Questions about equivalents of audio/video and digital/analog.

Discussion in 'Digital Photography' started by Radium, Aug 19, 2007.

  1. Radium

    Radium Guest

    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?

    AFAIK, the-frequency-of-audio only has a temporal component. Do I
    guess right?

    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? In an
    analog audio device, does this equivalent need to be at least 2x the
    highest intended frequency of the analog audio signal? If not, then
    what is the minimum frequency that the analog-equivalent-of-sample-
    rate must be in relation to the analog audio signal?

    III. My Requests:

    No offense but please respond with reasonable answers & keep out the
    jokes, off-topic nonsense, taunts, insults, and trivializations. I am
    really interested in this.


    Thanks for your assistance, cooperation, and understanding,

    Radium
    Radium, Aug 19, 2007
    #1
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  2. Radium

    Ray Fischer Guest

    Radium <> 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.

    Compression for digital video may group areas of the image
    and/or eliminate some of the color components.

    >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.

    --
    Ray Fischer
    Ray Fischer, Aug 19, 2007
    #2
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  3. Radium

    Ken Maltby Guest

    "Ray Fischer" <> wrote in message
    news:46c8bb30$0$14150$...
    > Radium <> 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.
    >
    > Compression for digital video may group areas of the image
    > and/or eliminate some of the color components.
    >
    >>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.
    >
    > --
    > Ray Fischer
    >
    >


    You might want to check into the posting history of
    "Radium".

    Luck;
    Ken
    Ken Maltby, Aug 20, 2007
    #3
  4. Radium

    Jerry Avins Guest

    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. As for bit resolution, what does
    that term mean to you? I think it means the number of bits used to
    represent each sample, whatever the situation.

    > Digital linear PCM audio has the following components:
    >
    > 1. Sample rate [44.1 KHz for CD audio]


    One particular kind of audio. Common uncompressed audio rates range from
    8 to 96 KHz.

    > 2. Channels [2 in stereo, 1 in monaural]


    Up to 5 in home theater systems.

    > 3. Bit-resolution [16-bit for CD audio]


    So you do know what the term means. Why did you ask then? Easier than
    thinking?

    > Sample rate in audio = frame rate in video


    Bullshit.

    > Channel in audio = pixel in video


    Bullshit.

    > Bit-resolution in audio = ? in video


    Bit resolution.

    > Is it true that unlike the-frequency-of-audio, the-frequency-of-video
    > has two components -- temporal and spatial?


    Good question. The signal has a frequency spectrum. A still image has a
    spatial spectrum. A video signal represents a series of still images.

    > AFAIK, the-frequency-of-audio only has a temporal component. Do I
    > guess right?


    Yes, until the sound gets into a room. then it has a spatial element
    too. Think reflections and standing waves.

    > 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? In an
    > analog audio device, does this equivalent need to be at least 2x the
    > highest intended frequency of the analog audio signal? If not, then
    > what is the minimum frequency that the analog-equivalent-of-sample-
    > rate must be in relation to the analog audio signal?


    There are no samples in an analog system, so there is no sample rate.

    > III. My Requests:
    >
    > No offense but please respond with reasonable answers & keep out the
    > jokes, off-topic nonsense, taunts, insults, and trivializations. I am
    > really interested in this.


    Look, guy: you could probably read by the time you were three years old.
    Bully for you! (Precocious reading is almost a /sine qua non/ of
    Asperger's.) I have news for you: growing up _doesn't_ mean that one
    stops reading. Get a good book or read some of the on-line material
    collected at http://www.dspguru.com/ and learn the basics of your
    interest. Above all, stop guessing and extrapolating from an erroneous
    model that you dreamed up from partial information. You may be smart in
    some ways, but if you were wise, you would know that your believing
    something doesn't make it real.

    As for those snide remarks you want to deflect, you earned them with
    your pig-headed pursuit of arrant nonsense. I'm willing to start over,
    but I expect you to shape up.

    Jerry
    --
    Engineering is the art of making what you want from things you can get.
    ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
    Jerry Avins, Aug 20, 2007
    #4
  5. Radium

    Radium Guest

    On Aug 19, 2:50 pm, (Ray Fischer) wrote:

    > Radium <> 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?

    What is the video-equivalent of bit-resolution?

    > 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?

    > >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?

    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.

