Jerry Avins <jya@ieee.org> wrote in message news:<3fdfccea$0$4752$61fed72c@news.rcn.com>...> I give up.Me too. I now realize that digital information cannot be less that one bit. I must admit this is one of my stupid threads which I started w/out sufficient research. Sorry.
Bit-resolution decrease for internet
Started by ●December 3, 2003
Reply by ●December 21, 20032003-12-21
Reply by ●December 21, 20032003-12-21
Radium wrote:> Jerry Avins <jya@ieee.org> wrote in message > news:<3fdfccea$0$4752$61fed72c@news.rcn.com>... >> I give up. > > Me too. I now realize that digital information cannot be less that one > bit.Congratulations. Ben -- A7N8X FAQ: www.ben.pope.name/a7n8x_faq.html Questions by email will likely be ignored, please use the newsgroups. I'm not just a number. To many, I'm known as a String...
Reply by ●December 23, 20032003-12-23
glucegen@excite.com (Radium) wrote in message news:<yvik75eq9k7.fsf@jpff.cs.bath.ac.uk>...> I would like to use an audio codec based on WAVE PCM. It should be a > little different though. The bit-resolution should be set to equal > 1/(sampling rate X # of channels). The bit-rate should be set to equal > 1 bit per second. I would like to use this codec to transport audio > files though the internet via email. > > I am looking for frequency response. In digital audio the sampling > rate must be at least twice the highest frequency in the signal. It > would like a highest frequency of at least 200 KHz. This would require > a sample rate of at least 400 KHz. > > In this codec the bit-resolution is decreased to maintain a low bit > rate of 1 bit/sec. The bit-resolution is divided by the sampling rate > and the # of channels to acheive this.From the responses to my above message I found it is impossible to have less than 1-bit/sample. After the bit is the quantum of digital info. What about sampling rate? Is it possible to have less than 1 sample/bit? Lets say a codec with: Sample rate = 1/(bit resolution X number of channels) Since: bit-rate = sample rate X bit-resolution X number of channels, The sample rate would cancel with the bit-resolution and # of channels. After all AB X 1/AB = 1 Plug in CD quality bit resolution (16-bit) and # of channels (2), sample rate = 1/32 = 0.03125 Hz I know this codec would be impractical but is it possible? I'm just in it for the science. No application.
Reply by ●December 23, 20032003-12-23
Radium wrote:> > glucegen@excite.com (Radium) wrote in message news:<yvik75eq9k7.fsf@jpff.cs.bath.ac.uk>... > > I would like to use an audio codec based on WAVE PCM. It should be a > > little different though. The bit-resolution should be set to equal > > 1/(sampling rate X # of channels). The bit-rate should be set to equal > > 1 bit per second. I would like to use this codec to transport audio > > files though the internet via email. > > > > I am looking for frequency response. In digital audio the sampling > > rate must be at least twice the highest frequency in the signal. It > > would like a highest frequency of at least 200 KHz. This would require > > a sample rate of at least 400 KHz. > > > > In this codec the bit-resolution is decreased to maintain a low bit > > rate of 1 bit/sec. The bit-resolution is divided by the sampling rate > > and the # of channels to acheive this. > > From the responses to my above message I found it is impossible to > have less than 1-bit/sample. After the bit is the quantum of digital > info. > > What about sampling rate? Is it possible to have less than 1 > sample/bit? > > Lets say a codec with: > > Sample rate = 1/(bit resolution X number of channels) > > Since: > > bit-rate = sample rate X bit-resolution X number of channels, > > The sample rate would cancel with the bit-resolution and # of > channels. > > After all AB X 1/AB = 1 > > Plug in CD quality bit resolution (16-bit) and # of channels (2), > > sample rate = 1/32 = 0.03125 Hz > > I know this codec would be impractical but is it possible? > > I'm just in it for the science. No application.In the very remote past, "Ug" took a sample of the La Brea tar pits, and died in the muck. He never took another sample, and that was thousands of years ago. How is *that* for a sample rate??? Actually, in real life, photographers have used one sample per day with a movie camera, to show the growth of a plant. Also, a sample rate of once every 15 minutes (i am guessing) to show a flower opening in the morning, turning to follow the sun, and closing at night. Another real case: to show cloud movement over a day or many days.
