage to do in a
DV-like format, rather than MPEG-2.
Dave Haynie | Chief Toady, Frog Pond Media Consulting
dhaynie@jersey.net| Take Back Freedom! Bush no more in 2004!
"Deathbed Vigil" now on DVD! See
http://www.frogpondmedia.com
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