Reply by Andor January 18, 20082008-01-18
On 18 Jan., 17:38, Jerry Avins <j...@ieee.org> wrote:
> Rune Allnor wrote: > > On 18 Jan, 17:10, "Martin Blume" <mbl...@socha.net> wrote: > >> "Rune Allnor" schrieb > > >>>> But then, recognizing is different from and IMHO > >>>> much easier than separating. > >>> By means of DSP? What's the difference? How can you > >>> recognize something if you can't separate it from > >>> its surroundings? > > ... > >> As an example, it is easier to tell that a piano is present > >> in a classical recording, but extracting (separating) the > >> piano part is much more difficult. > > > By means of DSP or by listening? > > DSP as currently practiced, or as it might develop in another 50 years?
African or European swallow, sorry, DSP? :-)
Reply by Martin Blume January 18, 20082008-01-18
"Rune Allnor" schrieb
> > > > > > But then, recognizing is different from and IMHO > > > > much easier than separating. > > > > > By means of DSP? What's the difference? How can you > > > recognize something if you can't separate it from > > > its surroundings? > ... > > As an example, it is easier to tell that a piano is > > present in a classical recording, but extracting > > (separating) the piano part is much more difficult. > > By means of DSP or by listening? >
Both. Note that I didn't say anthing about the absolute level of difficulty of doing it, I just said that it would be easier to do recognition than extraction. IIRC, I read / heard somewhere that (very) good musician can write down the notes of a particular part (*) of a piece of music. A parametric extraction might (or might not) work like this: Assume that we know what instruments are played in the piece and "what they sound like" (**). So we could try to fit sum_over_instruments_i(notes(i)*"what they sound like"(notes(i)))(dT) to record(dT). Another way would be to record it with n microphones and locating the individual instruments. Although I have outlined two possible approaches, I am not confident that these could be made to work. But perhaps the OP can try it out :-) Regards Martin (*) I am not very musical and not fluid with musical language. Here, I mean the part that a certain single music instrument is playing. Heck, I sound like a lawyer :-( (**) the timbre, or to quote http://en.wikipedia.org/wiki/Timbre: " ... For example, timbre is what, with a little practice, people use to distinguish the saxophone from the trumpet in a jazz group, even if both instruments are playing notes at the same pitch and amplitude. ..."
Reply by Jerry Avins January 18, 20082008-01-18
Rune Allnor wrote:
> On 18 Jan, 17:10, "Martin Blume" <mbl...@socha.net> wrote: >> "Rune Allnor" schrieb >> >>>> But then, recognizing is different from and IMHO >>>> much easier than separating. >>> By means of DSP? What's the difference? How can you >>> recognize something if you can't separate it from >>> its surroundings? > ... >> As an example, it is easier to tell that a piano is present >> in a classical recording, but extracting (separating) the >> piano part is much more difficult. > > By means of DSP or by listening?
DSP as currently practiced, or as it might develop in another 50 years? Jerry -- Engineering is the art of making what you want from things you can get. &#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;
Reply by Rune Allnor January 18, 20082008-01-18
On 18 Jan, 17:10, "Martin Blume" <mbl...@socha.net> wrote:
> "Rune Allnor" schrieb > > > > But then, recognizing is different from and IMHO > > > much easier than separating. > > > By means of DSP? What's the difference? How can you > > recognize something if you can't separate it from > > its surroundings?
...
> As an example, it is easier to tell that a piano is present > in a classical recording, but extracting (separating) the > piano part is much more difficult.
By means of DSP or by listening? Rune
Reply by Martin Blume January 18, 20082008-01-18
"Rune Allnor" schrieb
> > > But then, recognizing is different from and IMHO > > much easier than separating. > > By means of DSP? What's the difference? How can you > recognize something if you can't separate it from > its surroundings? >
Sorry, I wasn't clear about the wording. Recognizing, as used in my post, is being able to tell if a given component (*) is present in the recording. Separating, then, is extracting this complete component (and hopefully all the component and only the component) from this recording. Ok, extracting might be a better word. Sorry. As an example, it is easier to tell that a piano is present in a classical recording, but extracting (separating) the piano part is much more difficult. Hope this clears up the misunderstanding. My fault. Martin (*) component from the OP's post: "Im trying to find software that allows me to import a song from a band and have that sound broken down into all its different components (like in CSI [...]"
Reply by Rune Allnor January 18, 20082008-01-18
On 18 Jan, 16:24, "Martin Blume" <mbl...@socha.net> wrote:

