It enables similar applications to those the Plug-and-play specification allows.This is important in order to make best use of the features on the device identified.Each A2DP service, of possibly many, is designed to uni-directionally transfer an audio stream in up to 2 channel stereo, either to or from the Bluetooth host. It includes mandatory support for the low-complexity SBC codec (not to be confused with Bluetooth's voice-signal codecs such as CVSDM), and supports optionally MPEG-1 Part 3/MPEG-2 Part 3 (MP2 and MP3), MPEG-2 Part 7/MPEG-4 Part 3 (AAC and HE-AAC), and ATRAC, and is extensible to support manufacturer-defined codecs, such as apt X.
In order to use Bluetooth technology, a device must be compatible with the subset of Bluetooth profiles (often called services) necessary to use the desired services.
A Bluetooth profile is a specification regarding an aspect of Bluetooth-based wireless communication between devices.
For example, there are Hands-Free Profile (HFP) 1.5 implementations using both Bluetooth 2.0 and Bluetooth 1.2 core specifications.
The way a device uses Bluetooth technology depends on its profile capabilities.
The Audio/Video Remote Control Profile (AVRCP) is often used in conjunction with A2DP for remote control on devices such as headphones, car audio systems, or stand-alone speaker units.
These systems often also implement Headset (HSP) or Hands-Free (HFP) profiles for telephone calls, which may be used separately.It may be broken down into smaller pieces: Allows the initiator to remotely use a digital camera.For example, a user could place a camera on a tripod for a group photo, use their phone handset to check that everyone is in frame, and activate the shutter with the user in the photo.It resides on top of the Bluetooth Core Specification and (optionally) additional protocols.While the profile may use certain features of the core specification, specific versions of profiles are rarely tied to specific versions of the core specification.It also has the possibility for vendor-dependent extensions.