Refactor ASHA service implementation and examples

bumble/decoder.py

@@ -12,6 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from typing import Union
+
 # -----------------------------------------------------------------------------
 # Constants
 # -----------------------------------------------------------------------------
@@ -149,28 +151,28 @@
 # -----------------------------------------------------------------------------
 # Classes
 # -----------------------------------------------------------------------------
-class G722Decoder(object):
+class G722Decoder:
     """G.722 decoder with bitrate 64kbit/s.
 
     For the Blocks in the sub-band decoders, please refer to the G.722
     specification for the required information. G722 specification:
     https://www.itu.int/rec/T-REC-G.722-201209-I
     """
 
-    def __init__(self):
+    def __init__(self) -> None:
         self._x = [0] * 24
         self._band = [Band(), Band()]
         # The initial value in BLOCK 3L
         self._band[0].det = 32
         # The initial value in BLOCK 3H
         self._band[1].det = 8
 
-    def decode_frame(self, encoded_data) -> bytearray:
+    def decode_frame(self, encoded_data: Union[bytes, bytearray]) -> bytearray:
         result_array = bytearray(len(encoded_data) * 4)
         self.g722_decode(result_array, encoded_data)
         return result_array
 
-    def g722_decode(self, result_array, encoded_data) -> int:
+    def g722_decode(self, result_array, encoded_data: Union[bytes, bytearray]) -> int:
         """Decode the data frame using g722 decoder."""
         result_length = 0
 
@@ -198,14 +200,16 @@ def g722_decode(self, result_array, encoded_data) -> int:
 
         return result_length
 
-    def update_decoded_result(self, xout, byte_length, byte_array) -> int:
+    def update_decoded_result(
+        self, xout: int, byte_length: int, byte_array: bytearray
+    ) -> int:
         result = (int)(xout >> 11)
         bytes_result = result.to_bytes(2, 'little', signed=True)
         byte_array[byte_length] = bytes_result[0]
         byte_array[byte_length + 1] = bytes_result[1]
         return byte_length + 2
 
-    def lower_sub_band_decoder(self, lower_bits) -> int:
+    def lower_sub_band_decoder(self, lower_bits: int) -> int:
         """Lower sub-band decoder for last six bits."""
 
         # Block 5L
@@ -258,7 +262,7 @@ def lower_sub_band_decoder(self, lower_bits) -> int:
 
         return rlow
 
-    def higher_sub_band_decoder(self, higher_bits) -> int:
+    def higher_sub_band_decoder(self, higher_bits: int) -> int:
         """Higher sub-band decoder for first two bits."""
 
         # Block 2H
@@ -306,14 +310,14 @@ def higher_sub_band_decoder(self, higher_bits) -> int:
 
 
 # -----------------------------------------------------------------------------
-class Band(object):
-    """Structure for G722 decode proccessing."""
+class Band:
+    """Structure for G722 decode processing."""
 
     s: int = 0
     nb: int = 0
     det: int = 0
 
-    def __init__(self):
+    def __init__(self) -> None:
         self._sp = 0
         self._sz = 0
         self._r = [0] * 3

