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#81
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1-Bit Wave File?
"Richard Crowley" wrote in message
... Of course true "1-bit" audio is indistinguishable from random noise. Not really. DSD is one bit (at a very high sampling rate) and certainly doesn't sound like random noise. Even with "regular" sample rates such as 44.1kHz, 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 you recorded at very low levels on a medium such as cassette tape, but the ear is pretty good at pulling out the real sound from the noise. |
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#82
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1-Bit Wave File?
Randy Yates wrote:
Bit-depth reducing to 1 bit does not convert PCM into a PWM signal. On the other hand, I guess it does, Absolutely it does not. A PWM signal has the property that at time n*T the signal begins at a high state for p*T seconds and ends at a low state for (1-p)*T seconds, 0 = p = 1. A 1-bit bitstream does not have this property. Many people seem to have this misconception that a delta sigma bitstream is a PWM waveform. It is not - they are two different animals. I was alluding to the resultant signal being an asymetrical bitstream, like a PWM signal. Though I did qualify that it bears no relationship to any encoded signal. One "1", followed by one "0", then two "1"s followed by a "0" looks PWM to me. geoff |
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#83
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1-Bit Wave File?
Randy Yates wrote:
Bit-depth reducing to 1 bit does not convert PCM into a PWM signal. On the other hand, I guess it does, Absolutely it does not. A PWM signal has the property that at time n*T the signal begins at a high state for p*T seconds and ends at a low state for (1-p)*T seconds, 0 = p = 1. A 1-bit bitstream does not have this property. Many people seem to have this misconception that a delta sigma bitstream is a PWM waveform. It is not - they are two different animals. I was alluding to the resultant signal being an asymetrical bitstream, like a PWM signal. Though I did qualify that it bears no relationship to any encoded signal. One "1", followed by one "0", then two "1"s followed by a "0" looks PWM to me. geoff |
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#84
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1-Bit Wave File?
Randy Yates wrote:
Bit-depth reducing to 1 bit does not convert PCM into a PWM signal. On the other hand, I guess it does, Absolutely it does not. A PWM signal has the property that at time n*T the signal begins at a high state for p*T seconds and ends at a low state for (1-p)*T seconds, 0 = p = 1. A 1-bit bitstream does not have this property. Many people seem to have this misconception that a delta sigma bitstream is a PWM waveform. It is not - they are two different animals. I was alluding to the resultant signal being an asymetrical bitstream, like a PWM signal. Though I did qualify that it bears no relationship to any encoded signal. One "1", followed by one "0", then two "1"s followed by a "0" looks PWM to me. geoff |
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#85
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1-Bit Wave File?
Randy Yates wrote:
Bit-depth reducing to 1 bit does not convert PCM into a PWM signal. On the other hand, I guess it does, Absolutely it does not. A PWM signal has the property that at time n*T the signal begins at a high state for p*T seconds and ends at a low state for (1-p)*T seconds, 0 = p = 1. A 1-bit bitstream does not have this property. Many people seem to have this misconception that a delta sigma bitstream is a PWM waveform. It is not - they are two different animals. I was alluding to the resultant signal being an asymetrical bitstream, like a PWM signal. Though I did qualify that it bears no relationship to any encoded signal. One "1", followed by one "0", then two "1"s followed by a "0" looks PWM to me. geoff |
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#86
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1-Bit Wave File?
"Geoff Wood" -nospam writes:
Randy Yates wrote: Bit-depth reducing to 1 bit does not convert PCM into a PWM signal. On the other hand, I guess it does, Absolutely it does not. A PWM signal has the property that at time n*T the signal begins at a high state for p*T seconds and ends at a low state for (1-p)*T seconds, 0 = p = 1. A 1-bit bitstream does not have this property. Many people seem to have this misconception that a delta sigma bitstream is a PWM waveform. It is not - they are two different animals. I was alluding to the resultant signal being an asymetrical bitstream, like a PWM signal. I have no idea what you mean. Though I did qualify that it bears no relationship to any encoded signal. What is "it"? One "1", followed by one "0", then two "1"s followed by a "0" looks PWM to me. How so? It doesn't match any definition of PWM that I know of. When I talk about PWM, I mean, e.g., the type of signal shown in figure one of http://www.embedded.com/story/OEG20010821S0096 -- Randy Yates Sony Ericsson Mobile Communications Research Triangle Park, NC, USA , 919-472-1124 |
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#87
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1-Bit Wave File?
