|
1
|
|
|
/** |
|
2
|
|
|
* bitdepth |
|
3
|
|
|
* Change the resolution of samples to and from 8, 11, 12, 16, 20, 24, 32, 48 & 64-bit. |
|
4
|
|
|
* Copyright (c) 2017-2018 Rafael da Silva Rocha. |
|
5
|
|
|
* https://github.com/rochars/bitdepth |
|
6
|
|
|
* |
|
7
|
|
|
*/ |
|
8
|
|
|
|
|
9
|
|
|
/** @private */ |
|
10
|
|
|
const f64f32_ = new Float32Array(1); |
|
11
|
|
|
|
|
12
|
|
|
/** |
|
13
|
|
|
* Change the bit depth of the data in a array. |
|
14
|
|
|
* The input array is modified in-place. |
|
15
|
|
|
* @param {!Array<number>} samples The samples. |
|
16
|
|
|
* @param {!string} original The original bit depth of the data. |
|
17
|
|
|
* One of "8" ... "53", "32f", "64" |
|
18
|
|
|
* @param {!string} target The desired bit depth for the data. |
|
19
|
|
|
* One of "8" ... "53", "32f", "64" |
|
20
|
|
|
*/ |
|
21
|
|
|
function toBitDepth(samples, original, target) { |
|
22
|
|
|
if (original != target) { |
|
23
|
|
|
validateBitDepth_(original); |
|
24
|
|
|
validateBitDepth_(target); |
|
25
|
|
|
let toFunction = getBitDepthFunction_(original, target); |
|
26
|
|
|
let options = { |
|
27
|
|
|
oldMin: Math.pow(2, parseInt(original, 10)) / 2, |
|
28
|
|
|
newMin: Math.pow(2, parseInt(target, 10)) / 2, |
|
29
|
|
|
oldMax: (Math.pow(2, parseInt(original, 10)) / 2) - 1, |
|
30
|
|
|
newMax: (Math.pow(2, parseInt(target, 10)) / 2) - 1, |
|
31
|
|
|
}; |
|
32
|
|
|
signed8Bit_(samples, original, false); |
|
33
|
|
|
for (let i=0; i<samples.length; i++) { |
|
34
|
|
|
samples[i] = toFunction(samples[i], options); |
|
35
|
|
|
} |
|
36
|
|
|
signed8Bit_(samples, target, true); |
|
37
|
|
|
} |
|
38
|
|
|
} |
|
39
|
|
|
|
|
40
|
|
|
/** |
|
41
|
|
|
* Sign or unsign 8-bit samples. |
|
42
|
|
|
* The input array is modified in-place. |
|
43
|
|
|
* @param {!Array<number>} samples The samples. |
|
44
|
|
|
* @param {!string} bitDepth The original bit depth of the data. |
|
45
|
|
|
* @param {!boolean} signed True if should sign the samples, false otherwise. |
|
46
|
|
|
*/ |
|
47
|
|
|
function signed8Bit_(samples, bitDepth, signed) { |
|
48
|
|
|
if (bitDepth == "8") { |
|
49
|
|
|
if (signed) { |
|
50
|
|
|
for (let i=0; i<samples.length; i++) { |
|
51
|
|
|
samples[i] += 128; |
|
52
|
|
|
} |
|
53
|
|
|
} else { |
|
54
|
|
|
for (let i=0; i<samples.length; i++) { |
|
55
|
|
|
samples[i] -= 128; |
|
56
|
|
|
} |
|
57
|
|
|
} |
|
58
|
|
|
} |
|
59
|
|
|
} |
|
60
|
|
|
|
|
61
|
|
|
/** |
|
62
|
|
|
* Change the bit depth from int to int. |
|
63
|
|
|
* @param {!number} sample The sample. |
|
64
|
|
|
* @param {!Object} args Data about the original and target bit depths. |
|
65
|
|
|
* @return {!number} |
|
66
|
|
|
* @private |
|
67
|
|
|
*/ |
|
68
|
|
|
function intToInt_(sample, args) { |
|
69
|
|
|
if (sample > 0) { |
|
70
|
|
|
sample = parseInt((sample / args.oldMax) * args.newMax, 10); |
|
71
|
|
|
} else { |
|
72
|
|
|
sample = parseInt((sample / args.oldMin) * args.newMin, 10); |
|
73
|
|
|
} |
|
74
|
|
|
return sample; |
|
75
|
|
|
} |
|
76
|
|
|
|
|
77
|
|
