Passed
Push — master ( 1769fa...d9ce30 )
by Rafael S.
03:30
created

dw-channel-mask.js ➔ dwChannelMask   B

Complexity

Conditions 6

Size

Total Lines 21
Code Lines 13

Duplication

Lines 0
Ratio 0 %

Importance

Changes 0
Metric Value
eloc 13
dl 0
loc 21
rs 8.6666
c 0
b 0
f 0
cc 6
1
/*
2
 * Copyright (c) 2017-2019 Rafael da Silva Rocha.
3
 *
4
 * Permission is hereby granted, free of charge, to any person obtaining
5
 * a copy of this software and associated documentation files (the
6
 * "Software"), to deal in the Software without restriction, including
7
 * without limitation the rights to use, copy, modify, merge, publish,
8
 * distribute, sublicense, and/or sell copies of the Software, and to
9
 * permit persons to whom the Software is furnished to do so, subject to
10
 * the following conditions:
11
 *
12
 * The above copyright notice and this permission notice shall be
13
 * included in all copies or substantial portions of the Software.
14
 *
15
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
19
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
20
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
21
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
22
 *
23
 */
24
25
/**
26
 * @fileoverview The dwChannelMask function.
27
 * @see https://github.com/rochars/wavefile
28
 */
29
30
/**
31
 * Return the value for dwChannelMask according to the number of channels.
32
 * @param {number} numChannels the number of channels.
33
 * @return {number} the dwChannelMask value.
34
 */
35
export default function dwChannelMask(numChannels) {
36
  /** @type {number} */
37
  let mask = 0;
38
  // mono = FC
39
  if (numChannels === 1) {
40
    mask = 0x4;
41
  // stereo = FL, FR
42
  } else if (numChannels === 2) {
43
    mask = 0x3;
44
  // quad = FL, FR, BL, BR
45
  } else if (numChannels === 4) {
46
    mask = 0x33;
47
  // 5.1 = FL, FR, FC, LF, BL, BR
48
  } else if (numChannels === 6) {
49
    mask = 0x3F;
50
  // 7.1 = FL, FR, FC, LF, BL, BR, SL, SR
51
  } else if (numChannels === 8) {
52
    mask = 0x63F;
53
  }
54
  return mask;
55
}
56