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Author: RadiumRadium Date: Aug 19, 2007 14:01
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
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Author: Ray FischerRay Fischer Date: Aug 19, 2007 14:50
>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
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Author: Ken MaltbyKen Maltby Date: Aug 19, 2007 16:24
"Ray Fischer" sonic.net> wrote in message
news:46c8bb30$0$14150$742ec2ed@news.sonic.net...> Radium 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
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Author: Jerry AvinsJerry Avins Date: Aug 19, 2007 16:39
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?
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Author: RadiumRadium Date: Aug 19, 2007 16:59
On Aug 19, 2:50 pm, rfisc...@ sonic.net (Ray Fischer) wrote:
> Radium 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]
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Author: Floyd L. DavidsonFloyd L. Davidson Date: Aug 19, 2007 17:03
>Radium gmail.com> 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.
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Author: RadiumRadium Date: Aug 19, 2007 17:16
On Aug 19, 4:39 pm, Jerry Avins ieee.org> 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.
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Author: Jerry AvinsJerry Avins Date: Aug 19, 2007 17:55
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.
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Author: Jerry AvinsJerry Avins Date: Aug 19, 2007 18:08
Radium wrote:
> On Aug 19, 4:39 pm, Jerry Avins ieee.org> 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...
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Author: RadiumRadium Date: Aug 19, 2007 18:14
On Aug 19, 5:55 pm, Jerry Avins ieee.org> 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/
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