Annex 1 to AVC-398R

Documents for the Ipswich/London meeting
(27 October - 6 November 1992)

Normal Documents

	Note - [92/nnn] indicates MPEG92/nnn.

AVC-317R	REPORT OF THE SEVENTH MEETING IN NEW JERSEY AND RIO DE JANEIRO - 
	PART 1 (CHAIRMAN)
AVC-318R	REPORT OF THE SEVENTH MEETING IN NEW JERSEY AND RIO DE JANEIRO 
	PART 2 (CHAIRMAN)

These two documents report the outcome of the previous meeting in July 1992.

AVC-319	I.363 - B-ISDN ATM ADAPTATION LAYER (AAL) SPECIFICATION (SGXVIII) 

Specifications for AAL Type 1 are provided covering services, interaction with the management and control planes, functions of AAL Type 1, SAR syblayer and CS sublayer.  This revision will be approved in March 1993.

AVC-320	IVS BASELINE DOCUMENT (SGXVIII) 

This is a version revised at the June meeting of SGXVIII to align it with other I-series Recommendations and to reflect comments from other groups including this Experts Group.

AVC-321	I.371 - TRAFFIC CONTROL AND CONGESTION CONTROL IN B-ISDN (SGXVIII)

This Recommendation to be approved in March 1993 contains 1) specifications for traffic description and parameters; definition of peak cell rate, etc. and 2) functions and procedures for traffic control and congestion control; UPC/NPC, priority control and selective cell discard, etc.  

AVC-322	I.211 - B-ISDN SERVICE ASPECTS (SGXVIII) 

This Recommendation to be revised in March 1993 contains service classification, general description of network aspects, and video services and coding aspect.

AVC-355R	REPORT OF THE EIGHTH MEETING IN TARRYTOWN (CHAIRMAN) 

This meeting report presents the outcome of sole and joint sessions held in September 1992 to elaborate the video Test Model.

AVC-356	TEST MODEL 2 - REVISION 2 (TEST MODEL EDITING COMMITTEE)

Corrections and clarifications obtained at the Tarrytown meeting were incorporated.

AVC-357	STATUS REPORT ON ATM VIDEO CODING STANDARDIZATION, ISSUE 3
[92/576]	(EXPERTS GROUP)

Study results since September 1991 have been incorporated covering such items as picture format, video coding algorithm, VBR issue, multimedia multiplexing, network aspects, work plan.

AVC-358	EFFECT OF PSEUDO-RANDOM SIGNAL INSERTION IN LEAKY PREDICTION 
[92/577]	(JAPAN)

The solution for the limit cycle problem proposed in AVC-349 has been evaluated in three independent experiments, concluding that it solves the limit cycle problem without affecting coding efficiency, but "noisy background' still exists and need another fix.

AVC-359	SIMULATION RESULTS ON H.261 COMPATIBILITY AND SCIF (JAPAN) 
[92/578]

Compatibility experiments are reported where CIF pictures are used as base layer for coding CCIR601 or SCIF pictures.  It is suggested that up-sampling filter characteristics and frame rate of the base layer pictures may largely affect the coding performance.

AVC-360	STRUCTURED PACKING (JAPAN)
[92/579]

Four different proposals regarding the structured packing method are compared in the light of impacts on AAL and video syntax.  It is clarified that AAL should support an entry pointer as well as structured data handling, while an absolute addressing mechanism is the requirement for video syntax.  It is concluded that further consideration is needed for the best balance among cell loss resilience, AAL/bit stream generality, and coding efficiency.  Further study for multiplexed signals is also pointed out.

AVC-361	SPATIAL-DOMAIN COMPENSATION FOR CELL LOSS (JAPAN) 
[92/580]

Two methods for spatial localization of cell loss, structured packing and concealment, have been experimented for Flower Garden and Mobile & Calendar at 4 and 9 Mbit/s, concluding that they cooperatively contribute to the cell loss resilience, thus are necessary for sufficient cell loss compensation.

AVC-362	PICTURE HEADER OF SKIPPED PICTURES (JAPAN) 
[92/581]

It is proposed to send picture headers for skipped pictures by using a new picture_coding_type "skipped (S)" where there is no slice layer data included.

