1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
|
<HTML>
<HEAD>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1">
<META NAME="GENERATOR" CONTENT="Mozilla/4.04 [en] (X11; I; IRIX 6.3 IP32) [Netscape]">
<TITLE>Tutorial 3 - Building CECILIA modules</TITLE>
</HEAD>
<BODY>
<CENTER> </CENTER>
<CENTER><TABLE COLS=3 WIDTH="100%" NOSAVE >
<TR ALIGN=CENTER VALIGN=CENTER NOSAVE>
<TD ALIGN=LEFT VALIGN=TOP NOSAVE><B><A HREF="tut2.html"><--</A></B></TD>
<TD ALIGN=CENTER VALIGN=CENTER NOSAVE><A HREF="index.html"><IMG SRC="help.gif" ></A></TD>
<TD ALIGN=RIGHT VALIGN=TOP NOSAVE><B><FONT COLOR="#000000"><A HREF="soundwin.html">--></A></FONT></B></TD>
</TR>
</TABLE></CENTER>
<CENTER>
<H2>
<B>TUTORIAL 3 : BUILDING CECILIA MODULES</B></H2></CENTER>
<CENTER><A HREF="#Getting ready">Building a simple CECILIA sound-processing
module</A></CENTER>
<CENTER><A HREF="#Building the interface">Buliding the interface</A></CENTER>
<CENTER><A HREF="#Opening">Making the orchestra and score</A></CENTER>
<CENTER> </CENTER>
<CENTER>
<HR></CENTER>
<UL>
<LI>
<A NAME="Getting ready"></A><B>Building a simple CECILIA sound-processing
module. <FONT SIZE=-2><A HREF="#">top</A></FONT></B></LI>
<P>This tutorial assumes that the user is familiar with Csound programming.
<P>We will build a small module for filtering sounds. This module will
feature a choice of low-pass, hi-pass, bandpass and band-reject filter,
along with a time-function to control the cut-off and/or center frequency.
We will also offer a post filter gain slider, a selector for choosing the
soundfile to process and an automatic balance switch to reestablish power
to the filtered sound.
<P>Normally, we would first build the orchestra in Csound and then add
the interface, but since we already know what we want to do, we will first
build the interface.</UL>
<HR WIDTH="100%">
<UL>
<LI>
<A NAME="Building the interface"></A><B>Building the interface. <FONT SIZE=-2><A HREF="#">top</A></FONT></B></LI>
<P>We will therefor need to define the following interface objects:
<BR>
<OL>
<LI>
a <A HREF="cec_file.html">selector</A> to choose to sound to be processed</LI>
<LI>
a <A HREF="cec_grap.html">graph</A> for the time varying cut-off frequency
of the filter.</LI>
<LI>
a <A HREF="cec_grap.html">graph</A> for the bandwidth of the filter (for
band-pass and band-reject variants).</LI>
<LI>
a <A HREF="cec_popu.html">popup</A> to select the type of filtering.</LI>
<LI>
a <A HREF="cec_rsli.html">slider</A> for the output gain.</LI>
<LI>
a <A HREF="cec_togg.html">toggle</A> for reesetablishing the level of the
sound.</LI>
<BR> </OL>
We will be using Csound's <A HREF="../csman/Modifier/butterhp.html">Butterworth</A>
filters to do the filtering. To control the switching between different
kinds of filtering, we will use Csound's <A HREF="../csman/Syntax/igoto.html"><B>if
</B>/<B> goto</B></A><B> </B>structure.
<BR>
<UL>
<LI>
Under the <B>File</B> menu in the Main window, select <B>New...</B> and
then <B>Module...</B></LI>
<BR>
<LI>
Open the <B>tk_interface </B>editor pane by clicking on its button or choosing
it in the <B>Sections</B> menu.</LI>
<BR>
<LI>
Enter the first graph definition by typing this line:</LI>
<PRE><TT>cgraph freqc -unit Hz -label "Cut-off Frequency" -rel log -min 50 -max 20000 -init 2500</TT></PRE>
</UL>
<UL>
<LI>
Enter the second graph by doing Button-3 or Command-Click in the tk_interface
pane to bring up the inserter, Choose <B>graph freq </B>under the <B>Graphs</B>
cascade. The following pre-formatted line is inserted:</LI>
<PRE>cgraph freq -unit x -rel lo -min 20 -max 15000 -init 500</PRE>
But we will change the parameter range to -min .001, max 1 and init to
0.1 because this function will be used as a multiplier for the center frequency
(freqc) in the orchestra to give us the bandwidth of the filter. We also
change -rel log to -rel lin for a linear function. While we are here, let's
give it a label of "Bandwidth".</UL>
<UL>
<LI>
Enter the fileselector by using the same inserter method and choosing the
standard filein under <B>Filein.</B></LI>
<BR>
<LI>
Enter the toggle. Change the name to "select" and give the label "Balance
with Input".</LI>
<BR>
<LI>
Enter the slider with the inserter. Choose <B>slider10</B> under <B>Sliders.</B>
Change the name to "gain" and give a label "Post-Filter Gain". Change to
init value to 1.</LI>
<BR>
<LI>
Enter the popup with he inserter. Change the name to "type" , the label
to "Select Filter Type" and give this list for value: "lo-pass hi-pass
band-pass band-reject".</LI>
<BR> </UL>
The contents of the tk_interface pane should now read as:
<PRE>cfilein name -label "Sound to process"
cgraph freqc -label "Cut-off Frequency" -rel log -min 50 -max 20000 -init 2500
cgraph freq -label "Center Frequency" -rel lin -min .001 -max 1 -init 0.1
cslider data10 -label "Post-Filter Gain" -res .1 -min 0 -max 10 -init 1
ctoggle gain -label "Balance with Input" -init 0
cpopup type -label "Select Filter Type" -value "lo-pass hi-pass band-pass band-reject"</PRE>
Select <B>Save module as... </B>under the<B> File </B>menu, and give the
new module a name (TestFilters.cec is good). If all is well, the new module
will pop open with a grapher window and the Main window will enlarge to
include a file selector. CECILIA attempts to warn you on interface definition
errors. Check the interface carefully to make sure all the parameters and
objects are present and in the correct ranges.
