C07.envelope.follower.pd 4.47 KB
Newer Older
1
#N canvas 388 27 448 603 10;
2
#X text 19 123 Envelope followers are frequently used to detect attacks
Miller Puckette's avatar
Miller Puckette committed
3 4 5
and periods of silence. (There are fancier attack detectors out there
\, though.) Here is a simple threshold-based attack and rest detector.
;
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
#X obj 102 267 dbtorms;
#X obj 23 263 osc~ 440;
#X obj 23 309 env~;
#X floatatom 78 299 0 0 0 0 - - -;
#X floatatom 102 244 0 0 0 0 - - -;
#X msg 342 286 \; pd dsp 1;
#X obj 110 350 t b f;
#X floatatom 110 373 0 0 0 0 - - -;
#X obj 116 418 pack;
#X obj 116 441 route 0 1;
#X obj 116 464 > 55;
#X obj 166 464 < 45;
#X obj 116 487 sel 1;
#X obj 166 487 sel 1;
#X msg 70 498 1;
#X msg 70 476 0;
#X obj 116 514 print attack;
#X obj 110 395 != 0;
#X obj 23 565 t b f;
#X floatatom 23 591 0 0 0 0 - - -;
#X obj 35 641 pack;
#X obj 35 664 route 0 1;
#X obj 35 700 sel 1;
#X msg 14 809 1;
#X msg 15 832 0;
#X obj 28 619 != 0;
#X obj 66 592 < 45;
#X obj 39 736 timer;
#X obj 121 665 sel 0;
#X obj 103 785 sel 0;
#X obj 53 785 sel 1;
#X obj 53 826 print rest;
#X obj 39 759 > 1000;
#X text 153 373 state -- 1 if waiting for low threshold \,;
#X text 190 388 0 if we've attained it and now want the;
#X text 193 404 high one.;
#X text 180 441 route the RMS value according to state;
#X text 209 466 if off \, 55 dB means attack. If on \, 45;
#X text 209 487 dB or less means state changes to off.;
#X text 123 329 ATTACK DETECTION;
#X text 33 546 REST DETECTION;
#X text 98 590 Here we always will test RMS against a low value;
#X text 123 607 but as before we route the result according to;
#X text 145 624 our state \, 1 if "resting" \, 0 if not.;
#X text 161 662 regardless of state \, when RMS isn't low;
#X text 183 677 reset the timer;
#X text 180 799 RMS isn't low enough.;
#X text 108 697 If we're not in rest \, and the RMS is low \,;
#X text 131 714 check elapsed time sinse RMS last wasn't low.;
#X text 101 757 If more than 1 second \, report a rest.;
#X text 148 781 If we're at rest \, pop out of it when;
#X text 19 176 Both detectors are state machines with two states \,
Miller Puckette's avatar
Miller Puckette committed
58 59 60
on and off. If on \, a test is run to determine whether to turn off
\, and vice versa. The tests are run at each output of the rms~ object.
;
61 62 63 64 65 66 67 68
#X text 109 290 note 3.01 dB difference between;
#X text 109 305 peak and RMS amplitudes.;
#X obj 342 263 loadbang;
#X obj 23 286 *~;
#X obj 1 1 cnv 15 445 20 empty \$0-pddp.cnv.header envelope_followers
20 10 1 18 -261139 -33289 0;
#X obj 407 2 pddp/pddplink http://puredata.info/dev/pddp -text pddp
;
69
#X text 19 37 The [env~] object reports the RMS signal level over the
70 71 72 73 74 75 76 77 78
last 256 samples (by default) or any other power of 2 that's at least
twice the block size. The analysis is done in an overlapped fashion
so that results appear every N/2 points if N is the analysis window
size. So the larger the window \, the stabler the result and the less
frequently it appears. Computation time doesn't depend heavily on N.
;
#X obj 1 870 cnv 15 445 20 empty \$0-pddp.cnv.footer empty 20 12 0
14 -233017 -33289 0;
#N canvas 44 246 494 284 META 0;
79 80 81 82 83
#X text 12 105 WEBSITE http://crca.ucsd.edu/~msp/;
#X text 12 85 AUTHOR Miller Puckette;
#X text 12 65 LIBRARY PDDP;
#X text 12 25 LICENSE SIBSD;
#X text 12 125 HELP_PATCH_AUTHORS Updated for release 0.37. Jonathan
84 85
Wilkes revised the patch to conform to the PDDP template for Pd version
0.42.;
86 87
#X text 12 45 DESCRIPTION envelope followers;
#X text 12 5 KEYWORDS signal tutorial;
88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104
#X restore 392 872 pd META;
#N canvas 13 202 428 190 References 0;
#X obj 1 1 cnv 15 425 20 empty \$0-pddp.cnv.subheading empty 3 12 0
14 -261139 -33289 0;
#X text 19 37 links:;
#X text 7 2 envelope follower- Related Help Documents;
#X restore 103 872 pd References;
#X obj 6 872 pddp/pddplink ../5.reference/pddp/help.pd -text help;
#X connect 1 0 56 1;
#X connect 2 0 56 0;
#X connect 3 0 4 0;
#X connect 3 0 7 0;
#X connect 3 0 19 0;
#X connect 5 0 1 0;
#X connect 7 0 8 0;
#X connect 7 1 9 1;
#X connect 8 0 18 0;
Miller Puckette's avatar
Miller Puckette committed
105
#X connect 9 0 10 0;
106 107 108 109
#X connect 10 0 11 0;
#X connect 10 1 12 0;
#X connect 11 0 13 0;
#X connect 12 0 14 0;
Miller Puckette's avatar
Miller Puckette committed
110
#X connect 13 0 15 0;
111
#X connect 13 0 17 0;
Miller Puckette's avatar
Miller Puckette committed
112
#X connect 14 0 16 0;
113 114 115 116 117 118
#X connect 15 0 8 0;
#X connect 16 0 8 0;
#X connect 18 0 9 0;
#X connect 19 0 20 0;
#X connect 19 1 27 0;
#X connect 20 0 26 0;
Miller Puckette's avatar
Miller Puckette committed
119
#X connect 21 0 22 0;
120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135
#X connect 22 0 23 0;
#X connect 22 1 30 0;
#X connect 23 0 28 1;
#X connect 24 0 20 0;
#X connect 25 0 20 0;
#X connect 26 0 21 0;
#X connect 27 0 21 1;
#X connect 27 0 29 0;
#X connect 28 0 33 0;
#X connect 29 0 28 0;
#X connect 30 0 25 0;
#X connect 31 0 24 0;
#X connect 31 0 32 0;
#X connect 33 0 31 0;
#X connect 55 0 6 0;
#X connect 56 0 3 0;