AVC-363	COMPARISON OF PICTURE DROPPING ORDER (JAPAN)
[92/582]

Based on picture skipping experiments for M=2 field pictures (Core Experiment H.2.5), it is concluded that there is no difference in subjective impression between coding order skipping and display order until the number of skipped pictures becomes 4, thus the former is suggested for its simpler rate control.

AVC-364	COMPARISON OF LEAKY PREDICTION AND INTRA SLICE ON CHANNEL HOPPING 
[92/583]	(JAPAN) 

Four ways of display after channel hopping are demonstrated to evaluate leaky prediction against intra slice; 1) leaky prediction with leak factor of 15/16, 2) blue picture display until a complete picture is refreshed, 3) last decoded picture display until a complete picture is refreshed, 4) blue picture being wiped by each intra slice.

AVC-365	HDTV CODING BY TEST MODEL 2 (JAPAN)
[92/584]

Experimental results are reported for coding of two HDTV sequences with luminance resolution of 1920 pels by 1024 lines at 30, 45 and 60 Mbit/s by applying TM2 straight (M=1, N=60).  Observation is made that 30 Mbit/s pictures contain some degradation (mostly granular noise) but 45 and 60 Mbit/s ones are almost free of artifacts.

AVC-366	UNDEFINED ITEMS IN COMPATIBILITY CODING (JAPAN) 
[92/585]

It is pointed out that in order to complete the embedded compatibility coding algorithm the following three items should be defined; 1) upsampling filters to generate higher resolution pictures, 2) selection of corresponding lower layer pictures when picture rates are different between higher and lower layers including the case that picture skipping is involved in the lower layer, 3) multiplexing method for the two layer signals.  Some discussion is also given to each item.

AVC-367	SIMULATION RESULTS ON SPATIO-TEMPORAL WEIGHTING (JAPAN)
[92/586]

Spatio-temporal weighting has been experimented for compatibility coding to obtain gains of 0.08 dB for Football and 0.25 dB for Flower Garden.  Prediction efficiency is improved by this weighting, but the overall coding gain is reduced by the need of transmitting motion vectors for the upper layer as well.  Memory bandwidth increase is also pointed out.  As a conclusion, it is stated that the current prediction from the base layer is sufficient if total performance is considered.

AVC-368	RE-SYNCHRONIZATION BY SLICE SIZE REDUCTION (JAPAN)
[92/587]

Coding efficiency for the reduced slice size (22, 11, 4, or 2 macroblocks per slice) has been measured to evaluate it as an alternative method for spatial localization of the cell loss to the structured packing.  It is reported that picture quality difference is distinguishable between 44 MB/slice and 4 MB/slice, but very small between 44MB/slice and 11 MB/slice.  It is suggested that if concealment works well for 11 MB/slice, this method is competitive with the structured packing in performance, thus preferable for its generic nature (i.e. no need for ATM specific solutions).

AVC-369	CLARIFICATION OF AAL TYPE 2 (JAPAN)

Two AAL alternatives for video signal support are discussed; one allows partially filled cells, the other does not.  The former tends to give better transmission efficiency while the latter guarantees the maximum transmission delay.  Study items are listed toward defining AAL fields.  Difficulty for bit error correction is also pointed out for the latter alternative.

AVC-370	MULTIMEDIA MULTIPLEXING METHOD OF AUDIOVISUAL COMMUNICATION (JAPAN)
[92/589]

Three configurations of the integrated services communication terminal are illustrated to draw attention to the multimedia multiplexing method; 1) multiplexing according to each application specific method at the sending side and multiple demultiplexers at the receiving side, 2) demultiplexing and remultiplexing at the sending side thus single demultiplexer at the receiving side, 3) common multiplexing and demultiplexing across different applications.  Some study items are listed for applying the MPEG system as a generic multimedia multiplexing in a communication terminal.

AVC-371	VIDEO SOURCE CLOCK RECOVERY (JAPAN)

Supplementary discussions are provided for the previous document AVC-336 which proposed a picture header field for transmitting the video source clock information; choice of the video source clock, network clock availability, frequency information transmitting interval, and consideration for retrieval from DSM.

AVC-372	VBR CODING UNDER USAGE PARAMETER CONTROL (JAPAN)

Measured data of video information generation and leaky bucket fullness are reported for VBR operation of an H.261 real-time hardware, where UPC is given as average rate regulation by a leaky bucket having different sizes.  It is concluded that to keep constant quality the bucket size should be of more than several tens of seconds in time while to obtain low delay it can be of several frames in time.

