mediabunny/docs/guide/input-formats.md

Input formats

Mediabunny supports a wide variety of commonly used container formats for reading input files. These input formats are used in two ways:

• When creating an Input, they are used to specify the list of supported container formats. See Creating a new input for more.
• Given an existing Input, its getFormat method returns the actual format of the file as an InputFormat.

Input format properties

Retrieve the full written name of the format like this:

inputFormat.name; // => 'MP4'

You can also retrieve the format's base MIME type:

inputFormat.mimeType; // => 'video/mp4'

If you want a file's full MIME type, which depends on track codecs, use getMimeType on Input instead.

Input format singletons

Since input formats don't require any additional configuration, each input format is directly available as an exported singleton instance:

import {
	MP4, // MP4 input format singleton
	QTFF, // QuickTime File Format input format singleton
	MATROSKA, // Matroska input format singleton
	WEBM, // WebM input format singleton
	MP3, // MP3 input format singleton
	WAVE, // WAVE input format singleton
	OGG, // Ogg input format singleton
	ADTS, // ADTS input format singleton
	FLAC, // FLAC input format singleton
} from 'mediabunny';

You can use these singletons when creating an input:

import { Input, MP3, WAVE, OGG } from 'mediabunny';

const input = new Input({
	formats: [MP3, WAVE, OGG],
	// ...
});

You can also use them for checking the actual format of an Input:

import { MP3 } from 'mediabunny';

const isMp3 = (await input.getFormat()) === MP3;

There is a special ALL_FORMATS constant exported by Mediabunny which contains every input format singleton. Use this constant if you want to support as many formats as possible:

import { Input, ALL_FORMATS } from 'mediabunny';

const input = new Input({
	formats: ALL_FORMATS,
	// ...
});

::: info Using ALL_FORMATS means demuxers for all formats must be included in the bundle, which can increase the bundle size significantly. Use it only if you need to support all formats. :::

Input format class hierarchy

In addition to singletons, input format classes are structured hierarchically:

• InputFormat (abstract)
  • IsobmffInputFormat (abstract)
    • Mp4InputFormat
    • QuickTimeInputFormat
  • MatroskaInputFormat
    • WebMInputFormat
  • Mp3InputFormat
  • WaveInputFormat
  • OggInputFormat
  • AdtsInputFormat
  • FlacInputFormat

This means you can also perform input format checks using instanceof instead of === comparisons. For example:

import { Mp3InputFormat } from 'mediabunny';

// Check if the file is MP3:
(await input.getFormat()) instanceof Mp3InputFormat;

// Check if the file is Matroska (MKV + WebM):
(await input.getFormat()) instanceof MatroskaInputFormat;

// Check if the file is MP4 or QuickTime:
(await input.getFormat()) instanceof IsobmffInputFormat;

::: info Well, actually 🤓☝️, the QuickTime File Format is technically not an instance of the ISO Base Media File Format (ISOBMFF) - instead, ISOBMFF is a standard originally inspired by QTFF. However, as the two are extremely similar and are used in the same way, we consider QTFF an instance of IsobmffInputFormat for convenience. :::