Reply by ●December 23, 20032003-12-23
Radium wrote:> glucegen@excite.com (Radium) wrote in message news:<yvik75eq9k7.fsf@jpff.cs.bath.ac.uk>... > >>I would like to use an audio codec based on WAVE PCM. It should be a >>little different though. The bit-resolution should be set to equal >>1/(sampling rate X # of channels). The bit-rate should be set to equal >>1 bit per second. I would like to use this codec to transport audio >>files though the internet via email. >> >>I am looking for frequency response. In digital audio the sampling >>rate must be at least twice the highest frequency in the signal. It >>would like a highest frequency of at least 200 KHz. This would require >>a sample rate of at least 400 KHz. >> >>In this codec the bit-resolution is decreased to maintain a low bit >>rate of 1 bit/sec. The bit-resolution is divided by the sampling rate >>and the # of channels to acheive this. > > > > From the responses to my above message I found it is impossible to > have less than 1-bit/sample. After the bit is the quantum of digital > info.The beginning of wisdom> What about sampling rate? Is it possible to have less than 1 > sample/bit?Of course. With 16-bit samples, you could say that there is 1/16 of a sample per bit. (I don't think you meant to ask that.)> Lets say a codec with: > > Sample rate = 1/(bit resolution X number of channels)No. Sample rate of a channel is more than 2 X maximum frequency to be carried by that channel. It doesn't depend on the number of bits in a sample. It doesn't depend on how many other channels there are.> Since: > > bit-rate = sample rate X bit-resolution X number of channels, > > The sample rate would cancel with the bit-resolution and # of > channels.The same bull. Garbage in, garbage out. With a false assumption, you can "prove" anything at all. Pick arbitrary numbers for illustration (telephone quality): Bit resolution: 12 bits per sample No. of channels: 1 Sample rate: 8,000/second (to allow frequencies up to 4 KHz.) The bit rate is 96,000 bits/second. Now make it stereo: Bit resolution: 12 bits per sample No. of channels: 2 Sample rate: 8,000/second (to allow frequencies up to 4 KHz.) This bit rate works out to 192,000 bits/second, not 48,000.> After all AB X 1/AB = 1True for any AB.> Plug in CD quality bit resolution (16-bit) and # of channels (2), > > sample rate = 1/32 = 0.03125 HzIn which case, the maximum channel frequency is 1/64 - .015625 Hz, less than one cycle per minute. What will you send on it? (The first Trans- atlantic telegraph cable turned out that way. It was an unpleasant surprise.)> I know this codec would be impractical but is it possible?1/64 Hz. is possible, but CD quality it isn't.> I'm just in it for the science. No application.Not science. Not even Science Fiction. You need to start over. You seem to be confusing the bit rate of a medium -- wire, CD, multiplexed carrier -- with the bit rate of a single channel. Whatever the requirements for a single channel, the requirements for two together are double that. You conclude they are half. That's wrong. It is true that in order to fit two channels where one had been before, each of the new ones can have only half that of the original. That makes each worse, not better. Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
Reply by ●December 24, 20032003-12-24
Jerry Avins <jya@ieee.org> wrote in message news:<3fe870cf$0$4745$61fed72c@news.rcn.com>...> > Lets say a codec with: > > > > Sample rate = 1/(bit resolution X number of channels) > > No. Sample rate of a channel is more than 2 X maximum frequency to be > carried by that channel.Correct.> It doesn't depend on the number of bits in a > sample. It doesn't depend on how many other channels there are.Of course, it doesn't. sample rate = bitrate/(bit-resolution X number of channels) In CDs, 44100 = 1411200/(16 X 2) However, a software could be programmed to make the sample rate = 1/(bit-resolution X number of channels). Right? Using the bit-resolution and number of channels present in CDs and the above programmed codec, Sample rate = 1/(16 X 2) = 1/32 = 0.03125 Hz
