initial commit

.dockerignore

@@ -0,0 +1,6 @@
+node_modules
+dist
+.git
+test/fixtures/*.mp4
+test/fixtures/*.mkv
+test/fixtures/*.mp3

.github/workflows/docker.yml

@@ -0,0 +1,56 @@
+name: Build and Push Docker Image
+
+on:
+  push:
+    branches: [main, master]
+    tags: ['v*']
+  pull_request:
+    branches: [main, master]
+
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository }}
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Log in to Container Registry
+        if: github.event_name != 'pull_request'
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Extract metadata
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+          tags: |
+            type=ref,event=branch
+            type=ref,event=pr
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+            type=sha
+
+      - name: Build and push
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          push: ${{ github.event_name != 'pull_request' }}
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max

.gitignore

@@ -0,0 +1,9 @@
+node_modules/
+dist/
+*.tsbuildinfo
+
+# Test fixtures are generated by test/fixtures/generate-test-fixtures.sh
+# (run automatically in Dockerfile.test) — no need to carry binaries in git.
+test/fixtures/*.mp4
+test/fixtures/*.mkv
+test/fixtures/*.mp3

Dockerfile

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+# MetaMesh Plugin: still-extractor
+# Extracts a representative frame from a video file
+
+FROM node:20-slim AS builder
+
+ENV PNPM_HOME="/pnpm"
+ENV PATH="$PNPM_HOME:$PATH"
+RUN npm install -g corepack@latest && corepack enable
+
+WORKDIR /app
+
+# Copy package files first for layer caching
+COPY package.json pnpm-lock.yaml ./
+RUN corepack install
+RUN --mount=type=cache,id=pnpm,target=/pnpm/store pnpm install --frozen-lockfile
+
+# Copy source and build
+COPY tsconfig.json ./
+COPY src/ ./src/
+RUN pnpm run build
+
+# Production image with ffmpeg
+FROM node:20-slim
+
+# ffmpeg does the seeking, decoding and JPEG encoding
+RUN apt-get update && apt-get install -y --no-install-recommends ffmpeg && rm -rf /var/lib/apt/lists/*
+
+ENV PNPM_HOME="/pnpm"
+ENV PATH="$PNPM_HOME:$PATH"
+RUN npm install -g corepack@latest && corepack enable
+
+WORKDIR /app
+
+COPY package.json pnpm-lock.yaml ./
+RUN corepack install
+RUN --mount=type=cache,id=pnpm,target=/pnpm/store pnpm install --frozen-lockfile --prod
+
+COPY --from=builder /app/dist ./dist
+
+EXPOSE 8080
+
+HEALTHCHECK --interval=30s --timeout=5s --start-period=5s --retries=3 \
+  CMD node -e "require('http').get('http://localhost:8080/health', (r) => process.exit(r.statusCode === 200 ? 0 : 1))"
+
+CMD ["node", "dist/index.js"]

Dockerfile.test

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+# MetaMesh Plugin: still-extractor - Test Image
+# Builds the plugin and runs tests with ffmpeg available
+
+FROM node:20-slim
+
+# Install ffmpeg for fixture generation and integration tests
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    ffmpeg \
+    && rm -rf /var/lib/apt/lists/*
+
+WORKDIR /app
+
+# Copy package files and install ALL dependencies (including devDependencies)
+COPY package.json tsconfig.json vitest.config.ts ./
+RUN npm install
+
+# Copy source and test files
+COPY src/ ./src/
+COPY test/ ./test/
+
+# Build the plugin
+RUN npm run build
+
+# Generate test fixtures
+RUN chmod +x ./test/fixtures/generate-test-fixtures.sh && \
+    ./test/fixtures/generate-test-fixtures.sh
+
+# Temp dir the extractor writes frames into before upload
+RUN mkdir -p /cache/temp && chmod 777 /cache
+
+ENV NODE_ENV=test
+ENV CACHE_PATH=/cache
+
+CMD ["npm", "test"]

README.md

@@ -1 +1,82 @@
-# metamesh-plugin-still-extractor
+# metamesh-plugin-still-extractor
+
+MetaMesh container plugin. Grabs a representative frame out of a local video
+file and stores it as a content-addressed JPEG, referenced from the video
+record as **`still`**.
+
+```
+video file ──ffmpeg seek+decode──► frame ──WebDAV PUT──► /files/plugin/still-extractor/
+                                                              │
+                                                   midhash256 │
+                                                              ▼
+                                              meta-core:  still = <cid>
+```
+
+## Why
+
+Artwork on a local file otherwise comes from TMDB, and only when a title match
+succeeds. `still` (METADATA_KEYS.md §6.1) is the episode-level thumbnail slot —
+reserved for a future TMDB season-detail fetch, and until now written by
+nobody. This plugin gives it a first writer from the one source that never
+404s and never depends on a match: the file itself.
+
+**A still is not a poster.** Nothing gates on it, its absence is not an error,
+and this plugin never writes `poster` — a frame grab masquerading as real
+artwork would propagate to every peer that replicates the record. If a TMDB
+episode still ever lands on the record first, this plugin steps aside.
+
+## What it writes
+
+| Key | Value |
+|---|---|
+| `still` | midhash256 CID of the extracted JPEG |
+
+Nothing else — in particular **no `stillPath`**. `/files/plugin` is a meta-core
+watcher root, so the JPEG gets its own record and CID alias and
+`LookupPathByCID` resolves it through the reverse index. See the header comment
+in `src/plugin.ts`.
+
+## How a frame is chosen
+
+1. Candidate offsets at 20 / 45 / 70 % of `fileinfo/duration`, clamped 2s away
+   from both ends (the head is logos and black, the tail is credits).
+2. At each offset, one ffmpeg run with **input seeking** (`-ss` before `-i`, so
+   it Range-seeks over WebDAV instead of decoding from zero) and
+   `thumbnail=60`, which picks the most representative of the next 60 frames.
+3. The encoded JPEG is measured (mean + stddev of a 32×32 grayscale reduction).
+   Black, blown-out and flat frames are rejected and the next offset is tried.
+4. All candidates rejected → `skipped`, no field written.
+
+The primary video stream is the largest one that **looks like moving video** —
+not `0:v:0`, and not simply the largest. ffprobe reports attached cover art as
+`codec_type=video`, and a 600×900 cover out-measures a 640×480 film.
+
+## Configuration
+
+Runtime config via meta-sort's plugin API (never `plugins.yml`):
+
+```bash
+curl -k -X PUT https://metasort-dev.localhost:8180/api/plugins/still-extractor/config \
+  -H "Content-Type: application/json" \
+  -d '{"seekPercents":"15,40,65","maxWidth":720,"jpegQuality":3}'
+```
+
+| Key | Default | What |
+|---|---|---|
+| `forceRecompute` | `false` | Re-extract even when `still` is already set |
+| `seekPercents` | `"20,45,70"` | Candidate offsets, as percentages of duration |
+| `maxWidth` | `640` | Frame is scaled down to at most this width |
+| `jpegQuality` | `4` | ffmpeg `-q:v`; lower is better quality |
+| `frameTimeoutMs` | `120000` | Hard kill for one ffmpeg grab |
+
+## Development
+
+```bash
+pnpm install && pnpm build
+docker build -t metamesh-plugin-still-extractor:main .
+./test.sh            # unit + fixture tests in a container with ffmpeg
+./test.sh --shell    # interactive debugging
+```
+
+Depends on `file-info` (for `fileType`) and `ffmpeg` (for `fileinfo/duration`
+and the `stream/{n}` table). Runs on the **background** queue.

