Detect if an hyp is a complete fsg sentence

[Mattia Ferrari]

Hello,
in my application I use pocketsphinx 0.7 with fsg (defined through a jsgf
file). While an utterance is being pronounced I wish to detect when the best
path hypotesis is a complete sentence of the rules defined in the jsgf, so
that I can end the utterance after a shorter period of silence after user's
voice when the sentence seems to be completed, and a longer period when the
sentence is half way.
I know that the string returned by ps_get_hyp() just before calling
ps_end_utt() can be different from the one returned after, but for my grammar
it happens almost never, so it is not be a problem for me.
A trivial solution could be to have my application continously check if the
string returned by ps_get_hyp() matches some of the complete phrases of the
grammar, but to do this I would have to parse the jsgf file myself, so it
would be much more convenient if I can get this information from somewhere
inside sphinx.

Thanks for any help.

[Nickolay V. Shmyrev]

Hello

I've just added API call to find this (ps_get_hyp_final) to pocketsphinx
trunk.

[Nickolay V. Shmyrev]

know that the string returned by ps_get_hyp() just before calling
ps_end_utt() can be different from the one returned after, but for my grammar
it happens almost never, so it is not be a problem for me.

And I recommend you to disable fwdflat and bestpath, they aren't really usable
for small vocabulary.

[Mattia Ferrari]

Thank you very much for the help.
I set fwdflat and bestpath to false and now it is much better.
I tried ps_get_hyp_final and it works when I use a grammar without nested
rules, for example:

public <first_rule> = go away;

but if I use a grammar with nested rules ps_get_hyp_final always says that the
hyp is not final, for example:

public <first_rule> = <second_rule>;
<second_rule> = go away;

These are the two fsgs produced:

Without nesting

0 2 go -0.000000
2 3 away -0.000000
3 1 <eps> -0.000000
1 0

With nesting

0 2 <eps> -0.000000
2 4 go -0.000000
3 1 <eps> -0.000000
4 5 away -0.000000
5 1 <eps> -0.000000
5 3 <eps> -0.000000
1 0

[Nickolay V. Shmyrev]

Hello

This issue should be fixed in trunk, please update.

[Mattia Ferrari]

Thank you very much! Now it works well for me. Very useful feature.