International organisation for standardisation

MPEG-4 (Version 1)

FCD

The video group evaluated the NB comments issued on the FCD of MPEG-4 and discussed possible reactions to NB’s. Based on the outcome of the discussions and taking into account a number of minor technical problems found in the FCD a “Study on CD” document was issued.

Software Integration and Verification

A schedule for continuing software integration and verification was developed. A detailed plan for testing combination of tools was issue. The schedule targets to complete the bitstream verification by the time the FCD ballot takes place.

Additional Tools for Version 1

The video group reviewed the possibility to include additional tools into Version 1 (GMC, ¼ pel MC and BBM). Considering that the verification and software integration of existing tools is already at a very late stage, the decision was taken to not support an integration of new tools into Version 1.

Verification Tests

The results of the “Error Resilience” verification tests were reviewed. In general the results showed an excellent performance of the new tools developed under experimental testing conditions. For a bitrate of 128 kbit/s one test sequence showed unexpected artifacts. Further experimentation prior to the next meeting will clarify the possible testing conditions for a new verification test.

Further verification tests are under preparation for content-based coding and scalable coding of video. The test for content-based coding is targeted for the time prior to the November meeting in Israel. For this purpose a number of test conditions were defined and a number of test sequences are to be prepared prior to the US meeting in October. Outstanding questions to be clarified are:

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  Rate control for comparison of stand alone MPEG-1 and MPEG-4 coding efficiency
  
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  Implementation of multi-layer rate control for object-based coding of video
  

At the October US MPEG meeting pre-screening of the results will be done in the video group. Based on the outcome a decision will be taken whether verification tests will be performed prior to the Nov. Israel meeting or not.

A further subject for verification tests addresses scalable coding of video. Also for this subject new results will be presented at the next meeting.

Conformance

Good progress was made for the specification of conformance of MPEG-4 video coding systems. The discussions in the video group identified that MPEG-4 video conformance could be defined in a similar way as specified for MPEG-2. However, the availability of official software could introduce a new way of measuring conformance against a benchmark. Further discussions need to take place to clarify the issues. A new version of the MPEG-4 conformance working draft was released.

MPEG-4 (Version 2)

Tools to be supported

A major item under discussion was the decision on tools to be supported by Version 2. Based on input and tape viewing a number of decisions were taken. Based on NB resolutions and Tokyo meeting plenary resolutions it was agreed to assist the following tools that were already under discussion for Version 1:

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  GMC
  
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  ¼ pel MC
  
• 
  BBM
  
• 
  SADCT
  

Additional tools agreed to be supported by version 2 are listed below. These tools provide new functionalities compared to version 1:

• 
  Newpred (Error Resilience)
  
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  Object Spatial Scalability (Scalability)
  
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  Multiple Alpha Channel Coding (Various)
  
• 
  Error Resilience for Still Texture Coding (Error Resilience)
  
• 
  Scalable Arbitrary Shape for Texture Coding (Scalability)
  
• 
  Wavelet Tiling (Still Texture)
  

Output documents

A new version of the Working Draft for Version 2 was released.

MPEG-4 (Further)

Advanced Layered Coding

New proposals for advanced layered coding of video at high bit rates were reviewed. Based on a number of discussions and results generated between the Tokyo and the Dublin meeting some of the remaining questions on the techniques used in the proposed schemes were clarified. At the meeting the attempt was to separate pre-processing techniques used in the proposals from encoder issues required to be specified for standardization. A plan to verify the merits of the proposals in comparison to the established MPEG-2 and MPEG-4 scalable coding approaches was issued.

It was decided to discuss the proposals on Advanced Layered Coding in the context of MPEG-4 rather than for an amendment MPEG-2. The partners involved are Chromatics, NDS, Philips and U-Hannover.

Fine Granularity Scalability

Various partners expressed the desire to explore the MPEG-4 video system for internet video applications using fine granularity scalability approaches. It was identified that it is important in this context to understand the application context in more detail and to issue requirements accordingly. It was agreed that a fine granularity scalability system should be compatible to MPEG-4 Version 1 at the based layer. It should also be investigated whether it is already possible to provide this functionality with existing MPEG-4 technology already.

Studio Applications

The need to provide MPEG-4 solutions for very high quality applications was expressed by a number of MPEG member companies and NB comments. This would request the MPEG-4 video coding system to be extended to 4:2:2 and 4:4:4 formats with possible extension of the toolkit (scalability).
It was decided to identify the needs and technical issue both in the requirements group as well as in the video group. Further experimentation will be required to clarify the performance of MPEG-4 video at very high bit rates.