function av1encode
    if test (count $argv) -lt 1
        echo "Usage: av1encode <input-file> [crf] [preset]"
        return 1
    end

    set input $argv[1]
    set crf (varDefault $argv[2] 28)
    set preset (varDefault $argv[3] 6)

    set base (basename $input)
    set name (string replace -r '\.[^.]+$' '' $base)
    set output "$name.av1.mkv"

    echo "Encoding: $input -> $output (CRF $crf, preset $preset)..."

    ffmpeg -i "$input" \
        -map 0 \
        -c:v libsvtav1 -crf $crf -preset $preset \
        -c:a libopus \
        -c:s copy \
        -movflags +faststart \
        "$output"
end