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Sci.Electronics.Basics -> Questions about equivalents of audio/video and digital/analog.
There are 304 messages in this thread.
You are currently looking at messages 140 to 160.
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Author: glen herrmannsfeldtDate: 22:15 20-08-07
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Radium wrote:
(snip)
> Real-time pitch-shifting is done for audio on the phone. Certain voice-
> changing devices allow women to sound like men on the phone, without
> decreasing the speed at which they talk. The pitch of the audio is
> decreased but the speed remains the same.
> I would like something similar to be done with the spatial and
> temporal of a video signal in real-time. I would like to be able to
> work not only for recorded video but also for video signals that are
> being transmitted/received in real-time -- such as a live TV show.
Normally this is done by removing the appropriate frames (samples),
or duplicating them. One example is the 3-2 pulldown used to convert
24 frame/second movies to 59.94 field/second video.
>>I ~think~ I get what Radium wants - he wants to be able to modify a
>>recorded scene the way one can modify a CGI virtual scene, e.g. by
>>setting a slower wing flapping rate while leaving other parts of the
>>scene unchanged.
> Actually I don't want other parts to be unchanged. What I would like
> is the temporal frequencies [of all parts of the video] to be
> decreased but without decreasing the speed of the video signal.
That might be harder. For audio, it can be chopped, such as
removing 1/60th of a second every 1/20th to speed it up by 1.5.
If that is done faster than the modulation (vocalization),
and slower than the frequencies of interest (maybe 400Hz-3.5kHz
for voice) it works pretty well. Probably less well for music.
As far as I know, that is usually done asynchronously to the
source signal. One could imagine removing cycles of a 1.23kHz
voice, for example.
For video the modulation (wing flapping) is not separate from
the source frequency. If you know you are trying to separate
wing flapping, it could be done by cutting out whole flap
cycles, assuming only one bird is in the scene, and is doing
most of the motion. Otherwise, I don't think there is anything
you could do.
-- glen
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Author: glen herrmannsfeldtDate: 22:27 20-08-07
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Floyd L. Davidson wrote:
(snip)
> Actually I suspect it is open to debate as to whether a
> sample is actually PAM until it is quantized. (Until it
> is, it's just a sample of an analog signal.) But
> whatever, if the sample itself actually is PAM, then yes
> that is an analog signal.
Phase modulation can be done continuously, and so can
amplitude modulation. The NTSC chroma subcarrier is
pretty much PAM, where the phase indicates the hue and
amplitude the intensity of the color.
NTSC isn't actually described that way due to the desire to get
just a little more resolution out of the signal. The eye is
more sensitive to spatial resolution between some colors than
others (and not along the obvious R-G-B axes), and NTSC encodes
that. Only very recently were TV receivers built to decode that
extra information, at about the same time ATSC tuners are taking
over.
-- glen
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Author: RadiumDate: 22:37 20-08-07
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On Aug 20, 7:05 pm, "Ron N." <rhnlo...@yahoo.com> wrote:
> On Aug 20, 6:40 pm, Radium <gluceg...@gmail.com> wrote:
> > I want all temporal components of the video signal to be slowed
> > without changing the length or speed of the video. Just like Adobe
> > Audition and certain voice-changers allow the pitch of the audio
> > signal to be decreased without changing the length or speed of the
> > audio.
> But pitch changing software does change the speed of
> all the details in the audio. Instead of 200 vibrations
> per phoneme, you might get only 100 after the pitch
> changer does its distortion. The onset of the phoneme
> will be 5 mS less accurate.
I am fine with that.
> I suppose the equivalent
> in the temporal component of a video scan line would
> be taking a picture of a house with 6 or 8 windows and
> changing the house to be about the same width but only
> having 3 or 4 windows across, and maybe moving the house
> so that it is an even number of window widths from the
> house next door. An artist could probably do this kind
> kind of caricature for you before storing a lower
> data rate description of the resulting picture.
I still think a more precise example of an equivalent is the wing-
flapping I described.
In the video signal containing the flapping-wings, all temporal
components of the video [including the flap-rate] are slowed without
increasing the length of the video. The video clip remains just as
short.
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Author: Floyd L. DavidsonDate: 23:14 20-08-07
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Don Bowey <dbowey@comcast.net> wrote:
>On 8/20/07 5:43 PM, in article 876439hg3o.fld@apaflo.com, "Floyd L.
