Add Partial Support For .mflac
parent
95de3e8cc5
commit
591c1a5312
@ -0,0 +1,118 @@
|
||||
const musicMetadata = require("music-metadata-browser");
|
||||
export {Decrypt}
|
||||
|
||||
async function Decrypt(file) {
|
||||
// 获取扩展名
|
||||
let filename_ext = file.name.substring(file.name.lastIndexOf(".") + 1, file.name.length).toLowerCase();
|
||||
if (filename_ext !== "mflac") return;
|
||||
// 读取文件
|
||||
const fileBuffer = await new Promise(resolve => {
|
||||
const reader = new FileReader();
|
||||
reader.onload = (e) => {
|
||||
resolve(e.target.result);
|
||||
};
|
||||
reader.readAsArrayBuffer(file);
|
||||
});
|
||||
const audioData = new Uint8Array(fileBuffer.slice(0, -0x170));
|
||||
const audioDataLen = audioData.length;
|
||||
|
||||
// 转换数据
|
||||
const seed = new Mask();
|
||||
if (!seed.DetectMask(audioData)) return;
|
||||
for (let cur = 0; cur < audioDataLen; ++cur) {
|
||||
audioData[cur] ^= seed.NextMask();
|
||||
}
|
||||
// 导出
|
||||
const musicData = new Blob([audioData], {type: "audio/flac"});
|
||||
const musicUrl = URL.createObjectURL(musicData);
|
||||
console.log(musicUrl);
|
||||
|
||||
// 读取Meta
|
||||
let tag = await musicMetadata.parseBlob(musicData);
|
||||
|
||||
// 处理无标题歌手
|
||||
let filename_array = file.name.substring(0, file.name.lastIndexOf(".")).split("-");
|
||||
let title = tag.common.title;
|
||||
let artist = tag.common.artist;
|
||||
if (filename_array.length > 1) {
|
||||
if (artist === undefined) artist = filename_array[0].trim();
|
||||
if (title === undefined) title = filename_array[1].trim();
|
||||
} else if (filename_array.length === 1) {
|
||||
if (title === undefined) title = filename_array[0].trim();
|
||||
}
|
||||
const filename = artist + " - " + title + ".flac";
|
||||
// 处理无封面
|
||||
let pic_url = "";
|
||||
|
||||
if (tag.common.picture !== undefined && tag.common.picture.length >= 1) {
|
||||
const picture = tag.common.picture[0];
|
||||
const blobPic = new Blob([picture.data], {type: picture.format});
|
||||
pic_url = URL.createObjectURL(blobPic);
|
||||
}
|
||||
// 返回*/
|
||||
return {
|
||||
filename: filename,
|
||||
title: title,
|
||||
artist: artist,
|
||||
album: tag.common.album,
|
||||
picture: pic_url,
|
||||
file: musicUrl,
|
||||
mime: "audio/flac"
|
||||
}
|
||||
}
|
||||
|
||||
class Mask {
|
||||
FLAC_HEADER = [0x66, 0x4C, 0x61, 0x43, 0x00];
|
||||
|
||||
constructor() {
|
||||
this.index = -1;
|
||||
this.mask_index = -1;
|
||||
this.mask = Array(128).fill(0x00);
|
||||
}
|
||||
|
||||
DetectMask(data) {
|
||||
|
||||
let search_len = data.length - 256, mask;
|
||||
for (let block_idx = 0; block_idx < search_len; block_idx += 128) {
|
||||
let flag = true;
|
||||
mask = data.slice(block_idx, block_idx + 128);
|
||||
let next_mask = data.slice(block_idx + 128, block_idx + 256);
|
||||
for (let idx = 0; idx < 128; idx++) {
|
||||
if (mask[idx] !== next_mask[idx]) {
|
||||
flag = false;
|
||||
break;
|
||||
}
|
||||
}
|
||||
if (!flag) continue;
|
||||
|
||||
|
||||
for (let test_idx = 0; test_idx < this.FLAC_HEADER.length; test_idx++) {
|
||||
let p = data[test_idx] ^ mask[test_idx];
|
||||
if (p !== this.FLAC_HEADER[test_idx]) {
|
||||
flag = false;
|
||||
debugger;
|
||||
break;
|
||||
}
|
||||
}
|
||||
if (!flag) continue;
|
||||
this.mask = mask;
|
||||
console.log(mask);
|
||||
return true;
|
||||
}
|
||||
return false;
|
||||
}
|
||||
|
||||
NextMask() {
|
||||
this.index++;
|
||||
this.mask_index++;
|
||||
if (this.index === 0x8000 || (this.index > 0x8000 && (this.index + 1) % 0x8000 === 0)) {
|
||||
this.index++;
|
||||
this.mask_index++;
|
||||
}
|
||||
if (this.mask_index >= 128) {
|
||||
this.mask_index -= 128;
|
||||
}
|
||||
return this.mask[this.mask_index]
|
||||
}
|
||||
|
||||
}
|
Loading…
Reference in New Issue