#!/bin/bash
# Concatenate extracted segments into assembled teaser
# Usage: ./concat_segments.sh

set -euo pipefail

OUTDIR="segments"
OUTPUT="assembled.mp4"

echo "==> Building concat list"
cat > concat.txt <<EOF
file '$OUTDIR/problem.mp4'
file '$OUTDIR/value_prop.mp4'
file '$OUTDIR/numbers.mp4'
file '$OUTDIR/demo_payoff.mp4'
file '$OUTDIR/review_bar.mp4'
EOF

echo "==> Concatenating segments"
ffmpeg -y -f concat -safe 0 -i concat.txt -c copy "$OUTPUT"

echo "==> Normalizing final audio"
ffmpeg -y -i "$OUTPUT" -af loudnorm=I=-16:TP=-1.5:LRA=11 -c:v copy "normalized.mp4"
mv normalized.mp4 "$OUTPUT"

rm concat.txt

echo "==> Done: $OUTPUT"
ffprobe -v quiet -show_entries format=duration -of default=noprint_wrappers=1 "$OUTPUT"