David William Singer

File format technology in JPEG 2000 enables flexible use of still and motion sequences

While there exist many different image file formats, the JPEG committee concluded that none of those formats addressed a majority of the needs of tomorrows complicated imaging applications. Many formats do not provide sufficient flexibility for the intelligent storage and maintenance of metadata. Others are very restrictive in terms of colorspace specification. Others provide flexibility, but with a very high cost because of complexity. The JPEG 2000 file format addresses these concerns by combining a simple binary container with flexible metadata architecture and a useful yet simple mechanism for encoding the colorspace of an image. This paper describes the binary format, metadata architecture, and colorspace encoding architecture of the JPEG 2000 file format. It also shows how this format can be used as the basis for more advanced applications, such as the upcoming motion JPEG 2000 standard.

Supporting constant-bit-rate-encoded MPEG-2 transport over local ATM networks

As one of the fast-developing switch-based high-speed networks, asynchronous transfer mode (ATM) is a promising network standard which may satisfy various requirements of multimedia computing. The Moving Picture Experts Group (MPEG) standard was designed to support full motion video stored on digital storage media at compression ratios up to 200:1. MPEG-2 is the second development phase of the MPEG standard and is designed for higher resolutions (including but not restricted to interlaced video) and higher bit rates (up to 20 Mbits/s). In this paper, the ATM adaptation layer type 5 (AAL-5) protocol was used to encapsulate constant-bit-rate-encoded MPEG-2 transport packets because of AAL-5’s general availability. However, there is a mismatch of size between MPEG-2’ s transport packets (188 bytes) and ATM AAL-5’s protocol data units (up to 65 535 bytes). In this paper, we examine and analyze four different packing schemes, 1TP, 2TP, nTP-Tight, and nTP-Loose (the scheme we propose), which encapsulated a certain number of MPEG-2 transport packets into one AAL-5 PDU. nTP-Loose scheme is proposed to have (1) better end-to-end performance than schemes 1TP and 2TP, (2) better error-recovery capability than scheme nTP-Tight, and (3) the same buffer requirement as scheme 2TP. A Power Macintosh ATM platform was used to identify the range of possible ways of packing MPEG-2 transport packets into one ATM AAL-5 PDU, when schemes with more than two MPEG-2 transport packets are chosen. Based on the test results, 10 or 12 MPEG-2 transport packets, which can yield throughputs of 70.36 and 78.98 Mbits/s, respectively, are recommended. Fast forward and backward playing of MPEG-2 movies (several times the video display speed) can be easily achieved via ATM networks.

An experimental ATM-based video-on-demand system on a Macintosh platform

Video-on-demand (VOD) systems can support multiple concurrent video accesses with guaranteed user-controlled quality of service (QoS). The growth of VOD systems is driven by the increasing need for distributed multimedia applications such as company training, distance learning, telemedicine, and home entertainment. We propose and demonstrate an ATM-based (asynchronous transfer mode) VOD system (including VOD servers, clients and connection networks) based on a Macintosh platform. ATM is a promising network standard which may satisfy various requirements of VOD systems. In this VOD system, time-based data are encoded and decoded using the MPEG (Moving Picture Experts Group) standard. Issues related to VOD system design, including the multimedia programming environment, the required system modification to support remote MPEG playback, ATM networking, process scheduling, and buffer management for both VOD servers and clients, are discussed and analyzed based on the Macintosh platform. A prototype VOD system is used to explore the design issues proposed. The Macintosh platform provided an efficient and jitter-free VOD system supporting MPEG movie playback through ATM networks.

Key to the success of asynchronous transfer mode: an application programming interface

Asynchronous transfer mode (ATM) networks are scalable via a wide variety of physical link speeds and can be run in both the local and wide areas. Bandwidth reservation and quality of service guarantees make ATM attractive to deliver multimedia information in real-time. Existing protocol suites can be extended. However, they do not give access to those characteristics. Therefore, applications demand an ATM application programming interface (API) to take advantage of those features. This paper covers a special syntax mapping of the ATM API services on top of X/Open Transport Interface (XTI) which is able to give applications access directly to the special quality and traffic services of an ATM network. A particular realization of the API on the XTI environment is proposed and implemented on the MacOS networking platform. It provides a flexible and modular design of the ATM networking. Finally, the paper concludes with one ATM-aware application (video on demand) which requires real-time streaming data.

JPEG 2000 file format : An imaging architecture for today and tomorrow

While there do exist many different image file formats, the JPEG committee felt that none of those formats addressed a majority of the needs of tomorrows complicated imaging applications. Many formats do not provide sufficient flexibility for the intelligent storage and maintenance of metadata. Others are very restrictive in terms of color encoding. Others provide flexibility, but with a very high cost due to complexity. The JPEG 2000 file format addresses these concerns by combining a simple binary container with a flexible metadata architecture and a useful yet simple mechanism for encoding the colorspace of an image. The format also looks toward the future, where the lines between still images, moving images, and multimedia become a blur, by providing simple hooks into other multimedia standards. This paper describes the binary format, metadata architecture, and colorspace encoding architecture of the JPEG 2000 file format. It also shows how this format can be used as the basis for more advanced applications, such as the upcoming motion JPEG 2000 standard.