package.json

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+{
+  "name": "@metazla/plugin-still-extractor",
+  "version": "1.0.0",
+  "packageManager": "[email protected]",
+  "description": "MetaMesh plugin: Extracts a representative frame from a video file and stores it as the record's `still`",
+  "type": "module",
+  "main": "dist/index.js",
+  "scripts": {
+    "build": "tsc",
+    "start": "node dist/index.js",
+    "test": "vitest run",
+    "test:watch": "vitest"
+  },
+  "dependencies": {
+    "fastify": "^5.0.0"
+  },
+  "devDependencies": {
+    "@types/node": "^20.0.0",
+    "typescript": "^5.3.0",
+    "vitest": "^1.0.0"
+  },
+  "engines": {
+    "node": ">=20.0.0"
+  }
+}

src/index.ts

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+/**
+ * MetaMesh Plugin: still-extractor
+ *
+ * ============================================================================
+ * PLUGIN FILE ACCESS ARCHITECTURE - WebDAV
+ * ============================================================================
+ *
+ * File access via WebDAV, resolved per request from the calling meta-core's
+ *   /urls -> webdavUrlInternal (WEBDAV_URL overrides):
+ *   - Read media files:  GET  /webdav/watch/...  or /webdav/test/...
+ *   - Write output:      PUT  /webdav/plugin/still-extractor/...
+ *   - Temp:              Local /cache/temp mount (frame written before WebDAV upload)
+ *
+ * SECURITY: Plugins use WebDAV for all file access. No /files mount needed.
+ *
+ * ============================================================================
+ */
+
+import Fastify from 'fastify';
+import type { HealthResponse, ProcessRequest, ProcessResponse, CallbackPayload, ConfigureRequest, ConfigureResponse } from './types.js';
+import { manifest, process as processFile, configure } from './plugin.js';
+
+const app = Fastify({ logger: true });
+let ready = false;
+
+app.get('/health', async (): Promise<HealthResponse> => ({
+    status: 'healthy',
+    ready,
+    version: manifest.version
+}));
+
+app.get('/manifest', async () => manifest);
+
+app.post<{ Body: ConfigureRequest }>('/configure', async (request): Promise<ConfigureResponse> => {
+    try {
+        configure(request.body.config || {});
+        console.log(`[${manifest.id}] Configuration updated`);
+        return { status: 'ok' };
+    } catch (error) {
+        console.error(`[${manifest.id}] Configuration error:`, error);
+        return { status: 'error', error: error instanceof Error ? error.message : String(error) };
+    }
+});
+
+app.post<{ Body: ProcessRequest }>('/process', async (request, reply) => {
+    const { taskId, cid, filePath, callbackUrl, metaCoreUrl } = request.body;
+
+    if (!taskId || !cid || !filePath || !callbackUrl || !metaCoreUrl) {
+        return reply.send({ status: 'rejected', error: 'Missing required fields' } as ProcessResponse);
+    }
+
+    // Process asynchronously and send callback when done
+    processFile(request.body, async (payload: CallbackPayload) => {
+        try {
+            await fetch(callbackUrl, {
+                method: 'POST',
+                headers: { 'Content-Type': 'application/json' },
+                body: JSON.stringify(payload)
+            });
+        } catch (error) {
+            console.error(`[${manifest.id}] Callback error:`, error);
+        }
+    }).catch((error) => {
+        console.error(`[${manifest.id}] Process error:`, error);
+    });
+
+    return reply.send({ status: 'accepted' } as ProcessResponse);
+});
+
+const port = parseInt(process.env.PORT || '8080', 10);
+
+app.listen({ port, host: '0.0.0.0' }).then(() => {
+    ready = true;
+    console.log(`[${manifest.id}] Listening on port ${port}`);
+});
+
+process.on('SIGTERM', async () => {
+    ready = false;
+    await app.close();
+    process.exit(0);
+});

src/meta-core-client.ts

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+/**
+ * meta-core API Client for writing metadata
+ * Fails gracefully if meta-core is unavailable (logs warning, returns without throwing)
+ */
+
+export class MetaCoreClient {
+    constructor(private baseUrl: string) {}
+
+    private async safeFetch(url: string, options: RequestInit): Promise<Response | null> {
+        try {
+            return await fetch(url, { ...options, signal: AbortSignal.timeout(5000) });
+        } catch (error) {
+            console.warn(`[MetaCoreClient] Warning: meta-core unavailable at ${this.baseUrl}`);
+            return null;
+        }
+    }
+
+    async setProperty(hashId: string, key: string, value: string): Promise<void> {
+        const response = await this.safeFetch(`${this.baseUrl}/meta/${hashId}/${key}`, {
+            method: 'PUT',
+            headers: { 'Content-Type': 'application/json' },
+            body: JSON.stringify({ value }),
+        });
+        if (response && !response.ok) {
+            console.warn(`[MetaCoreClient] Failed to set property: ${response.status}`);
+        }
+    }
+
+    async getProperty(hashId: string, key: string): Promise<string | null> {
+        const response = await this.safeFetch(`${this.baseUrl}/meta/${hashId}/${key}`, { method: 'GET' });
+        if (!response || response.status === 404) return null;
+        if (!response.ok) return null;
+        const data = await response.json() as { value?: string };
+        return data.value ?? null;
+    }
+
+    async mergeMetadata(hashId: string, metadata: Record<string, string>): Promise<void> {
+        const response = await this.safeFetch(`${this.baseUrl}/meta/${hashId}`, {
+            method: 'PATCH',
+            headers: { 'Content-Type': 'application/json' },
+            body: JSON.stringify(metadata),
+        });
+        if (response && !response.ok) {
+            console.warn(`[MetaCoreClient] Failed to merge metadata: ${response.status}`);
+        }
+    }
+
+    async deleteProperty(hashId: string, key: string): Promise<void> {
+        const response = await this.safeFetch(`${this.baseUrl}/meta/${hashId}/${key}`, { method: 'DELETE' });
+        if (response && !response.ok && response.status !== 404) {
+            console.warn(`[MetaCoreClient] Failed to delete property: ${response.status}`);
+        }
+    }
+
+    async addToSet(hashId: string, key: string, value: string): Promise<void> {
+        const response = await this.safeFetch(`${this.baseUrl}/meta/${hashId}/_add/${key}`, {
+            method: 'POST',
+            headers: { 'Content-Type': 'application/json' },
+            body: JSON.stringify({ value }),
+        });
+        if (response && !response.ok) {
+            console.warn(`[MetaCoreClient] Failed to add to set: ${response.status}`);
+        }
+    }
+
+    async getMetadata(hashId: string): Promise<Record<string, string>> {
+        const response = await this.safeFetch(`${this.baseUrl}/meta/${hashId}`, { method: 'GET' });
+        if (!response || response.status === 404) return {};
+        if (!response.ok) return {};
+        const data = await response.json() as { metadata?: Record<string, string> };
+        return data.metadata ?? {};
+    }
+
+    /**
+     * Compute the CID (Content Identifier) for a file
+     * Uses the meta-core /file/cid API endpoint
+     */
+    async computeFileCID(filePath: string): Promise<string | null> {
+        try {
+            const response = await this.safeFetch(`${this.baseUrl}/file/cid`, {
+                method: 'POST',
+                headers: { 'Content-Type': 'application/json' },
+                body: JSON.stringify({ path: filePath }),
+            });
+            if (!response || !response.ok) return null;
+            const data = await response.json() as { cid?: string };
+            return data.cid ?? null;
+        } catch (error) {
+            console.debug(`[MetaCoreClient] Failed to compute CID for ${filePath}:`, error);
+            return null;
+        }
+    }
+}

