Given a parameter number and a time, return the parameter value at that time.
Parameters
- dwParam
- Zero based parameter number
- rtTimeStamp
- Time
Return Value
Calculated value for the specified time
Remarks
Parameters for DMO can be set in one of two ways. IMediaParams.SetParam can be used to set a parameter to a specific value. It is useful for setting values that aren't intended to change over time. There is also IMediaParams.AddEnvelope. This method can be use for things that change over time. For example, consider a parameter for adjusting the audio volume. You might want to be able to have the volume go from 0% to 150% over the first x seconds.You can easily support both by using this method. As you prepare to process buffers, take the timestamp that applies to that buffer, and call this method to get the desired value for that parameter at that that time.