Presentation on theme: "Core Audio API"— Presentation transcript
Slide1
Core Audio API
Emilis ArmonasSlide2
About
These APIs were new in Windows Vista and are not available in earlier versions of Windows
.
The core audio APIs provide the means for audio applications to access audio endpoint devices such as headphones and microphones
.
The core audio APIs serve as the foundation for higher-level audio APIs such as Microsoft DirectSound and the Windows multimedia
waveXxx
functions
Most applications communicate with the higher-level APIs, but some applications with special requirements might need to communicate directly with the core audio APIs.Slide3
Audio capabilities
Low-latency
Improved reliability
Improved security
Assignment
of particular system-wide roles
Software
abstraction of the audio endpoint
devicesSlide4
Higher-level APIs
DirectSound
DirectMusic
Windows multimedia
waveXxx
and
mixerXxx
functions
Media FoundationSlide5
Main Core Audio
APIs
Multimedia Device (MMDevice) API.
Clients
use this API to enumerate the audio endpoint devices in the system.
Windows Audio Session API (WASAPI).
Clients use this API to create and manage audio streams to and from audio endpoint devices.
DeviceTopology API.
Clients
use this API to directly access the topological features (for example, volume controls and multiplexers) that lie along the data paths inside hardware devices in audio adapters.
EndpointVolumeAPI.
Clients
use this API to directly access the volume controls on audio endpoint devices. This API is primarily used by applications that manage exclusive-mode audio streams.Slide6
Multimedia Device (MMDevice) API
The Windows Multimedia Device (
MMDevice
) API enables audio clients to discover
audio endpoint device
,
determine their capabilities, and create driver instances for those devices
.Slide7
Windows Audio Session API (WASAPI
)
The Windows Audio Session API (WASAPI) enables client applications to manage the flow of audio data between the application and
an
audio endpoint device.
Through the session abstraction, a WASAPI client can identify an audio stream as a member of a group of related audio
streams.
The
system can manage all of the streams in the session as a single unit.Slide8
DeviceTopology API
The
DeviceTopology
API provides client applications with the ability to traverse the functional hardware topologies of audio rendering and capture
devices.
Through
the interfaces and methods in the
DeviceTopology
API, clients can discover the functional subunits (for example, volume control) that lie along the data paths that lead to and from
audio enpoints devices
.
Clients
can traverse the internal topologies of both audio adapter devices and audio endpoint devices and step across the connections that link one device to anotherSlide9
EndpointVolumeAPI
The
EndpointVolume
API enables specialized clients to control and monitor the volume levels
of
audio endpoint devices.
Inappropriate
use of the
EndpointVolume
API can interfere with Windows audio policy and disrupt the user's system volume settings.Slide10
Thanks for your
attention
!
