ISO/IEC 14496-20:2006 Information technology - Coding of audio-visual objects - Part 20: Lightweight Application Scene Representation (LASeR) and Simple Aggregation Format (SAF)
This International Standard defines a scene description format (LASeR) and an aggregation format (SAF)
respectively suitable for representing and delivering rich-media services to resource-constrained devices such
as mobile phones.
LASeR aims at fulfilling all the requirements of rich-media services at the scene description level. LASeR
supports:
- an optimized set of objects inherited from SVG to describe rich-media scenes;
- a small set of key compatible extensions over SVG;
- the ability to encode and transmit a LASeR stream and then reconstruct SVG content;
- dynamic updating of the scene to achieve a reactive, smooth and continuous service;
- simple yet efficient compression to improve delivery and parsing times, as well as storage size, one of the
design goals being to allow both for a direct implementation of the SDL as documented, as well as for a
decoder compliant with ISO/IEC 23001-1 to decode the LASeR bitstream;
- an efficient interface with audio and visual streams with frame-accurate synchronization;
- use of any font format, including the OpenType industry standard; and
- easy conversion from other popular rich-media formats in order to leverage existing content and
developer communities.
Technology selection criteria for LASeR included compression efficiency, but also code and memory footprint
and performance. Other aims included: scalability, adaptability to the user context, extensibility of the format,
ability to define small profiles, feasibility of a J2ME implementation, error resilience and safety of
implementations.
SAF aims at fulfilling all the requirements of rich-media services at the interface between media/scene
description and existing transport protocols:
- simple aggregation of any type of stream;
- signaling of MPEG and non-MPEG streams;
- optimized packet headers for bandwidth-limited networks;
- easy mapping to popular streaming formats;
- cache management capability; and
- extensibility.
SAF has been designed to complement LASeR for simple, interactive services, bringing:
- efficient and dynamic packaging to cope with high latency networks;
- media interleaving; and
- synchronization support with a very low overhead.
This International Standard defines the usage of SAF for LASeR content. However, LASeR can be used
independently from SAF.
ISO/IEC 14496-20:2006 history
2010ISO/IEC 14496-20:2008/Amd 3:2010 Amendment 3 - Information technology -- Coding of audio-visual objects -- Part 20: Lightweight Application Scene Representation (LASeR) and Simple Aggregation Format (SAF) - Presentation and Modification of Structured Information (PMSI)
2010ISO/IEC 14496-20:2008/Amd 2:2010 Amendment 2 - Information technology -- Coding of audio-visual objects -- Part 20: Lightweight Application Scene Representation (LASeR) and Simple Aggregation Format (SAF) - Technology for scene adaptation
2010ISO/IEC 14496-20:2008/Cor 1:2010 Information technology — Coding of audio-visual objects — Part 20: Lightweight Application Scene Representation (LASeR) and Simple Aggregation Format (SAF) TECHNICAL CORRIGENDUM 1
2008ISO/IEC 14496-20:2006/Cor 2:2008 Information technology - Coding of audio-visual objects - Part 20: Lightweight Application Scene Representation (LASeR) and Simple Aggregation Format (SAF); Technical Corrigendum 2
2008ISO/IEC 14496-20:2006/Amd 1:2008 Information technology - Coding of audio-visual objects - Part 20: Lightweight Application Scene Representation (LASeR) and Simple Aggregation Format (SAF); Amendment 1: Extensions to support SVGT1.2
2008ISO/IEC 14496-20:2008 Information technology - Coding of audio-visual objects - Part 20: Lightweight Application Scene Representation (LASeR) and Simple Aggregation Format (SAF)
2007ISO/IEC 14496-20:2006/Cor 1:2007 Information technology - Coding of audio-visual objects - Part 20: Lightweight Application Scene Representation (LASeR) and Simple Aggregation Format (SAF); Technical Corrigendum 1
2006ISO/IEC 14496-20:2006 Information technology - Coding of audio-visual objects - Part 20: Lightweight Application Scene Representation (LASeR) and Simple Aggregation Format (SAF)