>Davidson" <floyd@apaflo.com> wrote:
>
>> nospam@nospam.com (Don Pearce) wrote:
>>> On 20 Aug 2007 21:42:18 GMT, Scott Seidman
>>> <namdiesttocs@mindspring.com> wrote:
>>>
>>>> floyd@apaflo.com (Floyd L. Davidson) wrote in
>>>> news:87zm0mjrfy.fld@apaflo.com:
>>>>
>>>>>> quantized - a sampled signal, but with the possible levels
constrained
>>>>>> to a limited set of values
>>>>>
>>>>> That is by definition a digital siganl. As soon as the possible
values
>>>>> are "constrained to a limited set", it is by definition
digital data.
>>>>>
>>>>>
>>>>
>>>> Wouldn't this make the output of a D/A converter digital by definition?
>>>
>>> It certainly would. But apparently there are those that can't see the
>>> difference between a limited set of values, and a set of numbers
>>> describing those values.
>>
>> You don't appear to understand that the limited set of values makes
>> it digital, by definition. PERIOD.
>>
>> Of course if you then run that digital PAM signal through virtually
>> any analog channel, it no longer has a limited set of values...
>
>Including a two foot piece of cable, or two inches with a small cap.
Nope. It would take a fair sized cap.
Keep in mind that that is *exactly* what a V.90 modem puts on a
regular twisted pair telephone cable, and it works just fine for
a couple miles at least, sometimes even much farther.
And that signal is digital, and is processed as a digital signal
by the receiving modem.
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>;
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
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Author: Floyd L. DavidsonDate: 23:17 20-08-07
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glen herrmannsfeldt <gah@ugcs.caltech.edu> wrote:
>Floyd L. Davidson wrote:
>
>(snip)
>
>> Analog signals are by *definition* continous.
>
>> You have misunderstood what that means though. The
>> analog value of a signal is continuous, but that does
>> not imply that the signal continuously exists or that
>> it even changes at all.
>
>There needs to be a way to describe sampled but not quantized
>signals. They are not continuous in time, but the function
>can take on any value at each sample point.
Exactly.
>It does occur to me that you could have quantized but not
>sampled data. It works best gray coded so that there isn't
>a problem at transitions. This is sometimes done for rotational
>encoders, where the rotation angle can be continuous such
>that transitions can occur at any time.
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>;
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
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Author: glen herrmannsfeldtDate: 23:44 20-08-07
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Floyd L. Davidson wrote:
(snip)
> Analog signals are by *definition* continous.
> You have misunderstood what that means though. The
> analog value of a signal is continuous, but that does
> not imply that the signal continuously exists or that
> it even changes at all.
There needs to be a way to describe sampled but not quantized
signals. They are not continuous in time, but the function
can take on any value at each sample point.
It does occur to me that you could have quantized but not
sampled data. It works best gray coded so that there isn't
a problem at transitions. This is sometimes done for rotational
encoders, where the rotation angle can be continuous such
that transitions can occur at any time.
-- glen
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Author: iswDate: 00:01 21-08-07
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In article <XKWdneKkG60xSVXbnZ2dnUVZ_gednZ2d@rcn.net>,
Jerry Avins <jya@ieee.org> wrote:
> Radium wrote:
> > Hi:
> >
> > I. Audio vs. Video
> >
> > Digitized (mono) audio has a single sample per each sampling
> > interval.
>
> Yes. several bits per sample, many samples per second.
>
> > In the case of digital video, we could treat each individual sample
> > point location in the sampling grid (each pixel position in a frame)
> > the same way as if it was a sample from an individual (mono) audio
> > signal that continues on the same position in the next frame. For
> > example, a 640?480 pixel video stream shot at 30 fps would be treated
> > mathematically as if it consisted of 307200 parallel, individual mono
> > audio streams [channels] at a 30 Hz sample rate. Where does bit-
> > resolution enter the equation?
>
> It might actually make sense to look at it that way in some situations,
> but I'll bet you can't think of one.
How about a T1 (DS1) stream? It's a series of 8-bit audio samples, with
frame sync.
Isaac
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Author: Don BoweyDate: 00:02 21-08-07
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On 8/20/07 8:14 PM, in article 874pitfujh.fld@apaflo.com, "Floyd L.
