#!/bin/bash
# Normalize video to Linear Void required profile.
# Output: H.264/AAC, 30fps constant, 2s keyframes, yuv420p, 48kHz audio.
# Usage: ./normalize.sh <input> [output]
set -e

INPUT="$1"
if [ -z "$INPUT" ]; then
  echo "Usage: $0 <input-file> [output-file]"
  echo "  Normalizes video to Linear Void profile: H.264/AAC, 30fps, 2s keyframes"
  exit 1
fi

if [ ! -f "$INPUT" ]; then
  echo "Error: input file not found: $INPUT"
  exit 1
fi

OUTPUT="${2:-${INPUT%.*}-normalized.mp4}"
CRF="${NORMALIZE_CRF:-21}"
PRESET="${NORMALIZE_PRESET:-medium}"
AUDIO_BITRATE="${NORMALIZE_AUDIO_BITRATE:-160k}"

echo "=== Linear Void Video Normalization ==="
echo "  Input:       $INPUT ($(du -h "$INPUT" | cut -f1))"
echo "  Output:      $OUTPUT"
echo "  CRF:         $CRF"
echo "  Preset:      $PRESET"
echo "  Audio rate:  $AUDIO_BITRATE"
echo ""

# Probe input
echo "--- Input Properties ---"
ffprobe -v error -show_entries stream=codec_name,width,height,r_frame_rate,pix_fmt,sample_rate,channels \
        -of default=noprint_wrappers=1 "$INPUT" 2>&1
echo ""

# Normalize
echo "--- Normalizing ---"
ffmpeg -y -i "$INPUT" \
  -c:v libx264 -preset "$PRESET" -crf "$CRF" \
  -r 30 -g 60 -keyint_min 60 -sc_threshold 0 \
  -pix_fmt yuv420p \
  -c:a aac -b:a "$AUDIO_BITRATE" -ar 48000 -ac 2 \
  -movflags +faststart \
  "$OUTPUT"

echo ""
echo "--- Output Properties ---"
ffprobe -v error -show_entries stream=codec_name,width,height,r_frame_rate,pix_fmt,sample_rate,channels \
        -of default=noprint_wrappers=1 "$OUTPUT" 2>&1
echo ""

echo "=== Normalization Complete ==="
echo "  Output: $OUTPUT ($(du -h "$OUTPUT" | cut -f1))"
echo ""
echo "Verify with: ffprobe -v error -show_entries stream=codec_name,r_frame_rate,pix_fmt -of default=noprint_wrappers=1 $OUTPUT"