"Close Waveaudio" Command Closes Open Waveaudio Device

ID: Q77696

The information in this article applies to:

Microsoft Windows Software Development Kit (SDK) versions 3.0, 3.1

SUMMARY

In the Microsoft Windows environment, the "close waveaudio" MCI command string used with mciSendString() no longer closes all open waveaudio devices. Using the MCI command string "close waveaudio" closes only the device opened as "open waveaudio".

MORE INFORMATION

The previous behavior of the "close waveaudio" command string was to close all waveaudio devices in the system. This was considered "rude" behavior, because no application should be able to terminate another application's currently playing wave file. Therefore, this behavior was changed.

An application can terminate only the wave files that it has opened. Inside the application, "close waveaudio" closes only the device opened as "open waveaudio," not a waveaudio device opened with the "type waveaudio" parameter as follows:

open c:\mmwin\mmdata\laser.wav type waveaudio alias myfile

Therefore, a different approach is required to close all waveaudio devices in the application. Enumerate all waveaudio devices opened in that task and close them, as follows:


   sysinfo waveaudio quantity open     returns <n>
   sysinfo waveaudio name 1            returns name <1>
   close name 1
         .
         .
         .
   sysinfo waveaudio name n            returns name <n>
   close name n

NOTE: It is not necessary to close all open waveaudio files to play another one. The restriction is that only one waveaudio file can be playing at once (assuming only one waveaudio output device).

Additional query words: 3.00 no32bit 3.10

Keywords : kb16bitonly
Version : WINDOWS:3.0,3.1
Platform : WINDOWS
Issue type :