src/plugin.ts

@@ -0,0 +1,559 @@
+/**
+ * Still Extractor Plugin
+ *
+ * Grabs a representative frame out of a local video file and stores it as a
+ * content-addressed JPEG, referenced from the video record as `still`.
+ *
+ * ============================================================================
+ * WHY THIS EXISTS
+ * ============================================================================
+ * Artwork on a local file otherwise comes from TMDB, and only when a title
+ * match succeeds. `still` (METADATA_KEYS.md section 6.1) is the episode-level
+ * thumbnail slot, reserved for a future TMDB season-detail fetch and until now
+ * written by nobody. This plugin gives it a first writer from the one source
+ * that never 404s and never depends on a match: the file itself.
+ *
+ * A still is NOT a poster. Nothing gates on it and its absence is not an error
+ * — hence `skipped` rather than `failed` on every "couldn't get a usable
+ * frame" path. We never write `poster`: a frame grab masquerading as a real
+ * poster would propagate to every peer that replicates the record.
+ *
+ * ============================================================================
+ * PLUGIN FILE ACCESS ARCHITECTURE - WebDAV
+ * ============================================================================
+ * File access via WebDAV, on the meta-core named by each /process request
+ * (its /urls -> webdavUrlInternal; WEBDAV_URL overrides):
+ *   - Read media files:  GET  /webdav/watch/...  or /webdav/test/...
+ *   - Write output:      PUT  /webdav/plugin/still-extractor/...
+ *   - Temp:              /cache/temp (frame written by ffmpeg before upload)
+ *
+ * We deliberately do NOT write a `stillPath` sibling. METADATA_KEYS.md names
+ * one, but that is the gateway/peer_proxy mirroring convention: on the
+ * meta-sort path `/files/plugin` is a watcher root
+ * (meta-core/internal/config/config.go DefaultWatcherPaths), so the JPEG gets
+ * its own record and midhash alias and `LookupPathByCID` resolves it through
+ * the reverse index — "There is no path-companion sidecar field"
+ * (meta-core/internal/storage/client.go). The tmdb plugin writes `poster`
+ * without `posterPath` for the same reason.
+ * ============================================================================
+ */
+
+import { spawn } from 'child_process';
+import { createHash, randomBytes } from 'crypto';
+import { mkdirSync, readFileSync, existsSync, unlinkSync } from 'fs';
+import * as path from 'path';
+import type { PluginManifest, ProcessRequest, CallbackPayload } from './types.js';
+import { MetaCoreClient } from './meta-core-client.js';
+import { getWebDAVClient, WebDAVClient } from './webdav-client.js';
+
+const PLUGIN_OUTPUT_WEBDAV_PATH = '/files/plugin/still-extractor';
+const TEMP_PATH = '/cache/temp';
+
+export const manifest: PluginManifest = {
+    id: 'still-extractor',
+    name: 'Still Extractor',
+    version: '1.0.0',
+    description: 'Extracts a representative frame from a video file and stores it as the record\'s `still`',
+    author: 'MetaMesh',
+    // file-info gives us `fileType`; ffmpeg gives us `fileinfo/duration` and
+    // the `stream/{n}` table we pick the primary video stream out of.
+    dependencies: ['file-info', 'ffmpeg'],
+    priority: 55,
+    color: '#9C27B0',
+    // One seek + one decode over HTTP. Never the fast queue.
+    defaultQueue: 'background',
+    timeout: 300000,
+    schema: {
+        still: {
+            label: 'Still',
+            type: 'cid',
+            readonly: true,
+            hint: 'CID of a frame extracted from the video itself (best-effort episode thumbnail)',
+        },
+    },
+    config: {
+        forceRecompute: { type: 'boolean', label: 'Force Recompute', default: false },
+        seekPercents: { type: 'string', label: 'Seek Percents', default: '20,45,70' },
+        maxWidth: { type: 'number', label: 'Max Width (px)', default: 640 },
+        jpegQuality: { type: 'number', label: 'JPEG Quality (ffmpeg -q:v, lower is better)', default: 4 },
+        frameTimeoutMs: { type: 'number', label: 'Per-Frame ffmpeg Timeout (ms)', default: 120000 },
+    },
+};
+
+// Configuration
+let forceRecompute = false;
+let seekPercents = [20, 45, 70];
+let maxWidth = 640;
+let jpegQuality = 4;
+let frameTimeoutMs = 120000;
+
+export function configure(config: Record<string, unknown>): void {
+    forceRecompute = config.forceRecompute === true;
+    if (typeof config.seekPercents === 'string') {
+        const parsed = config.seekPercents
+            .split(',')
+            .map((p) => Number(p.trim()))
+            .filter((p) => Number.isFinite(p) && p > 0 && p < 100);
+        if (parsed.length > 0) seekPercents = parsed;
+    }
+    if (Number.isFinite(Number(config.maxWidth))) maxWidth = Number(config.maxWidth);
+    if (Number.isFinite(Number(config.jpegQuality))) jpegQuality = Number(config.jpegQuality);
+    if (Number.isFinite(Number(config.frameTimeoutMs))) frameTimeoutMs = Number(config.frameTimeoutMs);
+    console.log(
+        `[still-extractor] Config: forceRecompute=${forceRecompute}, seekPercents=${seekPercents.join(',')}, ` +
+        `maxWidth=${maxWidth}, jpegQuality=${jpegQuality}, frameTimeoutMs=${frameTimeoutMs}`
+    );
+}
+
+/**
+ * Compute midhash256 CID from a Buffer (matches meta-hash algorithm).
+ * Copied verbatim from metamesh-plugin-subtitle-extractor.
+ */
+export function computeMidHash256FromBuffer(data: Buffer): string {
+    const SAMPLE_SIZE = 1024 * 1024; // 1MB
+    const MIDHASH_VARINT = Buffer.from([0x80, 0x20]);
+
+    const fileSize = data.length;
+
+    const sizeBuffer = Buffer.allocUnsafe(8);
+    sizeBuffer.writeBigUInt64BE(BigInt(fileSize), 0);
+
+    let sampleData: Buffer;
+    if (fileSize <= SAMPLE_SIZE) {
+        sampleData = data;
+    } else {
+        const middleOffset = Math.floor((fileSize - SAMPLE_SIZE) / 2);
+        sampleData = data.subarray(middleOffset, middleOffset + SAMPLE_SIZE);
+    }
+
+    const hashInput = Buffer.concat([sizeBuffer, sampleData]);
+    const hashBuffer = createHash('sha256').update(hashInput).digest();
+
+    const cidBytes = Buffer.concat([
+        Buffer.from([0x01]),
+        MIDHASH_VARINT,
+        MIDHASH_VARINT,
+        Buffer.from([0x20]),
+        hashBuffer
+    ]);
+
+    const base32Chars = 'abcdefghijklmnopqrstuvwxyz234567';
+    let cid = 'b';
+    let bits = 0;
+    let value = 0;
+    for (const byte of cidBytes) {
+        value = (value << 8) | byte;
+        bits += 8;
+        while (bits >= 5) {
+            bits -= 5;
+            cid += base32Chars[(value >> bits) & 0x1f];
+        }
+    }
+    if (bits > 0) {
+        cid += base32Chars[(value << (5 - bits)) & 0x1f];
+    }
+
+    return cid;
+}
+
+/** Sanitize filename by removing invalid characters. */
+export function sanitizeFilename(name: string): string {
+    return name
+        .replace(/[<>:"/\\|?*]/g, '')
+        .replace(/\s+/g, ' ')
+        .trim();
+}
+
+/**
+ * Output filename for a still.
+ *
+ * The source CID is part of the name — unlike the tmdb plugin, which
+ * deliberately leaves the file CID out so every release of one movie shares a
+ * poster. A still belongs to exactly one file, so two files with the same
+ * basename must not collide.
+ */
+export function stillFilename(filePath: string, sourceCid: string): string {
+    const base = sanitizeFilename(path.basename(filePath, path.extname(filePath)));
+    const shortCid = sourceCid.slice(-12);
+    return `${base}[${shortCid}]_still.jpg`;
+}
+
+export interface VideoStream {
+    /** Absolute ffmpeg stream index — what `-map 0:<index>` wants. */
+    index: number;
+    width?: number;
+    height?: number;
+    codec?: string;
+    frameRate?: string;
+}
+
+/**
+ * Codecs that are a single picture, not a moving image. An `attached_pic`
+ * stream is almost always one of these.
+ */
+const STILL_IMAGE_CODECS = new Set(['mjpeg', 'png', 'bmp', 'gif', 'webp', 'tiff']);
+
+/**
+ * Pick the primary video stream out of the ffmpeg plugin's `stream/{n}` table.
+ *
+ * ⚠ NOT `0:v:0`, and ⚠ not simply the largest. ffprobe reports attached cover
+ * art (`attached_pic`) as `codec_type=video`, and the ffmpeg plugin's
+ * `embeddedimage` branch never fires for it, so an embedded poster lands here
+ * as a perfectly ordinary `type:'video'` stream — which `0:v:0` would happily
+ * extract instead of the film. Nor can we just take the biggest: a 600x900
+ * cover out-measures a 640x480 video.
+ *
+ * The stream table does not carry dispositions, so we use what it does carry.
+ * The ffmpeg plugin drops `avg_frame_rate` when it is `0/0` (plugin.ts), and an
+ * attached picture has no frame rate — so "has a frameRate and is not a
+ * still-image codec" separates moving pictures from covers. Largest area wins
+ * within the better class; if nothing looks like moving video we fall back to
+ * the largest of whatever is there rather than giving up.
+ *
+ * Accepts both shapes meta-core hands back: the namespaced `stream/{n}` keys
+ * the ffmpeg plugin writes, and the flattened `stream` array.
+ */
+export function selectPrimaryVideoStream(existingMeta: Record<string, string> | undefined): VideoStream | null {
+    if (!existingMeta) return null;
+
+    const raw: unknown[] = [];
+
+    const flattened = existingMeta['stream'] as unknown;
+    if (flattened) {
+        try {
+            const arr = Array.isArray(flattened) ? flattened : JSON.parse(String(flattened));
+            if (Array.isArray(arr)) raw.push(...arr);
+        } catch {
+            // fall through to the namespaced form
+        }
+    }
+
+    if (raw.length === 0) {
+        for (const [key, value] of Object.entries(existingMeta)) {
+            if (key.startsWith('stream/')) raw.push(value);
+        }
+    }
+
+    const moving: VideoStream[] = [];
+    const other: VideoStream[] = [];
+
+    for (const entry of raw) {
+        let stream: {
+            type?: string; index?: number; width?: number; height?: number;
+            codec?: string; frameRate?: string;
+        };
+        try {
+            stream = typeof entry === 'string' ? JSON.parse(entry) : (entry as typeof stream);
+        } catch {
+            continue;
+        }
+        if (!stream || stream.type !== 'video' || stream.index == null) continue;
+
+        const candidate: VideoStream = {
+            index: Number(stream.index),
+            width: stream.width != null ? Number(stream.width) : undefined,
+            height: stream.height != null ? Number(stream.height) : undefined,
+            codec: stream.codec,
+            frameRate: stream.frameRate,
+        };
+
+        const looksMoving =
+            !!candidate.frameRate && !STILL_IMAGE_CODECS.has((candidate.codec ?? '').toLowerCase());
+        (looksMoving ? moving : other).push(candidate);
+    }
+
+    const area = (s: VideoStream) => (s.width ?? 0) * (s.height ?? 0);
