Merge pull request #643 from google/gbg/auracast-audio-io

auracast audio io

apps/auracast.py

@@ -18,14 +18,23 @@
 from __future__ import annotations
 
 import asyncio
+import asyncio.subprocess
+import collections
 import contextlib
 import dataclasses
 import functools
 import logging
 import os
-import wave
+import struct
-import itertools
+from typing import (
-from typing import cast, Any, AsyncGenerator, Coroutine, Dict, Optional, Tuple
+    cast,
+    Any,
+    AsyncGenerator,
+    Coroutine,
+    Deque,
+    Optional,
+    Tuple,
+)
 
 import click
 import pyee
@@ -33,8 +42,11 @@ import pyee
 try:
     import lc3  # type: ignore  # pylint: disable=E0401
 except ImportError as e:
-    raise ImportError("Try `python -m pip install \".[lc3]\"`.") from e
+    raise ImportError(
+        "Try `python -m pip install \"git+https://github.com/google/liblc3.git\"`."
+    ) from e
 
+from bumble.audio import io as audio_io
 from bumble.colors import color
 from bumble import company_ids
 from bumble import core
@@ -48,7 +60,6 @@ import bumble.device
 import bumble.transport
 import bumble.utils
 
-
 # -----------------------------------------------------------------------------
 # Logging
 # -----------------------------------------------------------------------------
@@ -62,6 +73,31 @@ AURACAST_DEFAULT_DEVICE_NAME = 'Bumble Auracast'
 AURACAST_DEFAULT_DEVICE_ADDRESS = hci.Address('F0:F1:F2:F3:F4:F5')
 AURACAST_DEFAULT_SYNC_TIMEOUT = 5.0
 AURACAST_DEFAULT_ATT_MTU = 256
+AURACAST_DEFAULT_FRAME_DURATION = 10000
+AURACAST_DEFAULT_SAMPLE_RATE = 48000
+AURACAST_DEFAULT_TRANSMIT_BITRATE = 80000
+
+
+# -----------------------------------------------------------------------------
+# Utils
+# -----------------------------------------------------------------------------
+def codec_config_string(
+    codec_config: bap.CodecSpecificConfiguration, indent: str
+) -> str:
+    lines = []
+    if codec_config.sampling_frequency is not None:
+        lines.append(f'Sampling Frequency: {codec_config.sampling_frequency.hz} hz')
+    if codec_config.frame_duration is not None:
+        lines.append(f'Frame Duration:     {codec_config.frame_duration.us} µs')
+    if codec_config.octets_per_codec_frame is not None:
+        lines.append(f'Frame Size:         {codec_config.octets_per_codec_frame} bytes')
+    if codec_config.codec_frames_per_sdu is not None:
+        lines.append(f'Frames Per SDU:     {codec_config.codec_frames_per_sdu}')
+    if codec_config.audio_channel_allocation is not None:
+        lines.append(
+            f'Audio Location:     {codec_config.audio_channel_allocation.name}'
+        )
+    return '\n'.join(indent + line for line in lines)
 
 
 # -----------------------------------------------------------------------------
@@ -156,18 +192,17 @@ class BroadcastScanner(pyee.EventEmitter):
             if self.public_broadcast_announcement:
                 print(
                     f'  {color("Features", "cyan")}:     '
-                    f'{self.public_broadcast_announcement.features}'
+                    f'{self.public_broadcast_announcement.features.name}'
-                )
-                print(
-                    f'  {color("Metadata", "cyan")}:     '
-                    f'{self.public_broadcast_announcement.metadata}'
                 )
+                print(f'  {color("Metadata", "cyan")}:')
+                print(self.public_broadcast_announcement.metadata.pretty_print('    '))
 
             if self.basic_audio_announcement:
                 print(color('  Audio:', 'cyan'))
                 print(
                     color('    Presentation Delay:', 'magenta'),
                     self.basic_audio_announcement.presentation_delay,
+                    "µs",
                 )
                 for subgroup in self.basic_audio_announcement.subgroups:
                     print(color('    Subgroup:', 'magenta'))
@@ -184,17 +219,22 @@ class BroadcastScanner(pyee.EventEmitter):
                         color('        Vendor Specific Codec ID:', 'green'),
                         subgroup.codec_id.vendor_specific_codec_id,
                     )
+                    print(color('      Codec Config:', 'yellow'))
                     print(
-                        color('      Codec Config:', 'yellow'),
+                        codec_config_string(
-                        subgroup.codec_specific_configuration,
+                            subgroup.codec_specific_configuration, '        '
+                        ),
                     )
-                    print(color('      Metadata:    ', 'yellow'), subgroup.metadata)
+                    print(color('      Metadata:    ', 'yellow'))
+                    print(subgroup.metadata.pretty_print('        '))
 
                     for bis in subgroup.bis:
                         print(color(f'      BIS [{bis.index}]:', 'yellow'))
+                        print(color('       Codec Config:', 'green'))
                         print(
-                            color('       Codec Config:', 'green'),
+                            codec_config_string(
-                            bis.codec_specific_configuration,
+                                bis.codec_specific_configuration, '         '
+                            ),
                         )
 
             if self.biginfo:
@@ -494,7 +534,7 @@ async def run_assist(
             except core.ProtocolError as error:
                 print(
                     color(
-                        f'!!! Failed to subscribe to Broadcast Receive State characteristic:',
+                        '!!! Failed to subscribe to Broadcast Receive State characteristic',
                         'red',
                     ),
                     error,
@@ -625,11 +665,20 @@ async def run_pair(transport: str, address: str) -> None:
 
 async def run_receive(
     transport: str,
-    broadcast_id: int,
+    broadcast_id: Optional[int],
+    output: str,
     broadcast_code: str | None,
     sync_timeout: float,
     subgroup_index: int,
 ) -> None:
+    # Run a pre-flight check for the output.
+    try:
+        if not audio_io.check_audio_output(output):
+            return
+    except ValueError as error:
+        print(error)
+        return
+
     async with create_device(transport) as device:
         if not device.supports_le_periodic_advertising:
             print(color('Periodic advertising not supported', 'red'))
@@ -643,7 +692,7 @@ async def run_receive(
         def on_new_broadcast(broadcast: BroadcastScanner.Broadcast) -> None:
             if scan_result.done():
                 return
-            if broadcast.broadcast_id == broadcast_id:
+            if broadcast_id is None or broadcast.broadcast_id == broadcast_id:
                 scan_result.set_result(broadcast)
 
         scanner.on('new_broadcast', on_new_broadcast)
@@ -694,57 +743,95 @@ async def run_receive(
             sample_rate_hz=sampling_frequency.hz,
             num_channels=num_bis,
         )
-        sdus = [b''] * num_bis
+        lc3_queues: list[Deque[bytes]] = [collections.deque() for i in range(num_bis)]
-        subprocess = await asyncio.create_subprocess_shell(
+        packet_stats = [0, 0]
-            f'stdbuf -i0 ffplay -ar {sampling_frequency.hz} -ac {num_bis} -f f32le pipe:0',
-            stdin=asyncio.subprocess.PIPE,
-            stdout=asyncio.subprocess.PIPE,
-            stderr=asyncio.subprocess.PIPE,
-        )
-        for i, bis_link in enumerate(big_sync.bis_links):
-            print(f'Setup ISO for BIS {bis_link.handle}')
 
-            def sink(index: int, packet: hci.HCI_IsoDataPacket):
+        audio_output = await audio_io.create_audio_output(output)
-                nonlocal sdus
+        # This try should be replaced with contextlib.aclosing() when python 3.9 is no
-                sdus[index] = packet.iso_sdu_fragment
+        # longer needed.
-                if all(sdus) and subprocess.stdin:
+        try:
-                    subprocess.stdin.write(decoder.decode(b''.join(sdus)).tobytes())
+            await audio_output.open(
-                    sdus = [b''] * num_bis
+                audio_io.PcmFormat(
-
+                    audio_io.PcmFormat.Endianness.LITTLE,
-            bis_link.sink = functools.partial(sink, i)
+                    audio_io.PcmFormat.SampleType.FLOAT32,
-            await bis_link.setup_data_path(
+                    sampling_frequency.hz,
-                direction=bis_link.Direction.CONTROLLER_TO_HOST
+                    num_bis,
+                )
             )
 
-        terminated = asyncio.Event()
+            def sink(queue: Deque[bytes], packet: hci.HCI_IsoDataPacket):
-        big_sync.on(big_sync.Event.TERMINATION, lambda _: terminated.set())
+                # TODO: re-assemble fragments and detect errors
-        await terminated.wait()
+                queue.append(packet.iso_sdu_fragment)
+
+                while all(lc3_queues):
+                    # This assumes SDUs contain one LC3 frame each, which may not
+                    # be correct for all cases. TODO: revisit this assumption.
+                    frame = b''.join([lc3_queue.popleft() for lc3_queue in lc3_queues])
+                    if not frame:
+                        print(color('!!! received empty frame', 'red'))
+                        continue
+
+                    packet_stats[0] += len(frame)
+                    packet_stats[1] += 1
+                    print(
+                        f'\rRECEIVED: {packet_stats[0]} bytes in '
+                        f'{packet_stats[1]} packets',
+                        end='',
+                    )
+
+                    try:
+                        pcm = decoder.decode(frame).tobytes()
+                    except lc3.BaseError as error:
+                        print(color(f'!!! LC3 decoding error: {error}'))
+                        continue
+
+                    audio_output.write(pcm)
+
+            for i, bis_link in enumerate(big_sync.bis_links):
+                print(f'Setup ISO for BIS {bis_link.handle}')
+                bis_link.sink = functools.partial(sink, lc3_queues[i])
+                await device.send_command(
+                    hci.HCI_LE_Setup_ISO_Data_Path_Command(
+                        connection_handle=bis_link.handle,
+                        data_path_direction=hci.HCI_LE_Setup_ISO_Data_Path_Command.Direction.CONTROLLER_TO_HOST,
+                        data_path_id=0,
+                        codec_id=hci.CodingFormat(codec_id=hci.CodecID.TRANSPARENT),
+                        controller_delay=0,
+                        codec_configuration=b'',
+                    ),
+                    check_result=True,
+                )
+
+            terminated = asyncio.Event()
+            big_sync.on(big_sync.Event.TERMINATION, lambda _: terminated.set())
+            await terminated.wait()
+        finally:
+            await audio_output.aclose()
 
 
-async def run_broadcast(
+async def run_transmit(
-    transport: str, broadcast_id: int, broadcast_code: str | None, wav_file_path: str
+    transport: str,
+    broadcast_id: int,
+    broadcast_code: str | None,
+    broadcast_name: str,
+    bitrate: int,
+    manufacturer_data: tuple[int, bytes] | None,
+    input: str,
+    input_format: str,
 ) -> None:
+    # Run a pre-flight check for the input.
+    try:
+        if not audio_io.check_audio_input(input):
+            return
+    except ValueError as error:
+        print(error)
+        return
+
     async with create_device(transport) as device:
         if not device.supports_le_periodic_advertising:
             print(color('Periodic advertising not supported', 'red'))
             return
 
-        with wave.open(wav_file_path, 'rb') as wav:
-            print('Encoding wav file into lc3...')
-            encoder = lc3.Encoder(
-                frame_duration_us=10000,
-                sample_rate_hz=48000,
-                num_channels=2,
-                input_sample_rate_hz=wav.getframerate(),
-            )
-            frames = list[bytes]()
-            while pcm := wav.readframes(encoder.get_frame_samples()):
-                frames.append(
-                    encoder.encode(pcm, num_bytes=200, bit_depth=wav.getsampwidth() * 8)
-                )
-            del encoder
-            print('Encoding complete.')
-
         basic_audio_announcement = bap.BasicAudioAnnouncement(
             presentation_delay=40000,
             subgroups=[
@@ -783,7 +870,23 @@ async def run_broadcast(
             ],
         )
         broadcast_audio_announcement = bap.BroadcastAudioAnnouncement(broadcast_id)
-        print('Start Advertising')
+
+        advertising_manufacturer_data = (
+            b''
+            if manufacturer_data is None
+            else bytes(
+                core.AdvertisingData(
+                    [
+                        (
+                            core.AdvertisingData.MANUFACTURER_SPECIFIC_DATA,
+                            struct.pack('<H', manufacturer_data[0])
+                            + manufacturer_data[1],
+                        )
+                    ]
+                )
+            )
+        )
+
         advertising_set = await device.create_advertising_set(
             advertising_parameters=bumble.device.AdvertisingParameters(
                 advertising_event_properties=bumble.device.AdvertisingEventProperties(
@@ -796,9 +899,10 @@ async def run_broadcast(
                 broadcast_audio_announcement.get_advertising_data()
                 + bytes(
                     core.AdvertisingData(
-                        [(core.AdvertisingData.BROADCAST_NAME, b'Bumble Auracast')]
+                        [(core.AdvertisingData.BROADCAST_NAME, broadcast_name.encode())]
                     )
                 )
+                + advertising_manufacturer_data
             ),
             periodic_advertising_parameters=bumble.device.PeriodicAdvertisingParameters(
                 periodic_advertising_interval_min=80,
@@ -808,47 +912,83 @@ async def run_broadcast(
             auto_restart=True,
             auto_start=True,
         )
+
         print('Start Periodic Advertising')
         await advertising_set.start_periodic()
-        print('Setup BIG')
-        big = await device.create_big(
-            advertising_set,
-            parameters=bumble.device.BigParameters(
-                num_bis=2,
-                sdu_interval=10000,
-                max_sdu=100,
-                max_transport_latency=65,
-                rtn=4,
-                broadcast_code=(
-                    bytes.fromhex(broadcast_code) if broadcast_code else None
-                ),
-            ),
-        )
-        print('Setup ISO Data Path')
 
