misskey-awawa/packages/backend/src/core/FileInfoService.ts

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import * as fs from 'node:fs';
import * as crypto from 'node:crypto';
import { join } from 'node:path';
import * as stream from 'node:stream';
import * as util from 'node:util';
import { Injectable } from '@nestjs/common';
import { FSWatcher } from 'chokidar';
import { fileTypeFromFile } from 'file-type';
import FFmpeg from 'fluent-ffmpeg';
import isSvg from 'is-svg';
import probeImageSize from 'probe-image-size';
import { type predictionType } from 'nsfwjs';
import sharp from 'sharp';
import { encode } from 'blurhash';
import { createTempDir } from '@/misc/create-temp.js';
import { AiService } from '@/core/AiService.js';
import { bindThis } from '@/decorators.js';
const pipeline = util.promisify(stream.pipeline);
export type FileInfo = {
size: number;
md5: string;
type: {
mime: string;
ext: string | null;
};
width?: number;
height?: number;
orientation?: number;
blurhash?: string;
sensitive: boolean;
porn: boolean;
warnings: string[];
};
const TYPE_OCTET_STREAM = {
mime: 'application/octet-stream',
ext: null,
};
const TYPE_SVG = {
mime: 'image/svg+xml',
ext: 'svg',
};
@Injectable()
export class FileInfoService {
constructor(
private aiService: AiService,
) {
}
/**
* Get file information
*/
@bindThis
public async getFileInfo(path: string, opts: {
skipSensitiveDetection: boolean;
sensitiveThreshold?: number;
sensitiveThresholdForPorn?: number;
enableSensitiveMediaDetectionForVideos?: boolean;
}): Promise<FileInfo> {
const warnings = [] as string[];
const size = await this.getFileSize(path);
const md5 = await this.calcHash(path);
let type = await this.detectType(path);
// image dimensions
let width: number | undefined;
let height: number | undefined;
let orientation: number | undefined;
if ([
'image/png',
'image/gif',
'image/jpeg',
'image/webp',
'image/avif',
'image/apng',
'image/bmp',
'image/tiff',
'image/svg+xml',
'image/vnd.adobe.photoshop',
].includes(type.mime)) {
const imageSize = await this.detectImageSize(path).catch(e => {
warnings.push(`detectImageSize failed: ${e}`);
return undefined;
});
// うまく判定できない画像は octet-stream にする
if (!imageSize) {
warnings.push('cannot detect image dimensions');
type = TYPE_OCTET_STREAM;
} else if (imageSize.wUnits === 'px') {
width = imageSize.width;
height = imageSize.height;
orientation = imageSize.orientation;
// 制限を超えている画像は octet-stream にする
if (imageSize.width > 16383 || imageSize.height > 16383) {
warnings.push('image dimensions exceeds limits');
type = TYPE_OCTET_STREAM;
}
} else {
warnings.push(`unsupported unit type: ${imageSize.wUnits}`);
}
}
let blurhash: string | undefined;
if ([
'image/jpeg',
'image/gif',
'image/png',
'image/apng',
'image/webp',
'image/avif',
'image/svg+xml',
].includes(type.mime)) {
blurhash = await this.getBlurhash(path).catch(e => {
warnings.push(`getBlurhash failed: ${e}`);
return undefined;
});
}
let sensitive = false;
let porn = false;
if (!opts.skipSensitiveDetection) {
await this.detectSensitivity(
path,
type.mime,
opts.sensitiveThreshold ?? 0.5,
opts.sensitiveThresholdForPorn ?? 0.75,
opts.enableSensitiveMediaDetectionForVideos ?? false,
).then(value => {
[sensitive, porn] = value;
}, error => {
warnings.push(`detectSensitivity failed: ${error}`);
});
}
return {
size,
md5,
type,
width,
height,
orientation,
blurhash,
sensitive,
porn,
warnings,
};
}
@bindThis
private async detectSensitivity(source: string, mime: string, sensitiveThreshold: number, sensitiveThresholdForPorn: number, analyzeVideo: boolean): Promise<[sensitive: boolean, porn: boolean]> {
let sensitive = false;
let porn = false;
function judgePrediction(result: readonly predictionType[]): [sensitive: boolean, porn: boolean] {
let sensitive = false;
let porn = false;
if ((result.find(x => x.className === 'Sexy')?.probability ?? 0) > sensitiveThreshold) sensitive = true;
if ((result.find(x => x.className === 'Hentai')?.probability ?? 0) > sensitiveThreshold) sensitive = true;
if ((result.find(x => x.className === 'Porn')?.probability ?? 0) > sensitiveThreshold) sensitive = true;
if ((result.find(x => x.className === 'Porn')?.probability ?? 0) > sensitiveThresholdForPorn) porn = true;
return [sensitive, porn];
}
if ([
'image/jpeg',
'image/png',
'image/webp',
].includes(mime)) {
const result = await this.aiService.detectSensitive(source);
if (result) {
[sensitive, porn] = judgePrediction(result);
}
} else if (analyzeVideo && (mime === 'image/apng' || mime.startsWith('video/'))) {
const [outDir, disposeOutDir] = await createTempDir();
try {
const command = FFmpeg()
.input(source)
.inputOptions([
'-skip_frame', 'nokey', // 可能ならキーフレームのみを取得してほしいとする(そうなるとは限らない)
