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37 lines
955 B
37 lines
955 B
4 years ago
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import { toUint8, bytesMatch } from './byte-helpers.js';
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var ID3 = toUint8([0x49, 0x44, 0x33]);
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export var getId3Size = function getId3Size(bytes, offset) {
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if (offset === void 0) {
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offset = 0;
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}
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bytes = toUint8(bytes);
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var flags = bytes[offset + 5];
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var returnSize = bytes[offset + 6] << 21 | bytes[offset + 7] << 14 | bytes[offset + 8] << 7 | bytes[offset + 9];
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var footerPresent = (flags & 16) >> 4;
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if (footerPresent) {
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return returnSize + 20;
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}
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return returnSize + 10;
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};
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export var getId3Offset = function getId3Offset(bytes, offset) {
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if (offset === void 0) {
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offset = 0;
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}
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bytes = toUint8(bytes);
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if (bytes.length - offset < 10 || !bytesMatch(bytes, ID3, {
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offset: offset
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})) {
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return offset;
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}
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offset += getId3Size(bytes, offset); // recursive check for id3 tags as some files
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// have multiple ID3 tag sections even though
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// they should not.
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return getId3Offset(bytes, offset);
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};
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