    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?
    Radium, Aug 20, 2007
    #5
  6. (Ray Fischer) wrote:
    >Radium <> wrote:
    >>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.


    But that was not the question. The analog-equivalent is
    bandwidth.

    In a purely analog channel frequencies higher than the
    upper limit of the channel's bandwidth will not be
    passed. When using a digital channel no analog signal
    frequencies higher than 1/2 the Nyquist rate (i.e., the
    sampling rate) will be passed.

    Granted, that with an analog channel the limit is never
    a sharply defined frequency; hence in practice there is
    not a instant cutoff, but rather a number of negative
    effects that become more significant as the signal
    frequency approaches and goes beyond the arbitrarily set
    "upper limit". Generally phase distortion increases and
    signal level decreases, for example. The upper limit is
    a function of how much distortion is acceptable for the
    application.

    In a digital channel you cannot pass frequencies higher
    1/2 the Nyquist rate, which in theory is a very sharp
    cutoff but in practice it becomes very similar to the
    gradual analog cutoff. The reason for that the extreme
    negative effects associated with distortion of inputs
    that are above that frequency virtually always require
    analog filters at the input to absolutely avoid any
    frequencies above 1/2 the Nyquist rate. (Alias
    frequencies are generated at the output rather than a
    signal which is the same as the input, and the
    distortion is 100%. ) Hence analog filters that have the
    exact same effects as would be seen with an analog
    channel are used at the input of an analog to digital
    conversion.

    --
    Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
    Ukpeagvik (Barrow, Alaska)
    Floyd L. Davidson, Aug 20, 2007
    #6
  7. Radium

    Radium Guest

    On Aug 19, 4:39 pm, Jerry Avins <> wrote:

    > Radium wrote:


    > > 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.


    This would be a start if I want to decrease the frequency of a video
    signal without decreasing the playback speed.

    The application here is to change the frequency of the video signal
    without altering the frame-rate, sample-rate, or tempo of the video
    signal.

    This is like changing the pitch of audio on playback without modifying
    the sample-rate or playback speed.

    Adobe Audition provides this affect.

    Using this software, you can also change the tempo of a song without
    affecting the pitch.

    > As for bit resolution, what does
    > that term mean to you? I think it means the number of bits used to
    > represent each sample, whatever the situation.


    Same here. In audio, a greater bit-resolution provides more levels of
    loudness that a smaller bit-resolution. In video, what does a greater
    bit-resolution provide that a smaller bit-resolution doesn't? More
    levels of light intensity? More colors? I am just guessing.

    > > Digital linear PCM audio has the following components:


    > > 3. Bit-resolution [16-bit for CD audio]


    > So you do know what the term means.


    Yes. I know what it means. However, I don't know what its video-
    equivalent is?

    > > 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? In an
    > > analog audio device, does this equivalent need to be at least 2x the
    > > highest intended frequency of the analog audio signal? If not, then
    > > what is the minimum frequency that the analog-equivalent-of-sample-
    > > rate must be in relation to the analog audio signal?


    > There are no samples in an analog system, so there is no sample rate.


    Okay. Then what is the analog-equivalent of a "sample"?

    The analog-equivalent of bit-resolution = dynamic range

    The analog-equivalent of sample rate = ?

    > http://www.dspguru.com/


    Thanks for the link
    Radium, Aug 20, 2007
    #7
  8. Radium

    Jerry Avins Guest

    Radium wrote:

    ...

    > Okay. So a digital video device with greater bit-resolution can allow
    > for more levels of luminance?


    Ir color differentiation. Or both.
    \
    > What is the video-equivalent of bit-resolution?


    Bit resolution.

    ...

    > There is no analog-equivalent of sample-rate? Then what the limits the
    > highest frequency an analog audio device can encode?


    The capabilities of the transmission and recording media.

    > What determines the highest frequency signal an analog solid-state
    > audio device can input without distortion?


    Distortion, in the commonly used sense is immaterial. On a phonograph
    disk, high frequencies are limited by the ability of the cutting stylus
    to move rapidly, of the playback stylus to stay in the groove at high
    acceleration, and of the microphone to capture the sound.

    > Analog solid-state audio device = a purely analog electronic device
    > that can record, store, playback, and process audio signals without
    > needing any moving parts.


    Oh? Just what would the record consist of?

