BlueZ API as BAP Server gives us the ISO interval, instead of the SDU
interval, in the MediaTransport.QoS.Interval property. They are not
necessarily the same. What we need is the SDU interval.
The SDU interval is the interval between packets the encoder outputs, so
it is determined by the codec configuration, and for LC3 is equal to the
frame duration.
Add codec method get_interval() that returns the correct interval, and
use it in iso-io.
Fix some sanity checks and add mtu check. Don't use
spa_return_val_if_fail here as it can spam stderr.
The buffer size check in codec_encode can't be hit.
Devices may advertise other values, but not certain they will work well
in duplex configuration.
E.g. my Samsung Galaxy Buds2 Pro emits buzzing sound with 48kHz duplex
input.
Don't believe QoS values recommended by the device, which may be
suboptimal. Instead, pick the values from the BAP v1.0.1 Table 5.2.
Link: https://github.com/bluez/bluez/issues/713
For multi-ASE configurations, BlueZ does the channel allocation itself,
and passes us the result in the ChannelAllocation parameter.
If it is present, don't do the allocation ourselves but use that value
instead.
If Supported_Max_Codec_Frames_Per_SDU is less than what is required by
Supported_Audio_Channel_Counts, override its value assuming the device
actually supports at least that. Needed for Creative Zen Hybrid Pro.
Fix default value for channel count bitmask.
Some devices appear to set Supported_Max_Codec_Frames_Per_SDU == 1 while
claiming they support two channels per stream, which is then not
possible.
In this case, limit the number of channels by the number of frames per
SDU when selecting.
Also adjust PAC sorting.
BlueZ now requires endpoints to set Locations/Context, so set them to
some sensible default values. These could in principle be made
configurable later.
Do BAP audio location selection properly in SelectProperties, now that
BlueZ provides the supported locations there. Remove a previous
workaround.
The audio location in SelectProperties determines the audio channel
allocation, which determines the channel positions.
Use the "high-reliability" values for QoS parameters instead of the
low-latency ones. Under some condition BlueZ does not pass on the
endpoint QoS values to us, in which case we may end up selecting bad
latency.
If BAP codec configuration is mono channel with unspecified location,
set the channel position from transport location.
This in principle should be set in SelectProperties, but currently BlueZ
doesn't tell us that yet there, so we hack it up later on.
The number of channels is determined by Audio_Channel_Allocation.
One frame block contains all channels. (BAP v1.0.1 Sec. 4.2)
Fix the handling of frame blocks and counting of numbers of channels. We
support and configure only one frame block per packet.
Consider omitted Audio_Channel_Allocation to indicate MONO stream (see
BAP v1.0.1 Sec 4.3.2).
BlueZ may send multiple PACs in the capabilities delimited by zero LTV.
Handle this case by selecting the "best" one.
The configuration size may also for BAP generally be different from PAC
size.
The codec may need to take into account endpoint preferred QoS values,
so parse this information and pass it to the codec's get_qos.
All the QoS struct values need to be set, as otherwise BlueZ may pass
uninitialized zero values over the air, which devices can reject. This
does not apply to CIG/CIS ids, which are automatically allocated by
default.
Fixes connecting to nrf5340 devkit, which requires a valid TargetLatency
value.