AVC-373	SUMMARY OF MULTIMEDIA MULTIPLEXING SYSTEMS (AUSTRALIA)

After discussing some items in the comparison table in AVC-129, particularly inclusion of CS multiplexing and benefits of cell-based multiplexing, an updated table is provided.  It is proposed to send a new version with further consideration in the Experts Group to SGXVIII for inclusion in the IVS Baseline Document.  Conveying the urgency of standardizing the network and signaling support of VC-based multiplexing to SGXI and XVIII is stressed.  It is also suggested that the Experts Group should keep the decision of a final multimedia multiplexing method open until the actual cost of VC-based multiplexing becomes clear.

AVC-374	CONTRIBUTION TO WORK PLAN (AUSTRALIA)

It is suggested that the Experts Group should take a phased approach to the development of the coding standard, taking into account the same approach adopted for the development of B-ISDN standards.  A table of work items is provided as a basis for a detailed work program of the Experts Group, listing design component, options, inputs required and impacts.  It is proposed that the Experts Group make this detailed work program and advise of the need for appropriate work in other groups, where necessary, to ensure that the overall system is developed.

AVC-375	RESULTS ON LAYERED CODER ERROR RESILIENCE (AUSTRALIAN UVC) 
[92/590]

Experimental results are reported for MPEG frequency scalable two layer coder with a single encoding loop in cell loss environments.  Three cases are compared in cell loss resilience; two layer coding with cell losses in the upper layer only, the same with cell losses in the base layer as well, an single layer coding, each layer has its own error concealment.  It is concluded that the layered coder without lower layer loss performs better than the single layer coder, as does the layered coder with lower layer loss as the overall cell loss ratio exceeds 0.001.

AVC-376	THEORETICAL STUDY OF THE USE OF PRIORITY (TELECOM AUSTRALIA)

Analysis for SNR performance of predictive coding is given for a statistically multiplexed situation.  Particularly cell loss resilient techniques such as leaky prediction and prioritization coupled with layered coding are found useful when the utilization is high.

AVC-377	PICTURE FORMATS FOR H.26X 
	(BELGIUM,FRANCE,ITSLY,NORWAY,NETHERLANDS,UK)

Due to the lack of information on dominant applications for H.26X, it is proposed that we should take a generic standard approach for H.26X and that CCITT activity should commence when appropriate on "application profiles" which will include picture formats, bit rates and many other parameters.  It is also noted that we must make high quality options available for those who need and can afford them, instead of providing only high quality solutions which are above customers' real needs and rejected for cost reasons.

AVC-378	VIDEO CLOCK RECOVERY (BELGIUM,FRANCE,ITSLY,NORWAY,NETHERLANDS,UK)

Four different methods for the video clock recovery are compared in hardware complexity and functionality; half buffer aim, buffer fill information, signaling encoder video clock frequency, and time stamps.  It is concluded to appear that the inclusion in the bit stream of data for the second and fourth methods offers the best route, leaving further study for verifying and extending the scope of the above analysis.

AVC-379	SPATIO-TEMPORAL WEIGHTED COMPATIBLE CODING CORE EXPERIMENT (UK) 
[92/591]

Experimental results are presented for the new selected weightings of the base layer prediction and the top layer prediction, reporting that gains of 0.19 dB, 0.12 dB and 0.16 dB have been obtained for P-pictures of Flower, Table and Calendar, respectively.

AVC-380	LAYERED CODING CELL LOSS EXPERIMENT (UK) 
[92/592]

Cell loss experiment results are presented for both one-layered simulcast coding and two-layered compatible coding.  Video data prioritization is employed; high priority is given to 1) all picture, group and sequence headers as well as all intra picture data of the simulcast signal and the compatible coding upper layer signal, and 2) the compatible base layer signal, while all other dada are set to low priority.  It has been shown that cell loss recovery using base layer data is more effective than cell loss recovery using previous picture data, and consequently two-layered coding is more resilient to cell loss than simulcast.

AVC-381	CELL LOSS EXPERIMENTS IN LAYERED CODING (PTT RESEARCH-NETHERLANDS)
[92/593]

Experimental results are presented for a two-layered MPEG-2 pure field coding scheme where concealment techniques based on the full resolution frame memories instead of the MPEG-1 frame memories are employed.  It has been shown that the concealment provides a high level of cell loss resilience while the picture quality is not acceptable without use of this concealment.