    > 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.


    All true. How to you record it with no moving parts? Even a microphone
    has a moving diaphragm. You must like the taste of your foot. You keep
    putting it in your mouth.

    > What mathematically determines the highest-frequency electric signal
    > such a device can intake without distortion?


    Distortion (as the term is commonly meant unless otherwise qualified)
    entails harmonics which have higher frequencies than that which is
    distorted. Near a system's upper frequency limit, harmonic distortion is
    impossible. There is no mathematical limit to an analog system's
    frequency response; the limit is physical. One can understand purely
    digital systems with mathematics alone. Analog systems are messier by
    far. You actually have to understand how real-world things behave in
    order to deal with them. Purely digital systems have relatively little
    use. All of our senses are analog.

    Jerry
    --
    Engineering is the art of making what you want from things you can get.
    ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
    Jerry Avins, Aug 20, 2007
    #8
  9. Radium

    Jerry Avins Guest

    Radium wrote:
    > On Aug 19, 4:39 pm, Jerry Avins <> wrote:
    >
    >> Radium wrote:

    >
    >>> 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.

    >
    > This would be a start if I want to decrease the frequency of a video
    > signal without decreasing the playback speed.


    Various compression schemes do that with varying degrees of resulting
    quality.

    > The application here is to change the frequency of the video signal
    > without altering the frame-rate, sample-rate, or tempo of the video
    > signal.
    >
    > This is like changing the pitch of audio on playback without modifying
    > the sample-rate or playback speed.


    No it's like compressing the bit rate; MP3, for example.

    > Adobe Audition provides this affect.
    >
    > Using this software, you can also change the tempo of a song without
    > affecting the pitch.
    >
    >> As for bit resolution, what does
    >> that term mean to you? I think it means the number of bits used to
    >> represent each sample, whatever the situation.

    >
    > Same here. In audio, a greater bit-resolution provides more levels of
    > loudness that a smaller bit-resolution. In video, what does a greater
    > bit-resolution provide that a smaller bit-resolution doesn't? More
    > levels of light intensity? More colors? I am just guessing.


    Both

    >>> Digital linear PCM audio has the following components:

    >
    >>> 3. Bit-resolution [16-bit for CD audio]

    >
    >> So you do know what the term means.

    >
    > Yes. I know what it means. However, I don't know what its video-
    > equivalent is?
    >
    >>> 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? In an
    >>> analog audio device, does this equivalent need to be at least 2x the
    >>> highest intended frequency of the analog audio signal? If not, then
    >>> what is the minimum frequency that the analog-equivalent-of-sample-
    >>> rate must be in relation to the analog audio signal?

    >
    >> There are no samples in an analog system, so there is no sample rate.

    >
    > Okay. Then what is the analog-equivalent of a "sample"?


    There is none.

    > The analog-equivalent of bit-resolution = dynamic range
    >
    > The analog-equivalent of sample rate = ?


    Bandwidth.

    >> http://www.dspguru.com/

    >
    > Thanks for the link


    Use it. Get facts and stop reasoning from false analogies. If you want
    to know how many angels can dance on the head of a pin, build a better
    microscope. Aquinas can't tell you, and you can't deduce the answer.

    Jerry
    --
    Engineering is the art of making what you want from things you can get.
    ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
    Jerry Avins, Aug 20, 2007
    #9
  10. Radium

    Radium Guest

    On Aug 19, 5:55 pm, Jerry Avins <> wrote:

    > Radium wrote:


    > > Okay. So a digital video device with greater bit-resolution can allow
    > > for more levels of luminance?


    > Ir color differentiation. Or both.


    Huh?

    > > 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.


    > All true. How to you record it with no moving parts?


    Other than the microphone [obviously], why does there need to be any
    moving parts? If a digital audio device can play audio back without
    any moving parts, why can't an analog audio device be designed to do
    the same?

    The device below is *not* analog. It uses sampling so its digital:

    http://www.winbond-usa.com/mambo/content/view/36/140/

    I'm curious to why there are no purely-analog devices which can
    record, store, and playback electric audio signals [AC currents at
    least 20 Hz but no more than 20,000 Hz] without having moving parts.
    Most of those voice recorders that use chips [i.e. solid-state] are
    digital. Analog voice recorders, OTOH, use cassettes [an example of
    "moving parts"].
    Radium, Aug 20, 2007
    #10
  11. Radium

    Radium Guest

    On Aug 19, 6:08 pm, Jerry Avins <> wrote:

    > Radium wrote:


    > > This would be a start if I want to decrease the frequency of a video
    > > signal without decreasing the playback speed.