"Geoff Wood" -nospam writes:
Randy Yates wrote: Bit-depth reducing to 1 bit does not convert PCM into a PWM signal. On the other hand, I guess it does, Absolutely it does not. A PWM signal has the property that at time n*T the signal begins at a high state for p*T seconds and ends at a low state for (1-p)*T seconds, 0 = p = 1. A 1-bit bitstream does not have this property. Many people seem to have this misconception that a delta sigma bitstream is a PWM waveform. It is not - they are two different animals. I was alluding to the resultant signal being an asymetrical bitstream, like a PWM signal. I have no idea what you mean. Though I did qualify that it bears no relationship to any encoded signal. What is "it"? One "1", followed by one "0", then two "1"s followed by a "0" looks PWM to me. How so? It doesn't match any definition of PWM that I know of. When I talk about PWM, I mean, e.g., the type of signal shown in figure one of http://www.embedded.com/story/OEG20010821S0096 -- Randy Yates Sony Ericsson Mobile Communications Research Triangle Park, NC, USA , 919-472-1124 |
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#88
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1-Bit Wave File?
"Geoff Wood" -nospam writes:
Randy Yates wrote: Bit-depth reducing to 1 bit does not convert PCM into a PWM signal. On the other hand, I guess it does, Absolutely it does not. A PWM signal has the property that at time n*T the signal begins at a high state for p*T seconds and ends at a low state for (1-p)*T seconds, 0 = p = 1. A 1-bit bitstream does not have this property. Many people seem to have this misconception that a delta sigma bitstream is a PWM waveform. It is not - they are two different animals. I was alluding to the resultant signal being an asymetrical bitstream, like a PWM signal. I have no idea what you mean. Though I did qualify that it bears no relationship to any encoded signal. What is "it"? One "1", followed by one "0", then two "1"s followed by a "0" looks PWM to me. How so? It doesn't match any definition of PWM that I know of. When I talk about PWM, I mean, e.g., the type of signal shown in figure one of http://www.embedded.com/story/OEG20010821S0096 -- Randy Yates Sony Ericsson Mobile Communications Research Triangle Park, NC, USA , 919-472-1124 |
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#89
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1-Bit Wave File?
"Geoff Wood" -nospam writes:
Randy Yates wrote: Bit-depth reducing to 1 bit does not convert PCM into a PWM signal. On the other hand, I guess it does, Absolutely it does not. A PWM signal has the property that at time n*T the signal begins at a high state for p*T seconds and ends at a low state for (1-p)*T seconds, 0 = p = 1. A 1-bit bitstream does not have this property. Many people seem to have this misconception that a delta sigma bitstream is a PWM waveform. It is not - they are two different animals. I was alluding to the resultant signal being an asymetrical bitstream, like a PWM signal. I have no idea what you mean. Though I did qualify that it bears no relationship to any encoded signal. What is "it"? One "1", followed by one "0", then two "1"s followed by a "0" looks PWM to me. How so? It doesn't match any definition of PWM that I know of. When I talk about PWM, I mean, e.g., the type of signal shown in figure one of http://www.embedded.com/story/OEG20010821S0096 -- Randy Yates Sony Ericsson Mobile Communications Research Triangle Park, NC, USA , 919-472-1124 |
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#90
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1-Bit Wave File?