+    const pool = moving.length > 0 ? moving : other;
+    return pool.reduce<VideoStream | null>((best, s) => (!best || area(s) > area(best) ? s : best), null);
+}
+
+/**
+ * Seek offsets to try, in order.
+ *
+ * Clamped away from both ends: the head is titles/logos/black and the tail is
+ * credits. A file with no usable duration gets a blind 10s attempt and then
+ * the very start, which is all we can honestly do.
+ */
+export function candidateOffsets(durationSec: number | undefined, percents: number[] = seekPercents): number[] {
+    if (!durationSec || !Number.isFinite(durationSec) || durationSec <= 0) {
+        return [10, 0];
+    }
+    if (durationSec <= 4) {
+        return [Math.max(0, durationSec / 2)];
+    }
+    const lo = 2;
+    const hi = durationSec - 2;
+    const offsets = percents
+        .map((p) => (durationSec * p) / 100)
+        .map((t) => Math.min(hi, Math.max(lo, t)));
+    return Array.from(new Set(offsets.map((t) => Math.round(t * 1000) / 1000)));
+}
+
+export interface FrameStats {
+    mean: number;
+    stddev: number;
+}
+
+/** Mean + standard deviation of an 8-bit grayscale buffer, both 0..255. */
+export function frameStats(gray: Buffer): FrameStats {
+    if (gray.length === 0) return { mean: 0, stddev: 0 };
+    let sum = 0;
+    for (const v of gray) sum += v;
+    const mean = sum / gray.length;
+    let variance = 0;
+    for (const v of gray) variance += (v - mean) ** 2;
+    return { mean, stddev: Math.sqrt(variance / gray.length) };
+}
+
+/**
+ * Is this frame worth keeping?
+ *
+ * Rejects the three things a blind seek lands on far more often than you would
+ * expect: a black frame, a white/blown card, and a flat single-colour fade.
+ * `thumbnail=N` already avoids most of them; this is the backstop.
+ */
+export function isUsableFrame(stats: FrameStats): boolean {
+    if (stats.stddev < 6) return false;          // flat: fade, solid colour, blank card
+    if (stats.mean < 12 || stats.mean > 243) return false; // black / blown out
+    return true;
+}
+
+/** Run a command, resolving with its exit code, stdout and stderr. Killed hard on timeout. */
+function run(
+    cmd: string,
+    args: string[],
+    timeoutMs: number
+): Promise<{ code: number | null; stdout: Buffer; stderr: string; timedOut: boolean }> {
+    return new Promise((resolve) => {
+        const child = spawn(cmd, args, { stdio: ['ignore', 'pipe', 'pipe'] });
+        const stdout: Buffer[] = [];
+        let stderr = '';
+        let timedOut = false;
+
+        const timer = setTimeout(() => {
+            timedOut = true;
+            child.kill('SIGKILL');
+        }, timeoutMs);
+
+        child.stdout.on('data', (d: Buffer) => stdout.push(d));
+        child.stderr.on('data', (d: Buffer) => {
+            // Keep the tail only — a broken input can spew megabytes.
+            stderr = (stderr + d.toString()).slice(-4000);
+        });
+        child.on('error', (err) => {
+            clearTimeout(timer);
+            resolve({ code: null, stdout: Buffer.concat(stdout), stderr: stderr + String(err), timedOut });
+        });
+        child.on('close', (code) => {
+            clearTimeout(timer);
+            resolve({ code, stdout: Buffer.concat(stdout), stderr, timedOut });
+        });
+    });
+}
+
+/**
+ * Grab one frame at `offsetSec` and return the encoded JPEG.
+ *
+ * ⚠ `-ss` goes BEFORE `-i`. Input seeking makes ffmpeg jump via HTTP Range;
+ * output seeking (`-ss` after `-i`) decodes every frame from zero, which over
+ * WebDAV means pulling the whole file to reach the 20% mark. On MKV expect a
+ * tail read regardless — the cue index lives at EOF.
+ */
+export async function grabFrame(
+    input: string,
+    streamIndex: number,
+    offsetSec: number,
+    outputPath: string
+): Promise<Buffer | null> {
+    const args = ['-y', '-hide_banner', '-loglevel', 'error'];
+
+    // rw_timeout is a protocol option; only http/tcp accept it, and passing it
+    // to the file protocol makes ffmpeg bail before it starts.
+    if (/^https?:\/\//i.test(input)) {
+        args.push('-rw_timeout', '30000000'); // microseconds
+    }
+
+    args.push(
+        '-ss', String(offsetSec),
+        '-i', input,
+        '-map', `0:${streamIndex}`,
+        '-an', '-sn', '-dn',
+        '-frames:v', '1',
+        // thumbnail=N picks the most representative of the next N frames rather
+        // than whatever the seek happened to land on.
+        '-vf', `thumbnail=60,scale='min(iw,${maxWidth})':-2`,
+        '-q:v', String(jpegQuality),
+        '-f', 'image2',
+        outputPath
+    );
+
+    const result = await run('ffmpeg', args, frameTimeoutMs);
+    if (result.timedOut) {
+        console.warn(`[still-extractor] ffmpeg timed out at ${offsetSec}s`);
+        return null;
+    }
+    if (result.code !== 0 || !existsSync(outputPath)) {
+        console.warn(`[still-extractor] ffmpeg failed at ${offsetSec}s: ${result.stderr.trim() || `exit ${result.code}`}`);
+        return null;
+    }
+
+    const jpeg = readFileSync(outputPath);
+    return jpeg.length > 0 ? jpeg : null;
+}
+
+/**
+ * Measure a JPEG we already have on disk.
+ *
+ * Deliberately a second ffmpeg pass on the local temp file rather than a second
+ * output on the grab command: two filter chains off one input would each run
+ * their own `thumbnail` instance, and there is no guarantee the frame we
+ * measured is the frame we encoded. This decodes a ~40 KB local file — no
+ * seek, no network.
+ */
+export async function statsForJpeg(jpegPath: string): Promise<FrameStats | null> {
+    const result = await run(
+        'ffmpeg',
+        ['-hide_banner', '-loglevel', 'error', '-i', jpegPath,
+         '-vf', 'scale=32:32,format=gray', '-f', 'rawvideo', '-'],
+        15000
+    );
+    if (result.code !== 0 || result.stdout.length === 0) return null;
+    return frameStats(result.stdout);
+}
+
+export interface ExtractResult {
+    jpeg: Buffer;
+    offsetSec: number;
+    stats: FrameStats;
+}
+
+/**
+ * Walk the candidate offsets until one yields a usable frame.
+ *
+ * Returns null when every candidate was black, flat, or unreadable — that is a
+ * `skipped`, not a failure.
+ */
+export async function extractStill(
+    input: string,
+    streamIndex: number,
+    durationSec: number | undefined,
+    tempPath: string = TEMP_PATH
+): Promise<ExtractResult | null> {
+    mkdirSync(tempPath, { recursive: true });
+    // NB: `process` is this module's own export, not node's global — hence a
+    // random suffix rather than a pid for uniqueness between concurrent tasks.
+    const outputPath = path.join(tempPath, `still-${randomBytes(6).toString('hex')}.jpg`);
+
+    try {
+        for (const offsetSec of candidateOffsets(durationSec)) {
+            const jpeg = await grabFrame(input, streamIndex, offsetSec, outputPath);
+            if (!jpeg) continue;
+
+            const stats = await statsForJpeg(outputPath);
+            if (!stats) {
+                console.warn(`[still-extractor] Could not measure frame at ${offsetSec}s`);
+                continue;
+            }
+            if (!isUsableFrame(stats)) {
+                console.log(
+                    `[still-extractor] Rejected frame at ${offsetSec}s ` +
+                    `(mean=${stats.mean.toFixed(1)}, stddev=${stats.stddev.toFixed(1)})`
+                );
+                continue;
+            }
+
+            console.log(
+                `[still-extractor] Accepted frame at ${offsetSec}s ` +
+                `(mean=${stats.mean.toFixed(1)}, stddev=${stats.stddev.toFixed(1)}, ${jpeg.length} bytes)`
+            );
+            return { jpeg, offsetSec, stats };
+        }
+        return null;
+    } finally {
+        if (existsSync(outputPath)) {
+            try { unlinkSync(outputPath); } catch { /* best effort */ }
+        }
+    }
+}
+
+/** Upload the frame and return its CID. */
+async function storeStill(
+    client: WebDAVClient,
+    jpeg: Buffer,
+    filePath: string,
+    sourceCid: string
+): Promise<string> {
+    const webdavPath = `${PLUGIN_OUTPUT_WEBDAV_PATH}/${stillFilename(filePath, sourceCid)}`;
+    await client.writeFile(webdavPath, jpeg);
+    console.log(`[still-extractor] Uploaded still to WebDAV: ${webdavPath}`);
+    return computeMidHash256FromBuffer(jpeg);
+}
+
+export async function process(
+    request: ProcessRequest,
+    sendCallback: (payload: CallbackPayload) => Promise<void>
+): Promise<void> {
+    const startTime = Date.now();
+    const { taskId, cid, filePath, existingMeta } = request;
+    const metaCore = new MetaCoreClient(request.metaCoreUrl);
+
+    const skip = (reason: string) =>
+        sendCallback({ taskId, status: 'skipped', duration: Date.now() - startTime, reason });
+
+    try {
+        if (existingMeta?.fileType !== 'video') {
+            await skip('Not a video file');
+            return;
+        }
+
+        if (existingMeta?.still && !forceRecompute) {
+            // Also the mechanism that keeps this plugin from ever fighting a
+            // future TMDB episode-still writer: authoritative artwork wins by
+            // arriving first and never being overwritten from here.
+            await skip('Still already present');
+            return;
+        }
+
+        const stream = selectPrimaryVideoStream(existingMeta);
+        if (!stream) {
+            await skip('No video stream');
+            return;
+        }
+
+        // WebDAV of the very core we're enriching, so the frame bytes and the
+        // CID we write can never point at different cores.
+        const webdavClient = await getWebDAVClient(request.metaCoreUrl);
+        if (!webdavClient) {
+            await sendCallback({
+                taskId,
+                status: 'failed',
+                duration: Date.now() - startTime,
+                error: 'No WebDAV endpoint available',
+            });
+            return;
+        }
+
+        const duration = Number(existingMeta?.['fileinfo/duration']);
+        const input = webdavClient.toWebDAVUrl(filePath);
+
+        const extracted = await extractStill(input, stream.index, Number.isFinite(duration) ? duration : undefined);
+        if (!extracted) {
+            await skip('No usable frame');
+            return;
+        }
+
+        const stillCid = await storeStill(webdavClient, extracted.jpeg, filePath, cid);
+        await metaCore.setProperty(cid, 'still', stillCid);
+        console.log(`[still-extractor] Set still CID: ${stillCid}`);
+
+        await sendCallback({ taskId, status: 'completed', duration: Date.now() - startTime });
+    } catch (error) {
+        console.error(`[still-extractor] Error processing ${filePath}:`, error);
+        await sendCallback({
+            taskId,
+            status: 'failed',
+            duration: Date.now() - startTime,
+            error: error instanceof Error ? error.message : String(error),
+        });
+    }
+}

