Video over DSL with LDGM codes for interactive applications

Abstract

Digital Subscriber Line (DSL) network access is subject to error bursts, which, for interactive video, can introduce unacceptable latencies if video packets need to be resent. If the video packets are protected against errors with Forward Error Correction (FEC) calculation of the application-layer channel codes themselves may also introduce additional latency. This paper proposes Low-Density Generator Codes (LDGM) rather than other popular codes because they are more suitable for interactive video streaming not only for their computational simplicity but also for their licensing advantage. The paper demonstrates that up to a 4 dB reduction in video distortion is achievable with LDGM Application Layer (AL) FEC. Telemedicine and video conferencing are typical target applications.