| Author |
Message |
T Shadow
Guest
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 Posted:
Sun Oct 30, 2005 1:07 am Post subject:
Re: Would I still be able to watch/record non-HDTV shows wit |
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"Grant Edwards" <grante@visi.com> wrote in message
news:11m4s9jaonhqg56@corp.supernews.com...
| Quote: | On 2005-10-28, T Shadow <knone@zilch.com.invalid> wrote:
Could you explain what you mean by this? I don't have any problems
capturing
analog with an HDTV Wonder. I don't consider 18% CPU usage "not doing a
very
good job".
It is compared to something like a PVR-250, which records MPEG2
with 2% CPU usage.
--
Grant Edwards
|
Using the CPU is not a problem. You could buy a DVR that wouldn't use any of
your CPU or HDD. How much do you want spend? I use my old computer for
ordinary tasks. It's already paid for.
Not having HDTV would be a problem.
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Grant Edwards
Guest
|
| Posted:
Sun Oct 30, 2005 1:20 am Post subject:
Re: Would I still be able to watch/record non-HDTV shows wit |
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On 2005-10-29, tim@nocomment.com <tim@nocomment.com> wrote:
| Quote: | Grant Edwards wrote:
On 2005-10-28, T Shadow <knone@zilch.com.invalid> wrote:
Could you explain what you mean by this? I don't have any problems capturing
analog with an HDTV Wonder. I don't consider 18% CPU usage "not doing a very
good job".
It is compared to something like a PVR-250, which records MPEG2
with 2% CPU usage.
Does a PVR-250 have HDTV capabilities?
|
Nope.
--
Grant Edwards grante Yow! I am having a
at CONCEPTION--
visi.com |
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Grant Edwards
Guest
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| Posted:
Sun Oct 30, 2005 1:22 am Post subject:
Re: Would I still be able to watch/record non-HDTV shows wit |
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On 2005-10-29, phil-news-nospam@ipal.net <phil-news-nospam@ipal.net> wrote:
| Quote: | So what is the reason for lack of compression hardware? That it is too
expensive?
|
It is if nobody want's it, and you get your lunch eaten by a
board without it.
| Quote: | As long as compression only needs to be done for analog SD,
which should be the case if the PC gets already-compressed
ATSC into the PCI bus, it should not be that expensive, and
should not be that hard to do in software (e.g. the PCI bus
does have sufficient bandwidth for raw uncompressed SD video).
|
No, it's not "hard" to do in software, but it does take about
200MHz worth of CPU.
| Quote: | Still, in a world where everyone chooses based on price,
tossing out as many features as possible to get the price at
the lowest point does tend to be the modus operandi of
consumer product design.
|
Exactly. 90% of prospective customers wouldn't even understand
what you said if you told them it had MPEG2 compression in
hardware.
--
Grant Edwards grante Yow! Are you still an
at ALCOHOLIC?
visi.com |
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Grant Edwards
Guest
|
| Posted:
Sun Oct 30, 2005 1:26 am Post subject:
Re: Would I still be able to watch/record non-HDTV shows wit |
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On 2005-10-29, T Shadow <knone@zilch.com.invalid> wrote:
| Quote: | "Grant Edwards" <grante@visi.com> wrote in message
news:11m4s9jaonhqg56@corp.supernews.com...
On 2005-10-28, T Shadow <knone@zilch.com.invalid> wrote:
Could you explain what you mean by this? I don't have any
problems capturing analog with an HDTV Wonder. I don't
consider 18% CPU usage "not doing a very good job".
It is compared to something like a PVR-250, which records MPEG2
with 2% CPU usage.
