Datasets:
kkboy1
/
LeAudio

Dataset card Data Studio Files
xet
 Community
1
text
stringlengths
1
112
the latter two options would usually require some level of user configuration of the speaker
but that is down to implementation
the sourceaudiolocations characteristic behaves in the same way although in most cases
it is likely to be limited to support of front left and front right if the acceptor supports a
single audio channel the initiator would assume that it is a mono microphone if it supports
two audio channels the initiator would assume it is a stereo microph one
the use of the sink and source audio location characteristics along with audio channel
counts provides a lot of flexibility for directing audio streams much of that is implied so
implementers need to think carefully abo ut the combination of parameters which they use
both the sink and source audio location characteristic values can change including during a
connection however should that happen during a connection the audio stream does not
need to be terminated th e new values would apply to the next stream establishment process
an application could also decide to change the streams for instance swapping the left and
right channel inputs between the left and right audio streams if a user wanted to mirror the
stereo effect because of the direction they were facing this is implementation specific and
outside the specifications
supported audio contexts
every acceptor needs to contain a supportedaudiocontexts characteristic which lists the
context type s which it supports this is generally a static list which will only change as a
result of a software update which changes the acceptors functionality
the name of supported audio cont exts is a little misleading what this characteristic does is
list the context type s ie the use cases for which the acceptor can make itself unavailable
in order to prevent any initiator trying to establish an audio stream for use cases that the
acceptor is not interested in support for each context type is optional other than the
unspecified context type which has to be supported in every supportedaudiocontexts
characteristic bap if an audio context is not marked as supported an initiator can
still attempt to establish a stream by mapping that context type to the unspecified context
type for its audio stream if the acceptor currently has unspecified set to available see
below it has no reason to reject that request as a result of receiving the audio stream an
acceptor may decide to change its available audio contexts setting for that context type
value for future requests
given this behaviour an acceptor should set every context type bit in the
supported audio conte xts characteristic where it thinks it will ever have a reason to make
that use case unavailable an audio sink is prohibited from being unavailable to everything
as the assigned numbers document prohibits an available audio contexts value of x
section pacs the published audio capabilities service
available audio context s
an acceptor uses the availableaudiocontexts characteristic to inform an initiator that it is
not available for specific context type s which it has claimed support for in the
supportedaudiocontexts characteristic to allow an initiator to continue with the audio
stream establishment process the context type of the audio stream the initiator wants to
set up must be shown as available in the availableaudiocontexts characteristic unlike the
suppo rtedaudiocontexts values which are static an acceptor may update its
availableaudiocontexts values at any time notifying connected initiators when it does so
to illustrate this figure shows a typical setting for the supportedaudiocontexts and
availableaudiocontexts characteristics
figure an example of settings for supportedaudiocont exts and availableaudiocontexts
in this example the acceptor supports unspecified which is mandatory along with
emergency alarms ringtone conversational instructional and media it shows all
of these as available if an initiator wa nts to start a stream with any of these context type s
the acceptor should accept it
if the initiator wanted to set up a stream to carry key press sounds which are covered by the
sound effects context type it can this is because the availableaudiocontexts bitmap
shows unspecified is available as long as unspecified is shown a s available in the
acceptors the initiator is allowed to map an unavailable context type that it wants to use to
unspecified in the properties of its streamingaudiocontexts metadata in which case
the acceptor must accept the audio stream
chapter setting up unicast audio streams
figure an example of the supportedaudiocontexts and availableaudiocontexts with fewer bits set
figure illustrates the value of setting context type bits in the supportedaudiocontexts
characteristic in this example emergency alarm and ringtone are supported but are not
currently marked as available in the availableaudiocontexts characteristic this m eans that
if an initiator tries to establish a stream associated with these context type s it will be rejected
by the acceptor as they are specifically set to unavailable if these bits had not been set as
supported the initiator could have mapped them to unspecified however in this case that
is not allowed as they are set as supported and not available however the initiator could
still remap streams associated with alerts notifications or any of the other unsupported
audio contexts to unsp ecified which the acceptor should accept
figure an example of settings for supportedaudiocontexts and availableaudiocontexts with
unspecified unavailable
finally figure shows an example where unspecified is indicated as unavailable
remember that unspecified always has to be supported setting unspecified to
unavaila ble prevents the initiator from mapping any other unavailable context type to
unspecified so in this case the acceptor is only available for audio streams that are
associated with instructional media or conversational
section ascs the audio stream control service
table illustrates this behaviour in terms of how an initiator interprets the settings
effectively the acceptor can set three options
allowing an initiator to proceed with establishing an audio stream
prohibiting it from starting the audio stream or
saying it doesnt care have a go
the combination of not supported and available is not allowed
supported
audio
contexts availa ble
audio
context s interpretation for initiator
b b audio stream context type may be mapped to unspecified
b b this combination is not allowed
b b an initiator shall not establish an audio stream with this
context type
b b an initiator may establish an audio stream with this context
type
table result of supported and availa ble bluetooth le audio context type settings
whilst the supportedaudiocontexts characteristic is vali d for all client s an acceptor may
expose different values of the availableaudiocontexts characteristics to different client s