Davidson" <floyd@apaflo.com> wrote:
> Don Bowey <dbowey@comcast.net> wrote:
>> On 8/20/07 5:43 PM, in article 876439hg3o.fld@apaflo.com, "Floyd L.
>> Davidson" <floyd@apaflo.com> wrote:
>>
>>> nospam@nospam.com (Don Pearce) wrote:
>>>> On 20 Aug 2007 21:42:18 GMT, Scott Seidman
>>>> <namdiesttocs@mindspring.com> wrote:
>>>>
>>>>> floyd@apaflo.com (Floyd L. Davidson) wrote in
>>>>> news:87zm0mjrfy.fld@apaflo.com:
>>>>>
>>>>>>> quantized - a sampled signal, but with the possible levels
constrained
>>>>>>> to a limited set of values
>>>>>>
>>>>>> That is by definition a digital siganl. As soon as the
possible values
>>>>>> are "constrained to a limited set", it is by
definition digital data.
>>>>>>
>>>>>>
>>>>>
>>>>> Wouldn't this make the output of a D/A converter digital by
definition?
>>>>
>>>> It certainly would. But apparently there are those that can't see the
>>>> difference between a limited set of values, and a set of numbers
>>>> describing those values.
>>>
>>> You don't appear to understand that the limited set of values makes
>>> it digital, by definition. PERIOD.
>>>
>>> Of course if you then run that digital PAM signal through virtually
>>> any analog channel, it no longer has a limited set of values...
>>
>> Including a two foot piece of cable, or two inches with a small cap.
>
> Nope. It would take a fair sized cap.
>
> Keep in mind that that is *exactly* what a V.90 modem puts on a
> regular twisted pair telephone cable, and it works just fine for
> a couple miles at least, sometimes even much farther.
>
> And that signal is digital, and is processed as a digital signal
> by the receiving modem.
Digital data CSUs and T1 transmitter line signals are digital and look
similar to distorted square waves. An all 1's signal looks like a distorted
sinewave .
Using the same V.90 example....... It will work as well if two v.90 modems
are connected back-to-back by a short pair of wires.
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Author: Jerry AvinsDate: 00:20 21-08-07
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Floyd L. Davidson wrote:
> Jerry Avins <jya@ieee.org> wrote:
>> Floyd L. Davidson wrote:
>>> Jerry Avins <jya@ieee.org> wrote:
>> ...
>>
>>>> I can
>>>> demonstrate a circuit using analog components that
>>>> transforms a continuous ramp input into a staircase
>>>> output. Moreover, the output levels can be individually
>>>> adjusted. Is the output digital? (We're discussing an
>>>> arbitrary definition here. There is no wrong answer.)
>>> The output is apparenlty analog. At least you have
>>> said
>>> *nothing* that indicates otherwise.
>> Apparently analog but actually digital? That would be in
>> keeping with your assertion that quantizing an otherwise
>> analog signal digitizes it.
>
> You *didn't* quantize it. Or at least nothing you said
> assures that it has been quantized, and given "levels can
> be individually adjusted" is high suggests that it is not
> quantized.
>
>>> Do you think all digital signals are square waves and
>>> anything that has square waves is digital? Your example
>>> above suggests that you might, but it simply isn't true.
>> By old vacuum-tube signal generator was certainly
>> analog. It produced square waves among other wave shapes.
>
> Hot damned, you *are* aware of that. Amazing...
You know, Floyd, legal definitions don't always reflect reality. Back in
the 50s, the speed limit on Storrow drive in Boston was 35 mph. By law,
exceeding 50 mph in a 35 mph zone was statutory reckless driving. To
expedite traffic, the police let it be known publicly that they wouldn't
give speeding tickets during rush-hour, leaving motorists free to travel
up to 50 mph without consequence. One night about 1:00 AM I got a ticket
for reckless driving by going 55 mph on an empty road. I pleaded not
guilty and offered to plead guilty to speeding. I argued that if 50 mph
was perfectly OK on a crowded road, 55 mph wasn't reckless no matter how
the law read. I remember the judges words: "You're a little snotnose.
I'd love to fine you for speeding, but you're not charged with that.
Case dismissed!"
I'm still a little snotnose, and partitioning a signal into approximate
levels -- because of noise the levels can never be exact -- doesn't make
it digital *in fact*, whatever the gummint might declare.
Jerry
--
Engineering is the art of making what you want from things you can get.