On Fri, 21 May 2004 08:40:43 +1200, "Geoff Wood"
-nospam wrote: Randy Yates wrote: Bit-depth reducing to 1 bit does not convert PCM into a PWM signal. On the other hand, I guess it does, Absolutely it does not. A PWM signal has the property that at time n*T the signal begins at a high state for p*T seconds and ends at a low state for (1-p)*T seconds, 0 = p = 1. A 1-bit bitstream does not have this property. Many people seem to have this misconception that a delta sigma bitstream is a PWM waveform. It is not - they are two different animals. I was alluding to the resultant signal being an asymetrical bitstream, like a PWM signal. Though I did qualify that it bears no relationship to any encoded signal. One "1", followed by one "0", then two "1"s followed by a "0" looks PWM to me. geoff Just to be sure - there are no digits in PWM - it is an analogies system. It is sampled, to be sure, but not digitally. d Pearce Consulting http://www.pearce.uk.com |
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#91
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1-Bit Wave File?
On Fri, 21 May 2004 08:40:43 +1200, "Geoff Wood"
-nospam wrote: Randy Yates wrote: Bit-depth reducing to 1 bit does not convert PCM into a PWM signal. On the other hand, I guess it does, Absolutely it does not. A PWM signal has the property that at time n*T the signal begins at a high state for p*T seconds and ends at a low state for (1-p)*T seconds, 0 = p = 1. A 1-bit bitstream does not have this property. Many people seem to have this misconception that a delta sigma bitstream is a PWM waveform. It is not - they are two different animals. I was alluding to the resultant signal being an asymetrical bitstream, like a PWM signal. Though I did qualify that it bears no relationship to any encoded signal. One "1", followed by one "0", then two "1"s followed by a "0" looks PWM to me. geoff Just to be sure - there are no digits in PWM - it is an analogies system. It is sampled, to be sure, but not digitally. d Pearce Consulting http://www.pearce.uk.com |
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#92
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1-Bit Wave File?
On Fri, 21 May 2004 08:40:43 +1200, "Geoff Wood"
-nospam wrote: Randy Yates wrote: Bit-depth reducing to 1 bit does not convert PCM into a PWM signal. On the other hand, I guess it does, Absolutely it does not. A PWM signal has the property that at time n*T the signal begins at a high state for p*T seconds and ends at a low state for (1-p)*T seconds, 0 = p = 1. A 1-bit bitstream does not have this property. Many people seem to have this misconception that a delta sigma bitstream is a PWM waveform. It is not - they are two different animals. I was alluding to the resultant signal being an asymetrical bitstream, like a PWM signal. Though I did qualify that it bears no relationship to any encoded signal. One "1", followed by one "0", then two "1"s followed by a "0" looks PWM to me. geoff Just to be sure - there are no digits in PWM - it is an analogies system. It is sampled, to be sure, but not digitally. d Pearce Consulting http://www.pearce.uk.com |
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#93
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1-Bit Wave File?
On Fri, 21 May 2004 08:40:43 +1200, "Geoff Wood"
-nospam wrote: Randy Yates wrote: Bit-depth reducing to 1 bit does not convert PCM into a PWM signal. On the other hand, I guess it does, Absolutely it does not. A PWM signal has the property that at time n*T the signal begins at a high state for p*T seconds and ends at a low state for (1-p)*T seconds, 0 = p = 1. A 1-bit bitstream does not have this property. Many people seem to have this misconception that a delta sigma bitstream is a PWM waveform. It is not - they are two different animals. I was alluding to the resultant signal being an asymetrical bitstream, like a PWM signal. Though I did qualify that it bears no relationship to any encoded signal. One "1", followed by one "0", then two "1"s followed by a "0" looks PWM to me. geoff Just to be sure - there are no digits in PWM - it is an analogies system. It is sampled, to be sure, but not digitally. d Pearce Consulting http://www.pearce.uk.com |
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#94
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1-Bit Wave File?
"Richard Crowley" wrote in message ...
