Files
manga-recap-pipeline/scripts/analyze_video_frames.sh
T
kami ff6a512630 Reconstruct repo from Claude Code + codex transcripts
Working tree (including .git) was lost to an rm. Rebuilt by replaying Write/Edit/
Read/attachment events from 25 Claude sessions and 22 successful codex apply_patch
blocks into one timestamp-ordered timeline.

Verified against ground truth recorded in the transcripts: wc -l on 10 files and
ls -l on 5 files at 2026-07-18T13:13:44Z both match exactly; 18 files are
byte-identical to their newest ~/.claude/file-history blob.

See HANDOFF.md for sources, gaps, and how to rebuild .venv.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-08-11 02:42:41 +04:00

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#!/usr/bin/env bash
# Turn a video into timestamped contact sheets and scene-change frames for visual analysis.
# Optional --window START:DURATION arguments create dense 10-fps sheets around transitions.
set -euo pipefail
usage() {
cat <<'EOF'
Usage:
scripts/analyze_video_frames.sh VIDEO [OUTPUT_DIR] [--window START:DURATION ...]
Examples:
scripts/analyze_video_frames.sh chapter.mp4
scripts/analyze_video_frames.sh chapter.mp4 /tmp/chapter-analysis \
--window 5.8:2.2 --window 15.8:2.5
Outputs:
overview-001.jpg ... 2-fps timestamped contact sheets
scenes/scene-001.jpg ... frames selected by scene-change score
scene-timestamps.txt scene-change timestamps from FFmpeg showinfo
window-START.jpg 10-fps contact sheet for each requested window
Environment overrides:
OVERVIEW_FPS=2 SCENE_THRESHOLD=0.18 WINDOW_FPS=10
EOF
}
if [ "$#" -lt 1 ] || [ "${1:-}" = "-h" ] || [ "${1:-}" = "--help" ]; then
usage
exit $([ "$#" -lt 1 ] && echo 1 || echo 0)
fi
video=$1
shift
if [ ! -f "$video" ]; then
echo "video not found: $video" >&2
exit 1
fi
if [ "$#" -gt 0 ] && [[ $1 != --* ]]; then
output_dir=$1
shift
else
base=$(basename "$video")
output_dir="/tmp/${base%.*}-frames"
fi
overview_fps=${OVERVIEW_FPS:-2}
scene_threshold=${SCENE_THRESHOLD:-0.18}
window_fps=${WINDOW_FPS:-10}
windows=()
while [ "$#" -gt 0 ]; do
case "$1" in
--window)
[ "$#" -ge 2 ] || { echo "--window needs START:DURATION" >&2; exit 2; }
windows+=("$2")
shift 2
;;
*)
echo "unknown argument: $1" >&2
usage >&2
exit 2
;;
esac
done
mkdir -p "$output_dir/scenes"
# Six-by-six sheets keep individual frames readable while allowing videos of arbitrary length:
# tile emits additional overview-NNN images after every 36 sampled frames.
ffmpeg -hide_banner -loglevel error -y -i "$video" \
-vf "fps=${overview_fps},scale=320:-1,drawtext=text='%{pts\\:hms}':x=8:y=8:fontsize=20:fontcolor=yellow:borderw=2,tile=6x6:padding=4:margin=4" \
-fps_mode vfr "$output_dir/overview-%03d.jpg"
# Keep stderr because showinfo reports the original timestamps there.
ffmpeg -hide_banner -y -i "$video" \
-vf "select='gt(scene,${scene_threshold})',showinfo" -fps_mode vfr \
"$output_dir/scenes/scene-%03d.jpg" 2>"$output_dir/scene-showinfo.log" || true
sed -n 's/.*pts_time:\([^ ]*\).*/\1/p' "$output_dir/scene-showinfo.log" \
>"$output_dir/scene-timestamps.txt"
for window in "${windows[@]}"; do
start=${window%%:*}
duration=${window#*:}
if [ "$start" = "$window" ] || [ -z "$start" ] || [ -z "$duration" ]; then
echo "invalid window '$window'; expected START:DURATION" >&2
exit 2
fi
safe_start=${start//./_}
# A 5x5 sheet covers 2.5 seconds at the default 10 fps. Longer windows naturally emit more sheets.
ffmpeg -hide_banner -loglevel error -y -ss "$start" -t "$duration" -i "$video" \
-vf "fps=${window_fps},scale=320:-1,drawtext=text='%{pts\\:hms}':x=6:y=6:fontsize=18:fontcolor=yellow:borderw=2,tile=5x5:padding=3:margin=3" \
-fps_mode vfr "$output_dir/window-${safe_start}-%03d.jpg"
done
echo "video analysis frames: $output_dir"