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
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Author: Ron N.Date: 00:21 21-08-07
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On Aug 20, 6:40 pm, Radium <gluceg...@gmail.com> wrote:
> On Aug 20, 7:15 pm, glen herrmannsfeldt <g...@ugcs.caltech.edu> wrote:
>
> > For video the modulation (wing flapping) is not separate from
> > the source frequency. If you know you are trying to separate
> > wing flapping, it could be done by cutting out whole flap
> > cycles, assuming only one bird is in the scene, and is doing
> > most of the motion. Otherwise, I don't think there is anything
> > you could do.
>
> I don't want to separate the wing-flapping or anything from the video.
> I want all temporal components of the video signal to be slowed
> without changing the length or speed of the video. Just like Adobe
> Audition and certain voice-changers allow the pitch of the audio
> signal to be decreased without changing the length or speed of the
> audio.
Pitch shifters remove (or duplicate) cycles. For instance,
if you have a video of a car driving past a house with six
windows in one second, and you slow the video down to half
speed it will normally take two seconds to show the complete
video. However, if you just chop out of the video portions
showing the car between, say, the odd numbered windows of the
house, then you can show the jerky left over video in only
one second. If you chopped out the odd numbered windows
from the pictures of the house, and stretched out the portions
with the even numbered windows, then it might look like a
car twice as long was driving in front of a house with less
windows, or it might look like something Dali or Picasso
would draw during a hangover.
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Author: Jerry AvinsDate: 00:22 21-08-07
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Floyd L. Davidson wrote:
> Jerry Avins <jya@ieee.org> wrote:
>> Floyd L. Davidson wrote:
>>> Jerry Avins <jya@ieee.org> wrote:
>>>> ... A signal can be
>>>> quantized without any need to measure it or describe it
>>>> with a number.
>>> That isn't true. In order to quantize it you *must*
>>> decide on non-overlapping ranges of *values*, and a
>>> specific quantity value that equates to those values.
>>>
>>>> An example is the signal being measured
>>>> in a quantum Hall-effect experiment.
>>> Explain.
>> http://www.warwick.ac.uk/~phsbm/qhe.htm
>
> Why don't you tell us what you think this means. I
> have no need to spend my time tracking down your
> comments.
Live and learn, or live and don't learn. Your choice. I'm indifferent.
Jerry
--
Engineering is the art of making what you want from things you can get.
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
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Author: Jerry AvinsDate: 00:29 21-08-07
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Floyd L. Davidson wrote:
> Don Bowey <dbowey@comcast.net> wrote:
>> On 8/20/07 5:43 PM, in article 876439hg3o.fld@apaflo.com, "Floyd L.
>> Davidson" <floyd@apaflo.com> wrote:
>>
>>> nospam@nospam.com (Don Pearce) wrote:
>>>> On 20 Aug 2007 21:42:18 GMT, Scott Seidman
>>>> <namdiesttocs@mindspring.com> wrote:
>>>>
>>>>> floyd@apaflo.com (Floyd L. Davidson) wrote in
>>>>> news:87zm0mjrfy.fld@apaflo.com:
>>>>>
>>>>>>> quantized - a sampled signal, but with the possible levels
constrained
>>>>>>> to a limited set of values
>>>>>> That is by definition a digital siganl. As soon as the
possible values
>>>>>> are "constrained to a limited set", it is by
definition digital data.
>>>>>>
>>>>>>
>>>>> Wouldn't this make the output of a D/A converter digital by
definition?
>>>> It certainly would. But apparently there are those that can't see the
>>>> difference between a limited set of values, and a set of numbers
>>>> describing those values.
>>> You don't appear to understand that the limited set of values makes
>>> it digital, by definition. PERIOD.
>>>
>>> Of course if you then run that digital PAM signal through virtually
>>> any analog channel, it no longer has a limited set of values...
>> Including a two foot piece of cable, or two inches with a small cap.
>
> Nope. It would take a fair sized cap.
>
> Keep in mind that that is *exactly* what a V.90 modem puts on a
> regular twisted pair telephone cable, and it works just fine for
> a couple miles at least, sometimes even much farther.
>
> And that signal is digital, and is processed as a digital signal
> by the receiving modem.
The signal is amplified in analog repeaters and again in the modem. Your
categories are too hard edged. The very purpose of a modem is converting
digital signal to analog that can traverse an analog phone line and back
again to digital at the far end. A modem might be the worst example of a
purely digital I can imagine.
