apps/lea_unicast/app.py

# Copyright 2021-2024 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 datetime
import functools
import json
import logging
import pathlib
import wave
import weakref
from importlib import resources

try:
    import lc3  # type: ignore  # pylint: disable=E0401
except ImportError as e:
    raise ImportError("Try `python -m pip install \".[lc3]\"`.") from e

import aiohttp.web
import click

import bumble
import bumble.logging
from bumble import data_types, utils
from bumble.colors import color
from bumble.core import AdvertisingData
from bumble.device import AdvertisingParameters, CisLink, Device, DeviceConfiguration
from bumble.hci import Address, CodecID, CodingFormat, HCI_IsoDataPacket
from bumble.profiles import ascs, bap, pacs
from bumble.transport import open_transport

# -----------------------------------------------------------------------------
# Logging
# -----------------------------------------------------------------------------
logger = logging.getLogger(__name__)

# -----------------------------------------------------------------------------
# Constants
# -----------------------------------------------------------------------------
DEFAULT_UI_PORT = 7654
DEFAULT_PCM_BYTES_PER_SAMPLE = 2


def _sink_pac_record() -> pacs.PacRecord:
    return pacs.PacRecord(
        coding_format=CodingFormat(CodecID.LC3),
        codec_specific_capabilities=bap.CodecSpecificCapabilities(
            supported_sampling_frequencies=(
                bap.SupportedSamplingFrequency.FREQ_8000
                | bap.SupportedSamplingFrequency.FREQ_16000
                | bap.SupportedSamplingFrequency.FREQ_24000
                | bap.SupportedSamplingFrequency.FREQ_32000
                | bap.SupportedSamplingFrequency.FREQ_48000
            ),
            supported_frame_durations=(
                bap.SupportedFrameDuration.DURATION_10000_US_SUPPORTED
            ),
            supported_audio_channel_count=[1, 2],
            min_octets_per_codec_frame=26,
            max_octets_per_codec_frame=240,
            supported_max_codec_frames_per_sdu=2,
        ),
    )


def _source_pac_record() -> pacs.PacRecord:
    return pacs.PacRecord(
        coding_format=CodingFormat(CodecID.LC3),
        codec_specific_capabilities=bap.CodecSpecificCapabilities(
            supported_sampling_frequencies=(
                bap.SupportedSamplingFrequency.FREQ_8000
                | bap.SupportedSamplingFrequency.FREQ_16000
                | bap.SupportedSamplingFrequency.FREQ_24000
                | bap.SupportedSamplingFrequency.FREQ_32000
                | bap.SupportedSamplingFrequency.FREQ_48000
            ),
            supported_frame_durations=(
                bap.SupportedFrameDuration.DURATION_10000_US_SUPPORTED
            ),
            supported_audio_channel_count=[1],
            min_octets_per_codec_frame=30,
            max_octets_per_codec_frame=100,
            supported_max_codec_frames_per_sdu=1,
        ),
    )


decoder: lc3.Decoder | None = None
encoding_config: bap.CodecSpecificConfiguration | None = None


async def lc3_source_task(
    filename: str,
    sdu_length: int,
    frame_duration_us: int,
    device: Device,
    cis_link: CisLink,
) -> None:
    logger.info(
        "lc3_source_task filename=%s, sdu_length=%d, frame_duration=%.1f",
        filename,
        sdu_length,
        frame_duration_us / 1000,
    )
    with wave.open(filename, 'rb') as wav:
        bits_per_sample = wav.getsampwidth() * 8

        encoder: lc3.Encoder | None = None

        while True:
            next_round = datetime.datetime.now() + datetime.timedelta(
                microseconds=frame_duration_us
            )
            if not encoder:
                if (
                    encoding_config
                    and (frame_duration := encoding_config.frame_duration)
                    and (sampling_frequency := encoding_config.sampling_frequency)
                    and (
                        audio_channel_allocation := encoding_config.audio_channel_allocation
                    )
                ):
                    logger.info("Use %s", encoding_config)
                    encoder = lc3.Encoder(
                        frame_duration_us=frame_duration.us,
                        sample_rate_hz=sampling_frequency.hz,
                        num_channels=audio_channel_allocation.channel_count,
                        input_sample_rate_hz=wav.getframerate(),
                    )
            else:
                sdu = encoder.encode(
                    pcm=wav.readframes(encoder.get_frame_samples()),
                    num_bytes=sdu_length,
                    bit_depth=bits_per_sample,
                )
                cis_link.write(sdu)

            sleep_time = next_round - datetime.datetime.now()
            await asyncio.sleep(sleep_time.total_seconds() * 0.9)


