CODEWITHSUNDEEP
pythoncompython-2.7pywin32sapi
Moh
Moh

Reputation: 2087

Python: win32com.client.getevents("SAPI.SpSharedRecoContext") returns None

I have downloaded a piece of code showing how to use Windows Speech API (SAPI 5.1) on Windows 7 using Python 2.7.3 interpreter and have PyWin32 Build 218 installed on my system. Everything works great with the code:

from win32com.client import constants
import win32com.client
import pythoncom

"""Sample code for using the Microsoft Speech SDK 5.1 via COM in Python.
    Requires that the SDK be installed; it's a free download from
            http://microsoft.com/speech
    and that MakePy has been used on it (in PythonWin,
    select Tools | COM MakePy Utility | Microsoft Speech Object Library 5.1).

    After running this, then saying "One", "Two", "Three" or "Four" should
    display "You said One" etc on the console. The recognition can be a bit
    shaky at first until you've trained it (via the Speech entry in the Windows
    Control Panel."""
class SpeechRecognition:
    """ Initialize the speech recognition with the passed in list of words """
    def __init__(self, wordsToAdd):
        # For text-to-speech
        self.speaker = win32com.client.Dispatch("SAPI.SpVoice")
        # For speech recognition - first create a listener
        self.listener = win32com.client.Dispatch("SAPI.SpSharedRecognizer")
        # Then a recognition context
        self.context = self.listener.CreateRecoContext()
        # which has an associated grammar
        self.grammar = self.context.CreateGrammar()
        # Do not allow free word recognition - only command and control
        # recognizing the words in the grammar only
        self.grammar.DictationSetState(0)
        # Create a new rule for the grammar, that is top level (so it begins
        # a recognition) and dynamic (ie we can change it at runtime)
#         self.wordsRule = self.grammar.Rules.Add("wordsRule",constants.SRATopLevel + constants.SRADynamic, 0)

        # Clear the rule (not necessary first time, but if we're changing it
        # dynamically then it's useful)
#         self.wordsRule.Clear()
        self.wordsRule = self.grammar.Rules.Add("wordsRule",1)
        self.wordsRule.Clear()
        # And go through the list of words, adding each to the rule
        [ self.wordsRule.InitialState.AddWordTransition(None, word) for word in wordsToAdd ]
        # Set the wordsRule to be active
        self.grammar.Rules.Commit()
        self.grammar.CmdSetRuleState("wordsRule", 1)
        # Commit the changes to the grammar
        self.grammar.Rules.Commit()
        # And add an event handler that's called back when recognition occurs
        self.eventHandler = ContextEvents(self.context)
        # Announce we've started using speech synthesis
        self.say("Started successfully")
    """Speak a word or phrase"""
    def say(self, phrase):
        self.speaker.Speak(phrase)


"""The callback class that handles the events raised by the speech object.
    See "Automation | SpSharedRecoContext (Events)" in the MS Speech SDK
    online help for documentation of the other events supported. """
class ContextEvents(win32com.client.getevents("SAPI.SpSharedRecoContext")):
    """Called when a word/phrase is successfully recognized  -
        ie it is found in a currently open grammar with a sufficiently high
        confidence"""
    def OnRecognition(self, StreamNumber, StreamPosition, RecognitionType, Result):
        newResult = win32com.client.Dispatch(Result)
        print "You said: ",newResult.PhraseInfo.GetText()

if __name__=='__main__':
    wordsToAdd = [ "One", "Two", "Three", "Four" ]
    speechReco = SpeechRecognition(wordsToAdd)
    while 1:
        pythoncom.PumpWaitingMessages()

But I get this exception: class ContextEvents(win32com.client.getevents("SAPI.SpSharedRecoContext")): TypeError: Error when calling the metaclass bases cannot create 'NoneType' instances

I did search all over the web, the only thing that I came up was this: TypeError: Error when calling the metaclass bases

It was no help so I searched more, and did some investigation on parts of code, so I found out that win32com.client.getevents("SAPI.SpSharedRecoContext") retuens None and consequently when it is used to be the base class, that exception is thrown.

So, what's the problem? How could I fix this problem? Otherwise could I use any other way to use SAPI 5.1 for speech recognition?

Note: I am aware of the SpeechPy project, but I have to use Windows API.

Thanks.

Upvotes: 2

Views: 2617

Answers (2)

Lazik
Lazik

Reputation: 2520

You forgot to run MakePy.
If you installed pyWin32, it also installed PythonWin.

Open PythonWin then select Tools | COM MakePy Utility | Microsoft Speech Object Library 5.4

Upvotes: 3

Eric Brown
Eric Brown

Reputation: 13932

I don't know anything about Python, but I did notice that you're not setting any event interests on your context, so SAPI will never call you back. You're also not enabling the context (via context.State), either.

At the very least, you need something like

self.context.EventInterests = 16
self.context.State = 1
self.eventHandler = ContextEvents(self.context)

to tell SAPI you're interested in recognition events, and to enable the context.

The entire list of SAPI events is available on MSDN

Upvotes: 0

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