Sweep/vgdeband: cap x264 at ENCODE_THREADS (2) so conversions stop starving Jellyfin and the live portal

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

bin/normalize-sweep.sh

@@ -29,6 +29,9 @@ FILL_GAPS_MS="${FILL_GAPS_MS:-0}"
 # Band removal re-encodes every stream that carried the timecode band. The raw (with band) is deleted after a
 # successful encode; KEEP_RAW_STREAMS=1 keeps it in the hidden .src/ instead (doubles disk per night).
 KEEP_RAW_STREAMS="${KEEP_RAW_STREAMS:-0}"
+# Encoder threads for every re-encode (clips and streams). 2 leaves the box responsive for Jellyfin/live viewers;
+# conversions take longer. systemd Environment=ENCODE_THREADS=... to change.
+ENCODE_THREADS="${ENCODE_THREADS:-2}"
 MAX_W=2560; MAX_H=1440; MAX_FPS=60
 exec 9>"${LOCK_FILE:-/run/lock/normalize-sweep.lock}"
 flock -n 9 || exit 0
@@ -166,7 +169,7 @@ PYEOF
     if (( live )) && [[ $reason != *audio=* ]]; then aargs=(-c:a copy); fi
     nice -n 15 ionice -c 3 ffmpeg -nostdin -hide_banner -loglevel error -y -i "$src" \
       -map 0:v:0 -map '0:a?' \
-      -c:v libx264 -preset veryfast -crf 18 -maxrate 30M -bufsize 60M -pix_fmt yuv420p -profile:v high \
+      -c:v libx264 -preset veryfast -crf 18 -maxrate 30M -bufsize 60M -pix_fmt yuv420p -profile:v high -threads "$ENCODE_THREADS" \
       -vf "$vf" -fps_mode "$fpsmode" "${fpsargs[@]}" \
       "${aargs[@]}" \
       "${tcargs[@]}" -movflags +faststart -f mp4 "$tmp"