"Jon Harris" <goldentully@hotmail.com> wrote in message news:2h46a1F8tjkvU1@uni-berlin.de...> "Richard Crowley" <rcrowley7@xprt.net> wrote in message > news:10aola6pnbau090@corp.supernews.com... > > > > Of course true "1-bit" audio is indistinguishable from > > random noise. > > Not really. DSD is one bit (at a very high sampling rate) and certainlydoesn't> sound like random noise. Even with "regular" sample rates such as44.1kHz, so> you can still recognize properly-dithered audio at very low bit depths(even 1> bit). The audio is buried in noise, just like it would sound if yourecorded at> very low levels on a medium such as cassette tape, but the ear is prettygood at> pulling out the real sound from the noise.While theoretically possible, this seems light-years away from the OP's original discussion, hence my "shocking" statement.
1-Bit Wave File?
Started by ●May 16, 2004
Reply by ●May 21, 20042004-05-21
Reply by ●May 21, 20042004-05-21
Paavo Jumppanen wrote:> Me <secad@netspace.net.au> wrote in message news:<c8i3fp$1kpk$1@otis.netspace.net.au>... > >>Curious wrote: >> >> >>>I am looking for audio software that allows conversion of 16-bit WAVs >>>and 8-bit WAVs to 1-bit WAVs. I have used Adobe Audition and CakeWalk >>>Pyro. Neither of them work. CakeWalk does have a "bit-depth converter" >>>as a FX, however, when I try to use it, I get a runtime error and >>>Cakewalk automatically closes. >> >> A + Comparator FlipFlop >>I/P -------|\ +------+ Q >> | >----------| D Q|---+---- Bitstream out >> B +--|/ C +--|> | | >> | - | +------+ | >> | | | >> +-/\/\/\-----)-------------+ >> | R | >> C === | >> | Fs---+ >> 0V >> >>Several years ago I made a delay line to delay the audio for a walkie-talkie >>so that the Tx VOX voice operated switch and Rx unmute operation would be >>completed before the leading word spoken by the operator was transmitted. >>I tried a bucket brigade device (MN3001) but had troubles with noise and >>limitations on maximum delay. >> >>I tried the cct above as a 1-bit encoder (mentioned in a mag somewhere), >>clocked at over 200KHz. I do not know if the cct has a name. >> > > > The above circuit looks to me very much like an implementation of a > delta modulator, the RC circuit being a lossy integrator. This is the > forunner to delta-sigma isn't it? > > Paavo Jumppanen > Author of HarBal Harmonic Balancer > http://www.har-bal.comIt looks to me as if the comparator will oscillate at a variable frequency and a duty cycle such that the average DC in its output is the same as the level at its input. The flip-flop merely quantizes the transition times. It's effectively a Class D amplifier. Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
Reply by ●May 21, 20042004-05-21
"Jerry Avins" <jya@ieee.org> wrote in message news:40ad4ecf$0$3106$61fed72c@news.rcn.com...> Dick Pierce wrote: > > "Richard Crowley" <rcrowley7@xprt.net> wrote in messagenews:<10aola6pnbau090@corp.supernews.com>...> >>Of course true "1-bit" audio is indistinguishable from > >>random noise. > > In a word, wrong. In two words, completely wrong. > > A 1-bit stream is perfectly capable of holding quite intelligible > > audio. It will have a broadband dynamic range of only 6 dB, but > > that is quite enough for intelligible speech and easily recognizable > > music.> Please read the thread and don't try to justify balf-baked ideas.Nothing half baked about Dicks ideas!> > You should maybe review works such as Lipshitz and Vanderkooy's > > "Resolution below the least significant bit in audio systems with > > dither" from JAES before making such a pronouncement.> Why? It's irrelevant to this thread.Dick specifically responded to Richards incorrect statement. Your post is irrelevant to that. TonyP.
