International organisation for standardisation

MPEG-7

The activities of the MPEG-7 group were reviewed and discussed in the video group. Further two input documents related to MPEG-7 image database query systems were presented and discussed.

Annex 7

Audio meeting report

Source: P. Schreiner, Chairman Audio Subgroup

D. Meares, Secretary Audio Subgroup

Opening of the meeting

The MPEG/Audio Subgroup meeting was held during the 44th meeting of WG11 in Dublin, Eire on 6 to 10 July 1998. The list of participants is given in Annex A-1. The Chairman welcomed the delegates to the meeting and outlined the work for the five days

Administrative matters

Approval of agenda

The agenda as presented in Annex A-II was discussed and approved.

Tokyo meeting report

The Audio Subgroup portion of the Tokyo meeting report, March 1998, had been previously distributed by email. Comments had been returned demonstrating the need for clarification of what was written. These changes were made and entered into the record of that meeting. The resultant report was therefore approved.

Allocation of contributions

All contributions were listed (see Annex A-VI) and allocated to the agenda. All contributions directly related to the Subgroup except for the MPEG-4 version 2 work on Environmental Spatialisation were presented in task group discussions, or in Audio plenary. Several relevant documents from Test, Systems and Requirements were brought to the attention of the group by the secretary.

Communications from the Chair

The Chairman summarised the detailed allocations and questions raised at the Chairman’s meeting held on the evening before the main meeting started. The majority of these, by design, were already in the agenda.

• 
  AAC licensing details were discussed. The matter was noted as improving but not yet totally resolved. The idea of a ‘one-stop’ licensing contact point was well received.
  
• 
  Synchronisation of TTSI and FBA
  
• 
  Concern on progress of CELP codecs
  
• 
  Update on MPEG-4 Version 1 and Version 2 Overviews
  
• 
  General concern over MPEG-4 patents c.f. MPEG-2 AAC patents. Need to start now.
  
• 
  The Convenor will be asking for publication of MPEG-4 IS on the Web.
  
• 
  MPEG needs an overall editor for Conformance
  
• 
  More work requested on watermarking within Audio.
  
• 
  “MPEG” has been trademarked but not by MPEG.
  
• 
  Name change being considered for MPEG-4.
  
• 
  MPEG-7 audio material needed - very short of examples.
  
• 
  New copyright release form for software needs to be considered.
  

Joint meetings

Joint meetings were scheduled with Test, Systems, ISG, and Requirements.

Report of ad hoc group activities

Some of the ad-hoc group reports had been presented in the opening MPEG Plenary, some had not. So all relevant details were presented to the Audio Subgroup and are recorded in the appropriate part of this report.

Received National Body Comments

The National Body comments were reviewed in the context of specific agenda items as reported below. Responses were drafted and passed to Liaison.

Liaison matters

Mr. Brandenburg kindly took care of the Liaison matters. He reported the issues to the Audio Subgroup and worked the Subgroup’s wishes into the responses. During the week, a further Liaison contact was made by email from DVB Technical Module to the Audio secretary requesting information on AAC test results. The matter was considered and a response was prepared by Mr. Meares. The report of the NADIB test results is being distributed through a variety of liaisons.

Temporary task group formation

To accomplish the large number of tasks to be performed by the Audio Subgroup, 16 task groups were formed as indicated in . The results of each of the task groups were presented to and discussed by the entire Audio Subgroup, including iterations as necessary. The conclusions of the task groups are presented elsewhere in this report and are included in the output documents.

MPEG-2

IS 13818-3 BC

Technical Report IS 13818-5/Amd 1 (AMD July 98)

No further BC related work was required. The AMD was approved, document WG11/N2262.

IS13818-4/DAM1 (DAM Jul 98)

The USNB comment on a conformance bitstream for the use of MC_CRC in the extension stream was answered (It was later found that a new conformance bitstream will be required, and this will be addressed at the next meeting.)

