This page is the Main Page of the Wiki for the Media Resource In-band Tracks Community Group.

Overview

This group is developing a specification defining how user agents should expose in-band tracks as HTML5 media element video, audio and text tracks so that Web applications can access the in-band track information, through the media element, in a interoperable manner across user agent implementations.

The CG is currently exposing track content for the following media stream container types:

• MPEG-2 Transport Stream (MPEG-2 TS) (video/mp2t)
• ISO Base Media File Format (ISOBMFF aka MP4) (*/mp4)
• WebM (*/webm)
• OGG (*/ogg)
• DASH (application/dash+xml)

Other formats could be considered in the future, such as RTP streams.

Input Documents

CableLabs Specification

Additional CableLabs draft specification

Mapping MP4 tracks to WebVTT

OIPF Specification

Initial proposals and historical text that was integrated into the current specification is available here.

Requirements

This section specifies details beyond what is currently in HTML5 for exposing in-band tracks as HTML video, audio and text tracks.

Audio/Video Tracks

1. An Audio/VideoTrack must be created for each audio/video elementary stream that the UA can render.
2. The track order must be defined for all supported media resource container formats.
3. A method for determining the in-band audio/video stream's 'kind' attribute must be defined for all supported media resource container formats.
4. A method for determining the in-band audio/video stream's 'language' attribute must be defined for all supported media resource container formats.

Text Tracks

1. A method for determining which in-band streams are text tracks must be defined for all supported media resource container formats.
2. A method for determining the in-band data stream's 'kind' attribute must be defined for all supported media resource container formats.
3. A method for determining the DataCue attributes must be defined for all in-band data streams created as metadata TextTracks.

Track Metadata

1. Media resource metadata that describes the contents of an in-band video, audio or text track must be made available to a Web page.
2. A Web page must be provided with a way to associate in-band track metadata (made available as described in the previous step) with the proper VideoTrack, AudioTrack or TextTrack object.
3. The MIME type of the media resource containing in-band tracks must be available to a Web page so it knows how to parse the metadata for those in-band tracks.