1
0
forked from um/web
qqmusicunlock/src/decrypt/qmccache.ts
MengYX 76dd78130a all: format with prettier
(cherry picked from commit cad5b4d7deba4fbe4a40a17306ce49d3b2f13139)
2022-01-09 10:44:16 +08:00

51 lines
1.6 KiB
TypeScript

import {
AudioMimeType,
GetArrayBuffer,
GetCoverFromFile,
GetMetaFromFile,
SniffAudioExt,
SplitFilename,
} from '@/decrypt/utils';
import { Decrypt as QmcDecrypt, HandlerMap } from '@/decrypt/qmc';
import { DecryptResult } from '@/decrypt/entity';
import { parseBlob as metaParseBlob } from 'music-metadata-browser';
export async function Decrypt(file: Blob, raw_filename: string, _: string): Promise<DecryptResult> {
const buffer = new Uint8Array(await GetArrayBuffer(file));
let length = buffer.length;
for (let i = 0; i < length; i++) {
buffer[i] ^= 0xf4;
if (buffer[i] <= 0x3f) buffer[i] = buffer[i] * 4;
else if (buffer[i] <= 0x7f) buffer[i] = (buffer[i] - 0x40) * 4 + 1;
else if (buffer[i] <= 0xbf) buffer[i] = (buffer[i] - 0x80) * 4 + 2;
else buffer[i] = (buffer[i] - 0xc0) * 4 + 3;
}
let ext = SniffAudioExt(buffer, '');
const newName = SplitFilename(raw_filename);
let audioBlob: Blob;
if (ext !== '' || newName.ext === 'mp3') {
audioBlob = new Blob([buffer], { type: AudioMimeType[ext] });
} else if (newName.ext in HandlerMap) {
audioBlob = new Blob([buffer], { type: 'application/octet-stream' });
return QmcDecrypt(audioBlob, newName.name, newName.ext);
} else {
throw '不支持的QQ音乐缓存格式';
}
const tag = await metaParseBlob(audioBlob);
const { title, artist } = GetMetaFromFile(raw_filename, tag.common.title, tag.common.artist);
return {
title,
artist,
ext,
album: tag.common.album,
picture: GetCoverFromFile(tag),
file: URL.createObjectURL(audioBlob),
blob: audioBlob,
mime: AudioMimeType[ext],
};
}