    > Various compression schemes do that with varying degrees of resulting
    > quality.


    I am talking about:

    1. Decreasing the temporal frequency of the video signal without low-
    pass filtering or decreasing the playback speed - an example of which
    would be decreasing the rate at which a bird [in the movie] flaps its
    wings. Hummingbirds flap their wings too fast for the human eye to
    see. So the flap-rate of the wings could be decreased until the
    flapping is visible to the human eye - without decreasing the playback
    speed of the video. This decrease in flap-rate without slowing
    playback is visually-analogous to decreasing the pitch of a recorded
    sound without decreasing the playback speed. In this case, low-pass
    filter would involve attenuating rapidly-changing images while
    amplifying slowly-changing images -- I don't want this.

    2. Decreasing the spatial frequency of the images in the video-signal
    without low-pass filtering the images or increasing their sizes. An
    example of this would be making the sharp areas of an image look
    duller without decreasing the "sharpness" setting [an example of low-
    pass filtering] on the monitor or increasing the size of the image.
    Normally, when the size of an image is decreased, its sharpness
    increases [it's like compressing a lower-frequency sound wave into a
    higher-frequency one]. Likewise, when the size of an image is
    increased, it looks duller [like stretching a higher-frequency sound
    wave into a lower-frequency one]. Low-pass filtering simply decreasing
    the sharpness of an image while increasing its dull characteristics --
    which is what I don't want.

    #1 Decreases the rate at which objects in the video move without
    decreasing the video's playback speed or eliminating originally-
    rapidly-moving objects [such as the rapidly flapping wings]

    #2 Decreases makes a still image less sharp by stretching everything
    within the image without increasing the size of the image or
    eliminating sharp portions of the original image

    Both #1 and #2 are visual-equivalents of decreasing the pitch of a
    recorded audio signal without decreasing the audio's playback speed.
    Radium, Aug 20, 2007
    #11
  12. Radium

    Jerry Avins Guest

    Radium wrote:
    > On Aug 19, 5:55 pm, Jerry Avins <> wrote:


    ...

    >> Ir color differentiation. Or both.

    >
    > Huh?


    Typo: Or color differentiation. Or both.

    >>> 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.

    >
    >> All true. How to you record it with no moving parts?

    >
    > Other than the microphone [obviously], why does there need to be any
    > moving parts? If a digital audio device can play audio back without
    > any moving parts, why can't an analog audio device be designed to do
    > the same?


    Describe a motion-free process of recording and playing back. Cutting
    grooves on a disk or magnetizing a moving tape both involve motion.

    > The device below is *not* analog. It uses sampling so its digital:
    >
    > http://www.winbond-usa.com/mambo/content/view/36/140/
    >
    > I'm curious to why there are no purely-analog devices which can
    > record, store, and playback electric audio signals [AC currents at
    > least 20 Hz but no more than 20,000 Hz] without having moving parts.
    > Most of those voice recorders that use chips [i.e. solid-state] are
    > digital. Analog voice recorders, OTOH, use cassettes [an example of
    > "moving parts"].


    It's this simple: nobody has invented a way. I doubt than anyone ever
    will. If you know how, communicate with me privately. With your idea and
    my ability to bring it to fruition, we'll both get rich. A motion-free
    method for printing text would also be a money maker.

    Jerry
    --
    Engineering is the art of making what you want from things you can get.
    ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
    Jerry Avins, Aug 20, 2007
    #12
  13. Radium

    Jerry Avins Guest

    Radium wrote:
    > On Aug 19, 6:08 pm, Jerry Avins <> wrote:
    >
    >> Radium wrote:

    >
    >>> This would be a start if I want to decrease the frequency of a video
    >>> signal without decreasing the playback speed.

    >
    >> Various compression schemes do that with varying degrees of resulting
    >> quality.

