[asterisk-dev] Speech Recognition

[Joshua Colp]

Stephan A. Edelman wrote:
> Hello,
> However, I have noticed several problems with the Speech API:
> 
> (1)     When loading another grammar, it still appears to be processing 
> voice frames from a previous recognition cycle. This is noticeable as 
> SpeechBackground() is silent immediately when called without playing the 
> sound file and even after SpeechStart() is called again. I have been 
> able to correct this problem by introducing *ast_clear_flag(speech, 
> AST_SPEECH_QUIET);* in the ast_speech_start() function of 
> res/res_speech.c, as follows:
> 

I agree with this too, fixed in 1.4 and trunk. A new 1.2 patch should be 
available from Lumenvox next week as well.

> 
> (2)     SpeechCreate() does not seem to report the correct status 
> (${SPEECH(status)}) when using the Lumenvox engine and there are no more 
> available licenses. This causes a subsequent call to 
> SpeechActivateGrammar() to drop the call. In fact, it doesn’t make sense 
> to me at all to have any of the Speech…() functions return -1 and cause 
> the call to be hung up. This doesn’t allow for any DTMF fallback schemes.
> 
> Can we have the Speech…() functions in apps/app_speech_utils.c set the 
> ${SPEECH(status)} variable appropriately instead? Any comments?
> 

I just took care of this in 1.4 and trunk. Give it a whirl.

> 
> (3)     SpeechBackground(Sound File|timeout) should treat a zero timeout 
> as meaning “timeout immediately after playing the sound file”. This 
> allows you to call SpeechBackground() back-to-back without any delay. 
> Presently, a zero timeout means that it waits indefinitely for the 
> user’s voice response. If no timeout is specified as a parameter then it 
> should behave with an indefinite timeout.
> 

Ideally I would like to move this application to use the file API for 
all this stuff instead of having to recreate some of the logic.

Final note:

If there's any other comments you have please do reply, I want the 
speech API to evolve to the needs of both the developers and the users.

-- 
Joshua Colp
Software Developer
Digium, Inc.