Why do you think it should be? What advantage would it bring? What costs (either in actual $ costs or performance) would using linear PCM require?
How many bits do you think are contained within each "pixel"? What do you think the word "pixel" means, and how is it distinguished from "sample" in the context of digital imaging?
If you divide 1,411,200 by 44,100, what number do you get? What is the significance of this number?
Answer the above questions, and then you'll have your own answer to this one. Why are you so hung up on "linear PCM" as opposed to any of several hundred (at least) other possible encoding schemes?
The same reason audio CDs used linear-PCM video instead of compressed MP3s. MP3 and other compressed formats are inferior in quality to the uncompressed linear-PCM.
Just as linear-PCM audio is better than MP3s, linear-PCM video is better than MPEG video, VC-1 -- or other compressed -- video.
IMHO, VC-1 is even worse than MPEG
It wouldn't have those nasty "jaggies" associated with VC-1 or other compressed video
I agree, linear-PCM video would be more expensive but it wouldn't have those annoying artifacts that occur in compressed video formats.
The lasers required would have to be of shorter wavelength than those used in the writing and reading of conventional DVDs. The wavelength should be 400 nm since thats the "sweet spot" between the advantages of short wavelengths [i.e. less physical space on disc required] and the hazards of ionizing UV radiation. 400 nm is around the shortest wavelength of non-ionizing UV light.
In addition, the disc would have to be somewhat bigger -- around the size of 33-speed phonos -- to accomodate the large data size required for linear-PCM video.
I really don't see this as a major hurdle. What makes it so difficult for the digital video industries to design the above [i.e. 400 nm recording/playback lasers, optical discs the size of 33-speed phonos, and uncompressed linear-PCM video]?
A "pixel" is *definitely* digital. A "sample" can be analog or digital.
32
The bit-rate divided by the sample-rate. What else?
Because -- as I said before -- I don't like the annoying artifacts that occur in compressed video formats. Those nasty pixelations associated with VC-1 -- and other compressed -- video just make me gag.
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The only compressions I am okay with are WMA^ and the *real* WMV I described in the following threads:
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The *real* WMV should have the sampling rates and progressive resolution [pixel X pixel] of the best quality video signal currently existing. In addition, the WMV's sample rates and pixelXpixel format should be exactly the same as the linear-PCM signal it was prior to compression. As for the color-depth [in "bit-resolution"], decrease it all you want and I still won't mind. In fact I am interested in seeing how a movie would look if the WMV's color-depth is reduced so much that the file-size is just 1-bit [regardless of how long the movie is]. But don't you dare decrease the pixel resolution or sample rate, do so and you'll find my vomit all around the room.
^The WMA should be monoaural and its sample rate should at least 44.1 khz which should also be the same sample rate of the signal when it was in linear-PCM prior to compression. I don't mind if the WMA's bit-resolution is compressed so much that the file size falls to just
1-bit [no matter how long the audio is]. Just keep it monoaural and don't change the sample rate.
32 is also the bit-resolution [16-bit] times the number of channels [2, because CD-audio is stereo, and has 2 channels]
16 [i.e. the bit-resolution] X 2 [i.e. stereo channel] = 32
Why linear PCM specifically, though? Why not any of the other uncompressed digital formats? Do you know why linear PCM is used when it IS used?
What storage capacity would be required to store one hour of uncompressed 1920 x 1080 video at 24 bits per pixels and using a 60 Hz progressive-scan format? What bandwidth would be required to broadcast such a signal (or carry it over a cable system), and using what modulation method?
I didn't exactly ask whether or not it would be more expensive
- I was asking you to specifically identify, and hopefully quantify, the added expense. Can you do that?
How did you arrive at that size? What would the storage capacity of such a system be for any of the standard television formats?
Again, you didn't answer the question, and no, a "pixel" is not "definitely digital." "Pixel" is derived from "picture element" - in other words, a *sample* of an image. In imaging (and esp. in video systems) "pixel" and "sample" (at least when used in the context of the image data rather than the display device) are precisely identical. Even then, your answer ("a 'pixel' is definitely digital") has nothing to do with the question "how many bits do you think are contained within each pixel?". In fact, since you seem (based on your answer) to be hung up on the idea that "pixels" ARE "digital," it makes that question all the more relevant. Please answer it, and then you will have cleared up your confusion regarding "bit rate" and "pixel rate."
Which means what? Do you think this might have something to do with the number of bits in each sample? Do you now see how that relates to your confusion regarding pixel rate and bit rate?
And yet you seem to believe that "linear PCM" is the only possible format which would not exhibit those artifacts, without expressing the slightest hint that you understand why this should be so (were it true in the first place, which it isn't). Once again, you have latched onto a buzzword or phrase without the slightest understanding of what it actually implies. Do you enjoy looking this foolish?
Really? What do you think "color depth" or "bit resolution" equates to in terms of the image quality? What will a reduction in this parameter change in the image?
And at some point you may want to look in to the works of Bela Julesz. Things along the lines of textons, the elements of texture perception ...and such.
