Signal Processing: Image Communication 15 (1999) 95}126 Scalable Internet video using MPEG-4 Hayder Radha*, Yingwei Chen, Kavitha Parthasarathy, Robert Cohen Philips Research, 345 Scarborough Rd, Briarcliw Manor, New York, 10510, USA Abstract Real-time streaming of audio-visual content over Internet Protocol (IP) based networks has enabled a wide range of multimedia applications. An Internet streaming solution has to provide real-time delivery and presentation of a continu- ous media content while compensating for the lack of Quality-of-Service (QoS) guarantees over the Internet. Due to the variation and unpredictability of bandwidth and other performance parameters (e.g. packet loss rate) over IP networks, in general, most of the proposed streaming solutions are based on some type of a data loss handling method and a layered video coding scheme. In this paper, we describe a real-time streaming solution suitable for non-delay-sensitive video applications such as video-on-demand and live TV viewing. The main aspects of our proposed streaming solution are: 1. An MPEG-4 based scalable video coding method using both a prediction-based base layer and a "ne-granular enhancement layer; 2. An integrated transport-decoder bu!er model with priority re-transmission for the recovery of lost packets, and continuous decoding and presentation of video. In addition to describing the above two aspects of our system, we also give an overview of a recent activity within MPEG-4 video on the development of a "ne-granular-scalability coding tool for streaming applications. Results for the performance of our scalable video coding scheme and the re-transmission mechanism are also presented. The latter results are based on actual testing conducted over Internet sessions used for streaming MPEG-4 video in real- time.  Published by 1999 Elsevier Science B.V. All rights reserved. 1. Introduction Real-time streaming of multimedia content over Internet Protocol (IP) networks has evolved as one of the major technology areas in recent years. A wide range of interactive and non-interactive multimedia Internet applications, such as news on- demand, live TV viewing, and video conferencing rely on end-to-end streaming solutions. In general, * Corresponding author. E-mail address: hmr@philabs.research.philips.com (H. Radha) streaming solutions are required to maintain real- time delivery and presentation of the multimedia content while compensating for the lack of Quality- of-Service (QoS) guarantees over IP networks. Therefore, any Internet streaming system has to take into consideration key network performance parameters such as bandwidth, end-to-end delay, delay variation, and packet loss rate. To compensate for the unpredictability and variability in bandwidth between the sender and receiver(s) over the Internet and Intranet net- works, many streaming solutions have resorted to variations of layered (or scalable) video cod- ing methods (see for example [22,24,25]). These 0923-5965/99/$ - see front matter  1999 Published by Elsevier Science B.V. All rights reserved. PII: S 0 9 2 3 - 5 9 6 5 ( 9 9 ) 0 0 0 2 6 - 0