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
|
<?xml version="1.0"?>
<!DOCTYPE ladspa SYSTEM "ladspa-swh.dtd">
<?xml-stylesheet href="ladspa.css" type="text/css"?>
<ladspa>
<global>
<meta name="maker" value="Steve Harris <steve@plugin.org.uk>"/>
<meta name="copyright" value="GPL"/>
<meta name="properties" value="HARD_RT_CAPABLE"/>
<code><![CDATA[
#include <stdlib.h>
#include <math.h>
#include "ladspa-util.h"
/* Beware of dependcies if you change this */
#define DELAY_SIZE 8192
]]></code>
</global>
<plugin label="amPitchshift" id="1433" class="PitchPlugin">
<name>AM pitchshifter</name>
<p>This plugin works by running a single write pointer (monotonic) and two read pointers (pitchscaled) over a ringbuffer.</p>
<p>The output is faded between the two readpointers according to the sine of the distance from the write pointer. The design is based on the mechanism of a mechanical pitchshifter I saw in the Gemeentemuseum in Den Haag, though I'm sure it is a common enough algorithm.</p>
<callback event="instantiate"><![CDATA[
delay = calloc(DELAY_SIZE, sizeof(LADSPA_Data));
rptr.all = 0;
wptr = 0;
last_size = -1;
delay_mask = 0xFF;
delay_ofs = 0x80;
last_gain = 0.5f;
count = 0;
last_inc = 0.0f;
]]></callback>
<callback event="cleanup"><![CDATA[
free(plugin_data->delay);
]]></callback>
<callback event="run"><![CDATA[
unsigned long pos;
fixp16 om;
float gain = last_gain, gain_inc = last_inc;
unsigned int i;
om.all = f_round(pitch * 65536.0f);
if (size != last_size) {
int size_tmp = f_round(size);
if (size_tmp > 7) {
size_tmp = 5;
} else if (size_tmp < 1) {
size_tmp = 1;
}
plugin_data->last_size = size;
/* Calculate the ringbuf parameters, the magick constants will need
* to be changed if you change DELAY_SIZE */
delay_mask = (1 << (size_tmp + 6)) - 1;
delay_ofs = 1 << (size_tmp + 5);
}
for (pos = 0; pos < sample_count; pos++) {
float out = 0.0f;
if (count++ > 14) {
float tmp;
count = 0;
tmp = 0.5f * (float)((rptr.part.in - wptr + delay_ofs/2) &
delay_mask) / (float)delay_ofs;
tmp = sinf(M_PI * 2.0f * tmp) * 0.5f + 0.5f;
gain_inc = (tmp - gain) / 15.0f;
}
gain += gain_inc;
delay[wptr] = input[pos];
/* Add contributions from the two readpointers, scaled by thier
* distance from the write pointer */
i = rptr.part.in;
out += cube_interp((float)rptr.part.fr * 0.0000152587f,
delay[(i - 1) & delay_mask], delay[i],
delay[(i + 1) & delay_mask],
delay[(i + 2) & delay_mask]) * (1.0f - gain);
i += delay_ofs;
out += cube_interp((float)rptr.part.fr * 0.0000152587f,
delay[(i - 1) & delay_mask], delay[i & delay_mask],
delay[(i + 1) & delay_mask],
delay[(i + 2) & delay_mask]) * gain;
buffer_write(output[pos], out);
/* Increment ringbuffer pointers */
wptr = (wptr + 1) & delay_mask;
rptr.all += om.all;
rptr.part.in &= delay_mask;
}
plugin_data->rptr.all = rptr.all;
plugin_data->wptr = wptr;
plugin_data->delay_mask = delay_mask;
plugin_data->delay_ofs = delay_ofs;
plugin_data->last_gain = gain;
plugin_data->count = count;
plugin_data->last_inc = gain_inc;
*(plugin_data->latency) = delay_ofs/2;
]]></callback>
<port label="pitch" dir="input" type="control" hint="logarithmic,default_1">
<name>Pitch shift</name>
<p>The multiple of the output pitch, eg. 2.0 will increase the pitch by one octave.</p>
<range min="0.25" max="4.0"/>
</port>
<port label="size" dir="input" type="control" hint="integer,default_middle">
<name>Buffer size</name>
<p>The order of magnitude of the buffer size. Small buffers will sound fluttery, large buffers will have flangy sounding echos.</p>
<p>I recommend a buffer size of 3 for a reasonable compromise, with wideband material at around 48KHz. For drums you might have to lower it, and for voiced background noises it can go higher.</p>
<range min="1" max="7"/>
</port>
<port label="input" dir="input" type="audio">
<name>Input</name>
</port>
<port label="output" dir="output" type="audio">
<name>Output</name>
</port>
<port label="latency" dir="output" type="control">
<name>latency</name>
</port>
<instance-data label="delay" type="LADSPA_Data *" />
<instance-data label="rptr" type="fixp16" />
<instance-data label="wptr" type="unsigned int" />
<instance-data label="last_size" type="int" />
<instance-data label="delay_mask" type="unsigned int" />
<instance-data label="delay_ofs" type="unsigned int" />
<instance-data label="last_gain" type="float" />
<instance-data label="last_inc" type="float" />
<instance-data label="count" type="unsigned int" />
</plugin>
</ladspa>
|
