Memory playlists can be used in recording scenarios. For example, MESSAGE instructions are useful for notifying the application of the progress of a recording operation. A message can be sent each time the filling of a buffer is completed.
Encasing several DATA statements inside a loop using either a LOOP or BRANCH instruction allows the playlist to function as a simple circular buffering scheme. The following is an example of circular buffering:
0: NOP
1: DATA...
2: MESSAGE...
3: DATA...
4: MESSAGE...
5: DATA...
6: MESSAGE...
7: BRANCH 0
If the playlist processor executes an EXIT statement while recording, this means the playlist is full. This situation is similar to a disk becoming full during a recording operation. An ERROR_END_OF_PLAYLIST error is generated by the playlist processor in the streaming subsystem. As the recording operation continues, additional data is lost. The media driver being used returns the MCIERR_TARGET_DEVICE_FULL to the application.
LOOP, CALL, and RETURN instructions are used for iterative playing operations. These instructions are not appropriate for a recording scenario because recorded data residing in the buffer would be overwritten by each iteration.