What uncompressed digital formats -- other than linear PCM -- exist?
It offers the best quality. Imagine what wavetable synth would sound like if it used mp3s in place of Wavs.
Read the thread where some imbecile asks about an "mp3table":
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I never used the term "pixel rate". Pixel is the video equivalent of channel. Stereo audio has two channels. Mono has only one.
I did use the term "sample rate". Sample rate is the rate at which an analog signal is sampled via Pulse-Amplitude Modulation. For CDs, this rate is 44.1 khz. The PAM carrier signal is at a frequency of 44.1 khz.
CD audio has two channels because it is stereo. Each channels has a bit resolution of 16-bit. So in each channel there are 16 bits per sample. Combine the two channels are there are 32 bits per sample.
Once again, I never used the term "pixel rate". I did use the terms "sample rate" and "bit rate".
"Pixel rate" in video = "channel rate" in audio
Both "channel rate" and "pixel rate" and totally meaningless.
Nope. Linear-PCM video can be just as bad as MPEG -- and possibly even worse -- if the image-resolution [in pixel X pixel], the color-depth [bit-resolution], and/or sample rate [in hz] are too low.
Color-depth or "bit-resolution" determines the number of colors that can be displayed. 8-bit video can display a maximum of 2^16 colors [or
256 colors]. IOW, a color-resolution of n-bit means that a maximum of
2^n colors. In audio, the bit-resolution determines how many levels of loudness can be handled [too loud and you get clipping, too soft and you get quantization error].
A decrease the amount of available colors. However, compression of this parameter is done via my "real WMV", the artifacts won't be as ugly as it would be in linear-PCM or any compression other than my "real WMV". Much in the same way the artifacts in a 120 kbps WMA file go un-noticed. In a Wave file, 120 kbps would sound horrible -- this is due to the absence of the perceptual encoding used in WMA. MP3s, and other [non-WMA] compressed audio sound terrible to me. I also hate aliasing so the sample rate for audio must be at least 44,100 hz.
No, you used the term "sample rate." But since in an imaging context (unless subsampling of the chroma components is employed) a pixel IS a sample, the two are equivalent.
1920 refers to the number of pixels per line in one of the standard HDTV formats (the other one having
720 lines of 1280 pixels each). "Progressive scan" refers to a scanning format in which all of the lines in a frame are scanned in order, rather than being divided into separate fields (such as typical 2:1 interlacing, which divides the frame into "odd" and "even" fields, the lines of which must be interleaved to recover the original). Finally, many displays can shows 24 bits/pixel; in color displays, that's the term typically used to refer to an RGB system with 8 bits (256 levels) per color.
I have no idea what this is supposed to mean, but both audio CDs and MP3-format audio files are based on samples of the original audio signal(s).
Transmission or storage? Straight 24 bit/pixel RGB is the most obvious example of an uncompressed digital format, and it certain;y doesn't have to be encoded in a PCM manner.
So your answer is "no, I really don't even know what PCM is," right?
No, the term "pixel" is used in a digital video context interchangeably with "spatial sample." A "channel" is something altogether different. Again, you clearly are completely unfamiliar with the field in which you are trolling.
A "sample rate" is a completely independent question from the modulation system used to encode or transmit information. Sampled systems are no more required to use PAM than your other new favorite buzzword, PCM.
Incorrect. The pixel rate in video is, if anything, most closely related to the more general term "symbol rate" (or "baud rate"), at least to the extent that until you define the number of bits per pixel, the data rate (in bits/second or whatever equivalent unit you like) cannot be determined. Similarly, "sample rate" by itself does not determine the data rate.
That would come as a rather sizable surprise to a large number of professionals (including myself) who deal with digital video interface, etc., issues.
The rest of your post indicates that you should have been able to answer the very questions you were trolling with. I therefore fail to see any point to continuing this discussion.
What is this RGB encoded? Or is RGB a format by itself. AFAIK, RGB simply stands for Red, Green, and Blue. IIRC, RGB can be analog or digital. So I doubt it is a digital format.
Most video -- whether analog or digital -- contains a red signal, a green signal, and a blue signal. When all three colors are lit to full, the result appears white. When none are lit, the result is black.
What is the file extension for the format you are talking about? Is it .rgb? I doubt it
Just like audio files can have .wav, .pcm, and .raw extension, video files should have an equivalent? What are the video equivalents of those extensions?
PCM is digital representation of an analog signal [such as video or audio]
I am simply trying to find out the video equivalents of the terms used in digital audio [e.g. "sample rate"]
If audio uses it, then what is a visual equivalent of it?
I am well aware that sample-rate does not determine data-rate on its own. Sample rate, bit-resolution, and number of channels, put together, are what determine the data rate.
Data rate = sample rate X bit-resolution X number of channels
CD audio data rate: 1,411,200 bits per second CD audio bit resolution: 16-bit CD audio sample rate = 44,100 hz # of channels in CD audio = 2
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