What is resampling?

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I guess the confusion with the term "resampling" comes really from the confusion with the term "sampling". In technical language, "sampling" means taking (eg recording or calculating) samples of some continuous signal (eg audio, image, whatever) in order to create a discrete representation of finite data-points. If the original signal was band-limited (as per Nyquist-Shannon), we can then reconstruct the original signal from the samples (exactly, in theory anyway).

With the above "definition" of sampling, resampling then simply refers to (at least conceptually) reconstructing the continuous signal and sampling it again (possibly some additional band-limiting filters in between).

However, for whatever ignorant reasons musicians and/or audio engineers of the past decided to start calling the complete collections data-points (ie "sampled signals") simply "samples" which leads to the present ambiguity: is "sample" a single recorded value, or a collection of such values that represents a complete signal? From the latter definition of the word we then get the process of "sampling" which I guess roughly means "doing stuff with the samples" which logically leads to a definition of "resampling" as "doing stuff with the samples multiple times".

Anyway, stop calling you .wav files and whatever samples. That's incorrect, because the file REALLY contains a complete signal, composed of a reasonably large number of individual samples. Isn't that obvious, no?

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quayquay17 wrote:I'm glad everyone has their own definition of the word. What OP was asking is what do stupid uneducated subspecies such as EDM producers mean when they say resample, and in that case, it means bouncing to audio to reapply effects, slice, and rearrange.
Yeah bro, it means dey take da sh*t, an' they do sh*t to it. If it sounds kinda gay after dat sh*t, dey keep doing diff'rent sh*t, till tha gaynezz goez aways, aiight? ...but if that sh*t's sick, they be sample'n all up in that b*tch to use on 'dere beat an' sh*zzle!

(Sorry, I just watched the mentioned film out of curiosity ) :hihi:
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Yes and guitarists are all idiots because they say "Amp" although amplification is only a portion of what modern guitar amplification, coloration, and and frequency calibration units do. Yet since a musician does not need to be a technician in order to make meaningful music, we refer to them as amps.

:shock:

Who cares what it's called at all? all names are for is to convey meaning to another person. If the relevant people know what someone means by resampling, then it's working! Obviously OP was confused, but that was cleared up 3 pages ago.
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mystran wrote:Anyway, stop calling you .wav files and whatever samples. That's incorrect, because the file REALLY contains a complete signal, composed of a reasonably large number of individual samples. Isn't that obvious, no?
perfectly reasonable. although it's also reasonable to apply context to understand the complete meaning. as a technical term "sample" means a discrete data point. although it isn't entirely incorrect to use "sample" to refer to an array of samples either. if you've sampled the same signal at different times, each "sample" in the array can be thought of as a single point in a vector, sample[t] of course. so that's not totally off base.

it also isn't wrong to refer to a sampled signal as "samples" in the plural.

so either way it's fine.

no matter what you do here, while i agree it's potentially one of the sources of confusion, i don't agree that it wo9uld inherently change the definition of "sampling" or "re-sampling" if it were used in that way. just because you end up with a sample with a time axis when you do any "sampling", it doesn't mean that "re-sampling" suddenly doesn't involve actually sampling anything just because you're prefixed it with "re-".

it's simply impossible to sample anything without having a continuous signal to sample from.

what causes the definition of "sample" to change is called "ignorance".
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quayquay17 wrote:Who cares what it's called at all?
all depends upon the context. using the term "amp" can be equally as ambiguous as "sample" or "re-sampling". when we're talking about a tremolo chorus, we don't go and call that an amp. it's a part of some amps and was labelled "chorus" even though it was actually a tremolo. so what we'd say instead is "tremolo chorus from an amp" or something to be really clear on what we're referring to.

same thing with sampling. if you start calling what you do "re-sampling" instead of "processing and building up layered samples" you're adding layer upon layer of ambiguity.

we already have the issue of "samples" referring to a sampled signal, which is sort of acceptable given that we assume it refers to sample[t], which is a vector and not just a scalar. we can also use it to refer to multidimensional vectors including velocity, accenting and various other properties. sometimes also referred to as a "wave-table" although that isn't really much more clear.

when we start to take that already layered definition, throw out the context and tack on another layer of "processing and layering existing signals to produce the result" it gets really confusing.

you could invent another new term for this... like, erm... globbing.

that would actually just be recycling of an extinct unix term. replaced by regex, so glob is probably (or globurly) available to be used some other place.
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quayquay17 wrote:Yes and guitarists are all idiots
Empirical observations largely support this claim.

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mystran wrote:However, for whatever ignorant reasons musicians and/or audio engineers of the past decided to start calling the complete collections data-points (ie "sampled signals") simply "samples" which leads to the present ambiguity: is "sample" a single recorded value, or a collection of such values that represents a complete signal? From the latter definition of the word we then get the process of "sampling" which I guess roughly means "doing stuff with the samples" which logically leads to a definition of "resampling" as "doing stuff with the samples multiple times".

Anyway, stop calling you .wav files and whatever samples. That's incorrect, because the file REALLY contains a complete signal, composed of a reasonably large number of individual samples. Isn't that obvious, no?
"Tell me some more about your excessive need for order..."

