xref: /btstack/src/classic/a2dp_source.c (revision a8d51f092f1b660d0f6921369ad2bc3f9368296c)
1 
2 /*
3  * Copyright (C) 2016 BlueKitchen GmbH
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. Neither the name of the copyright holders nor the names of
15  *    contributors may be used to endorse or promote products derived
16  *    from this software without specific prior written permission.
17  * 4. Any redistribution, use, or modification is done solely for
18  *    personal benefit and not for any commercial purpose or for
19  *    monetary gain.
20  *
21  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
25  * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
28  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
31  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  * Please inquire about commercial licensing options at
35  * [email protected]
36  *
37  */
38 
39 /**
40  * Supported use cases:
41  * - single incoming connection: sep discovery starts and stream will get setup if remote sink sep with SBC is found
42  * - single outgoing connection: see above
43  * - outgoing and incoming connection to same device:
44  *    - if outgoing is triggered first, incoming will get ignored.
45  *    - if incoming starts first, start ougoing will fail, but incoming will succeed.
46  * - outgoing and incoming connections to different devices:
47  *    - if outgoing is first, incoming gets ignored.
48  *    - if incoming starts first SEP discovery will get stopped and outgoing will succeed.
49  */
50 
51 #define BTSTACK_FILE__ "a2dp_source.c"
52 
53 #include <stdint.h>
54 #include <string.h>
55 
56 #include "bluetooth_psm.h"
57 #include "bluetooth_sdp.h"
58 #include "btstack_debug.h"
59 #include "btstack_event.h"
60 #include "classic/a2dp_source.h"
61 #include "classic/avdtp_source.h"
62 #include "classic/avdtp_util.h"
63 #include "classic/sdp_util.h"
64 #include "l2cap.h"
65 
66 #define AVDTP_MAX_SEP_NUM 10
67 #define A2DP_SET_CONFIG_DELAY_MS 150
68 
69 static const char * default_a2dp_source_service_name = "BTstack A2DP Source Service";
70 static const char * default_a2dp_source_service_provider_name = "BTstack A2DP Source Service Provider";
71 static bool sep_found_w2_set_configuration = false;
72 static btstack_timer_source_t a2dp_source_set_config_timer;
73 
74 //
75 static bool     outgoing_active;
76 
77 // discover remote seps
78 static a2dp_state_t a2dp_source_state = A2DP_IDLE;
79 static uint16_t     a2dp_source_cid;
80 static uint16_t     num_remote_seps = 0;
81 static avdtp_sep_t  remote_seps[AVDTP_MAX_SEP_NUM];
82 
83 static bool stream_endpoint_configured = false;
84 
85 static avdtp_stream_endpoint_context_t sc;
86 static btstack_packet_handler_t a2dp_source_packet_handler_user;
87 
88 static void a2dp_source_packet_handler_internal(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
89 static void a2dp_discover_seps_with_next_waiting_connection(void);
90 
91 static void a2dp_source_streaming_emit_connection_failed(avdtp_connection_t * connection, uint8_t local_seid, uint8_t status) {
92     uint8_t event[14];
93     int pos = 0;
94     event[pos++] = HCI_EVENT_A2DP_META;
95     event[pos++] = sizeof(event) - 2;
96     event[pos++] = A2DP_SUBEVENT_STREAM_ESTABLISHED;
97     little_endian_store_16(event, pos, connection->avdtp_cid);
98     pos += 2;
99     reverse_bd_addr(connection->remote_addr, &event[pos]);
100     pos += 6;
101     event[pos++] = local_seid;
102     event[pos++] = 0;
103     event[pos++] = status;
104 
105     (*a2dp_source_packet_handler_user)(HCI_EVENT_PACKET, 0, event, sizeof(event));
106 }
107 
108 void a2dp_source_create_sdp_record(uint8_t * service, uint32_t service_record_handle, uint16_t supported_features, const char * service_name, const char * service_provider_name){
109     uint8_t* attribute;
110     de_create_sequence(service);
111 
112     // 0x0000 "Service Record Handle"
113     de_add_number(service, DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_SERVICE_RECORD_HANDLE);
114     de_add_number(service, DE_UINT, DE_SIZE_32, service_record_handle);
115 
116     // 0x0001 "Service Class ID List"
117     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_SERVICE_CLASS_ID_LIST);
118     attribute = de_push_sequence(service);
119     {
120         de_add_number(attribute, DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_AUDIO_SOURCE);
121     }
122     de_pop_sequence(service, attribute);
123 
124     // 0x0004 "Protocol Descriptor List"
125     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_PROTOCOL_DESCRIPTOR_LIST);
126     attribute = de_push_sequence(service);
127     {
128         uint8_t* l2cpProtocol = de_push_sequence(attribute);
129         {
130             de_add_number(l2cpProtocol,  DE_UUID, DE_SIZE_16, BLUETOOTH_PROTOCOL_L2CAP);
