An AoIP codec for studio-to-studio link applications must be compatible with all common algorithms, such as MPEG 1/2 Layer 2/3, AAC LC, HEAACv1& v2, AAC-LD, G.711, G.722, E-aptX and PCM. It should also include a wide range of important features, such as Session Announcement Protocol (SAP) as well as Real-time Transfer Protocol (RTP/RTCP). Particularly, Session Initiation Protocol (SIP) ensures interoperability between AoIP codecs placed at different studio sites by establishing the connection and negotiating the algorithm.
REQUIREMENTS
In addition, latency control is extremely important for handling sophisticated broadcast environments, such as live broadcasts, audio description or in-ear monitoring. This allows synchronization up to a microsecond. If equipped with GPS or PTP, a sample accurate synchronization is also possible. To ensure best possible transmission quality, the device should provide functions for perfect redundancy management like dual streaming (IP packet-based redundancy) or exact audio sample synchronization of backup streams on different compression levels. Pro MPEG FEC is a feature for error correction by restoring of lost IP packets.