Freepbx Voicemail Transcription Script: Google Speech API

sendmail-gcloud

#!/bin/sh

# sendmail-gcloud
#
# Installation instructions
# Copy the content of this file to /usr/sbin/sendmail-gcloud
#
# Google Account
# ---------------
# Create an account, if you don't have yet, with Google Cloud. Free trials can be made at https://console.cloud.google.com/freetrial
# Within console.cloud.google.com search for Cloud Speech-to-Text API and enable it
#
# From the Linux command line on the FreePBX machine
# -------------------------------------------
# Follow steps 1 and 2 of the instructions on Google Cloud https://cloud.google.com/sdk/docs/downloads-yum
# Run the following commands on FreePBX;
#    cd /usr/sbin/
#    chown asterisk:asterisk sendmail-gcloud
#    chmod 744 sendmail-gcloud
#    chmod 777 /usr/bin/dos2unix
#
# Verify that you have the following (by simply running the command) and if not use yum install;
#    jq
#    sox
#    flac
#    dos2unix -V
# Ensure dos2unix is executable by the asterisk user (chmod 777 /usr/bin/dos2unix)
#
# Connect FreePBX to Google Cloud
#     su asterisk
#     gcloud auth login
# CLI will provide you a url. Copy that and paste it into your browser. Google will give you a verification code to copy. Paste it into the cli waiting for a verification code.
#
# Open FreePBX web interface
#     Go to Settings > Voicemail Admin > Settings > Email Config
#     Change Mail Command to: /usr/sbin/sendmail-gcloud
#     Submit and apply changes
#
# Original source created by N. Bernaerts: https://github.com/NicolasBernaerts/debian-scripts/tree/master/asterisk
# modified per: https://jrklein.com/2015/08/17/asterisk-voicemail-transcription-via-ibm-bluemix-speech-to-text-api/
# modified per: https://gist.github.com/lgaetz/2cd9c54fb1714e0d509f5f8215b3f5e6
# current version: https://gist.github.com/tony722/7c6d86be2e74fa10a1f344a4c2b093ea
#
# Notes: This is a script modified from the original to work with a FreePBX Distro PBX so that email notifications sent from
#        Asterisk voicemail contain a a speech to text transcription provided by Google Cloud Speech API
#
# License: There are no explicit license terms on the original script or on the blog post with modifications
#          I'm assumig GNU/GPL2+ unless notified otherwise by copyright holder(s)
#
# Version History:
# 2020-05-27  Add instructions from sr10952
#             Add export fix by levishores 
# 2019-02-27  Initial commit by tony722

# set PATH
PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"

# save the current directory
pushd .
 
# create a temporary directory and cd to it
TMPDIR=$(mktemp -d)
cd $TMPDIR
 
# dump the stream to a temporary file
cat >> stream.org
 
# get the boundary
BOUNDARY=$(grep "boundary=" stream.org | cut -d'"' -f 2)
 
# if mail has no boundaries, assume no attachment
if [ "$BOUNDARY" = "" ]
	
then
	# send the original stream
	mv stream.org stream.new
else
	# cut the original stream into parts
	# stream.part  - header before the boundary
	# stream.part1 - header after the bounday
	# stream.part2 - body of the message
	# stream.part3 - attachment in base64 (WAV file)
	# stream.part4 - footer of the message
	awk '/'$BOUNDARY'/{i++}{print > "stream.part"i}' stream.org
 
	# cut the attachment into parts
	# stream.part3.head - header of attachment
	# stream.part3.wav.base64 - wav file of attachment (encoded base64)
	sed '7,$d' stream.part3 > stream.part3.wav.head
	sed '1,6d' stream.part3 > stream.part3.wav.base64

	# convert the base64 file to a wav file
	dos2unix -o stream.part3.wav.base64
	base64 -di stream.part3.wav.base64 > stream.part3.wav

	# convert the wav file to FLAC
	sox -G stream.part3.wav --channels=1 --bits=16 --rate=8000 stream.part3.flac

	# convert to MP3
	sox stream.part3.wav stream.part3-pcm.wav
	lame -m m -b 24 stream.part3-pcm.wav stream.part3.mp3 
	base64 stream.part3.mp3 > stream.part3.mp3.base64

	# create mp3 mail part
	sed 's/x-[wW][aA][vV]/mpeg/g' stream.part3.wav.head | sed 's/.[wW][aA][vV]/.mp3/g' > stream.part3.new
	dos2unix -o stream.part3.new 
	unix2dos -o stream.part3.mp3.base64
	cat stream.part3.mp3.base64 >> stream.part3.new

	# save voicemail in tmp folder in case of trouble
	# TMPMP3=$(mktemp -u /tmp/msg_XXXXXXXX.mp3)
	# cp "stream.part3.mp3" "$TMPMP3"

	export CLOUDSDK_CONFIG=/home/asterisk/.config/gcloud
	RESULT=`gcloud ml speech recognize stream.part3.flac --language-code='en-US'`

	FILTERED=`echo "$RESULT" | jq -r '.results[].alternatives[].transcript'`
	 	   
	# generate first part of mail body, converting it to LF only
	mv stream.part stream.new
	cat stream.part1 >> stream.new
	sed '$d' < stream.part2 >> stream.new

	# beginning of transcription section
	echo "" >> stream.new
	echo "--- Google transcription result ---" >> stream.new

	# append result of transcription
	if [ -z "$FILTERED" 	]
	then
	  echo "(Google was unable to recognize any speech in audio data.)" >> stream.new
	else
	  echo "$FILTERED" >> stream.new
	fi

	# end of message body
	tail -1 stream.part2 >> stream.new

	# add converted attachment  
	cat stream.part3.new >> stream.new

	# append end of mail body, converting it to LF only
	echo "" >> stream.tmp
	echo "" >> stream.tmp
	cat stream.part4 >> stream.tmp
	dos2unix -o stream.tmp
	cat stream.tmp >> stream.new
 
fi
 
# send the mail thru sendmail
cat stream.new | sendmail -t
 
# go back to original directory
popd
 
# remove all temporary files and temporary directory
rm -Rf $TMPDIR