    >
    > I am talking about:
    >
    > 1. Decreasing the temporal frequency of the video signal without low-
    > pass filtering or decreasing the playback speed - an example of which
    > would be decreasing the rate at which a bird [in the movie] flaps its
    > wings. Hummingbirds flap their wings too fast for the human eye to
    > see. So the flap-rate of the wings could be decreased until the
    > flapping is visible to the human eye - without decreasing the playback
    > speed of the video. This decrease in flap-rate without slowing
    > playback is visually-analogous to decreasing the pitch of a recorded
    > sound without decreasing the playback speed. In this case, low-pass
    > filter would involve attenuating rapidly-changing images while
    > amplifying slowly-changing images -- I don't want this.


    You convinced me: there are stupid questions. Video and movies work by
    displaying a succession of still pictures close enough together in time
    and and position to give us the illusion of continuous motion. Think
    about how slow motion is accomplished with film photography. Speculate
    about how this might be done with analog video, and extrapolate to
    digitized video.

    > 2. Decreasing the spatial frequency of the images in the video-signal
    > without low-pass filtering the images or increasing their sizes. An
    > example of this would be making the sharp areas of an image look
    > duller without decreasing the "sharpness" setting [an example of low-
    > pass filtering] on the monitor or increasing the size of the image.
    > Normally, when the size of an image is decreased, its sharpness
    > increases [it's like compressing a lower-frequency sound wave into a
    > higher-frequency one]. Likewise, when the size of an image is
    > increased, it looks duller [like stretching a higher-frequency sound
    > wave into a lower-frequency one]. Low-pass filtering simply decreasing
    > the sharpness of an image while increasing its dull characteristics --
    > which is what I don't want.


    That's a reasonable summary of what you don't want to do. What do you
    think you might do instead?

    > #1 Decreases the rate at which objects in the video move without
    > decreasing the video's playback speed or eliminating originally-
    > rapidly-moving objects [such as the rapidly flapping wings]


    Something has to give. If the flapping of the wings is slowed, so is the
    motion of everything else.

    > #2 Decreases makes a still image less sharp by stretching everything
    > within the image without increasing the size of the image or
    > eliminating sharp portions of the original image


    Huh?

    > Both #1 and #2 are visual-equivalents of decreasing the pitch of a
    > recorded audio signal without decreasing the audio's playback speed.


    Says who? You're reasoning from false analogy again.

    Jerry
    --
    Engineering is the art of making what you want from things you can get.
    ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
    Jerry Avins, Aug 20, 2007
    #13
  14. Radium

    Radium Guest

    On Aug 19, 7:47 pm, Jerry Avins <> wrote:

    > Radium wrote:


    > > Other than the microphone [obviously], why does there need to be any
    > > moving parts? If a digital audio device can play audio back without
    > > any moving parts, why can't an analog audio device be designed to do
    > > the same?


    > Describe a motion-free process of recording and playing back. Cutting
    > grooves on a disk or magnetizing a moving tape both involve motion.


    The iPod is motion-free yet it's still able to record and playback.

    Those Nintendo Entertainment System cartridges were able to playback
    without any motion.

    > > The device below is *not* analog. It uses sampling so its digital:


    > >http://www.winbond-usa.com/mambo/content/view/36/140/


    > > I'm curious to why there are no purely-analog devices which can
    > > record, store, and playback electric audio signals [AC currents at
    > > least 20 Hz but no more than 20,000 Hz] without having moving parts.
    > > Most of those voice recorders that use chips [i.e. solid-state] are
    > > digital. Analog voice recorders, OTOH, use cassettes [an example of
    > > "moving parts"].


    > It's this simple: nobody has invented a way. I doubt than anyone ever
    > will. If you know how, communicate with me privately.


    I don't know how but I guessing that it involves the analog equivalent
    of Flash RAM [if re-writing is desired] or the analog equivalent of
    Masked-ROM [if permanent storage is desired].
    Radium, Aug 20, 2007
    #14
  15. Radium

    Sjouke Burry Guest

    Radium wrote:
    > On Aug 19, 7:47 pm, Jerry Avins <> wrote:
    >
    >> Radium wrote:

    >
    >>> Other than the microphone [obviously], why does there need to be any
    >>> moving parts? If a digital audio device can play audio back without


    Ah Radium trolling again i see!!!!
    Sjouke Burry, Aug 20, 2007
    #15
  16. Radium

    Ron N. Guest

    someone wrote:
    > There is no analog-equivalent of sample-rate? Then what the limits the
    > highest frequency an analog audio device can encode?
    >
    > What determines the highest frequency signal an analog solid-state
    > audio device can input without distortion?


