|
What is the point of digital voice?
That's good. Trying to educate you is like trying to teach a pig to sing. and I thought brian's put downs were good......... |
What is the point of digital voice?
On 2/25/2015 2:30 AM, AndyW wrote:
On 24/02/2015 17:00, Jerry Stuckle wrote: But you forget compression. For instance, unless there is a scene change, the vast majority of a television picture does not change from frame to frame. Even if the camera moves, the picture shifts but doesn't change all that much. Why waste all of that bandwidth resending information the receiver already has? Which is why, on cheaper televisions, the picture tesselates when showing random images such as rain, fire, waterfalls etc. The true test of a quality television is to watch a waterfall or flames and see it pin-sharp. Cheaper TVs use cheap lower-powered decoding systems and for complex images they do not have enough time to fully decode the image before the next frame arrives. Andy Not really true, at least in the United States. All TV's here use the same (proprietary) chipsets to decompress the digital signal. However, it makes a huge difference on the resolution being used, i.e. 720P, 1080P, 1080I, UHD... The difference is in what happens after the signal is decompressed. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
What is the point of digital voice?
On 2/25/2015 1:41 AM, rickman wrote:
On 2/24/2015 7:12 PM, Jerry Stuckle wrote: snip Some compression algorithms (i.e. mp3) remove what they consider is "unimportant". However, the result after decompressing is a poor recreation of the original signal. That is a value judgement which most would disagree with not to mention that your example is not valid. MP3 does not *remove* anything from the signal. It is a form of compression that simply can't reproduce the signal exactly. The use of the term "poor" is your value judgement. Most people would say an MP3 audio sounds very much like the original. Here's a reference - Neil Young and Steve Jobs, no less. http://www.pcmag.com/article2/0,2817,2399710,00.asp -- ================== Remove the "x" from my email address Jerry Stuckle ================== |
What is the point of digital voice?
On Wed, 25 Feb 2015 11:43:09 -0000, "Jim GM4DHJ..."
wrote: You been shot down again. You are hurling abuse, as you always do. Only you thinks otherwise. Everyone else is laughing at you. no we are not...hundreds of us don't give a **** about your one technical upmanship.... WHS |
What is the point of digital voice?
"Jim GM4DHJ..." wrote in
: You been shot down again. You are hurling abuse, as you always do. Only you thinks otherwise. Everyone else is laughing at you. no we are not...hundreds of us don't give a **** about your one technical upmanship.... Too preoccupied with your imagined Morse code one-upmanship? |
What is the point of digital voice?
"gareth" wrote in message
... "Brian Reay" wrote in message ... He struggled with the idea that, as the phasor rotated, the angle became more negative, and thus decreased. eg -20 -10 Brian, is there some truth in G7FUJ, Cum's assertion that you were dismissed without references from your job as a mathematics teacher, for your confusion about a change in direction of a phasor as you express above would be very worrying? When you say "more", in "more negative" above, you are saying that the magnitude of the angle is increasing There seems to be a fundamental problem in your grasp of the direction of vectors, because there is nothing beween clockwise and anti-clockwise, left and right, up and down, or, in this case, negative and positive, for they are merely words used to disambiguate the direction of the vector. Brian, why don't you just give up whilst you are still behind? Brian? Hullo? Are you there? |
What is the point of digital voice?
"gareth" wrote in message ... "Stephen Thomas Cole" wrote in message ... Sadly, Gareth absolutely cannot explain it. He doesn't remotely understand anything he's talking about, as per. If you had but the remorest inkling of the technical matters about which you sneer then you might have some credibility, (although I doubt that anyone has failed to notice that _ALL_ of your posts are nasty personal remarks), but as it is, you add weight to the old adage that empty vessels make the most noise. remorest? typo - remotest |
What is the point of digital voice?
"rickman" wrote in message
... Maybe I don't understand the issue. Isn't that a valid example of a negative frequency? There are some DSP experts in comp.dsp who talk about negative frequency often. If you, or, indeed, anyone else has any difficulties with the subject matter and DSP in general, then do ask me, because having worked through what appeared as a number of anomalies (all resolved 9 years ago when I was working as a DSP manufacturer, picoChip in Bath, UK) I feel sure that I'm well positioned to understand the difficulties that others might encounter in this area. |
What is the point of digital voice?
"gareth" wrote:
"rickman" wrote in message ... Maybe I don't understand the issue. Isn't that a valid example of a negative frequency? There are some DSP experts in comp.dsp who talk about negative frequency often. If you, or, indeed, anyone else has any difficulties with the subject matter and DSP in general, then do ask me, because having worked through what appeared as a number of anomalies (all resolved 9 years ago when I was working as a DSP manufacturer, picoChip in Bath, UK) I feel sure that I'm well positioned to understand the difficulties that others might encounter in this area. WARNING! Make sure to search the archives and read all about his "Big K" theory before taking seriously anything Gareth says about DSP. It'll quickly become apparent that he has no understanding whatsoever of the subject and you'll save yourself from wasting any time talking to him about it. Interestingly, the true experts of comp.dsp refer to Gareth Alun Evans G4SDW as "that idiot from uk.radio.amateur". -- STC // M0TEY // twitter.com/ukradioamateur |
What is the point of digital voice?
