Audiobook Generator. Takes a text file, splits it up into chunks, runs it through the Edge-TTS, combines the files into a single wav file, and then reencodes into an Opus files for minimum size/maximum quality.

generate_audiobook.sh

#!/bin/bash

# takes a text file and makes an audiobook of it ex:
# ./generate_audiobook.sh input_book.txt



# a few notes,

# first, you'll need to install edge-tts (pip3 install edge-tts), sox (sudo apt-get install sox), and
# opus (sudo apt-get install opus-tools)

# second, you'll have to get your ebook into txt format calibre is helpful for this. also, for example the
# time machine (https://www.gutenberg.org/files/35/35-0.txt) needs manual clean up of extra text, chapter listings,
# index, glossary, etc.

# third, below there's a variable for threads, that's how many simultaneious requests we make from edge-tts,
# 6 seems fastest on my machine, but try higher and see if it goes faster

# fourth, below there's a variable for 'chars_per_request' this changes the approximate number of charecters per
# file that get sent to edge-tts 2000-5000 seems like a good balance of size vs speed of request

threads=6
chars_per_request=2000

input=${1}

id=$(uuid)


cp "$input" "$id-$input.txt"

printf "$input to $id-$input.txt\n"

mkdir $id-audiobook
cd $id-audiobook

char_count=0
file_count=0

printf "\n\n\nsplitting book:\n\n"
while IFS= read -r line #this loop splits files into files with approximately the number of charecters in chars_per_request
do
  echo $line >> book_split_$( printf "%05d" $file_count).txt # add the line to the current output file
  char_count=$(( ${#line} + $char_count)) # add the count of the current line to the total charecter count
  if [ $char_count -gt $chars_per_request ] #if we've exceeded the charecters per request we'll reset the counters and increment the current file
  then
    printf "book_split_$( printf "%05d" $file_count).txt\n"
    file_count=$((file_count+1))
    char_count=0
  fi
done < "../$id-$input.txt"


if test -f "book_split_$( printf "%05d" $file_count).txt"; then #it's possible the splitting loop finished with the last file blank, we check for that here
  printf "book_split_$( printf "%05d" $file_count).txt\n"
fi

printf "\n\n\nproccessing tts:\n\n"

#find our split text files, and send them to edge-tts to be made into mp3s
find . -maxdepth 1  -type f -name "book_split*" -print0 | shuf | perl -pe 's/\n//gi' | xargs -t --verbose -0 -P $threads -I %  edge-tts --write-subtitles /dev/null -f % --voice en-US-SteffanNeural --write-media %.mp3

mkdir text-split
mv *.txt text-split

mkdir audio-files
mv *.mp3 audio-files

cd audio-files

printf "\n\n\ndecoding mp3s:\n\n"

#find all the mp3s and convert them to wav files for conversion (i was using ffmpeg for this, but it was introducing an odd chirping sound)
find *.mp3 -print0 | xargs -t --verbose -0 -P $threads -I %  lame --quiet --decode % 

printf "\n\n\nencoding opus:\n\n"

#sox combines the wav files and we pipe them into opus
sox $(ls *.wav | sort -n) -t wav - | opusenc --downmix-mono --bitrate 32 --vbr - ../../$id-$input-full.opus

rm *.wav