wav audio file to ogg format

wav2ogg.sh

#!/bin/bash

# Usage:
#   AUDIO_PATH=~/Desktop/working/dir/path sh ./wav2ogg.sh
#
# @see [FFmpeg](https://ffmpeg.org/)

set -Ceuo pipefail

cd "$(dirname "$0")"

AUDIO_PATH="${AUDIO_PATH:-/tmp/audio}"

AUDIO_CHANNELS="2"
AUDIO_SAMPLING_FREQUENCY="44100"
AUDIO_BITRATE="128k"
AUDIO_CODEC="libvorbis"
OGG_EXT=".ogg"

function confirm() {
    local message default reply

    message="${1}"
    echo "${message}"

    default="No"

    read -r reply

    if [[ -z "${reply}" ]]; then
        reply="${default}"
    fi

    case "${reply}" in
        Y*|y*) return 0 ;;
        N*|n*) return 1 ;;
        *) return 2 ;;
    esac
}

function bye() {
    echo "Bye."
    return 1
}

function raise() {
    local error

    error="${1}"
    echo "${error}" 1>&2
    return 1
}

if [ ! -e "${AUDIO_PATH}" ] || [ ! -d "${AUDIO_PATH}" ]; then
    raise 'The path to audio location does not exist.'
fi

echo "Audio files location: ${AUDIO_PATH}"

confirm "Is it OK to convert? [y/N]" || bye

ffmpeg -version >/dev/null 2>&1 || raise 'FFmpeg is not installed'

for file in $(ls "${AUDIO_PATH}" | grep ".*\.wav$"); do
    ffmpeg -y -stats \
        -i "${AUDIO_PATH}/${file}" \
        -vn \
        -ac "${AUDIO_CHANNELS}" \
        -ar "${AUDIO_SAMPLING_FREQUENCY}" \
        -b:a "${AUDIO_BITRATE}" \
        -codec:a ${AUDIO_CODEC} \
        -f ogg "${AUDIO_PATH}/${file%.wav}${OGG_EXT}"
done;