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. You should maybe review works such as Lip****z and Vanderkooy's "Resolution below the least significant bit in audio systems with dither" from JAES before making such a pronouncement. |
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#95
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1-Bit Wave File?
"Richard Crowley" wrote in message ...
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. You should maybe review works such as Lip****z and Vanderkooy's "Resolution below the least significant bit in audio systems with dither" from JAES before making such a pronouncement. |
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#96
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1-Bit Wave File?
"Richard Crowley" wrote in message ...
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. You should maybe review works such as Lip****z and Vanderkooy's "Resolution below the least significant bit in audio systems with dither" from JAES before making such a pronouncement. |
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#97
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1-Bit Wave File?
"Richard Crowley" wrote in message ...
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. You should maybe review works such as Lip****z and Vanderkooy's "Resolution below the least significant bit in audio systems with dither" from JAES before making such a pronouncement. |
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#98
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1-Bit Wave File?
"Randy Yates" wrote in message
... "Geoff Wood" -nospam writes: Randy Yates wrote: Bit-depth reducing to 1 bit does not convert PCM into a PWM signal. On the other hand, I guess it does, Absolutely it does not. A PWM signal has the property that at time n*T the signal begins at a high state for p*T seconds and ends at a low state for (1-p)*T seconds, 0 = p = 1. A 1-bit bitstream does not have this property. Many people seem to have this misconception that a delta sigma bitstream is a PWM waveform. It is not - they are two different animals. I was alluding to the resultant signal being an asymetrical bitstream, like a PWM signal. I have no idea what you mean. Though I did qualify that it bears no relationship to any encoded signal. What is "it"? One "1", followed by one "0", then two "1"s followed by a "0" looks PWM to me. How so? It doesn't match any definition of PWM that I know of. When I talk about PWM, I mean, e.g., the type of signal shown in figure one of http://www.embedded.com/story/OEG20010821S0096 Randy, I don't see any reason why you couldn't create the waveforms shown in Fig. 1 above with a 1-bit PCM waveform, assuming sufficient sample rate. -Jon |
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#99
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1-Bit Wave File?
"Randy Yates" wrote in message
... "Geoff Wood" -nospam writes: Randy Yates wrote: Bit-depth reducing to 1 bit does not convert PCM into a PWM signal. On the other hand, I guess it does, Absolutely it does not. A PWM signal has the property that at time n*T the signal begins at a high state for p*T seconds and ends at a low state for (1-p)*T seconds, 0 = p = 1. A 1-bit bitstream does not have this property. Many people seem to have this misconception that a delta sigma bitstream is a PWM waveform. It is not - they are two different animals. I was alluding to the resultant signal being an asymetrical bitstream, like a PWM signal. I have no idea what you mean. Though I did qualify that it bears no relationship to any encoded signal. What is "it"? One "1", followed by one "0", then two "1"s followed by a "0" looks PWM to me. How so? It doesn't match any definition of PWM that I know of. When I talk about PWM, I mean, e.g., the type of signal shown in figure one of http://www.embedded.com/story/OEG20010821S0096 Randy, I don't see any reason why you couldn't create the waveforms shown in Fig. 1 above with a 1-bit PCM waveform, assuming sufficient sample rate. -Jon |
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#100
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1-Bit Wave File?
"Randy Yates" wrote in message
... "Geoff Wood" -nospam writes: Randy Yates wrote: Bit-depth reducing to 1 bit does not convert PCM into a PWM signal. On the other hand, I guess it does, Absolutely it does not. A PWM signal has the property that at time n*T the signal begins at a high state for p*T seconds and ends at a low state for (1-p)*T seconds, 0 = p = 1. A 1-bit bitstream does not have this property. Many people seem to have this misconception that a delta sigma bitstream is a PWM waveform. It is not - they are two different animals. I was alluding to the resultant signal being an asymetrical bitstream, like a PWM signal. I have no idea what you mean. Though I did qualify that it bears no relationship to any encoded signal. What is "it"? One "1", followed by one "0", then two "1"s followed by a "0" looks PWM to me. How so? It doesn't match any definition of PWM that I know of. When I talk about PWM, I mean, e.g., the type of signal shown in figure one of http://www.embedded.com/story/OEG20010821S0096 Randy, I don't see any reason why you couldn't create the waveforms shown in Fig. 1 above with a 1-bit PCM waveform, assuming sufficient sample rate. -Jon |
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#101
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1-Bit Wave File?
