Voice memo transcriber engine. This is a very simple, highly inflexible script that probably won't be useful to many other people, but hey, you never know!

transcriber.rb

=begin README

Here's what this script does:

1. checks a Gmail inbox
2. finds attachments (which it expects to be WAV files)
3. pipes them through Google's voice transcription service
4. emails you the results

I use it with the Instacorder iPhone app for a super-fast, push-to-talk
voice memo transcription service, with no steps/confirmations along the way.

A few important things to know:

1. Google's transcription API maxes out at around 60 seconds. Longer recordings
~fail silently~.

2. I have this script running as a cron job on a desktop computer. You could
just as easily run it manually, put it on a server, etc.

3. I use a dedicated email account for voice memos, so the script naively plows
through EVERYTHING. It wouldn't be hard to modify it to discriminate between
emails/attachments -- maybe most easily using some key in the subject line?

3a. But, absent such modification: don't run this script on your everyday Gmail
account!!

4. To get your GOOGLE_KEY for the Speech API, you'll need to follow the
directions here, including the part where you sign up for the chromium-dev
group: http://www.chromium.org/developers/how-tos/api-keys

That's it!

=end

require "rubygems"
require "mail"
require "gmail"
require "json"

# also requires: curl on the command line

# CONST #

GMAIL_POWERED_ADDRESS = "[email protected]" # also works with google apps for your domain
PASSWORD = "password"
GOOGLE_KEY = "key_with_speech_api_enabled" # see: http://www.chromium.org/developers/how-tos/api-keys

TRANSCRIBED_EMAIL_TO = "[email protected]"
TRANSCRIBED_EMAIL_SUBJECT = "Transcribed voice memo"

THIS_DIR = __dir__
AUDIO_DIR = "#{THIS_DIR}/audio" # you must create this directory
LOGFILE = "log.txt" # you must create this file
SPEW_LOG_TO_CONSOLE = false # false = save to logfile instead

# GLOBAL #

$gmail = Gmail.connect!(GMAIL_POWERED_ADDRESS, PASSWORD)

# METHODS #

def transcribe_audio(full_path_to_audio_file)

  log "transcribing #{full_path_to_audio_file}..."

  cmd = "curl -X POST --data-binary @'#{full_path_to_audio_file}' \
                      --header 'Content-Type: audio/l16; rate=16000;' \
                      'https://www.google.com/speech-api/v2/recognize?output=json&lang=en-us&key=#{GOOGLE_KEY}'"
  raw_response = `#{cmd}`

  best_transcript = raw_response.scan(/\"transcript\"\:\"(.+?)\"/)[0][0]
  # need to use [0][0] b/c of the way the capture group (.+?) returns its results

  log "transcribed as: #{best_transcript}..."
  return best_transcript
end

def log(msg)
  if SPEW_LOG_TO_CONSOLE then
    puts msg
  else
    open(File.join(THIS_DIR,"log.txt"), 'a') do |log_file|
      log_file.puts msg
    end
  end
end

def log_end
  log("---\n\n")

  # if logfile is larger than 10 megs...
  if ((File.size(File.join(THIS_DIR,"log.txt"))/1024000.0) > 10) then
    $gmail.deliver do
      to TRANSCRIBED_EMAIL_TO
      from GMAIL_POWERED_ADDRESS
      subject "ALERT: your transcriber.rb logfile is getting large"
      body "that's all :)"
    end
  end
end

#####################
#                   #
#  BEGIN ZE SCRIPT  #
#                   #
#####################

if $gmail.inbox.count(:unread) <= 0 then
  exit
end

log "found unread message(s) at #{Time.now}"

$gmail.inbox.find(:unread).each do |email|
  email.message.attachments.each do |attachment|
    full_path = File.join(AUDIO_DIR, attachment.filename)
    File.write(full_path, attachment.body.decoded)

    transcription_email = $gmail.compose do
      to TRANSCRIBED_EMAIL_TO
      from GMAIL_POWERED_ADDRESS
      subject TRANSCRIBED_EMAIL_SUBJECT
      body transcribe_audio(full_path)
    end

    begin
      transcription_email.deliver!
      email.read!
      log "transcription sent!"
    rescue
      log "well, something went wrong, so I didn't mark the email as read..."
    end
  end
end

log_end

$gmail.logout