In 2007, during the fever of DRM included in Windows Vista, the Windows Vista Team Blog was created to answer many questions about the problem. One of the questions answered the ability of VoIP software to perform echo cancellation when running on Windows Vista.
Here's what Nick White said in the FAQ:
Will echo cancellation be less effective for premium content?
We believe that Windows Vista provides applications with access to sufficient information to successfully create high-quality echo cancellation features.
What information does Windows Vista provide so that applications can create high-quality echo cancellation features?
Note. . Reading this operator, it seems that Windows Vista provides enough information to enable applications to successfully create high-quality echo cancellation features. Windows is supposedly providing this information through an API.
Echo cancellation works by fetching the playback output and subtracting it from the recorded microphone input.
Unfortunately, as MSDN notes , you cannot always reproduce reproducible results:
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