HFP: Add example and fix AG errors

bumble/hfp.py

@@ -50,7 +50,7 @@ from bumble.core import (
     ProtocolError,
     BT_GENERIC_AUDIO_SERVICE,
     BT_HANDSFREE_SERVICE,
-    BT_HEADSET_AUDIO_GATEWAY_SERVICE,
+    BT_HANDSFREE_AUDIO_GATEWAY_SERVICE,
     BT_L2CAP_PROTOCOL_ID,
     BT_RFCOMM_PROTOCOL_ID,
 )
@@ -1156,7 +1156,7 @@ class AgProtocol(pyee.EventEmitter):
                 active_codec: AudioCodec
         hf_indicator: When HF update their indicators, notify the new state.
             Args:
-                hf_indicator: HfIndicator
+                hf_indicator: HfIndicatorState
         codec_connection_request: Emit when HF sends AT+BCC to request codec connection.
         answer: Emit when HF sends ATA to answer phone call.
         hang_up: Emit when HF sends AT+CHUP to hang up phone call.
@@ -1168,7 +1168,12 @@ class AgProtocol(pyee.EventEmitter):
             Args:
                 operation: CallHoldOperation
                 call_index: Optional[int]
-
+        speaker_volume: Emitted when AG update speaker volume autonomously.
+            Args:
+                volume: Int
+        microphone_volume: Emitted when AG update microphone volume autonomously.
+            Args:
+                volume: Int
     """
 
     supported_hf_features: int
@@ -1191,6 +1196,7 @@ class AgProtocol(pyee.EventEmitter):
     inband_ringtone_enabled: bool
     cme_error_enabled: bool
     cli_notification_enabled: bool
+    call_waiting_enabled: bool
     _remained_slc_setup_features: Set[HfFeature]
 
     def __init__(self, dlc: rfcomm.DLC, configuration: AgConfiguration) -> None:
@@ -1218,6 +1224,7 @@ class AgProtocol(pyee.EventEmitter):
         self.indicator_report_enabled = False
         self.cme_error_enabled = False
         self.cli_notification_enabled = False
+        self.call_waiting_enabled = False
 
         self.hf_indicators = collections.OrderedDict()
 
@@ -1465,7 +1472,12 @@ class AgProtocol(pyee.EventEmitter):
         display: Optional[bytes] = None,
         indicator: bytes = b'',
     ) -> None:
-        if int(mode) != 3 or keypad or display or int(indicator) not in (0, 1):
+        if (
+            int(mode) != 3
+            or (keypad and int(keypad))
+            or (display and int(display))
+            or int(indicator) not in (0, 1)
+        ):
             logger.error(
                 f'Unexpected values: mode={mode!r}, keypad={keypad!r}, '
                 f'display={display!r}, indicator={indicator!r}'
@@ -1479,6 +1491,10 @@ class AgProtocol(pyee.EventEmitter):
         self.cme_error_enabled = bool(int(enabled))
         self.send_ok()
 
+    def _on_ccwa(self, enabled: bytes) -> None:
+        self.call_waiting_enabled = bool(int(enabled))
+        self.send_ok()
+
     def _on_bind(self, *args) -> None:
         if not self.supports_ag_feature(AgFeature.HF_INDICATORS):
             self.send_error()
@@ -1578,6 +1594,15 @@ class AgProtocol(pyee.EventEmitter):
         if not self.supports_hf_feature(HfFeature.CLI_PRESENTATION_CAPABILITY):
             logger.error('Remote doesn not support CLI but sends AT+CLIP')
         self.cli_notification_enabled = True if enabled == b'1' else False
+        self.send_ok()
+
+    def _on_vgs(self, level: bytes) -> None:
+        self.emit('speaker_volume', int(level))
+        self.send_ok()
+
+    def _on_vgm(self, level: bytes) -> None:
+        self.emit('microphone_volume', int(level))
+        self.send_ok()
 