'-lowres', '3', // 元の画質でデコードする必要はないので 1/8 画質でデコードしてもよいとする(そうなるとは限らない)
])
.noAudio()
.videoFilters([
{
filter: 'select', // フレームのフィルタリング
options: {
e: 'eq(pict_type,PICT_TYPE_I)', // I-Frame のみをフィルタするVP9 とかはデコードしてみないとわからないっぽい)
},
},
{
filter: 'blackframe', // 暗いフレームの検出
options: {
amount: '0', // 暗さに関わらず全てのフレームで測定値を取る
},
},
{
filter: 'metadata',
options: {
mode: 'select', // フレーム選択モード
key: 'lavfi.blackframe.pblack', // フレームにおける暗部の百分率(前のフィルタからのメタデータを参照する)
value: '50',
function: 'less', // 50% 未満のフレームを選択する50% 以上暗部があるフレームだと誤検知を招くかもしれないので)
},
},
{
filter: 'scale',
options: {
w: 299,
h: 299,
},
},
])
.format('image2')
.output(join(outDir, '%d.png'))
.outputOptions(['-vsync', '0']); // 可変フレームレートにすることで穴埋めをさせない
const results: ReturnType<typeof judgePrediction>[] = [];
let frameIndex = 0;
let targetIndex = 0;
let nextIndex = 1;
for await (const path of this.asyncIterateFrames(outDir, command)) {
try {
const index = frameIndex++;
if (index !== targetIndex) {
continue;
}
targetIndex = nextIndex;
nextIndex += index; // fibonacci sequence によってフレーム数制限を掛ける
const result = await this.aiService.detectSensitive(path);
if (result) {
results.push(judgePrediction(result));
}
} finally {
fs.promises.unlink(path);
}
}
sensitive = results.filter(x => x[0]).length >= Math.ceil(results.length * sensitiveThreshold);
porn = results.filter(x => x[1]).length >= Math.ceil(results.length * sensitiveThresholdForPorn);
} finally {
disposeOutDir();
}
}
return [sensitive, porn];
}
private async *asyncIterateFrames(cwd: string, command: FFmpeg.FfmpegCommand): AsyncGenerator<string, void> {
const watcher = new FSWatcher({
cwd,
disableGlobbing: true,
});
let finished = false;
command.once('end', () => {
finished = true;
watcher.close();
});
command.run();
for (let i = 1; true; i++) { // eslint-disable-line @typescript-eslint/no-unnecessary-condition
const current = `${i}.png`;
const next = `${i + 1}.png`;
const framePath = join(cwd, current);
if (await this.exists(join(cwd, next))) {
yield framePath;
} else if (!finished) { // eslint-disable-line @typescript-eslint/no-unnecessary-condition
watcher.add(next);
await new Promise<void>((resolve, reject) => {
watcher.on('add', function onAdd(path) {
if (path === next) { // 次フレームの書き出しが始まっているなら、現在フレームの書き出しは終わっている
watcher.unwatch(current);
watcher.off('add', onAdd);
resolve();
}
});
command.once('end', resolve); // 全てのフレームを処理し終わったなら、最終フレームである現在フレームの書き出しは終わっている
command.once('error', reject);
});
yield framePath;
} else if (await this.exists(framePath)) {
yield framePath;
} else {
return;
}
}
}
@bindThis
private exists(path: string): Promise<boolean> {
return fs.promises.access(path).then(() => true, () => false);
}
/**
* Detect MIME Type and extension
*/
@bindThis
public async detectType(path: string): Promise<{
mime: string;
ext: string | null;
}> {
// Check 0 byte
const fileSize = await this.getFileSize(path);
if (fileSize === 0) {
return TYPE_OCTET_STREAM;
}
const type = await fileTypeFromFile(path);
if (type) {
// XMLはSVGかもしれない
if (type.mime === 'application/xml' && await this.checkSvg(path)) {
return TYPE_SVG;
}
return {
mime: type.mime,
ext: type.ext,
};
}
// 種類が不明でもSVGかもしれない
if (await this.checkSvg(path)) {
return TYPE_SVG;
}
// それでも種類が不明なら application/octet-stream にする
return TYPE_OCTET_STREAM;
}
/**
* Check the file is SVG or not
*/
@bindThis
public async checkSvg(path: string) {
try {
const size = await this.getFileSize(path);
if (size > 1 * 1024 * 1024) return false;
return isSvg(fs.readFileSync(path));
} catch {
return false;
}
}
/**
* Get file size
*/
@bindThis
public async getFileSize(path: string): Promise<number> {
const getStat = util.promisify(fs.stat);
return (await getStat(path)).size;
}
/**
* Calculate MD5 hash
*/
@bindThis
private async calcHash(path: string): Promise<string> {
const hash = crypto.createHash('md5').setEncoding('hex');
await pipeline(fs.createReadStream(path), hash);
return hash.read();
}
/**
* Detect dimensions of image
*/
@bindThis
private async detectImageSize(path: string): Promise<{
width: number;
height: number;
wUnits: string;
hUnits: string;
orientation?: number;
}> {
const readable = fs.createReadStream(path);
const imageSize = await probeImageSize(readable);
readable.destroy();
return imageSize;
}
/**
* Calculate average color of image
*/
@bindThis
private getBlurhash(path: string): Promise<string> {
return new Promise((resolve, reject) => {
sharp(path)
.raw()
.ensureAlpha()
.resize(64, 64, { fit: 'inside' })
.toBuffer((err, buffer, info) => {
if (err) return reject(err);
let hash;
try {
hash = encode(new Uint8ClampedArray(buffer), info.width, info.height, 5, 5);
} catch (e) {
return reject(e);
}
resolve(hash);
});
});
}
}