# -----------------------------------------------------------------------------
class UiServer:
    speaker: weakref.ReferenceType[Speaker]
    port: int

    def __init__(self, speaker: Speaker, port: int) -> None:
        self.speaker = weakref.ref(speaker)
        self.port = port
        self.channel_socket = None

    async def start_http(self) -> None:
        """Start the UI HTTP server."""

        app = aiohttp.web.Application()
        app.add_routes(
            [
                aiohttp.web.get('/', self.get_static),
                aiohttp.web.get('/index.html', self.get_static),
                aiohttp.web.get('/channel', self.get_channel),
            ]
        )

        runner = aiohttp.web.AppRunner(app)
        await runner.setup()
        site = aiohttp.web.TCPSite(runner, 'localhost', self.port)
        print('UI HTTP server at ' + color(f'http://127.0.0.1:{self.port}', 'green'))
        await site.start()

    async def get_static(self, request):
        path = request.path
        if path == '/':
            path = '/index.html'
        if path.endswith('.html'):
            content_type = 'text/html'
        elif path.endswith('.js'):
            content_type = 'text/javascript'
        elif path.endswith('.css'):
            content_type = 'text/css'
        elif path.endswith('.svg'):
            content_type = 'image/svg+xml'
        else:
            content_type = 'text/plain'
        text = (
            resources.files("bumble.apps.lea_unicast")
            .joinpath(pathlib.Path(path).relative_to('/'))
            .read_text(encoding="utf-8")
        )
        return aiohttp.web.Response(text=text, content_type=content_type)

    async def get_channel(self, request):
        ws = aiohttp.web.WebSocketResponse()
        await ws.prepare(request)

        # Process messages until the socket is closed.
        self.channel_socket = ws
        async for message in ws:
            if message.type == aiohttp.WSMsgType.TEXT:
                logger.debug(f'<<< received message: {message.data}')
                await self.on_message(message.data)
            elif message.type == aiohttp.WSMsgType.ERROR:
                logger.debug(
                    f'channel connection closed with exception {ws.exception()}'
                )

        self.channel_socket = None
        logger.debug('--- channel connection closed')

        return ws

    async def on_message(self, message_str: str):
        # Parse the message as JSON
        message = json.loads(message_str)

        # Dispatch the message
        message_type = message['type']
        message_params = message.get('params', {})
        handler = getattr(self, f'on_{message_type}_message')
        if handler:
            await handler(**message_params)

    async def on_hello_message(self):
        await self.send_message(
            'hello',
            bumble_version=bumble.__version__,
            codec=self.speaker().codec,
            streamState=self.speaker().stream_state.name,
        )
        if connection := self.speaker().connection:
            await self.send_message(
                'connection',
                peer_address=connection.peer_address.to_string(False),
                peer_name=connection.peer_name,
            )

    async def send_message(self, message_type: str, **kwargs) -> None:
        if self.channel_socket is None:
            return

        message = {'type': message_type, 'params': kwargs}
        await self.channel_socket.send_json(message)

    async def send_audio(self, data: bytes) -> None:
        if self.channel_socket is None:
            return

        try:
            await self.channel_socket.send_bytes(data)
        except Exception as error:
            logger.warning(f'exception while sending audio packet: {error}')


# -----------------------------------------------------------------------------
class Speaker:
    def __init__(
        self,
        device_config_path: str | None,
        ui_port: int,
        transport: str,
        lc3_input_file_path: str,
    ):
        self.device_config_path = device_config_path
        self.transport = transport
        self.lc3_input_file_path = lc3_input_file_path

        # Create an HTTP server for the UI
        self.ui_server = UiServer(speaker=self, port=ui_port)

    async def run(self) -> None:
        await self.ui_server.start_http()

        async with await open_transport(self.transport) as hci_transport:
            # Create a device
            if self.device_config_path:
                device_config = DeviceConfiguration.from_file(self.device_config_path)
            else:
                device_config = DeviceConfiguration(
                    name="Bumble LE Headphone",
                    class_of_device=0x244418,
                    keystore="JsonKeyStore",
                    advertising_interval_min=25,
                    advertising_interval_max=25,
                    address=Address('F1:F2:F3:F4:F5:F6'),
                    identity_address_type=Address.RANDOM_DEVICE_ADDRESS,
                    eatt_enabled=True,
                )

            device_config.le_enabled = True
            device_config.cis_enabled = True
            self.device = Device.from_config_with_hci(
                device_config, hci_transport.source, hci_transport.sink
            )

            self.device.add_service(
                pacs.PublishedAudioCapabilitiesService(
                    supported_source_context=bap.ContextType(0xFFFF),
                    available_source_context=bap.ContextType(0xFFFF),
                    supported_sink_context=bap.ContextType(0xFFFF),  # All context types
                    available_sink_context=bap.ContextType(0xFFFF),  # All context types
                    sink_audio_locations=(
                        bap.AudioLocation.FRONT_LEFT | bap.AudioLocation.FRONT_RIGHT
                    ),
                    sink_pac=[_sink_pac_record()],
                    source_audio_locations=bap.AudioLocation.FRONT_LEFT,
                    source_pac=[_source_pac_record()],
                )
            )

