mlx-examples/whisper/README.md

# Whisper

Speech recognition with Whisper in MLX. Whisper is a set of open source speech
recognition models from OpenAI, ranging from 39 million to 1.5 billion
parameters.[^1]

### Setup

First, install the dependencies:

```
pip install -r requirements.txt
```

Install [`ffmpeg`](https://ffmpeg.org/):

```
# on macOS using Homebrew (https://brew.sh/)
brew install ffmpeg
```

> [!TIP]
> Skip the conversion step by using pre-converted checkpoints from the Hugging
> Face Hub. There are a few available in the [MLX
> Community](https://huggingface.co/mlx-community) organization.

To convert a model, first download the Whisper PyTorch checkpoint and convert
the weights to the MLX format. For example, to convert the `tiny` model use:

```
python convert.py --torch-name-or-path tiny --mlx-path mlx_models/tiny
```

Note you can also convert a local PyTorch checkpoint which is in the original OpenAI format.

To generate a 4-bit quantized model, use `-q`. For a full list of options:

```
python convert.py --help
```

By default, the conversion script will make the directory `mlx_models`
and save the converted `weights.npz` and `config.json` there. 

Each time it is run, `convert.py` will overwrite any model in the provided
path. To save different models, make sure to set `--mlx-path` to a unique
directory for each converted model. For example:

```bash
model="tiny"
python convert.py --torch-name-or-path ${model} --mlx-path mlx_models/${model}_fp16
python convert.py --torch-name-or-path ${model} --dtype float32 --mlx-path mlx_models/${model}_fp32
python convert.py --torch-name-or-path ${model} -q --q_bits 4 --mlx-path mlx_models/${model}_quantized_4bits
```

### Run

Transcribe audio with:

```python
import whisper

text = whisper.transcribe(speech_file)["text"]
```

Choose the model by setting `path_or_hf_repo`. For example:

```python
result = whisper.transcribe(speech_file, path_or_hf_repo="models/large")
```

This will load the model contained in `models/large`. The `path_or_hf_repo`
can also point to an MLX-style Whisper model on the Hugging Face Hub. In this
case, the model will be automatically downloaded.

The `transcribe` function also supports word-level timestamps. You can generate
these with:

```python
output = whisper.transcribe(speech_file, word_timestamps=True)
print(output["segments"][0]["words"])
```

To see more transcription options use:

```
>>> help(whisper.transcribe)
```

[^1]: Refer to the [arXiv paper](https://arxiv.org/abs/2212.04356), [blog post](https://openai.com/research/whisper), and [code](https://github.com/openai/whisper) for more details.