Using the CPU is not a problem.
|
Maybe not for you you. In my DVR, I ran a fanless CPU that was
the equivalent of about a 400MHz Pentium 1. There just no way
that CPU could capture/encode a recording stream while decoding
and displaying a playback stream. If you want to do it with
a big CPU (and listen to the damn fan while it's doing it),
that one choice. It's not what I chose.
| Quote: | You could buy a DVR that wouldn't use any of your CPU or HDD.
|
You can buy a DVR that has no CPU or HDD? I doubt it.
| Quote: | How much do you want spend? I use my old computer for ordinary
tasks. It's already paid for. Not having HDTV would be a
problem.
|
Not sure I follow...
--
Grant Edwards grante Yow! Kids, don't gross me
at off... "Adventures with
visi.com MENTAL HYGIENE" can be
carried too FAR! |
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T Shadow
Guest
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| Posted:
Sun Oct 30, 2005 1:37 am Post subject:
Re: Would I still be able to watch/record non-HDTV shows wit |
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"Jeff Rife" <wevsr@nabs.net> wrote in message
news:MPG.1dcc415e389ea91d98a0a9@news.nabs.net...
| Quote: | T Shadow (knone@zilch.com.invalid) wrote in alt.tv.tech.hdtv:
Could you explain what you mean by this? I don't have any problems
capturing
analog with an HDTV Wonder. I don't consider 18% CPU usage "not doing a
very
good job".
What codec are you using? What resolution, frame rate, and color depth
are
you capturing at? How many dropped frames do you have? Last, how good
is the quality compared to live TV?
Basically, unless a card has hardware encoding support (and I don't
believe
the HDTV Wonder does), you sacrifice something even if you have a very,
very fast CPU.
--
Jeff Rife |
Ok, been doing some testing. Evidently the 18% was from when I had a |
AIW128Pro in the computer and was still doing SVCD. Since then I've
installed an AIW9600XT as well as the HDTV Wonder and have been recording
DVD High with the ATI MPG2 codec. I've put off doing this test to decide
between Half DVD(352X480,8mb/s) and burning to DVD High(720X480,8mb/s)
since I wouldn't be doing the editing till cold weather anyway. CPU
percentages are 30 and 55 respectively for both cards. No dropped frames.
I can see a small difference in PQ between the two resolutions but not near
enough for me to be willing to use twice the space. For me it's going to be
Half DVD, when capturing analog, from now on.
With the best channel I could find on my system with a constant picture
quality I couldn't see any difference between the TV and the DVD High
capture. If I'm losing anything I can't tell it and can only wonder why the
CPU wouldn't be working harder if it wasn't. I've never seen any other
reference to modern CPUs not being able to do DVD High. Are you talking
about at the highest settings or real world use? Are you saving files at
these settings? How many minutes can you put on a DVD disc at that setting?
Could you point me to a webpage with this info?
I've never seen a setting for color depth in the codec. My computer
resolution is set to 32bit. |
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T Shadow
Guest
|
| Posted:
Sun Oct 30, 2005 1:52 am Post subject:
Re: Would I still be able to watch/record non-HDTV shows wit |
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<phil-news-nospam@ipal.net> wrote in message
news:dk0jfo21j5r@news4.newsguy.com...
| Quote: | On Fri, 28 Oct 2005 18:42:59 -0000 Grant Edwards <grante@visi.com> wrote:
| On 2005-10-28, T Shadow <knone@zilch.com.invalid> wrote:
|
|> Could you explain what you mean by this? I don't have any problems
capturing
|> analog with an HDTV Wonder. I don't consider 18% CPU usage "not doing a
very
|> good job".
|
| It is compared to something like a PVR-250, which records MPEG2
| with 2% CPU usage.
If it could do the job in 18% of CPU in the fastest available (today)
Intel CPU, and match the quality and effectiveness of real hardware
compression, I'd be interested in that software.
Hardware compression can, conceivably, do a number of the DCTs in parallel
to achieve greater throughput.
|
My % was off. See other post.