 
 # -----------------------------------------------------------------------------
@@ -1761,7 +1786,7 @@ def make_ag_sdp_records(
             sdp.SDP_SERVICE_CLASS_ID_LIST_ATTRIBUTE_ID,
             sdp.DataElement.sequence(
                 [
-                    sdp.DataElement.uuid(BT_HEADSET_AUDIO_GATEWAY_SERVICE),
+                    sdp.DataElement.uuid(BT_HANDSFREE_AUDIO_GATEWAY_SERVICE),
                     sdp.DataElement.uuid(BT_GENERIC_AUDIO_SERVICE),
                 ]
             ),
@@ -1788,7 +1813,7 @@ def make_ag_sdp_records(
                 [
                     sdp.DataElement.sequence(
                         [
-                            sdp.DataElement.uuid(BT_HEADSET_AUDIO_GATEWAY_SERVICE),
+                            sdp.DataElement.uuid(BT_HANDSFREE_AUDIO_GATEWAY_SERVICE),
                             sdp.DataElement.unsigned_integer_16(version),
                         ]
                     )
@@ -1820,6 +1845,7 @@ async def find_hf_sdp_record(
                 sdp.SDP_PROTOCOL_DESCRIPTOR_LIST_ATTRIBUTE_ID,
                 sdp.SDP_BLUETOOTH_PROFILE_DESCRIPTOR_LIST_ATTRIBUTE_ID,
                 sdp.SDP_SUPPORTED_FEATURES_ATTRIBUTE_ID,
+                sdp.SDP_SERVICE_CLASS_ID_LIST_ATTRIBUTE_ID,
             ],
         )
         for attribute_lists in search_result:
@@ -1839,10 +1865,17 @@ async def find_hf_sdp_record(
                     version = ProfileVersion(profile_descriptor_list[0].value[1].value)
                 elif attribute.id == sdp.SDP_SUPPORTED_FEATURES_ATTRIBUTE_ID:
                     features = HfSdpFeature(attribute.value.value)
-            if not channel or not version or features is None:
-                logger.warning(f"Bad result {attribute_lists}.")
-                return None
-            return (channel, version, features)
+                elif attribute.id == sdp.SDP_SERVICE_CLASS_ID_LIST_ATTRIBUTE_ID:
+                    class_id_list = attribute.value.value
+                    uuid = class_id_list[0].value
+                    # AG record may also contain HF UUID in its profile descriptor list.
+                    # If found, skip this record.
+                    if uuid == BT_HANDSFREE_AUDIO_GATEWAY_SERVICE:
+                        channel, version, features = (None, None, None)
+                        break
+
+            if channel is not None and version is not None and features is not None:
+                return (channel, version, features)
     return None
 
 
@@ -1859,7 +1892,7 @@ async def find_ag_sdp_record(
     """
     async with sdp.Client(connection) as sdp_client:
         search_result = await sdp_client.search_attributes(
-            uuids=[BT_HEADSET_AUDIO_GATEWAY_SERVICE],
+            uuids=[BT_HANDSFREE_AUDIO_GATEWAY_SERVICE],
             attribute_ids=[
                 sdp.SDP_PROTOCOL_DESCRIPTOR_LIST_ATTRIBUTE_ID,
                 sdp.SDP_BLUETOOTH_PROFILE_DESCRIPTOR_LIST_ATTRIBUTE_ID,

