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84 lines
2.1 KiB
84 lines
2.1 KiB
4 years ago
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"use strict";
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Object.defineProperty(exports, "__esModule", {
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value: true
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});
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exports.findFourCC = void 0;
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var _byteHelpers = require("./byte-helpers.js");
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var CONSTANTS = {
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LIST: (0, _byteHelpers.toUint8)([0x4c, 0x49, 0x53, 0x54]),
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RIFF: (0, _byteHelpers.toUint8)([0x52, 0x49, 0x46, 0x46]),
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WAVE: (0, _byteHelpers.toUint8)([0x57, 0x41, 0x56, 0x45])
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};
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var normalizePath = function normalizePath(path) {
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if (typeof path === 'string') {
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return (0, _byteHelpers.stringToBytes)(path);
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}
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if (typeof path === 'number') {
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return path;
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}
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return path;
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};
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var normalizePaths = function normalizePaths(paths) {
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if (!Array.isArray(paths)) {
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return [normalizePath(paths)];
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}
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return paths.map(function (p) {
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return normalizePath(p);
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});
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};
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var findFourCC = function findFourCC(bytes, paths) {
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paths = normalizePaths(paths);
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bytes = (0, _byteHelpers.toUint8)(bytes);
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var results = [];
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if (!paths.length) {
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// short-circuit the search for empty paths
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return results;
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}
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var i = 0;
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while (i < bytes.length) {
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var type = bytes.subarray(i, i + 4);
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var size = (bytes[i + 7] << 24 | bytes[i + 6] << 16 | bytes[i + 5] << 8 | bytes[i + 4]) >>> 0; // skip LIST/RIFF and get the actual type
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if ((0, _byteHelpers.bytesMatch)(type, CONSTANTS.LIST) || (0, _byteHelpers.bytesMatch)(type, CONSTANTS.RIFF) || (0, _byteHelpers.bytesMatch)(type, CONSTANTS.WAVE)) {
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type = bytes.subarray(i + 8, i + 12);
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i += 4;
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size -= 4;
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}
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var data = bytes.subarray(i + 8, i + 8 + size);
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if ((0, _byteHelpers.bytesMatch)(type, paths[0])) {
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if (paths.length === 1) {
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// this is the end of the path and we've found the box we were
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// looking for
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results.push(data);
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} else {
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// recursively search for the next box along the path
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var subresults = findFourCC(data, paths.slice(1));
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if (subresults.length) {
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results = results.concat(subresults);
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}
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}
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}
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i += 8 + data.length;
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} // we've finished searching all of bytes
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return results;
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};
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exports.findFourCC = findFourCC;
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