Whisper Auto Caption

This repo shows how to translate and automatically caption videos using Whisper and MoviePy.

Launch this in Paperspace Gradient by clicking the link below.

Launch Notebook

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The subtitle_video function

The subtitle_video function can be accessed through the whisper-caption.ipynb Notebook. This function uses Whisper and MoviePy to take in a video, extract its audio, convert its speech into text captions, and then add those captions at the correct timeslots back to the original video.

subtitle_video takes in the following parameters:

    download:       bool, this tells your function if you are downloading a youtube video
    url: str,       str, the URL of youtube video to download if download is True
    aud_opts:       dict, audio file youtube-dl options
    vid_opts:       dict, video file youtube-dl options
    model_type:     str, which pretrained model to download. Options are:
                    ['tiny', 'small', 'base', 'medium','large','tiny.en', 'small.en', 'base.en',  'medium.en']
                    More details about model_types can be found in table in original repo here:
                    https://github.com/openai/whisper#Available-models-and-languages
     name:          str, name of directory to store files in in experiments folder
     audio_file:    str, path to extracted audio file for Whisper
     input_file:    str, path to video file for MoviePy to caption
     output:        str, destination of final output video file
     uploaded_vid:  str, path to uploaded video file if download is False

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The Whisper AutoCaption Flask application

To deploy Whisper AutoCaption in the Flask web application, go to Gradient Deployments, and create a new deployment. Then fill in the values, and create the deployment. From there, all you need to do is click the API endpoint URL in the Deployment's details page.

From there, you can directly input any video from your local computer or Youtube URL.

image: paperspace/whisper-autocaption:v1.01
port: 5000
resources:
replicas: 1
instanceType: RTX4000

The full spec is as follows:

enabled: true
image: paperspace/whisper-autocaption:v1.01
port: 5000
resources:
  replicas: 1
  instanceType: RTX4000
  autoscaling:
    enabled: true
    maxReplicas: 5
    metrics:
      - metric: requestDuration
        summary: average
        value: 0.15
      - metric: cpu
        summary: average
        value: 30
      - metric: memory
        summary: average
        value: 45

---

Future plans:

• API version

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[Blog] [Paper] [Model card]

Whisper is a general-purpose speech recognition model. It is trained on a large dataset of diverse audio and is also a multi-task model that can perform multilingual speech recognition as well as speech translation and language identification.

Approach

A Transformer sequence-to-sequence model is trained on various speech processing tasks, including multilingual speech recognition, speech translation, spoken language identification, and voice activity detection. All of these tasks are jointly represented as a sequence of tokens to be predicted by the decoder, allowing for a single model to replace many different stages of a traditional speech processing pipeline. The multitask training format uses a set of special tokens that serve as task specifiers or classification targets.

Setup

We used Python 3.9.9 and PyTorch 1.10.1 to train and test our models, but the codebase is expected to be compatible with Python 3.7 or later and recent PyTorch versions. The codebase also depends on a few Python packages, most notably HuggingFace Transformers for their fast tokenizer implementation and ffmpeg-python for reading audio files. The following command will pull and install the latest commit from this repository, along with its Python dependencies

pip install git+https://github.com/openai/whisper.git

It also requires the command-line tool ffmpeg to be installed on your system, which is available from most package managers:

# on Ubuntu or Debian
sudo apt update && sudo apt install ffmpeg

# on Arch Linux
sudo pacman -S ffmpeg

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

# on Windows using Chocolatey (https://chocolatey.org/)
choco install ffmpeg

# on Windows using Scoop (https://scoop.sh/)
scoop install ffmpeg

You may need rust installed as well, in case tokenizers does not provide a pre-built wheel for your platform. If you see installation errors during the pip install command above, please follow the Getting started page to install Rust development environment. Additionally, you may need to configure the PATH environment variable, e.g. export PATH="$HOME/.cargo/bin:$PATH". If the installation fails with No module named 'setuptools_rust', you need to install setuptools_rust, e.g. by running:

pip install setuptools-rust

Available models and languages

There are five model sizes, four with English-only versions, offering speed and accuracy tradeoffs. Below are the names of the available models and their approximate memory requirements and relative speed.

Size	Parameters	English-only model	Multilingual model	Required VRAM	Relative speed
tiny	39 M	tiny.en	tiny	~1 GB	~32x
base	74 M	base.en	base	~1 GB	~16x
small	244 M	small.en	small	~2 GB	~6x
medium	769 M	medium.en	medium	~5 GB	~2x
large	1550 M	N/A	large	~10 GB	1x

For English-only applications, the .en models tend to perform better, especially for the tiny.en and base.en models. We observed that the difference becomes less significant for the small.en and medium.en models.

Whisper's performance varies widely depending on the language. The figure below shows a WER breakdown by languages of Fleurs dataset, using the large model. More WER and BLEU scores corresponding to the other models and datasets can be found in Appendix D in the paper.

Command-line usage

The following command will transcribe speech in audio files, using the medium model:

whisper audio.flac audio.mp3 audio.wav --model medium

The default setting (which selects the small model) works well for transcribing English. To transcribe an audio file containing non-English speech, you can specify the language using the --language option:

whisper japanese.wav --language Japanese

Adding --task translate will translate the speech into English:

whisper japanese.wav --language Japanese --task translate

Run the following to view all available options:

whisper --help

See tokenizer.py for the list of all available languages.

Python usage

Transcription can also be performed within Python:

import whisper

model = whisper.load_model("base")
result = model.transcribe("audio.mp3")
print(result["text"])

Internally, the transcribe() method reads the entire file and processes the audio with a sliding 30-second window, performing autoregressive sequence-to-sequence predictions on each window.

Below is an example usage of whisper.detect_language() and whisper.decode() which provide lower-level access to the model.

import whisper

model = whisper.load_model("base")

# load audio and pad/trim it to fit 30 seconds
audio = whisper.load_audio("audio.mp3")
audio = whisper.pad_or_trim(audio)

# make log-Mel spectrogram and move to the same device as the model
mel = whisper.log_mel_spectrogram(audio).to(model.device)

# detect the spoken language
_, probs = model.detect_language(mel)
print(f"Detected language: {max(probs, key=probs.get)}")

# decode the audio
options = whisper.DecodingOptions()
result = whisper.decode(model, mel, options)

# print the recognized text
print(result.text)

More examples

Please use the 🙌 Show and tell category in Discussions for sharing more example usages of Whisper and third-party extensions such as web demos, integrations with other tools, ports for different platforms, etc.

License

The code and the model weights of Whisper are released under the MIT License. See LICENSE for further details.