Using Google's Speech Recognition Web Service with Python

The reverse engineering has already been done in this tutorial. I received the hint from a friendly fellow student. Here is a Python script doing the same job. Note that the web service (see the demo page) accepts audio in the FLAC format. Use the flac program in order to convert wave to flac.

#!/usr/bin/env python2
# -*- coding: utf-8 -*-

import httplib
import json
import sys

def speech_to_text(audio):
    url = "www.google.com"
    path = "/speech-api/v1/recognize?xjerr=1&client=chromium&lang=en"
    headers = { "Content-type": "audio/x-flac; rate=16000" };
    params = {"xjerr": "1", "client": "chromium"}
    conn = httplib.HTTPSConnection(url)
    conn.request("POST", path, audio, headers)
    response = conn.getresponse()
    data = response.read()
    jsdata = json.loads(data)
    return jsdata["hypotheses"][0]["utterance"]

if __name__ == "__main__":
    if len(sys.argv) != 2 or "--help" in sys.argv:
        print "Usage: stt.py <flac-audio-file>"
        sys.exit(-1)
    else:
        with open(sys.argv[1], "r") as f:
            speech = f.read()
        text = speech_to_text(speech)
        print text

Download the file: Python script for accessing Google’s web-based speech recognition service