If you, or, indeed, anyone else has any difficulties with the subject matter and DSP in general, then do ask me, because having worked through what appeared as a number of anomalies (all resolved 9 years ago when I was working as a DSP manufacturer, picoChip in Bath, UK) I feel sure that I'm well positioned to understand the difficulties that others might encounter in this area. there that shut brian up ! ....... |
What is the point of digital voice?
"gareth" wrote:
"rickman" wrote in message ... Maybe I don't understand the issue. Isn't that a valid example of a negative frequency? There are some DSP experts in comp.dsp who talk about negative frequency often. If you, or, indeed, anyone else has any difficulties with the subject matter and DSP in general, then do ask me, because having worked through what appeared as a number of anomalies (all resolved 9 years ago when I was working as a DSP manufacturer, picoChip in Bath, UK) I feel sure that I'm well positioned to understand the difficulties that others might encounter in this area. No. Don't. Trust me on this. |
What is the point of digital voice?
"Custos Custodum" wrote in message ... "Jim GM4DHJ..." wrote in : You been shot down again. You are hurling abuse, as you always do. Only you thinks otherwise. Everyone else is laughing at you. no we are not...hundreds of us don't give a **** about your one technical upmanship.... Too preoccupied with your imagined Morse code one-upmanship? well you have to do what you are best at ... tee hee...imagination is my speciality.... |
What is the point of digital voice?
On 2/25/2015 11:54 AM, Stephen Thomas Cole wrote:
"gareth" wrote: "rickman" wrote in message ... Maybe I don't understand the issue. Isn't that a valid example of a negative frequency? There are some DSP experts in comp.dsp who talk about negative frequency often. If you, or, indeed, anyone else has any difficulties with the subject matter and DSP in general, then do ask me, because having worked through what appeared as a number of anomalies (all resolved 9 years ago when I was working as a DSP manufacturer, picoChip in Bath, UK) I feel sure that I'm well positioned to understand the difficulties that others might encounter in this area. WARNING! Make sure to search the archives and read all about his "Big K" theory before taking seriously anything Gareth says about DSP. It'll quickly become apparent that he has no understanding whatsoever of the subject and you'll save yourself from wasting any time talking to him about it. Interestingly, the true experts of comp.dsp refer to Gareth Alun Evans G4SDW as "that idiot from uk.radio.amateur". LOL! I see this is cross posted to comp.dsp. I don't feel like researching the "Big K" theory, but I would be interested in hearing a bit if anyone cares to share the humor. -- Rick |
What is the point of digital voice?
On 2/25/2015 3:49 AM, Brian Reay wrote:
On 25/02/15 06:43, rickman wrote: On 2/24/2015 7:32 PM, Brian Reay wrote: Jerry Stuckle wrote: On 2/24/2015 5:47 PM, rickman wrote: On 2/24/2015 12:00 PM, Jerry Stuckle wrote: On 2/24/2015 11:32 AM, FranK Turner-Smith G3VKI wrote: "AndyW" wrote in message ... On 24/02/2015 12:47, gareth wrote: What is the point of digital voice when there are already AM, SSB and FM for those who want to appear indistinguishable from CBers? Perhaps it is cynicism from the manufacturers who introduce such things as they see their traditional highly-priced corner of the market being wiped away by SDR technologies? Bandwidth reduction for one. If you can encode and compress speech sufficiently then you can use less bandwidth in transmission. That's the bit I have trouble getting my head around. Back in the 1970s and 1980s digital transmissions used a much greater bandwidth than their analogue equivalents. Sampling at 2.2 x max frequency x number of bits plus housekeeping bits etc. etc. A UK standard 625 line PAL video transmission would have used a bandwidth of over 400MHz! Times have changed and left me behind, but I've still got me beer so who cares? But you forget compression. For instance, unless there is a scene change, the vast majority of a television picture does not change from frame to frame. Even if the camera moves, the picture shifts but doesn't change all that much. Why waste all of that bandwidth resending information the receiver already has? And voice isn't continuous; it has lots of pauses. Some are very noticeable, while others are so short we don't consciously hear them, but they are there. And once you've compressed everything you can out of the original signal, you can do bit compression, similar to zipping a file for sending. There are lots of ways to compress a signal before sending it digitally. About the only one which can't be compressed is pure white noise - which, of course, is only a concept (nothing is "pure"). I think that depends on what you mean by "pure". Sounds very non-technical to me. Even noise can be compressed since if it is truly noise, you don't need to send the data, just send the one bit that says there is no signal, just noise. lol Pure white noise is a random distribution of signal across the entire spectrum, with an equal distribution of frequencies over time. Like a pure resistor or capacitor, it doesn't exist. But the noise IS the signal. To recreate the noise, you have to sample the signal and transmit it. However, since it is completely random, by definition no compression is possible. To be more accurate, it has an infinite bandwidth and constant power density/Hz. As you say, it doesn't really exist. In practice, lab noise sources are specified over a bandwidth and to be within a given limit of power variation across that. Darn useful devices to have around. So if I have a string of random numbers they can not represent a white noise source of infinite bandwidth and constant power density? Not perfectly. The string would need to be infinitely long and truly random. That is why the term Pseudo Random is generally used for strings used in such applications. Pseudo random applies to finite length sequences. There is nothing to say the string of numbers doesn't extend to infinity. You are confusing the existence of such a string with a representation. The digits of transcendental numbers such as e and pi are expected to be "normal" which is in essence the same as random. So to say that "it doesn't really exist" is not demonstrated in reality much less in theory. I can compress the infinite bit sequence of pi quite easily just by saying... "pi". -- Rick |
What is the point of digital voice?
