McDewey

Callback Function An application can define a callback function in order to receive information about such things as operation completions, data transfers, and errors. Callback functions can be specified when an endpoint is created, when a stream callback is opened, and when a stream callback operation is initiated. If a callback operation is not specified a corresponding stream callback is invoked, if defined. If a stream callback is not specified a corresponding callback endpoint is invoked, if defined. If the callback function is defined, it is invoked for every operation that is initiated on a corresponding stream, endpoint, etc. Consideration should be given to the case where a callback function is defined as a method in an object that is dynamically created and destroyed. In that case destruction should not occur until all initiated operations are complete. Note Endpoint Callback Syntax typedef void (WINAPI *PRTPENDPOINTCALLBACK) ( HANDLE hEp, HANDLE hStream, DWORD dwError, PUCHAR pData, DWORD dwDataSize, LPVOID pUserData, bool bIsSilence, StreamDirection streamDir ); Parameters hEp Endpoint handle hStream Rtp stream handle dwError If not 0 (zero), indicates an error pData Endpoint handle dwDataSize Number of bytes received / transferred. pUserData Application data associated with an operation. Cisco Unified TAPI Developers Guide for Cisco Unified Communications Manager, Release 15 and SUs 442 Cisco TSP Media Driver Callback Function