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LBN wrote:
mystran wrote:However, for whatever ignorant reasons musicians and/or audio engineers of the past decided to start calling the complete collections data-points (ie "sampled signals") simply "samples" which leads to the present ambiguity: is "sample" a single recorded value, or a collection of such values that represents a complete signal? From the latter definition of the word we then get the process of "sampling" which I guess roughly means "doing stuff with the samples" which logically leads to a definition of "resampling" as "doing stuff with the samples multiple times".

Anyway, stop calling you .wav files and whatever samples. That's incorrect, because the file REALLY contains a complete signal, composed of a reasonably large number of individual samples. Isn't that obvious, no?
"Tell me some more about your excessive need for order..."
fnord.

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Sendy wrote:
quayquay17 wrote:I'm glad everyone has their own definition of the word. What OP was asking is what do stupid uneducated subspecies such as EDM producers mean when they say resample, and in that case, it means bouncing to audio to reapply effects, slice, and rearrange.
Agreed, but what these uneducated producers call resampling, is just "Sampling". Sampling is all about processing and manipulating. Why assign a term resampling? That just seems to highlight they don't know anything about the art of sampling, and indeed digital audio.
James McFadyen
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we've already talked about this though. now we have to come up with a theory about why they've misconstrued the meaning of the term sample that has something to do with their mothers.

in fact sampling is an entire musical genre with a great many totally awesome tracks in it. you use nothing but a sampler. you don't even play notes, you just chop shit up.

of course for years this was considered a "not a genre but quite simply pure crap" genre and perhaps still is. it has it's gems though.

http://www.soundonsound.com/sos/dec98/a ... mp.318.htm
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Work less; get more done.

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I think it's just a case of people don't know what they don't know. Happens in all walks of life.

No shame in ignorance, but if people just don't know, they will adapt and make their own means.

However what I cannot stand, is when ignorant people (not ignorant to other peoples opinion, but educationally ignorant) trying to justify their means for the reasoning, unknown to them that they reasoning is fabricated from ignorance itself.

And so it continues. But let's not be fooled, we are all ignorant in some ways - that is why we learn.

Education is key here - or at least a certain level of self-learning based on truth.
James McFadyen
Composer

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highkoo wrote:
seismic1 wrote:
highkoo wrote:wtf?
AD, is this guy wasting his time?
Is desampling a waste of time, or merely cost-effective? :?
Sorry seismic, I was just messing with you because you happened to be the guy that posted.


Don't worry, I'd figured that out on my lonesome :)
highkoo wrote: Well, and cuz your post seemed informed. :P
:lol: I got away with that one
highkoo wrote:
Measuring earthquake data does seem a little dubious to me though because I think we cause half of them now.
Oil exploration is probably the main application of these techniques.
aciddose wrote: that would actually just be recycling of an extinct unix term. replaced by regex, so glob is probably (or globurly) available to be used some other place.
I still have some tcsh scripts kicking about which contain strategically placed set/unset noglob statements. :shock:

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actually i think perl and other languages have a glob function which is actually used fairly often.

reasonably though... i'm not entirely sure. it might be reasonable to use the term. or "layers" or something at least. if you say "i globbed a trumpet on a rhodes and added a phaser" i hope only the real neck-beards will be picturing the string "trumpet * rhodes phaser" :hihi:
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The coder's credo: We believe our work is neither clever nor difficult; it is done because we thought it would be easy.
Work less; get more done.

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aciddose wrote:actually i think perl and other languages have a glob function which is actually used fairly often.
I've mostly seen "glob" used a synonym for the "wildcard" syntax that shells accept (and that's pretty much what the Perl glob does too), but most importantly it's not really interchangeable with "regex", because regex is short for regular expression, which can be used to express regular grammars, which in turn have the computational power of finite-state automata.

Globs are much more limited; eg using the usual syntax, /ab+c/ is a simple regular expression that matches any string consisting of "a" followed by one or more "b" characters, followed by a "c". There's no way to do this in any normal glob-syntax though, because we don't have the Kleene star for repetition. Likewise /(foo)|(bar)/ would match either "foo" or "bar" but you can't really do this in globs either, because while you can (usually) pick one from a set of characters, you can't group characters into words and pick one of the complete words.

Hence, globs are useful for stuff where you want to pick all the files with the word "error" and ending ".log" (eg "*error*.log"), but there's plenty of useful stuff that's just impossible (which is why "find .|grep 'whatever'|xargs barf" isn't exactly uncommon in shell-scripts).

Now, modern Unix "regular expressions" like those accepted by PCRE or whatever are not actually "regular expression" because they typically have extensions that cannot be implemented as FSM but the point is: when the term "regex" is used you generally expect AT LEAST the expressive power of formal regular expressions.

Anyway, if you really want to hi-jack the "glob" term, go ahead, but for the classic meaning "wildcard" is much better substitute than "regex"

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yeah i was going to mention that. what i meant though was that you can replace globs with a regex.. i should have been clearer. anything a glob can do can be done via regex.. wildcard is probably a good replacement term and i've only ever seen glob commonly used by the older unix users.

there must be a similar term these new-age retro samplists can use though. samplism? it's like a prism for samples.

a goopey? i gooped up some vocals with a banjo and mic'd that going through my tremolo chorus amp, yo dawg i heard you like banjo on your banjo so i played back your banjo on a banjo, mic'd it and used that as a convolution impulse for your banjo.
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Work less; get more done.

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