"Stephen Thomas Cole" wrote in message
... "gareth" wrote: "rickman" wrote in message ... Maybe I don't understand the issue. Isn't that a valid example of a negative frequency? There are some DSP experts in comp.dsp who talk about negative frequency often. If you, or, indeed, anyone else has any difficulties with the subject matter and DSP in general, then do ask me, because having worked through what appeared as a number of anomalies (all resolved 9 years ago when I was working as a DSP manufacturer, picoChip in Bath, UK) I feel sure that I'm well positioned to understand the difficulties that others might encounter in this area. WARNING! Make sure to search the archives and read all about his "Big K" theory before taking seriously anything Gareth says about DSP. It'll quickly become apparent that he has no understanding whatsoever of the subject and you'll save yourself from wasting any time talking to him about it. Interestingly, the true experts of comp.dsp refer to Gareth Alun Evans G4SDW as "that idiot from uk.radio.amateur". You continue to make a fool of yourself by posting nothing but infantile abuse and all your posts lack any evidence of comprehension of technical matters. And your malicious cross-post to comp. dsp is not lost on me; more evidence of your infantile need to draw attention to yourself by stirring things up. By referring to, "Big K", you refer to the anomalies of 10 years and more ago to which I alluded and which were resolved 9 years ago, so what point are you making, exactly? As I said, as I had some difficulties which were resolved, that places me in a good position to assist others who may also have such difficulties. |
What is the point of digital voice?
As I said, as I had some difficulties which were resolved, that places me in a good position to assist others who may also have such difficulties. don't worry about it...teechers don't do nuffin wurfwhile at skool .... |
What is the point of digital voice?
"UK Support" wrote in message
... "gareth" wrote: "rickman" wrote in message ... Maybe I don't understand the issue. Isn't that a valid example of a negative frequency? There are some DSP experts in comp.dsp who talk about negative frequency often. If you, or, indeed, anyone else has any difficulties with the subject matter and DSP in general, then do ask me, because having worked through what appeared as a number of anomalies (all resolved 9 years ago when I was working as a DSP manufacturer, picoChip in Bath, UK) I feel sure that I'm well positioned to understand the difficulties that others might encounter in this area. No. Don't. Trust me on this. If you're intent on making malicious hoaxes, you need to check their name change from 3 years ago. Stupid boy. |
What is the point of digital voice?
"gareth" wrote:
"UK Support" wrote in message ... "gareth" wrote: "rickman" wrote in message ... Maybe I don't understand the issue. Isn't that a valid example of a negative frequency? There are some DSP experts in comp.dsp who talk about negative frequency often. If you, or, indeed, anyone else has any difficulties with the subject matter and DSP in general, then do ask me, because having worked through what appeared as a number of anomalies (all resolved 9 years ago when I was working as a DSP manufacturer, picoChip in Bath, UK) I feel sure that I'm well positioned to understand the difficulties that others might encounter in this area. No. Don't. Trust me on this. If you're intent on making malicious hoaxes, you need to check their name change from 3 years ago. Stupid boy. You caused so much damage to their reputation they had to rebrand? By Jove! -- STC // M0TEY // twitter.com/ukradioamateur |
What is the point of digital voice?
rickman wrote:
On 2/25/2015 11:54 AM, Stephen Thomas Cole wrote: "gareth" wrote: "rickman" wrote in message ... Maybe I don't understand the issue. Isn't that a valid example of a negative frequency? There are some DSP experts in comp.dsp who talk about negative frequency often. If you, or, indeed, anyone else has any difficulties with the subject matter and DSP in general, then do ask me, because having worked through what appeared as a number of anomalies (all resolved 9 years ago when I was working as a DSP manufacturer, picoChip in Bath, UK) I feel sure that I'm well positioned to understand the difficulties that others might encounter in this area. WARNING! Make sure to search the archives and read all about his "Big K" theory before taking seriously anything Gareth says about DSP. It'll quickly become apparent that he has no understanding whatsoever of the subject and you'll save yourself from wasting any time talking to him about it. Interestingly, the true experts of comp.dsp refer to Gareth Alun Evans G4SDW as "that idiot from uk.radio.amateur". LOL! I see this is cross posted to comp.dsp. I don't feel like researching the "Big K" theory, but I would be interested in hearing a bit if anyone cares to share the humor. It all sprang from Gareth being corrected over one of his routine total misunderstandings and he went off the deep end about it, as per, and cooked up "Big K", a Time Cube like confabulation and misrepresentation of known physics. Some time later, after receiving much mocking, he declared that he'd found some obscure textbook (AIUI, nobody has been able to verify the contents of this supposed textbook, or even its existence) that proved that he was correct and that every other person on the planet was wrong and always had been. Thereafter, he refused to be drawn further on "Big K", saying that he had settled the matter "to [his] satisfaction". There's little to be gained from reading Gareth's "Big K" theory, as it's arm-waving nonsense of the highest order. I did challenge him last year to produce a fully referenced paper on the subject that I could review and assess, but he point-blank refused, of course. -- STC // M0TEY // twitter.com/ukradioamateur |
What is the point of digital voice?