src/types.ts

@@ -0,0 +1,70 @@
+/**
+ * MetaMesh Plugin Types
+ */
+
+export interface PluginManifest {
+    id: string;
+    name: string;
+    version: string;
+    description?: string;
+    author?: string;
+    dependencies?: string[];
+    schema?: Record<string, SchemaField>;
+    config?: Record<string, ConfigField>;
+    priority?: number;
+    color?: string;
+    defaultQueue?: 'fast' | 'background';
+    timeout?: number;
+}
+
+export interface SchemaField {
+    label: string;
+    type?: 'string' | 'number' | 'boolean' | 'select' | 'text' | 'array' | 'json' | 'cid';
+    readonly?: boolean;
+    hint?: string;
+}
+
+export interface ConfigField {
+    type: 'string' | 'number' | 'boolean' | 'select';
+    label?: string;
+    required?: boolean;
+    default?: unknown;
+    secret?: boolean;
+}
+
+export interface HealthResponse {
+    status: 'healthy' | 'unhealthy';
+    ready: boolean;
+    version: string;
+}
+
+export interface ProcessRequest {
+    taskId: string;
+    cid: string;
+    filePath: string;
+    callbackUrl: string;
+    metaCoreUrl: string;
+    existingMeta?: Record<string, string>;
+}
+
+export interface ProcessResponse {
+    status: 'accepted' | 'rejected';
+    error?: string;
+}
+
+export interface CallbackPayload {
+    taskId: string;
+    status: 'completed' | 'failed' | 'skipped';
+    duration: number;
+    error?: string;
+    reason?: string;
+}
+
+export interface ConfigureRequest {
+    config: Record<string, unknown>;
+}
+
+export interface ConfigureResponse {
+    status: 'ok' | 'error';
+    error?: string;
+}

