What is the advantage of an "upconverting" player/recorder if
aruzinsky
With my upconverting Toshiba D-R560KU DVD recorder connected with both
HDMI and component cables to my Toshiba 32AV502R TV (720p), the
component connection gives a much better picture in that the edges are
sharper AND have less prominent halos. Of course, the 480p component
connection is interpolated inside the TV whereas the HDMI is not when
the recorder is set to 720p. But, at all recorder settings, the HDMI
connection gives a much worse picture than the component connection.
This also applies to direct feed from the recorder's tuner. Any
explanations?
Albert Manfredi
I think you are saying that the TV's image processor is better than
that of the DVD player. There's no reason to believe that such a thing
can't happen.
I've read many reviews of DVD players or other STBs, where the comment
was made that the component interface was better than the DVI or HDMI
interface. The truth of the matter is, those digital interfaces were
*NOT* introduced for reasons of image quality. In spite of the hype
from salesmen, the only motivation for introducing digital
uncompressed interfaces was to allow enryption in that STB-monitor
interface, to "close the analog hole," as they say.
Don't let them convince you otherwise. If the content owners get their
way, there won't even be an analog interface option in the future,
between STBs and monitors. And it won;t be for our benefit, you can be
sure of that.
Bert
aruzinsky
> On Oct 4, 1:09 pm, aruzinsky <aruzin...@general-cathexis.com> wrote:
>
> > the TV also has interpolation capability?
>
> > With my upconverting Toshiba D-R560KU DVD recorder connected with both
> > HDMI and component cables to my Toshiba 32AV502R TV (720p), the
> > component connection gives a much better picture in that the edges are
> > sharper AND have less prominent halos. Of course, the 480p component
> > connection is interpolated inside the TV whereas the HDMI is not when
> > the recorder is set to 720p. But, at all recorder settings, the HDMI
> > connection gives a much worse picture than the component connection.
> > This also applies to direct feed from the recorder's tuner. Any
> > explanations?
>
> I think you are saying that the TV's image processor is better than
> that of the DVD player. There's no reason to believe that such a thing
> can't happen.
>
With respect to general possibilities, yes. With respect to my case,
no. If my recorder's HDMI output is set to the native resolution of
my TV (720p), there should be no interpolation inside the TV, but the
picture is still bad. It is also bad at 480p, in which case, there
should be no interpolation inside my recorder. My immediate worry is
whether the bad picture is the fault of my TV or recorder. I prefer
that it is my recorder's fault because I will probably buy a new
recorder long before I buy a new TV. Meanwhile, I see no way of
easily determining which is at fault.
That said, my eyes and brain are much more sensitive to edge halos
than those of the average person because I have a lot experience in
still image processing. I doubt that most people would notice the
difference or mind.
>
> I've read many reviews of DVD players or other STBs, where the comment
> was made that the component interface was better than the DVI or HDMI
> interface. The truth of the matter is, those digital interfaces were
> *NOT* introduced for reasons of image quality. In spite of the hype
> from salesmen, the only motivation for introducing digital
> uncompressed interfaces was to allow enryption in that STB-monitor
> interface, to "close the analog hole," as they say.
>
> Don't let them convince you otherwise. If the content owners get their
> way, there won't even be an analog interface option in the future,
> between STBs and monitors. And it won;t be for our benefit, you can be
> sure of that.
>
> Bert
Thank you. Why no digital component connections, i.e., YCbCr instead
of YPbPr? Could that be done using the same component cable?
Albert Manfredi
> > I think you are saying that the TV's image processor is better than
> > that of the DVD player. There's no reason to believe that such a thing
> > can't happen.
>
> With respect to general possibilities, yes. With respect to my case,
> no. If my recorder's HDMI output is set to the native resolution of
> my TV (720p), there should be no interpolation inside the TV, but the
> picture is still bad. It is also bad at 480p, in which case, there
> should be no interpolation inside my recorder.
I'll bet you that in both of those examples, your DVD player or TV
need to resample the video. Most TVs sold as 720p, if you check the
specs, are actually 1366 X 768. Or 1024 X 768, with non-square pixels.
So whether the original signal is 720p or 480p/i, it would likely have
to be resampled at the monitor.
> My immediate worry is
> whether the bad picture is the fault of my TV or recorder. I prefer
> that it is my recorder's fault because I will probably buy a new
> recorder long before I buy a new TV. Meanwhile, I see no way of
> easily determining which is at fault.