examples/hfp_gateway.html

@@ -0,0 +1,350 @@
+<html data-bs-theme="dark">
+
+<head>
+    <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.2/dist/css/bootstrap.min.css" rel="stylesheet"
+        integrity="sha384-T3c6CoIi6uLrA9TneNEoa7RxnatzjcDSCmG1MXxSR1GAsXEV/Dwwykc2MPK8M2HN" crossorigin="anonymous">
+    <script src="https://unpkg.com/pcm-player"></script>
+</head>
+
+<body>
+    <nav class="navbar navbar-dark bg-primary">
+        <div class="container">
+            <span class="navbar-brand mb-0 h1">Bumble HFP Audio Gateway</span>
+        </div>
+    </nav>
+    <br>
+
+    <div class="container">
+
+        <label class="form-label">Send AT Response</label>
+        <div class="input-group mb-3">
+            <input type="text" class="form-control" placeholder="AT Response" aria-label="AT response" id="at_response">
+            <button class="btn btn-primary" type="button"
+                onclick="send_at_response(document.getElementById('at_response').value)">Send</button>
+        </div>
+
+        <div class="row">
+            <div class="col-3">
+                <label class="form-label">Speaker Volume</label>
+                <div class="input-group mb-3 col-auto">
+                    <input type="text" class="form-control" placeholder="0 - 15" aria-label="Speaker Volume"
+                        id="speaker_volume">
+                    <button class="btn btn-primary" type="button"
+                        onclick="send_at_response(`+VGS: ${document.getElementById('speaker_volume').value}`)">Set</button>
+                </div>
+            </div>
+            <div class="col-3">
+                <label class="form-label">Mic Volume</label>
+                <div class="input-group mb-3 col-auto">
+                    <input type="text" class="form-control" placeholder="0 - 15" aria-label="Mic Volume"
+                        id="mic_volume">
+                    <button class="btn btn-primary" type="button"
+                        onclick="send_at_response(`+VGM: ${document.getElementById('mic_volume').value}`)">Set</button>
+                </div>
+            </div>
+            <div class="col-3">
+                <label class="form-label">Browser Gain</label>
+                <input type="range" class="form-range" id="browser-gain" min="0" max="2" value="1" step="0.1" onchange="setGain()">
+            </div>
+        </div>
+
+        <div class="row">
+            <div class="col-auto">
+                <div class="input-group mb-3">
+                    <span class="input-group-text">Codec</span>
+
+                    <select class="form-select" id="codec">
+                        <option selected value="1">CVSD</option>
+                        <option value="2">MSBC</option>
+                    </select>
+                </div>
+            </div>
+
+            <div class="col-auto">
+                <button class="btn btn-primary" onclick="negotiate_codec()">Negotiate Codec</button>
+            </div>
+            <div class="col-auto">
+                <button class="btn btn-primary" onclick="connect_sco()">Connect SCO</button>
+            </div>
+            <div class="col-auto">
+                <button class="btn btn-primary" onclick="disconnect_sco()">Disconnect SCO</button>
+            </div>
+            <div class="col-auto">
+                <button class="btn btn-danger" onclick="connectAudio()">Connect Audio</button>
+            </div>
+        </div>
+
+        <hr>
+
+        <div class="row">
+            <h4>AG Indicators</h2>
+                <div class="col-3">
+                    <label class="form-label">call</label>
+                    <div class="input-group mb-3 col-auto">
+                        <select class="form-select" id="call">
+                            <option selected value="0">Inactive</option>
+                            <option value="1">Active</option>
+                        </select>
+                        <button class="btn btn-primary" type="button" onclick="update_ag_indicator('call')">Set</button>
+                    </div>
+                </div>
+                <div class="col-3">
+                    <label class="form-label">callsetup</label>
+                    <div class="input-group mb-3 col-auto">
+                        <select class="form-select" id="callsetup">
+                            <option selected value="0">Idle</option>
+                            <option value="1">Incoming</option>
+                            <option value="2">Outgoing</option>
+                            <option value="3">Remote Alerted</option>
+                        </select>
+                        <button class="btn btn-primary" type="button"
+                            onclick="update_ag_indicator('callsetup')">Set</button>
+                    </div>
+                </div>
+                <div class="col-3">
+                    <label class="form-label">callheld</label>
+                    <div class="input-group mb-3 col-auto">
+                        <select class="form-select" id="callsetup">
