Compressed Wave Formats

DirectSound does not currently support compressed wave formats. Applications should use the audio compression manager (ACM) functions, provided with the Win32 APIs in the Platform SDK, to convert compressed audio to pulse-code modulation (PCM) format before writing the data to a sound buffer. In fact, by locking a pointer to the sound-buffer memory and passing this pointer to the ACM, the data can be decoded directly to the sound buffer for maximum efficiency.