Picovoice Platform
C Quick Start

Platforms

• Linux (x86_64)
• macOS (x86_64, arm64)
• Windows (x86_64)
• BeagleBone
• NVIDIA Jetson Nano
• Raspberry Pi (Zero, 2, 3, 4)

Requirements

• C99-compatible compiler
• CMake (3.4+)
• 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.

Setup

1. Clone the repository:

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

Usage

1. Include the public header files (picovoice.h and pv_picovoice.h) .
2. Link the project to an appropriate precompiled library for the target platform and load it.
3. Download language models for Porcupine and Rhino .
4. Download a keyword file based on the desired language and the target platform.
5. Download a context file based on the desired language and the target platform.
6. Construct the Picovoice object:

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

const char *porcupine_model_path = "${PPN_FILE_PATH}";
const char *keyword_path = "${KEYWORD_FILE_PATH}";
const float porcupine_sensitivity = 0.5f;

void wake_word_callback(void) {
    // logic to execute upon detection of wake word
}

const char *rhino_model_path = "${RHN_FILE_PATH}";
const char *context_path = "${CONTEXT_FILE_PATH}";
const float rhino_sensitivity = 0.75f;
const float endpoint_duration_sec = 1.0f;

void inference_callback(pv_inference_t *inference) {
    if (inference->is_understood) {
        if (inference->num_slots > 0) {
            for (int32_t i = 0; i < inference->num_slots; i++) {
               # take action based on intent and slot values
            }
        }
    } else {
         # unsupported command
    }
    
    pv_inference_delete(inference);
}

pv_picovoice_t *picovoice = NULL;

const pv_status_t status = pv_picovoice_init(
            ACCESS_KEY,
            porcupine_model_path,
            keyword_path,
            porcupine_sensitivity,
            wake_word_callback,
            rhino_model_path,
            context_path,
            rhino_sensitivity,
            endpoint_duration_sec,
            true,
            inference_callback,
            &picovoice);

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

7. Pass in frames of audio to the pv_picovoice_process_func function:

extern const int16_t *get_next_audio_frame(void);

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

8. Release resources explicitly when done with Picovoice:

pv_picovoice_delete(picovoice);

Custom Wake Words & Contexts

Create custom wake word and context files using the Picovoice Console . Download the custom models (.ppn and .rhn) and create an instance of Picovoice using the custom models.

Non-English Languages

Use the corresponding model file (.pv) to process non-English wake words and contexts. The model files for all supported languages are available on the Porcupine GitHub repository and the Rhino GitHub repository .

Demo

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

Setup

1. Clone the repository:

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

2. Build the microphone demo:

cd picovoice
cmake -S demo/c/. -B demo/c/build && cmake --build demo/c/build --target picovoice_demo_mic

Usage

To see the usage options for the demo:

./demo/c/build/picovoice_demo_mic

Ensure you have a working microphone connected to your system and run the following command to infer intent from spoken commands:

./demo/c/build/picovoice_demo_mic \
-a ${ACCESS_KEY}
-l sdk/c/lib/${PLATFORM}/${ARCH}/libpicovoice.so \
-p resources/porcupine/lib/common/porcupine_params.pv \
-k resources/porcupine/resources/keyword_files/${PLATFORM}/picovoice_${PLATFORM}.ppn \
-r resources/rhino/lib/common/rhino_params.pv \
-c resources/rhino/resources/contexts/${PLATFORM}/smart_lighting_${PLATFORM}.rhn \
-i {AUDIO_DEVICE_INDEX}

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

Resources