get_rotation_filter() {
    local f="$1"
    local rotation
    rotation=$(exiftool -Rotation -n "$f" | awk '{print $3}')
    # echo $rotation $f >> "rotations.txt"
    case "$rotation" in
        # 90)  echo "transpose=1" ;;
        # 270) echo "transpose=2" ;;
        # 180) echo "hflip,vflip" ;;
        # *)   echo "" ;;
        *) echo "transpose=1" ;;
    esac
}
export -f get_rotation_filter

reencode_with_rotation() {
    local src="$1"
    local dst="$2"
    local filter
    filter="$(get_rotation_filter "$src")"

    if [ -n "$filter" ]; then
        echo "  Correction d’orientation (rotation=${filter})"
        if ffmpeg -encoders 2>/dev/null | grep -q 'h264_videotoolbox'; then
            ffmpeg -nostdin -i "$src" -vf "$filter" \
                -c:v h264_videotoolbox -b:v 5M -c:a aac -map_metadata -1 -y "$dst"
        else
            ffmpeg -nostdin -i "$src" -vf "$filter" \
                -c:v libx264 -preset fast -crf 18 -c:a aac -map_metadata -1 -y "$dst"
        fi
    else
        # Pas de rotation → simple copie (ou réencodage minimal)
        if ffmpeg -y -i "$src" -c copy -map 0 -movflags +faststart "$dst" < /dev/null 2>/dev/null; then
            :
        else
            if ffmpeg -encoders 2>/dev/null | grep -q 'h264_videotoolbox'; then
                ffmpeg -nostdin -i "$src" \
                    -c:v h264_videotoolbox -b:v 5M -c:a aac -map_metadata -1 -y "$dst"
            else
                ffmpeg -nostdin -i "$src" \
                    -c:v libx264 -preset fast -crf 18 -c:a aac -map_metadata -1 -y "$dst"
            fi
        fi
    fi
}
export -f reencode_with_rotation