Draft
 This page is not complete.
 This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
The TrackDefault interface provides a SourceBuffer with kind, label, and language information for tracks that do not contain this information in the initialization segments of a media chunk.
A TrackDefault object is provided to a SourceBuffer object by setting its SourceBuffer.trackDefaults property.
TrackDefault()TrackDefault object.TrackDefault.type Read only 
SourceBuffer's media segment data relates to (i.e. audio, video, or text track.)TrackDefault.byteStreamTrackID Read only 
SourceBuffer should apply to.TrackDefault.language Read only 
TrackDefault.label Read only 
TrackDefault.kinds Read only 
TBD
| Specification | Status | Comment | 
|---|---|---|
| Media Source Extensions The definition of 'TrackDefault' in that specification.  |  Recommendation | Initial definition. | 
| Desktop | ||||||
|---|---|---|---|---|---|---|
| Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | |
| Basic support | ? | Yes | No | ? | ? | ? | 
TrackDefault() constructor 
 | 
? | Yes | No | ? | ? | ? | 
byteStreamTrackID 
 | 
? | Yes | No | ? | ? | ? | 
kinds 
 | 
? | Yes | No | ? | ? | ? | 
label 
 | 
? | Yes | No | ? | ? | ? | 
language 
 | 
? | Yes | No | ? | ? | ? | 
type 
 | 
? | Yes | No | ? | ? | ? | 
| Mobile | |||||||
|---|---|---|---|---|---|---|---|
| Android webview | Chrome for Android | Edge Mobile | Firefox for Android | Opera for Android | iOS Safari | Samsung Internet | |
| Basic support | ? | ? | Yes | No | ? | No | ? | 
TrackDefault() constructor 
 | 
? | ? | Yes | No | ? | No | ? | 
byteStreamTrackID 
 | 
? | ? | Yes | No | ? | No | ? | 
kinds 
 | 
? | ? | Yes | No | ? | No | ? | 
label 
 | 
? | ? | Yes | No | ? | No | ? | 
language 
 | 
? | ? | Yes | No | ? | No | ? | 
type 
 | 
? | ? | Yes | No | ? | No | ? | 
    © 2005–2018 Mozilla Developer Network and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
    https://developer.mozilla.org/en-US/docs/Web/API/TrackDefault