I agree with your reasoning. I suppose a different HDMI source device
might be a good place to start, at least to see whether the halo
effect (which I assume is ringing) changes at all.
> Thank you. Why no digital component connections, i.e., YCbCr instead
> of YPbPr? Could that be done using the same component cable?
Well, that's what HDMI provides. It's carrying the MPEG-2 signal,
uncompressed, as YCbCr, in various optional modes (various numbers of
bits per sample, frames per second, and chroma bandwidth). MPEG-2
carries a compressed form of YCbCr. Or HDMI can also carry digital
RGB.
The component interface is the analog option, which is maybe still the
most bulletproof option there is. In the early days of HDMI, at least,
it was quite common to have two components that were supposedly HDMI,
but incompatible with each other. So the component interfaces were
always the sure bet for HDTV signals.
Bert
aruzinsky
Please, advise me on the following:
Do some hard drive recorders with digital tuners have the capability
to record and play back at the uninterpolated resolution of the
broadcast signal, e.g., 720p or 1080i? If so, is it possible to get
720p or 1080i over a component connection with such a recorder?
Albert Manfredi
> Do some hard drive recorders with digital tuners have the capability
> to record and play back at the uninterpolated resolution of the
> broadcast signal, e.g., 720p or 1080i? If so, is it possible to get
> 720p or 1080i over a component connection with such a recorder?
Well, at least one hard drive recorder should be capable of recording
off-air or cable HD signals. That's the TiVo HD recorder. Another
brand of HD recorder, Moxi, is only good for for cable (strangely
enough - they brag about no monthly fee as the TiVo requires, and yet
they force you to use cable).
The HD signal is available over the component interfaces. That's what
makes component interfaces different from the S-video or the composite
analog interfaces. Where the lesser analog interfaces give you a max
of about 5.6 MHz of luminance bandwidth, the component interface
should provide at least 25 MHz of luminance bandwidth, more or less,
which is what you need for 720p.
Here's the calculation:
720p has to draw 720 horizontal lines 60 times per second.
Each horizontal line consists of 1280 pixels. Worst case, alternate
pixels along each line are black and white.
Each horizontal line may therefore consist of 640 cycles, worst case.
(Consider a sine wave where the + peak is a white pixel and the - peak
is a black pixel.)
So, 640 cycles/line * 720 lines/frame * 60 frames/sec = 27.648 MHz.
Bert
aruzinsky
Thanks. I was looking/shopping at http://www.magnavox.com/pdf/le/H2160MW9_le.pdf
but it has a standard definition tuner. I suspect that when Blu-Ray
recorders with high definition tuners become available, there will be
hard drives installed in some, but, until then, most manufacturers
will drag their feet on hard drive recorders with HD tuners even
though it is technologically feasible now. I note, to my
disappointment, that my TV has output connections from its tuner.
I note that
http://www2.panasonic.com/consumer-electronics/shop/Video/DVD-Recorders-Players/DVD-Recorders/model.DMR-EZ28K.S_11002_7000000000000005702#tabsection
offers up to 1080 upconversion through its component output. Wouldn't
the component bandwidth strongly depend on the length of the cable?
While in school, I was disinterested in wave guide theory. But, it
seems intuitive that a 6" component cable won't attenuate a 1080
signal much (not that I know where to buy one).
Albert Manfredi
> Thanks. I was looking/shopping athttp://www.magnavox.com/pdf/le/H2160MW9_le.pdf
> but it has a standard definition tuner. I suspect that when Blu-Ray
> recorders with high definition tuners become available, there will be
> hard drives installed in some, but, until then, most manufacturers
> will drag their feet on hard drive recorders with HD tuners even
> though it is technologically feasible now.
I have the Philips equivalent of that DVDR/PVR, which is very
satisfying. Although not HD, as you point out. I'm afraid the HD PVRs
are mired in silly politics and are no doubt also being kept off the
market by various overly greedy interests, e.g. by the subscription TV
service providers who much prefer to rent their own to you.
> I note thathttp://www2.panasonic.com/consumer-electronics/shop/Video/DVD-Recorde...
> offers up to 1080 upconversion through its component output. Wouldn't
> the component bandwidth strongly depend on the length of the cable?
In practice, component outputs in the 12' length range work just fine.
I'm sure that you're right about extra long cables. The bandwidth has
to be up there close to 30 MHz and you should get as sharp an HD
picture as any HDMI would give you.
Bert