> But then, recognizing is different from and IMHO much > easier than separating.
By means of DSP? What's the difference? How can you recognize something if you can't separate it from its surroundings? Rune
Reply by Martin Blume January 18, 20082008-01-18
"Rune Allnor" schrieb
> > Im trying to find software that allows me to import a song > > from a band and have that sound broken down into all its > > different components (like in CSI ... > > Can't be done by means of DSP. It's as simple as that. Why? > Well, it is said that parent penguins can locate their > offspring by the sound alone, in a colony comprising tens > of thousands of penguins where all the penguins call for > parents or offspring at the same time. >
Even when there were dozens of kids on the playground, I could tell when mine was whining. Does that qualify me as a penguin? I think that a parent's neural networks are trained to recognize their offspring even under the harsh environmental conditions of a playground :-) But then, recognizing is different from and IMHO much easier than separating. Separating might work to some extent if you do a parametric estimation. Just my 2 cents. Maybe even less. Martin
Reply by VelociChicken January 18, 20082008-01-18
> Im trying to find software that allows me to import a song from a band and > have that sound broken down into all its different components (like in CSI > when they have all the different sound waves and can listen to each one > individually).. not sure if this is possible so any suggestions would be > helpful
The bass guitar and the hi-hats/cymbals will be fairly isolatable because of the frequency locations. But don't expect any miracles. If you have some software with a multi-band equaliser, try cutting everything but a narrow band and sweep this up and down the spectrum - you'll soon get a good idea of what's possible. In the early days of stereo, instruments were often panned to the extreme left and right, making them easy to sample out these days! : )
Reply by Rune Allnor January 18, 20082008-01-18
On 17 Jan, 23:49, "jrsmith5601" <jrsmith5...@gmail.com> wrote:
> Im trying to find software that allows me to import a song from a band and > have that sound broken down into all its different components (like in CSI > when they have all the different sound waves and can listen to each one > individually).. not sure if this is possible so any suggestions would be > helpful
What do you mean by "component"? Somethind similar to isolating individual instruments in the band? Can't be done by means of DSP. It's as simple as that. Why? Well, it is said that parent penguins can locate their offspring by the sound alone, in a colony comprising tens of thousands of penguins where all the penguins call for parents or offspring at the same time. What does the story tell us about the penguins? It tells that they have an auditory system which is perfectly tuned to the task of finding their relatives amongst tens of thousands of their kind. Which, BTW, makes perfect sense, from a survival point of view. What does that tell us about the noises the penguins make? Nothing at all. The noise they make is so completely into grips with ther auditory system that one makes no sense without the other. Asking a person to automize a method to isolate one particular voice in a crowd or instrument in a band is similar to as somebody to find one particular penguin squeak in the colony. We, as humans, think the former is easy because we can do that in our minds. When faced with the penguin problem we might adopt a different view, for the sole reason that we have no personal experience with the problem and can evaluate the problem from a more balanced point of view. Rune
Reply by Vladimir Vassilevsky January 17, 20082008-01-17

glen herrmannsfeldt wrote:

> One that I have wondered about is using phase and amplitude > differences in stereo signals to detect and separate out parts.
Despite of the popular belief, there is generally not too much of the correlation between the left and the right channels.
> Or maybe correlation of harmonics in signals (especially musical > ones) that have significant amounts of them.
Every time you take the same note on a musical instrument, the waveform has some random variations. Modern synthesizers do that, too. It improves the naturalness.
> Though I suppose the easiest, and as far as I know still hard, > is removing 60Hz hum, including all the harmonics.
The problem with the power hum is that it is not just 60Hz and its harmonics. Vladimir Vassilevsky DSP and Mixed Signal Design Consultant http://www.abvolt.com