VTT Creator Backend

The backend part of a tool for creating and editing Web Video Text Track (WebVTT) files in your browser.

Check out the demo here.

The frontend app is currently more interesting. Check it out here.

Development

To get started, you'll need to create a file in the project root called .env.dev. This file needs to contain the following environment variables:

PORT=3001
NODE_ENV=development
GOOGLE_APPLICATION_CREDENTIALS=gcp_credentials.json

The PORT variable specifies what port the app will listen for requests on. If you set it to PORT=3002 for example, you can make requests to http://localhost:3002. Whatever you set this to, make sure the API_URL env var in the frontend application is pointing to the matching port.

The GOOGLE_APPLICATION_CREDENTIALS variable specifies the path to your Google Cloud Provider credentials file. If you plan to use Cloud Speech-to-Text to extract the text for your captions (which is kind of the point of the backend app), you'll need to create this file, put it somewhere in this project (root is a great spot ;)), and point this variable at it.

Once your environment is good to go, open a terminal window and navigate to the project root. Install dependencies with:

yarn

To run the app, run:

yarn start

Useful ffmpeg commands:

Extract first 6.5 seconds from an audio clip (https://stackoverflow.com/questions/7945747/how-can-you-only-extract-30-seconds-of-audio-using-ffmpeg)

ffmpeg -ss 0 -t 6.5 -i volvo_1.wav volvo_1_short.wav

Extract audio from video (https://ffmpeg.org/ffmpeg.html#Audio-Options)

ffmpeg -i "Volvo - Use the Code.mp4" -f wav -ar 44100 -ac 1 -sample_fmt s16 -vn volvo_1.wav