+                            <option selected value="0">0</option>
+                            <option value="1">1</option>
+                            <option value="2">2</option>
+                        </select>
+                        <button class="btn btn-primary" type="button"
+                            onclick="update_ag_indicator('callheld')">Set</button>
+                    </div>
+                </div>
+                <div class="col-3">
+                    <label class="form-label">signal</label>
+                    <div class="input-group mb-3 col-auto">
+                        <select class="form-select" id="signal">
+                            <option selected value="0">0</option>
+                            <option value="1">1</option>
+                            <option value="2">2</option>
+                            <option value="3">3</option>
+                            <option value="4">4</option>
+                            <option value="5">5</option>
+                        </select>
+                        <button class="btn btn-primary" type="button"
+                            onclick="update_ag_indicator('signal')">Set</button>
+                    </div>
+                </div>
+                <div class="col-3">
+                    <label class="form-label">roam</label>
+                    <div class="input-group mb-3 col-auto">
+                        <select class="form-select" id="roam">
+                            <option selected value="0">0</option>
+                            <option value="1">1</option>
+                        </select>
+                        <button class="btn btn-primary" type="button" onclick="update_ag_indicator('roam')">Set</button>
+                    </div>
+                </div>
+                <div class="col-3">
+                    <label class="form-label">battchg</label>
+                    <div class="input-group mb-3 col-auto">
+                        <select class="form-select" id="battchg">
+                            <option selected value="0">0</option>
+                            <option value="1">1</option>
+                            <option value="2">2</option>
+                            <option value="3">3</option>
+                            <option value="4">4</option>
+                            <option value="5">5</option>
+                        </select>
+                        <button class="btn btn-primary" type="button"
+                            onclick="update_ag_indicator('battchg')">Set</button>
+                    </div>
+                </div>
+                <div class="col-3">
+                    <label class="form-label">service</label>
+                    <div class="input-group mb-3 col-auto">
+                        <select class="form-select" id="service">
+                            <option selected value="0">0</option>
+                            <option value="1">1</option>
+                        </select>
+                        <button class="btn btn-primary" type="button"
+                            onclick="update_ag_indicator('service')">Set</button>
+                    </div>
+                </div>
+        </div>
+
+        <hr>
+
+        <button class="btn btn-primary" onclick="send_at_response('+BVRA: 1')">Start Voice Assistant</button>
+        <button class="btn btn-primary" onclick="send_at_response('+BVRA: 0')">Stop Voice Assistant</button>
+
+        <hr>
+
+
+        <h4>Calls</h4>
+        <div id="call-lists">
+            <template id="call-template">
+                <div class="row call-row">
+                    <div class="input-group mb-3">
+                        <label class="input-group-text">Index</label>
+                        <input class="form-control call-index" value="1">
+
+                        <label class="input-group-text">Number</label>
+                        <input class="form-control call-number">
+
+                        <label class="input-group-text">Direction</label>
+                        <select class="form-select call-direction">
+                            <option selected value="0">Originated</option>
+                            <option value="1">Terminated</option>
+                        </select>
+
+                        <label class="input-group-text">Status</label>
+                        <select class="form-select call-status">
+                            <option value="0">ACTIVE</option>
+                            <option value="1">HELD</option>
+                            <option value="2">DIALING</option>
+                            <option value="3">ALERTING</option>
+                            <option value="4">INCOMING</option>
+                            <option value="5">WAITING</option>
+                        </select>
+                        <button class="btn btn-primary call-remover">❌</button>
+                    </div>
+                </div>
+            </template>
+        </div>
+
+        <button class="btn btn-primary" onclick="add_call()">➕ Add Call</button>