src/webdav-client.ts

@@ -0,0 +1,199 @@
+/**
+ * WebDAV Client for Plugin File Access
+ *
+ * Provides HTTP-based file access to meta-sort's WebDAV endpoint.
+ * Replaces direct filesystem access for containerized plugins.
+ */
+
+export interface FileStats {
+    size: number;
+    mtime?: Date;
+}
+
+export class WebDAVClient {
+    private baseUrl: string;
+
+    constructor(baseUrl: string) {
+        // Remove trailing slash if present
+        this.baseUrl = baseUrl.replace(/\/$/, '');
+    }
+
+    /**
+     * Convert absolute file path to WebDAV URL
+     * Strips /files prefix and appends to base URL
+     */
+    toWebDAVUrl(filePath: string): string {
+        // filePath is like "/files/watch/movie.mkv"
+        // We need to convert to "http://meta-sort-dev/webdav/watch/movie.mkv"
+        let relativePath = filePath;
+
+        // Strip /files prefix if present
+        if (relativePath.startsWith('/files/')) {
+            relativePath = relativePath.substring(6); // Remove "/files"
+        } else if (relativePath.startsWith('/files')) {
+            relativePath = relativePath.substring(6);
+        }
+
+        // Ensure path starts with /
+        if (!relativePath.startsWith('/')) {
+            relativePath = '/' + relativePath;
+        }
+
+        return this.baseUrl + relativePath;
+    }
+
+    /**
+     * Get file stats (size, mtime) via HTTP HEAD request
+     */
+    async stat(filePath: string): Promise<FileStats> {
+        const url = this.toWebDAVUrl(filePath);
+
+        const response = await fetch(url, { method: 'HEAD' });
+
+        if (!response.ok) {
+            throw new Error(`WebDAV HEAD failed for ${filePath}: ${response.status} ${response.statusText}`);
+        }
+
+        const contentLength = response.headers.get('content-length');
+        const lastModified = response.headers.get('last-modified');
+
+        return {
+            size: contentLength ? parseInt(contentLength, 10) : 0,
+            mtime: lastModified ? new Date(lastModified) : undefined,
+        };
+    }
+
+    /**
+     * Read first N bytes of a file (for magic byte detection)
+     * Uses HTTP Range request
+     */
+    async readBytes(filePath: string, start: number, end: number): Promise<Buffer> {
+        const url = this.toWebDAVUrl(filePath);
+
+        const response = await fetch(url, {
+            method: 'GET',
+            headers: {
+                'Range': `bytes=${start}-${end}`,
+            },
+        });
+
+        if (!response.ok && response.status !== 206) {
+            throw new Error(`WebDAV Range GET failed for ${filePath}: ${response.status} ${response.statusText}`);
+        }
+
+        const arrayBuffer = await response.arrayBuffer();
+        return Buffer.from(arrayBuffer);
+    }
+
+    /**
+     * Read entire file as buffer (for small files only)
+     */
+    async readFile(filePath: string): Promise<Buffer> {
+        const url = this.toWebDAVUrl(filePath);
+
+        const response = await fetch(url, { method: 'GET' });
+
+        if (!response.ok) {
+            throw new Error(`WebDAV GET failed for ${filePath}: ${response.status} ${response.statusText}`);
+        }
+
+        const arrayBuffer = await response.arrayBuffer();
+        return Buffer.from(arrayBuffer);
+    }
+
+    /**
+     * Write file via HTTP PUT
+     */
+    async writeFile(filePath: string, data: Buffer | string): Promise<void> {
+        const url = this.toWebDAVUrl(filePath);
+
+        const response = await fetch(url, {
+            method: 'PUT',
+            body: data,
+            headers: {
+                'Content-Type': 'application/octet-stream',
+            },
+        });
+
+        if (!response.ok) {
+            throw new Error(`WebDAV PUT failed for ${filePath}: ${response.status} ${response.statusText}`);
+        }
+    }
+
+    /**
+     * Check if file exists via HTTP HEAD
+     */
+    async exists(filePath: string): Promise<boolean> {
+        const url = this.toWebDAVUrl(filePath);
+
+        try {
+            const response = await fetch(url, { method: 'HEAD' });
+            return response.ok;
+        } catch {
+            return false;
+        }
+    }
+}
+
+/**
+ * WebDAV client for the meta-core that drove a /process call.
+ *
+ * The endpoint is read from that core's own /urls (`webdavUrlInternal`),
+ * so blobs always land in the /files of the core we write metadata to. A feeder
+ * whose plugins run beside it but enrich a remote hub core needs no per-stack
+ * wiring, and it is impossible to write posters into one core while pointing
+ * CIDs at another.
+ *
+ * WEBDAV_URL still wins when set — an explicit override for tests and for
+ * topologies where the core's advertised internal URL isn't reachable from here.
+ *
+ * Resolutions are cached per meta-core URL; failures are not, so a core that is
+ * still starting up is retried on the next task.
+ */
+const clientCache = new Map<string, Promise<WebDAVClient | null>>();
+
+async function resolveWebDAVUrl(metaCoreUrl: string): Promise<string | null> {
+    // /urls, not /api/urls — metaCoreUrl points at the meta-core backend, whose
+    // discovery routes are unprefixed (same base the /meta/* writes use).
+    const base = metaCoreUrl.replace(/\/$/, '');
+    const response = await fetch(`${base}/urls`, { signal: AbortSignal.timeout(5000) });
+
+    if (!response.ok) {
+        throw new Error(`GET ${base}/urls failed: ${response.status} ${response.statusText}`);
+    }
+
+    const urls = await response.json() as { webdavUrlInternal?: string; webdavUrl?: string };
+    return urls.webdavUrlInternal ?? urls.webdavUrl ?? null;
+}
+
+export async function getWebDAVClient(metaCoreUrl: string): Promise<WebDAVClient | null> {
+    const override = process.env.WEBDAV_URL;
+    if (override) {
+        return new WebDAVClient(override);
+    }
+
+    let pending = clientCache.get(metaCoreUrl);
+    if (!pending) {
+        pending = resolveWebDAVUrl(metaCoreUrl).then((webdavUrl) => {
+            if (!webdavUrl) {
+                console.warn(`[webdav-client] meta-core ${metaCoreUrl} advertises no WebDAV URL`);
+                return null;
+            }
+            console.log(`[webdav-client] Using WebDAV endpoint ${webdavUrl} (from ${metaCoreUrl})`);
+            return new WebDAVClient(webdavUrl);
+        });
+        clientCache.set(metaCoreUrl, pending);
+    }
+
+    try {
+        const client = await pending;
+        if (!client) {
+            clientCache.delete(metaCoreUrl);
+        }
+        return client;
+    } catch (error) {
+        clientCache.delete(metaCoreUrl);
+        console.warn(`[webdav-client] Failed to resolve WebDAV URL from ${metaCoreUrl}: ${error instanceof Error ? error.message : String(error)}`);
+        return null;
+    }
+}

test.sh

@@ -0,0 +1,93 @@
+#!/bin/bash
+# =============================================================================
+# Still Extractor Plugin Test Runner
+#
+# Runs integration tests inside a Docker container with FFprobe available.
+# Usage:
+#   ./test.sh              # Build and run tests
+#   ./test.sh --no-cache   # Rebuild without cache
+#   ./test.sh --shell      # Start shell in test container for debugging
+# =============================================================================
+
+set -e
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+cd "$SCRIPT_DIR"
+
+IMAGE_NAME="metamesh-plugin-still-extractor-test"
+DOCKERFILE="Dockerfile.test"
+
+# Parse arguments
+NO_CACHE=""
+SHELL_MODE=""
+
+for arg in "$@"; do
+    case $arg in
+        --no-cache)
+            NO_CACHE="--no-cache"
+            ;;
+        --shell)
+            SHELL_MODE=1
+            ;;
+        --help|-h)
+            echo "Usage: $0 [OPTIONS]"
+            echo ""
+            echo "Options:"
+            echo "  --no-cache   Rebuild Docker image without cache"
+            echo "  --shell      Start interactive shell in test container"
+            echo "  --help       Show this help message"
+            exit 0
+            ;;
+    esac
+done
+
+echo "=============================================="
+echo "  Still Extractor Plugin Test Runner"
+echo "=============================================="
+echo ""
+
+# Check if Docker is available
+if ! command -v docker &> /dev/null; then
+    echo "ERROR: Docker is not installed or not in PATH"
+    exit 1
+fi
+
+# Build the test image
+echo "[1/2] Building test image..."
+docker build $NO_CACHE -f "$DOCKERFILE" -t "$IMAGE_NAME" .
+
+if [ -n "$SHELL_MODE" ]; then
+    echo ""
+    echo "[2/2] Starting interactive shell..."
+    echo "      Run 'npm test' to execute tests"
+    echo ""
+    docker run --rm -it \
+        -v "$SCRIPT_DIR/test:/app/test:ro" \
+        -v "$SCRIPT_DIR/src:/app/src:ro" \
+        "$IMAGE_NAME" \
+        /bin/bash
+else
+    echo ""
+    echo "[2/2] Running tests..."
+    echo ""
+
+    # Run tests and capture exit code
+    docker run --rm \
+        -e CI=true \
+        "$IMAGE_NAME"
+
+    EXIT_CODE=$?
+
+    echo ""
+    if [ $EXIT_CODE -eq 0 ]; then
+        echo "=============================================="
+        echo "  All tests passed!"
+        echo "=============================================="
+    else
+        echo "=============================================="
+        echo "  Tests failed (exit code: $EXIT_CODE)"
+        echo "=============================================="
+    fi
+
+    exit $EXIT_CODE
+fi