-        def on_flow(packet_queue):
+        audio_input = await audio_io.create_audio_input(input, input_format)
+        pcm_format = await audio_input.open()
+        # This try should be replaced with contextlib.aclosing() when python 3.9 is no
+        # longer needed.
+        try:
+            if pcm_format.channels != 2:
+                print("Only 2 channels PCM configurations are supported")
+                return
+            if pcm_format.sample_type == audio_io.PcmFormat.SampleType.INT16:
+                pcm_bit_depth = 16
+            elif pcm_format.sample_type == audio_io.PcmFormat.SampleType.FLOAT32:
+                pcm_bit_depth = None
+            else:
+                print("Only INT16 and FLOAT32 sample types are supported")
+                return
+
+            encoder = lc3.Encoder(
+                frame_duration_us=AURACAST_DEFAULT_FRAME_DURATION,
+                sample_rate_hz=AURACAST_DEFAULT_SAMPLE_RATE,
+                num_channels=pcm_format.channels,
+                input_sample_rate_hz=pcm_format.sample_rate,
+            )
+            lc3_frame_samples = encoder.get_frame_samples()
+            lc3_frame_size = encoder.get_frame_bytes(bitrate)
             print(
-                f'\rPACKETS: pending={packet_queue.pending}, '
+                f'Encoding with {lc3_frame_samples} '
-                f'queued={packet_queue.queued}, completed={packet_queue.completed}',
+                f'PCM samples per {lc3_frame_size} byte frame'
-                end='',
             )
 
-        packet_queue = None
+            print('Setup BIG')
-        for bis_link in big.bis_links:
+            big = await device.create_big(
-            await bis_link.setup_data_path(
+                advertising_set,
-                direction=bis_link.Direction.HOST_TO_CONTROLLER
+                parameters=bumble.device.BigParameters(
+                    num_bis=pcm_format.channels,
+                    sdu_interval=AURACAST_DEFAULT_FRAME_DURATION,
+                    max_sdu=lc3_frame_size,
+                    max_transport_latency=65,
+                    rtn=4,
+                    broadcast_code=(
+                        bytes.fromhex(broadcast_code) if broadcast_code else None
+                    ),
+                ),
             )
-            if packet_queue is None:
-                packet_queue = bis_link.data_packet_queue
 
-        if packet_queue:
+            iso_queues = [
-            packet_queue.on('flow', lambda: on_flow(packet_queue))
+                bumble.device.IsoPacketStream(big.bis_links[0], 64),
+                bumble.device.IsoPacketStream(big.bis_links[1], 64),
+            ]
 
-        for frame in itertools.cycle(frames):
+            def on_flow():
-            mid = len(frame) // 2
+                data_packet_queue = iso_queues[0].data_packet_queue
-            big.bis_links[0].write(frame[:mid])
+                print(
-            big.bis_links[1].write(frame[mid:])
+                    f'\rPACKETS: pending={data_packet_queue.pending}, '
-            await asyncio.sleep(0.009)
+                    f'queued={data_packet_queue.queued}, '
+                    f'completed={data_packet_queue.completed}',
+                    end='',
+                )
+
+            iso_queues[0].data_packet_queue.on('flow', on_flow)
+
+            frame_count = 0
+            async for pcm_frame in audio_input.frames(lc3_frame_samples):
+                lc3_frame = encoder.encode(
+                    pcm_frame, num_bytes=2 * lc3_frame_size, bit_depth=pcm_bit_depth
+                )
+
+                mid = len(lc3_frame) // 2
+                await iso_queues[0].write(lc3_frame[:mid])
+                await iso_queues[1].write(lc3_frame[mid:])
+
+                frame_count += 1
+        finally:
+            await audio_input.aclose()
 
 
 def run_async(async_command: Coroutine) -> None:
@@ -917,7 +1057,7 @@ def scan(ctx, filter_duplicates, sync_timeout, transport):
 @click.argument('address')
 @click.pass_context
 def assist(ctx, broadcast_name, source_id, command, transport, address):
-    """Scan for broadcasts on behalf of a audio server"""
+    """Scan for broadcasts on behalf of an audio server"""
     run_async(run_assist(broadcast_name, source_id, command, transport, address))
 
 
@@ -932,7 +1072,24 @@ def pair(ctx, transport, address):
 
 @auracast.command('receive')
 @click.argument('transport')
-@click.argument('broadcast_id', type=int)
+@click.argument(
+    'broadcast_id',
+    type=int,
+    required=False,
+)
+@click.option(
+    '--output',
+    default='device',
+    help=(
+        "Audio output. "
+        "'device' -> use the host's default sound output device, "
+        "'device:<DEVICE_ID>' -> use one of the  host's sound output device "
+        "(specify 'device:?' to get a list of available sound output devices), "
+        "'stdout' -> send audio to stdout, "
+        "'file:<filename> -> write audio to a raw float32 PCM file, "
+        "'ffplay' -> pipe the audio to ffplay"
+    ),
+)
 @click.option(
     '--broadcast-code',
     metavar='BROADCAST_CODE',
@@ -954,16 +1111,57 @@ def pair(ctx, transport, address):
     help='Index of Subgroup',
 )
 @click.pass_context
-def receive(ctx, transport, broadcast_id, broadcast_code, sync_timeout, subgroup):
+def receive(
+    ctx,
+    transport,
+    broadcast_id,
+    output,
+    broadcast_code,
+    sync_timeout,
+    subgroup,
+):
     """Receive a broadcast source"""
     run_async(
-        run_receive(transport, broadcast_id, broadcast_code, sync_timeout, subgroup)
+        run_receive(
+            transport,
+            broadcast_id,
+            output,
+            broadcast_code,
+            sync_timeout,
+            subgroup,
+        )
     )
 
 
-@auracast.command('broadcast')
+@auracast.command('transmit')
 @click.argument('transport')
-@click.argument('wav_file_path', type=str)
+@click.option(
+    '--input',
+    required=True,
+    help=(
+        "Audio input. "
+        "'device' -> use the host's default sound input device, "
+        "'device:<DEVICE_ID>' -> use one of the host's sound input devices "
+        "(specify 'device:?' to get a list of available sound input devices), "
+        "'stdin' -> receive audio from stdin as int16 PCM, "
+        "'file:<filename> -> read audio from a .wav or raw int16 PCM file. "
+        "(The file: prefix may be omitted if the file path does not start with "
+        "the substring 'device:' or 'file:' and is not 'stdin')"
+    ),
+)
+@click.option(
+    '--input-format',
+    metavar="FORMAT",
+    default='auto',
+    help=(
+        "Audio input format. "
+        "Use 'auto' for .wav files, or for the default setting with the devices. "
+        "For other inputs, the format is specified as "
+        "<sample-type>,<sample-rate>,<channels> (supported <sample-type>: 'int16le' "
+        "for 16-bit signed integers with little-endian byte order or 'float32le' for "
+        "32-bit floating point with little-endian byte order)"
+    ),
+)
 @click.option(
     '--broadcast-id',
     metavar='BROADCAST_ID',
@@ -974,18 +1172,60 @@ def receive(ctx, transport, broadcast_id, broadcast_code, sync_timeout, subgroup
 @click.option(
     '--broadcast-code',
     metavar='BROADCAST_CODE',
-    type=str,
     help='Broadcast encryption code in hex format',
 )
+@click.option(
+    '--broadcast-name',
+    metavar='BROADCAST_NAME',
+    default='Bumble Auracast',
+    help='Broadcast name',
+)
+@click.option(
+    '--bitrate',
+    type=int,
+    default=AURACAST_DEFAULT_TRANSMIT_BITRATE,
+    help='Bitrate, per channel, in bps',
+)
+@click.option(
+    '--manufacturer-data',
+    metavar='VENDOR-ID:DATA-HEX',
+    help='Manufacturer data (specify as <vendor-id>:<data-hex>)',
+)
 @click.pass_context
-def broadcast(ctx, transport, broadcast_id, broadcast_code, wav_file_path):
+def transmit(
-    """Start a broadcast as a source."""
+    ctx,
+    transport,
+    broadcast_id,
+    broadcast_code,
+    manufacturer_data,
+    broadcast_name,
+    bitrate,
+    input,
+    input_format,
+):
+    """Transmit a broadcast source"""
+    if manufacturer_data:
+        vendor_id_str, data_hex = manufacturer_data.split(':')
+        vendor_id = int(vendor_id_str)
+        data = bytes.fromhex(data_hex)
+        manufacturer_data_tuple = (vendor_id, data)
+    else:
+        manufacturer_data_tuple = None
+
+    if (input == 'device' or input.startswith('device:')) and input_format == 'auto':
+        # Use a default format for device inputs
+        input_format = 'int16le,48000,1'
+
     run_async(
-        run_broadcast(
+        run_transmit(
             transport=transport,
             broadcast_id=broadcast_id,
             broadcast_code=broadcast_code,
-            wav_file_path=wav_file_path,
+            broadcast_name=broadcast_name,
+            bitrate=bitrate,
+            manufacturer_data=manufacturer_data_tuple,
+            input=input,
+            input_format=input_format,
         )
     )
 

apps/device_info.py

@@ -29,7 +29,9 @@ from bumble.gatt import Service
 from bumble.profiles.device_information_service import DeviceInformationServiceProxy
 from bumble.profiles.battery_service import BatteryServiceProxy
 from bumble.profiles.gap import GenericAccessServiceProxy
+from bumble.profiles.pacs import PublishedAudioCapabilitiesServiceProxy
 from bumble.profiles.tmap import TelephonyAndMediaAudioServiceProxy
+from bumble.profiles.vcs import VolumeControlServiceProxy
 from bumble.transport import open_transport_or_link
 
 
@@ -126,14 +128,52 @@ async def show_tmas(
     print(color('### Telephony And Media Audio Service', 'yellow'))
 
     if tmas.role:
-        print(
+        role = await tmas.role.read_value()
-            color('  Role:', 'green'),
+        print(color('  Role:', 'green'), role)
-            await tmas.role.read_value(),
-        )
 
     print()
 
 
+# -----------------------------------------------------------------------------
+async def show_pacs(pacs: PublishedAudioCapabilitiesServiceProxy) -> None:
+    print(color('### Published Audio Capabilities Service', 'yellow'))
+
+    contexts = await pacs.available_audio_contexts.read_value()
+    print(color('  Available Audio Contexts:', 'green'), contexts)
+
+    contexts = await pacs.supported_audio_contexts.read_value()
+    print(color('  Supported Audio Contexts:', 'green'), contexts)
+
+    if pacs.sink_pac:
+        pac = await pacs.sink_pac.read_value()
+        print(color('  Sink PAC:                ', 'green'), pac)
+
+    if pacs.sink_audio_locations:
+        audio_locations = await pacs.sink_audio_locations.read_value()
+        print(color('  Sink Audio Locations:    ', 'green'), audio_locations)
+
+    if pacs.source_pac:
+        pac = await pacs.source_pac.read_value()
+        print(color('  Source PAC:              ', 'green'), pac)
+
+    if pacs.source_audio_locations:
+        audio_locations = await pacs.source_audio_locations.read_value()
+        print(color('  Source Audio Locations:  ', 'green'), audio_locations)
+
+    print()
+
+
+# -----------------------------------------------------------------------------
+async def show_vcs(vcs: VolumeControlServiceProxy) -> None:
+    print(color('### Volume Control Service', 'yellow'))
+
+    volume_state = await vcs.volume_state.read_value()
+    print(color('  Volume State:', 'green'), volume_state)
+
+    volume_flags = await vcs.volume_flags.read_value()
+    print(color('  Volume Flags:', 'green'), volume_flags)
+
+
 # -----------------------------------------------------------------------------
 async def show_device_info(peer, done: Optional[asyncio.Future]) -> None:
     try:
@@ -161,6 +201,12 @@ async def show_device_info(peer, done: Optional[asyncio.Future]) -> None:
         if tmas := peer.create_service_proxy(TelephonyAndMediaAudioServiceProxy):
             await try_show(show_tmas, tmas)
 
+        if pacs := peer.create_service_proxy(PublishedAudioCapabilitiesServiceProxy):
+            await try_show(show_pacs, pacs)
+
+        if vcs := peer.create_service_proxy(VolumeControlServiceProxy):
+            await try_show(show_vcs, vcs)
+
         if done is not None:
             done.set_result(None)
     except asyncio.CancelledError:

bumble/audio/__init__.py

@@ -0,0 +1,17 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# -----------------------------------------------------------------------------
+# Imports
+# -----------------------------------------------------------------------------

bumble/audio/io.py

@@ -0,0 +1,553 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# -----------------------------------------------------------------------------
+# Imports
+# -----------------------------------------------------------------------------
+from __future__ import annotations
+
+import asyncio
+import abc
+from concurrent.futures import ThreadPoolExecutor
+import dataclasses
+import enum
+import logging
+import pathlib
+from typing import (
+    AsyncGenerator,
+    BinaryIO,
+    TYPE_CHECKING,
+)
+import sys
+import wave
+
+from bumble.colors import color
+
+if TYPE_CHECKING:
+    import sounddevice  # type: ignore[import-untyped]
+
+
+# -----------------------------------------------------------------------------
+# Logging
+# -----------------------------------------------------------------------------
+logger = logging.getLogger(__name__)
+
+
+# -----------------------------------------------------------------------------
+# Classes
+# -----------------------------------------------------------------------------
+@dataclasses.dataclass
+class PcmFormat:
+    class Endianness(enum.Enum):
+        LITTLE = 0
+        BIG = 1
+
+    class SampleType(enum.Enum):
+        FLOAT32 = 0
+        INT16 = 1
+
+    endianness: Endianness
+    sample_type: SampleType
+    sample_rate: int
+    channels: int
+
+    @classmethod
+    def from_str(cls, format_str: str) -> PcmFormat:
+        endianness = cls.Endianness.LITTLE  # Others not yet supported.
+        sample_type_str, sample_rate_str, channels_str = format_str.split(',')
+        if sample_type_str == 'int16le':
+            sample_type = cls.SampleType.INT16
+        elif sample_type_str == 'float32le':
+            sample_type = cls.SampleType.FLOAT32
+        else:
+            raise ValueError(f'sample type {sample_type_str} not supported')
+        sample_rate = int(sample_rate_str)
+        channels = int(channels_str)
+
+        return cls(endianness, sample_type, sample_rate, channels)
+
+    @property
+    def bytes_per_sample(self) -> int:
+        return 2 if self.sample_type == self.SampleType.INT16 else 4
+
+
+def check_audio_output(output: str) -> bool:
+    if output == 'device' or output.startswith('device:'):
+        try:
+            import sounddevice
+        except ImportError as exc:
+            raise ValueError(
+                'audio output not available (sounddevice python module not installed)'
+            ) from exc
+        except OSError as exc:
+            raise ValueError(
+                'audio output not available '
+                '(sounddevice python module failed to load: '
+                f'{exc})'
+            ) from exc
+
+        if output == 'device':
+            # Default device
+            return True
+
+        # Specific device
+        device = output[7:]
+        if device == '?':
+            print(color('Audio Devices:', 'yellow'))
+            for device_info in [
+                device_info
+                for device_info in sounddevice.query_devices()
+                if device_info['max_output_channels'] > 0
+            ]:
+                device_index = device_info['index']
+                is_default = (
+                    color(' [default]', 'green')
+                    if sounddevice.default.device[1] == device_index
+                    else ''
+                )
+                print(
+                    f'{color(device_index, "cyan")}: {device_info["name"]}{is_default}'
+                )
+            return False
+
+        try:
+            device_info = sounddevice.query_devices(int(device))
+        except sounddevice.PortAudioError as exc:
+            raise ValueError('No such audio device') from exc
+
+        if device_info['max_output_channels'] < 1:
+            raise ValueError(
+                f'Device {device} ({device_info["name"]}) does not have an output'
+            )
+
+    return True
+
+
+async def create_audio_output(output: str) -> AudioOutput:
+    if output == 'stdout':
+        return StreamAudioOutput(sys.stdout.buffer)
+
+    if output == 'device' or output.startswith('device:'):
+        device_name = '' if output == 'device' else output[7:]
+        return SoundDeviceAudioOutput(device_name)
+
+    if output == 'ffplay':
+        return SubprocessAudioOutput(
+            command=(
+                'ffplay -probesize 32 -fflags nobuffer -analyzeduration 0 '
+                '-ar {sample_rate} '
+                '-ch_layout {channel_layout} '
+                '-f f32le pipe:0'
+            )
+        )
+
+    if output.startswith('file:'):
+        return FileAudioOutput(output[5:])
+
+    raise ValueError('unsupported audio output')
+
+
+class AudioOutput(abc.ABC):
+    """Audio output to which PCM samples can be written."""
+
+    async def open(self, pcm_format: PcmFormat) -> None:
+        """Start the output."""
+
+    @abc.abstractmethod
+    def write(self, pcm_samples: bytes) -> None:
+        """Write PCM samples. Must not block."""
+
+    async def aclose(self) -> None:
+        """Close the output."""
+
+
+class ThreadedAudioOutput(AudioOutput):
+    """Base class for AudioOutput classes that may need to call blocking functions.
+
+    The actual writing is performed in a thread, so as to ensure that calling write()
+    does not block the caller.
+    """
+
+    def __init__(self) -> None:
+        self._thread_pool = ThreadPoolExecutor(1)
+        self._pcm_samples: asyncio.Queue[bytes] = asyncio.Queue()
+        self._write_task = asyncio.create_task(self._write_loop())
+
+    async def _write_loop(self) -> None:
+        while True:
+            pcm_samples = await self._pcm_samples.get()
+            await asyncio.get_running_loop().run_in_executor(
+                self._thread_pool, self._write, pcm_samples
+            )
+
+    @abc.abstractmethod
+    def _write(self, pcm_samples: bytes) -> None:
+        """This method does the actual writing and can block."""
+
+    def write(self, pcm_samples: bytes) -> None:
+        self._pcm_samples.put_nowait(pcm_samples)
+
+    def _close(self) -> None:
+        """This method does the actual closing and can block."""
+
+    async def aclose(self) -> None:
+        await asyncio.get_running_loop().run_in_executor(self._thread_pool, self._close)
+        self._write_task.cancel()
+        self._thread_pool.shutdown()
+
+
+class SoundDeviceAudioOutput(ThreadedAudioOutput):
+    def __init__(self, device_name: str) -> None:
+        super().__init__()
+        self._device = int(device_name) if device_name else None
+        self._stream: sounddevice.RawOutputStream | None = None
+
+    async def open(self, pcm_format: PcmFormat) -> None:
+        import sounddevice  # pylint: disable=import-error
+
+        self._stream = sounddevice.RawOutputStream(
+            samplerate=pcm_format.sample_rate,
+            device=self._device,
+            channels=pcm_format.channels,
+            dtype='float32',
+        )
+        self._stream.start()
+
+    def _write(self, pcm_samples: bytes) -> None:
+        if self._stream is None:
+            return
+
+        try:
+            self._stream.write(pcm_samples)
+        except Exception as error:
+            print(f'Sound device error: {error}')
+            raise
+
+    def _close(self):
+        self._stream.stop()
+        self._stream = None
+
+
+class StreamAudioOutput(ThreadedAudioOutput):
+    """AudioOutput where PCM samples are written to a stream that may block."""
+
+    def __init__(self, stream: BinaryIO) -> None:
+        super().__init__()
+        self._stream = stream
+
+    def _write(self, pcm_samples: bytes) -> None:
+        self._stream.write(pcm_samples)
+        self._stream.flush()
+
+
+class FileAudioOutput(StreamAudioOutput):
+    """AudioOutput where PCM samples are written to a file."""
+
+    def __init__(self, filename: str) -> None:
+        self._file = open(filename, "wb")
+        super().__init__(self._file)
+
+    async def shutdown(self):
+        self._file.close()
+        return await super().shutdown()
+
+
+class SubprocessAudioOutput(AudioOutput):
+    """AudioOutput where audio samples are written to a subprocess via stdin."""
+
+    def __init__(self, command: str) -> None:
+        self._command = command
+        self._subprocess: asyncio.subprocess.Process | None
+
+    async def open(self, pcm_format: PcmFormat) -> None:
+        if pcm_format.channels == 1:
+            channel_layout = 'mono'
+        elif pcm_format.channels == 2:
+            channel_layout = 'stereo'
+        else:
+            raise ValueError(f'{pcm_format.channels} channels not supported')
+
+        command = self._command.format(
+            sample_rate=pcm_format.sample_rate, channel_layout=channel_layout
+        )
+        self._subprocess = await asyncio.create_subprocess_shell(
+            command,
+            stdin=asyncio.subprocess.PIPE,
+            stdout=asyncio.subprocess.PIPE,
+            stderr=asyncio.subprocess.PIPE,
+        )
+
+    def write(self, pcm_samples: bytes) -> None:
+        if self._subprocess is None or self._subprocess.stdin is None:
+            return
+
+        self._subprocess.stdin.write(pcm_samples)
+
+    async def aclose(self):
+        if self._subprocess:
+            self._subprocess.terminate()
+
+
+def check_audio_input(input: str) -> bool:
+    if input == 'device' or input.startswith('device:'):
+        try:
+            import sounddevice  # pylint: disable=import-error
+        except ImportError as exc:
+            raise ValueError(
+                'audio input not available (sounddevice python module not installed)'
+            ) from exc
+        except OSError as exc:
+            raise ValueError(
+                'audio input not available '
+                '(sounddevice python module failed to load: '
+                f'{exc})'
+            ) from exc
+
+        if input == 'device':
+            # Default device
+            return True
+
+        # Specific device
+        device = input[7:]
+        if device == '?':
+            print(color('Audio Devices:', 'yellow'))
+            for device_info in [
+                device_info
+                for device_info in sounddevice.query_devices()
+                if device_info['max_input_channels'] > 0
+            ]:
+                device_index = device_info["index"]
+                is_mono = device_info['max_input_channels'] == 1
+                max_channels = color(f'[{"mono" if is_mono else "stereo"}]', 'cyan')
+                is_default = (
+                    color(' [default]', 'green')
+                    if sounddevice.default.device[0] == device_index
+                    else ''
+                )
+                print(
+                    f'{color(device_index, "cyan")}: {device_info["name"]}'
+                    f' {max_channels}{is_default}'
+                )
+            return False
+
+        try:
+            device_info = sounddevice.query_devices(int(device))
+        except sounddevice.PortAudioError as exc:
+            raise ValueError('No such audio device') from exc
+
+        if device_info['max_input_channels'] < 1:
+            raise ValueError(
+                f'Device {device} ({device_info["name"]}) does not have an input'
+            )
+
+    return True
+
+
+async def create_audio_input(input: str, input_format: str) -> AudioInput:
+    pcm_format: PcmFormat | None
+    if input_format == 'auto':
+        pcm_format = None
+    else:
+        pcm_format = PcmFormat.from_str(input_format)
+
+    if input == 'stdin':
+        if not pcm_format:
+            raise ValueError('input format details required for stdin')
+        return StreamAudioInput(sys.stdin.buffer, pcm_format)
+
+    if input == 'device' or input.startswith('device:'):
+        if not pcm_format:
+            raise ValueError('input format details required for device')
+        device_name = '' if input == 'device' else input[7:]
+        return SoundDeviceAudioInput(device_name, pcm_format)
+
+    # If there's no file: prefix, check if we can assume it is a file.
+    if pathlib.Path(input).is_file():
+        input = 'file:' + input
+
+    if input.startswith('file:'):
+        filename = input[5:]
+        if filename.endswith('.wav'):
+            if input_format != 'auto':
+                raise ValueError(".wav file only supported with 'auto' format")
+            return WaveAudioInput(filename)
+
+        if pcm_format is None:
+            raise ValueError('input format details required for raw PCM files')
+        return FileAudioInput(filename, pcm_format)
+
+    raise ValueError('input not supported')
+
+
+class AudioInput(abc.ABC):
+    """Audio input that produces PCM samples."""
+
+    @abc.abstractmethod
+    async def open(self) -> PcmFormat:
+        """Open the input."""
+
+    @abc.abstractmethod
+    def frames(self, frame_size: int) -> AsyncGenerator[bytes]:
+        """Generate one frame of PCM samples. Must not block."""
+
+    async def aclose(self) -> None:
+        """Close the input."""
+
+
+class ThreadedAudioInput(AudioInput):
+    """Base class for AudioInput implementation where reading samples may block."""
+
+    def __init__(self) -> None:
+        self._thread_pool = ThreadPoolExecutor(1)
+        self._pcm_samples: asyncio.Queue[bytes] = asyncio.Queue()
+
+    @abc.abstractmethod
+    def _read(self, frame_size: int) -> bytes:
+        pass
+
+    @abc.abstractmethod
+    def _open(self) -> PcmFormat:
+        pass
+
+    def _close(self) -> None:
+        pass
+
+    async def open(self) -> PcmFormat:
+        return await asyncio.get_running_loop().run_in_executor(
+            self._thread_pool, self._open
+        )
+
+    async def frames(self, frame_size: int) -> AsyncGenerator[bytes]:
+        while pcm_sample := await asyncio.get_running_loop().run_in_executor(
+            self._thread_pool, self._read, frame_size
+        ):
+            yield pcm_sample
+
+    async def aclose(self) -> None:
+        await asyncio.get_running_loop().run_in_executor(self._thread_pool, self._close)
+        self._thread_pool.shutdown()
+
+
+class WaveAudioInput(ThreadedAudioInput):
+    """Audio input that reads PCM samples from a .wav file."""
+
+    def __init__(self, filename: str) -> None:
+        super().__init__()
+        self._filename = filename
+        self._wav: wave.Wave_read | None = None
+        self._bytes_read = 0
+
+    def _open(self) -> PcmFormat:
+        self._wav = wave.open(self._filename, 'rb')
+        if self._wav.getsampwidth() != 2:
+            raise ValueError('sample width not supported')
+        return PcmFormat(
+            PcmFormat.Endianness.LITTLE,
+            PcmFormat.SampleType.INT16,
+            self._wav.getframerate(),
+            self._wav.getnchannels(),
+        )
+
+    def _read(self, frame_size: int) -> bytes:
+        if not self._wav:
+            return b''
+
+        pcm_samples = self._wav.readframes(frame_size)
+        if not pcm_samples and self._bytes_read:
+            # Loop around.
+            self._wav.rewind()
+            self._bytes_read = 0
+            pcm_samples = self._wav.readframes(frame_size)
+
+        self._bytes_read += len(pcm_samples)
+        return pcm_samples
+
+    def _close(self) -> None:
+        if self._wav:
+            self._wav.close()
+
+
+class StreamAudioInput(ThreadedAudioInput):
+    """AudioInput where samples are read from a raw PCM stream that may block."""
+
+    def __init__(self, stream: BinaryIO, pcm_format: PcmFormat) -> None:
+        super().__init__()
+        self._stream = stream
+        self._pcm_format = pcm_format
+
+    def _open(self) -> PcmFormat:
+        return self._pcm_format
+
+    def _read(self, frame_size: int) -> bytes:
+        return self._stream.read(
+            frame_size * self._pcm_format.channels * self._pcm_format.bytes_per_sample
+        )
+
+
+class FileAudioInput(StreamAudioInput):
+    """AudioInput where PCM samples are read from a raw PCM file."""
+
+    def __init__(self, filename: str, pcm_format: PcmFormat) -> None:
+        self._stream = open(filename, "rb")
+        super().__init__(self._stream, pcm_format)
+
+    def _close(self) -> None:
+        self._stream.close()
+
+
+class SoundDeviceAudioInput(ThreadedAudioInput):
+    def __init__(self, device_name: str, pcm_format: PcmFormat) -> None:
+        super().__init__()
+        self._device = int(device_name) if device_name else None
+        self._pcm_format = pcm_format
+        self._stream: sounddevice.RawInputStream | None = None
+
+    def _open(self) -> PcmFormat:
+        import sounddevice  # pylint: disable=import-error
+
+        self._stream = sounddevice.RawInputStream(
+            samplerate=self._pcm_format.sample_rate,
+            device=self._device,
+            channels=self._pcm_format.channels,
+            dtype='int16',
+        )
+        self._stream.start()
+
+        return PcmFormat(
+            PcmFormat.Endianness.LITTLE,
+            PcmFormat.SampleType.INT16,
+            self._pcm_format.sample_rate,
+            2,
+        )
+
+    def _read(self, frame_size: int) -> bytes:
+        if not self._stream:
+            return b''
+        pcm_buffer, overflowed = self._stream.read(frame_size)
+        if overflowed:
+            logger.warning("input overflow")
+
+        # Convert the buffer to stereo if needed
+        if self._pcm_format.channels == 1:
+            stereo_buffer = bytearray()
+            for i in range(frame_size):
+                sample = pcm_buffer[i * 2 : i * 2 + 2]
+                stereo_buffer += sample + sample
+            return stereo_buffer
+
+        return bytes(pcm_buffer)
+
+    def _close(self):
+        self._stream.stop()
+        self._stream = None

bumble/device.py

@@ -17,6 +17,7 @@
 # -----------------------------------------------------------------------------
 from __future__ import annotations
 import asyncio
+import collections
 from collections.abc import Iterable, Sequence
 from contextlib import (
     asynccontextmanager,
@@ -36,6 +37,7 @@ from typing import (
     Any,
     Callable,
     ClassVar,
+    Deque,
     Dict,
     Optional,
     Type,
@@ -1506,6 +1508,49 @@ class BisLink(_IsoLink):
         self.device = self.big.device
 
 
+# -----------------------------------------------------------------------------
+class IsoPacketStream:
+    """Async stream that can write SDUs to a CIS or BIS, with a maximum queue size."""
+
+    iso_link: _IsoLink
+    data_packet_queue: DataPacketQueue
+
+    def __init__(self, iso_link: _IsoLink, max_queue_size: int) -> None:
+        if iso_link.data_packet_queue is None:
+            raise ValueError('link has no data packet queue')
+
+        self.iso_link = iso_link
+        self.data_packet_queue = iso_link.data_packet_queue
+        self.data_packet_queue.on('flow', self._on_flow)
+        self._thresholds: Deque[int] = collections.deque()
+        self._semaphore = asyncio.Semaphore(max_queue_size)
+
+    def _on_flow(self) -> None:
+        # Release the semaphore once for each completed packet.
+        while (
+            self._thresholds and self.data_packet_queue.completed >= self._thresholds[0]
+        ):
+            self._thresholds.popleft()
+            self._semaphore.release()
+
+    async def write(self, sdu: bytes) -> None:
+        """
+        Write an SDU to the queue.
+
+        This method blocks until there are fewer than max_queue_size packets queued
+        but not yet completed.
+        """
+
+        # Wait until there's space in the queue.
+        await self._semaphore.acquire()
+
+        # Queue the packet.
+        self.iso_link.write(sdu)
+
+        # Remember the position of the packet so we can know when it is completed.
+        self._thresholds.append(self.data_packet_queue.queued)
+
+
 # -----------------------------------------------------------------------------
 class Connection(CompositeEventEmitter):
     device: Device

bumble/gatt.py

@@ -42,7 +42,7 @@ from typing import (
 )
 
 from bumble.colors import color
-from bumble.core import BaseBumbleError, UUID
+from bumble.core import BaseBumbleError, InvalidOperationError, UUID
 from bumble.att import Attribute, AttributeValue
 from bumble.utils import ByteSerializable
 
@@ -314,6 +314,7 @@ GATT_CENTRAL_ADDRESS_RESOLUTION__CHARACTERISTIC                = UUID.from_16_bi
 GATT_CLIENT_SUPPORTED_FEATURES_CHARACTERISTIC                  = UUID.from_16_bits(0x2B29, 'Client Supported Features')
 GATT_DATABASE_HASH_CHARACTERISTIC                              = UUID.from_16_bits(0x2B2A, 'Database Hash')
 GATT_SERVER_SUPPORTED_FEATURES_CHARACTERISTIC                  = UUID.from_16_bits(0x2B3A, 'Server Supported Features')
+GATT_LE_GATT_SECURITY_LEVELS_CHARACTERISTIC                    = UUID.from_16_bits(0x2BF5, 'E GATT Security Levels')
 
 # fmt: on
 # pylint: enable=line-too-long
@@ -322,8 +323,6 @@ GATT_SERVER_SUPPORTED_FEATURES_CHARACTERISTIC                  = UUID.from_16_bi
 # -----------------------------------------------------------------------------
 # Utils
 # -----------------------------------------------------------------------------
-
-
 def show_services(services: Iterable[Service]) -> None:
     for service in services:
         print(color(str(service), 'cyan'))
@@ -679,10 +678,14 @@ class DelegatedCharacteristicAdapter(CharacteristicAdapter):
         self.decode = decode
 
     def encode_value(self, value):
-        return self.encode(value) if self.encode else value
+        if self.encode is None:
+            raise InvalidOperationError('delegated adapter does not have an encoder')
+        return self.encode(value)
 
     def decode_value(self, value):
-        return self.decode(value) if self.decode else value
+        if self.decode is None:
+            raise InvalidOperationError('delegate adapter does not have a decoder')
+        return self.decode(value)
 
 
 # -----------------------------------------------------------------------------

bumble/gatt_client.py

@@ -78,6 +78,7 @@ from .gatt import (
     GATT_INCLUDE_ATTRIBUTE_TYPE,
     Characteristic,
     ClientCharacteristicConfigurationBits,
+    InvalidServiceError,
     TemplateService,
 )
 
@@ -162,12 +163,23 @@ class ServiceProxy(AttributeProxy):
         self.uuid = uuid
         self.characteristics = []
 
-    async def discover_characteristics(self, uuids=()):
+    async def discover_characteristics(self, uuids=()) -> list[CharacteristicProxy]:
         return await self.client.discover_characteristics(uuids, self)
 
-    def get_characteristics_by_uuid(self, uuid):
+    def get_characteristics_by_uuid(self, uuid: UUID) -> list[CharacteristicProxy]:
+        """Get all the characteristics with a specified UUID."""
         return self.client.get_characteristics_by_uuid(uuid, self)
 
+    def get_required_characteristic_by_uuid(self, uuid: UUID) -> CharacteristicProxy:
+        """
+        Get the first characteristic with a specified UUID.
+
+        If no characteristic with that UUID is found, an InvalidServiceError is raised.
+        """
+        if not (characteristics := self.get_characteristics_by_uuid(uuid)):
+            raise InvalidServiceError(f'{uuid} characteristic not found')
+        return characteristics[0]
+
     def __str__(self) -> str:
         return f'Service(handle=0x{self.handle:04X}, uuid={self.uuid})'
 

bumble/profiles/aics.py

@@ -451,54 +451,35 @@ class AICSServiceProxy(ProfileServiceProxy):
     def __init__(self, service_proxy: ServiceProxy) -> None:
         self.service_proxy = service_proxy
 
-        if not (
-            characteristics := service_proxy.get_characteristics_by_uuid(
-                GATT_AUDIO_INPUT_STATE_CHARACTERISTIC
-            )
-        ):
-            raise gatt.InvalidServiceError("Audio Input State Characteristic not found")
         self.audio_input_state = SerializableCharacteristicAdapter(
-            characteristics[0], AudioInputState
+            service_proxy.get_required_characteristic_by_uuid(
+                GATT_AUDIO_INPUT_STATE_CHARACTERISTIC
+            ),
+            AudioInputState,
         )
 
-        if not (
-            characteristics := service_proxy.get_characteristics_by_uuid(
-                GATT_GAIN_SETTINGS_ATTRIBUTE_CHARACTERISTIC
-            )
-        ):
-            raise gatt.InvalidServiceError(
-                "Gain Settings Attribute Characteristic not found"
-            )
         self.gain_settings_properties = SerializableCharacteristicAdapter(
-            characteristics[0], GainSettingsProperties
+            service_proxy.get_required_characteristic_by_uuid(
+                GATT_GAIN_SETTINGS_ATTRIBUTE_CHARACTERISTIC
+            ),
+            GainSettingsProperties,
         )
 
-        if not (
+        self.audio_input_status = PackedCharacteristicAdapter(
-            characteristics := service_proxy.get_characteristics_by_uuid(
+            service_proxy.get_required_characteristic_by_uuid(
                 GATT_AUDIO_INPUT_STATUS_CHARACTERISTIC
-            )
+            ),
-        ):
+            'B',
-            raise gatt.InvalidServiceError(
+        )
-                "Audio Input Status Characteristic not found"
-            )
-        self.audio_input_status = PackedCharacteristicAdapter(characteristics[0], 'B')
 
-        if not (
+        self.audio_input_control_point = (
-            characteristics := service_proxy.get_characteristics_by_uuid(
+            service_proxy.get_required_characteristic_by_uuid(
                 GATT_AUDIO_INPUT_CONTROL_POINT_CHARACTERISTIC
             )
-        ):
+        )
-            raise gatt.InvalidServiceError(
-                "Audio Input Control Point Characteristic not found"
-            )
-        self.audio_input_control_point = characteristics[0]
 
-        if not (
+        self.audio_input_description = UTF8CharacteristicAdapter(
-            characteristics := service_proxy.get_characteristics_by_uuid(
+            service_proxy.get_required_characteristic_by_uuid(
                 GATT_AUDIO_INPUT_DESCRIPTION_CHARACTERISTIC
             )
-        ):
+        )
-            raise gatt.InvalidServiceError(
-                "Audio Input Description Characteristic not found"
-            )
-        self.audio_input_description = UTF8CharacteristicAdapter(characteristics[0])

bumble/profiles/asha.py

@@ -288,8 +288,8 @@ class AshaServiceProxy(gatt_client.ProfileServiceProxy):
                 'psm_characteristic',
             ),
         ):
-            if not (
+            setattr(
-                characteristics := self.service_proxy.get_characteristics_by_uuid(uuid)
+                self,
-            ):
+                attribute_name,
-                raise gatt.InvalidServiceError(f"Missing {uuid} Characteristic")
+                self.service_proxy.get_required_characteristic_by_uuid(uuid),
-            setattr(self, attribute_name, characteristics[0])
+            )

bumble/profiles/bass.py

@@ -354,34 +354,25 @@ class BroadcastAudioScanServiceProxy(gatt_client.ProfileServiceProxy):
     SERVICE_CLASS = BroadcastAudioScanService
 
     broadcast_audio_scan_control_point: gatt_client.CharacteristicProxy
-    broadcast_receive_states: List[gatt.SerializableCharacteristicAdapter]
+    broadcast_receive_states: List[gatt.DelegatedCharacteristicAdapter]
 
     def __init__(self, service_proxy: gatt_client.ServiceProxy):
         self.service_proxy = service_proxy
 
-        if not (
+        self.broadcast_audio_scan_control_point = (
-            characteristics := service_proxy.get_characteristics_by_uuid(
+            service_proxy.get_required_characteristic_by_uuid(
                 gatt.GATT_BROADCAST_AUDIO_SCAN_CONTROL_POINT_CHARACTERISTIC
             )
-        ):
+        )
-            raise gatt.InvalidServiceError(
-                "Broadcast Audio Scan Control Point characteristic not found"
-            )
-        self.broadcast_audio_scan_control_point = characteristics[0]
 
-        if not (
+        self.broadcast_receive_states = [
-            characteristics := service_proxy.get_characteristics_by_uuid(
+            gatt.DelegatedCharacteristicAdapter(
+                characteristic,
+                decode=lambda x: BroadcastReceiveState.from_bytes(x) if x else None,
+            )
+            for characteristic in service_proxy.get_characteristics_by_uuid(
                 gatt.GATT_BROADCAST_RECEIVE_STATE_CHARACTERISTIC
             )
-        ):
-            raise gatt.InvalidServiceError(
-                "Broadcast Receive State characteristic not found"
-            )
-        self.broadcast_receive_states = [
-            gatt.SerializableCharacteristicAdapter(
-                characteristic, BroadcastReceiveState
-            )
-            for characteristic in characteristics
         ]
 
     async def send_control_point_operation(

bumble/profiles/gmap.py

@@ -30,7 +30,6 @@ from bumble.gatt import (
     GATT_UGT_FEATURES_CHARACTERISTIC,
     GATT_BGS_FEATURES_CHARACTERISTIC,
     GATT_BGR_FEATURES_CHARACTERISTIC,
-    InvalidServiceError,
 )
 from bumble.gatt_client import ProfileServiceProxy, ServiceProxy
 from enum import IntFlag
@@ -154,14 +153,10 @@ class GamingAudioServiceProxy(ProfileServiceProxy):
     def __init__(self, service_proxy: ServiceProxy) -> None:
         self.service_proxy = service_proxy
 
-        if not (
-            characteristics := service_proxy.get_characteristics_by_uuid(
-                GATT_GMAP_ROLE_CHARACTERISTIC
-            )
-        ):
-            raise InvalidServiceError("GMAP Role Characteristic not found")
         self.gmap_role = DelegatedCharacteristicAdapter(
-            characteristic=characteristics[0],
+            service_proxy.get_required_characteristic_by_uuid(
+                GATT_GMAP_ROLE_CHARACTERISTIC
+            ),
             decode=lambda value: GmapRole(value[0]),
         )
 

bumble/profiles/le_audio.py

@@ -17,23 +17,35 @@
 # -----------------------------------------------------------------------------
 from __future__ import annotations
 import dataclasses
+import enum
 import struct
-from typing import List, Type
+from typing import Any, List, Type
 from typing_extensions import Self
 
+from bumble.profiles import bap
 from bumble import utils
 
 
 # -----------------------------------------------------------------------------
 # Classes
 # -----------------------------------------------------------------------------
+class AudioActiveState(utils.OpenIntEnum):
+    NO_AUDIO_DATA_TRANSMITTED = 0x00
+    AUDIO_DATA_TRANSMITTED = 0x01
+
+
+class AssistedListeningStream(utils.OpenIntEnum):
+    UNSPECIFIED_AUDIO_ENHANCEMENT = 0x00
+
+
 @dataclasses.dataclass
 class Metadata:
     '''Bluetooth Assigned Numbers, Section 6.12.6 - Metadata LTV structures.
 
-    As Metadata fields may extend, and Spec doesn't forbid duplication, we don't parse
+    As Metadata fields may extend, and the spec may not guarantee the uniqueness of
-    Metadata into a key-value style dataclass here. Rather, we encourage users to parse
+    tags, we don't automatically parse the Metadata data into specific classes.
-    again outside the lib.
+    Users of this class may decode the data by themselves, or use the Entry.decode
+    method.
     '''
 
     class Tag(utils.OpenIntEnum):
@@ -57,6 +69,44 @@ class Metadata:
         tag: Metadata.Tag
         data: bytes
 
+        def decode(self) -> Any:
+            """
+            Decode the data into an object, if possible.
+
+            If no specific object class exists to represent the data, the raw data
+            bytes are returned.
+            """
+
+            if self.tag in (
+                Metadata.Tag.PREFERRED_AUDIO_CONTEXTS,
+                Metadata.Tag.STREAMING_AUDIO_CONTEXTS,
+            ):
+                return bap.ContextType(struct.unpack("<H", self.data)[0])
+
+            if self.tag in (
+                Metadata.Tag.PROGRAM_INFO,
+                Metadata.Tag.PROGRAM_INFO_URI,
+                Metadata.Tag.BROADCAST_NAME,
+            ):
+                return self.data.decode("utf-8")
+
+            if self.tag == Metadata.Tag.LANGUAGE:
+                return self.data.decode("ascii")
+
+            if self.tag == Metadata.Tag.CCID_LIST:
+                return list(self.data)
+
+            if self.tag == Metadata.Tag.PARENTAL_RATING:
+                return self.data[0]
+
+            if self.tag == Metadata.Tag.AUDIO_ACTIVE_STATE:
+                return AudioActiveState(self.data[0])
+
+            if self.tag == Metadata.Tag.ASSISTED_LISTENING_STREAM:
+                return AssistedListeningStream(self.data[0])
+
+            return self.data
+
         @classmethod
         def from_bytes(cls: Type[Self], data: bytes) -> Self:
             return cls(tag=Metadata.Tag(data[0]), data=data[1:])
@@ -66,6 +116,29 @@ class Metadata:
 
     entries: List[Entry] = dataclasses.field(default_factory=list)
 
+    def pretty_print(self, indent: str) -> str:
+        """Convenience method to generate a string with one key-value pair per line."""
+
+        max_key_length = 0
+        keys = []
+        values = []
+        for entry in self.entries:
+            key = entry.tag.name
+            max_key_length = max(max_key_length, len(key))
+            keys.append(key)
+            decoded = entry.decode()
+            if isinstance(decoded, enum.Enum):
+                values.append(decoded.name)
+            elif isinstance(decoded, bytes):
+                values.append(decoded.hex())
+            else:
+                values.append(str(decoded))
+
+        return '\n'.join(
+            f'{indent}{key}: {" " * (max_key_length-len(key))}{value}'
+            for key, value in zip(keys, values)
+        )
+
     @classmethod
     def from_bytes(cls: Type[Self], data: bytes) -> Self:
         entries = []
@@ -81,3 +154,13 @@ class Metadata:
 
     def __bytes__(self) -> bytes:
         return b''.join([bytes(entry) for entry in self.entries])
+
+    def __str__(self) -> str:
+        entries_str = []
+        for entry in self.entries:
+            decoded = entry.decode()
+            entries_str.append(
+                f'{entry.tag.name}: '
+                f'{decoded.hex() if isinstance(decoded, bytes) else decoded!r}'
+            )
+        return f'Metadata(entries={", ".join(entry_str for entry_str in entries_str)})'

bumble/profiles/pacs.py

@@ -72,6 +72,19 @@ class PacRecord:
             metadata=metadata,
         )
 
+    @classmethod
+    def list_from_bytes(cls, data: bytes) -> list[PacRecord]:
+        """Parse a serialized list of records preceded by a one byte list length."""
+        record_count = data[0]
+        records = []
+        offset = 1
+        for _ in range(record_count):
+            record = PacRecord.from_bytes(data[offset:])
+            offset += len(bytes(record))
+            records.append(record)
+
+        return records
+
     def __bytes__(self) -> bytes:
         capabilities_bytes = bytes(self.codec_specific_capabilities)
         metadata_bytes = bytes(self.metadata)
@@ -172,39 +185,58 @@ class PublishedAudioCapabilitiesService(gatt.TemplateService):
 class PublishedAudioCapabilitiesServiceProxy(gatt_client.ProfileServiceProxy):
     SERVICE_CLASS = PublishedAudioCapabilitiesService
 
-    sink_pac: Optional[gatt_client.CharacteristicProxy] = None
+    sink_pac: Optional[gatt.DelegatedCharacteristicAdapter] = None
-    sink_audio_locations: Optional[gatt_client.CharacteristicProxy] = None
+    sink_audio_locations: Optional[gatt.DelegatedCharacteristicAdapter] = None
-    source_pac: Optional[gatt_client.CharacteristicProxy] = None
+    source_pac: Optional[gatt.DelegatedCharacteristicAdapter] = None
-    source_audio_locations: Optional[gatt_client.CharacteristicProxy] = None
+    source_audio_locations: Optional[gatt.DelegatedCharacteristicAdapter] = None
-    available_audio_contexts: gatt_client.CharacteristicProxy
+    available_audio_contexts: gatt.DelegatedCharacteristicAdapter
-    supported_audio_contexts: gatt_client.CharacteristicProxy
+    supported_audio_contexts: gatt.DelegatedCharacteristicAdapter
 
     def __init__(self, service_proxy: gatt_client.ServiceProxy):
         self.service_proxy = service_proxy
 
-        self.available_audio_contexts = service_proxy.get_characteristics_by_uuid(
+        self.available_audio_contexts = gatt.DelegatedCharacteristicAdapter(
-            gatt.GATT_AVAILABLE_AUDIO_CONTEXTS_CHARACTERISTIC
+            service_proxy.get_required_characteristic_by_uuid(
-        )[0]
+                gatt.GATT_AVAILABLE_AUDIO_CONTEXTS_CHARACTERISTIC
-        self.supported_audio_contexts = service_proxy.get_characteristics_by_uuid(
+            ),
-            gatt.GATT_SUPPORTED_AUDIO_CONTEXTS_CHARACTERISTIC
+            decode=lambda x: tuple(map(ContextType, struct.unpack('<HH', x))),
-        )[0]
+        )
+
+        self.supported_audio_contexts = gatt.DelegatedCharacteristicAdapter(
+            service_proxy.get_required_characteristic_by_uuid(
+                gatt.GATT_SUPPORTED_AUDIO_CONTEXTS_CHARACTERISTIC
+            ),
+            decode=lambda x: tuple(map(ContextType, struct.unpack('<HH', x))),
+        )
 
         if characteristics := service_proxy.get_characteristics_by_uuid(
             gatt.GATT_SINK_PAC_CHARACTERISTIC
         ):
-            self.sink_pac = characteristics[0]
+            self.sink_pac = gatt.DelegatedCharacteristicAdapter(
+                characteristics[0],
+                decode=PacRecord.list_from_bytes,
+            )
 
         if characteristics := service_proxy.get_characteristics_by_uuid(
             gatt.GATT_SOURCE_PAC_CHARACTERISTIC
         ):
-            self.source_pac = characteristics[0]
+            self.source_pac = gatt.DelegatedCharacteristicAdapter(
+                characteristics[0],
+                decode=PacRecord.list_from_bytes,
+            )
 
         if characteristics := service_proxy.get_characteristics_by_uuid(
             gatt.GATT_SINK_AUDIO_LOCATION_CHARACTERISTIC
         ):
-            self.sink_audio_locations = characteristics[0]
+            self.sink_audio_locations = gatt.DelegatedCharacteristicAdapter(
+                characteristics[0],
+                decode=lambda x: AudioLocation(struct.unpack('<I', x)[0]),
+            )
 
         if characteristics := service_proxy.get_characteristics_by_uuid(
             gatt.GATT_SOURCE_AUDIO_LOCATION_CHARACTERISTIC
         ):
-            self.source_audio_locations = characteristics[0]
+            self.source_audio_locations = gatt.DelegatedCharacteristicAdapter(
+                characteristics[0],
+                decode=lambda x: AudioLocation(struct.unpack('<I', x)[0]),
+            )

bumble/profiles/tmap.py

@@ -25,7 +25,6 @@ from bumble.gatt import (
     TemplateService,
     Characteristic,
     DelegatedCharacteristicAdapter,
-    InvalidServiceError,
     GATT_TELEPHONY_AND_MEDIA_AUDIO_SERVICE,
     GATT_TMAP_ROLE_CHARACTERISTIC,
 )
@@ -74,15 +73,10 @@ class TelephonyAndMediaAudioServiceProxy(ProfileServiceProxy):
     def __init__(self, service_proxy: ServiceProxy):
         self.service_proxy = service_proxy
 
-        if not (
-            characteristics := service_proxy.get_characteristics_by_uuid(
-                GATT_TMAP_ROLE_CHARACTERISTIC
-            )
-        ):
-            raise InvalidServiceError('TMAP Role characteristic not found')
-
         self.role = DelegatedCharacteristicAdapter(
-            characteristics[0],
+            service_proxy.get_required_characteristic_by_uuid(
+                GATT_TMAP_ROLE_CHARACTERISTIC
+            ),
             decode=lambda value: Role(
                 struct.unpack_from('<H', value, 0)[0],
             ),

bumble/profiles/vcs.py

@@ -1,4 +1,4 @@
-# Copyright 2021-2024 Google LLC
+# Copyright 2021-2025 Google LLC
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -17,14 +17,16 @@
 # Imports
 # -----------------------------------------------------------------------------
 from __future__ import annotations
+import dataclasses
 import enum
 
+from typing import Optional, Sequence
+
 from bumble import att
 from bumble import device
 from bumble import gatt
 from bumble import gatt_client
 
-from typing import Optional, Sequence
 
 # -----------------------------------------------------------------------------
 # Constants
@@ -67,6 +69,20 @@ class VolumeControlPointOpcode(enum.IntEnum):
     MUTE                        = 0x06
 
 
+@dataclasses.dataclass
+class VolumeState:
+    volume_setting: int
+    mute: int
+    change_counter: int
+
+    @classmethod
+    def from_bytes(cls, data: bytes) -> VolumeState:
+        return cls(data[0], data[1], data[2])
+
+    def __bytes__(self) -> bytes:
+        return bytes([self.volume_setting, self.mute, self.change_counter])
+
+
 # -----------------------------------------------------------------------------
 # Server
 # -----------------------------------------------------------------------------
@@ -126,16 +142,8 @@ class VolumeControlService(gatt.TemplateService):
             included_services=list(included_services),
         )
 
-    @property
-    def volume_state_bytes(self) -> bytes:
-        return bytes([self.volume_setting, self.muted, self.change_counter])
-
-    @volume_state_bytes.setter
-    def volume_state_bytes(self, new_value: bytes) -> None:
-        self.volume_setting, self.muted, self.change_counter = new_value
-
     def _on_read_volume_state(self, _connection: Optional[device.Connection]) -> bytes:
-        return self.volume_state_bytes
+        return bytes(VolumeState(self.volume_setting, self.muted, self.change_counter))
 
     def _on_write_volume_control_point(
         self, connection: Optional[device.Connection], value: bytes
@@ -153,14 +161,9 @@ class VolumeControlService(gatt.TemplateService):
             self.change_counter = (self.change_counter + 1) % 256
             connection.abort_on(
                 'disconnection',
-                connection.device.notify_subscribers(
+                connection.device.notify_subscribers(attribute=self.volume_state),
-                    attribute=self.volume_state,
-                    value=self.volume_state_bytes,
-                ),
-            )
-            self.emit(
-                'volume_state', self.volume_setting, self.muted, self.change_counter
             )
+            self.emit('volume_state_change')
 
     def _on_relative_volume_down(self) -> bool:
         old_volume = self.volume_setting
@@ -207,24 +210,26 @@ class VolumeControlServiceProxy(gatt_client.ProfileServiceProxy):
     SERVICE_CLASS = VolumeControlService
 
     volume_control_point: gatt_client.CharacteristicProxy
+    volume_state: gatt.SerializableCharacteristicAdapter
+    volume_flags: gatt.DelegatedCharacteristicAdapter
 
     def __init__(self, service_proxy: gatt_client.ServiceProxy) -> None:
         self.service_proxy = service_proxy
 
-        self.volume_state = gatt.PackedCharacteristicAdapter(
+        self.volume_state = gatt.SerializableCharacteristicAdapter(
-            service_proxy.get_characteristics_by_uuid(
+            service_proxy.get_required_characteristic_by_uuid(
                 gatt.GATT_VOLUME_STATE_CHARACTERISTIC
-            )[0],
+            ),
-            'BBB',
+            VolumeState,
         )
 
-        self.volume_control_point = service_proxy.get_characteristics_by_uuid(
+        self.volume_control_point = service_proxy.get_required_characteristic_by_uuid(
             gatt.GATT_VOLUME_CONTROL_POINT_CHARACTERISTIC
-        )[0]
+        )
-
+
-        self.volume_flags = gatt.PackedCharacteristicAdapter(
+        self.volume_flags = gatt.DelegatedCharacteristicAdapter(
-            service_proxy.get_characteristics_by_uuid(
+            service_proxy.get_required_characteristic_by_uuid(
-                gatt.GATT_VOLUME_FLAGS_CHARACTERISTIC
+                gatt.GATT_VOLUME_FLAGS_CHARACTERISTIC
-            )[0],
+            ),
-            'B',
+            decode=lambda data: VolumeFlags(data[0]),
         )

bumble/profiles/vocs.py

@@ -27,8 +27,8 @@ from bumble.gatt import (
     DelegatedCharacteristicAdapter,
     TemplateService,
     CharacteristicValue,
+    SerializableCharacteristicAdapter,
     UTF8CharacteristicAdapter,
-    InvalidServiceError,
     GATT_VOLUME_OFFSET_CONTROL_SERVICE,
     GATT_VOLUME_OFFSET_STATE_CHARACTERISTIC,
     GATT_AUDIO_LOCATION_CHARACTERISTIC,
@@ -82,9 +82,7 @@ class VolumeOffsetState:
 
     async def notify_subscribers_via_connection(self, connection: Connection) -> None:
         assert self.attribute_value is not None
-        await connection.device.notify_subscribers(
+        await connection.device.notify_subscribers(attribute=self.attribute_value)
-            attribute=self.attribute_value, value=bytes(self)
-        )
 
     def on_read(self, _connection: Optional[Connection]) -> bytes:
         return bytes(self)
@@ -111,9 +109,7 @@ class VocsAudioLocation:
         assert self.attribute_value
 
         self.audio_location = AudioLocation(int.from_bytes(value, 'little'))
-        await connection.device.notify_subscribers(
+        await connection.device.notify_subscribers(attribute=self.attribute_value)
-            attribute=self.attribute_value, value=value
-        )
 
 
 @dataclass
@@ -169,9 +165,7 @@ class AudioOutputDescription:
         assert self.attribute_value
 
         self.audio_output_description = value.decode('utf-8')
-        await connection.device.notify_subscribers(
+        await connection.device.notify_subscribers(attribute=self.attribute_value)
-            attribute=self.attribute_value, value=value
-        )
 
 
 # -----------------------------------------------------------------------------
@@ -203,37 +197,30 @@ class VolumeOffsetControlService(TemplateService):
             VolumeOffsetControlPoint(self.volume_offset_state)
         )
 
-        self.volume_offset_state_characteristic = DelegatedCharacteristicAdapter(
+        self.volume_offset_state_characteristic = Characteristic(
-            Characteristic(
+            uuid=GATT_VOLUME_OFFSET_STATE_CHARACTERISTIC,
-                uuid=GATT_VOLUME_OFFSET_STATE_CHARACTERISTIC,
+            properties=(
-                properties=(
+                Characteristic.Properties.READ | Characteristic.Properties.NOTIFY
-                    Characteristic.Properties.READ | Characteristic.Properties.NOTIFY
-                ),
-                permissions=Characteristic.Permissions.READ_REQUIRES_ENCRYPTION,
-                value=CharacteristicValue(read=self.volume_offset_state.on_read),
             ),
-            encode=lambda value: bytes(value),
+            permissions=Characteristic.Permissions.READ_REQUIRES_ENCRYPTION,
+            value=CharacteristicValue(read=self.volume_offset_state.on_read),
         )
 
-        self.audio_location_characteristic = DelegatedCharacteristicAdapter(
+        self.audio_location_characteristic = Characteristic(
-            Characteristic(
+            uuid=GATT_AUDIO_LOCATION_CHARACTERISTIC,
-                uuid=GATT_AUDIO_LOCATION_CHARACTERISTIC,
+            properties=(
-                properties=(
+                Characteristic.Properties.READ
-                    Characteristic.Properties.READ
+                | Characteristic.Properties.NOTIFY
-                    | Characteristic.Properties.NOTIFY
+                | Characteristic.Properties.WRITE_WITHOUT_RESPONSE
-                    | Characteristic.Properties.WRITE_WITHOUT_RESPONSE
+            ),
-                ),
+            permissions=(
-                permissions=(
+                Characteristic.Permissions.READ_REQUIRES_ENCRYPTION
-                    Characteristic.Permissions.READ_REQUIRES_ENCRYPTION
+                | Characteristic.Permissions.WRITE_REQUIRES_ENCRYPTION
-                    | Characteristic.Permissions.WRITE_REQUIRES_ENCRYPTION
+            ),
-                ),
+            value=CharacteristicValue(
-                value=CharacteristicValue(
+                read=self.audio_location.on_read,
-                    read=self.audio_location.on_read,
+                write=self.audio_location.on_write,
-                    write=self.audio_location.on_write,
-                ),
             ),
-            encode=lambda value: bytes(value),
-            decode=VocsAudioLocation.from_bytes,
         )
         self.audio_location.attribute_value = self.audio_location_characteristic.value
 
@@ -244,25 +231,22 @@ class VolumeOffsetControlService(TemplateService):
             value=CharacteristicValue(write=self.volume_offset_control_point.on_write),
         )
 
-        self.audio_output_description_characteristic = DelegatedCharacteristicAdapter(
+        self.audio_output_description_characteristic = Characteristic(
-            Characteristic(
+            uuid=GATT_AUDIO_OUTPUT_DESCRIPTION_CHARACTERISTIC,
-                uuid=GATT_AUDIO_OUTPUT_DESCRIPTION_CHARACTERISTIC,
+            properties=(
-                properties=(
+                Characteristic.Properties.READ
-                    Characteristic.Properties.READ
+                | Characteristic.Properties.NOTIFY
-                    | Characteristic.Properties.NOTIFY
+                | Characteristic.Properties.WRITE_WITHOUT_RESPONSE
-                    | Characteristic.Properties.WRITE_WITHOUT_RESPONSE
+            ),
-                ),
+            permissions=(
-                permissions=(
+                Characteristic.Permissions.READ_REQUIRES_ENCRYPTION
-                    Characteristic.Permissions.READ_REQUIRES_ENCRYPTION
+                | Characteristic.Permissions.WRITE_REQUIRES_ENCRYPTION
-                    | Characteristic.Permissions.WRITE_REQUIRES_ENCRYPTION
+            ),
-                ),
+            value=CharacteristicValue(
-                value=CharacteristicValue(
+                read=self.audio_output_description.on_read,
-                    read=self.audio_output_description.on_read,
+                write=self.audio_output_description.on_write,
-                    write=self.audio_output_description.on_write,
+            ),
-                ),
-            )
         )
-
         self.audio_output_description.attribute_value = (
             self.audio_output_description_characteristic.value
         )
@@ -287,44 +271,29 @@ class VolumeOffsetControlServiceProxy(ProfileServiceProxy):
     def __init__(self, service_proxy: ServiceProxy) -> None:
         self.service_proxy = service_proxy
 
-        if not (
+        self.volume_offset_state = SerializableCharacteristicAdapter(
-            characteristics := service_proxy.get_characteristics_by_uuid(
+            service_proxy.get_required_characteristic_by_uuid(
                 GATT_VOLUME_OFFSET_STATE_CHARACTERISTIC
-            )
+            ),
-        ):
+            VolumeOffsetState,
-            raise InvalidServiceError("Volume Offset State characteristic not found")
-        self.volume_offset_state = DelegatedCharacteristicAdapter(
-            characteristics[0], decode=VolumeOffsetState.from_bytes
         )
 
-        if not (
-            characteristics := service_proxy.get_characteristics_by_uuid(
-                GATT_AUDIO_LOCATION_CHARACTERISTIC
-            )
-        ):
-            raise InvalidServiceError("Audio Location characteristic not found")
         self.audio_location = DelegatedCharacteristicAdapter(
-            characteristics[0],
+            service_proxy.get_required_characteristic_by_uuid(
-            encode=lambda value: bytes(value),
+                GATT_AUDIO_LOCATION_CHARACTERISTIC
-            decode=VocsAudioLocation.from_bytes,
+            ),
+            encode=lambda value: bytes([int(value)]),
+            decode=lambda data: AudioLocation(data[0]),
         )
 
-        if not (
+        self.volume_offset_control_point = (
-            characteristics := service_proxy.get_characteristics_by_uuid(
+            service_proxy.get_required_characteristic_by_uuid(
                 GATT_VOLUME_OFFSET_CONTROL_POINT_CHARACTERISTIC
             )
-        ):
+        )
-            raise InvalidServiceError(
-                "Volume Offset Control Point characteristic not found"
-            )
-        self.volume_offset_control_point = characteristics[0]
 
-        if not (
+        self.audio_output_description = UTF8CharacteristicAdapter(
-            characteristics := service_proxy.get_characteristics_by_uuid(
+            service_proxy.get_required_characteristic_by_uuid(
                 GATT_AUDIO_OUTPUT_DESCRIPTION_CHARACTERISTIC
             )
-        ):
+        )
-            raise InvalidServiceError(
-                "Audio Output Description characteristic not found"
-            )
-        self.audio_output_description = UTF8CharacteristicAdapter(characteristics[0])

docs/mkdocs/mkdocs.yml

@@ -39,12 +39,14 @@ nav:
   - Drivers:
     - drivers/index.md
     - Realtek: drivers/realtek.md
+    - Intel: drivers/intel.md
   - API:
     - Guide: api/guide.md
     - Examples: api/examples.md
     - Reference: api/reference.md
   - Apps & Tools:
     - apps_and_tools/index.md
+    - Auracast: apps_and_tools/auracast.md
     - Console: apps_and_tools/console.md
     - Bench: apps_and_tools/bench.md
     - Speaker: apps_and_tools/speaker.md
@@ -108,8 +110,8 @@ markdown_extensions:
   - pymdownx.details
   - pymdownx.superfences
   - pymdownx.emoji:
-      emoji_index: !!python/name:materialx.emoji.twemoji
+      emoji_index: !!python/name:material.extensions.emoji.twemoji
-      emoji_generator: !!python/name:materialx.emoji.to_svg
+      emoji_generator: !!python/name:material.extensions.emoji.to_svg
   - pymdownx.tabbed:
       alternate_style: true
   - codehilite:

docs/mkdocs/src/apps_and_tools/index.md

@@ -4,12 +4,13 @@ APPS & TOOLS
 Included in the project are a few apps and tools, built on top of the core libraries.
 These include:
 
-  * [Console](console.md) - an interactive text-based console
+  * [Auracast](auracast.md) - Commands to broadcast, receive and/or control LE Audio.
-  * [Bench](bench.md) - Speed and Latency benchmarking between two devices (LE and Classic)
+  * [Console](console.md) - An interactive text-based console.
-  * [Pair](pair.md) - Pair/bond two devices (LE and Classic)
+  * [Bench](bench.md) - Speed and Latency benchmarking between two devices (LE and Classic).
-  * [Unbond](unbond.md) - Remove a previously established bond
+  * [Pair](pair.md) - Pair/bond two devices (LE and Classic).
-  * [HCI Bridge](hci_bridge.md) - a HCI transport bridge to connect two HCI transports and filter/snoop the HCI packets
+  * [Unbond](unbond.md) - Remove a previously established bond.
-  * [Golden Gate Bridge](gg_bridge.md) - a bridge between GATT and UDP to use with the Golden Gate "stack tool"
+  * [HCI Bridge](hci_bridge.md) - An HCI transport bridge to connect two HCI transports and filter/snoop the HCI packets.
-  * [Show](show.md) - Parse a file with HCI packets and print the details of each packet in a human readable form
+  * [Golden Gate Bridge](gg_bridge.md) - Bridge between GATT and UDP to use with the Golden Gate "stack tool".
+  * [Show](show.md) - Parse a file with HCI packets and print the details of each packet in a human readable form.
   * [Speaker](speaker.md) - Virtual Bluetooth speaker, with a command line and browser-based UI.
   * [Link Relay](link_relay.md) - WebSocket relay for virtual RemoteLink instances to communicate with each other.

docs/mkdocs/src/getting_started.md

@@ -9,9 +9,9 @@ for your platform.
 Throughout the documentation, when shell commands are shown, it is assumed that you can
 invoke Python as
 ```
-$ python
+$ python3
 ```
-If invoking python is different on your platform (it may be `python3` for example, or just `py` or `py.exe`),
+If invoking python is different on your platform (it may be `python` for example, or just `py` or `py.exe`),
 adjust accordingly.
 
 You may be simply using Bumble as a module for your own application or as a dependency to your own
@@ -30,12 +30,18 @@ manager, or from source.
     python environment, or in a virtual environment, such as a `venv`, `pyenv` or `conda` environment.
     See the [Python Environments page](development/python_environments.md) page for details.
 
+### Install from PyPI
+
+```
+$ python3 -m pip install bumble
+```
+
 ### Install From Source
 
 Install with `pip`. Run in a command shell in the directory where you downloaded the source
 distribution
 ```
-$ python -m pip install -e .
+$ python3 -m pip install -e .
 ```
 
 ### Install from GitHub
@@ -44,21 +50,21 @@ You can install directly from GitHub without first downloading the repo.
 
 Install the latest commit from the main branch with `pip`:
 ```
-$ python -m pip install git+https://github.com/google/bumble.git
+$ python3 -m pip install git+https://github.com/google/bumble.git
 ```
 
 You can specify a specific tag.
 
 Install tag `v0.0.1` with `pip`:
 ```
-$ python -m pip install git+https://github.com/google/bumble.git@v0.0.1
+$ python3 -m pip install git+https://github.com/google/bumble.git@v0.0.1
 ```
 
 You can also specify a specific commit.
 
 Install commit `27c0551` with `pip`:
 ```
-$ python -m pip install git+https://github.com/google/bumble.git@27c0551
+$ python3 -m pip install git+https://github.com/google/bumble.git@27c0551
 ```
 
 # Working On The Bumble Code
@@ -78,21 +84,21 @@ directory of the project.
 
 ```bash
 $ export PYTHONPATH=.
-$ python apps/console.py serial:/dev/tty.usbmodem0006839912171
+$ python3 apps/console.py serial:/dev/tty.usbmodem0006839912171
 ```
 
 or running an example, with the working directory set to the `examples` subdirectory
 ```bash
 $ cd examples
 $ export PYTHONPATH=..
-$ python run_scanner.py usb:0
+$ python3 run_scanner.py usb:0
 ```
 
 Or course, `export PYTHONPATH` only needs to be invoked once, not before each app/script execution.
 
 Setting `PYTHONPATH` locally with each command would look something like:
 ```
-$ PYTHONPATH=. python examples/run_advertiser.py examples/device1.json serial:/dev/tty.usbmodem0006839912171
+$ PYTHONPATH=. python3 examples/run_advertiser.py examples/device1.json serial:/dev/tty.usbmodem0006839912171
 ```
 
 # Where To Go Next

docs/mkdocs/src/platforms/android.md

@@ -35,11 +35,11 @@ the command line.
     visit [this Android Studio user guide page](https://developer.android.com/studio/run/emulator-commandline)
 
 The `-packet-streamer-endpoint <endpoint>` command line option may be used to enable
-Bluetooth emulation and tell the emulator which virtual controller to connect to. 
+Bluetooth emulation and tell the emulator which virtual controller to connect to.
 
 ## Connecting to Netsim
 
-If the emulator doesn't have Bluetooth emulation enabled by default, use the 
+If the emulator doesn't have Bluetooth emulation enabled by default, use the
 `-packet-streamer-endpoint default` option to tell it to connect to Netsim.
 If Netsim is not running, the emulator will start it automatically.
 
@@ -60,17 +60,17 @@ the Bumble `android-netsim` transport in `host` mode (the default).
 
 !!! example "Run the example GATT server connected to the emulator via Netsim"
     ``` shell
-    $ python run_gatt_server.py device1.json android-netsim
+    $ python3 run_gatt_server.py device1.json android-netsim
     ```
 
 By default, the Bumble `android-netsim` transport will try to automatically discover
 the port number on which the netsim process is exposing its gRPC server interface. If
-that discovery process fails, or if you want to specify the interface manually, you 
+that discovery process fails, or if you want to specify the interface manually, you
 can pass a `hostname` and `port` as parameters to the transport, as: `android-netsim:<host>:<port>`.
 
 !!! example "Run the example GATT server connected to the emulator via Netsim on a localhost, port 8877"
     ``` shell
-    $ python run_gatt_server.py device1.json android-netsim:localhost:8877
+    $ python3 run_gatt_server.py device1.json android-netsim:localhost:8877
     ```
 
 ### Multiple Instances
@@ -84,7 +84,7 @@ For example: `android-netsim:localhost:8877,name=bumble1`
 This is an advanced use case, which may not be officially supported, but should work in recent
 versions of the emulator.
 
-The first step is to run the Bumble HCI bridge, specifying netsim as the "host" end of the 
+The first step is to run the Bumble HCI bridge, specifying netsim as the "host" end of the
 bridge, and another controller (typically a USB Bluetooth dongle, but any other supported
 transport can work as well) as the "controller" end of the bridge.
 

examples/run_gatt_with_adapters.py

@@ -25,7 +25,7 @@ import struct
 import sys
 from typing import Any, List, Union
 
-from bumble.device import Connection, Device, Peer
+from bumble.device import Device, Peer
 from bumble import transport
 from bumble import gatt
 from bumble import hci
@@ -82,19 +82,19 @@ async def client(device: Device, address: hci.Address) -> None:
     for index in range(1, 9):
         characteristics.append(
             service.get_characteristics_by_uuid(
-                CHARACTERISTIC_UUID_BASE + f"{index:02X}"
+                core.UUID(CHARACTERISTIC_UUID_BASE + f"{index:02X}")
             )[0]
         )
 
     # Read all characteristics as raw bytes.
     for characteristic in characteristics:
         value = await characteristic.read_value()
-        print(f"### {characteristic} = {value} ({value.hex()})")
+        print(f"### {characteristic} = {value!r} ({value.hex()})")
 
     # Static characteristic with a bytes value.
     c1 = characteristics[0]
     c1_value = await c1.read_value()
-    print(f"@@@ C1 {c1} value = {c1_value} (type={type(c1_value)})")
+    print(f"@@@ C1 {c1} value = {c1_value!r} (type={type(c1_value)})")
     await c1.write_value("happy π day".encode("utf-8"))
 
     # Static characteristic with a string value.
@@ -136,7 +136,7 @@ async def client(device: Device, address: hci.Address) -> None:
     # Dynamic characteristic with a bytes value.
     c7 = characteristics[6]
     c7_value = await c7.read_value()
-    print(f"@@@ C7 {c7} value = {c7_value} (type={type(c7_value)})")
+    print(f"@@@ C7 {c7} value = {c7_value!r} (type={type(c7_value)})")
     await c7.write_value(bytes.fromhex("01020304"))
 
     # Dynamic characteristic with a string value.

examples/run_vcp_renderer.py

@@ -42,7 +42,7 @@ from bumble.profiles.bap import (
 from bumble.profiles.pacs import PacRecord, PublishedAudioCapabilitiesService
 from bumble.profiles.cap import CommonAudioServiceService
 from bumble.profiles.csip import CoordinatedSetIdentificationService, SirkType
-from bumble.profiles.vcp import VolumeControlService
+from bumble.profiles.vcs import VolumeControlService
 
 from bumble.transport import open_transport_or_link
 
@@ -117,13 +117,17 @@ async def main() -> None:
 
         ws: Optional[websockets.WebSocketServerProtocol] = None
 
-        def on_volume_state(volume_setting: int, muted: int, change_counter: int):
+        def on_volume_state_change():
             if ws:
                 asyncio.create_task(
-                    ws.send(dumps_volume_state(volume_setting, muted, change_counter))
+                    ws.send(
+                        dumps_volume_state(
+                            vcs.volume_setting, vcs.muted, vcs.change_counter
+                        )
+                    )
                 )
 
-        vcs.on('volume_state', on_volume_state)
+        vcs.on('volume_state_change', on_volume_state_change)
 
         advertising_data = (
             bytes(
@@ -170,16 +174,10 @@ async def main() -> None:
             ws = websocket
             async for message in websocket:
                 volume_state = json.loads(message)
-                vcs.volume_state_bytes = bytes(
+                vcs.volume_setting = volume_state['volume_setting']
-                    [
+                vcs.muted = volume_state['muted']
-                        volume_state['volume_setting'],
+                vcs.change_counter = volume_state['change_counter']
-                        volume_state['muted'],
+                await device.notify_subscribers(vcs.volume_state)
-                        volume_state['change_counter'],
-                    ]
-                )
-                await device.notify_subscribers(
-                    vcs.volume_state, vcs.volume_state_bytes
-                )
             ws = None
 
         await websockets.serve(serve, 'localhost', 8989)

pyproject.toml

@@ -61,15 +61,17 @@ avatar = [
 ]
 pandora = ["bt-test-interfaces >= 0.0.6"]
 documentation = [
-    "mkdocs >= 1.4.0",
+    "mkdocs >= 1.6.0",
-    "mkdocs-material >= 8.5.6",
+    "mkdocs-material >= 9.6",
-    "mkdocstrings[python] >= 0.19.0",
+    "mkdocstrings[python] >= 0.27.0",
 ]
-lc3 = [
+auracast = [
-    "lc3 @ git+https://github.com/google/liblc3.git",
+    "lc3py ; python_version>='3.10' and platform_system=='Linux' and platform_machine=='x86_64'",
+    "sounddevice >= 0.5.1",
 ]
 
 [project.scripts]
+bumble-auracast = "bumble.apps.auracast:main"
 bumble-ble-rpa-tool = "bumble.apps.ble_rpa_tool:main"
 bumble-console = "bumble.apps.console:main"
 bumble-controller-info = "bumble.apps.controller_info:main"
@@ -190,6 +192,10 @@ ignore_missing_imports = true
 module = "serial_asyncio.*"
 ignore_missing_imports = true
 
+[[tool.mypy.overrides]]
+module = "sounddevice.*"
+ignore_missing_imports = true
+
 [[tool.mypy.overrides]]
 module = "usb.*"
 ignore_missing_imports = true

tests/aics_test.py

@@ -33,7 +33,7 @@ from bumble.profiles.aics import (
     AudioInputControlPointOpCode,
     ErrorCode,
 )
-from bumble.profiles.vcp import VolumeControlService, VolumeControlServiceProxy
+from bumble.profiles.vcs import VolumeControlService, VolumeControlServiceProxy
 
 from .test_utils import TwoDevices
 

tests/import_test.py

@@ -53,7 +53,7 @@ def test_import():
         le_audio,
         pacs,
         pbp,
-        vcp,
+        vcs,
     )
 
     assert att
@@ -87,7 +87,7 @@ def test_import():
     assert le_audio
     assert pacs
     assert pbp
-    assert vcp
+    assert vcs
 
 
 # -----------------------------------------------------------------------------

tests/vcp_test.py

@@ -20,7 +20,7 @@ import pytest_asyncio
 import logging
 
 from bumble import device
-from bumble.profiles import vcp
+from bumble.profiles import vcs
 from .test_utils import TwoDevices
 
 # -----------------------------------------------------------------------------
@@ -34,7 +34,7 @@ logger = logging.getLogger(__name__)
 async def vcp_client():
     devices = TwoDevices()
     devices[0].add_service(
-        vcp.VolumeControlService(volume_setting=32, muted=1, volume_flags=1)
+        vcs.VolumeControlService(volume_setting=32, muted=1, volume_flags=1)
     )
 
     await devices.setup_connection()
@@ -48,76 +48,76 @@ async def vcp_client():
 
     peer = device.Peer(devices.connections[1])
     vcp_client = await peer.discover_service_and_create_proxy(
-        vcp.VolumeControlServiceProxy
+        vcs.VolumeControlServiceProxy
     )
     yield vcp_client
 
 
 # -----------------------------------------------------------------------------
 @pytest.mark.asyncio
-async def test_init_service(vcp_client: vcp.VolumeControlServiceProxy):
+async def test_init_service(vcp_client: vcs.VolumeControlServiceProxy):
     assert (await vcp_client.volume_flags.read_value()) == 1
-    assert (await vcp_client.volume_state.read_value()) == (32, 1, 0)
+    assert (await vcp_client.volume_state.read_value()) == vcs.VolumeState(32, 1, 0)
 
 
 # -----------------------------------------------------------------------------
 @pytest.mark.asyncio
-async def test_relative_volume_down(vcp_client: vcp.VolumeControlServiceProxy):
+async def test_relative_volume_down(vcp_client: vcs.VolumeControlServiceProxy):
     await vcp_client.volume_control_point.write_value(
-        bytes([vcp.VolumeControlPointOpcode.RELATIVE_VOLUME_DOWN, 0])
+        bytes([vcs.VolumeControlPointOpcode.RELATIVE_VOLUME_DOWN, 0])
     )
-    assert (await vcp_client.volume_state.read_value()) == (16, 1, 1)
+    assert (await vcp_client.volume_state.read_value()) == vcs.VolumeState(16, 1, 1)
 
 
 # -----------------------------------------------------------------------------
 @pytest.mark.asyncio
-async def test_relative_volume_up(vcp_client: vcp.VolumeControlServiceProxy):
+async def test_relative_volume_up(vcp_client: vcs.VolumeControlServiceProxy):
     await vcp_client.volume_control_point.write_value(
-        bytes([vcp.VolumeControlPointOpcode.RELATIVE_VOLUME_UP, 0])
+        bytes([vcs.VolumeControlPointOpcode.RELATIVE_VOLUME_UP, 0])
     )
-    assert (await vcp_client.volume_state.read_value()) == (48, 1, 1)
+    assert (await vcp_client.volume_state.read_value()) == vcs.VolumeState(48, 1, 1)
 
 
 # -----------------------------------------------------------------------------
 @pytest.mark.asyncio
-async def test_unmute_relative_volume_down(vcp_client: vcp.VolumeControlServiceProxy):
+async def test_unmute_relative_volume_down(vcp_client: vcs.VolumeControlServiceProxy):
     await vcp_client.volume_control_point.write_value(
-        bytes([vcp.VolumeControlPointOpcode.UNMUTE_RELATIVE_VOLUME_DOWN, 0])
+        bytes([vcs.VolumeControlPointOpcode.UNMUTE_RELATIVE_VOLUME_DOWN, 0])
     )
-    assert (await vcp_client.volume_state.read_value()) == (16, 0, 1)
+    assert (await vcp_client.volume_state.read_value()) == vcs.VolumeState(16, 0, 1)
 
 
 # -----------------------------------------------------------------------------
 @pytest.mark.asyncio
-async def test_unmute_relative_volume_up(vcp_client: vcp.VolumeControlServiceProxy):
+async def test_unmute_relative_volume_up(vcp_client: vcs.VolumeControlServiceProxy):
     await vcp_client.volume_control_point.write_value(
-        bytes([vcp.VolumeControlPointOpcode.UNMUTE_RELATIVE_VOLUME_UP, 0])
+        bytes([vcs.VolumeControlPointOpcode.UNMUTE_RELATIVE_VOLUME_UP, 0])
     )
-    assert (await vcp_client.volume_state.read_value()) == (48, 0, 1)
+    assert (await vcp_client.volume_state.read_value()) == vcs.VolumeState(48, 0, 1)
 
 
 # -----------------------------------------------------------------------------
 @pytest.mark.asyncio
-async def test_set_absolute_volume(vcp_client: vcp.VolumeControlServiceProxy):
+async def test_set_absolute_volume(vcp_client: vcs.VolumeControlServiceProxy):
     await vcp_client.volume_control_point.write_value(
-        bytes([vcp.VolumeControlPointOpcode.SET_ABSOLUTE_VOLUME, 0, 255])
+        bytes([vcs.VolumeControlPointOpcode.SET_ABSOLUTE_VOLUME, 0, 255])
     )
-    assert (await vcp_client.volume_state.read_value()) == (255, 1, 1)
+    assert (await vcp_client.volume_state.read_value()) == vcs.VolumeState(255, 1, 1)
 
 
 # -----------------------------------------------------------------------------
 @pytest.mark.asyncio
-async def test_mute(vcp_client: vcp.VolumeControlServiceProxy):
+async def test_mute(vcp_client: vcs.VolumeControlServiceProxy):
     await vcp_client.volume_control_point.write_value(
-        bytes([vcp.VolumeControlPointOpcode.MUTE, 0])
+        bytes([vcs.VolumeControlPointOpcode.MUTE, 0])
     )
-    assert (await vcp_client.volume_state.read_value()) == (32, 1, 0)
+    assert (await vcp_client.volume_state.read_value()) == vcs.VolumeState(32, 1, 0)
 
 
 # -----------------------------------------------------------------------------
 @pytest.mark.asyncio
-async def test_unmute(vcp_client: vcp.VolumeControlServiceProxy):
+async def test_unmute(vcp_client: vcs.VolumeControlServiceProxy):
     await vcp_client.volume_control_point.write_value(
-        bytes([vcp.VolumeControlPointOpcode.UNMUTE, 0])
+        bytes([vcs.VolumeControlPointOpcode.UNMUTE, 0])
     )
-    assert (await vcp_client.volume_state.read_value()) == (32, 0, 1)
+    assert (await vcp_client.volume_state.read_value()) == vcs.VolumeState(32, 0, 1)

tests/vocs_test.py

@@ -32,9 +32,8 @@ from bumble.profiles.vocs import (
     SetVolumeOffsetOpCode,
     VolumeOffsetControlServiceProxy,
     VolumeOffsetState,
-    VocsAudioLocation,
 )
-from bumble.profiles.vcp import VolumeControlService, VolumeControlServiceProxy
+from bumble.profiles.vcs import VolumeControlService, VolumeControlServiceProxy
 from bumble.profiles.bap import AudioLocation
 
 from .test_utils import TwoDevices
@@ -81,9 +80,7 @@ async def test_init_service(vocs_client: VolumeOffsetControlServiceProxy):
         volume_offset=0,
         change_counter=0,
     )
-    assert await vocs_client.audio_location.read_value() == VocsAudioLocation(
+    assert await vocs_client.audio_location.read_value() == AudioLocation.NOT_ALLOWED
-        audio_location=AudioLocation.NOT_ALLOWED
-    )
     description = await vocs_client.audio_output_description.read_value()
     assert description == ''
 
@@ -162,11 +159,9 @@ async def test_set_volume_offset(vocs_client: VolumeOffsetControlServiceProxy):
 
 @pytest.mark.asyncio
 async def test_set_audio_channel_location(vocs_client: VolumeOffsetControlServiceProxy):
-    new_audio_location = VocsAudioLocation(audio_location=AudioLocation.FRONT_LEFT)
+    new_audio_location = AudioLocation.FRONT_LEFT
 
-    await vocs_client.audio_location.write_value(
+    await vocs_client.audio_location.write_value(new_audio_location)
-        struct.pack('<I', new_audio_location.audio_location)
-    )
 
     location = await vocs_client.audio_location.read_value()
     assert location == new_audio_location