"Randy Yates" wrote in message
... "Geoff Wood" -nospam writes: Randy Yates wrote: Bit-depth reducing to 1 bit does not convert PCM into a PWM signal. On the other hand, I guess it does, Absolutely it does not. A PWM signal has the property that at time n*T the signal begins at a high state for p*T seconds and ends at a low state for (1-p)*T seconds, 0 = p = 1. A 1-bit bitstream does not have this property. Many people seem to have this misconception that a delta sigma bitstream is a PWM waveform. It is not - they are two different animals. I was alluding to the resultant signal being an asymetrical bitstream, like a PWM signal. I have no idea what you mean. Though I did qualify that it bears no relationship to any encoded signal. What is "it"? One "1", followed by one "0", then two "1"s followed by a "0" looks PWM to me. How so? It doesn't match any definition of PWM that I know of. When I talk about PWM, I mean, e.g., the type of signal shown in figure one of http://www.embedded.com/story/OEG20010821S0096 Randy, I don't see any reason why you couldn't create the waveforms shown in Fig. 1 above with a 1-bit PCM waveform, assuming sufficient sample rate. -Jon |
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#102
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1-Bit Wave File?
"Jon Harris" writes:
"Randy Yates" wrote in message ... "Geoff Wood" -nospam writes: Randy Yates wrote: Bit-depth reducing to 1 bit does not convert PCM into a PWM signal. On the other hand, I guess it does, Absolutely it does not. A PWM signal has the property that at time n*T the signal begins at a high state for p*T seconds and ends at a low state for (1-p)*T seconds, 0 = p = 1. A 1-bit bitstream does not have this property. Many people seem to have this misconception that a delta sigma bitstream is a PWM waveform. It is not - they are two different animals. I was alluding to the resultant signal being an asymetrical bitstream, like a PWM signal. I have no idea what you mean. Though I did qualify that it bears no relationship to any encoded signal. What is "it"? One "1", followed by one "0", then two "1"s followed by a "0" looks PWM to me. How so? It doesn't match any definition of PWM that I know of. When I talk about PWM, I mean, e.g., the type of signal shown in figure one of http://www.embedded.com/story/OEG20010821S0096 Randy, I don't see any reason why you couldn't create the waveforms shown in Fig. 1 above with a 1-bit PCM waveform, assuming sufficient sample rate. Jon, I'm not saying you can't generate PWM digitally. Yes, I agree that you can. I'm saying that when you requantize a multi-bit waveform to 1 bit (just a simple requantization, like when you requantize from 24 bits to 16 bits, but this time you go all the way down to 1 bit), the result will NOT be a PWM signal. I'm also saying that if you perform a delta sigma conversion of a multi-bit waveform to a 1-bit waveform (i.e., perform a delta sigma D/A conversion and examine the 1-bit bistream before it is converted to analog), the result will NOT be a PWM signal. -- Randy Yates Sony Ericsson Mobile Communications Research Triangle Park, NC, USA , 919-472-1124 |
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#103
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1-Bit Wave File?