|
/** |
|
78
|
|
|
* Change the bit depth from float to int. |
|
79
|
|
|
* @param {!number} sample The sample. |
|
80
|
|
|
* @param {!Object} args Data about the original and target bit depths. |
|
81
|
|
|
* @return {!number} |
|
82
|
|
|
* @private |
|
83
|
|
|
*/ |
|
84
|
|
|
function floatToInt_(sample, args) { |
|
85
|
|
|
return parseInt( |
|
86
|
|
|
sample > 0 ? sample * args.newMax : sample * args.newMin, 10); |
|
87
|
|
|
} |
|
88
|
|
|
|
|
89
|
|
|
/** |
|
90
|
|
|
* Change the bit depth from int to float. |
|
91
|
|
|
* @param {!number} sample The sample. |
|
92
|
|
|
* @param {!Object} args Data about the original and target bit depths. |
|
93
|
|
|
* @return {!number} |
|
94
|
|
|
* @private |
|
95
|
|
|
*/ |
|
96
|
|
|
function intToFloat_(sample, args) { |
|
97
|
|
|
return sample > 0 ? sample / args.oldMax : sample / args.oldMin; |
|
98
|
|
|
} |
|
99
|
|
|
|
|
100
|
|
|
/** |
|
101
|
|
|
* Change the bit depth from float to float. |
|
102
|
|
|
* @param {!number} sample The sample. |
|
103
|
|
|
* @return {!number} |
|
104
|
|
|
* @private |
|
105
|
|
|
*/ |
|
106
|
|
|
function floatToFloat_(sample) { |
|
107
|
|
|
f64f32_[0] = sample; |
|
108
|
|
|
sample = f64f32_[0]; |
|
109
|
|
|
return sample; |
|
110
|
|
|
} |
|
111
|
|
|
|
|
112
|
|
|
/** |
|
113
|
|
|
* Get the function to change the bit depth of a sample. |
|
114
|
|
|
* @param {!string} original The original bit depth of the data. |
|
115
|
|
|
* One of "8" ... "53", "32f", "64" |
|
116
|
|
|
* @param {!string} target The new bit depth of the data. |
|
117
|
|
|
* One of "8" ... "53", "32f", "64" |
|
118
|
|
|
* @return {!Function} |
|
119
|
|
|
* @private |
|
120
|
|
|
*/ |
|
121
|
|
|
function getBitDepthFunction_(original, target) { |
|
122
|
|
|
if (["32f", "64"].includes(original)) { |
|
123
|
|
|
if (["32f", "64"].includes(target)) { |
|
124
|
|
|
return floatToFloat_; |
|
125
|
|
|
} else { |
|
|
|
|
|
|
126
|
|
|
return floatToInt_; |
|
127
|
|
|
} |
|
128
|
|
|
} else { |
|
|
|
|
|
|
129
|
|
|
if (["32f", "64"].includes(target)) { |
|
130
|
|
|
return intToFloat_; |
|
131
|
|
|
} else { |
|
|
|
|
|
|
132
|
|
|
return intToInt_; |
|
133
|
|
|
} |
|
134
|
|
|
} |
|
135
|
|
|
} |
|
136
|
|
|
|
|
137
|
|
|
/** |
|
138
|
|
|
* Validate the bit depth. |
|
139
|
|
|
* @param {!string} bitDepth The original bit depth. |
|
140
|
|
|
* Should be one of "8" ... "53", "32f" or "64". |
|
141
|
|
|
* @throws {Error} If any argument does not meet the criteria. |
|
142
|
|
|
* @return {!boolean} |
|
143
|
|
|
* @private |
|
144
|
|
|
*/ |
|
145
|
|
|
function validateBitDepth_(bitDepth) { |
|
146
|
|
|
if ((bitDepth != "32f" && bitDepth != "64") && |
|
147
|
|
|
(parseInt(bitDepth, 10) < "8" || parseInt(bitDepth, 10) > "53")) { |
|
148
|
|
|
throw new Error("Invalid bit depth."); |
|
149
|
|
|
} |
|
150
|
|
|
return true; |
|
151
|
|
|
} |
|
152
|
|
|
|
|
153
|
|
|
module.exports = toBitDepth; |
|
154
|
|
|
module.exports.toBitDepth = toBitDepth; |
|
155
|
|
|
|
rochars /
bitdepth
Loading history...