Data Transfer Using the Audio Compression Manager

If the Audio Compression Manager (ACM) is involved in the transfer, the data transfer model is as follows:

1. The client allocates the memory for the source and destination buffers. The ACMDM_STREAM_PREPARE message prepares the buffers.
2. The client sends both source and destination data blocks to the driver.
3. The driver processes the data blocks.
4. The driver (codec) returns the data to the client. The ACMDM_STREAM_UNPREPARE message releases the buffers, reversing the preparations made earlier by the ACMDM_STREAM_PREPARE message.
5. The client then frees the memory for both data blocks.