"Jon Harris" writes:
"Randy Yates" wrote in message ... "Geoff Wood" -nospam writes: Randy Yates wrote: Bit-depth reducing to 1 bit does not convert PCM into a PWM signal. On the other hand, I guess it does, Absolutely it does not. A PWM signal has the property that at time n*T the signal begins at a high state for p*T seconds and ends at a low state for (1-p)*T seconds, 0 = p = 1. A 1-bit bitstream does not have this property. Many people seem to have this misconception that a delta sigma bitstream is a PWM waveform. It is not - they are two different animals. I was alluding to the resultant signal being an asymetrical bitstream, like a PWM signal. I have no idea what you mean. Though I did qualify that it bears no relationship to any encoded signal. What is "it"? One "1", followed by one "0", then two "1"s followed by a "0" looks PWM to me. How so? It doesn't match any definition of PWM that I know of. When I talk about PWM, I mean, e.g., the type of signal shown in figure one of http://www.embedded.com/story/OEG20010821S0096 Randy, I don't see any reason why you couldn't create the waveforms shown in Fig. 1 above with a 1-bit PCM waveform, assuming sufficient sample rate. Jon, I'm not saying you can't generate PWM digitally. Yes, I agree that you can. I'm saying that when you requantize a multi-bit waveform to 1 bit (just a simple requantization, like when you requantize from 24 bits to 16 bits, but this time you go all the way down to 1 bit), the result will NOT be a PWM signal. I'm also saying that if you perform a delta sigma conversion of a multi-bit waveform to a 1-bit waveform (i.e., perform a delta sigma D/A conversion and examine the 1-bit bistream before it is converted to analog), the result will NOT be a PWM signal. -- Randy Yates Sony Ericsson Mobile Communications Research Triangle Park, NC, USA , 919-472-1124 |
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#104
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1-Bit Wave File?
"Jon Harris" writes:
"Randy Yates" wrote in message ... "Geoff Wood" -nospam writes: Randy Yates wrote: Bit-depth reducing to 1 bit does not convert PCM into a PWM signal. On the other hand, I guess it does, Absolutely it does not. A PWM signal has the property that at time n*T the signal begins at a high state for p*T seconds and ends at a low state for (1-p)*T seconds, 0 = p = 1. A 1-bit bitstream does not have this property. Many people seem to have this misconception that a delta sigma bitstream is a PWM waveform. It is not - they are two different animals. I was alluding to the resultant signal being an asymetrical bitstream, like a PWM signal. I have no idea what you mean. Though I did qualify that it bears no relationship to any encoded signal. What is "it"? One "1", followed by one "0", then two "1"s followed by a "0" looks PWM to me. How so? It doesn't match any definition of PWM that I know of. When I talk about PWM, I mean, e.g., the type of signal shown in figure one of http://www.embedded.com/story/OEG20010821S0096 Randy, I don't see any reason why you couldn't create the waveforms shown in Fig. 1 above with a 1-bit PCM waveform, assuming sufficient sample rate. Jon, I'm not saying you can't generate PWM digitally. Yes, I agree that you can. I'm saying that when you requantize a multi-bit waveform to 1 bit (just a simple requantization, like when you requantize from 24 bits to 16 bits, but this time you go all the way down to 1 bit), the result will NOT be a PWM signal. I'm also saying that if you perform a delta sigma conversion of a multi-bit waveform to a 1-bit waveform (i.e., perform a delta sigma D/A conversion and examine the 1-bit bistream before it is converted to analog), the result will NOT be a PWM signal. -- Randy Yates Sony Ericsson Mobile Communications Research Triangle Park, NC, USA , 919-472-1124 |
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#105
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1-Bit Wave File?
