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Whisper Automatic Speech Recognition C Sample

Table of Contents​

  1. Download OpenVINO GenAI
  2. Build Samples
  3. Download and Convert the Model
  4. Prepare Audio File
  5. Sample Description
  6. Troubleshooting
  7. Support and Contribution

Download OpenVINO GenAI​

Download and extract OpenVINO GenAI Archive Visit the OpenVINO Download Page.

Build Samples​

Set up the environment and build the samples Linux and macOS:

source <INSTALL_DIR>/setupvars.sh
./<INSTALL_DIR>/samples/c/build_samples.sh

Windows Command Prompt:

<INSTALL_DIR>\setupvars.bat
<INSTALL_DIR>\samples\c\build_samples_msvc.bat

Windows PowerShell:

.<INSTALL_DIR>\setupvars.ps1
.<INSTALL_DIR>\samples\c\build_samples.ps1

Download and Convert the Model​

The --upgrade-strategy eager option is needed to ensure optimum-intel is upgraded to the latest version.

Install ../../export-requirements.txt if model conversion is required.

pip install --upgrade-strategy eager -r ../../export-requirements.txt
optimum-cli export openvino --trust-remote-code --model openai/whisper-tiny whisper-tiny

If a converted model in OpenVINO IR format is available in the OpenVINO optimized models collection on Hugging Face, you can download it directly via hf

For example:

pip install huggingface-hub
hf download OpenVINO/whisper-tiny-int8-ov --local-dir whisper-tiny-int8-ov

Prepare audio file​

Prepare audio file in wav format with sampling rate 16k Hz.

You can download example audio file: https://storage.openvinotoolkit.org/models_contrib/speech/2021.2/librispeech_s5/how_are_you_doing_today.wav

Sample Description​

This example showcases inference of speech recognition Whisper Models using the OpenVINO GenAI C API. The sample features ov_genai_whisper_pipeline and uses audio files in WAV format as input.

Run Command​

./whisper_speech_recognition_c <MODEL_DIR> "<WAV_FILE_PATH>" [DEVICE]

Parameters​

  • MODEL_DIR: Path to the converted Whisper model directory
  • WAV_FILE_PATH: Path to the WAV audio file (use quotes if path contains spaces)
  • DEVICE: Optional - device to run inference on (default: "CPU")

Example Usage​

./whisper_speech_recognition_c whisper-tiny how_are_you_doing_today.wav

Expected Output​

 How are you doing today?
timestamps: [0.00, 2.00] text:  How are you doing today?

The sample will:

  1. Load the WAV audio file and validate its format
  2. Automatically resample to 16kHz if needed
  3. Perform speech-to-text transcription
  4. Output the full transcription
  5. Display word-level timestamps for each text chunk

Troubleshooting​

Empty or Incorrect Output​

If you get empty or incorrect transcription results:

  • Ensure your audio file is in WAV format
  • Check that the audio contains clear speech

Model Loading Errors​

If the model fails to load:

  • Verify the model path exists and contains valid Whisper model files
  • Ensure the model was properly converted to OpenVINO IR format
  • Check that the specified device (CPU, GPU, etc.) is available on your system

Audio File Errors​

The sample provides detailed error messages for common audio file issues:

  • File not found
  • Permission denied
  • Invalid WAV format
  • Unsupported audio encoding (only PCM is supported)
  • Multi-channel audio (only mono is supported)

Support and Contribution​