WebVTT Parser (PHP) Library

What is WebVTT?

For those unfamiliar, WebVTT (Web Video Text Tracks) is a standard format used for displaying subtitles, captions, or chapter markers in web videos. It’s widely supported by modern browsers like Chrome and Firefox and plays a crucial role in making video content accessible, especially for people with hearing impairments.

Why vtt-parser?

The vtt-parser library is a lightweight, dependency-free PHP tool designed to simplify working with WebVTT files.

Key Features

• Load and parse WebVTT files
• Extract timing information
• Validate subtitle structure

Getting Started

To start using vtt-parser, install it via Composer:

composer require webrium/vtt-parser

How to Use It

Let’s walk through a simple example to see how vtt-parser works in action.

Step 1: Include the Library

First, include Composer’s autoloader and import the TextParser class:

require 'vendor/autoload.php';
use Webrium\VttParser\TextParser;

Step 2: Load a WebVTT File

Create an instance of TextParser and load your WebVTT file using the openFile method:

$parser = new TextParser();
$filePath = '/path/to/your/subtitles.vtt';
$fileName = 'subtitles.vtt';

if ($parser->openFile($filePath, $fileName)) {
    // File loaded successfully
} else {
    // Handle error
}

Step 3: Parse the File

Use the parse method to extract subtitle data:

$subtitles = $parser->parse();

This returns an array of subtitle blocks, like so:

[
    [
        'time' => [
            'start' => '00:00:01.000',
            'end'   => '00:00:04.000'
        ],
        'text' => 'Hello, world!'
    ],
    // Other blocks...
]

Step 4: Validate the Structure

To check if your WebVTT file is properly formatted, use the textValidation method:

$validation = $parser->textValidation();
if ($validation['ok']) {
    echo "Subtitles are valid.";
} else {
    echo "Errors: " . implode(', ', $validation['errors']);
}

Use Cases:

• Developing subtitle editing tools
• Analyzing subtitle data for research