Pocketsphinx.js Multiple Keyword example

This is an example of how to use mutiple keywords with Pocketsphinx.js.

Demo

http://lab.miguelmota.com/pocketsphinxjs-multiple-keywords

Running example

$ git clone https://github.com/miguelmota/pocketsphinxjs-multiple-keywords.git
$ cd pocketsphinxjs-multiple-keywords
$ python -m SimpleHTTPServer 8000

Navigate to http://localhost:8000/ in your browser.

Generating pocketsphinx.js with dictionary

Download Portable Emscripten:

$ cd ~/Downloads/emsdk_portable

# Fetch the latest registry of available tools.
$ ./emsdk update

# Download and install the latest SDK tools.
$ ./emsdk install latest

# Make the "latest" SDK "active"
$ ./emsdk activate latest

Download Emscripten:

$ cd ~/Downloads
$ git clone https://github.com/kripken/emscripten.git

Download Pocketsphinx.js:

$ git clone https://github.com/syl22-00/pocketsphinx.js.git
$ git submodule init
$ git submodule update

Create a dictionary file:

$ cd ~/Downloads/pocketsphinx.js/
$ mkdir dicts
$ vim dicts/keyphrase.dict

keyphrase.dict:

CAT K AE T
DOG D AO G
FISH F IH SH

Note: Check out the CMU Sphinx Pronouncing Dictionary for getting English dictionary phonemes. For convenience I have wrapped it in a CLI tool, cmusphinxdict.

Now compile pocketsphinx with dictionary.

$ cd ~/Downloads/pocketsphinx.js/
$ cmake -DEMSCRIPTEN=1 -DCMAKE_TOOLCHAIN_FILE=/Users/username/Downloads/emscripten/cmake/Modules/Platform/Emscripten.cmake -DDICT_BASE=./dicts -DDICT_FILES=keyphrase.dict .

Copying /Users/username/Sandbox/pocketsphinx.js/am/rm1_200 to binary dir
Copying ./dicts/keyphrase.dict to binary dir
-- Configuring done
-- Generating done
-- Build files have been written to: /Users/username/Sandbox/pocketsphinx.js

Then run make to generate pocketsphinx.js with embeded dictionary:

$ make

[  1%] Building CXX object CMakeFiles/pocketsphinx.dir/src/psRecognizer.cpp.o
...
[100%] Built target pocketsphinx.js

Note: You can also compile pocketsphinx without a dictionary to add the words dynamically.

$ cmake -DEMSCRIPTEN=1 -DCMAKE_TOOLCHAIN_FILE=/Users/username/Downloads/emscripten/cmake/Modules/Platform/Emscripten.cmake  .

Generating keyword list for pocketsphinx.js

cd ~/Downloads/pocketsphinx.js/
vim keyphrase.list

keyphrase.list:

CAT /1e-15/
DOG /1e-15/
FISH /1e-12/

Notes on keyphrase thresholds:

• One phrase per line with threshold for each phrase.
• Threshold must be selected to avoid false alarms.
• The threshold depends on the word, for optimal detection you need to use word-specific thresholds.
• Default threshold is 1.
• Threshold can be in scientific notation or decimal notation: /1e-1/ or /0.1/
• If you have too many false alarms try reducing keyword threshold.
• Try keyword threshold values such as 1e-60, 1e-40, 1e-20, 1e-10, etc.
• Bigger threshold drops uncertain occurrences of keyword, decreasing amount of false alarms. I.E. 1e-10 > 1e-30.

Compile keyhprases to JavaScript file for pocketsphinx.js:

$ cd ~/Downloads/pocketsphinx.js/
$ python ../emscripten/tools/file_packager.py ./pocketsphinx.js --embed keyphrase.list --js-output=keyphrase-list.js

Testing keyphrase list in command line

Pocketphinx comes with pocketsphinx_continuous which allows you to do live testing.

$ cd ~/Downloads/pocketsphinx.js/
$ pocketsphinx_continuous -inmic yes -kws keyphrase.list -dict dicts/keyphrase.dic

You can also record an audio file using sox and use that instead of the live microphone:

$ sox -d -c 1 -r 16000 -e signed -b 16 dog.wav

$ pocketsphinx_continuous -infile dog.wav -kws keyphrase.list -dict dicts/keyphrase.dict

License

PocketSphinx is released under the BSD License.

PocketSphinx.js is released under the MIT License.

This example is released under the MIT License.