bumble/profiles/asha.py

@@ -0,0 +1,295 @@
+# Copyright 2021-2022 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
+# -----------------------------------------------------------------------------
+import enum
+import struct
+import logging
+from typing import List, Optional, Callable, Union, Any
+
+from bumble import l2cap
+from bumble import utils
+from bumble import gatt
+from bumble import gatt_client
+from bumble.core import AdvertisingData
+from bumble.device import Device, Connection
+
+# -----------------------------------------------------------------------------
+# Logging
+# -----------------------------------------------------------------------------
+_logger = logging.getLogger(__name__)
+
+
+# -----------------------------------------------------------------------------
+# Constants
+# -----------------------------------------------------------------------------
+class DeviceCapabilities(enum.IntFlag):
+    IS_RIGHT = 0x01
+    IS_DUAL = 0x02
+    CSIS_SUPPORTED = 0x04
+
+
+class FeatureMap(enum.IntFlag):
+    LE_COC_AUDIO_OUTPUT_STREAMING_SUPPORTED = 0x01
+
+
+class AudioType(utils.OpenIntEnum):
+    UNKNOWN = 0x00
+    RINGTONE = 0x01
+    PHONE_CALL = 0x02
+    MEDIA = 0x03
+
+
+class OpCode(utils.OpenIntEnum):
+    START = 1
+    STOP = 2
+    STATUS = 3
+
+
+class Codec(utils.OpenIntEnum):
+    G_722_16KHZ = 1
+
+
+class SupportedCodecs(enum.IntFlag):
+    G_722_16KHZ = 1 << Codec.G_722_16KHZ
+
+
+class PeripheralStatus(utils.OpenIntEnum):
+    """Status update on the other peripheral."""
+
+    OTHER_PERIPHERAL_DISCONNECTED = 1
+    OTHER_PERIPHERAL_CONNECTED = 2
+    CONNECTION_PARAMETER_UPDATED = 3
+
+
+class AudioStatus(utils.OpenIntEnum):
+    """Status report field for the audio control point."""
+
+    OK = 0
+    UNKNOWN_COMMAND = -1
+    ILLEGAL_PARAMETERS = -2
+
+
+# -----------------------------------------------------------------------------
+class AshaService(gatt.TemplateService):
+    UUID = gatt.GATT_ASHA_SERVICE
+
+    audio_sink: Optional[Callable[[bytes], Any]]
+    active_codec: Optional[Codec] = None
+    audio_type: Optional[AudioType] = None
+    volume: Optional[int] = None
+    other_state: Optional[int] = None
+    connection: Optional[Connection] = None
+
+    def __init__(
+        self,
+        capability: int,
+        hisyncid: Union[List[int], bytes],
+        device: Device,
+        psm: int = 0,
+        audio_sink: Optional[Callable[[bytes], Any]] = None,
+        feature_map: int = FeatureMap.LE_COC_AUDIO_OUTPUT_STREAMING_SUPPORTED,
+        protocol_version: int = 0x01,
+        render_delay_milliseconds: int = 0,
+        supported_codecs: int = SupportedCodecs.G_722_16KHZ,
+    ) -> None:
+        if len(hisyncid) != 8:
+            _logger.warning('HiSyncId should have a length of 8, got %d', len(hisyncid))
+
+        self.hisyncid = bytes(hisyncid)
+        self.capability = capability
+        self.device = device
+        self.audio_out_data = b''
+        self.psm = psm  # a non-zero psm is mainly for testing purpose
+        self.audio_sink = audio_sink
+        self.protocol_version = protocol_version
+
+        self.read_only_properties_characteristic = gatt.Characteristic(
+            gatt.GATT_ASHA_READ_ONLY_PROPERTIES_CHARACTERISTIC,
+            gatt.Characteristic.Properties.READ,
+            gatt.Characteristic.READABLE,
+            struct.pack(
+                "<BB8sBH2sH",
+                protocol_version,
+                capability,
+                self.hisyncid,
+                feature_map,
+                render_delay_milliseconds,
+                b'\x00\x00',
+                supported_codecs,
+            ),
+        )
+
+        self.audio_control_point_characteristic = gatt.Characteristic(
+            gatt.GATT_ASHA_AUDIO_CONTROL_POINT_CHARACTERISTIC,
+            gatt.Characteristic.Properties.WRITE
+            | gatt.Characteristic.Properties.WRITE_WITHOUT_RESPONSE,
+            gatt.Characteristic.WRITEABLE,
+            gatt.CharacteristicValue(write=self._on_audio_control_point_write),
+        )
+        self.audio_status_characteristic = gatt.Characteristic(
+            gatt.GATT_ASHA_AUDIO_STATUS_CHARACTERISTIC,
+            gatt.Characteristic.Properties.READ | gatt.Characteristic.Properties.NOTIFY,
+            gatt.Characteristic.READABLE,
+            bytes([AudioStatus.OK]),
+        )
+        self.volume_characteristic = gatt.Characteristic(
+            gatt.GATT_ASHA_VOLUME_CHARACTERISTIC,
+            gatt.Characteristic.Properties.WRITE_WITHOUT_RESPONSE,
+            gatt.Characteristic.WRITEABLE,
+            gatt.CharacteristicValue(write=self._on_volume_write),
+        )
+
+        # let the server find a free PSM
+        self.psm = device.create_l2cap_server(
+            spec=l2cap.LeCreditBasedChannelSpec(psm=self.psm, max_credits=8),
+            handler=self._on_connection,
+        ).psm
+        self.le_psm_out_characteristic = gatt.Characteristic(
+            gatt.GATT_ASHA_LE_PSM_OUT_CHARACTERISTIC,
