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MAS commissioning
Mixing different codecs
The system can mix participants with potentially different codecs in the same conference. To achieve this, the system transcodes the incoming streams into a common format, mixes, and then provides each participant with the correctly mixed audio. The system optimizes for multiple participants by transcoding the resulting mixed audio based upon a grouping of conference participants. If every participant uses identical codecs, at least three groups exist in a conference.
The first group contains the primary speaker, the second group contains the secondary speaker, and the third group contains the remainder of the participants. The groups describe the different versions of the mixed audio required in a conference. The first and second groups exist because the primary and secondary speakers do not hear their own voice, thus they must receive a different version of the audio than other participants. The third group is for all other participants who require the mixed audio of both active speakers.
The system must transcode all incoming audio streams to test for energy. However, if the basic conference algorithm is used, the system must transcode only the audio of each group and then replicate for each participant as needed. This conserves system resources. If multiple codecs exist in a single conference or if the premium conference algorithm is used, additional groups are required. The system can, therefore, optimize conferences with more than three participants because the additional system resources required for each participant includes transcoding the incoming audio stream and testing for energy. The additional participants are assigned to existing groups as needed so they receive the same audio as other group members.
The MAS can provide additional media processing functions for conferences on a global conference basis or for each participant. Optionally, the system can allocate a global announcement port that provides broadcast announcement capability to all participants. Additionally, the system can allocate a pseudo resource for each participant that enables the system to perform digit collection, speech recognition, and
Nortel Media Application Server 6.0 for AS 5300
Fundamentals
Release 6.0 03 June 2008
Copyright © 2008, Nortel Networks
