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Groups > comp.lang.basic.visual.misc > #650

Re: The Beep Function.

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"Peter Nolan" <peter.nolan40@gmail.com> wrote in message 
news:b064af06-d5b9-4181-8d1a-d5e2d3e0b073@r5g2000yqc.googlegroups.com...
On Jan 13, 11:06 am, "DaveO" <d...@dial.pipex.com> wrote:
>> So what's the problem? Ramping a variable for the first and
>> last n steps of a loop is pretty trivial however I've no idea if
>> it will actually work to fade in and out the WAV, the easiest
>> way to find out would be to try it out.
>
> Hello DaveO. Softening up the WAV file using ramps at the
> start and finish of the file will definitely work because I have
> checked all this out using Audacity. It's just a matter of getting
> the code to build in the two ramp functions to work and then
> playing round with the slope of that function to eliminate the pops.

I hope you don't take this the wrong way Peter but I'm having a little 
trouble reconciling your desire to "know what goes on under the hood" with 
your reluctance to have a go at modifying the existing wav file code in 
order to produce the fade in and the fade out sections.

Don't worry about writing code that fails to work first time, or even that 
fails to work at all. We all do that sometimes. In fact we all do it a lot, 
if we are honest with ourselves. That's how we learn. If it fails to work 
first time then try again. If after trying for some time you find that you 
just cannot get it at all then you haven't lost anything, except perhaps a 
bit of time, and you might actually have learned quite a lot. Also, the 
people here will be far more inclined to help you with the details of your 
code if you have tried and failed than they will if you have never tried at 
all. As a starter, have a look at the declaration of the main array in the 
example code, which is as follows:

ReDim wavfile(1 To totalsamples + 22)

That array is an array of VB Integers. The first 22 elements of it contain 
the "description of the wav file" and the remaining elements contain the 
actual sample voltage data. So, for simplicity you could start off by 
declaring two new variables that contain the start point and the end point 
of the actual wave data samples in the wavfile array, perhaps something 
like:

Dim FirstSample as Long, LastSample as Long
FirstSample = 23
LastSample = totalSamples + 22

Next you need to decide how many samples you want to modify at each end in 
order to create the fade-in and the fade-out so as to reduce or eliminate 
the "blip noise". My own suggestion is to start off using about one 
hundredth of a second at each end of the total waveform. If this doesn't 
reduce the "pop" sufficiently then use a larger value, perhaps two, three or 
four hundredths of a second (although I think the first one will work for 
you). This particular code always generates a wav file at the sample rate of 
44100 samples per second (what used to be known as the standard "CD music" 
rate). So, if there are always 44100 samples in one second then there will 
always be 441 samples in one hundredth of a second, regardless of the sine 
wave frequency of the tone the code is generating. So that gets you another 
variable you can declare and populate:

SlopeSamples = 441

I would suggest that for simplicity you tackle the "fade-in" section first. 
Also, both for simplicity and for speed, I would suggest that you add your 
own "fade-in" code AFTER the main waveform has been fully created, in other 
words AFTER the following section in the existing code:

For n = 0 To totalsamples - 1
d1 = Amplitude * Sin(k)
    wavfile(n + 23) = d1
    k = k + dAngle
Next n

So, immediately after the code shown above you will need to add your own 
variable declarations and populate them with the correct values (as already 
explained above) and you will need to add your own For . . . Next loop for 
the "Fade In" code which (for this simple linear fade) reads one by one the 
first 441 actual data samples and modifies each of them by multiplying it by 
some value in the range zero to 1 and and dumps it back. For the "fade-in" 
the 441 samples should in turn be multiplied by a floating point value which 
gradually increases from zero to one over the complete 441 samples.

When you think you have got it right then run the program and see what 
happens. Make sure that you uncomment the lines near the end of the code so 
that an actual .wav file is saved to disk. If your code runs without error 
you can then load that .wav file into Audacity and see what it looks like. 
You should be able to see the short one hundredth of a second "ramp up from 
zero" of the waveform.

Give it a go, Peter. You'll learn much more by trying than you will by 
reading code that has been posted. In fact you will probably learn much more 
by trying and failing than you will be trying and succeeding. Believe me.

