Video over IP with forward error correction (FEC)

By Tam Do, Senior Technical Marketing Manager, Altera Corporation
June 01, 2007 -- CommsDesign

Distribution of video through cable plants and other private networks is moving to Video over IP. IP networks are used continuously with growing popularity for carrying video, voice and data in a triple play scheme. With this move comes the requirement of low cost solutions that must address the quality of service (QoS) due to packet corruption over long distance and multi-channel requirements. The same IP network that was designed for non-real time data is now tasked with handling high-speed real time video traffic to consumers. This article highlights a low cost Video over IP with Pro-MPEG FEC reference design utilizing an FPGA.

This low cost Video over IP implementation makes up a system bridging an MPEG transport stream (TS) data with an Ethernet-based Internet protocol (IP) network. The reference design can accept TS data from several inputs and encapsulate it for transmission over an Ethernet network. Figure 1 shows a typical Video over IP application in a real system. The design uses an industry standard user datagram protocol (UDP)/IP network encapsulation, with real time transport protocol (RTP) encapsulation, and Pro-MPEG Code of Practice #3 (CoP3) forward error correction (FEC) available as an option. The design supports both 100 megabits per second (Mbps) (full-duplex) and 1 gigabit per second (Gbps) Ethernet connections. By using hardware encapsulation, the design can achieve line-rate gigabit Ethernet performance with minimal transmission latency. The design can also accept traffic from an Ethernet network and recover the TS data. For RTP encapsulated data, the design includes a receiver buffer to absorb network jitter and correct for packet reordering and duplication. CoP3 FEC-based lost packet recovery is available as an option.

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