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 { 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[] = []; 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 { 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((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 { 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 { const getStat = util.promisify(fs.stat); return (await getStat(path)).size; } /** * Calculate MD5 hash */ @bindThis private async calcHash(path: string): Promise { 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 { 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); }); }); } }