Mike

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The Beep Function. Peter Nolan <peter.nolan40@gmail.com> - 2012-01-04 06:15 -0800
  Re: The Beep Function. Peter Nolan <peter.nolan40@gmail.com> - 2012-01-04 07:11 -0800
  Re: The Beep Function. "Mike Williams" <Mike@WhiskyAndCoke.com> - 2012-01-04 15:38 +0000
  Re: The Beep Function. "Mike Williams" <Mike@WhiskyAndCoke.com> - 2012-01-04 16:16 +0000
    Re: The Beep Function. Peter Nolan <peter.nolan40@gmail.com> - 2012-01-04 10:15 -0800
      Re: The Beep Function. Jim Mack <no-uce-ube@mdxi.com> - 2012-01-04 13:46 -0500
        Re: The Beep Function. Peter Nolan <peter.nolan40@gmail.com> - 2012-01-05 08:09 -0800
      Re: The Beep Function. "Mike Williams" <Mike@WhiskyAndCoke.com> - 2012-01-04 22:24 +0000
      Re: The Beep Function. "Mike Williams" <Mike@WhiskyAndCoke.com> - 2012-01-05 08:22 +0000
      Re: The Beep Function. "Mike Williams" <Mike@WhiskyAndCoke.com> - 2012-01-05 09:21 +0000
        Re: The Beep Function. Gordon Levi <gordon@address.invalid> - 2012-01-05 21:54 +1100
          Re: The Beep Function. "Mike Williams" <Mike@WhiskyAndCoke.com> - 2012-01-05 11:33 +0000
            Re: The Beep Function. Gordon Levi <gordon@address.invalid> - 2012-01-06 00:20 +1100
              Re: The Beep Function. "Mike Williams" <Mike@WhiskyAndCoke.com> - 2012-01-05 17:46 +0000
                Re: The Beep Function. "blank" <blank@blankety.blank.com> - 2012-01-06 14:03 +1100
                Re: The Beep Function. Gordon Levi <gordon@address.invalid> - 2012-01-08 00:43 +1100
                Re: The Beep Function. "Mike Williams" <Mike@WhiskyAndCoke.com> - 2012-01-07 20:53 +0000
                Re: The Beep Function. Gordon Levi <gordon@address.invalid> - 2012-01-08 17:27 +1100
                Re: The Beep Function. "Mike Williams" <Mike@WhiskyAndCoke.com> - 2012-01-08 09:49 +0000
                Re: The Beep Function. "blank" <blank@blankety.blank.com> - 2012-01-08 08:00 +1100
                Re: The Beep Function. "Mike Williams" <Mike@WhiskyAndCoke.com> - 2012-01-07 22:43 +0000
      Re: The Beep Function. "Mike Williams" <Mike@WhiskyAndCoke.com> - 2012-01-05 14:13 +0000
        Re: The Beep Function. Peter Nolan <peter.nolan40@gmail.com> - 2012-01-05 08:26 -0800
        Re: The Beep Function. Peter Nolan <peter.nolan40@gmail.com> - 2012-01-05 08:04 -0800
        Re: The Beep Function. Peter Nolan <peter.nolan40@gmail.com> - 2012-01-07 04:41 -0800
          Re: The Beep Function. "Mike Williams" <Mike@WhiskyAndCoke.com> - 2012-01-08 11:19 +0000
        Re: The Beep Function. Peter Nolan <peter.nolan40@gmail.com> - 2012-01-10 04:52 -0800
          Re: The Beep Function. "Thorsten Albers" <gudea@gmx.de> - 2012-01-10 13:01 +0000
          Re: The Beep Function. Jim Mack <no-uce-ube@mdxi.com> - 2012-01-10 11:44 -0500
            Re: The Beep Function. Peter Nolan <peter.nolan40@gmail.com> - 2012-01-11 05:58 -0800
          Re: The Beep Function. "Mike Williams" <Mike@WhiskyAndCoke.com> - 2012-01-10 17:19 +0000
            Re: The Beep Function. Peter Nolan <peter.nolan40@gmail.com> - 2012-01-11 05:54 -0800
              Re: The Beep Function. "DaveO" <djo@dial.pipex.com> - 2012-01-11 15:21 +0000
                Re: The Beep Function. Peter Nolan <peter.nolan40@gmail.com> - 2012-01-12 08:04 -0800
                Re: The Beep Function. "blank" <blank@blankety.blank.com> - 2012-01-13 12:40 +1100
                Re: The Beep Function. ralph <nt_consulting64@yahoo.net> - 2012-01-12 21:28 -0600
                Re: The Beep Function. "blank" <blank@blankety.blank.com> - 2012-01-13 15:34 +1100
                Re: The Beep Function. Peter Nolan <peter.nolan40@gmail.com> - 2012-01-13 05:25 -0800
                Re: The Beep Function. "blank" <blank@blankety.blank.com> - 2012-01-14 07:32 +1100
                Re: The Beep Function. "DaveO" <djo@dial.pipex.com> - 2012-01-13 11:06 +0000
                Re: The Beep Function. Peter Nolan <peter.nolan40@gmail.com> - 2012-01-13 05:48 -0800
                Re: The Beep Function. "DaveO" <djo@dial.pipex.com> - 2012-01-13 15:09 +0000
                Re: The Beep Function. Peter Nolan <peter.nolan40@gmail.com> - 2012-01-14 04:29 -0800
                Re: The Beep Function. Helmut_Meukel <Helmut_Meukel@bn-hof.invalid> - 2012-01-14 14:56 +0100
