sample_full_post_processor.py

#!/usr/bin/env python
'''
Sample script that shows how to postprocess full results from the kaldi-gstreamer-worker, encoded as JSON.

It adds a sentence confidence score to the 1-best hypothesis, deletes all other hypotheses and
adds a dot (.) to the end of the 1-best hypothesis. It assumes that the results contain at least two hypotheses,
The confidence scores are now normalized
'''

import sys
import json
import logging
from math import exp

def post_process_json(str):
    try:
        event = json.loads(str)
        if "result" in event:
            if len(event["result"]["hypotheses"]) > 1:
                likelihood1 = event["result"]["hypotheses"][0]["likelihood"]
                likelihood2 = event["result"]["hypotheses"][1]["likelihood"]
                confidence = likelihood1 - likelihood2
                confidence = 1 - exp(-confidence)
            else:
                confidence = 1.0e+10;
            event["result"]["hypotheses"][0]["confidence"] = confidence

            event["result"]["hypotheses"][0]["transcript"] += "."
            del event["result"]["hypotheses"][1:]
        return json.dumps(event)
    except:
        exc_type, exc_value, exc_traceback = sys.exc_info()
        logging.error("Failed to process JSON result: %s : %s " % (exc_type, exc_value))
        return str


if __name__ == "__main__":
    logging.basicConfig(level=logging.DEBUG, format="%(levelname)8s %(asctime)s %(message)s ")

    lines = []
    while True:
        l = sys.stdin.readline()
        if not l: break # EOF
        if l.strip() == "":
            if len(lines) > 0:
                result_json = post_process_json("".join(lines))
                print result_json
                print
                sys.stdout.flush()
                lines = []
        else:
            lines.append(l)

    if len(lines) > 0:
        result_json = post_process_json("".join(lines))
        print result_json
        lines = []