Not saying hardware compression is bad, just that it's an added cost if your
willing to use the CPU you already have. |
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Jeff Rife
Guest
|
| Posted:
Sun Oct 30, 2005 2:45 am Post subject:
Re: Would I still be able to watch/record non-HDTV shows wit |
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|
T Shadow (knone@zilch.com.invalid) wrote in alt.tv.tech.hdtv:
| Quote: | Ok, been doing some testing. Evidently the 18% was from when I had a
AIW128Pro in the computer and was still doing SVCD. Since then I've
installed an AIW9600XT as well as the HDTV Wonder and have been recording
DVD High with the ATI MPG2 codec. I've put off doing this test to decide
between Half DVD(352X480,8mb/s) and burning to DVD High(720X480,8mb/s)
since I wouldn't be doing the editing till cold weather anyway. CPU
percentages are 30 and 55 respectively for both cards. No dropped frames.
I can see a small difference in PQ between the two resolutions but not near
enough for me to be willing to use twice the space. For me it's going to be
Half DVD, when capturing analog, from now on.
|
That tells me the quality is pretty bad to begin with. Try capturing the
output of your DVD player using S-Video and see if "half" and "high" are
still close in quality. If they are, then I can pretty much say they both
suck without seeing either one.
| Quote: | I've never seen any other
reference to modern CPUs not being able to do DVD High.
|
Not all of us use "modern CPUs" in our DVRs. I have one machine with an
800MHz Pentium III, and used to use a 450MHz Pentium II.
| Quote: | I've never seen a setting for color depth in the codec.
|
Since you are using a DVD-compliant MPEG-2 codec, you won't get a choice.
On other codecs, you sometimes do, and reducing depth can save a lot of
CPU (and disc space).
--
Jeff Rife |
| http://www.nabs.net/Cartoons/FoxTrot/TransporterError.jpg |
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T Shadow
Guest
|
| Posted:
Sun Oct 30, 2005 11:03 am Post subject:
Re: Would I still be able to watch/record non-HDTV shows wit |
|
|
"Jeff Rife" <wevsr@nabs.net> wrote in message
news:MPG.1dcdb7941d17323998a0ac@news.nabs.net...
| Quote: | T Shadow (knone@zilch.com.invalid) wrote in alt.tv.tech.hdtv:
Ok, been doing some testing. Evidently the 18% was from when I had a
AIW128Pro in the computer and was still doing SVCD. Since then I've
installed an AIW9600XT as well as the HDTV Wonder and have been
recording
DVD High with the ATI MPG2 codec. I've put off doing this test to decide
between Half DVD(352X480,8mb/s) and burning to DVD High(720X480,8mb/s)
since I wouldn't be doing the editing till cold weather anyway. CPU
percentages are 30 and 55 respectively for both cards. No dropped
frames.
I can see a small difference in PQ between the two resolutions but not
near
enough for me to be willing to use twice the space. For me it's going to
be
Half DVD, when capturing analog, from now on.
That tells me the quality is pretty bad to begin with. Try capturing the
output of your DVD player using S-Video and see if "half" and "high" are
still close in quality. If they are, then I can pretty much say they both
suck without seeing either one.
I've never seen any other
reference to modern CPUs not being able to do DVD High.
Not all of us use "modern CPUs" in our DVRs. I have one machine with an
800MHz Pentium III, and used to use a 450MHz Pentium II.
I've never seen a setting for color depth in the codec.
Since you are using a DVD-compliant MPEG-2 codec, you won't get a choice.
On other codecs, you sometimes do, and reducing depth can save a lot of
CPU (and disc space).
--
Jeff Rife |
Ok. You know nothing about analog capture, CPU usage or digital ripping. |
Thanks for wasting my time. |
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Jeff Rife
Guest
|
| Posted:
Sun Oct 30, 2005 12:04 pm Post subject:
Re: Would I still be able to watch/record non-HDTV shows wit |
|
|
T Shadow (knone@zilch.com.invalid) wrote in alt.tv.tech.hdtv:
| Quote: | Ok. You know nothing about analog capture, CPU usage or digital ripping.
Thanks for wasting my time.
|
Well, sure, no problem.
