Organisation internationale de normalisation

5.2Task Group discussions

5.2.1MPEG-2 and MPEG-4 audio, conformance, reference software

MPEG-2 and MPEG-4

New Profiles

Takehiro Moriya, NTT, presented

m15660

Proposal for MPEG-4 ALS profile/levels

Takehiro Moriya Tilman Liebchen Yasushige Nakayama Toshiyuki Nomura Noboru Harada Yutaka Kamamoto

This proposes a profile that incorporates a limited set of tools from the ALS specification. A set of levels is defined that addresses scoping of complexity. A figure was presented that motivates the selected set of tools and limitations based on the compression/complexity tradeoff. Complexity figures were based on an ARM9 fixed-point platform and the presenter noted that BGMC coding was division intensive such that it is quite expensive on a fixed-point.

There was considerable discussion. Tilman Liebchen, LG, assured that ARIB is seriously moving ahead with this service. The Chair noted that ARIB’s interest would be limited to Level 1 and suggested at this time to limit the proposed profile to include only that level.

Yuriy Reznik, Qualcomm suggested that a liaison could be sent to IFPI requesting information on interest in other levels for this profile (e.g. for portable player or consumer music archives).

It was the consensus of the group to draft an output document and to review it with the Requirements group. Given a favourable review, this will be issued as a Working Draft of a new amendment to 14496-3.

Yuriy Reznik, Qualcomm, presented

m15715

Comment on proposal for MPEG-4 ALS profiles/levels

Yuriy Reznik

This contribution noted that the complexity figures in the previous contribution, m15660, appear to be inconsistent with those in N7686, “Verification Report on MPEG-4 ALS.” These differences will be resolved in a task group that will report back to the Audio Subgroup.

Ralf Geiger, FhG, presented

m15628

Proposed new profile for MPEG-4 SLS

Ralf Geiger Ralph Sperschneider Virgilio Bacigalupo

This contribution requests the creation of a new profile “HD-AAC” that includes the MPEG-4 AAC-LC and SLS audio object types and supports up to two channels, 96 kHz sampling rate and 24 bit word length. The tools in the SLS audio object type were restricted to exclude CBAC. Eunmi Oh, Samsung, questioned the complexity figures provided by FhG to motivate exclusion of the CBAC tools and indicated that Samsung internal results are different. The Chair requested that FhG make available to the group its complexity data and that, if possible, Samsung make available to the group its complexity data.

The Chair proposes that the profile definition, as in the contribution, be reviewed by Requirements. However, a consensus position in the Audio Subgroup on the complexity figures that motivate the tool exclusion must be reached prior to inclusion of the profile into a Working Draft of a new amendment to 14496-3.