Datasets:
kkboy1
/
LeAudio

Dataset card Data Studio Files
xet
 Community
1
text
stringlengths
1
112
id ccid they were using for the unicast stream
in practice there are likely to be short gaps in transmission during this handover which will
be noticeable on the original acceptor s linked to the initiator whilst implementations can
try to minimise these it may be simpler to conceal them by adding a simple announcement to
the user to please wait while we move to audio sharing
chapter cap and csips
cap procedures for capture and rendering control
as wel l as the four sets of procedures for audio streams cap also ties together volume and
rendering control with five capture and rendering control procedures which are also self
explanatory
change volum e procedure
change volume offset procedure
change volume mute state procedure
microphone mute state procedure
change microphone gain settings procedure
other cap procedures
in addition to the audio stream and capture and rendering control procedures cap defines
a set of procedures which are used with the audio stream procedures listed above the first
one which we came across in the previous section is the coordinated set member discovery
procedure which is performed by an initiator before it sets up a unicast stream and by an
initiator or commander before they adjust the volume or capture settings on a coordinated
set once the members of a coordinated set are known cap always applies the csip
ordered access procedure prior to any other cap procedure the second is the distribute
broadcastcode procedure which defines how broadcastcodes are distributed for
encrypted private broadcast streams
connectio n establishment procedures
with the exception of broadcast use cases bluetooth le audio uses the same peripheral
connection procedures that are used for other le applications both for device discovery le
acl connection and bonding section of bap def ines the proce dures referring to the
relevant section in the core specification and provides recommended value s to use for scan
interval scan window and connection interval for quick setup and reduced power situations
these are all standard connection procedures defined in the generic access profile gap
so i wont spend any more time on them here
section of cap expands on the bap requirements with considerations for multi bond
situations where an acceptor is bonded with multiple initiators for example a phone and a
tv it also introduces two new modes which reflect the fact that both initiators and
acceptors can make connection decisions in order to support the concept of the sink led
journey these are the immediate need for audio relate d peripheral mode and the ready
for audio related peripheral mode
section cap the common audio profile
immediate need for audio related peripheral ina p mode
the ina p mode is use when an initiator needs to connect to an acceptor typically because
of a user action such as pressing a button or an external action such as an incoming phone
call as this is generally a high priority response the initiator should use t he quick setup
parameter values for connections from bap section the initiator should determine
whether the acceptor that responds is a member of a coordinated set and if so discover and
connect to all of the other set members if more than one acce ptor responds the initiator
should present the user with the available options
ready for audio related peripheral rap mode
the opposite case to ina p is the rap mode where an acceptor is looking fo r an initiator
it signals this by transmitting targeted announcements containing a context type describing
the use case that it wants supported if an initiator can support it it should attempt to connect
when in the ra p mode the initiator should us e the reduced power parameter values for
connections described in bap section once connected to the acceptor which was sending
targeted announcements the initiator should determine whether the acceptor is a member
of a coordinated set and if so dis cover and connect to all of the other set members
the range of initiator responses in rap or inap mode to different forms of announcement
is described in table of cap
coping with missing set members
there will be occasions when an initiator has read the coordinated set size characteristic of
a coordinated set member tried to locate the other members and discovered that some are
missing this could happen at the start of setting up an audio stream o r during the course
of a session when the initiator detects a link loss with one of the acceptors it may be because
one or more of them are physically missing out of range or their battery has died when this
occurs the initiator should try to find t he missing member but should not stop with the
connection process nor terminate any existing streams instead it should regularly try to find
the missing set members and add them back by re establishing the connection once they
have been discovered
an implementation may decide to adjust the content of a unicast audio stream if a member
is lost for example if your phone had been streaming a stereo music stream to a coordinated
set of left and right earbuds and the connection to one of them disappea rs it may decide to
replace the remaining stream with a down mixed mono stream however this behaviour is
not specified in bluetooth le audio and is implementation specific as is the retry cadence
and any timeouts for attempting to find missing coordin ated set members this should not
affect the context type as the use case remains the same
ooo
chapter cap and csips
the common audio profile is probably best summed up as a profile which says this is how
to connect and do this for all of the streams youre dealing with as such it pulls together
all of the other generic audio framework specifications providing a common set of
procedures for the top level profiles to use as more specifications are developed within gaf
cap will expand to include them
well come acr oss all of these cap procedures in the next few chapters on setting up unicast
and broadcast streams and capture and rendering control most developers will find
themselves working with these procedures rather than the underlying bap procedures as the
cap procedures are the ones which are referenced by the top level profiles however
understanding the bap procedures and the parameters used for setting up and managing
streams is a useful exercise to understand how everything fits together in the bluetoo th le
audio world thats what well do next
section cap the common audio profile
chapter setting up unicast audio streams
chapter setting up unicast audio streams
in this chapter well look at how to configure and set up unicast audio streams the four
main specifications which are involved at this stage are
pacs the published audio capabilities service
ascs the audio stream configuration service