#!/bin/bash
# https://trac.ffmpeg.org/wiki/How%20to%20speed%20up%20/%20slow%20down%20a%20video
# https://github.com/mozilla/TTS
#

if [ -z "$1" ]; then 
    echo usage: $0 \"filename\" [tempo]
        exit
fi

FILE=$1
STR=`cat $FILE`
MODEL="tts_models/en/jenny/jenny"
TEMPO=1.0

if [ -z "$2" ]; then
    TEMPO=$TEMPO
else
    TEMPO=$2
fi

tts --text "$STR" --model_name "$MODEL" && \
ffmpeg -i tts_output.wav -filter:a "atempo=$TEMPO" -vn ffmpeg_output.wav -y && \
ffmpeg -i ffmpeg_output.wav -acodec mp3 $FILE.mp3 -y && \
ffplay $FILE.mp3 -nodisp -autoexit