How video upload works

Video uploads: Components and multiple language streams

What is a container?

A video file is a container that holds different components, including:

• Video codec

• Audio codec

• Captioning or video description

• Metadata

Codecs are algorithms used to compress video or audio streams. Please see this article for a list of supported video and audio codecs.

As shown in the diagram above, containers can also hold different media types, such as video and audio, as well as captions and metadata about the file.

Therefore, the term "file format" refers to the container format, which determines the file extension for normal video files, such as .avi, .mp4, and .mkv.

Video files (containers) with streams

The videos you upload will have one video and audio track, known as "streams."

You can have a video file with multiple audio streams, multiple subtitles in different languages, or multiple video descriptions (closed captioning for accessibility).

Creating a video file with multiple audio streams or subtitles

If you want to upload a video with:

• Multiple audio streams, the video file must contain multiple supported audio codecs.

• Multiple subtitles or video descriptions for accessibility purposes, the video file must contain multiple supported text or subtitle file formats (see a list here).

• Both multiple audio streams and multiple subtitles or video descriptions, the video file must contain both the supported audio codecs and supported text formats.

Please refer to your video editing software's manual or tutorial for information on using multiple audio codecs and subtitles or video descriptions.

Supported language codes

We support languages and language codes that adhere to the ISO 639-2 standard. You can find a complete list here.