AVC-382	SIMULATION RESULTS OF SPATIAL-TEMPORAL WEIGHTING
[92/594]	(PTT RESEARCH-NETHERLANDS)

Experiments on the spatio-temporal weighting which were carried out according to TM2.1 for field-structure pictures show coding gain of 0.2 dB and more smooth images with less noise than the TM2.1 image.  It is also reported that simulation results show a gain in image quality (subjective impression and SNR) for compatible coding compared to simulcast.

AVC-383	TERMINAL CAPABILITY SETS FOR MULTIMEDIA SUPPORT 
	(NETHERLADS,UK,FRANCE,ITALY,BELGIUM,SWEDEN,FRG)

A notion of "capability set 0" and "capability set x" is introduced to sort out the multimedia multiplexing method issue.  The former stands for minimum configuration which every H.32X terminal must offer, thus allows interworking between any level of H.32X terminals, while the latter stands for the maximum configuration which is possible for a H.32X terminal, thus allows use of the cell multiplex method, the SAR multiplex method and the message multiplex method.  A lot of capability sets are possible between "capability set 0" and "capability set x", but they all must contain "capability set 0".

AVC-384	QUALITY CONSIDERATION ON VIDEO CODING ALGORITHM FOR SHORT TERM 
[92/595]	PSTN VIDEO TELEPHONE STANDARDISATION (NTR) 

Results from the work in COST211ter shows that significant gain in image quality can be made by changing the prediction of H.261, use of half-pel accuracy motion compensation instead of the loop filter.  It is also argued that a new coding algorithm should be close to H.261 with careful consideration of the effect on image quality.

AVC-385	CORE EXPERIMENT ON CELL LOSS RESILIENCE BY USING FREQUENCY
[92/596]	SCANNING (BELGACOM,SIEMENS,HHI)

A method of experimentation is given to compare the impacts of cell losses on both the block scanning (basic mode) and the frequency scanning with MUVLC techniques.  Global parameters and syntax modifications are described.

AVC-386	PROPOSAL FOR GENERAL ONE/TWO TIER MPEG TRANSPORT SYNTAX 
	(DSRC,TCE)

This document presents a specific MPEG-2 transport syntax, whose specification is based on a "structured packing" framework with fixed length packets of specifiable size.  The protocol consists of three sublayers; 1) network, 2) adaptation, 3) video service.  The network layer provides generic service multiplexing, scrambling and priority support for video delivery systems.  The video adaptation layer is for efficient packing of variable length MPEG data into fixed length packets, as well as for providing error management facilities.  The video service layer is an extension of the MPEG slice header concept, providing decoder resynchronization boundaries in the video bitstream.

AVC-387	DISCUSSION OF PRIORITY TRANSPORT OPTION FOR MPEG-2 (DSRC,TCE)

This document presents a discussion of how priority processing can be implemented in a practical MPEG-2 system and describes how the bitstreams can be synchronized (or resynchronized after data losses) at the decoder using the priority syntax.  Implementation of interfaces between the generic source coding/decoding and transmission media specific prioritizer/VLD, and synchronization of prioritized bitstreams with losses are also discussed.

AVC-388	LIAISON LETTER FROM CMTT/2-SRG TO CCITT WPXV/1 EG ACV (CMTT/2-SRG)

The updated version of the SRG activity report is brought to the attention of Experts Group.  The SRG has been focusing on the CTV/HDTV compatibility.

AVC-389	REGULATION SHAPING TECHNIQUE FOR VBR CODEC (FRANCE)

A traffic shaping technique consisting of four negotiated parameters (mean bit rate, peak bit rate, timescale during which the bit rate is constant and factor by which the bit rate can be increased or decreased from a timescale to another) has been experimented, using H.261.  It is reported that picture quality has been enhanced and the mean bit rate has been preserved during the communications.

AVC-390	RESULT OF THE SPATIAL SCALABILITY/COMPATIBILITY EXPERIMENT: H.261
[92/597]	BASED SPATIO TEMPORAL WEIGHTED COMPATIBLE MPEG2 CODING (FRANCE)

Experimental results are presented for the following four cases; 1) simulcast, 2) full compatible coding without spatio-temporal weighting, 3) spatio-temporal weighted field coding and 4) spatio-temporal weighted frame coding.  Bit rates are 1.15 Mbit/s for the base-layer and 2.85 Mbit/s for the upper-layer.  It is shown that the fourth compatible mode outperforms the other three compatible approaches with 1 dB gain compared to the simulcast for Flower Garden and Susie.