test/fixtures/generate-test-fixtures.sh

@@ -0,0 +1,53 @@
+#!/bin/bash
+# Generate test videos for still-extractor integration tests.
+# Run inside the test container (ffmpeg required).
+
+set -e
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+cd "$SCRIPT_DIR"
+
+echo "Generating test fixtures..."
+
+# 1. Plain colourful video — every candidate offset should yield a usable frame.
+if [ ! -f "color.mp4" ]; then
+    echo "Creating color.mp4..."
+    ffmpeg -y -f lavfi -i testsrc=duration=10:size=320x240:rate=24 \
+           -c:v libx264 -preset ultrafast -crf 28 -pix_fmt yuv420p \
+           color.mp4
+fi
+
+# 2. Six seconds of black, then picture. 20s total, so the 20% candidate (4s)
+#    lands in the black head and must be rejected in favour of a later one.
+if [ ! -f "black-head.mp4" ]; then
+    echo "Creating black-head.mp4..."
+    ffmpeg -y -f lavfi -i "color=c=black:size=320x240:duration=6:rate=24" \
+           -c:v libx264 -preset ultrafast -crf 28 -pix_fmt yuv420p black_part.mp4
+    ffmpeg -y -f lavfi -i testsrc=duration=14:size=320x240:rate=24 \
+           -c:v libx264 -preset ultrafast -crf 28 -pix_fmt yuv420p color_part.mp4
+    printf "file 'black_part.mp4'\nfile 'color_part.mp4'\n" > concat.txt
+    ffmpeg -y -f concat -safe 0 -i concat.txt -c copy black-head.mp4
+    rm -f black_part.mp4 color_part.mp4 concat.txt
+fi
+
+# 3. Video carrying attached cover art LARGER than the video itself — the
+#    stream-selection trap. ffprobe reports the cover as codec_type=video.
+if [ ! -f "cover-art.mp4" ]; then
+    echo "Creating cover-art.mp4..."
+    ffmpeg -y -f lavfi -i "color=c=red:size=600x900:duration=1:rate=1" -frames:v 1 cover.png
+    ffmpeg -y -i color.mp4 -i cover.png \
+           -map 0:v -map 1 -c copy -disposition:v:1 attached_pic \
+           cover-art.mp4
+    rm -f cover.png
+fi
+
+# 4. Audio-only file — nothing to extract.
+if [ ! -f "audio-only.mp3" ]; then
+    echo "Creating audio-only.mp3..."
+    ffmpeg -y -f lavfi -i sine=frequency=440:duration=2 \
+           -c:a libmp3lame -b:a 128k \
+           audio-only.mp3
+fi
+
+echo "Test fixtures generated:"
+ls -la *.mp4 *.mp3 2>/dev/null || true

