PET FOCUSED EFFORT PROPOSAL from NPAC/Syracuse University

Focused Effort Title:	
	Enhanced Audio-Video Conferencing Support for the
	TangoInteractive Collaboratory System 

Thematic Area(s):  HPC Training and DoD User Productivity

PI Name: David Bernholdt

PI EMail Address: bernhold@npac.syr.edu

PI Telephone:	315 443 3857
PI Fax:		315 443 1973

Project Description:

Current audio/video agent (a.k.a. BuenaVista) of the TANGO Interactive
client has been designed to run over today's Internet. This
requirement prompted several design and implementation choices. As
BuenaVista is multiplatform, all encoding processes are performed
strictly in software. Since video encoding is CPU-intensive, the
system has built-in limitations of audio and video quality. These
limitations affect the maximal video frame rate (<10 fps), video size
(QCIF only), and audio sampling rate and computational complexity of
the codec. On the other hand, the system has been designed to be
real-time, i.e., to have as low latency as possible, consistent with
minimal audio quality requirements.

As public Internet is beefed up by new trunk lines, and as the MSRCs
move towards DREN and Internet2, the minimalistic design requirements
of the current BuenaVista may appear too restrictive. We hence propose
enhancement of the audio/video agent to support higher quality audio
and video. Implementation of such software will keep MSRCs abreast of
commercial technology developments and prepared to take advantage of
the better quality of service available on the new generation of
packet networks. In addition, the new tool, supporting a broader range
of qualities of audio and video streams, will be positioned to take
advantage of the emerging quality of service support and to support
adaptive QoS on future integrated services networks.

Currently, audio/video agent supports standard audio and video codecs,
such as GSM for audio and H261/H263 for video. The benfit of standard
coders is that they are also supported by a growing number of hardware
encoders. In particular, H263 hardware encoders are available for both
PC and UNIX platforms. Recently, the quality and robustness of the low
bitrate hardware video encoders reached the point at which they can be
safely deployed in mission critical information systems. Such a
deployment is hampared by lack of multi-platform, multiuser, standard
compliant videoconferencing software capable of supporting mixed
configurations of software and hardwarei-based encoders.

By designing current TANGO Interactive audio/video agent we have
demonstrated capability and expertise to implement multiplatform
videoconferencing solutions of industrial quality. We propose to take
the next step towards high-quality audio/video support for synchronous
distance learning and real-time videoconferencing by enhancing TANGO
audio/video agent to support hardware-based, standard commodity audio
and video encoders.

Benefits:

The enhancements outlined in this proposal will improve the quality of
videoconferncing using Tango where appropriate resources (computer
systems, network access) are available.  This, in turn, will enhance
the usefulness and user acceptance of electronic videoconferencing
tools for both training and collaboration.

Required Resources:
	Total: $150,000 over 12 months.	NPAC will share 50% of costs
	through its InfoMall (State of New York funded) activity.

	COST TO NAVO: $75,000 over 12 months

Deliverables:

The enhancements implemented in this project would result in a desktop
videoconferencing system with the following characteristics:

- multiplatform system supporting Wintel, SGI, and Sun workstations
- support for concurrent use of software and hardware encoders in
  session of arbitrary topology
- for workstations with hardware encoders, support for the video
  frame rates up to 15 fps and frame size up to SIF (320x244 pixels)
- 16 bit audio quality
- audio and video synchronized using RTP(Real Time Protocol) mechanism
- system latency not exceeding 1 second
- manual control of the media streams quality to ensure acceptable
  performance on a variety of networks
- support for both unicast and multicast