Just go on thinking that your way is the only way (despite the fact
that there are at least three other posters in this thread who do things
differently from you).
Like other posters here, I don't believe in using the CPU to do something
which can be done better with a very small cost in hardware. $125 for
the hardware capture board is nothing when I can save $400 because I don't
have to buy a new motherboard or CPU.
And, I'm not sure where "digital ripping" comes in, other than the fact
that I suggested you use a very high quality source (DVD) as a test for
your analog capture methods when DVD is typically "ripped" instead.
If an analog capture of the test patterns from "Video Essentials" doesn't
look identical to the source, you don't even have the start of decent
quality captures, since the test patterns are fairly non-demanding as far
as compression loss goes, but do a good job testing the analog board
components.
--
Jeff Rife |
| http://www.nabs.net/Cartoons/OverTheHedge/Macarena.gif |
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T Shadow
Guest
|
| Posted:
Mon Oct 31, 2005 10:15 pm Post subject:
Re: Would I still be able to watch/record non-HDTV shows wit |
|
|
"Jeff Rife" <wevsr@nabs.net> wrote in message
news:MPG.1dce2c7bdb0375fa98a0ad@news.nabs.net...
| Quote: | T Shadow (knone@zilch.com.invalid) wrote in alt.tv.tech.hdtv:
Ok. You know nothing about analog capture, CPU usage or digital ripping.
Thanks for wasting my time.
Well, sure, no problem.
Just go on thinking that your way is the only way (despite the fact
that there are at least three other posters in this thread who do things
differently from you).
Like other posters here, I don't believe in using the CPU to do something
which can be done better with a very small cost in hardware. $125 for
the hardware capture board is nothing when I can save $400 because I don't
have to buy a new motherboard or CPU.
And, I'm not sure where "digital ripping" comes in, other than the fact
that I suggested you use a very high quality source (DVD) as a test for
your analog capture methods when DVD is typically "ripped" instead.
If an analog capture of the test patterns from "Video Essentials" doesn't
look identical to the source, you don't even have the start of decent
quality captures, since the test patterns are fairly non-demanding as far
as compression loss goes, but do a good job testing the analog board
components.
--
Jeff Rife |
Remember these posts. |
| Quote: | Some (but not all) PCI cards can only tune digital channels, and some can
tune both analog and digital but can only record digital channels. But,
even the ones that can record all channels (like the MyHD card I use) don't
do a very good job on the analog channels because they don't have any
compression hardware to assist with the recording.
Basically, unless a card has hardware encoding support (and I don't believe
the HDTV Wonder does), you sacrifice something even if you have a very,
very fast CPU.
|
A CPU can capture analog every bit as well as using hardware compression. If
the hardware was capturing something the CPU wasn't the file would be
bigger. Analog TV is not as high a quality as a DVD so capturing DVD proves
nothing about analog capture.
It's not just my opinion. Go to digitalfaq.com and see for yourself.
If you want to buy something that uses hardware compression instead of
getting a better CPU fine but stop this elitist BS about it's capture being
better. The analog source is the limiting factor not the capture device. If
I'm wrong about this give me a link. I won't reply again unless you provide
a link.
As far as ripping goes, why would you want to capture something you could
have an exact copy of? |
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Grant Edwards
Guest
|
| Posted:
Mon Oct 31, 2005 10:45 pm Post subject:
Re: Would I still be able to watch/record non-HDTV shows wit |
|
|
On 2005-10-28, Jeff Rife <wevsr@nabs.net> wrote:
| Quote: | I was reading
http://www.hot-deals.org/hdtv/2/#How.Does.HDTV.Compare.to.DVD
and read the section that said "If you have a HDTV PCI Card
for a PC, you will only be able to record HDTV channels."
Some (but not all) PCI cards can only tune digital channels,
and some can tune both analog and digital but can only record
digital channels.
|
I'm a bit baffled how a card could tune both channels but not
be able to record analog. The cards I'm familiar with don't
actually "record" anything. They just provide a video stream to
the application program. The application can choose to display
that stream, or it can write it to disk and "record" it. How
does a card prevent the application from writing the video
stream from the analog tuner to disk?
