Adding Hook-Switch Control to Skype VoIP software on Windows
Skype was the first VoIP application where I needed to integrate basic audio call Hook-Switch Control for a new USB telephone headset. Hook-Switch control was new to me but made sense, an incoming call should make the telephone headset ring, answering the call should enable audio and terminating the call ends the audio channel.
Skype has the largest share of PC-to-PC audio conferencing with, at one time, over half the market. Yahoo! Messenger had the second place, MSN Messenger third and GoogleTalk was only a blip with a handfull of users.
The integration of Skype with the new USB telephone headset was made easier by the excellent documentation by Skype, and a consistency across the various operating systems, including Windows, Mac OS X and Linux. Read more
Simple Windows Mixer Monitoring
Writing the simplest C++ class that monitors a Windows Mixer control for a specific audio device is as easy as creating a window. Our registered Windows procedure receives the MM_MIXM_??? messages through the applications GetMessage() loop. With the experience of writing a few classic Win32 based applications, most of what follows is a fresh reminder of the older Windows interface before COM objects.
Windows Vista changed the fundamentals of the System Sound interface creating an extensive COM object interface. The fundamentals of what is described here are directed towards Windows XP, Windows 2000 and Windows 2003 Server. Another article will describe the Windows Vista Mixer interface. Read more