+        <button class="btn btn-primary" onclick="update_calls()">🗘 Update Calls</button>
+
+        <hr>
+
+        <div id="socketStateContainer" class="bg-body-tertiary p-3 rounded-2">
+            <h3>Log</h3>
+            <code id="log" style="white-space: pre-line;"></code>
+        </div>
+    </div>
+
+
+    <script>
+        let atResponseInput = document.getElementById("at_response")
+        let gainInput = document.getElementById('browser-gain')
+        let log = document.getElementById("log")
+        let socket = new WebSocket('ws://localhost:8888');
+        let sampleRate = 0;
+        let player;
+
+        socket.binaryType = "arraybuffer";
+        socket.onopen = _ => {
+            log.textContent += 'SOCKET OPEN\n'
+        }
+        socket.onclose = _ => {
+            log.textContent += 'SOCKET CLOSED\n'
+        }
+        socket.onerror = (error) => {
+            log.textContent += 'SOCKET ERROR\n'
+            console.log(`ERROR: ${error}`)
+        }
+        socket.onmessage = function (message) {
+            if (typeof message.data === 'string' || message.data instanceof String) {
+                log.textContent += `<-- ${event.data}\n`
+                const jsonMessage = JSON.parse(event.data)
+
+                if (jsonMessage.type == 'speaker_volume') {
+                    document.getElementById('speaker_volume').value = jsonMessage.level;
+                } else if (jsonMessage.type == 'microphone_volume') {
+                    document.getElementById('microphone_volume').value = jsonMessage.level;
+                } else if (jsonMessage.type == 'sco_state_change') {
+                    sampleRate = jsonMessage.sample_rate;
+                    console.log(sampleRate);
+                    if (player != null) {
+                        player = new PCMPlayer({
+                            inputCodec: 'Int16',
+                            channels: 1,
+                            sampleRate: sampleRate,
+                            flushTime: 7.5,
+                        });
+                        player.volume(gainInput.value);
+                    }
+                }
+            } else {
+                // BINARY audio data.
+                if (player == null) return;
+                player.feed(message.data);
+            }
+        };
+
+        function send(message) {
+            if (socket && socket.readyState == WebSocket.OPEN) {
+                let jsonMessage = JSON.stringify(message)
+                log.textContent += `--> ${jsonMessage}\n`
+                socket.send(jsonMessage)
+            } else {
+                log.textContent += 'NOT CONNECTED\n'
+            }
+        }
+
+        function send_at_response(response) {
+            send({ type: 'at_response', response: response })
+        }
+
+        function update_ag_indicator(indicator) {
+            const value = document.getElementById(indicator).value
+            send({ type: 'ag_indicator', indicator: indicator, value: value })
+        }
+
+        function connect_sco() {
+            send({ type: 'connect_sco' })
+        }
+
+        function negotiate_codec() {
+            const codec = document.getElementById('codec').value
+            send({ type: 'negotiate_codec', codec: codec })
+        }
+
+        function disconnect_sco() {
+            send({ type: 'disconnect_sco' })
+        }
+
+        function add_call() {
+            let callLists = document.getElementById('call-lists');
+            let template = document.getElementById('call-template');
+
+            let newNode = document.importNode(template.content, true);
+            newNode.querySelector('.call-remover').onclick = function (event) {
+                event.target.closest('.call-row').remove();
+            }
+            callLists.appendChild(newNode);
+        }
+
+        function update_calls() {
+            let callLists = document.getElementById('call-lists');
+            send({
+                type: 'update_calls',
+                calls: Array.from(
+                    callLists.querySelectorAll('.call-row')).map(
+                        function (element) {
+                            return {
+                                index: element.querySelector('.call-index').value,
+                                number: element.querySelector('.call-number').value,
+                                direction: element.querySelector('.call-direction').value,
+                                status: element.querySelector('.call-status').value,
+                            }
+                        }
+                    ),
+            }
+            )
+        }
+
+        function connectAudio() {
+            player = new PCMPlayer({
+                inputCodec: 'Int16',
+                channels: 1,
+                sampleRate: sampleRate,
+                flushTime: 7.5,
+            });
+            player.volume(gainInput.value);
+        }
+
+        function setGain() {
+            if (player != null) {
+                player.volume(gainInput.value);
+            }
+        }
+    </script>
+    </div>
+</body>
+
+</html>