"Stephen Thomas Cole" wrote in message
... It all sprang from Gareth being corrected over one of his routine total misunderstandings and he went off the deep end about it, as per, and cooked up "Big K", a Time Cube like confabulation and misrepresentation of known physics. Some time later, after receiving much mocking, he declared that he'd found some obscure textbook (AIUI, nobody has been able to verify the contents of this supposed textbook, or even its existence) that proved that he was correct and that every other person on the planet was wrong and always had been. Thereafter, he refused to be drawn further on "Big K", saying that he had settled the matter "to [his] satisfaction". There's little to be gained from reading Gareth's "Big K" theory, as it's arm-waving nonsense of the highest order. I did challenge him last year to produce a fully referenced paper on the subject that I could review and assess, but he point-blank refused, of course. Once again, your posts are a vehicle for infantile abuse, for, if you had the slightest comprehension of the matters about which you sneer, then you would have at least some credibility, but you merely add weight to the adage that empty vessels make the most noise. For example, in the above, you make no discussion of the technical matters involved and try to mask your ignorance by tirades of abuse. You also lie, for I made no such point-blank refusal., and your continual whingeing on about a peer-reviewed paper was your device for masking your ignorance, for when I enquired of you which bits of my theory that you found fault with, you shuddered to a hallt with your tail between your legs shouting out childish remarks as you ran (pretty much as you do above) Now, Stevie, baby, now that you have widened the circulation to comp.dsp, why not phrase the exact technical issue with which you found difficulty? Perhaps you could start off by explaining the correction to which you allude at the beginning of your rant, above, just to show that you have the merest inkling of the matter, to sace face? |
What is the point of digital voice?
"Stephen Thomas Cole" wrote in message
... You caused so much damage to their reputation they had to rebrand? By Jove! It is unclear from the above as to whether you are speaking for, or against, the motion that you are a technical failure and seek to mask your igorance by using the infantile resort of gratuitous abuse? |
What is the point of digital voice?
On 2/25/15 12:46 PM, Jim GM4DHJ ... wrote:
As I said, as I had some difficulties which were resolved, that places me in a good position to assist others who may also have such difficulties. don't worry about it...teechers don't do nuffin wurfwhile at skool .... yoos to b i cudn't even spel injunear, now i arr won. -- r b-j "Imagination is more important than knowledge." |
What is the point of digital voice?
On Wed, 25 Feb 2015, Stephen Thomas Cole wrote:
Michael Black wrote: On Tue, 24 Feb 2015, gareth wrote: What is the point of digital voice when there are already AM, SSB and FM for those who want to appear indistinguishable from CBers? Perhaps it is cynicism from the manufacturers who introduce such things as they see their traditional highly-priced corner of the market being wiped away by SDR technologies? Because it's something new, at least to amateur radio. The phasing method of sideband was common in the early days of amateur SSB (I recall reading the first rigs were filter type, but with really low IFs, then phasing, then crystal and mechanical filters took over from phasing). It offered up a lot on transmit and receive, though not perfection. But now phasing is used a lot, because digital circuitry has made it viable. I remember seeing some of the potential when phasing was still analog, but I also remember reading articles where it was clear others didn't see the potential. Sometimes ideas become lost when something becomes commonplace. Who knows what would come from digital voice. But I remember 30 years ago one local ham being interested in it, not to the extent of putting something on the air, but as information from the computer world started flowing in, the potential started being there. YOu can't resist new things and say "they have no use", you have to embrace the new and see what can be done with it. Maybe not as initially seen, but maybe it fits in somewhere else. Amateur radio has never done much with envelope elimination and restoration (was that what it was called? I now forget). It's in one of the sideband books, and Karl Meinzer of AMSAT fame wrote about it in QST about 1970. Break the SSB signal into two components, so you can multiply it up to a higher frequency, then modulate the output stage. If you have an efficient modulator, you can do away with linear amplifiers (which is why it was in that SSB book). I gather he used the scheme in at least one of the amateur satellites after Oscar 6. But what happens in the digital age? Can you generate the two streems, in essence but not so simple an FM component and an AM component, without needing to generate SSB and then extract the two streams? I don't know, but so much digital processing is being done now, it may be something to look into. With solid state devices and class D amplifiers, modulating high level class C amplifiers can't be as much trouble as in the old days. Maybe it amounts to nothing, but maybe it overall becomes more efficient, if it can be done. Maybe there's no value to digital voice, except that in the process of learnign about it, and implementing it, one can learn something. Maybe something merely new to the person learning, but maybe something completely new. No advances are made without learning, the learning triggers new advances. Michael You do realise that you're responding to a troll post, right? Only because you continue to keep that war going even as it spills out of the UK newsgroup. I didnt' "feed the troll", you do that all the time by keeping up the vendetta. I chose to say something about the topic, certainly about how ideas advance, and it exists whether or not he is a troll. Michael |
What is the point of digital voice?
