Using Hardware Mixing

Most sound cards support some level of hardware mixing if there is a DirectSound driver for the card. The following tips will allow you to make the most of hardware mixing:

• Use static buffers for sounds that you want to be mixed in hardware. DirectSound will attempt to use hardware mixing on static buffers.
• Create sound buffers first for the sounds you use the most. There is a limit to the number of buffers that can be mixed by hardware.
• At run time, use the IDirectSound::GetCaps method to determine what formats are supported by the sound-accelerator hardware and use only those formats if possible.
• To create a static buffer, specify the DSBCAPS_STATIC flag in the dwFlags member of the DSBUFFERDESC structure when you create a secondary buffer. You can also specify the DSBCAPS_LOCHARDWARE flag to force hardware mixing for a buffer, however, if you do this and resources for hardware mixing are not available, the IDirectSound::CreateSoundBuffer method will fail.