    The basic physics of material objects leads to some
    limitations. At some frequency, a given force can
    no longer accelerate the mass of a given physical
    transducer or recording substance by an amount
    greater than does thermal noise (and other sources
    of noise, such as friction, wear, dust, magnetic
    particle size, film grain size, etc.)
    Ron N., Aug 20, 2007
    #16
  17. Radium

    Bob Myers Guest

    Radium <> wrote:

    >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?


    What you are calling "bit resolution" is more commonly
    referred to as bits/sample, or in video bits/color or per
    component. It "enters into the equation" in all digital
    encoding systems by setting the dynamic range that can
    be encoded in that system, or, if you prefer, the "accuracy"
    with which each sample represents the value of the original
    signal at that point. The number of bits, along with the choice
    of the maximum value which can be encoded (i.e., what level
    "all ones" in the sample corresponds to) determines the value
    represented by the least-significant bit.

    >>
    >>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]


    PCM has nothing to do with it.

    >>Sample rate in audio = frame rate in video


    No. There is no real analog, in audio, to the frame
    rate in video, except to the extent that the frame rate
    IS a sample rate in terms of capturing one complete
    2-D image at that point in time - IF that is the way the
    image capture device works (and not all work this way).
    More typically, the "sample rate" in audio would be
    thought of as corresponding to the pixel rate in video.

    >>Channel in audio = pixel in video


    Definitely not. A "pixel" in imaging is just what the
    name says - it is a "picture element," meaning one
    dimensionless point-sample of the original image, at
    a specific location within the image plane and, in the
    case of motion video, at a specific time. A pixel is
    the best analog you will find to a single sample in
    the case of digital audio.

    >>Bit-resolution in audio = ? in video


    Bits per sample is bits per sample, in either case.

    >>Is it true that unlike the-frequency-of-audio, the-frequency-of-video
    >>has two components -- temporal and spatial?


    A better way to say this is that you are concerned
    with both temporal and spatial frequencies in the case of
    motion video. (And, in the case of still images - as in
    digital still photography - spatial frequencies only.)

    >>II. Digital vs. Analog
    >>
    >>Sample-rate is a digital entity.


    Not really. While today most sampled systems are, in fact,
    "digital" in nature (meaning that the information is encoded in
    digital form), there is nothing in sampling theory which restricts
    its applicability to that realm. Sampled analog systems are certainly
    not very common today (unless you count certain forms of
    modulation as "sampling," and in fact there are some very close
    parallels there), but the theory remains the same no matter which
    form of encoding is used. In any event, you must sample the
    original signal at a rate equal to at least twice its bandwidth (actually,
    very slightly higher, to avoid a particular degenerate case which
    could occur at EXACTLY 2X the bandwidth) in order to preserve
    the information in the original and avoid "aliasing."

    Bob M.
    Bob Myers, Aug 20, 2007
    #17
  18. Radium

    Jerry Avins Guest

    Radium wrote:
    > On Aug 19, 7:47 pm, Jerry Avins <> wrote:
    >
    >> Radium wrote:

    >
    >>> Other than the microphone [obviously], why does there need to be any
    >>> moving parts? If a digital audio device can play audio back without
    >>> any moving parts, why can't an analog audio device be designed to do
    >>> the same?

    >
    >> Describe a motion-free process of recording and playing back. Cutting
    >> grooves on a disk or magnetizing a moving tape both involve motion.

    >
    > The iPod is motion-free yet it's still able to record and playback.


    It does that digitally. Did you really not know that? Are you trolling
    after all?

    > Those Nintendo Entertainment System cartridges were able to playback
    > without any motion.


    It does that digitally. Did you really not know that? Are you trolling
    after all?

    >>> The device below is *not* analog. It uses sampling so its digital:

    >
    >>> http://www.winbond-usa.com/mambo/content/view/36/140/

    >
    >>> I'm curious to why there are no purely-analog devices which can
    >>> record, store, and playback electric audio signals [AC currents at
    >>> least 20 Hz but no more than 20,000 Hz] without having moving parts.
    >>> Most of those voice recorders that use chips [i.e. solid-state] are
    >>> digital. Analog voice recorders, OTOH, use cassettes [an example of
    >>> "moving parts"].