"Jon Harris" writes:
"Randy Yates" wrote in message ... "Geoff Wood" -nospam writes: Randy Yates wrote: Bit-depth reducing to 1 bit does not convert PCM into a PWM signal. On the other hand, I guess it does, Absolutely it does not. A PWM signal has the property that at time n*T the signal begins at a high state for p*T seconds and ends at a low state for (1-p)*T seconds, 0 = p = 1. A 1-bit bitstream does not have this property. Many people seem to have this misconception that a delta sigma bitstream is a PWM waveform. It is not - they are two different animals. I was alluding to the resultant signal being an asymetrical bitstream, like a PWM signal. I have no idea what you mean. Though I did qualify that it bears no relationship to any encoded signal. What is "it"? One "1", followed by one "0", then two "1"s followed by a "0" looks PWM to me. How so? It doesn't match any definition of PWM that I know of. When I talk about PWM, I mean, e.g., the type of signal shown in figure one of http://www.embedded.com/story/OEG20010821S0096 Randy, I don't see any reason why you couldn't create the waveforms shown in Fig. 1 above with a 1-bit PCM waveform, assuming sufficient sample rate. Jon, I'm not saying you can't generate PWM digitally. Yes, I agree that you can. I'm saying that when you requantize a multi-bit waveform to 1 bit (just a simple requantization, like when you requantize from 24 bits to 16 bits, but this time you go all the way down to 1 bit), the result will NOT be a PWM signal. I'm also saying that if you perform a delta sigma conversion of a multi-bit waveform to a 1-bit waveform (i.e., perform a delta sigma D/A conversion and examine the 1-bit bistream before it is converted to analog), the result will NOT be a PWM signal. -- Randy Yates Sony Ericsson Mobile Communications Research Triangle Park, NC, USA , 919-472-1124 |
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#107
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1-Bit Wave File?
On Thu, 20 May 2004 21:37:27 GMT, (Don Pearce)
wrote: On Fri, 21 May 2004 08:40:43 +1200, "Geoff Wood" -nospam wrote: Randy Yates wrote: Bit-depth reducing to 1 bit does not convert PCM into a PWM signal. On the other hand, I guess it does, Absolutely it does not. A PWM signal has the property that at time n*T the signal begins at a high state for p*T seconds and ends at a low state for (1-p)*T seconds, 0 = p = 1. A 1-bit bitstream does not have this property. Many people seem to have this misconception that a delta sigma bitstream is a PWM waveform. It is not - they are two different animals. I was alluding to the resultant signal being an asymetrical bitstream, like a PWM signal. Though I did qualify that it bears no relationship to any encoded signal. One "1", followed by one "0", then two "1"s followed by a "0" looks PWM to me. geoff Just to be sure - there are no digits in PWM - it is an analogies system. It is sampled, to be sure, but not digitally. d Pearce Consulting http://www.pearce.uk.com Good old spell-checker! Make that "analogue". d Pearce Consulting http://www.pearce.uk.com |
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1-Bit Wave File?
On Thu, 20 May 2004 21:37:27 GMT, (Don Pearce)
wrote: On Fri, 21 May 2004 08:40:43 +1200, "Geoff Wood" -nospam wrote: Randy Yates wrote: Bit-depth reducing to 1 bit does not convert PCM into a PWM signal. On the other hand, I guess it does, Absolutely it does not. A PWM signal has the property that at time n*T the signal begins at a high state for p*T seconds and ends at a low state for (1-p)*T seconds, 0 = p = 1. A 1-bit bitstream does not have this property. Many people seem to have this misconception that a delta sigma bitstream is a PWM waveform. It is not - they are two different animals. I was alluding to the resultant signal being an asymetrical bitstream, like a PWM signal. Though I did qualify that it bears no relationship to any encoded signal. One "1", followed by one "0", then two "1"s followed by a "0" looks PWM to me. geoff Just to be sure - there are no digits in PWM - it is an analogies system. It is sampled, to be sure, but not digitally. d Pearce Consulting http://www.pearce.uk.com Good old spell-checker! Make that "analogue". d Pearce Consulting http://www.pearce.uk.com |
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#109
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1-Bit Wave File?
