import { AudioMimeType, GetArrayBuffer, GetCoverFromFile, GetMetaFromFile, SniffAudioExt, SplitFilename } from "@/decrypt/utils.ts"; 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 { 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] } }