RTP Payload Format for MPEG-2 and MPEG-4 AAC Streams

摘要

This document describes a payload format for transportingMPEG-2/MPEG-4 AAC encoded data using RTP. MPEG-2/MPEG-4 AAC is arecent standard from ISO/IEC [1] [2] [3] for coding multi-channelaudio data. This payload format increases the packet loss resilienceof AAC coded audio transport above that of 'RTP Payload Format forMPEG1/MPEG2 Video (RFC 2250)' [7] by incorporating AAC properties intothe payload format. Supported features comprise fragmentation,interleaving, grouping, repair information and a predictabilityvector. The MPEG-2/MPEG-4 AAC bitstream format is not backwardscompatible with other MPEG-2 audio formats (e.g. MP3). Severalservices provided by RTP are beneficial for MPEG-2/MPEG-4 AAC encodeddata transport over the Internet. Additionally, the use of RTP allowsfor the synchronization of MPEG-2/MPEG-4 AAC with other real-timestreams.