"robert bristow-johnson" wrote in message ... On 2/25/15 12:46 PM, Jim GM4DHJ ... wrote: As I said, as I had some difficulties which were resolved, that places me in a good position to assist others who may also have such difficulties. don't worry about it...teechers don't do nuffin wurfwhile at skool .... yoos to b i cudn't even spel injunear, now i arr won. -- r b-j "Imagination is more important than knowledge." fenestrating..... |
What is the point of digital voice?
"Stephen Thomas Cole" wrote in message
... It all sprang from Gareth being corrected over one of his routine total misunderstandings and he went off the deep end about it, as per, and cooked up "Big K", a Time Cube like confabulation and misrepresentation of known physics. Some time later, after receiving much mocking, he declared that he'd found some obscure textbook (AIUI, nobody has been able to verify the contents of this supposed textbook, or even its existence) that proved that he was correct and that every other person on the planet was wrong and always had been. Thereafter, he refused to be drawn further on "Big K", saying that he had settled the matter "to [his] satisfaction". But ... if EVERYONE else was wrong that included the author of the booK he was quoting from. Time for a drinK -- ;-) .. 73 de Frank Turner-Smith G3VKI - mine's a pint. .. http://turner-smith.co.uk |
What is the point of digital voice?
"Michael Black" wrote in message
news:alpine.LNX.2.02.1502251356170.14915@darkstar. example.org... Only because you continue to keep that war going even as it spills out of the UK newsgroup. I didnt' "feed the troll", you do that all the time by keeping up the vendetta. I chose to say something about the topic, certainly about how ideas advance, and it exists whether or not he is a troll. I am no troll, but a spokesman for the technical and gentlemanly traditions of amateur radio, but Cole, having no experience of either, resorts to childish tirades of abuse in a vain attempt to mask his appalling ignorance. It has been very ntoiceable today that Cole's posts have all been vehicles for gratuitous abuse. |
What is the point of digital voice?
En el artículo , Stephen Thomas Cole
escribió: You caused so much damage to their reputation they had to rebrand? By Jove! Gareth "Poison Ivy" Evans strikes again! -- :: je suis Charlie :: yo soy Charlie :: ik ben Charlie :: |
What is the point of digital voice?
"Mike Tomlinson" wrote in message
... En el artículo , Stephen Thomas Cole escribió: You caused so much damage to their reputation they had to rebrand? By Jove! Gareth "Poison Ivy" Evans strikes again! You continue with your one-sided assaults occasioned by your infantile fixation. |
What is the point of digital voice?
On 2/25/2015 6:05 AM, Roger Hayter wrote:
Jerry Stuckle wrote: On 2/24/2015 7:03 PM, rickman wrote: On 2/24/2015 6:37 PM, Jerry Stuckle wrote: On 2/24/2015 5:47 PM, rickman wrote: On 2/24/2015 12:00 PM, Jerry Stuckle wrote: On 2/24/2015 11:32 AM, FranK Turner-Smith G3VKI wrote: "AndyW" wrote in message ... On 24/02/2015 12:47, gareth wrote: What is the point of digital voice when there are already AM, SSB and FM for those who want to appear indistinguishable from CBers? Perhaps it is cynicism from the manufacturers who introduce such things as they see their traditional highly-priced corner of the market being wiped away by SDR technologies? Bandwidth reduction for one. If you can encode and compress speech sufficiently then you can use less bandwidth in transmission. That's the bit I have trouble getting my head around. Back in the 1970s and 1980s digital transmissions used a much greater bandwidth than their analogue equivalents. Sampling at 2.2 x max frequency x number of bits plus housekeeping bits etc. etc. A UK standard 625 line PAL video transmission would have used a bandwidth of over 400MHz! Times have changed and left me behind, but I've still got me beer so who cares? But you forget compression. For instance, unless there is a scene change, the vast majority of a television picture does not change from frame to frame. Even if the camera moves, the picture shifts but doesn't change all that much. Why waste all of that bandwidth resending information the receiver already has? And voice isn't continuous; it has lots of pauses. Some are very noticeable, while others are so short we don't consciously hear them, but they are there. And once you've compressed everything you can out of the original signal, you can do bit compression, similar to zipping a file for sending. There are lots of ways to compress a signal before sending it digitally. About the only one which can't be compressed is pure white noise - which, of course, is only a concept (nothing is "pure"). I think that depends on what you mean by "pure". Sounds very non-technical to me. Even noise can be compressed since if it is truly noise, you don't need to send the data, just send the one bit that says there is no signal, just noise. lol Pure white noise is a random distribution of signal across the entire spectrum, with an equal distribution of frequencies over time. Like a pure resistor or capacitor, it doesn't exist. But the noise IS the signal. To recreate the noise, you have to sample the signal and transmit it. However, since it is completely random, by definition no compression is possible. Why does it not "exist"? That is not at all clear. You don't understand compression. Compression is a means of removing the part of a signal that is unimportant and sending only the part that is