Reply by ●December 24, 20032003-12-24
> > > Lets say a codec with: > > > > > > Sample rate = 1/(bit resolution X number of channels) > > > > No. Sample rate of a channel is more than 2 X maximum frequency to be > > carried by that channel. > > Correct. > > > It doesn't depend on the number of bits in a > > sample. It doesn't depend on how many other channels there are. > > Of course, it doesn't. > > sample rate = bitrate/(bit-resolution X number of channels) > > In CDs, > > 44100 = 1411200/(16 X 2) > > However, a software could be programmed to make the sample rate = > 1/(bit-resolution X number of channels). Right? > > Using the bit-resolution and number of channels present in CDs and the > above programmed codec, > > Sample rate = 1/(16 X 2) = 1/32 = 0.03125 HzOfcourse you can have some arbitrary bit rate and then match a sample rate etc to it. However I see little point in doing so... normally you have some actual analog signal that you wish to digitise. That signal will have some intelligence on it... and that intelligence will cover a particular bandwidth. You MUST now choose a sampling rate that is atleast twice the bandwidth of the intelligence to gain an intelligible digital recreation of the original signal. If you choose a sample rate less than twice the intelligence bandwidth then you will run into problems with aliasing and you'll just end up with a mess of different unexpected frequencies. Now the sample rate is... fs = 2*fi and the bit resolution per sample is bres say the number of channels is n we have bit rate = 2*fi*bres*n It's silly to construct the system around the bit rate, instead the system should be resolved around the remaining three items, intelligence bandwidth, number of channels and required bit resolution. Once the bit rate is found then some data transmission channel should be found that would support such a data transmission speed.
Reply by ●December 24, 20032003-12-24
Radium wrote:> Jerry Avins <jya@ieee.org> wrote in message news:<3fe870cf$0$4745$61fed72c@news.rcn.com>......>>No. Sample rate of a channel is more than 2 X maximum frequency to be >>carried by that channel. > > > Correct. >...> Using the bit-resolution and number of channels present in CDs and the > above programmed codec, > > Sample rate = 1/(16 X 2) = 1/32 = 0.03125 HzThe numbers all work. If you do it that way, you'll be limited to a top frequency less than one cycle per minute. If that sounds good to you, go for it. (It you add enough channels, you could get down to one cycle per day.) Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
Reply by ●December 24, 20032003-12-24
Radium wrote:> In CDs, > > 44100 = 1411200/(16 X 2) > > However, a software could be programmed to make the sample rate = > 1/(bit-resolution X number of channels). Right? > > Using the bit-resolution and number of channels present in CDs and the > above programmed codec, > > Sample rate = 1/(16 X 2) = 1/32 = 0.03125 HzYou have reversed the role of the dependent and independent variables. It's like trying to make time go backwards by putting your car in reverse and using the speed=distance/time equation. -- Jim Thomas Principal Applications Engineer Bittware, Inc jthomas@bittware.com http://www.bittware.com (703) 779-7770 Build a man a fire and he is warm for a day. Set a man on fire and he is warm for the rest of his life!
Reply by ●December 26, 20032003-12-26
glucegen@excite.com (Radium) wrote in news:464c821f.0312210007.28591132 @posting.google.com:> Jerry Avins <jya@ieee.org> wrote in message news:<3fdfccea$0$4752$61fed72c@news.rcn.com>...>> I give up. > > Me too. I now realize that digital information cannot be less that one > bit. I must admit this is one of my stupid threads which I started > w/out sufficient research. Sorry.Tis OK. I have done worse. The willingness to learn should never be stifled. r -- Nothing beats the bandwidth of a station wagon filled with DLT tapes.
