forked from um/web
67 lines
2.1 KiB
JavaScript
67 lines
2.1 KiB
JavaScript
import {AudioMimeType, GetArrayBuffer, GetFileInfo, GetMetaCoverURL, IsBytesEqual} from "./util";
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import {Decrypt as RawDecrypt} from "./raw";
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const musicMetadata = require("music-metadata-browser");
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const MagicHeader = [0x69, 0x66, 0x6D, 0x74]
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const MagicHeader2 = [0xfe, 0xfe, 0xfe, 0xfe]
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const FileTypeMap = {
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" WAV": ".wav",
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"FLAC": ".flac",
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" MP3": ".mp3",
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" A4M": ".m4a",
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}
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export async function Decrypt(file, raw_filename, raw_ext) {
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const oriData = new Uint8Array(await GetArrayBuffer(file));
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if (!IsBytesEqual(MagicHeader, oriData.slice(0, 4)) ||
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!IsBytesEqual(MagicHeader2, oriData.slice(8, 12))) {
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if (raw_ext === "xm") {
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return {status: false, message: "此xm文件已损坏"}
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} else {
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return await RawDecrypt(file, raw_filename, raw_ext, true)
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}
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}
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let typeText = (new TextDecoder()).decode(oriData.slice(4, 8))
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if (!FileTypeMap.hasOwnProperty(typeText)) {
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return {status: false, message: "未知的xm文件类型"}
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}
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let key = oriData[0xf]
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let dataOffset = oriData[0xc] | oriData[0xd] << 8 | oriData[0xe] << 16
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let audioData = oriData.slice(0x10);
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let lenAudioData = audioData.length;
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for (let cur = dataOffset; cur < lenAudioData; ++cur)
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audioData[cur] = (audioData[cur] - key) ^ 0xff;
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const ext = FileTypeMap[typeText];
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const mime = AudioMimeType[ext];
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let musicBlob = new Blob([audioData], {type: mime});
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const musicMeta = await musicMetadata.parseBlob(musicBlob);
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if (ext === "wav") {
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//todo:未知的编码方式
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musicMeta.common.album = "";
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musicMeta.common.artist = "";
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musicMeta.common.title = "";
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}
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const info = GetFileInfo(musicMeta.common.artist, musicMeta.common.title, raw_filename, "_");
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const imgUrl = GetMetaCoverURL(musicMeta);
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return {
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status: true,
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title: info.title,
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artist: info.artist,
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ext: ext,
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album: musicMeta.common.album,
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picture: imgUrl,
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file: URL.createObjectURL(musicBlob),
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mime: mime,
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rawExt: "xm"
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}
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}
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