important. In most cases of "pure" noise, you can just send a statement that the signal is "noise" without caring about the exact voltages over time. So, yes, even noise can be compressed depending on your requirements. Pure white noise is a concept only. There is no perfect white noise source, just as there is no pure resistor or capacitor. And yes, I do understand compression. One of the things it depends on is predictability and repeatability of the incoming signal. That does not exist with white noise. The fact you don't understand that pure white noise is only a concept and cannot exist in the real world shows your lack of understanding. Some compression algorithms (i.e. mp3) remove what they consider is "unimportant". However, the result after decompressing is a poor recreation of the original signal. But for perfect recreation, nothing is "unimportant". Voice/video compression is no different than file compression on a computer. Can you imaging what would happen if your favorite program was not perfectly recreated? A friend worked in sonar where the data was collected on ships and transmitted via satellite to shore for signal processing rather than doing any compression on the data and sending the useful info. As the signal was nearly all "noise" trying to do any compression on it, even the aspects that weren't "pure" white noise, would potentially have masked the signals. Sonar is all about pulling the signal out of the noise. You mean the signal can't be compressed? No way. Any non-random signal can be compressed to some extent. How much depends on the signal and the amount of processing power required to compress it. However, in your example, the processing power to compress the signal would probably have been greater than that required to process the original signal. So if there wasn't enough power to process the signal on the ship, there wouldn't be enough power to compress the near-white noise signal, either. You really like your all encompassing assumptions. No, all signals can not be compressed, even non-noise signals can't be compressed if the signal is not appropriate for the compressor. This is really a very large topic and I think you are used to dealing with the special cases without understanding the general case. Which is just the opposite of what you claimed above. Please make up your mind. Try visiting comp.compression and offering them your opinions. There are many there who are happy to explain the details to you. I understand the details, thank you. Much better than you do, obviously. But that's not surprising, either. You are both talking at cross-purposes. One of you is talking of taking a sample of white noise and storing it as data. Because of its statistical properties I would not be surprised if it were impossible to compress. The other is assuming that by definition noise is not data and compression would only be usefully applied to a hypothetical signal added to the white noise, when no properties of the noise would be relevant for the compressed signal. I can't think why one should want to record and store a sample of white noise, but that does not prevent it being used as a hypothetical example. I doubt you really have any disagreement, just a misunderstanding. No, it is a fundamental issue in compression theory. *Any* signal can be compressed if you use the right compressor. Likewise there is *no* compressor that will compress every signal. They call this the counting theorem. Using N bits you can represent 2^N possible signals. Compression by definition uses a smaller number of bits, say M, to represent the data. There will only be *some* of the possible input combinations from the N set that can be represented by the M set. The remaining combinations (2^N - 2^M) will require *more* bits to represent them. Conventional compression algorithms take advantage of redundancy in the input signal to represent them with fewer bits, usually a lot fewer bits. But by the same token there are the 2^N - 2^M possible signals that these compressors will not compress and will either not reproduce the input exactly or will require extra bits. There was nothing in the above that says anything about which bit patterns can be compressed or not compressed. Some people get confused about the fact that most compression algorithms work on removing redundancy and think that is the only way to compress a signal. When discussing the theoretical we need to distinguish the things that are possible from the things that are useful. Then there is the side discussion of what white noise is and if it is a concept or possible. A rather pointless discussion in the context of compression, but there it is. -- Rick |
What is the point of digital voice?
On 2/25/2015 12:09 PM, UK Support wrote:
"gareth" wrote: "rickman" wrote in message ... Maybe I don't understand the issue. Isn't that a valid example of a negative frequency? There are some DSP experts in comp.dsp who talk about negative frequency often. If you, or, indeed, anyone else has any difficulties with the subject matter and DSP in general, then do ask me, because having worked through what appeared as a number of anomalies (all resolved 9 years ago when I was working as a DSP manufacturer, picoChip in Bath, UK) I feel sure that I'm well positioned to understand the difficulties that others might encounter in this area. No. Don't. Trust me on this. He said he can understand the difficulties that others might encounter, not the solutions. -- Rick |
What is the point of digital voice?
