Koala Noise Suppression Engine
C Quick Start

Platforms

• Linux (x86_64)
• macOS (x86_64, arm64)
• Windows (x86_64)
• NVIDIA Jetson Nano
• Raspberry Pi (3, 4)

Requirements

• C99-compatible compiler
• CMake (3.13+)
• For Windows Only: MinGW is required to build the demo

Picovoice Account & AccessKey

Signup or Login to Picovoice Console to get your AccessKey. Make sure to keep your AccessKey secret.

Quick Start

Setup

1. Clone the repository:

git clone --recurse-submodules https://github.com/Picovoice/koala.git

Usage

1. Include the public header files (picovoice.h and pv_koala.h) .
2. Link the project to an appropriate precompiled library for the target platform and load it.
3. Construct the Koala object:

static const char* ACCESS_KEY = "${ACCESS_KEY}";
static const char* MODEL_PATH = "${MODEL_PATH}";

pv_koala_t *koala;

const pv_status_t status = pv_koala_init(
    access_key, 
    model_path, 
    &koala);

if (status != PV_STATUS_SUCCESS) {
    // error handling logic
}

4. Pass in audio to the pv_koala_process function:

extern const int16_t *get_next_audio_frame(void);

const int32_t frame_length = pv_koala_frame_length();
int16_t *enhanced_pcm = (int16_t *) malloc(frame_length * sizeof(int16_t));

while (true) {
    const int16_t *pcm = get_next_audio_frame();
    const pv_status_t status = pv_koala_process(handle, pcm, enhanced_pcm);
    if (status != PV_STATUS_SUCCESS) {
        // error handling logic
    }
}

free(enhanced_pcm);

5. Release resources explicitly when done with Koala:

pv_koala_delete(koala);

Demo

For the Koala SDK, we offer demo applications that demonstrate how to use the Noise Suppression engine on real-time audio streams (i.e. microphone input) and audio files.

Setup

1. Clone the Koala repository from GitHub using HTTPS:

git clone --recurse-submodules https://github.com/Picovoice/koala.git

2. Build the microphone demo:

cd koala
cmake -S demo/c/. -B demo/c/build
cmake --build demo/c/build --target koala_demo_mic

Usage

To see the usage options for the demo:

./demo/c/build/koala_demo_mic

Ensure you have a working microphone connected to your system and run the following command to record microphone input, remove noise, and write the cleaned audio to a file:

./demo/c/build/koala_demo_mic \
-l lib/${PLATFORM}/${ARCH}/libpv_koala.${LIB_EXTENSION} \
-m lib/common/koala_params.pv \
-a ${ACCESS_KEY} \
-d ${AUDIO_DEVICE_INDEX} \
-o ${WAV_OUTPUT_PATH}

For more information on our Koala demos for C, head over to our GitHub repository .

Resources