            ascs_service = ascs.AudioStreamControlService(
                self.device, sink_ase_id=[1], source_ase_id=[2]
            )
            self.device.add_service(ascs_service)

            advertising_data = bytes(
                AdvertisingData(
                    [
                        data_types.CompleteLocalName(device_config.name),
                        data_types.Flags(
                            AdvertisingData.Flags.LE_GENERAL_DISCOVERABLE_MODE
                            | AdvertisingData.Flags.BR_EDR_NOT_SUPPORTED
                        ),
                        data_types.IncompleteListOf16BitServiceUUIDs(
                            [pacs.PublishedAudioCapabilitiesService.UUID]
                        ),
                    ]
                )
            ) + bytes(bap.UnicastServerAdvertisingData())

            def on_pdu(pdu: HCI_IsoDataPacket, ase: ascs.AseStateMachine):
                codec_config = ase.codec_specific_configuration
                if (
                    not isinstance(codec_config, bap.CodecSpecificConfiguration)
                    or codec_config.frame_duration is None
                    or codec_config.audio_channel_allocation is None
                    or decoder is None
                    or not pdu.iso_sdu_fragment
                ):
                    return
                pcm = decoder.decode(
                    pdu.iso_sdu_fragment, bit_depth=DEFAULT_PCM_BYTES_PER_SAMPLE * 8
                )
                utils.cancel_on_event(
                    self.device, 'disconnection', self.ui_server.send_audio(pcm)
                )

            def on_ase_state_change(ase: ascs.AseStateMachine) -> None:
                codec_config = ase.codec_specific_configuration
                if ase.state == ascs.AseStateMachine.State.STREAMING:
                    if ase.role == ascs.AudioRole.SOURCE:
                        if (
                            not isinstance(codec_config, bap.CodecSpecificConfiguration)
                            or ase.cis_link is None
                            or codec_config.octets_per_codec_frame is None
                            or codec_config.frame_duration is None
                            or codec_config.codec_frames_per_sdu is None
                        ):
                            return
                        utils.cancel_on_event(
                            ase.cis_link,
                            'disconnection',
                            lc3_source_task(
                                filename=self.lc3_input_file_path,
                                sdu_length=(
                                    codec_config.codec_frames_per_sdu
                                    * codec_config.octets_per_codec_frame
                                ),
                                frame_duration_us=codec_config.frame_duration.us,
                                device=self.device,
                                cis_link=ase.cis_link,
                            ),
                        )
                    else:
                        if not ase.cis_link:
                            return
                        ase.cis_link.sink = functools.partial(on_pdu, ase=ase)
                elif ase.state == ascs.AseStateMachine.State.CODEC_CONFIGURED:
                    if (
                        not isinstance(codec_config, bap.CodecSpecificConfiguration)
                        or codec_config.sampling_frequency is None
                        or codec_config.frame_duration is None
                        or codec_config.audio_channel_allocation is None
                    ):
                        return
                    if ase.role == ascs.AudioRole.SOURCE:
                        global encoding_config
                        encoding_config = codec_config
                    else:
                        global decoder
                        decoder = lc3.Decoder(
                            frame_duration_us=codec_config.frame_duration.us,
                            sample_rate_hz=codec_config.sampling_frequency.hz,
                            num_channels=codec_config.audio_channel_allocation.channel_count,
                        )

            for ase in ascs_service.ase_state_machines.values():
                ase.on('state_change', functools.partial(on_ase_state_change, ase=ase))

            await self.device.power_on()
            await self.device.create_advertising_set(
                advertising_data=advertising_data,
                auto_restart=True,
                advertising_parameters=AdvertisingParameters(
                    primary_advertising_interval_min=100,
                    primary_advertising_interval_max=100,
                ),
            )

            await hci_transport.source.terminated


@click.command()
@click.option(
    '--ui-port',
    'ui_port',
    metavar='HTTP_PORT',
    default=DEFAULT_UI_PORT,
    show_default=True,
    help='HTTP port for the UI server',
)
@click.option('--device-config', metavar='FILENAME', help='Device configuration file')
@click.argument('transport')
@click.argument('lc3_file')
def speaker(ui_port: int, device_config: str, transport: str, lc3_file: str) -> None:
    """Run the speaker."""

    asyncio.run(Speaker(device_config, ui_port, transport, lc3_file).run())


# -----------------------------------------------------------------------------
def main():
    bumble.logging.setup_basic_logging()
    speaker()


# -----------------------------------------------------------------------------
if __name__ == "__main__":
    main()  # pylint: disable=no-value-for-parameter