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<div class="elementToProof" style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Hi,</div>
<div class="elementToProof" style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Yes. Snd's make-square-wave works great. </div>
<div class="elementToProof" style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
I took another look at my code and figured out the problem was not reading from make-sampler, but my trying to get the maxval of the sampler's output to see what was going wrong.</div>
<div class="elementToProof" style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<br>
</div>
<div class="elementToProof" style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
I was using (set! maxval (float-vector-max (float-vector-abs! im))) and didn't realize float-vector-abs! was setting all the values to absolute value. I thought it was just getting the abs value. So for a square wave that's deadly.</div>
<div class="elementToProof" style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<br>
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<div class="elementToProof" style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
My fault.</div>
<div class="elementToProof" style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Thank you,</div>
<div class="elementToProof" style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Jim<br>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> cmdist-bounces@ccrma.Stanford.EDU <cmdist-bounces@ccrma.Stanford.EDU> on behalf of cmdist-request@ccrma.Stanford.EDU <cmdist-request@ccrma.Stanford.EDU><br>
<b>Sent:</b> Thursday, December 7, 2023 10:00 AM<br>
<b>To:</b> cmdist@ccrma.Stanford.EDU <cmdist@ccrma.Stanford.EDU><br>
<b>Subject:</b> Cmdist Digest, Vol 187, Issue 1</font>
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Today's Topics:<br>
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1. make-sampler vs. open (James Hearon)<br>
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Message: 1<br>
Date: Thu, 7 Dec 2023 18:12:56 +0000<br>
From: James Hearon <j_hearon@hotmail.com><br>
To: "cmdist@ccrma.Stanford.EDU" <cmdist@ccrma.Stanford.EDU><br>
Subject: [CM] make-sampler vs. open<br>
Message-ID:<br>
<SN7PR07MB9651B77F7DC22E6F046B1521E58BA@SN7PR07MB9651.namprd07.prod.outlook.com><br>
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Hi,<br>
I was trying to use make-sampler, but having a problem opening (read-sample) a non-bandlimited square wav effectively. Snd's Open menu function works fine, but the make-sampler approach gives a max'd out flat line which seems like it might be an aliasing problem?
I tried low-pass filtering with make-sample without much success.<br>
<br>
Instead I was tweaking this code below from spectrum as an fft filter for file based bandlimiting. Reason being most of what I was doing is outside the editor, or file-based manipulation before the sound gets opened in the editor. The result is better than
before but I'm still not seeing anything resembling a square wav yet with make-sampler and read-sample. I also tried some peak limiting on amplitudes, but still no joy.<br>
<br>
I'm wondering what might be the difference with Snd's file Open and why it works so well vs. the lower level approach of make-sampler, and read-sample, or what might be a better way to approach those pesky non-bandlimited snds?<br>
<br>
(let* ((len (mus-sound-framples "oboe.snd"))<br>
(fsize (expt 2 (ceiling (log len 2))))<br>
(rdata (make-float-vector fsize))<br>
(idata (make-float-vector fsize)))<br>
(file->array "oboe.snd" 0 0 len rdata)<br>
(mus-fft rdata idata fsize 1)<br>
(let ((fsize2 (/ fsize 2))<br>
(cutoff (round (/ fsize 10))))<br>
(do ((i cutoff (+ i 1))<br>
(j (- fsize 1) (- j 1)))<br>
((= i fsize2))<br>
(set! (rdata i) 0.0)<br>
(set! (idata i) 0.0)<br>
(set! (rdata j) 0.0)<br>
(set! (idata j) 0.0)))<br>
(mus-fft rdata idata fsize -1)<br>
(array->file "test.snd"<br>
(float-vector-scale! rdata (/ 1.0 fsize))<br>
len<br>
(srate "oboe.snd")<br>
1)<br>
(let ((previous-case (find-sound "test.snd")))<br>
(if (sound? previous-case)<br>
(close-sound previous-case)))<br>
(open-sound "test.snd"))<br>
<br>
Regards,<br>
Jim<br>
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