examples/hfp_gateway.json

@@ -1,4 +1,5 @@
 {
     "name": "Bumble Phone",
-    "class_of_device": 6291980
+    "class_of_device": 6291980,
+    "keystore": "JsonKeyStore"
 }

examples/run_hfp_gateway.py

@@ -16,9 +16,14 @@
 # Imports
 # -----------------------------------------------------------------------------
 import asyncio
+import json
 import sys
 import os
+import io
 import logging
+import websockets
+
+from typing import Optional
 
 import bumble.core
 from bumble.device import Device
@@ -26,12 +31,15 @@ from bumble.transport import open_transport_or_link
 from bumble.core import (
     BT_BR_EDR_TRANSPORT,
 )
-from bumble import rfcomm, hfp
-from bumble.hci import HCI_SynchronousDataPacket
+from bumble import hci, rfcomm, hfp
 
 
 logger = logging.getLogger(__name__)
 
+ws: Optional[websockets.WebSocketServerProtocol] = None
+ag_protocol: Optional[hfp.AgProtocol] = None
+source_file: Optional[io.BufferedReader] = None
+
 
 def _default_configuration() -> hfp.AgConfiguration:
     return hfp.AgConfiguration(
@@ -41,12 +49,13 @@ def _default_configuration() -> hfp.AgConfiguration:
             hfp.AgFeature.REJECT_CALL,
             hfp.AgFeature.CODEC_NEGOTIATION,
             hfp.AgFeature.ESCO_S4_SETTINGS_SUPPORTED,
+            hfp.AgFeature.ENHANCED_CALL_STATUS,
         ],
         supported_ag_indicators=[
             hfp.AgIndicatorState.call(),
+            hfp.AgIndicatorState.callsetup(),
+            hfp.AgIndicatorState.callheld(),
             hfp.AgIndicatorState.service(),
-            hfp.AgIndicatorState.callsetup(),
-            hfp.AgIndicatorState.callsetup(),
             hfp.AgIndicatorState.signal(),
             hfp.AgIndicatorState.roam(),
             hfp.AgIndicatorState.battchg(),
@@ -60,17 +69,123 @@ def _default_configuration() -> hfp.AgConfiguration:
     )
 
