forked from Mirrors/freeswitch
207 lines
7.5 KiB
Python
207 lines
7.5 KiB
Python
from freeswitch import *
|
|
from xml.dom import minidom
|
|
|
|
VOICE_ENGINE = "cepstral"
|
|
VOICE = "William"
|
|
|
|
"""
|
|
A few classes that make it easier to write speech applications
|
|
using Python. It is roughly modelled after the equivalent that
|
|
is written in JavaScript.
|
|
|
|
Status: should work, but not yet complete. some pending items
|
|
are mentioned in comments
|
|
"""
|
|
|
|
class Grammar:
|
|
def __init__(self, name, path, obj_path,
|
|
min_score=1, confirm_score=400, halt=False):
|
|
"""
|
|
@param name - name of grammar to reference it later
|
|
@param path - path to xml grammar file
|
|
@param obj_path - xml path to find interpretation from root
|
|
in result xml, eg, 'interpretation'
|
|
@param min_score - score threshold to accept result
|
|
@param confirm_score - if score below this threshold, ask user
|
|
if they are sure this is correct
|
|
@param halt - not sure what was used for in js, currently unused
|
|
"""
|
|
self.name=name
|
|
self.path=path
|
|
self.obj_path=obj_path
|
|
self.min_score=min_score
|
|
self.confirm_score=confirm_score
|
|
self.halt=halt
|
|
|
|
|
|
class SpeechDetect:
|
|
|
|
def __init__(self, session, module_name, ip_addr):
|
|
self.session=session
|
|
self.module_name=module_name
|
|
self.ip_addr=ip_addr
|
|
self.grammars = {}
|
|
|
|
def addGrammar(self, grammar):
|
|
self.grammars[grammar.name]=grammar
|
|
|
|
def setGrammar(self, name):
|
|
self.grammar = self.grammars[name]
|
|
|
|
def detectSpeech(self):
|
|
# TODO: we might not always want to call detect_speech
|
|
# with this cmd, see js version for other options
|
|
# also see detect_speech_function() in mod_dptools.c
|
|
cmd = "%s %s %s %s" % (self.module_name,
|
|
self.grammar.name,
|
|
self.grammar.path,
|
|
self.ip_addr)
|
|
console_log("debug", "calling detect_speech with: %s\n" % cmd)
|
|
self.session.execute("detect_speech", cmd)
|
|
console_log("debug", "finished calling detect_speech\n")
|
|
|
|
class SpeechObtainer:
|
|
|
|
def __init__(self, speech_detect, required_phrases, wait_time, max_tries):
|
|
"""
|
|
@param speech_detect - the speech detect object, which holds a
|
|
reference to underlying session and can
|
|
be re-used by many SpeechObtainers
|
|
@param required_phrases - the number of required phrases from the
|
|
grammar. for example if its prompting for
|
|
the toppings on a sandwhich and min toppings
|
|
is 3, use 3. normally will be 1.