On Thu, 20 May 2004 21:37:27 GMT, (Don Pearce)
wrote: On Fri, 21 May 2004 08:40:43 +1200, "Geoff Wood" -nospam wrote: Randy Yates wrote: Bit-depth reducing to 1 bit does not convert PCM into a PWM signal. On the other hand, I guess it does, Absolutely it does not. A PWM signal has the property that at time n*T the signal begins at a high state for p*T seconds and ends at a low state for (1-p)*T seconds, 0 = p = 1. A 1-bit bitstream does not have this property. Many people seem to have this misconception that a delta sigma bitstream is a PWM waveform. It is not - they are two different animals. I was alluding to the resultant signal being an asymetrical bitstream, like a PWM signal. Though I did qualify that it bears no relationship to any encoded signal. One "1", followed by one "0", then two "1"s followed by a "0" looks PWM to me. geoff Just to be sure - there are no digits in PWM - it is an analogies system. It is sampled, to be sure, but not digitally. d Pearce Consulting http://www.pearce.uk.com Good old spell-checker! Make that "analogue". d Pearce Consulting http://www.pearce.uk.com |
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#110
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1-Bit Wave File?
Dick Pierce wrote:
"Richard Crowley" wrote in message ... 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. We all know that data coming one bit at a time can be useful: this message will be transmitted that way. According to what he asked for, the OP wants to strip all but the sign bit from a wave file in hopes of getting "that old movie sound". You should maybe review works such as Lip****z 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. Jerry -- Engineering is the art of making what you want from things you can get. ŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻ ŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻ |
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#111
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1-Bit Wave File?
Dick Pierce wrote:
"Richard Crowley" wrote in message ... 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. We all know that data coming one bit at a time can be useful: this message will be transmitted that way. According to what he asked for, the OP wants to strip all but the sign bit from a wave file in hopes of getting "that old movie sound". You should maybe review works such as Lip****z 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. Jerry -- Engineering is the art of making what you want from things you can get. ŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻ ŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻ |
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#112
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1-Bit Wave File?
Dick Pierce wrote:
"Richard Crowley" wrote in message ... 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. We all know that data coming one bit at a time can be useful: this message will be transmitted that way. According to what he asked for, the OP wants to strip all but the sign bit from a wave file in hopes of getting "that old movie sound". You should maybe review works such as Lip****z 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. Jerry -- Engineering is the art of making what you want from things you can get. ŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻ ŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻ |
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#113
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1-Bit Wave File?
Dick Pierce wrote:
"Richard Crowley" wrote in message ... 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. We all know that data coming one bit at a time can be useful: this message will be transmitted that way. According to what he asked for, the OP wants to strip all but the sign bit from a wave file in hopes of getting "that old movie sound". You should maybe review works such as Lip****z 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. Jerry -- Engineering is the art of making what you want from things you can get. ŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻ ŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻ |
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#114
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1-Bit Wave File?
Me wrote in message ...
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.com |
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#115
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1-Bit Wave File?
Me wrote in message ...
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.com |
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#116
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1-Bit Wave File?
Me wrote in message ...
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.com |
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#117
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1-Bit Wave File?
Me wrote in message ...
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.com |
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#118
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1-Bit Wave File?
"Jon Harris" wrote in message ... "Richard Crowley" wrote in message ... Of course true "1-bit" audio is indistinguishable from random noise. Not really. DSD is one bit (at a very high sampling rate) and certainly doesn't sound like random noise. Even with "regular" sample rates such as 44.1kHz, 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 you recorded at very low levels on a medium such as cassette tape, but the ear is pretty good 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. |
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#119
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1-Bit Wave File?
"Jon Harris" wrote in message ... "Richard Crowley" wrote in message ... Of course true "1-bit" audio is indistinguishable from random noise. Not really. DSD is one bit (at a very high sampling rate) and certainly doesn't sound like random noise. Even with "regular" sample rates such as 44.1kHz, 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 you recorded at very low levels on a medium such as cassette tape, but the ear is pretty good 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. |
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#120
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1-Bit Wave File?
"Jon Harris" wrote in message ... "Richard Crowley" wrote in message ... Of course true "1-bit" audio is indistinguishable from random noise. Not really. DSD is one bit (at a very high sampling rate) and certainly doesn't sound like random noise. Even with "regular" sample rates such as 44.1kHz, 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 you recorded at very low levels on a medium such as cassette tape, but the ear is pretty good 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. |
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