131             de_add_number(l2cpProtocol,  DE_UINT, DE_SIZE_16, BLUETOOTH_PSM_AVDTP);
132         }
133         de_pop_sequence(attribute, l2cpProtocol);
134 
135         uint8_t* avProtocol = de_push_sequence(attribute);
136         {
137             de_add_number(avProtocol,  DE_UUID, DE_SIZE_16, BLUETOOTH_PROTOCOL_AVDTP);  // avProtocol_service
138             de_add_number(avProtocol,  DE_UINT, DE_SIZE_16,  0x0103);  // version
139         }
140         de_pop_sequence(attribute, avProtocol);
141     }
142     de_pop_sequence(service, attribute);
143 
144     // 0x0005 "Public Browse Group"
145     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_BROWSE_GROUP_LIST); // public browse group
146     attribute = de_push_sequence(service);
147     {
148         de_add_number(attribute,  DE_UUID, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_PUBLIC_BROWSE_ROOT);
149     }
150     de_pop_sequence(service, attribute);
151 
152     // 0x0009 "Bluetooth Profile Descriptor List"
153     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_BLUETOOTH_PROFILE_DESCRIPTOR_LIST);
154     attribute = de_push_sequence(service);
155     {
156         uint8_t *a2dProfile = de_push_sequence(attribute);
157         {
158             de_add_number(a2dProfile,  DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_ADVANCED_AUDIO_DISTRIBUTION);
159             de_add_number(a2dProfile,  DE_UINT, DE_SIZE_16, 0x0103);
160         }
161         de_pop_sequence(attribute, a2dProfile);
162     }
163     de_pop_sequence(service, attribute);
164 
165 
166     // 0x0100 "Service Name"
167     de_add_number(service,  DE_UINT, DE_SIZE_16, 0x0100);
168     if (service_name){
169         de_add_data(service,  DE_STRING, strlen(service_name), (uint8_t *) service_name);
170     } else {
171         de_add_data(service,  DE_STRING, strlen(default_a2dp_source_service_name), (uint8_t *) default_a2dp_source_service_name);
172     }
173 
174     // 0x0100 "Provider Name"
175     de_add_number(service,  DE_UINT, DE_SIZE_16, 0x0102);
176     if (service_provider_name){
177         de_add_data(service,  DE_STRING, strlen(service_provider_name), (uint8_t *) service_provider_name);
178     } else {
179         de_add_data(service,  DE_STRING, strlen(default_a2dp_source_service_provider_name), (uint8_t *) default_a2dp_source_service_provider_name);
180     }
181 
182     // 0x0311 "Supported Features"
183     de_add_number(service, DE_UINT, DE_SIZE_16, 0x0311);
184     de_add_number(service, DE_UINT, DE_SIZE_16, supported_features);
185 }
186 
187 static void a2dp_signaling_emit_reconfigured(uint16_t cid, uint8_t local_seid, uint8_t status){
188     uint8_t event[7];
189     int pos = 0;
190     event[pos++] = HCI_EVENT_A2DP_META;
191     event[pos++] = sizeof(event) - 2;
192     event[pos++] = A2DP_SUBEVENT_STREAM_RECONFIGURED;
193     little_endian_store_16(event, pos, cid);
194     pos += 2;
195     event[pos++] = local_seid;
196     event[pos++] = status;
197     (*a2dp_source_packet_handler_user)(HCI_EVENT_PACKET, 0, event, sizeof(event));
198 }
199 
200 static void a2dp_source_discover_stream_endpoints(uint16_t avdtp_cid){
201     a2dp_source_cid = avdtp_cid;
202     avdtp_source_discover_stream_endpoints(avdtp_cid);
203 }
204 
205 static void a2dp_source_set_config_timer_handler(btstack_timer_source_t * timer){
206     if (stream_endpoint_configured) return;
207 
208     uint16_t avdtp_cid = (uint16_t)(uintptr_t) btstack_run_loop_get_timer_context(timer);
209 	avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
210 	btstack_run_loop_set_timer_context(&a2dp_source_set_config_timer, NULL);
211 
212     if (connection == NULL) {
213         log_info("a2dp_discover_seps_with_next_waiting_connection");
214         a2dp_discover_seps_with_next_waiting_connection();
215         return;
216     }
217 
218     a2dp_source_discover_stream_endpoints(avdtp_cid);
219 }
220 
221 static void a2dp_source_set_config_timer_start(uint16_t avdtp_cid){
222     log_info("a2dp_source_set_config_timer_start cid 0%02x", avdtp_cid);
223     btstack_run_loop_remove_timer(&a2dp_source_set_config_timer);
224     btstack_run_loop_set_timer_handler(&a2dp_source_set_config_timer,a2dp_source_set_config_timer_handler);
225     btstack_run_loop_set_timer(&a2dp_source_set_config_timer, A2DP_SET_CONFIG_DELAY_MS);
226     btstack_run_loop_set_timer_context(&a2dp_source_set_config_timer, (void *)(uintptr_t)avdtp_cid);
227     btstack_run_loop_add_timer(&a2dp_source_set_config_timer);
228 }
229 
230 static void a2dp_source_set_config_timer_stop(void){
231     log_info("a2dp_source_set_config_timer_stop");
232     btstack_run_loop_remove_timer(&a2dp_source_set_config_timer);
233 	btstack_run_loop_set_timer_context(&a2dp_source_set_config_timer, NULL);
234 }
235 
236 static void a2dp_start_discovering_seps(avdtp_connection_t * connection){