|
|
@param wait_time - the time, in millisconds, to wait for
|
|
input during each loop iteration
|
|
@param max_tries - this number multiplied by wait time gives the
|
|
'total wait time' before we give up and return
|
|
partial or no result
|
|
"""
|
|
self.speech_detect=speech_detect
|
|
self.required_phrases=required_phrases
|
|
self.wait_time=wait_time
|
|
self.max_tries=max_tries
|
|
|
|
self.detected_phrases = []
|
|
self.failed = False
|
|
|
|
def setGrammar(self, grammar):
|
|
"""
|
|
@param grammar - instance of grammar class
|
|
"""
|
|
self.grammar=grammar
|
|
self.speech_detect.addGrammar(grammar)
|
|
self.speech_detect.setGrammar(self.grammar.name)
|
|
|
|
def detectSpeech(self):
|
|
self.speech_detect.detectSpeech()
|
|
|
|
def run(self):
|
|
"""
|
|
start speech detection with the current grammar,
|
|
and listen for results from asr engine. once a result
|
|
has been returned, return it to caller
|
|
"""
|
|
|
|
def dtmf_handler(input, itype, funcargs):
|
|
console_log("INFO","\n\nDTMF itype: %s\n" % itype)
|
|
if itype == 1: # TODO!! use names for comparison instead of number
|
|
return self.handle_event(input, funcargs)
|
|
elif itype== 0:
|
|
console_log("INFO","\n\nDTMF input: %s\n" % input)
|
|
else:
|
|
console_log("INFO","\n\nUnknown input type: %s\n" % itype)
|
|
return None
|
|
|
|
|
|
num_tries = 0
|
|
|
|
session = self.speech_detect.session
|
|
|
|
console_log("debug", "setting dtmf callback\n")
|
|
session.setDTMFCallback(dtmf_handler, "")
|
|
console_log("debug", "calling getDigits\n")
|
|
|
|
console_log("debug", "starting run() while loop\n")
|
|
while (session.ready() and
|
|
num_tries < self.max_tries and
|
|
len(self.detected_phrases) < self.required_phrases and
|
|
not self.failed):
|
|
console_log("debug", "top of run() while loop\n")
|
|
session.collectDigits(self.wait_time)
|
|
num_tries += 1
|
|
|
|
console_log("debug", "while loop finished\n")
|
|
return self.detected_phrases
|
|
|
|
def handle_event(self, event, funcargs):
|
|
"""
|
|
when the dtmf handler receives an event, it calls back
|
|
this method. event is a dictionary with subdictionaries ..
|
|
|
|
Example 1
|
|
=========
|
|
|
|
{'body': None, 'headers': {'Speech-Type': 'begin-speaking'}}
|
|
|
|
Example 2
|
|
=========
|
|
{'body': '<result xmlns='http://www.ietf.org/xml/ns/mrcpv2'
|
|
xmlns:ex='http://www.example.com/example' score='100'
|
|
grammar='session:request1@form-level.store'><interpretation>
|
|
<input mode='speech'>waffles</input></interpretation></result>',
|
|
'headers': {'Speech-Type': 'detected-speech'}}
|
|
|
|
This dictionary is constructed in run_dtmf_callback() in
|
|
freeswitch_python.cpp
|
|
|
|
"""
|
|
|
|
# what kind of event?
|
|
headers = event['headers']
|
|
speech_type = headers['Speech-Type']
|
|
if speech_type == "begin-speaking":
|
|
# not sure what to do with this, try returning "stop"
|
|
# so that it might stop playing a sound file once
|
|
# speech has been detected
|
|
return "stop"
|
|
elif speech_type == "detected-speech":
|
|
# extract the detected phrase. from result
|
|
# BUG: this assumes only ONE interpretation in the xml
|
|
# result. rest will get igored
|
|
# NOTE: have to wrap everything with str() (at least
|
|
# calls to console_log because otherwise it chokes on
|
|
# unicode strings.
|
|
# TODO: check the score
|
|
body = event['body']
|
|
if not body or len(body) == 0 or body == "(null)":
|
|
# freeswitch returned a completely empty result
|
|
self.failed = True
|
|
# do we want to return stop? what should we return?
|
|
return "stop"
|
|
|
|
dom = minidom.parseString(body)
|
|
phrase = dom.getElementsByTagName(self.grammar.obj_path)[0]
|
|
phrase_text = self.getText(phrase)
|
|
if phrase_text:
|
|
self.detected_phrases.append(str(phrase_text))
|
|
# do we want to return stop? what should we return?
|
|
return "stop"
|
|
else:
|
|
raise Exception("Unknown speech event: %s" % speech_type)
|
|
|
|
|
|
def getText(self, elt):
|
|
|
|
""" given an element, get its text. if there is more than
|
|
one text node child, just append all the text together.
|
|
"""
|
|
|
|
result = ""
|
|
children = elt.childNodes
|
|
for child in children:
|
|
if child.nodeType == child.TEXT_NODE:
|
|
result += str(child.nodeValue)
|
|
return result
|
|
|