Jerry
--
Engineering is the art of making what you want from things you can get.
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
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Author: Jerry AvinsDate: 00:32 21-08-07
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isw wrote:
> In article <XKWdneKkG60xSVXbnZ2dnUVZ_gednZ2d@rcn.net>,
> Jerry Avins <jya@ieee.org> wrote:
>
>> Radium wrote:
>>> Hi:
>>>
>>> I. Audio vs. Video
>>>
>>> Digitized (mono) audio has a single sample per each sampling
>>> interval.
>> Yes. several bits per sample, many samples per second.
>>
>>> In the case of digital video, we could treat each individual sample
>>> point location in the sampling grid (each pixel position in a frame)
>>> the same way as if it was a sample from an individual (mono) audio
>>> signal that continues on the same position in the next frame. For
>>> example, a 640?480 pixel video stream shot at 30 fps would be treated
>>> mathematically as if it consisted of 307200 parallel, individual mono
>>> audio streams [channels] at a 30 Hz sample rate. Where does bit-
>>> resolution enter the equation?
>> It might actually make sense to look at it that way in some situations,
>> but I'll bet you can't think of one.
>
> How about a T1 (DS1) stream? It's a series of 8-bit audio samples, with
> frame sync.
>
> Isaac
Are you Radium in disguise? My bet was with him.
Jerry
--
Engineering is the art of making what you want from things you can get.
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
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Author: Floyd L. DavidsonDate: 01:19 21-08-07
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Don Bowey <dbowey@comcast.net> wrote:
>On 8/20/07 8:14 PM, in article 874pitfujh.fld@apaflo.com, "Floyd L.
>Davidson" <floyd@apaflo.com> wrote:
>
>> Don Bowey <dbowey@comcast.net> wrote:
>>> On 8/20/07 5:43 PM, in article 876439hg3o.fld@apaflo.com, "Floyd L.
>>> Davidson" <floyd@apaflo.com> wrote:
>>>
>>>> nospam@nospam.com (Don Pearce) wrote:
>>>>> On 20 Aug 2007 21:42:18 GMT, Scott Seidman
>>>>> <namdiesttocs@mindspring.com> wrote:
>>>>>
>>>>>> floyd@apaflo.com (Floyd L. Davidson) wrote in
>>>>>> news:87zm0mjrfy.fld@apaflo.com:
>>>>>>
>>>>>>>> quantized - a sampled signal, but with the possible
levels constrained
>>>>>>>> to a limited set of values
>>>>>>>
>>>>>>> That is by definition a digital siganl. As soon as the
possible values
>>>>>>> are "constrained to a limited set", it is by
definition digital data.
>>>>>>>
>>>>>>>
>>>>>>
>>>>>> Wouldn't this make the output of a D/A converter digital by
definition?
>>>>>
>>>>> It certainly would. But apparently there are those that can't see
the
>>>>> difference between a limited set of values, and a set of numbers
>>>>> describing those values.
>>>>
>>>> You don't appear to understand that the limited set of values makes
>>>> it digital, by definition. PERIOD.
>>>>
>>>> Of course if you then run that digital PAM signal through virtually
>>>> any analog channel, it no longer has a limited set of values...
>>>
>>> Including a two foot piece of cable, or two inches with a small cap.
>>
>> Nope. It would take a fair sized cap.
>>
>> Keep in mind that that is *exactly* what a V.90 modem puts on a
>> regular twisted pair telephone cable, and it works just fine for
>> a couple miles at least, sometimes even much farther.
>>
>> And that signal is digital, and is processed as a digital signal
>> by the receiving modem.
>
>Digital data CSUs and T1 transmitter line signals are digital and look
>similar to distorted square waves. An all 1's signal looks like a distorted
>sinewave .
Your point is? (Besides the poor description? They
don't look like distorted square waves. The look like
only slightly distorted sine waves!)
>Using the same V.90 example....... It will work as well if two v.90 modems
>are connected back-to-back by a short pair of wires.
It won't. They can't talk to each other that way except
using v.34 protocols.
Regardless, what is your point? I said that v.90 works
fine for a couple of *miles*, minimum, so what
significance would there be to working "back-to-back by
a short pair of wires"?
