echogarden
Version:
An easy-to-use speech toolset. Includes tools for synthesis, recognition, alignment, speech translation, language detection, source separation and more.
114 lines • 5.62 kB
JavaScript
import { decodeAscii } from './Ascii.js';
export function encodeBase64(inputBytes, paddingCharacter = '=', charCodeMap) {
const asciiBuffer = encodeBase64AsAsciiBuffer(inputBytes, undefined, paddingCharacter, charCodeMap);
return decodeAscii(asciiBuffer);
}
export function encodeBase64AsAsciiBuffer(inputBytes, asciiBuffer, paddingCharacter = '=', charCodeMap) {
if (!inputBytes || inputBytes.length == 0) {
return new Uint8Array(0);
}
let paddingCharCode;
if (paddingCharacter == null) {
paddingCharCode = -1;
}
else if (paddingCharacter.length !== 1) {
throw new Error(`A padding character can only be a single character`);
}
else {
paddingCharCode = paddingCharacter.charCodeAt(0);
}
if (!charCodeMap) {
charCodeMap = defaultBase64CharCodeMap;
}
let charCodes;
if (asciiBuffer) {
charCodes = asciiBuffer;
}
else {
charCodes = new Uint8Array(Math.floor((inputBytes.length * 4 / 3) + 4));
}
const inputBytesLength = inputBytes.length;
let writeOffset = 0;
let readOffset = 0;
while (readOffset <= inputBytesLength - 3) {
const uint24 = inputBytes[readOffset++] << 16 |
inputBytes[readOffset++] << 8 |
inputBytes[readOffset++];
charCodes[writeOffset++] = charCodeMap[(uint24 >>> 18) & 63];
charCodes[writeOffset++] = charCodeMap[(uint24 >>> 12) & 63];
charCodes[writeOffset++] = charCodeMap[(uint24 >>> 6) & 63];
charCodes[writeOffset++] = charCodeMap[(uint24) & 63];
}
if (readOffset === inputBytesLength - 2) {
// If two bytes are left, output 3 encoded characters and one padding character
const uint24 = inputBytes[readOffset++] << 16 |
inputBytes[readOffset++] << 8;
charCodes[writeOffset++] = charCodeMap[(uint24 >>> 18) & 63];
charCodes[writeOffset++] = charCodeMap[(uint24 >>> 12) & 63];
charCodes[writeOffset++] = charCodeMap[(uint24 >>> 6) & 63];
if (paddingCharCode >= 0) {
charCodes[writeOffset++] = paddingCharCode;
}
}
else if (readOffset === inputBytesLength - 1) {
// Arrived at last byte at a position that did not complete a full 3 byte set
const uint24 = inputBytes[readOffset++] << 16;
charCodes[writeOffset++] = charCodeMap[(uint24 >>> 18) & 63];
charCodes[writeOffset++] = charCodeMap[(uint24 >>> 12) & 63];
if (paddingCharCode >= 0) {
charCodes[writeOffset++] = paddingCharCode;
charCodes[writeOffset++] = paddingCharCode;
}
}
return charCodes.subarray(0, writeOffset);
}
export function decodeBase64(base64String, outputBuffer, paddingCharacter = '=', reverseCharCodeMap) {
if (!base64String || base64String.length === 0) {
return new Uint8Array(0);
}
if (!paddingCharacter || paddingCharacter.length !== 1) {
throw new Error(`A valid padding character must be provided for Base 64 decoding`);
}
// Add padding if omitted
const lengthModulo4 = base64String.length % 4;
if (lengthModulo4 === 1) {
throw new Error(`Invalid Base64 string: length % 4 == 1`);
}
else if (lengthModulo4 === 2) {
base64String += paddingCharacter;
base64String += paddingCharacter;
}
else if (lengthModulo4 === 3) {
base64String += paddingCharacter;
}
if (!reverseCharCodeMap) {
reverseCharCodeMap = defaultBase64ReverseCharCodeMap;
}
if (!outputBuffer) {
const capacity = (base64String.length / 4) * 3;
outputBuffer = new Uint8Array(capacity);
}
const stringLength = base64String.length;
let readOffset = 0;
let writeOffset = 0;
while (readOffset < stringLength) {
const uint24 = (reverseCharCodeMap[base64String.charCodeAt(readOffset++)] << 18) |
(reverseCharCodeMap[base64String.charCodeAt(readOffset++)] << 12) |
(reverseCharCodeMap[base64String.charCodeAt(readOffset++)] << 6) |
(reverseCharCodeMap[base64String.charCodeAt(readOffset++)]);
outputBuffer[writeOffset++] = (uint24 >>> 16) & 255;
outputBuffer[writeOffset++] = (uint24 >>> 8) & 255;
outputBuffer[writeOffset++] = (uint24) & 255;
}
// Remove 1 or 2 last bytes if padding characters were added to the string
if (base64String[stringLength - 1] === paddingCharacter) {
writeOffset--;
}
if (base64String[stringLength - 2] === paddingCharacter) {
writeOffset--;
}
return outputBuffer.subarray(0, writeOffset);
}
export const defaultBase64CharCodeMap = new Uint8Array([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, 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, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 43, 47]);
export const defaultBase64ReverseCharCodeMap = new Uint8Array([255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 62, 255, 255, 255, 63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 255, 255, 255, 0, 255, 255, 255, 0, 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, 255, 255, 255, 255, 255, 255, 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, 255, 255, 255, 255]);
//# sourceMappingURL=Base64.js.map