                Re: The Beep Function. ralph <nt_consulting64@yahoo.net> - 2012-01-14 10:24 -0600
                Re: The Beep Function. Helmut_Meukel <Helmut_Meukel@bn-hof.invalid> - 2012-01-14 18:51 +0100
                Re: The Beep Function. Peter Nolan <peter.nolan40@gmail.com> - 2012-01-15 03:39 -0800
                Re: The Beep Function. Schmidt <sss@online.de> - 2012-01-15 17:39 +0100
                Re: The Beep Function. Peter Nolan <peter.nolan40@gmail.com> - 2012-01-16 05:21 -0800
                Re: The Beep Function. "DaveO" <djo@dial.pipex.com> - 2012-01-16 14:39 +0000
                Re: The Beep Function. Peter Nolan <peter.nolan40@gmail.com> - 2012-01-17 04:13 -0800
                Re: The Beep Function. "DaveO" <djo@dial.pipex.com> - 2012-01-17 14:17 +0000
                Re: The Beep Function. Peter Nolan <peter.nolan40@gmail.com> - 2012-01-17 07:22 -0800
                Re: The Beep Function. "Henning" <computer_hero@coldmail.com> - 2012-01-17 17:47 +0100
                Re: The Beep Function. "DaveO" <djo@dial.pipex.com> - 2012-01-17 16:50 +0000
                Re: The Beep Function. "Henning" <computer_hero@coldmail.com> - 2012-01-17 18:22 +0100
                Re: The Beep Function. Peter Nolan <peter.nolan40@gmail.com> - 2012-01-18 05:26 -0800
                Re: The Beep Function. "DaveO" <djo@dial.pipex.com> - 2012-01-18 14:35 +0000
                Re: The Beep Function. Peter Nolan <peter.nolan40@gmail.com> - 2012-01-18 07:10 -0800
                Re: The Beep Function. ralph <nt_consulting64@yahoo.net> - 2012-01-18 10:38 -0600
                Re: The Beep Function. "blank" <blank@blankety.blank.com> - 2012-01-19 05:42 +1100
                Re: The Beep Function. "DaveO" <djo@dial.pipex.com> - 2012-01-19 11:33 +0000
                Re: The Beep Function. Peter Nolan <peter.nolan40@gmail.com> - 2012-01-21 03:16 -0800
                Re: The Beep Function. Peter Nolan <peter.nolan40@gmail.com> - 2012-01-19 05:17 -0800
                Re: The Beep Function. "blank" <blank@blankety.blank.com> - 2012-01-20 05:17 +1100
                Re: The Beep Function. Peter Nolan <peter.nolan40@gmail.com> - 2012-01-20 03:54 -0800
                Re: The Beep Function. Jason Keats <jkeats@melbpcDeleteThis.org.au> - 2012-01-20 23:40 +1100
                Re: The Beep Function. Peter Nolan <peter.nolan40@gmail.com> - 2012-01-21 03:20 -0800
                Re: The Beep Function. "blank" <blank@blankety.blank.com> - 2012-01-21 15:20 +1100
                Re: The Beep Function. Peter Nolan <peter.nolan40@gmail.com> - 2012-01-21 03:23 -0800
                Re: The Beep Function. "blank" <blank@blankety.blank.com> - 2012-01-20 05:11 +1100
                Re: The Beep Function. Schmidt <sss@online.de> - 2012-01-17 18:58 +0100
                Re: The Beep Function. Helmut_Meukel <Helmut_Meukel@bn-hof.invalid> - 2012-01-17 23:13 +0100
                Re: The Beep Function. "DaveO" <djo@dial.pipex.com> - 2012-01-18 09:12 +0000
                Re: The Beep Function. "DaveO" <djo@dial.pipex.com> - 2012-01-18 09:22 +0000
                Re: The Beep Function. ralph <nt_consulting64@yahoo.net> - 2012-01-18 05:39 -0600
                Re: The Beep Function. Helmut_Meukel <Helmut_Meukel@bn-hof.invalid> - 2012-01-18 13:32 +0100
                Re: The Beep Function. ralph <nt_consulting64@yahoo.net> - 2012-01-15 13:30 -0600
                Re: The Beep Function. "blank" <blank@blankety.blank.com> - 2012-01-16 06:59 +1100
                Re: The Beep Function. "blank" <blank@blankety.blank.com> - 2012-01-16 06:55 +1100
                Re: The Beep Function. Peter Nolan <peter.nolan40@gmail.com> - 2012-01-16 06:06 -0800
                Re: The Beep Function. "Mike Williams" <Mike@WhiskyAndCoke.com> - 2012-01-13 22:34 +0000
                Re: The Beep Function. "blank" <blank@blankety.blank.com> - 2012-01-14 19:50 +1100
                Re: The Beep Function. Peter Nolan <peter.nolan40@gmail.com> - 2012-01-14 05:10 -0800
                Re: The Beep Function. Peter Nolan <peter.nolan40@gmail.com> - 2012-01-14 06:16 -0800
  Re: The Beep Function. "Henning" <computer_hero@coldmail.com> - 2012-01-19 20:25 +0100
    Re: The Beep Function. Peter Nolan <peter.nolan40@gmail.com> - 2012-01-20 03:56 -0800

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