+            gatt.Characteristic.Properties.READ,
+            gatt.Characteristic.READABLE,
+            struct.pack('<H', self.psm),
+        )
+
+        characteristics = [
+            self.read_only_properties_characteristic,
+            self.audio_control_point_characteristic,
+            self.audio_status_characteristic,
+            self.volume_characteristic,
+            self.le_psm_out_characteristic,
+        ]
+
+        super().__init__(characteristics)
+
+    def get_advertising_data(self) -> bytes:
+        # Advertisement only uses 4 least significant bytes of the HiSyncId.
+        return bytes(
+            AdvertisingData(
+                [
+                    (
+                        AdvertisingData.SERVICE_DATA_16_BIT_UUID,
+                        bytes(gatt.GATT_ASHA_SERVICE)
+                        + bytes([self.protocol_version, self.capability])
+                        + self.hisyncid[:4],
+                    ),
+                ]
+            )
+        )
+
+    # Handler for audio control commands
+    async def _on_audio_control_point_write(
+        self, connection: Optional[Connection], value: bytes
+    ) -> None:
+        _logger.debug(f'--- AUDIO CONTROL POINT Write:{value.hex()}')
+        opcode = value[0]
+        if opcode == OpCode.START:
+            # Start
+            self.active_codec = Codec(value[1])
+            self.audio_type = AudioType(value[2])
+            self.volume = value[3]
+            self.other_state = value[4]
+            _logger.debug(
+                f'### START: codec={self.active_codec.name}, '
+                f'audio_type={self.audio_type.name}, '
+                f'volume={self.volume}, '
+                f'other_state={self.other_state}'
+            )
+            self.emit('started')
+        elif opcode == OpCode.STOP:
+            _logger.debug('### STOP')
+            self.active_codec = None
+            self.audio_type = None
+            self.volume = None
+            self.other_state = None
+            self.emit('stopped')
+        elif opcode == OpCode.STATUS:
+            _logger.debug('### STATUS: %s', PeripheralStatus(value[1]).name)
+
+        if self.connection is None and connection:
+            self.connection = connection
+
+            def on_disconnection(_reason) -> None:
+                self.connection = None
+                self.active_codec = None
+                self.audio_type = None
+                self.volume = None
+                self.other_state = None
+                self.emit('disconnected')
+
+            connection.once('disconnection', on_disconnection)
+
+        # OPCODE_STATUS does not need audio status point update
+        if opcode != OpCode.STATUS:
+            await self.device.notify_subscribers(
+                self.audio_status_characteristic, force=True
+            )
+
+    # Handler for volume control
+    def _on_volume_write(self, connection: Optional[Connection], value: bytes) -> None:
+        _logger.debug(f'--- VOLUME Write:{value[0]}')
+        self.volume = value[0]
+        self.emit('volume_changed')
+
+    # Register an L2CAP CoC server
+    def _on_connection(self, channel: l2cap.LeCreditBasedChannel) -> None:
+        def on_data(data: bytes) -> None:
+            if self.audio_sink:  # pylint: disable=not-callable
+                self.audio_sink(data)
+
+        channel.sink = on_data
+
+
+# -----------------------------------------------------------------------------
+class AshaServiceProxy(gatt_client.ProfileServiceProxy):
+    SERVICE_CLASS = AshaService
+    read_only_properties_characteristic: gatt_client.CharacteristicProxy
+    audio_control_point_characteristic: gatt_client.CharacteristicProxy
+    audio_status_point_characteristic: gatt_client.CharacteristicProxy
+    volume_characteristic: gatt_client.CharacteristicProxy
+    psm_characteristic: gatt_client.CharacteristicProxy
+
+    def __init__(self, service_proxy: gatt_client.ServiceProxy) -> None:
+        self.service_proxy = service_proxy
+
+        for uuid, attribute_name in (
+            (
+                gatt.GATT_ASHA_READ_ONLY_PROPERTIES_CHARACTERISTIC,
+                'read_only_properties_characteristic',
+            ),
+            (
+                gatt.GATT_ASHA_AUDIO_CONTROL_POINT_CHARACTERISTIC,
+                'audio_control_point_characteristic',
+            ),
+            (
+                gatt.GATT_ASHA_AUDIO_STATUS_CHARACTERISTIC,
+                'audio_status_point_characteristic',
+            ),
+            (
+                gatt.GATT_ASHA_VOLUME_CHARACTERISTIC,
+                'volume_characteristic',
+            ),
+            (
+                gatt.GATT_ASHA_LE_PSM_OUT_CHARACTERISTIC,
+                'psm_characteristic',
+            ),
+        ):
+            if not (
+                characteristics := self.service_proxy.get_characteristics_by_uuid(uuid)
+            ):
+                raise gatt.InvalidServiceError(f"Missing {uuid} Characteristic")
+            setattr(self, attribute_name, characteristics[0])