Initial skill: tiktok-video-review with 14-frame extraction workflow

scripts/extract-frames.sh

@@ -0,0 +1,76 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+INPUT=""
+OUTDIR=""
+COUNT="14"
+
+while [[ $# -gt 0 ]]; do
+  case "$1" in
+    --input)
+      INPUT="$2"
+      shift 2
+      ;;
+    --outdir)
+      OUTDIR="$2"
+      shift 2
+      ;;
+    --count)
+      COUNT="$2"
+      shift 2
+      ;;
+    *)
+      echo "Unknown arg: $1" >&2
+      exit 1
+      ;;
+  esac
+done
+
+if [[ -z "$INPUT" || -z "$OUTDIR" ]]; then
+  echo "Usage: $0 --input <video.mp4> --outdir <dir> [--count 14]" >&2
+  exit 1
+fi
+
+if [[ ! -f "$INPUT" ]]; then
+  echo "Input file not found: $INPUT" >&2
+  exit 1
+fi
+
+mkdir -p "$OUTDIR"
+rm -f "$OUTDIR"/frame_*.jpg
+
+DURATION="$(ffprobe -v error -show_entries format=duration -of default=nokey=1:noprint_wrappers=1 "$INPUT")"
+
+python3 - "$INPUT" "$OUTDIR" "$COUNT" "$DURATION" <<'PY'
+import os
+import subprocess
+import sys
+
+inp, outdir, count_s, dur_s = sys.argv[1:]
+count = max(1, int(count_s))
+duration = float(dur_s)
+
+if duration <= 0:
+    print("Invalid duration", file=sys.stderr)
+    sys.exit(1)
+
+# Centered uniform sampling across full duration.
+step = duration / count
+times = [min(duration - 0.01, (i + 0.5) * step) for i in range(count)]
+
+for idx, t in enumerate(times, start=1):
+    out = os.path.join(outdir, f"frame_{idx:02d}.jpg")
+    cmd = [
+        "ffmpeg", "-y",
+        "-ss", f"{t:.6f}",
+        "-i", inp,
+        "-frames:v", "1",
+        "-q:v", "2",
+        out,
+    ]
+    subprocess.run(cmd, check=True, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
+
+print(f"Extracted {count} frames to {outdir}")
+PY
+
+ls -1 "$OUTDIR"/frame_*.jpg