AVC-391	PUBLIC SWITCHED TELEPHONE NETWORK (PSTN) VIDEOPHONE (AT&T)
[92/588]

Design philosophy and some parameters of a PSTN videophone is given toward standardized videotelephony service, describing video coding algorithm, audio coding algorithm, modem algorithm, communication protocols and data transport services.

AVC-392	CORRECTION: ELIMINATING THE LIMIT CYCLE IN LEAKY PREDICTION (AT&T)
[92/598]

This document provides exact specifications for the limit cycle fix using a pseudo random signal which were proposed at the Tarrytown meeting.

AVC-393	EXPERIMENTAL RESULTS WITH LEAKY PREDICTION (AT&T)
[92/599]

Experimental results are presented on 1) equivalent quality with and without leak, 2) reduction of the noisy background, 3) cell loss resilience, 4) reduction of drift in the frequency scalable sequences, using TM2 frame-based coding with frame-based motion vectors at 4 Mbit/s.

AVC-394	TM2 SIMULATIONS AT 4 AND 2 MBIT/S COMPARED WITH MPEG-1 
	(DAIMLER BENZ - FRG)

Experimental results are presented for TM2 coding of the CCIR601 signal at 4 and 2 Mbit/s, and MPEG-1 coding of the SIF signal at 2 Mbit/s.  It is concluded that TM2 at 4 Mbit/s is expected to give absolutely acceptable results for a wide area of video storage, exchange and distribution, and that use of SIF for MPEG-1 coding causes significant loss of spatial resolution and heavy motion jerkiness compared to full resolution coding with TM2.

AVC-395	HDTV VIDEO CODING USING MPEG2-TM2 (ETRI-KOREA)
[92/752]

Experimental results are reported for coding of two HDTV sequences with luminance resolution of 1920 pels by 1024 lines at 25 and 35 Mbit/s by applying TM2 straight (M=3, N=15).  Observation is made that 25 Mbit/s pictures contain some quality degradation in the "Fashion Show" and granular noise in the "Locomotive" but 35 Mbit/s ones contain few artifacts.  It is also pointed out that color sharpness need be improved, e.g. by using 4:2:2  instead of 4:2:0.

AVC-396	THE MPEG SYSTEMS SPECIFICATION AND MULTIPLEX 
[92/549]	(S.MACINNIS, G.MORRISON)

A broad overview is given to salient general features of the MPEG system which provides 1) decoding and precisely synchronized presentation, 2) multiplexing of 0 to many audio and video streams, 3) a means for coded data buffers in decoders not to overflow nor underflow, 4) decoding after a random access with a reasonable short delay, 5) absolute time identification information for stream(s), 6) very low systems overhead.

AVC-397	REPORT OF RAPPORTEUR'S MEETING ON AAL TYPE 5
	(SPECIAL RAPPORTEUR SWP XVIII/8-5)

An updated text for AAL Type 5 specifications as well as a list of outstanding issues are provided as the output of Rapporteur's meeting held during 19-21 October 1992.

Temporary Documents

TD-1	Agenda for the sole sessions in Ipswich (Chairman)
TD-2	Available documents (Chairman)
TD-3	List of tape demonstrations (Chairman)
TD-4	Draft response to the liaison from SGXVIII on support of H.320 terminals in B-ISDN 
	(Chairman)
TD-5	Review of the Experts Group work plan (Chairman)
TD-6	Applications of video coding for B-ISDN (Japan)
TD-7	Comments on interworking between PSTN videophones and ISDN videophones (Japan)
TD-8	Draft fourth progress report (Chairman)
TD-9	Open issues (IVS Technical Session)
TD-10 	Report from the small group on leaky prediction (G. Bjoentegaard)
TD-11	ATM cell loss resilience framework (M. Biggar)
TD-12	H.261 compatibility (I. Park)
TD-13	Draft liaison statement to SGXVIII on VBR video coding advantage vs UPC time constant 
	(M. Yano)
TD-14	Proposed terms of reference for Experts Group for Very Low Bitrate Visual Telephony
	(G. Eude)
TD-15	Draft meeting report for the sole session in Ipswich (Chairman)