The Moving Picture Experts Group

MPEG 12 - Santa Clara

Date: 
Monday, 10 September 1990 to Friday, 14 September 1990
Venue: 
Marriott's Hotel
TBD
Sabta Clara, CA 99999
United States
Press release: 

Press Release - Status report of ISO MPEG

ISO/IEC JTC1/SC2/WG11 (MPEG) is a working group operating within Subcommittee 2 of the Joint ISO/IEC Technical Committee 1 on Information Technology.

The mandate of the group is the development of international standards for coded representation of moving pictures, associated audio and their combination when used for storage and retrieval on digital storage media.

The group is organised in several subgroups, among which are the Video, Audio and System Subgroups.

The current responsibility of the Video Subgroup is the development of a compression technique for coding of video signals at bitrates up to about 1.5 Mbit/s. In early 1989 fourteen proposals were submitted for this purpose. In October 1989 these candidate algorithms were evaluated using both subjective and objective measurements. The subjective evaluations were for the measurement of picture quality in various play modes while the objective tests measured several parameters including implementation complexity. The evaluations were carried out at JVC laboratories in Kurihama, Japan by MPEG members.

As a result it was recognised that most of the proposals had a large degree of commonality, so that it was possible to define a common environment for further development and optimisation of the coding algorithm.

After several steps of optimisation based on experiments carried out by members of the Video Subgroup, at the Santa Clara meeting on 10-14 September the experts defined the final algorithm.

The Audio Subgroup has responsibility for developing a compression technique for coding audio signals at bitrates of 192 kbit/s, 128 kbit/s, 96 kbit/s and 64 kbit/s per audio channel. In 1989, 14 proposals were submitted for this purpose. These were grouped into four clusters based on algorithmic similarities, resulting in one proposal by each cluster. The candidate algorithms are called ASPEC, ATAC, MUSICAM and SB/ADPCM.

In July 1990, these candidate algorithms were evaluated using both subjective and objective measurements. The subjective evaluations were for the measurement of audio quality while the objective tests measured several parameters including implementation complexity and coding delay. Formal subjective evaluations were carried out with the support of the Swedish Broadcasting Corporation. The objective tests were carried out by and ad-hoc group of MPEG members.

Due to hardware problems only two algorithms, ASPEC and MUSICAM, could be completely assessed. Both the ASPEC and MUSICAM proposals are very close in their basic structure and in their overall performance measured by scoring. The ASPEC proposal is slightly superior with respect to the audio quality, especially for lower bitrates, and the MUSICAM proposal is slightly superior with respect to implementation complexity and decoding delay. Hence a collaborative development of the draft audio coding standard between the ASPEC and MUSICAM groups has been approved and a new ad-hoc group called "Draft Development" has been set up. This new ad-hoc group consists of Prof. Musmann, University of Hannover, Chairman of the Audio Subgroup, Prof. Noll, Technical University of Berlin and four members of each of the ASPEC and MUSICAM groups. The collaborative development of the Draft allows improvements of the resulting coding algorithm by combining the most effective modules of the ASPEC and MUSICAM proposals. In view of the time schedule, it has been agreed to use MUSICAM as a basis for the low-complexity first layer of a multilayer coding algorithm and algorithmic refinements including contributions of ASPEC for the subsequent layers.

The responsibility of the System Subgroup is the development of an efficient technique for combining streams of coded audio and video suitable for multimedia environments. The work has progressed by collaborative development and evaluation of proposals by MPEG members.

At the Santa Clara meeting, WG11 recommended that the first draft of the proposed standard specifying the audio coding, the video coding and the technique to combine the digitally encoded audio visual signal be submitted for registration with SC2.

Press release file: