Pass zero-length packets to the codec. BAP/ISO may use these to indicate
missing data.
Fix A2DP codecs to not parse input with spa_return_val_if_fail, that's
meant for assertions. Just return -EINVAL directly, it's normal that
input data may contain garbage.
When the Bluetooth earphones claim to support AAC `MPEG-2 AAC LC` type only,
PipeWire encodes audio using MPEG-4 FDK-AAC profile which enables unsupported
Perceptual Noise Substitution (PNS) encoder feature.
Use AOT_MP2_AAC_LC pseudo-profile which is AOT_AAC_LC with PNS disabled.
Currently, the PipeWire daemon registers BlueZ LE Media Endpoints
with audio capabilities covering all settings defined in the BAP spec.
However, some scenarios might require the capabilities to be restricted
to specific configurations.
This adds a method to read LC3 codec specific capabilities from the
Wireplumber config file, and provide those settings when registering
Media Endpoint objects with BlueZ. If the values are not present in
the config file, all settings will be used by default.
Below is an example of how to set the LC3 capabilities in the config
file, to support the 16_2 setting from the BAP spec:
bluez5.bap-server-capabilities.rates = [16000]
bluez5.bap-server-capabilities.durations = [10]
bluez5.bap-server-capabilities.channels = [1, 2]
bluez5.bap-server-capabilities.framelen_min = 40
bluez5.bap-server-capabilities.framelen_max = 40
bluez5.bap-server-capabilities.max_frames = 2
Encoders and some decoders have additional internal latency that needs
to be accounted for.
This mostly matters for AAC (~40ms), as the other BT codecs have much
lower delays (~5ms).
Airpods don't follow the specification and set multiple bits in AAC
object type, including the ELD bit, but actually want AAC-LC. So check
the AOT in the right order.
The AAC-ELD support was not properly tested on devices. In theory it
should be OK, but it's untested.
Bump it down in priority so it won't be selected by default.
Also log info on FDK-AAC AAC-ELD support status.
uint32_t i;
for (i = 0; i < SPA_N_ELEMENTS(some_array); i++)
.. stuff with some_array[i].foo ...
becomes:
SPA_FOR_EACH_ELEMENT_VAR(some_array, p)
.. stuff with p->foo ..
Add a flag A2DP_CODEC_FLAG_SINK to incidate a sink endpoint.
Also enum_config and caps_preference_cmp may need to know whether the
codec is being configured for SRC or SNK. Also add the flags argument to
init_props.
Bump codec API version.
Codecs may need to fragment a single encoder frame across multiple
packets that are sent consecutively.
Allow codec->encode() to set need_flush=NEED_FLUSH_FRAGMENT, so that
sink should immediately call start_encode + encode with NULL input data,
to produce the next packet.
Previously, other return values than need_flush=1 were unused, so no
need to bump codec ABI for this.
There is a report (#1342) of a device setting multiple bits for AAC
object type in SetConfiguration, although this appears to be forbidden.
It's not completely clear if this was due to e.g. some BlueZ bug, but it
should be safe to be lax and try to guess what is wanted in such case,
instead of being strict, in case it was due to device bug.
Make easier to package A2DP codecs separately, by splitting each to a
separate SPA plugin. Adjust the code to not use a global variable for
the codec list.
The A2DP SPA interface API is in the bluez5 private headers, and not
exposed in installed SPA headers, as it's too close to the
implementation.
Mark some structures, arrays static/const at various places.
In some cases this prevents unnecessary initialization
when a function is entered.
All in all, the text segments across all shared
libraries are reduced by about 2 KiB. However,
the total size increases by about 2 KiB as well.
Let codec decides when rtp packet need to be sent (terminated by MTU size in most case).
LDAC encoding loop can now be terminated by reading if frame_num is written, no 'frame_count' updating is needed.
RTP payload fragmentation can now be implemented more easily based on this.
Initial Props value are parsed from device settings, further changes are triggered by 'set_param' on a2dp node.
Codec can then use props to tweak its transcoder.