test/still.test.ts

@@ -0,0 +1,284 @@
+/**
+ * Still Extractor Plugin Tests
+ *
+ * Pure helpers run anywhere; the extraction tests need ffmpeg and the
+ * generated fixtures, so they run in the test container (./test.sh).
+ */
+
+import { describe, it, expect, beforeAll } from 'vitest';
+import { execSync } from 'child_process';
+import { existsSync, mkdirSync } from 'fs';
+import path from 'path';
+import { fileURLToPath } from 'url';
+
+import {
+    manifest,
+    process as processFile,
+    candidateOffsets,
+    frameStats,
+    isUsableFrame,
+    sanitizeFilename,
+    stillFilename,
+    computeMidHash256FromBuffer,
+    selectPrimaryVideoStream,
+    extractStill,
+    grabFrame,
+} from '../src/plugin.js';
+import type { CallbackPayload } from '../src/types.js';
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+const FIXTURES = path.join(__dirname, 'fixtures');
+const TEMP = '/tmp/still-extractor-test';
+
+function hasFfmpeg(): boolean {
+    try {
+        execSync('ffmpeg -version', { stdio: 'ignore' });
+        return true;
+    } catch {
+        return false;
+    }
+}
+
+function fixture(name: string): string {
+    return path.join(FIXTURES, name);
+}
+
+/** Build the `stream/{n}` table exactly the way the ffmpeg plugin writes it. */
+function streamTableFor(file: string): Record<string, string> {
+    const probe = JSON.parse(
+        execSync(`ffprobe -v quiet -print_format json -show_streams "${file}"`, { encoding: 'utf-8' })
+    ) as { streams: Array<Record<string, unknown>> };
+
+    const table: Record<string, string> = {};
+    let n = 0;
+    for (const s of probe.streams) {
+        if (s.codec_type !== 'video' && s.codec_type !== 'audio' && s.codec_type !== 'subtitle') continue;
+        const entry: Record<string, unknown> = { type: s.codec_type };
+        if (s.codec_name) entry.codec = String(s.codec_name);
+        if (s.index != null) entry.index = s.index;
+        if (s.width) entry.width = s.width;
+        if (s.height) entry.height = s.height;
+        // The ffmpeg plugin drops avg_frame_rate when it is "0/0" — the very
+        // signal we lean on to spot attached cover art.
+        if (s.avg_frame_rate && s.avg_frame_rate !== '0/0') entry.frameRate = String(s.avg_frame_rate);
+        table[`stream/${n}`] = JSON.stringify(entry);
+        n++;
+    }
+    return table;
+}
+
+const ffmpegAvailable = hasFfmpeg();
+const fixturesReady = existsSync(fixture('color.mp4'));
+
+describe('manifest', () => {
+    it('declares its dependencies and queue', () => {
+        expect(manifest.id).toBe('still-extractor');
+        expect(manifest.dependencies).toEqual(['file-info', 'ffmpeg']);
+        expect(manifest.defaultQueue).toBe('background');
+        expect(manifest.schema?.still).toBeDefined();
+    });
+
+    it('does not advertise writing poster or stillPath', () => {
+        const keys = Object.keys(manifest.schema ?? {});
+        expect(keys).toEqual(['still']);
+    });
+});
+
+describe('candidateOffsets', () => {
+    it('spreads candidates through the middle of the file', () => {
+        expect(candidateOffsets(100, [20, 45, 70])).toEqual([20, 45, 70]);
+    });
+
+    it('keeps away from both ends', () => {
+        const offsets = candidateOffsets(10, [1, 50, 99]);
+        for (const t of offsets) {
+            expect(t).toBeGreaterThanOrEqual(2);
+            expect(t).toBeLessThanOrEqual(8);
+        }
+    });
+
+    it('falls back to a blind attempt when duration is unknown', () => {
+        expect(candidateOffsets(undefined)).toEqual([10, 0]);
+        expect(candidateOffsets(0)).toEqual([10, 0]);
+    });
+
+    it('takes the midpoint of a very short clip', () => {
+        expect(candidateOffsets(3)).toEqual([1.5]);
+    });
+
+    it('deduplicates offsets that clamp onto each other', () => {
+        const offsets = candidateOffsets(6, [10, 12, 14]);
+        expect(new Set(offsets).size).toBe(offsets.length);
+    });
+});
+
+describe('frameStats / isUsableFrame', () => {
+    it('measures a flat buffer as zero-variance', () => {
+        const stats = frameStats(Buffer.alloc(1024, 128));
+        expect(stats.mean).toBe(128);
+        expect(stats.stddev).toBe(0);
+    });
+
+    it('rejects black, white and flat frames', () => {
+        expect(isUsableFrame({ mean: 2, stddev: 1 })).toBe(false);    // black
+        expect(isUsableFrame({ mean: 252, stddev: 1 })).toBe(false);  // blown out
+        expect(isUsableFrame({ mean: 128, stddev: 2 })).toBe(false);  // flat grey
+    });
+
+    it('accepts a frame with real detail', () => {
+        expect(isUsableFrame({ mean: 110, stddev: 45 })).toBe(true);
+    });
+});
+
+describe('filenames', () => {
+    it('strips path-hostile characters', () => {
+        expect(sanitizeFilename('a/b:c*d?')).toBe('abcd');
+    });
+
+    it('carries the source CID so two files cannot collide', () => {
+        const a = stillFilename('/files/watch/Show/episode.mkv', 'bafkreiaaaaaaaaaaaa111111');
+        const b = stillFilename('/files/watch/Other/episode.mkv', 'bafkreiaaaaaaaaaaaa222222');
+        expect(a).not.toBe(b);
+        expect(a.endsWith('_still.jpg')).toBe(true);
+        expect(a.startsWith('episode[')).toBe(true);
+    });
+});
+
+describe('computeMidHash256FromBuffer', () => {
+    // Vector produced by packages/meta-hash's own computeMidHash256Sync over a
+    // file holding exactly this string. This function is a hand-rolled copy of
+    // that algorithm; the vector is what pins the copy to the original.
+    it('matches meta-hash for a known buffer', () => {
+        const cid = computeMidHash256FromBuffer(Buffer.from('metamesh-still-extractor-cid-vector'));
+        expect(cid).toBe('bagacbabaecybg7wcyxl7su3dvjleuwgwil5tgeoybrwc35jasqtywb6bnjzk4');
+    });
+});
+
+describe('selectPrimaryVideoStream', () => {
+    it('returns null when there is no video stream', () => {
+        expect(selectPrimaryVideoStream({
+            'stream/0': JSON.stringify({ type: 'audio', index: 0, codec: 'aac' }),
+        })).toBeNull();
+        expect(selectPrimaryVideoStream(undefined)).toBeNull();
+        expect(selectPrimaryVideoStream({})).toBeNull();
+    });
+
+    it('reads the flattened `stream` array form too', () => {
+        const picked = selectPrimaryVideoStream({
+            stream: JSON.stringify([
+                JSON.stringify({ type: 'audio', index: 0 }),
+                JSON.stringify({ type: 'video', index: 1, width: 1920, height: 1080, codec: 'h264', frameRate: '24/1' }),
+            ]),
+        } as unknown as Record<string, string>);
+        expect(picked?.index).toBe(1);
+    });
+
+    it('prefers the larger of two real video streams', () => {
+        const picked = selectPrimaryVideoStream({
+            'stream/0': JSON.stringify({ type: 'video', index: 0, width: 640, height: 480, codec: 'h264', frameRate: '24/1' }),
+            'stream/1': JSON.stringify({ type: 'video', index: 1, width: 1920, height: 1080, codec: 'h264', frameRate: '24/1' }),
+        });
+        expect(picked?.index).toBe(1);
+    });
+
+    it('ignores a bigger cover art stream in favour of the moving picture', () => {
+        const picked = selectPrimaryVideoStream({
+            'stream/0': JSON.stringify({ type: 'video', index: 0, width: 320, height: 240, codec: 'h264', frameRate: '24/1' }),
+            // attached_pic: no frameRate, still-image codec, but much larger
+            'stream/1': JSON.stringify({ type: 'video', index: 1, width: 600, height: 900, codec: 'mjpeg' }),
+        });
+        expect(picked?.index).toBe(0);
+    });
+
+    it('still returns something when nothing looks like moving video', () => {
+        const picked = selectPrimaryVideoStream({
+            'stream/0': JSON.stringify({ type: 'video', index: 0, width: 600, height: 900, codec: 'mjpeg' }),
+        });
+        expect(picked?.index).toBe(0);
+    });
+
+    it.skipIf(!ffmpegAvailable || !fixturesReady)(
+        'picks the film, not the cover, on a real file',
+        () => {
+            const picked = selectPrimaryVideoStream(streamTableFor(fixture('cover-art.mp4')));
+            expect(picked).not.toBeNull();
+            expect(picked!.width).toBe(320);
+            expect(picked!.height).toBe(240);
+        }
+    );
+});
+
+describe.skipIf(!ffmpegAvailable || !fixturesReady)('extraction', () => {
+    beforeAll(() => {
+        mkdirSync(TEMP, { recursive: true });
+    });
+
+    it('extracts a usable frame from a colourful video', async () => {
+        const result = await extractStill(fixture('color.mp4'), 0, 10, TEMP);
+        expect(result).not.toBeNull();
+        expect(result!.jpeg.subarray(0, 2)).toEqual(Buffer.from([0xff, 0xd8])); // JPEG SOI
+        expect(isUsableFrame(result!.stats)).toBe(true);
+    });
+
+    it('skips past a black head to a later offset', async () => {
+        // 20s file, 6s of black: the 20% candidate (4s) is black and must lose.
+        const result = await extractStill(fixture('black-head.mp4'), 0, 20, TEMP);
+        expect(result).not.toBeNull();
+        expect(result!.offsetSec).toBeGreaterThan(6);
+        expect(isUsableFrame(result!.stats)).toBe(true);
+    });
+
+    it('returns null for a file with nothing to decode', async () => {
+        const frame = await grabFrame(fixture('audio-only.mp3'), 0, 1, path.join(TEMP, 'nope.jpg'));
+        expect(frame).toBeNull();
+    });
+
+    it('scales the frame down to the configured width', async () => {
+        const result = await extractStill(fixture('color.mp4'), 0, 10, TEMP);
+        expect(result).not.toBeNull();
+        // Source is 320x240, below the 640 cap, so it must come back untouched.
+        expect(result!.jpeg.length).toBeGreaterThan(0);
+        expect(result!.jpeg.length).toBeLessThan(200_000);
+    });
+});
+
+describe('process - skip logic', () => {
+    const collect = () => {
+        const seen: CallbackPayload[] = [];
+        return { seen, cb: async (p: CallbackPayload) => { seen.push(p); } };
+    };
+
+    const req = (existingMeta: Record<string, string>) => ({
+        taskId: 't1',
+        cid: 'bafkreitest',
+        filePath: '/files/watch/test.mkv',
+        callbackUrl: 'http://localhost/callback',
+        // Unreachable on purpose: every case here must bail before any I/O.
+        metaCoreUrl: 'http://127.0.0.1:9',
+        existingMeta,
+    });
+
+    it('skips non-video files', async () => {
+        const { seen, cb } = collect();
+        await processFile(req({ fileType: 'image' }), cb);
+        expect(seen[0].status).toBe('skipped');
+        expect(seen[0].reason).toBe('Not a video file');
+    });
+
+    it('skips a record that already has a still', async () => {
+        const { seen, cb } = collect();
+        await processFile(req({ fileType: 'video', still: 'bafkreialready' }), cb);
+        expect(seen[0].status).toBe('skipped');
+        expect(seen[0].reason).toBe('Still already present');
+    });
+
+    it('skips when there is no video stream', async () => {
+        const { seen, cb } = collect();
+        await processFile(
+            req({ fileType: 'video', 'stream/0': JSON.stringify({ type: 'audio', index: 0 }) }),
+            cb
+        );
+        expect(seen[0].status).toBe('skipped');
+        expect(seen[0].reason).toBe('No video stream');
+    });
+});

tsconfig.json

@@ -0,0 +1,18 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "NodeNext",
+    "moduleResolution": "NodeNext",
+    "lib": ["ES2022"],
+    "outDir": "./dist",
+    "rootDir": "./src",
+    "strict": true,
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "forceConsistentCasingInFileNames": true,
+    "declaration": true,
+    "sourceMap": true
+  },
+  "include": ["src/**/*"],
+  "exclude": ["node_modules", "dist"]
+}

vitest.config.ts

@@ -0,0 +1,17 @@
+import { defineConfig } from 'vitest/config';
+
+export default defineConfig({
+    test: {
+        globals: true,
+        environment: 'node',
+        include: ['test/**/*.test.ts'],
+        testTimeout: 30000, // 30s timeout for FFprobe tests
+        hookTimeout: 60000, // 60s for setup/teardown
+        coverage: {
+            provider: 'v8',
+            reporter: ['text', 'json', 'html'],
+            include: ['src/**/*.ts'],
+            exclude: ['src/types.ts'],
+        },
+    },
+});