Handling Extended Command Messages and Data Structures

Extended command messages apply to particular device types such as animation devices. Device types with extended commands have capabilities that are not present in most types of MCI devices. Many of the required and basic commands are extended to use the capabilities of a device. MCI has the following types of extended commands:

Extended command messages for working with MCI element files

Extended command messages for device operation and positioning

Extended command messages for windowed video devices

The extended commands are summarized in this section. The details of operation are included in the MCI reference section of this chapter. Use these commands only if they apply to your device. If you do use an extended command, it must support the flags that are common to all devices using the command. If your device driver does not support an extended command, return MCIERR_UNRECOGNIZED_COMMAND.