Reply by ●May 21, 20042004-05-21
"TonyP" <TonyP@optus.net.com.au> wrote in message news:40adc228$0$1584$afc38c87@news.optusnet.com.au...> > "Jerry Avins" <jya@ieee.org> wrote in message > news:40ad4ecf$0$3106$61fed72c@news.rcn.com... > > Dick Pierce wrote: > > > "Richard Crowley" <rcrowley7@xprt.net> wrote in message > news:<10aola6pnbau090@corp.supernews.com>... > > >>Of course true "1-bit" audio is indistinguishable from > > >>random noise. > > > In a word, wrong. In two words, completely wrong. > > > A 1-bit stream is perfectly capable of holding quite intelligible > > > audio. It will have a broadband dynamic range of only 6 dB, but > > > that is quite enough for intelligible speech and easily recognizable > > > music. > > > Please read the thread and don't try to justify balf-baked ideas. > > Nothing half baked about Dicks ideas! > > > > You should maybe review works such as Lipshitz and Vanderkooy's > > > "Resolution below the least significant bit in audio systems with > > > dither" from JAES before making such a pronouncement. > > > Why? It's irrelevant to this thread. > > Dick specifically responded to Richards incorrect statement. Your post is > irrelevant to that.My statement was not incorrect. If you go back and read the OP's theory, he wanted to reduce NORMAL SAMPLING RATE (i.e. 44-48K) streams to very low (i.e. 1) bit depth. I still maintain that a 44 or 48K by 1-bit stream is virtually indistinguishable from noise. Most certainly, if you greatly increase the sampling rate (as any 1-bit D/A converter does) you restore "fidelity". But this was NOT the OPs theory. One of the characeristics of Usenet it the great tendency to go off and discuss semi-related theory even when it has no impact on the original question. On one side, this is a benefit for those lurking to learn some bits of theory. OTOH, it leads some to completely falacious associations between uncorrelated theory and the original issue.
Reply by ●May 21, 20042004-05-21
"Richard Crowley" <rcrowley7@xprt.net> writes:> "TonyP" <TonyP@optus.net.com.au> wrote in message > news:40adc228$0$1584$afc38c87@news.optusnet.com.au... >> >> "Jerry Avins" <jya@ieee.org> wrote in message >> news:40ad4ecf$0$3106$61fed72c@news.rcn.com... >> > Dick Pierce wrote: >> > > "Richard Crowley" <rcrowley7@xprt.net> wrote in message >> news:<10aola6pnbau090@corp.supernews.com>... >> > >>Of course true "1-bit" audio is indistinguishable from >> > >>random noise. >> > > In a word, wrong. In two words, completely wrong. >> > > A 1-bit stream is perfectly capable of holding quite intelligible >> > > audio. It will have a broadband dynamic range of only 6 dB, but >> > > that is quite enough for intelligible speech and easily recognizable >> > > music. >> >> > Please read the thread and don't try to justify balf-baked ideas. >> >> Nothing half baked about Dicks ideas! >> >> > > You should maybe review works such as Lipshitz and Vanderkooy's >> > > "Resolution below the least significant bit in audio systems with >> > > dither" from JAES before making such a pronouncement. >> >> > Why? It's irrelevant to this thread. >> >> Dick specifically responded to Richards incorrect statement. Your post is >> irrelevant to that. > > My statement was not incorrect. If you go back and read > the OP's theory, he wanted to reduce NORMAL SAMPLING > RATE (i.e. 44-48K) streams to very low (i.e. 1) bit depth. > > I still maintain that a 44 or 48K by 1-bit stream is virtually > indistinguishable from noise.Without entering into the debate about Dick's response, let me say, Richard, that I think even a 1-bit, 44.1 kHz signal will not be PURELY noise-like. The noise will be high, but my intuition tells me you will be able to hear the signal (at least one that is at a high level) in the noise. Almost certainly one would be able to hear a full-scale sinewave in such noise. -- % Randy Yates % "My Shangri-la has gone away, fading like %% Fuquay-Varina, NC % the Beatles on 'Hey Jude'" %%% 919-577-9882 % %%%% <yates@ieee.org> % 'Shangri-La', *A New World Record*, ELO http://home.earthlink.net/~yatescr
Reply by ●May 21, 20042004-05-21
Randy Yates wrote:> > Without entering into the debate about Dick's response, let me say, Richard, > that I think even a 1-bit, 44.1 kHz signal will not be PURELY noise-like.It's been about 15 years ago but I once played around with something like this. Don't remember all the exact details. But, start with a good quality speech recording sampled at somewhere in the 10-20KHz range 8-bit signed integers (or maybe it was 16 bit). Then filter out most of the low frequency content - I think at this point most of the frequency content was in the 1-4KHz range (sounds very tinny but still understandable)), then quantized down to one bit (set all but sign bit to zero) then apply a low pass filter to smooth out the square waves. On playback the result was surprisingly good - well at least as good as early sound recordings. It worked quite well for speech but music sounded very strange.> The noise will be high, but my intuition tells me you will be able to hear > the signal (at least one that is at a high level) in the noise. Almost > certainly one would be able to hear a full-scale sinewave in such noise.Why would the scale of the sine wave make any difference or maybe I misunderstand what you're saying. -jim -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =-----
