preparing defense content pushing

paper/defense/manim/scripts/ffmpeg_concat_defense.sh

@@ -0,0 +1,25 @@
+#!/usr/bin/env bash
+# Concatenate rendered defense scenes (all under media/videos/defense/<quality>/).
+# Usage from paper/defense/manim after: ./render_defense full --quality qh
+#   ./scripts/ffmpeg_concat_defense.sh qh
+set -euo pipefail
+QUALITY="${1:-qm}"
+ROOT="$(cd "$(dirname "$0")/.." && pwd)"
+LIST="$(mktemp)"
+trap 'rm -f "$LIST"' EXIT
+DIR="$ROOT/media/videos/defense/$QUALITY"
+
+while IFS= read -r line || [[ -n "$line" ]]; do
+  [[ "$line" =~ ^#.*$ || -z "${line// }" ]] && continue
+  name="$line"
+  f="$DIR/${name}.mp4"
+  if [[ ! -f "$f" ]]; then
+    echo "missing: $f" >&2
+    exit 1
+  fi
+  echo "file '$f'" >>"$LIST"
+done <"$ROOT/defense_scene_order.txt"
+
+OUT="$ROOT/media/defense_rehearsal_${QUALITY}.mp4"
+ffmpeg -y -f concat -safe 0 -i "$LIST" -c copy "$OUT"
+echo "wrote $OUT"