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>;
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
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Author: Floyd L. DavidsonDate: 01:24 21-08-07
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Jerry Avins <jya@ieee.org> wrote:
>Floyd L. Davidson wrote:
>> Jerry Avins <jya@ieee.org> wrote:
>>> Floyd L. Davidson wrote:
>>>> Jerry Avins <jya@ieee.org> wrote:
>>> ...
>>>
>>>>> I can
>>>>> demonstrate a circuit using analog components that
>>>>> transforms a continuous ramp input into a staircase
>>>>> output. Moreover, the output levels can be individually
>>>>> adjusted. Is the output digital? (We're discussing an
>>>>> arbitrary definition here. There is no wrong answer.)
>>>> The output is apparenlty analog. At least you have
>>>> said
>>>> *nothing* that indicates otherwise.
>>> Apparently analog but actually digital? That would be in
>>> keeping with your assertion that quantizing an otherwise
>>> analog signal digitizes it.
>> You *didn't* quantize it. Or at least nothing you said
>> assures that it has been quantized, and given "levels can
>> be individually adjusted" is high suggests that it is not
>> quantized.
>>
>>>> Do you think all digital signals are square waves and
>>>> anything that has square waves is digital? Your example
>>>> above suggests that you might, but it simply isn't true.
>>> By old vacuum-tube signal generator was certainly
>>> analog. It produced square waves among other wave shapes.
>> Hot damned, you *are* aware of that. Amazing...
>
>You know, Floyd, legal definitions don't always reflect
>reality.
You know Jerry, *technical* definitions are reality.
You can fight it all you like, but it won't change the
fact that to talk to anyone about this topic *requires* that
we all use the same definitions, and the ones that I've
cited *are* the standard definitions used by *everyone*
that is credible.
...
>law read. I remember the judges words: "You're a little
>snotnose. I'd love to fine you for speeding, but you're
>not charged with that. Case dismissed!"
>
>I'm still a little snotnose, and partitioning a signal
>into approximate levels -- because of noise the levels
>can never be exact -- doesn't make it digital *in fact*,
>whatever the gummint might declare.
You aren't a little snotnose. Your just a little
foolish, that's all. Everyone is about something, and
that's where you've chosen to make your stand.
Regardless of how silly you want to be, it *does* make
it digital, by definition.
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>;
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
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Author: Floyd L. DavidsonDate: 01:25 21-08-07
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Jerry Avins <jya@ieee.org> wrote:
>Floyd L. Davidson wrote:
>> Jerry Avins <jya@ieee.org> wrote:
>>> Floyd L. Davidson wrote:
>>>> Jerry Avins <jya@ieee.org> wrote:
>>>>> ... A signal can be
>>>>> quantized without any need to measure it or describe it
>>>>> with a number.
>>>> That isn't true. In order to quantize it you *must*
>>>> decide on non-overlapping ranges of *values*, and a
>>>> specific quantity value that equates to those values.
>>>>
>>>>> An example is the signal being measured
>>>>> in a quantum Hall-effect experiment.
>>>> Explain.
>>> http://www.warwick.ac.uk/~phsbm/qhe.htm
>> Why don't you tell us what you think this means. I
>> have no need to spend my time tracking down your
>> comments.
>
>Live and learn, or live and don't learn. Your choice. I'm indifferent.
I noticed that you have no intention of learning anything.
My point was that I see *nothing* on that web page which
supports anything you've stated. If you do, be my guest
and make an even greater fool of yourself than you have
at this point.
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>;
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
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Author: Floyd L. DavidsonDate: 01:31 21-08-07
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Jerry Avins <jya@ieee.org> wrote:
>Floyd L. Davidson wrote:
>> Don Bowey <dbowey@comcast.net> wrote:
>>> On 8/20/07 5:43 PM, in article 876439hg3o.fld@apaflo.com, "Floyd L.
>>> Davidson" <floyd@apaflo.com> wrote:
>>>
>>>> nospam@nospam.com (Don Pearce) wrote:
>>>>> On 20 Aug 2007 21:42:18 GMT, Scott Seidman
>>>>> <namdiesttocs@mindspring.com> wrote:
>>>>>
>>>>>> floyd@apaflo.com (Floyd L. Davidson) wrote in
>>>>>> news:87zm0mjrfy.fld@apaflo.com:
>>>>>>
>>>>>>>> quantized - a sampled signal, but with the possible
levels constrained
>>>>>>>> to a limited set of values
>>>>>>> That is by definition a digital siganl. As soon as the
possible values
>>>>>>> are "constrained to a limited set", it is by
definition digital data.
