convert-to-av1.sh

#!/bin/bash

# Default pixel format
pixel_format="yuv420p10le"

# Parse command line options
while getopts ":pix_fmt:" opt; do
  case ${opt} in
    p )
      pixel_format="$OPTARG"
      ;;
    \? )
      echo "Usage: $0 [-pix_fmt <pixel_format>] [<input_file>]"
      exit 1
      ;;
  esac
done
shift $((OPTIND -1))

# Check if an input file argument is provided
if [ $# -eq 1 ]; then
    input_file="$1"
    # Check if the file exists and is a regular file
    if [ ! -f "$input_file" ]; then
        echo "Input file does not exist or is not a regular file: $input_file"
        exit 1
    fi
    files=("$input_file")
else
    # No filename provided, process all MKV files in the folder
    files=(*.mkv)
fi

# Loop through all MKV files
for file in "${files[@]}"; do
    # Get the filename without extension
    filename=$(basename "$file" .mkv)
    echo "Name of the file without extension: "$filename""
    # Check if the output file already exists
    if [ ! -f "${filename}-AV1.mkv" ]; then
        # Define the output filename
        output="${filename}-AV1.mkv"
        # Run ffmpeg command
        echo "About to convert file named "$file""
        ffmpeg -i "$file" -pix_fmt "$pixel_format" -map 0 -c:v libsvtav1 -crf 35 -preset 6 -svtav1-params tune=0 -g 240 -c:a libopus -b:a 128k -ac 2 -c:s copy "$output"
        echo "Conversion complete for "$file""
    else
        echo "Output file ${filename}-AV1.mkv already exists. Skipping conversion for $file"
    fi
done

Yo no borraría los ficheros originales hasta comprobar que todo está correcto. A mi m pasó que algún fichero tenía el audio con alguna información corrupta y el fichero final no tenía sonido y tuve que volver a convertirlo con otras opciones que no recuerdo.
Mejor borrar a mano.