--
Grant Edwards grante Yow! DIDI... is that a
at MARTIAN name, or, are we
visi.com in ISRAEL? |
|
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Jeff Rife
Guest
|
| Posted:
Tue Nov 01, 2005 12:02 am Post subject:
Re: Would I still be able to watch/record non-HDTV shows wit |
|
|
T Shadow (knone@zilch.com.invalid) wrote in alt.tv.tech.hdtv:
| Quote: | A CPU can capture analog every bit as well as using hardware compression.
|
Yes, it *can*, but *does* it? Does the codec toss away things that the
hardware does not? There are many fights over which is the best MPEG-2
encoder, so it's pretty obvious that even the "same" compression can yield
wildly different results.
| Quote: | If
the hardware was capturing something the CPU wasn't the file would be
bigger.
|
That's absolutely not true. You don't need larger files to get better
perceived quality.
| Quote: | Analog TV is not as high a quality as a DVD so capturing DVD proves
nothing about analog capture.
|
"Proves nothing"...you just go on believing that, and the rest of us will
live in the real world. Maybe some more reading will teach what the
difference between a sources like DVD, laserdisc, and analog TV can show
you about your capture system, and why capturing straight to MPEG-2 in
software might not be the best thing to do.
| Quote: | It's not just my opinion. Go to digitalfaq.com and see for yourself.
|
Apparently, you should do some more reading over there.
| Quote: | If you want to buy something that uses hardware compression instead of
getting a better CPU fine but stop this elitist BS about it's capture being
better. The analog source is the limiting factor not the capture device. If
I'm wrong about this give me a link. I won't reply again unless you provide
a link.
|
Since you like the site so much, try
http://digitalfaq.com/dvdguides/capture/atimpeg/atimpeg.htm for a
start. Look at the many, many mistakes that can be made with software
capture without such a guide. Then, look at
http://digitalfaq.com/dvdguides/capture/intro.htm and see the part about
CPU limitations. When you start realizing that the CPU *is* the hardware
in this case, and realize that it is a *very* limiting factor (not fast
enough means you'd have to either drop frames or use a very low
resolution), you might realize how stupid you look.
| Quote: | As far as ripping goes, why would you want to capture something you could
have an exact copy of?
|
Because I actually *test* the quality of my capture hardware and software
instead of just guessing about it.
--
Jeff Rife | "I feel an intense ambivalence, some of which
| doesn't border entirely on the negative."
|
| -- Ned Dorsey, "Ned and Stacey" |
|
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Jeff Rife
Guest
|
| Posted:
Tue Nov 01, 2005 12:24 am Post subject:
Re: Would I still be able to watch/record non-HDTV shows wit |
|
|
Grant Edwards (grante@visi.com) wrote in alt.tv.tech.hdtv:
| Quote: | Some (but not all) PCI cards can only tune digital channels,
and some can tune both analog and digital but can only record
digital channels.
I'm a bit baffled how a card could tune both channels but not
be able to record analog.
|
Some don't provide any UI to record analog at all, because they didn't
want to be bothered with it, and they don't have open drivers, so you're
hosed.
Some don't provide DirectShow hooks for analog channels that allows a codec
to be applied...they will only write to an output surface (like a video
window). Sometimes, you can get around this with other software and
an advanced knowledge of DirectShow filters, but sometimes you can't.
| Quote: | How
does a card prevent the application from writing the video
stream from the analog tuner to disk?
|
There is no "analog stream". The tuner must do an A/D conversion of the
signal, but it doesn't have to hand that off to anything but the video
window. In handing it off, the video gets re-scaled and munged in other
ways, so you don't want to grab that for recording (even if you could).
You want the raw fram that was created from A/D conversion, and sometimes
you just can't get to that.