>>>>>>>
>>>>>>>
>>>>>> Wouldn't this make the output of a D/A converter digital by
definition?
>>>>> It certainly would. But apparently there are those that can't see
the
>>>>> difference between a limited set of values, and a set of numbers
>>>>> describing those values.
>>>> You don't appear to understand that the limited set of values makes
>>>> it digital, by definition. PERIOD.
>>>>
>>>> Of course if you then run that digital PAM signal through virtually
>>>> any analog channel, it no longer has a limited set of values...
>>> Including a two foot piece of cable, or two inches with a small cap.
>> Nope. It would take a fair sized cap.
>> Keep in mind that that is *exactly* what a V.90 modem
>> puts on a
>> regular twisted pair telephone cable, and it works just fine for
>> a couple miles at least, sometimes even much farther.
>> And that signal is digital, and is processed as a
>> digital signal
>> by the receiving modem.
>
>The signal is amplified in analog repeaters and again in
>the modem.
There simply are no such things as "analog repeaters"
on local telephone loops.
Where do you get these funny ideas.
>Your categories are too hard edged.
There isn't any other way.
>The very
>purpose of a modem is converting digital signal to
>analog that can traverse an analog phone line and back
>again to digital at the far end. A modem might be the
>worst example of a purely digital I can imagine.
A "modem" can't be "purely digital", because it
necessarily has a digital side and an analog side. But
a v.90 modem is a bit different, because it is indeed a
modem for the *uplink*, which uses v.34 protocols. It
is *not* a modem for the downlink, but instead is a
digital encoder.
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>;
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
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Author: Don BoweyDate: 01:48 21-08-07
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On 8/20/07 10:19 PM, in article 87odh1ea6x.fld@apaflo.com, "Floyd L.
Davidson" <floyd@apaflo.com> wrote:
> Don Bowey <dbowey@comcast.net> wrote:
>> On 8/20/07 8:14 PM, in article 874pitfujh.fld@apaflo.com, "Floyd L.
>> Davidson" <floyd@apaflo.com> wrote:
>>
>>> Don Bowey <dbowey@comcast.net> wrote:
>>>> On 8/20/07 5:43 PM, in article 876439hg3o.fld@apaflo.com, "Floyd
L.
>>>> Davidson" <floyd@apaflo.com> wrote:
>>>>
>>>>> nospam@nospam.com (Don Pearce) wrote:
>>>>>> On 20 Aug 2007 21:42:18 GMT, Scott Seidman
>>>>>> <namdiesttocs@mindspring.com> wrote:
>>>>>>
>>>>>>> floyd@apaflo.com (Floyd L. Davidson) wrote in
>>>>>>> news:87zm0mjrfy.fld@apaflo.com:
>>>>>>>
>>>>>>>>> quantized - a sampled signal, but with the possible
levels constrained
>>>>>>>>> to a limited set of values
>>>>>>>>
>>>>>>>> That is by definition a digital siganl. As soon as the
possible values
>>>>>>>> are "constrained to a limited set", it is by
definition digital data.
>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>> Wouldn't this make the output of a D/A converter digital by
definition?
>>>>>>
>>>>>> It certainly would. But apparently there are those that can't
see the
>>>>>> difference between a limited set of values, and a set of
numbers
>>>>>> describing those values.
>>>>>
>>>>> You don't appear to understand that the limited set of values makes
>>>>> it digital, by definition. PERIOD.
>>>>>
>>>>> Of course if you then run that digital PAM signal through virtually
>>>>> any analog channel, it no longer has a limited set of values...
>>>>
>>>> Including a two foot piece of cable, or two inches with a small cap.
>>>
>>> Nope. It would take a fair sized cap.
>>>
>>> Keep in mind that that is *exactly* what a V.90 modem puts on a
>>> regular twisted pair telephone cable, and it works just fine for
>>> a couple miles at least, sometimes even much farther.
>>>
>>> And that signal is digital, and is processed as a digital signal
>>> by the receiving modem.
>>
>> Digital data CSUs and T1 transmitter line signals are digital and look
>> similar to distorted square waves. An all 1's signal looks like a distorted
>> sinewave .
