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Hi Jim,
Hi Jim,
Sorry for the late response. I don't think anyone else has taken a look at this yet.
The manual says that ktime0 should always be zero, you've given it a value of 1 so perhaps that is the first problem. You also haven't given the opcode a correct number of arguments. It should have 7, 10, 13 etc. Qutecsound won't crash if you follow these requirements.
The following envelope rises from zero to 1 with concave shape over 5 seconds and decays from 1 to zero over the next 5 seconds also with a concave shape
k_env1 looptseg 0.1,0, 0,0,4, 0.5,1,-4, 0.5,0
and is roughly equivalent to
k_env1 expseg 0.0001,5,1,5,0.0001
for one cycle.
Note that a type value of 4 results in a concave shape when a segment is rising but convex when falling so to achieve a concave shape on the descending segement of the envelope a value of -4 was required.
These are my findings after rendering some enveloped sine waves in Audacity. Please correct me anybody if I'm wrong somewhere.
Hope this helps,
Iain
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> Date: Sun, 12 Sep 2010 23:10:46 -0700
> From: midiguru23@sbcglobal.net
> To: csound@lists.bath.ac.uk
> Subject: [Csnd] looptseg difficulties
>
>
> Looks like a cool new opcode ... but when I try to use it, QuteCsound
> crashes. Here's the line in my code:
>
> k_env1 looptseg 0.1, 0, 1, 0, 0, 2, 2, 1, 5 ; , 0, 1
>
> This crashes well before the end of the first iteration of the envelope
> (about five seconds after the instrument starts). If I uncomment those last
> two numbers, it crashes immediately. Trying various values in the second
> triplet of parameters doesn't prevent the crash.
>
> The manual is not entirely clear on the usage of this opcode. For starters,
> the type and value parameters switch places after the first trio of
> parameters:
>
> ksig looptseg kfreq, ktrig, ktime0, kvalue0, ktype, [, ktime1] [,ktype1] [,
> kvalue1] \
>
> Should it be time/value/type throughout, or is the reversal intentional?
>
> Second, it's unclear whether the type parameter is the type for the curve
> that follows the corresponding envelope point or for the curve that precedes
> it. This would make a difference.
>
> Third, the number of parameters in the example given in the manual is
> difficult to understand. After two triplets, it ends with a single
> parameter. But that would be a time that has no value. Should we assume that
> the value at point N is the same as the value at point 0? If so, the
> parameter list should always end with a singleton (preceded by 1 or more
> triplets). Is that correct?
>
> Fourth, I don't understand this explanation: "ktype0...ktypeN -- shape of
> the envelope. If the value is 0 then the shap eis linear; otherwise it is an
> concave exponential (positive type) or a convex exponential (negative
> type)." This sentence doesn't actually state what values should be used for
> the type parameter to produce a positive or negative curve.
>
> Can anyone clear up my perplexities? Thanks in advance!
>
> --Jim Aikin
>
>
> --
> View this message in context: http://csound.1045644.n5.nabble.com/looptseg-difficulties-tp2837329p2837329.html
> Sent from the Csound - General mailing list archive at Nabble.com.
>
>
> Send bugs reports to the Sourceforge bug tracker
> https://sourceforge.net/tracker/?group_id=81968&atid=564599
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>
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