<P>
<HR WIDTH="100%">
<BR>
<LI>
<A NAME="Opening"></A><B>Making the orchestra and the score. <FONT SIZE=-2><A HREF="#">top</A></FONT></B></LI>
<BR>
<UL>
<LI>
Open the stereo pane in the CECILIA editor.</LI>
<BR>
<LI>
Enter the following text in the pane:</LI>
</UL>
<UL><B><TT><FONT COLOR="#FF0000"> instr 1</FONT></TT></B>
<P><TT>a1,a2 <B><FONT COLOR="#000099">soundin</FONT></B> "[name]",
[offname] <B><FONT COLOR="#993399">; name from fileselector</FONT></B></TT>
<BR><B><TT><FONT COLOR="#993399">
; and offset substituted here</FONT></TT></B>
<P><TT>if gktype != 0 goto hp
<B><FONT COLOR="#993399">; using if / goto and the value</FONT></B></TT>
<BR><TT>ag <B><FONT COLOR="#000099">butterlp</FONT></B>
a1, gkfreqc <B><FONT COLOR="#993399">;
of the "type" popup to select</FONT></B></TT>
<BR><TT>ad <B><FONT COLOR="#000099">butterlp</FONT></B>
a2, gkfreqc <B><FONT COLOR="#993399">;
the correct kind of filter</FONT></B></TT>
<BR><TT>goto bal</TT>
<P><B><TT><FONT COLOR="#006600">hp:</FONT></TT></B>
<BR><TT>if gktype != 1 goto bp
<B><FONT COLOR="#993399">; the freqc graph controls the</FONT></B></TT>
<BR><TT>ag <B><FONT COLOR="#000099">butterhp</FONT></B>
a1, gkfreqc <FONT COLOR="#993399">;
<B>cut-off frequency</B></FONT></TT>
<BR><TT>ad <B><FONT COLOR="#000099">butterhp</FONT></B>
a2, gkfreqc</TT>
<BR><TT>goto bal</TT>
<P><B><TT><FONT COLOR="#006600">bp:</FONT></TT></B>
<BR><TT>if gktype != 2 goto br
<B><FONT COLOR="#993399">; the freq graph controls the</FONT></B></TT>
<BR><TT>ag <B><FONT COLOR="#000099">butterbp</FONT></B>
a1, gkfreqc, gkfreq*gkfreqc <B><FONT COLOR="#993399">;bandwidth</FONT></B></TT>
<BR><TT>ad <B><FONT COLOR="#000099">butterbp</FONT></B>
a2, gkfreqc, gkfreq*gkfreqc</TT>
<BR><TT>goto bal</TT>
<P><B><TT><FONT COLOR="#006600">br:</FONT></TT></B>
<BR><TT>ag <B><FONT COLOR="#000099">butterbr
</FONT></B>a1, gkfreqc, gkfreq*gkfreqc</TT>
<BR><TT>ad <B><FONT COLOR="#000099">butterbr
</FONT></B>a2, gkfreqc, gkfreq*gkfreqc</TT>
<P><B><TT><FONT COLOR="#006600">bal:</FONT></TT></B>
<BR><TT>if gkgain == 0 goto nobal
<B><FONT COLOR="#993399">; gkgain toggle decides to</FONT></B></TT>
<BR><TT>ag <B><FONT COLOR="#000099">balance
</FONT></B>ag, a1
<B><FONT COLOR="#993399">; balance or not</FONT></B></TT>
<BR><TT>ad <B><FONT COLOR="#000099">balance
</FONT></B>ad, a2</TT>
<P><B><TT><FONT COLOR="#006600">nobal:</FONT></TT></B>
<BR><TT><B><FONT COLOR="#000099">outs</FONT></B> ag*gkdata10, ag*gkdata10
<B><FONT COLOR="#993399">; the data10 slider controls</FONT></B></TT>
<BR><B><TT><FONT COLOR="#993399">
; the final gain</FONT></TT></B>
<P><B><TT><FONT COLOR="#FF0000"> endin</FONT></TT></B></UL>
<BR>
<UL>
<LI>
Enter the score in the score editor pane. In fact, the only score that
we will need here is the <B>#min</B> keyword. Since the only note we want
is on instrument 1 and we do not need to pass it any parameter. The duration
of the note will always be the duration of the soundfile. This is a case
where the #min score is perfect. Make sure you study the other <A HREF="score.html">types
of scores </A>available in CECILIA. Studying the BuiltIn CECILIA
modules is a good way to develop an understanding for the powerful possibilities
of CECILIA score pre-processing.</LI>
<BR>
<LI>
Save the module, choose a sound with the file selector, define time-profiles
with the graphs and press <B>Play</B>!</LI>
<BR>
<LI>
Studying CECILIA's Builtin modules is highly recommended!</LI>
<BR> </UL>
</UL>
<HR WIDTH="100%">
<UL> </UL>
<UL> </UL>
</BODY>
</HTML>
|