--
Jeff Rife | "Wheel of morality,
| Turn, turn, turn.
| Tell us the lesson
| That we should learn"
| -- Yakko, "Animaniacs" |
|
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|
|
Grant Edwards
Guest
|
| Posted:
Tue Nov 01, 2005 1:50 am Post subject:
Re: Would I still be able to watch/record non-HDTV shows wit |
|
|
On 2005-10-31, Jeff Rife <wevsr@nabs.net> wrote:
| Quote: | Some (but not all) PCI cards can only tune digital channels,
and some can tune both analog and digital but can only record
digital channels.
I'm a bit baffled how a card could tune both channels but not
be able to record analog.
Some don't provide any UI to record analog at all, because
they didn't want to be bothered with it, and they don't have
open drivers, so you're hosed.
|
So it's the drivers rather than the board that limits things.
| Quote: | Some don't provide DirectShow hooks for analog channels that
allows a codec to be applied...they will only write to an
output surface (like a video window). Sometimes, you can get
around this with other software and an advanced knowledge of
DirectShow filters, but sometimes you can't.
|
I don't speak Windows, but again that's a driver issue, and
nothing in the board itself right?
| Quote: | How does a card prevent the application from writing the video
stream from the analog tuner to disk?
There is no "analog stream". The tuner must do an A/D conversion of the
signal, but it doesn't have to hand that off to anything but the video
window.
|
What's a "video window"? Is it another chipset on the tuner
board that overlays a video window onto the VGA signals coming
out of a video board?
| Quote: | In handing it off, the video gets re-scaled and munged in
other ways, so you don't want to grab that for recording (even
if you could). You want the raw fram that was created from A/D
conversion, and sometimes you just can't get to that.
|
So you're saying the tuner card is also a video card and the
video data from the NTSC tuner and frame-grabber stays on-board?
--
Grant Edwards grante Yow! The LOGARITHM of
at an ISOCELES TRIANGLE is
visi.com TUESDAY WELD!! |
|
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|
|
Jeff Rife
Guest
|
| Posted:
Tue Nov 01, 2005 3:48 am Post subject:
Re: Would I still be able to watch/record non-HDTV shows wit |
|
|
Grant Edwards (grante@visi.com) wrote in alt.tv.tech.hdtv:
| Quote: | Some don't provide any UI to record analog at all, because
they didn't want to be bothered with it, and they don't have
open drivers, so you're hosed.
So it's the drivers rather than the board that limits things.
|
*Everything* concerning capture cards is a driver issue. :)
| Quote: | What's a "video window"?
|
The overlay onto the screen that displays the video. Windows has special
functions for this (and video cards support it with hardware) so that the
video gets placed onto the bitmap after everything else.
| Quote: | In handing it off, the video gets re-scaled and munged in
other ways, so you don't want to grab that for recording (even
if you could). You want the raw fram that was created from A/D
conversion, and sometimes you just can't get to that.
So you're saying the tuner card is also a video card and the
video data from the NTSC tuner and frame-grabber stays on-board?
|
No, that's not it. What happens is that the video gets passed across the
PCI bus to the video card which then places it on the output where it
belongs. This bypasses a lot of hooks (and munges the video to fit the
output format and window size), and sometimes the capture card does some
of the munging, so it's not really the raw frame.
Microsoft's DirectShow filter system is actually quite well thought out,
and any board that uses it to pass the captured data to other programs
won't have these issues, but some card that are primarily for HDTV just
chose not to do it. In particular, since MS MCE treated an ATSC/NTSC tuner
as exclusive or (you can either install a driver for the ATSC tuner or
the NTSC tuner), and people could buy NTSC capture cards for a lot less
than ATSC cards, some manufacturers just didn't support the NTSC part very
well.
Yes, in a sense it's all software issues, but that doesn't make it any
easier to work around.
--
Jeff Rife | "Don't try this at home, kids. This should
| be done only by trained professional idiots."
|
| -- Plucky Duck, "Hollywood Plucky" |
|
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