    >
    >> It's this simple: nobody has invented a way. I doubt than anyone ever
    >> will. If you know how, communicate with me privately.

    >
    > I don't know how but I guessing that it involves the analog equivalent
    > of Flash RAM [if re-writing is desired] or the analog equivalent of
    > Masked-ROM [if permanent storage is desired].


    What would you write into that "RAM"? There are no analog bits. The
    analog equivalent of a masked ROM is a phonograph record. Think first.
    Blather afterward, but show some sign of thought or you're not worth
    bothering with.

    Jerry
    --
    Engineering is the art of making what you want from things you can get.
    ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
    Jerry Avins, Aug 20, 2007
    #18
  19. Radium

    Jerry Avins Guest

    Bob Myers wrote:

    > ... you must sample the
    > original signal at a rate equal to at least twice its bandwidth (actually,
    > very slightly higher, to avoid a particular degenerate case which
    > could occur at EXACTLY 2X the bandwidth) in order to preserve
    > the information in the original and avoid "aliasing."


    Bob,

    The degenerate case is just a limit. Signals close to the band edge take
    a long time to be resolved. The time is of the order if 1/|f-F|, where F
    is the frequency of the nearer band edge. Just as it takes in the order
    of 100 seconds to resolve a frequency of .01 Hz, it takes the same time
    to resolve a frequency of Fs/2 - .01 Hz. When f = Fs/2, it just takes
    forever. The real works tends to be continuous.

    Jerry
    --
    Engineering is the art of making what you want from things you can get.
    ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
    Jerry Avins, Aug 20, 2007
    #19
  20. Radium

    Dave Platt Guest

    In article <>,
    Radium <> wrote:

    >I'm curious to why there are no purely-analog devices which can
    >record, store, and playback electric audio signals [AC currents at
    >least 20 Hz but no more than 20,000 Hz] without having moving parts.
    >Most of those voice recorders that use chips [i.e. solid-state] are
    >digital. Analog voice recorders, OTOH, use cassettes [an example of
    >"moving parts"].


    The fact that it's an AC (inherently-varying) signal being recorded,
    means that *something* has to move... if only some amount of
    electrical charge. If the electrons don't move, the output can't vary
    and all you have is a DC voltage.

    And, in fact, this concept of moving electrical charges is the basis
    for one type of analog signal storage and playback device which has no
    moving (mechanical) parts... the CCD, or Charge Coupled Device. It
    consists of a large number of charge storage devices (typically MOSFET
    transistors with dielectrically-isolated gates) hooked up as a sort of
    shift register or "bucket brigade". Each gate stores a charge which
    is proportional to the input signal present at a given moment in time.
    Several thousand times per second, a clock pulse causes each storage
    cell to generate an output voltage proportional to the charge in its
    storage gate, and then to "capture" onto its gate the signal being
    presented by the previous gate in the chain.

    In effect, the signal is propagated down the chain at a rate
    proportional to the clock rate.

    Why aren't these devices used more than they are? They're not very
    efficient, and they're noisy. Every time the charge is copied from
    one cell to the next, a bit of imprecision (noise) creeps in... so the
    fidelity isn't great. And, because the device has to be able to hold
    a very wide range of charges (since the charge is directly
    proportional to the signal level) the storage gates have to be fairly
    large.

    The net result is that an audio CCD is capable of storing a
    decent-quality signal for only a few tens or hundreds of milliseconds,
    from input to output.

    Another sort of a purely analog signal-storage device, with no moving
    parts other than the electrons which convey the signal, is a simple
    length of transmission line (with perhaps some amplifiers mid-way).
    Put a signal in at one end, get the same signal back out the other end
    some number of microseconds or milliseconds later.

    Once again, they're not terribly efficient and are prone to be noisy.

    For storage of large amounts of information, in a small space, with
    high fidelity, using digital storage techniques is much more
    efficient - largely because each storage cell must only store 2
    different information states (0 and 1) rather than a large number of
    possible levels.

    --
    Dave Platt <> AE6EO
    Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
    I do _not_ wish to receive unsolicited commercial email, and I will
    boycott any company which has the gall to send me such ads!
    Dave Platt, Aug 20, 2007
    #20
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