Core Audio API - Presentation

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

!