[opendtv] Re: 1080p @ 60 is Next?
- From: dan.grimes@xxxxxxxx
- To: opendtv@xxxxxxxxxxxxx
- Date: Thu, 17 May 2007 09:17:35 -0700
Call me nuts and unscientific, but when I compare 1080i and 720p original
source material from a camera of a static scene on two monitors side by
side, I prefer the 1080i at almost any distance for various reasons
including perceived sharpness.
When I compare 1080i source material off of a HDCam tape and a 720p source
off a DVCProHD, I can tell the difference across the studio floor. The
1080i wins hands down, but not necessarily based on resolution. Color (and
especially color resolution) has a lot to do with it.
When I compare 1080i and 720p encoded in JPEG2000 at 300Mb/s, the 1080i
wins for numerous reasons (this was projected on 35' screen, so resolution
was certainly a factor).
But, when I compare 1080i material and 720p material from transmitted
sources (OTA, DBS, Cable, etc.), the 720p format wins everytime at any
distance, independent of the screen resolution (that is 720 or higher) and
especially if motion is involved. I say at any distance (within reason)
because the artifacts are so gross that pixels don't matter; I'm seeing
blocks.
My point? It doesn't really matter how high the resolution one produces in
when the transmission medium can't handle it. The transmission compression
is clearly the limiting factor so one might as well down convert (if
necessary) to make the best use of the transmission format.
However, broadcast is not the only application involved. I don't remember
what format/resolution the Met is using for transmission (I know they are
using 1080i for production), but clearly this is a case where resolution
matters, and the transmission format is better to make use of it. I am
doing a similar thing where a scene is recorded and played back on a 35'
screen for an auditorium full of people. Here, clearly, resolution makes a
difference.
I would like to build a case why 1080p@60 makes sense to me. I believe
this format utilizes the better spatial and temporal resolutions of each
format. I believe compression algorithms do better with progressive
scanned material. I believe oversampling has always been a preferred way
of producing, allowing for a better end result after processing, ESPECIALLY
when downconverting to a lower resolution. And I believe archiving in a
higher format is beneficial (clearly, if we had the choice between two
recordings of a historical scene, we would use the best looking recording
in the production.) If one produces in 1080p@60, the final product can be
more easily downconverted and/or compressed into the final transmission
medium, all the while preparing for a future transmission medium that is
better. I would even venture to say that producing in 4:4:4 would have
great merit in the production chain.
To me, the decision whether to produce in 1080p@60 or one of the other
formats is only based on the cost/benefit ratio. And since the production
equipment is not even available (that I know of), it is currently too
difficult (although not impossible) to do so. And it is impossible to do
so in any live format.
So in conclusion, I believe producing in 1080p@60 today does have a benefit
to the viewer today and tomorrow, no matter what format they are viewing in
their home. Unfortunately the argument is moot since one can't produce in
that format anyway. But I do think it would be beneficial to develop
equipment to do so.
Dan Grimes
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