webtv-ISSUE-39 (Bob L.): TV Services and Media Transport Mapping [MPTF]

webtv-ISSUE-39 (Bob L.): TV Services and Media Transport Mapping [MPTF]

http://www.w3.org/2011/webtv/track/issues/39

Raised by: Bob Lund
On product: MPTF

Specifications need to be developed that define how in-band video, audio and text tracks are detected and mapped to the relevant HTML5 APIs and objects.

Table 1 shows the scope of TV Services across media transport format mapping.

{| border="1" align="center"
|+'''Table 1 TV Services and Media Transport'''
| 
|MPEG2 TS
|MPEG4 ISOBMFF
|DASH MPD
|Other Manifest File Types
|-
|ETV triggers
|
|
|
|
|-
|Ad insertion
|
|
|
|
|-
|Content advisories
|
|
|
|
|-
|Secondary audio
|
|
|
|
|-
|Audio descriptions
|
|
|
|
|-
|Closed captions
|
|
|
|
|-
|Subtitles
|
|
|
|
|-
|}


Each row represents an application that consists of audio or application data in the media resource that needs to be exposed to the application via the HTML5 track or media elements. Each column represents a type of media transport that could be relevant. In addition to MPEG2 TS, we anticipate the development of an in-band mechanism for MPEG4 fragmented file format (used in DASH). There are also specifications at various stages of development for out-of-band track types referenced in DASH MPD and other manifest file formats, such as HTTP live streaming.

Each of these cells will define:

# How the audio/application data is carried and found in the media resource
# What formats should be recognized
# How the information in the tracks gets mapped to the appropriate HTML5 API/DOM objects

Received on Thursday, 11 August 2011 19:39:12 UTC