#!/bin/bash

INPUT="$HOME/mount/Ripping/Lutz/noch zu rendern/Brücke nach Terabithia/A1_t00.mkv"
OUTPUT="${INPUT%.*}_deinterlaced.mp4"
LOGFILE=$(mktemp)

if [ ! -f "$INPUT" ]; then
  echo "Input file not found."
  exit 1
fi

# Step 1: Try runtime detection with idet
ffmpeg -hide_banner -vstats -nostats \
  -i "$INPUT" \
  -filter:v "format=yuv420p,idet" \
  -frames:v 500 \
  -an -f rawvideo -y /dev/null \
  2> "$LOGFILE"

TFF=$(grep -o 'TFF:[0-9]*' "$LOGFILE" | head -1 | cut -d: -f2)
BFF=$(grep -o 'BFF:[0-9]*' "$LOGFILE" | head -1 | cut -d: -f2)
PROG=$(grep -o 'Progressive:[0-9]*' "$LOGFILE" | head -1 | cut -d: -f2)
rm "$LOGFILE"

TFF=${TFF:-0}
BFF=${BFF:-0}
PROG=${PROG:-0}

echo "Detected via idet - Progressive: $PROG, TFF: $TFF, BFF: $BFF"

# Step 2: Fallback to metadata if no detection occurred
if [ "$((TFF + BFF + PROG))" -eq 0 ]; then
  echo "idet returned 0 frames — falling back to metadata..."
  FIELD_ORDER=$(ffprobe -v error -select_streams v:0 \
    -show_entries stream=field_order \
    -of default=noprint_wrappers=1:nokey=1 "$INPUT")

  case "$FIELD_ORDER" in
    tt|bb)
      echo "Field order is interlaced ($FIELD_ORDER)."
      INTERLACED=true
      ;;
    progressive|unknown|"")
      echo "Metadata says progressive or unknown."
      INTERLACED=false
      ;;
  esac
else
  INTERLACED=$((TFF + BFF > PROG))
fi

# Step 3: Skip or apply deinterlacing
if [ "$INTERLACED" = false ]; then
  echo "Video is progressive. No deinterlacing needed."
  exit 0
fi

echo "Video is interlaced. Proceeding with deinterlacing..."

# Step 4: Apply yadif
ffmpeg -i "$INPUT" \
  -vf "yadif=mode=1:parity=auto" \
  -c:v libx264 -preset slow -crf 18 -c:a copy \
  "$OUTPUT"