A simple-to-use sound file writer

[Steve Holden]

Alf P. Steinbach wrote:
> * Steve Holden:
>> Alf P. Steinbach wrote:
>>> * Lie Ryan:
>>>> On 01/15/10 05:42, Alf P. Steinbach wrote:
>>>>> I'm beginning to believe that you maybe didn't grok that simple
>>>>> procedure.
>>>>>
>>>>> It's very very very trivial, so maybe you were looking for something
>>>>> more intricate  --  they used to say, in the old days, "hold on, this
>>>>> proof goes by so fast you may not notice it!"
>>>> Since you said it's trivial, then...
>>> You can't get it more trivial.
>>>
>>>
>>>>>> Nothing about you there. Just the information you are promoting. I
>>>>>> don't
>>>>>> normally deal in innuendo and personal attacks. Though I do
>>>>>> occasionally
>>>>>> get irritated by what I perceive to be hogwash. People who know me
>>>>>> will
>>>>>> tell you, if I am wrong I will happily admit it.
>>>>> There's a difference between an algorithm that you can implement, and
>>>>> hogwash.
>>>> please prove your claim by writing that algorithm in code and post
>>>> it in
>>>> this list. The program must accept a .wav file (or sound format of your
>>>> choice) and process it according to your algorithm and the output
>>>> another .wav file (or sound format of your choice) that sounds roughly
>>>> similar to the input file.
>>> First, the (very very trivial) algorithm I posted does *not* do that: by
>>> itself it represents a sine wave, not an arbitrary wave form.
>>>
>>> And second I'm not about to write Fourier transform code to satisfy
>>> someone who refuses to do a milligram of thinking.
>>>
>>> The Fourier part stuff needed to do what you're requesting is
>>> non-trivial, or at least it's some work to write the code.
>>>
>>>
>>>> PS: I have near-zero experience with sound processing
>>>> PPS: I will be equally delighted seeing either Steve admitting his
>>>> wrong
>>>> or you admit your hogwash
>>>> PPPS: An alternative way to convince us is to provide a paper/article
>>>> that describes this algorithm.
>>>> PPPPS: Though I will be quite sad if you choose to reject the challenge
>>> I don't believe any of what you write here.
>>>
>> Well, it seems quite reasonable to me, but then I'm not the one being
>> challenged to write a trivial algorithm.
> 
> You're again into innuendo, misleading statements and so forth. Lie
> Ryan's challenge is nothing but trivial, because it's about implementing
> very much more than the algorithm. I did implement the algorithm for
> him, in Python, and posted that in this thread.
> 
> 
>> I will, however, observe that your definition of a square wave is what I
>> would have to call a "'square' wave" (and would prefer to call a "pulse
>> train"), as I envisage a square wave as a waveform having a 50% duty
>> cycle, as in
>>
>>  ___     ___
>> |   |   |   |
>> |   |   |   |
>> |   |   |   |
>> +---+---+---+---+ and so on ad infinitum, (though I might allow you
>>     |   |   |   |                          to adjust the position
>>     |   |   |   |                          of y=0 if you want)
>>     |___|   |___|
>>
>> as opposed to your
>>
>>          _
>>         | |
>>         | |
>>   ______| |______   ______
>>                  | |
>>                  | |
>>                  |_|
>>
> 
> Try to read again, a sufficient number of times, how to generate the
> latter by summing *two instances of the former*.
> 
> I'm sorry to say this but I find it hard to explain things simple enough
> for you, because at the level of 2+2 any explanation is far more complex
> than the concept itself.
> 
> That is, of course, a challenge to me! :-)
> 
> So, thanks for challenging my pedagogical abilities.
> 
> I know they're not as good as they should be, and need some exercise!
> 
> 
>> So I can see how we might be at cross purposes. I could cite authorities
>> for differentiating between a square wave and a symmetric pulse train,
>> but will content myself with observing only that my impression is the
>> common definition of an ideal square wave (one with a zero transition
>> time) admits of only two instantaneous values, eschewing the zero you
>> use. If that is the case, we could perhaps agree that we differ merely
>> on terminology.
> 
> No, we don't differ on terminology: we seem to differ in that one of us
> has severe difficulties understanding the very simplest things, such as
> what graph one gets by summing two squares waves of same frequency but
> out of phase.
> 
> The one of us who has trouble understanding that is also apparently too
> lazy to try out the earlier advice given him of graphing this on a piece
> of paper, and instead prefers to spout innuendu, personal attacks and
> misleading statements.
> 
> That's a real challenge to the other person.
> 
> 
>> Or, best of all, you could show me how to synthesize any waveform by
>> adding square waves with a 50% duty cycle.  Then I *will* be impressed.
> 
> You would, yes?
> 
> Perhaps you'd also admit to being wrong, and retract your innuoendo etc.?
> 
> Well, just epress the waveform as a sum of sine waves (Fourier
> transform); synthesize each sine wave by a set of 50% duty cycle square
> waves (I've earlier posted Python code for that in this thread); add all
> the square waves. The hard part of this is implementing the Fourier
> transform, I leave that to you. ;-)
> 
Finally, I think, the penny is beginning to drop. Give me a little more
time to think about it and I can see I might be willing to write the
words "I was wring". Shame about my typing, isn't it? ;-)

regards
 Steve
-- 
Steve Holden           +1 571 484 6266   +1 800 494 3119
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