fix: resolve 'auto' encoder to detected hardware and add VAAPI drivers to Dockerfile

Dockerfile

@@ -2,7 +2,14 @@ FROM node:20-alpine
 
 # Install build dependencies for better-sqlite3 and FFmpeg for streaming
 # Using system FFmpeg instead of ffmpeg-static for better Docker DNS compatibility
-RUN apk add --no-cache python3 make g++ ffmpeg
+# Hardware acceleration packages:
+#   - mesa-va-gallium: AMD VAAPI (Radeon/Vega)
+#   - intel-media-driver: Intel VAAPI/QSV (newer Intel GPUs)
+#   - libva-intel-driver: Intel VAAPI (older Intel GPUs, Haswell-Skylake)
+#   - libva-utils: vainfo tool for debugging
+# Note: NVIDIA requires nvidia-container-toolkit on host + --gpus flag
+RUN apk add --no-cache python3 make g++ ffmpeg \
+    mesa-va-gallium intel-media-driver libva-intel-driver libva-utils
 
 WORKDIR /app
 

server/services/transcodeSession.js

@@ -17,6 +17,7 @@ const path = require('path');
 const fs = require('fs').promises;
 const crypto = require('crypto');
 const EventEmitter = require('events');
+const hwDetect = require('./hwDetect');
 
 // Session storage
 const sessions = new Map();
@@ -166,9 +167,16 @@ class TranscodeSession extends EventEmitter {
      */
     buildFFmpegArgs() {
         const segmentPattern = path.join(this.dir, 'seg%04d.m4s');
-        const encoder = this.options.hwEncoder || 'software';
         const videoMode = this.options.videoMode || 'encode';
 
+        // Resolve 'auto' encoder to detected hardware, fallback to software
+        let encoder = this.options.hwEncoder || 'software';
+        if (encoder === 'auto') {
+            const hwCaps = hwDetect.getCapabilities();
+            encoder = hwCaps?.recommended || 'software';
+            console.log(`[TranscodeSession ${this.id}] Auto encoder resolved to: ${encoder}`);
+        }
+
         const args = [
             '-hide_banner',
             '-loglevel', 'warning',