(Continuation of Question 15/16)

Background and justification

Without regard to transport type (GSTN, N-ISDN, B-ISDN, LAN, Mobile), multimedia systems share a need for advanced media coding, such as:

• video or moving-image coding;
• still-image coding;
• audio coding;
• data compression and representation methods.

The goal of this Question is to produce advanced moving-image coding methods appropriate for conversational audio/visual services. However, moving-image coding should also consider applications for non-conversational services. This Question will focus on advanced techniques leading to significant quality and performance improvements. Video coding standards will be developed with sufficient flexibility to accommodate a diverse number of transport types (Internet, LAN, Mobile, N-ISDN, B-ISDN, GSTN, etc.). The Question will also include maintenance issues regarding existing video coding standards.

Two advanced video coding projects designated as H.263++ and H.26L have been developed. H.263++ is to improve the performance of H.263 by means of incremental extensions to the H.263 algorithm. H.26L will investigate new video coding algorithms with the objective of achieving a significant improvement in performance relative to the best available version of H.263. This Question will continue the work on both H.263+ and H.26L.

Study items

• Advanced coding methods in order to achieve the following objectives:
• reduction of real-time delay;
• improvements in compression efficiency;
• improvements in picture quality;
• robust operation in error-prone environments (e.g. non-guaranteed-bandwidth packet networks or mobile wireless communication);
• organization of the compressed data format to support packetization and streaming;
• methods to allow sub-rate streams to be easily mixed by MCUs or terminals, including intra only operation;
• temporal and spatial alignment of streams of varying coding;
• reduction of complexity;
• additional features such as object coding and multiview operation.
• Maintenance of existing H-series video coding Recommendations, including H.120, H.261, H.262|ISO/IEC13818-2 and H.263.
• Variable Bit Rate coding.
• Video coding needs for those using sign language and lip reading communication.
• Video bit rate reduction for compressed-digital to compressed-digital processing.
• The impact of colorimetry, video quality assessment, and quality control requirements on video codec development.
• Impact of downloaded video algorithm coding.

Specific task objectives with expected time-frame of completion

• H.263++: 2001.
• H.26L: 2002.

Relationships

• Other Questions dealing with multimedia communication, including SGs 16, 9, 11 (for mobility aspects), 13 (for IP aspects).
• ITU-T SG 12 for quality aspects.
• ISO/IEC JTC 1/SC 29 for harmonization of advanced coding objectives.
• IETF for packetization issues.
• Standard development organizations like 3GPP, 3GPP-2, WCC, etc.