Building

Kaldi

First install dependencies and build the speech recognition toolkit Kaldi, which Vosk is based on.

Get the code, which contains instructions and some scripts:

git clone -b lookahead --single-branch https://github.com/alphacep/kaldi

Note: If you run the command at a different time point, the code could be too old or too new to be compatible. You can checkout the revision the current Rust code is developed for: d39d716e3429742e35dbb7bc02401f7c7b40b83e.

Head over to the tools directory: cd kaldi/tools, and prepare some dependencies.

Running make may just work. Read the text file INSTALL for more info.

Linear Algebra Library

A library that provides BLAS and LAPACK is needed to perform matrix operations.

a) ATLAS

ATLAS (Automatically Tuned Linear Algebra Software) provides adequate support of BLAS and LAPACK for Kaldi. It may be available as precompiled packages. For example on Debian:

apt install libatlas-base-dev

b) OpenBLAS

Alternative implementation of BLAS and parts of LAPACK. Run script extras/install_openblas.sh to download and compile.

c) Intel-mkl

Yet another option. Script: extras/install_mkl.sh.

Kaldi compilation

Go to kaldi/src: cd ../src

Configure with mathlib set to the linear algebra library used:

./configure --mathlib=ATLAS --shared --use-cuda=no

Compile. Various object archive files should be available afterwards (such as nnet3/kaldi-nnet3.a):

make -j 4

vosk-sys

cargo needs to find Kaldi. Set the environment variable KALDI_ROOT to the path of the Kaldi repository.

C++ code of vosk is added as a submodule. Run git submodule init and git submodule update to get the code.

Now cargo build can be run.