Audio/Video Transport WG Nan.Wang
Internet Draft Alcatel Shanghai Bell
Expires: January 26, 2010 July 26, 2009
Multi-Screen Application for SVC Video
draft-nanwang-avt-svc-multiscreen-00.txt
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Internet-Draft Multi-Screen Application for SVC Video July 2009
Abstract
This memo proposes a supplement to existing draft, RTP payload
Format for SVC Video. One new application, Multi-Screen is added.
SVC is very suitable for Multi-Screen application, which has some
different characteristics from the existing applications in the
current draft. This proposal provides a paradigm and addresses
potential issues and consideration.
1. Introduction
In this scenario, the term "Multi-Screen" and/or "Multi-Platform
Video" are synonymous as industry terms. In simple terms, they mean
communicating and enjoying media on any screen, device and at any
time, within a very seamless and compelling consumer experience.
Multi-Screen is more than TV, PC and Mobile.
2. Multi-Screen application
In multi-screen application, whether the video content are played
simultaneously in different screens will be decided according to the
user's requirements. This is the most difference between multi-
screen and the existing applications in the current draft[SVC].
Here is a typical multi-screen application scenario: one user
watches a live football game in his mobile-phone at afternoon,
and he requests a stored HD video of this game to his TV at night,
thus he and his family can view the HD(High definition) video of
this game using TV.
In multi-screen service, it is obviously that different media or
content being deployed to each of the appropriate screens will
occupy huge system resources. Currently the same content is
stored multiple times in different formats; this is expensive in
terms of storage and operations. Converting or trans-coding that
master video source into the various forms that are required to
realize multi-screen delivery by service providers is extremely
time consuming, and expensive for content creators/owners.
SVC can be used to solve the above problems. Screen matching for
a particular terminal device can be performed by selecting an
appropriate subset of the incoming SVC layers to transmit to the
particular device. For example, a system that uses spatial
scalability with three layers, base layer, enhancement layer one,
enhancement layer two. Decoding the base layer can support QCIF
size video which can be shown in the screen of mobile-phone;
decoding the base layer and enhancement layer one can support CIF
size video which can be shown in the screen of laptop or PC,
decoding the base layer and all enhancement layers can support 4CIF
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Internet-Draft Multi-Screen Application for SVC Video July 2009
size video which can be shown in the TV screen. In fact, the
payload format can also be designed to allow for screen-adaptability
in the mentioned senses. Thus, the converting or trans-coding
operations required to realize multi-screen delivery can be removed.
Moreover, it is not necessary that the same content is stored
multiple times in different formats.
As to the video transmission method, on one hand, if there is only
a single multi-screen user who requests video transmission to
his/her mobile phone, PC and TV, then IP multicast can be used to
transmit the base layer to his/her mobile phone, PC and TV. And
point to point transmission can be used to transmit the enhancement
layers to PC and TV. On the other hand, if there are many users of
multi-screen service, to save system resources, more flexible IP
multicast method can be performed to transmit the base layer and the
enhancement layers to the different screens.
When the transmissions to different screens are performed will be
decided according to the user's requirements. i.e., user can send
playing time requirements of different screens by using the OMA
interactivityMediaDocument, SIP message or SMS. Here should have
uniform input format of the playing time requirements.
3. References
[SVC] S.Wenger, et al, Internet-Draft, RTP Payload Format for
SVC Video-18, March, 2009.
4. Authors' Addresses
Nan Wang
Alcatel Shanghai Bell Co., Ltd.
388#, NingQiao Road, Pudong Jinqiao
Shanghai 201206 P.R. China
Phone: +86 (21) 5854-1240, ext.: 3415
Email: Nan.A.Wang@alcatel-sbell.com.cn
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Internet-Draft Multi-Screen Application for SVC Video July 2009