 
+def send_message(type: str, **kwargs) -> None:
+    if ws:
+        asyncio.create_task(ws.send(json.dumps({'type': type, **kwargs})))
+
+
+def on_speaker_volume(level: int):
+    send_message(type='speaker_volume', level=level)
+
+
+def on_microphone_volume(level: int):
+    send_message(type='microphone_volume', level=level)
+
+
+def on_sco_state_change(codec: int):
+    if codec == hfp.AudioCodec.CVSD:
+        sample_rate = 8000
+    elif codec == hfp.AudioCodec.MSBC:
+        sample_rate = 16000
+    else:
+        sample_rate = 0
+
+    send_message(type='sco_state_change', sample_rate=sample_rate)
+
+
+def on_sco_packet(packet: hci.HCI_SynchronousDataPacket):
+    if ws:
+        asyncio.create_task(ws.send(packet.data))
+    if source_file and (pcm_data := source_file.read(packet.data_total_length)):
+        assert ag_protocol
+        host = ag_protocol.dlc.multiplexer.l2cap_channel.connection.device.host
+        host.send_hci_packet(
+            hci.HCI_SynchronousDataPacket(
+                connection_handle=packet.connection_handle,
+                packet_status=0,
+                data_total_length=len(pcm_data),
+                data=pcm_data,
+            )
+        )
+
+
+def on_hfp_state_change(connected: bool):
+    send_message(type='hfp_state_change', connected=connected)
+
+
+async def ws_server(ws_client: websockets.WebSocketServerProtocol, path: str):
+    del path
+    global ws
+    ws = ws_client
+
+    async for message in ws_client:
+        if not ag_protocol:
+            continue
+
+        json_message = json.loads(message)
+        message_type = json_message['type']
+        connection = ag_protocol.dlc.multiplexer.l2cap_channel.connection
+        device = connection.device
+
+        try:
+            if message_type == 'at_response':
+                ag_protocol.send_response(json_message['response'])
+            elif message_type == 'ag_indicator':
+                ag_protocol.update_ag_indicator(
+                    hfp.AgIndicator(json_message['indicator']),
+                    int(json_message['value']),
+                )
+            elif message_type == 'negotiate_codec':
+                codec = hfp.AudioCodec(int(json_message['codec']))
+                await ag_protocol.negotiate_codec(codec)
+            elif message_type == 'connect_sco':
+                if ag_protocol.active_codec == hfp.AudioCodec.CVSD:
+                    esco_param = hfp.ESCO_PARAMETERS[
+                        hfp.DefaultCodecParameters.ESCO_CVSD_S4
+                    ]
+                elif ag_protocol.active_codec == hfp.AudioCodec.MSBC:
+                    esco_param = hfp.ESCO_PARAMETERS[
+                        hfp.DefaultCodecParameters.ESCO_MSBC_T2
+                    ]
+                else:
+                    raise ValueError(f'Unsupported codec {codec}')
+
+                await device.send_command(
+                    hci.HCI_Enhanced_Setup_Synchronous_Connection_Command(
+                        connection_handle=connection.handle, **esco_param.asdict()
+                    )
+                )
+            elif message_type == 'disconnect_sco':
+                # Copy the values to avoid iteration error.
+                for sco_link in list(device.sco_links.values()):
+                    await sco_link.disconnect()
+            elif message_type == 'update_calls':
+                ag_protocol.calls = [
+                    hfp.CallInfo(
+                        index=int(call['index']),
+                        direction=hfp.CallInfoDirection(int(call['direction'])),
+                        status=hfp.CallInfoStatus(int(call['status'])),
+                        number=call['number'],
+                        multi_party=hfp.CallInfoMultiParty.NOT_IN_CONFERENCE,
+                        mode=hfp.CallInfoMode.VOICE,
+                    )
+                    for call in json_message['calls']
+                ]
+
+        except Exception as e:
+            send_message(type='error', message=e)
+
+
 # -----------------------------------------------------------------------------
 async def main() -> None:
-    if len(sys.argv) < 4:
+    if len(sys.argv) < 3:
         print(
             'Usage: run_hfp_gateway.py <device-config> <transport-spec> '
-            '<bluetooth-address>'
+            '[bluetooth-address] [wav-file-for-source]'
         )
         print(
-            '  specifying a channel number, or "discover" to list all RFCOMM channels'
+            'example: run_hfp_gateway.py hfp_gateway.json usb:0 E1:CA:72:48:C4:E8 sample.wav'
         )
-        print('example: run_hfp_gateway.py hfp_gateway.json usb:0 E1:CA:72:48:C4:E8')
         return
 
     print('<<< connecting to HCI...')
@@ -84,56 +199,85 @@ async def main() -> None:
         device.classic_enabled = True
         await device.power_on()
 
-        # Connect to a peer
-        target_address = sys.argv[3]
-        print(f'=== Connecting to {target_address}...')
-        connection = await device.connect(target_address, transport=BT_BR_EDR_TRANSPORT)
-        print(f'=== Connected to {connection.peer_address}!')
+        rfcomm_server = rfcomm.Server(device)
+        configuration = _default_configuration()
 
-        # Get a list of all the Handsfree services (should only be 1)
-        if not (hfp_record := await hfp.find_hf_sdp_record(connection)):
-            print('!!! no service found')
-            return
+        def on_dlc(dlc: rfcomm.DLC):
+            global ag_protocol
+            ag_protocol = hfp.AgProtocol(dlc, configuration)
+            ag_protocol.on('speaker_volume', on_speaker_volume)
+            ag_protocol.on('microphone_volume', on_microphone_volume)
+            on_hfp_state_change(True)
+            dlc.multiplexer.l2cap_channel.on(
+                'close', lambda: on_hfp_state_change(False)
+            )
 