IS 13818-7 AAC

Conformance 13818-4 /DAM 1 (DAM Jul 98)

The viability of some bitstreams was raised, as was the need for additional streams (with ADTS header or with DRC). Bugs fixing and provision of the new streams were confirmed, together with volunteers to do the work. The approved FPDAM is given in document WG11/N2258 and the DoC in document WG11/N2257.

The NB comments on Conformance were considered and resolutions offered. The viability of the LSB-criterion for conformance testing on non-sine sweep signals with psychoacoustic coders was questioned in the German NB comments. It was proposed that sine sweep only will be specified. Mr. Dietz also proposed the use of PEAQ, the newly proposed ITU-R objective measurement standard, as described in m3798. FhG have already used the system for their conformance work, and they have found it useful. However this is a new standard with commercial IPR, and the equipment is not yet available nor proven in practice. The problem appears to be that good sounding codecs may be thrown out by the LSB-criterion: the PEAQ criterion is not so stringent. The group agreed to delay the use of PEAQ until the commercial devices can be evaluated by MPEG members. MPEG-2 AAC will use sine-sweep/LSB only tests for conformance.

Mr. Toguri presented the conformance test report m3584 from Nippon Steel for Mr. Fukuchi. They had correctly decoded 10 bitstreams but had had difficulties with a further 8 bitstreams. This had been identified as a bug in the pulse coding process, which had been recently fixed, m3847. Double checks of these bitstreams with the bugs fixed will be completed shortly after this meeting.

Technical Report 13818-5 /DAM 1 (AMD Jul 98)

A few bugs had been identified and were being corrected. The missing encoder codes to active pulse coding were provided by m3855. It was additionally decided that the Technical Report would be kept in line with the Technical Corrigendum, 13818-7/Cor 1. To this end, DRC and other features of the corrigendum are being added to the Technical Report. The workplan for the final work on Convergence and Technical Report is given in document WG11/N2298. The AMD was approved, document WG11/N2262. The disposition of comments is given in document WG11/N2261.

IS 13818-7 COR1 (COR Jul 98)

Mr. Johnston chaired a task group during the week that worked on all outstanding details in the corrigendum. It was noted that the recent editing of the draft introduced PNS syntax into 13818-7, which was essentially against the intentions of the Tokyo meeting. Mr. Herre noted that what the group had tried to do was generate a text which was common between MPEG-2 and MPEG-4 in a fashion that generated no PNS elements for MPEG-2 but did generate PNS elements in the bitstream for MPEG-4. It was agreed that the essence of the intention had been that no existing MPEG-2 hardware or bitstreams would be invalidated by these changes. The PNS element in the MPEG-2 AAC will appear only in the informative text. It was determined that objects were already defined in MPEG-4 for AAC without PNS ensuring that backward compatibility of MPEG-4 to MPEG-2 AAC exists. Mr. Johnston prepared the DoC and the revised corrigendum as given in document WG11/N2265 and 2266.

IS 13818-7COR1 (AAC Dynamic Range Control Issue)

Mr. Schreiner reported the progress at the ad-hoc meeting on AAC DRC. Not enough work was done to allow a report of verification testing completion but editing continued throughout this meeting and will be finalised within two weeks of the end of the Dublin meeting. Mr. Fellers prepared a workplan showing how the remaining proving tests could be completed within two weeks of the end of the Dublin meeting, document WG11/N2270

AAC licensing actions

The issue of delay in agreements on AAC licensing was discussed in Plenary. Mr. Brandenburg reported the fairly recent, rapid progress on this matter. Four companies (AT&T, Dolby, FhG, and Sony) had signed an agreement on exploitation and licensing, and the essence of the licensing charges were provided to interested parties during the meeting. However, it was observed that if the licensing arrangement for AAC took two years (approx.), the negotiations relating to MPEG-4 Audio are likely to be even more difficult and time consuming. Discussion was initiated during the meeting to try to ensure as rapid a period of negotiations as possible.