VibeASR.cpp is the official inference runtime for VibeVoice-ASR-BitNet — enabling real-time multilingual speech recognition on CPU through heterogeneous quantization (I8_S for VAE + I2_S for LM).

To enable efficient edge CPU deployment, we replace the original Qwen2.5-7B language model with Qwen2.5-1.5B, achieving only modest accuracy degradation (1–4% absolute WER increase) while reducing the total model size from 4.62 GB to 1.58 GB. Combined with custom SIMD kernels and operator fusion in the ggml framework, VibeVoice-ASR-BitNet achieves 1.6–2.7× faster inference than Whisper.cpp at comparable model sizes, with real-time capability (RTF < 1) on low-resource CPUs.

📄 Tech Report  |  🤗 Models  |  ✨ Demo  |  🏠 GeneralAI

RTF (Real-Time Factor) on audio input, excluding one-time model loading. Bold = RTF < 1 (real-time). All numbers are measured on a ~20 s clip in steady state (one warm-up pass excluded).

Note: The accuracy benchmarks above are evaluated on standard-accent speech corpora. Performance on accented or dialectal speech not represented in the training data may degrade more significantly, as is common with ASR models trained on specific data distributions.

• Python ≥ 3.9, CMake ≥ 3.14, GCC/Clang with C++11 support
• ~2 GB disk space (code + quantized models)

Windows users: MSVC is not supported — the build requires GCC or Clang (MinGW-w64 recommended). See Notes for Windows below.

git clone --recursive https://github.com/microsoft/VibeASR.cpp.git
cd VibeASR.cpp
pip install -r requirements.txt
python setup_env.py

git clone --recursive https://github.com/microsoft/VibeASR.cpp.git
cd VibeASR.cpp

# Build
cmake -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build -j$(nproc)

# Download pre-quantized models
pip install huggingface_hub
huggingface-cli download microsoft/VibeVoice-ASR-BitNet --local-dir models/vibeasr

./build/bin/asr_infer \
    --vae-model models/vibeasr/vibeasr-vae-encoder-i8_s.gguf \
    --lm-model models/vibeasr/vibeasr-lm-i2_s-embed-q6_k.gguf \
    --audio input.wav -t 4

pip install gradio soundfile numpy

python demo/gradio_asr_demo.py --port 7860 \
    --vae-model models/vibeasr/vibeasr-vae-encoder-i8_s.gguf \
    --lm-model models/vibeasr/vibeasr-lm-i2_s-embed-q6_k.gguf

Windows builds require GCC or Clang — MSVC is rejected by src/CMakeLists.txt. MinGW-w64 (e.g. WinLibs) is recommended. Use the MinGW Makefiles generator, and keep the MinGW bin dir on your PATH at runtime so the executables find their DLLs:

cmake -B build -G "MinGW Makefiles" -DCMAKE_BUILD_TYPE=Release \
    -DCMAKE_C_COMPILER=gcc -DCMAKE_CXX_COMPILER=g++ -DCMAKE_MAKE_PROGRAM=mingw32-make
cmake --build build --target asr_infer -j

• Build with the command above rather than setup_env.py (its clang probe assumes a POSIX shell).
• Gradio: run python demo/gradio_asr_demo.py --port 7860 (model paths come from the script's MODEL_CONFIGS, not --vae-model/--lm-model; pass --bin build/bin/asr_infer.exe if needed).

For most users, downloading pre-quantized models from HuggingFace is recommended. To convert from SafeTensors yourself:

# LM (BitNet) — handles weight preprocessing and config flattening automatically
python utils/convert_lm_to_gguf.py <safetensors-dir>

# VAE Tokenizer
python utils/convert_vae_to_gguf.py <safetensors-dir>

# VAE Tokenizer: F32 → I8_S
./build/bin/llama-quantize \
    <safetensors-dir>/vibeasr-vae-encoder-f32.gguf \
    <safetensors-dir>/vibeasr-vae-encoder-i8_s.gguf \
    I8_S 1 1

# LM: F32 → I2_S (with Q6_K embeddings)
./build/bin/llama-quantize --token-embedding-type Q6_K \
    <safetensors-dir>/vibeasr-lm-f32.gguf \
    <safetensors-dir>/vibeasr-lm-i2_s-embed-q6_k.gguf \
    I2_S 1 1

@article{xu2025vibeasrbitnet,
    title={VibeVoice-ASR-BitNet Technical Report},
    author={Xu, Songchen and Song, Ting and Huang, Shaohan and Peng, Zhiliang and Xia, Yan and Tu, Yujie and Huang, Xin and Yu, Jianwei and Dong, Li and Wei, Furu},
    journal={arXiv preprint arXiv:2607.21075},
    year={2025}
}

This project is licensed under the MIT License.