-        # Pick the first one
-        channel, version, hf_sdp_features = hfp_record
-        print(f'HF version: {version}')
-        print(f'HF features: {hf_sdp_features}')
+        channel = rfcomm_server.listen(on_dlc)
+        device.sdp_service_records = {
+            1: hfp.make_ag_sdp_records(1, channel, configuration)
+        }
 
-        # Request authentication
-        print('*** Authenticating...')
-        await connection.authenticate()
-        print('*** Authenticated')
+        def on_sco_connection(sco_link):
+            assert ag_protocol
+            on_sco_state_change(ag_protocol.active_codec)
+            sco_link.on('disconnection', lambda _: on_sco_state_change(0))
+            sco_link.on('pdu', on_sco_packet)
 
-        # Enable encryption
-        print('*** Enabling encryption...')
-        await connection.encrypt()
-        print('*** Encryption on')
+        device.on('sco_connection', on_sco_connection)
+        if len(sys.argv) >= 4:
+            # Connect to a peer
+            target_address = sys.argv[3]
+            print(f'=== Connecting to {target_address}...')
+            connection = await device.connect(
+                target_address, transport=BT_BR_EDR_TRANSPORT
+            )
+            print(f'=== Connected to {connection.peer_address}!')
 
-        # Create a client and start it
-        print('@@@ Starting to RFCOMM client...')
-        rfcomm_client = rfcomm.Client(connection)
-        rfcomm_mux = await rfcomm_client.start()
-        print('@@@ Started')
+            # Get a list of all the Handsfree services (should only be 1)
+            if not (hfp_record := await hfp.find_hf_sdp_record(connection)):
+                print('!!! no service found')
+                return
 
-        print(f'### Opening session for channel {channel}...')
-        try:
-            session = await rfcomm_mux.open_dlc(channel)
-            print('### Session open', session)
-        except bumble.core.ConnectionError as error:
-            print(f'### Session open failed: {error}')
-            await rfcomm_mux.disconnect()
-            print('@@@ Disconnected from RFCOMM server')
-            return
+            # Pick the first one
+            channel, version, hf_sdp_features = hfp_record
+            print(f'HF version: {version}')
+            print(f'HF features: {hf_sdp_features}')
 
-        def on_sco(connection_handle: int, packet: HCI_SynchronousDataPacket):
-            # Reset packet and loopback
-            packet.packet_status = 0
-            device.host.send_hci_packet(packet)
+            # Request authentication
+            print('*** Authenticating...')
+            await connection.authenticate()
+            print('*** Authenticated')
 
-        device.host.on('sco_packet', on_sco)
+            # Enable encryption
+            print('*** Enabling encryption...')
+            await connection.encrypt()
+            print('*** Encryption on')
 
-        ag_protocol = hfp.AgProtocol(session, _default_configuration())
+            # Create a client and start it
+            print('@@@ Starting to RFCOMM client...')
+            rfcomm_client = rfcomm.Client(connection)
+            rfcomm_mux = await rfcomm_client.start()
+            print('@@@ Started')
+
+            print(f'### Opening session for channel {channel}...')
+            try:
+                session = await rfcomm_mux.open_dlc(channel)
+                print('### Session open', session)
+            except bumble.core.ConnectionError as error:
+                print(f'### Session open failed: {error}')
+                await rfcomm_mux.disconnect()
+                print('@@@ Disconnected from RFCOMM server')
+                return
+
+            on_dlc(session)
+
+        await websockets.serve(ws_server, port=8888)
+
+        if len(sys.argv) >= 5:
+            global source_file
+            source_file = open(sys.argv[4], 'rb')
+            # Skip header
+            source_file.seek(44)
 
         await hci_transport.source.terminated