On 2/25/2015 6:02 AM, gareth wrote:
"Brian Reay" wrote in message ... He is (deliberately) misrepresenting the discussion. The point was made that the phasor was rotating clockwise, thus the angle decreasing, ie becoming negative. Untrue, no mention of the angle, as below ... -----ooooo----- From: "Brian Reay" Newsgroups: alt.engineering.electrical,uk.radio.amateur Subject: Phase noise Date: Sat, 13 Dec 2003 10:21:54 -0000 Message-ID: Equally, it is easy to mis-interpret the maths as Gareth has done in: cos(wt) = 1/2 * ( e^(jwt) +e^(-jwt) ) The term e^(-jwt) isn't some magical time machine relating to "minus time", e^(-jwt) is simply another way of writing 1/(e^jwt) which is a value that decreases as t increasing. I see what you guys mean. He doesn't even understand what e^jwt is. He sees it as no different from e^wt. -- Rick |
What is the point of digital voice?
On 2/25/2015 4:43 AM, Brian Reay wrote:
On 25/02/15 08:53, Stephen Thomas Cole wrote: rickman wrote: Perhaps you can explain this with a little math? Sadly, Gareth absolutely cannot explain it. He doesn't remotely understand anything he's talking about, as per. That is a major part of his problem. He just isn't up to the level of technical stuff he aspires to, in fact he has glaring gaps in even the basics. I don't see that as a fault. I often tackle difficult issues I don't understand in the hope of learning more. Rather than try and learn, he tries to bluff that he knows far more than he does. When he is shown to be a charlatan, he turns to abuse. Even that is predictable in the path it will take, including his most extreme steps. Yeah, well, that isn't so good. But it is interesting that so many are so happy to pile on and give the guy grief. As you say, he is best ignored, although some of his whacky theories have given me a good laugh from time to time. It's good to eat your vegetables too, but how many actually do it? -- Rick |
What is the point of digital voice?
On 2/25/2015 5:39 AM, gareth wrote:
"rickman" wrote in message ... I thought it might be that, but it still makes no sense to me. Who or how does changing the direction of rotation of a rotating vector change its "size". Are you defining size as the rotation so that going from a + to a - is like reversing the direction of a vector? I think most people would consider the "size" of a vector to be the magnitude which is independent of phase angle and so rotation, no? Perhaps you can explain this with a little math? Not my gibberish, refer to the original posting ... -----ooooo----- From: "Brian Reay" Newsgroups: alt.engineering.electrical,uk.radio.amateur Subject: Phase noise Date: Sat, 13 Dec 2003 10:21:54 -0000 Message-ID: The term e^(-jwt) isn't some magical time machine relating to "minus time", e^(-jwt) is simply another way of writing 1/(e^jwt) which is a value that decreases as t increasing. Yeah, well this is not really correct unless I misunderstand what you mean by "decreases". When the j factor is included in the exponent of e, the function changes dramatically so that it does *not* exponentially decrease in magnitude as t increases. -- Rick |
I think that the problem here is that a good question was asked and it has been turned into a ****ing match.
Its not about who is smarter then who, but answering the question in a fashionable manner. Here is an observation that I am going to make and maybe some forum members can comment in a positive manner. For the first 70 years of radio, it has been the amateurs that has come up with the new technology. This technology was then transferred to the commercial side of radio. Even the slow scan television that was used by NASA when they landed on the moon. Today the technology is developed for public service radio and then it is converted to be used by amateur radio - after it is perfected by field testing it on the amateur radio frequencies.. You see - the problem is that there isn't any bandwidth left on the public service frequencies and so anything that they implement has to work before they deploy it. It has nothing to do with using the frequencies that we have been given - more efficiently. Heck we have whole segments of bandwidth that isn't even used in most area's of the country. Our biggest problem is that we use these frequencies for free, while other entities such as cellular telephone is willing to pay for that bandwidth. Eventually what is going to happen is that it is going to be taken away from the amateurs, which is the reason why we left the barn door open and left the morons into amateur radio so we could swell our ranks so we could justify keeping the bandwidth given to us. Talk around the FCC is that the FCC has received proposals to revoke privileges on the HF bands to operate AM Phone. Most of the amateurs that uses digital is screaming for a larger portion of the spectrum to be set aside for digital only and to keep CW and phone away from their frequencies. As the rule is now written, you can operate CW anywhere on most any HF band. The only way to give the digital people the bandwidth that they require is to take bandwidth away from others such as phone operators. The only place they can take it from would be the amateur extra portion of the bands. There has also been petitions filed to allow amateurs with just a technician class license to operate digital modes on more bands then just 10 meters and up. The FCC's response has been if they want to work digital that they need to upgrade their license. This is how the incentive license program works. Our problem is that the people that are lowly technicians are just technicians because they are either too stupid to pass another 35 question test or they are too lazy to take the test to get a General Class License... |
What is the point of digital voice?
"FranK Turner-Smith G3VKI" wrote:
"Stephen Thomas Cole" wrote in message ... It all sprang from Gareth being corrected over one of his routine total misunderstandings and he went off the deep end about it, as per, and cooked up "Big K", a Time Cube like confabulation and misrepresentation of known physics. Some time later, after receiving much mocking, he declared that he'd found some obscure textbook (AIUI, nobody has been able to verify the contents of this supposed textbook, or even its existence) that proved that he was correct and that every other person on the planet was wrong and always had been. Thereafter, he refused to be drawn further on "Big K", saying that he had settled the matter "to [his] satisfaction". But ... if EVERYONE else was wrong that included the author of the booK he was quoting from. Time for a drinK Paradoxes abound in Gareth's world. -- STC // M0TEY // twitter.com/ukradioamateur |
What is the point of digital voice?
