Asterisk voicemail mailcmd script for VM transcription

sendmail-bluemix

#!/bin/sh

# sendmail-bluemix
# current verison of this script: https://gist.github.com/lgaetz/2cd9c54fb1714e0d509f5f8215b3f5e6
#
#
# 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/
#
#
# 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 speech to text trasncription provided by IBM Bluemix
#
# 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)
#
# Usage: copy this file to /usr/sbin/ set ownership to asterisk:asterisk and make it executable.
#        In the [general] section of /etc/asterisk/voicemail.conf set mailcmd=/usr/sbin/sendmail-bluemix
#        This script also uses dos2unix, ensure it is executable by the asterisk user (chmod 777)
#
# Version History:
#              2017-09-17 Initial commit by lgaetz, working but unpolished
#              2017-09-18 Original attachment added to email
#              2017-09-18 fixed problem with email without attachments
#              2020-04-16 COVID-19 edition - updated to use API key using method from github user @jtsage

# Specify IBM Bluemix API credentials
# follow instructions here to get key and url https://cloud.ibm.com/docs/speech-to-text?topic=speech-to-text-gettingStarted
# key is long string separated by underscore(s). API_OPTS assumes US english, but there are many other language options available
# see full API reference at: https://cloud.ibm.com/apidocs/speech-to-text
API_KEY="xxxxxxxxx_xxxxxxxxxxxxxxx_xxxxxxxxxxxxxxxxxx"
API_URL="https://api.us-south.speech-to-text.watson.cloud.ibm.com/instances/yyyyyyyy-yyyy-yyyy-yyyy-yyyyyyyyyyyy"
API_OPTS="/v1/recognize?model=en-US_NarrowbandModel"

# 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
 
 	# Send WAV to Watson Speech to Text API. Must use "Narrowband" (aka 8k) model since WAV is 8k sample
	# Send WAV to Watson Speech to Text API. Must use "Narrowband" (aka 8k) model since WAV is 8k sample
	CURL_OPTS=""
	curl -s $CURL_OPTS -k -u "apikey:$API_KEY" -X POST \
		--limit-rate 40000 \
		--header "Content-Type: audio/wav" \
		--data-binary @stream.part3.wav \
		"$API_URL$API_OPTS" 1>audio.txt

	# Extract transcript results from JSON response
	TRANSCRIPT=`cat audio.txt | grep transcript | sed 's#^.*"transcript": "##g' | sed 's# "$##g'`
  
	# 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 "--- Automated transcription result ---" >> stream.new

	# append result of transcription
	echo "$TRANSCRIPT" >> stream.new

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

	# add orig attachment  
	cat stream.part3 >> 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