Reply by ●May 21, 20042004-05-21
TonyP wrote:> "Jerry Avins" <jya@ieee.org> wrote in message > news:40ad4ecf$0$3106$61fed72c@news.rcn.com... > >>Dick Pierce wrote: >> >>>"Richard Crowley" <rcrowley7@xprt.net> wrote in message > > news:<10aola6pnbau090@corp.supernews.com>... > >>>>Of course true "1-bit" audio is indistinguishable from >>>>random noise. >>> >>>In a word, wrong. In two words, completely wrong. >>>A 1-bit stream is perfectly capable of holding quite intelligible >>>audio. It will have a broadband dynamic range of only 6 dB, but >>>that is quite enough for intelligible speech and easily recognizable >>>music. > > >>Please read the thread and don't try to justify balf-baked ideas. > > > Nothing half baked about Dicks ideas!As far as facts go, Dick is right on the mark. Nothing half baked there. The notion of making sound with just the sign bit of a sampled waveform and expecting it to sound like an old movie sound track: that's half baked.>>>You should maybe review works such as Lipshitz and Vanderkooy's >>>"Resolution below the least significant bit in audio systems with >>>dither" from JAES before making such a pronouncement. > > >>Why? It's irrelevant to this thread. > > > Dick specifically responded to Richards incorrect statement. Your post is > irrelevant to that.He responded with IMHO irrelevant examples useful of 1-bit signals. (He could have added delta modulation and bit-serial data protocols.)> TonyP. > >Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
Reply by ●May 21, 20042004-05-21
Richard Crowley wrote: ...> My statement was not incorrect. If you go back and read > the OP's theory, he wanted to reduce NORMAL SAMPLING > RATE (i.e. 44-48K) streams to very low (i.e. 1) bit depth. > > I still maintain that a 44 or 48K by 1-bit stream is virtually > indistinguishable from noise. Most certainly, if you greatly > increase the sampling rate (as any 1-bit D/A converter does) > you restore "fidelity". But this was NOT the OPs theory.Reducing the bit depth to one is the same as extracting the sign bit, which in turn is the same as clipping with very high gain. One can hear what this sounds like by running an audio signal into a comparator with bi-polar output. (Make one from an op-amp.) It isn't pretty; you can hear some beat, but no recognizable tune. Cacophony? Yes. Noise? Well... no.> One of the characeristics of Usenet it the great tendency to go > off and discuss semi-related theory even when it has no impact > on the original question. On one side, this is a benefit for those > lurking to learn some bits of theory. OTOH, it leads some to > completely falacious associations between uncorrelated theory > and the original issue.Right on. You said what I meant. Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
Reply by ●May 21, 20042004-05-21
Jerry Avins <jya@ieee.org> writes:> Richard Crowley wrote: > > ... > > > > My statement was not incorrect. If you go back and read > > the OP's theory, he wanted to reduce NORMAL SAMPLING > > RATE (i.e. 44-48K) streams to very low (i.e. 1) bit depth. > > I still maintain that a 44 or 48K by 1-bit stream is virtually > > > indistinguishable from noise. Most certainly, if you greatly > > increase the sampling rate (as any 1-bit D/A converter does) > > you restore "fidelity". But this was NOT the OPs theory. > > Reducing the bit depth to one is the same as extracting the sign bit, > which in turn is the same as clipping with very high gain. One can > hear what this sounds like by running an audio signal into a > comparator with bi-polar output. (Make one from an op-amp.) It isn't > pretty; you can hear some beat, but no recognizable tune. Cacophony? > Yes. Noise? Well... no.I was presuming the appropriate amount of dither was used in the requantization. Otherwise it would be much much worse sounding, and, I agree, non-noise-like. -- Randy Yates Sony Ericsson Mobile Communications Research Triangle Park, NC, USA randy.yates@sonyericsson.com, 919-472-1124
Reply by ●May 21, 20042004-05-21
Richard Crowley <rcrowley7@xprt.net> wrote:> I still maintain that a 44 or 48K by 1-bit stream is virtually > indistinguishable from noise.Have you actually tried it? I have (in Matlab) and it's actually quite surprising just how intelligible the result still is (not that you'd mistake it for 'hi fi' in your lifetime...). ---Joel Kolstad