>
> Your point is? (Besides the poor description? They
> don't look like distorted square waves. The look like
> only slightly distorted sine waves!)
Have you looked at a DSX-1 envelope lately?
>
>> Using the same V.90 example....... It will work as well if two v.90 modems
>> are connected back-to-back by a short pair of wires.
>
> It won't. They can't talk to each other that way except
> using v.34 protocols.
>
> Regardless, what is your point? I said that v.90 works
> fine for a couple of *miles*, minimum, so what
> significance would there be to working "back-to-back by
> a short pair of wires"?
My point is...... You are making too much of your point that "Of course if
you then run that digital PAM signal through virtually any analog channel,
it no longer has a limited set of values."
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Author: Ray FischerDate: 01:53 21-08-07
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Radium <glucegen1@gmail.com> wrote:
>On Aug 19, 2:50 pm, rfisc...@sonic.net (Ray Fischer) wrote:
>
>> Radium <gluceg...@gmail.com> wrote:
>
>> >Hi:
>
>> >I. Audio vs. Video
>
>> >Digitized (mono) audio has a single sample per each sampling
>> >interval.
>
>> >In the case of digital video, we could treat each individual sample
>> >point location in the sampling grid (each pixel position in a frame)
>> >the same way as if it was a sample from an individual (mono) audio
>> >signal that continues on the same position in the next frame. For
>> >example, a 640×480 pixel video stream shot at 30 fps would be treated
>> >mathematically as if it consisted of 307200 parallel, individual mono
>> >audio streams [channels] at a 30 Hz sample rate. Where does bit-
>> >resolution enter the equation?
>
>> >Digital linear PCM audio has the following components:
>
>> >1. Sample rate [44.1 KHz for CD audio]
>> >2. Channels [2 in stereo, 1 in monaural]
>> >3. Bit-resolution [16-bit for CD audio]
>
>> >Sample rate in audio = frame rate in video
>> >Channel in audio = pixel in video
>> >Bit-resolution in audio = ? in video
>
>> >Is it true that unlike the-frequency-of-audio, the-frequency-of-video
>> >has two components -- temporal and spatial?
>
>> No. Video is converted to a linear data stream corresponding
>> (roughly) to scan lines. The color and brightness information
>> is split apart and converted into parallel data streams.
>
>Okay. So a digital video device with greater bit-resolution can allow
>for more levels of luminance?
Yes.
>What is the video-equivalent of bit-resolution?
Analog or digital?
>> Compression for digital video may group areas of the image
>> and/or eliminate some of the color components.
>
>Does compression also eliminate some of the brightness components?
Not usually.
>> >II. Digital vs. Analog
>
>> >Sample-rate is a digital entity. In a digital audio device, the sample-
>> >rate must be at least 2x the highest intended frequency of the digital
>> >audio signal. What is the analog-equivalent of sample-rate?
>
>> There is no sampling in analog so there is no sampling rate.
>
>There is no analog-equivalent of sample-rate? Then what the limits the
>highest frequency an analog audio device can encode?
Usually the capacitance and inductance of the circuits.
>What determines the highest frequency signal an analog solid-state
>audio device can input without distortion?
>
>Analog solid-state audio device = a purely analog electronic device
>that can record, store, playback, and process audio signals without
>needing any moving parts.
No such thing.
>The above device inputs the electrical signals generated by an
>attached microphone. These electric signals are AC and represent the
>sound in "electronic" form. Sound with a higher-frequency will
>generate a faster-alternating current than sound with a lower-
>frequency. A louder sound will generate an alternating-current with a
>bigger peak-to-peak wattage than a softer soft.
>
>What mathematically determines the highest-frequency electric signal
>such a device can intake without distortion?
For that you need a degree in electrical engineering.
--
Ray Fischer
rfischer@sonic.net
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Author: Don BoweyDate: 01:58 21-08-07
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On 8/20/07 10:31 PM, in article 87bqd1e9n8.fld@apaflo.com, "Floyd L.
Davidson" <floyd@apaflo.com> wrote:
> There simply are no such things as "analog repeaters"
> on local telephone loops.
Since when?
If a loop is long enough, and there is no pair-gain facility available, it
gets an "E" type repeater. If that isn't an analog repeater nothing is.
>
> Where do you get these funny ideas.
(snip)
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Contact | Electronic Portal
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