C Keyword Spotting

No C++, no dependency hell. Suitable for embedded devices.

Demo

Default models pretrained on 0-9 words: zero one two three four five six seven eight nine.

~$ arecord -f S16_LE -c1 -r16000 -d1 test.wav
~$ aplay test.wav
~$ dataset/dataset/google_speech_commands/src/features/build.sh
~$ src/brain/build.sh
~$ alias fe=dataset/dataset/google_speech_commands/bin/fe
~$ fe test.wav | bin/guess models/mlp.model
~$ fe test.wav | bin/guess models/cnn.model
~$ fe test.wav | bin/guess models/rnn.model

Training

See google speech commands dataset for available words.

~$ apt install gcc lrzip wget
~$ wget https://github.com/42io/dataset/releases/download/v1.0/0-9up.lrz -O /tmp/0-9up.lrz
~$ lrunzip /tmp/0-9up.lrz -o /tmp/0-9up.data # md5 87fc2460c7b6cd3dcca6807e9de78833
~$ dataset/train.sh /tmp/0-9up.data 49 13 12 # inputs height, inputs width, outputs

It takes some time, be patient. Finally you'll see confusion matrix.

MLP confusion matrix...
zero  | 0.91 0.00 0.03 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.05 0.00 | 603
one   | 0.00 0.92 0.00 0.01 0.00 0.01 0.00 0.00 0.00 0.02 0.05 0.00 | 575
two   | 0.01 0.00 0.89 0.01 0.01 0.00 0.00 0.01 0.00 0.00 0.05 0.01 | 564
three | 0.00 0.00 0.01 0.92 0.00 0.01 0.00 0.01 0.02 0.00 0.03 0.01 | 548
four  | 0.00 0.01 0.01 0.00 0.89 0.00 0.00 0.00 0.00 0.00 0.07 0.00 | 605
five  | 0.00 0.01 0.00 0.01 0.00 0.84 0.00 0.01 0.01 0.02 0.08 0.00 | 607
six   | 0.00 0.00 0.00 0.00 0.00 0.00 0.97 0.00 0.00 0.00 0.01 0.01 | 462
seven | 0.01 0.00 0.01 0.01 0.00 0.00 0.01 0.93 0.00 0.00 0.03 0.00 | 574
eight | 0.00 0.00 0.01 0.03 0.00 0.00 0.01 0.00 0.91 0.00 0.03 0.01 | 547
nine  | 0.00 0.03 0.00 0.01 0.00 0.01 0.00 0.00 0.00 0.86 0.08 0.01 | 596
#unk# | 0.01 0.03 0.02 0.04 0.03 0.03 0.01 0.02 0.02 0.03 0.76 0.01 | 730
#pub# | 0.00 0.00 0.00 0.00 0.01 0.00 0.01 0.01 0.00 0.00 0.01 0.95 | 730
MLP guessed wrong 773...

CNN confusion matrix...
zero  | 0.97 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.03 0.00 | 603
one   | 0.00 0.93 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.06 0.00 | 575
two   | 0.01 0.00 0.95 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.02 0.00 | 564
three | 0.00 0.00 0.01 0.94 0.00 0.00 0.00 0.00 0.01 0.00 0.03 0.00 | 548
four  | 0.00 0.00 0.00 0.00 0.94 0.00 0.00 0.00 0.00 0.00 0.05 0.00 | 605
five  | 0.00 0.00 0.00 0.00 0.00 0.95 0.00 0.00 0.00 0.00 0.04 0.00 | 607
six   | 0.00 0.00 0.00 0.00 0.00 0.00 0.99 0.00 0.00 0.00 0.00 0.00 | 462
seven | 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.98 0.00 0.00 0.01 0.00 | 574
eight | 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.97 0.00 0.01 0.00 | 547
nine  | 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.94 0.05 0.00 | 596
#unk# | 0.00 0.01 0.00 0.01 0.01 0.00 0.00 0.00 0.00 0.00 0.95 0.01 | 730
#pub# | 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.99 | 730
CNN guessed wrong 291...

RNN confusion matrix...
zero  | 0.98 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.01 0.00 | 603
one   | 0.00 0.95 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.01 0.03 0.00 | 575
two   | 0.01 0.00 0.96 0.01 0.01 0.00 0.00 0.00 0.00 0.00 0.01 0.00 | 564
three | 0.00 0.00 0.00 0.94 0.00 0.00 0.00 0.00 0.02 0.00 0.02 0.00 | 548
four  | 0.00 0.00 0.00 0.00 0.97 0.00 0.00 0.00 0.00 0.00 0.02 0.00 | 605
five  | 0.00 0.00 0.00 0.00 0.01 0.98 0.00 0.00 0.00 0.00 0.00 0.00 | 607
six   | 0.00 0.00 0.00 0.00 0.00 0.00 0.98 0.00 0.00 0.00 0.01 0.00 | 462
seven | 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.98 0.00 0.00 0.01 0.00 | 574
eight | 0.00 0.00 0.00 0.01 0.00 0.01 0.00 0.00 0.97 0.00 0.01 0.00 | 547
nine  | 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.97 0.01 0.01 | 596
#unk# | 0.01 0.02 0.00 0.01 0.02 0.01 0.00 0.01 0.01 0.01 0.92 0.01 | 730
#pub# | 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.98 | 730
RNN guessed wrong 254...

Heap Memory Usage

Some magic numbers to know before stepping into embedded world.

~$ valgrind dataset/dataset/google_speech_commands/bin/fe test.wav # 606,416 bytes allocated
~$ fe test.wav | valgrind bin/guess models/mlp.model               # 622,768 bytes allocated
~$ fe test.wav | valgrind bin/guess models/cnn.model               # 2,445,100 bytes allocated
~$ fe test.wav | valgrind bin/guess models/rnn.model               # 403,772 bytes allocated

See ESP32 example.