|Microsoft DirectX 9.0|
By setting the GUID_DisableTempo and GUID_DisableTimeSig parameters on a track, you can disable the setting of tempo and time signature by a control segment. You might want to do this, for example, when you have set the tempo dynamically and don't want the primary segment to send tempo messages.
To re-enable the parameter, call one of the set-parameter methods with GUID_EnableTempo or GUID_EnableTimeSig as the rguidType parameter. You can also set these parameters to force a segment to send tempo messages even though it isn't the control segment, or to cause a secondary segment to send time signature messages.
It is also possible to disable and enable any track parameter by setting the configuration flags on the track. For more information, see Track Configuration.