I am using HTK 3.4.1 in Ubuntu 12.04. I followed the guide in Vox Forge. However I got this error in re-aligning:
ERROR [+8522] LatFromPaths: Align have dur<=0
FATAL ERROR - Terminating program HVite
I searched with google and found some explaination like
'sp' is a tee model in the aligner, which is used to handle possible between-word pauses. It may have a zero duration. The tee model doesn't work under htk3.4.1 when doing alignment (Align have dur<=0), but 3.4 works. align.py inserts 'sp' between words before doing alignment, that may be why sometimes you'll see an error but sometimes not when using 3.4.1. Also, if the transcription words are very different from what's in the speech, the aligner will also report an error, meaning that it cannot find boundaries "confidently".
and related explaination for this error here (http://www.ee.uwa.edu.au/~roberto/research/speech/local/entropic/HAPIBook/node276.html) says:
"Lattice structure invalid
The lattice was incorrectly formed. Ensure that the lattice was created properly."
Does anyone have similar experience?