Michael Black wrote:
On Wed, 25 Feb 2015, Stephen Thomas Cole wrote: Michael Black wrote: On Tue, 24 Feb 2015, gareth wrote: What is the point of digital voice when there are already AM, SSB and FM for those who want to appear indistinguishable from CBers? Perhaps it is cynicism from the manufacturers who introduce such things as they see their traditional highly-priced corner of the market being wiped away by SDR technologies? Because it's something new, at least to amateur radio. The phasing method of sideband was common in the early days of amateur SSB (I recall reading the first rigs were filter type, but with really low IFs, then phasing, then crystal and mechanical filters took over from phasing). It offered up a lot on transmit and receive, though not perfection. But now phasing is used a lot, because digital circuitry has made it viable. I remember seeing some of the potential when phasing was still analog, but I also remember reading articles where it was clear others didn't see the potential. Sometimes ideas become lost when something becomes commonplace. Who knows what would come from digital voice. But I remember 30 years ago one local ham being interested in it, not to the extent of putting something on the air, but as information from the computer world started flowing in, the potential started being there. YOu can't resist new things and say "they have no use", you have to embrace the new and see what can be done with it. Maybe not as initially seen, but maybe it fits in somewhere else. Amateur radio has never done much with envelope elimination and restoration (was that what it was called? I now forget). It's in one of the sideband books, and Karl Meinzer of AMSAT fame wrote about it in QST about 1970. Break the SSB signal into two components, so you can multiply it up to a higher frequency, then modulate the output stage. If you have an efficient modulator, you can do away with linear amplifiers (which is why it was in that SSB book). I gather he used the scheme in at least one of the amateur satellites after Oscar 6. But what happens in the digital age? Can you generate the two streems, in essence but not so simple an FM component and an AM component, without needing to generate SSB and then extract the two streams? I don't know, but so much digital processing is being done now, it may be something to look into. With solid state devices and class D amplifiers, modulating high level class C amplifiers can't be as much trouble as in the old days. Maybe it amounts to nothing, but maybe it overall becomes more efficient, if it can be done. Maybe there's no value to digital voice, except that in the process of learnign about it, and implementing it, one can learn something. Maybe something merely new to the person learning, but maybe something completely new. No advances are made without learning, the learning triggers new advances. Michael You do realise that you're responding to a troll post, right? Only because you continue to keep that war going even as it spills out of the UK newsgroup. I didnt' "feed the troll", you do that all the time by keeping up the vendetta. I chose to say something about the topic, certainly about how ideas advance, and it exists whether or not he is a troll. Michael Sadly, Michael, your efforts were wasted on Gareth. He wouldn't have understood a single word you said. -- STC // M0TEY // twitter.com/ukradioamateur |
What is the point of digital voice?
On Wed, 25 Feb 2015 14:56:42 -0500, rickman wrote:
I see what you guys mean. He doesn't even understand what e^jwt is. He sees it as no different from e^wt. He's a polyidiot - there really is no boundary to his idiocy. |
What is the point of digital voice?
"rickman" wrote in message
... On 2/25/2015 4:43 AM, Brian Reay wrote: Rather than try and learn, he tries to bluff that he knows far more than he does. When he is shown to be a charlatan, he turns to abuse. Even that is predictable in the path it will take, including his most extreme steps. Yeah, well, that isn't so good. But it is interesting that so many are so happy to pile on and give the guy grief. The reason that it isn't so good is that it is untrue. |
What is the point of digital voice?
"rickman" wrote in message
... On 2/25/2015 5:39 AM, gareth wrote: "rickman" wrote in message ... I thought it might be that, but it still makes no sense to me. Who or how does changing the direction of rotation of a rotating vector change its "size". Are you defining size as the rotation so that going from a + to a - is like reversing the direction of a vector? I think most people would consider the "size" of a vector to be the magnitude which is independent of phase angle and so rotation, no? Perhaps you can explain this with a little math? Not my gibberish, refer to the original posting ... -----ooooo----- From: "Brian Reay" Newsgroups: alt.engineering.electrical,uk.radio.amateur Subject: Phase noise Date: Sat, 13 Dec 2003 10:21:54 -0000 Message-ID: The term e^(-jwt) isn't some magical time machine relating to "minus time", e^(-jwt) is simply another way of writing 1/(e^jwt) which is a value that decreases as t increasing. Yeah, well this is not really correct unless I misunderstand what you mean by "decreases". When the j factor is included in the exponent of e, the function changes dramatically so that it does *not* exponentially decrease in magnitude as t increases. WHS |
What is the point of digital voice?
"Stephen Thomas Cole" wrote in message
... Sadly, Michael, your efforts were wasted on Gareth. He wouldn't have understood a single word you said. You continue to post messages which are nothing but abuse. |
| All times are GMT +1. The time now is 11:40 PM. |
Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
RadioBanter.com