237     a2dp_source_state = A2DP_DISCOVER_SEPS;
238     sc.active_remote_sep_index = 0;
239     num_remote_seps = 0;
240     memset(remote_seps, 0, sizeof(avdtp_sep_t) * AVDTP_MAX_SEP_NUM);
241     connection->a2dp_source_discover_seps = false;
242 
243     // if we initiated the connection, start config right away, else wait a bit to give remote a chance to do it first
244     if (outgoing_active && (a2dp_source_cid == connection->avdtp_cid)){
245         log_info("discover seps");
246         a2dp_source_discover_stream_endpoints(connection->avdtp_cid);
247     } else {
248         log_info("wait a bit, then discover seps");
249         a2dp_source_set_config_timer_start(connection->avdtp_cid);
250     }
251 }
252 
253 static void a2dp_discover_seps_with_next_waiting_connection(void){
254     a2dp_source_state = A2DP_IDLE;
255 
256     btstack_linked_list_iterator_t it;
257     btstack_linked_list_iterator_init(&it, avdtp_get_connections());
258     while (btstack_linked_list_iterator_has_next(&it)){
259         avdtp_connection_t * next_connection = (avdtp_connection_t *)btstack_linked_list_iterator_next(&it);
260         if (!next_connection->a2dp_source_discover_seps) continue;
261         a2dp_start_discovering_seps(next_connection);
262     }
263 }
264 
265 static void a2dp_source_packet_handler_internal(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
266     UNUSED(channel);
267     UNUSED(size);
268 
269     uint16_t cid;
270     avdtp_connection_t * connection;
271 
272     uint8_t signal_identifier;
273     uint8_t status;
274     uint8_t remote_seid;
275 
276     if (packet_type != HCI_EVENT_PACKET) return;
277     if (hci_event_packet_get_type(packet) != HCI_EVENT_AVDTP_META) return;
278 
279     switch (packet[2]){
280         case AVDTP_SUBEVENT_SIGNALING_CONNECTION_ESTABLISHED:
281             if (sc.local_stream_endpoint == NULL) return;
282 
283             cid = avdtp_subevent_signaling_connection_established_get_avdtp_cid(packet);
284             connection = avdtp_get_connection_for_avdtp_cid(cid);
285             btstack_assert(connection != NULL);
286 
287             status = avdtp_subevent_signaling_connection_established_get_status(packet);
288             if (status != ERROR_CODE_SUCCESS){
289                 // notify about connection error only if we're initiator
290                 if (outgoing_active && (a2dp_source_cid == cid)){
291                     log_info("A2DP source signaling connection failed status 0x%02x", status);
292                     outgoing_active = false;
293                     a2dp_replace_subevent_id_and_emit_cmd(a2dp_source_packet_handler_user, packet, size, A2DP_SUBEVENT_SIGNALING_CONNECTION_ESTABLISHED);
294                 }
295                 break;
296             }
297             log_info("A2DP source signaling connection established avdtp_cid 0x%02x", cid);
298 
299             // notify app
300             a2dp_replace_subevent_id_and_emit_cmd(a2dp_source_packet_handler_user, packet, size, A2DP_SUBEVENT_SIGNALING_CONNECTION_ESTABLISHED);
301 
302             // we already have a valid setup
303             if (stream_endpoint_configured) return;
304 
305             // start discover seps now if:
306             // - outgoing active: signaling for outgoing connection
307             // - outgoing not active: incoming connection and no sep discover ongoing
308 
309             log_info("outgoing_active %d, current avdtp cid 0x%02x, a2dp_source_state %d", outgoing_active, cid, a2dp_source_state);
310             if ((outgoing_active && (a2dp_source_cid == cid)) || (!outgoing_active && (a2dp_source_state == A2DP_IDLE))){
311                 a2dp_start_discovering_seps(connection);
312             } else {
313                 // post-pone sep discovery
314                 connection->a2dp_source_discover_seps = true;
315             }
316             break;
317 
318         case AVDTP_SUBEVENT_SIGNALING_SEP_FOUND:
319             cid = avdtp_subevent_signaling_sep_found_get_avdtp_cid(packet);
320             if (a2dp_source_cid != cid) break;
321             if (a2dp_source_state == A2DP_DISCOVER_SEPS) {
322                 avdtp_sep_t sep;
323                 sep.seid       = avdtp_subevent_signaling_sep_found_get_remote_seid(packet);;
324                 sep.in_use     = avdtp_subevent_signaling_sep_found_get_in_use(packet);
325                 sep.media_type = (avdtp_media_type_t) avdtp_subevent_signaling_sep_found_get_media_type(packet);
326                 sep.type       = (avdtp_sep_type_t) avdtp_subevent_signaling_sep_found_get_sep_type(packet);
327                 log_info("A2DP Found sep: remote seid 0x%02x, in_use %d, media type %d, sep type %s, index %d",
328                          sep.seid, sep.in_use, sep.media_type, sep.type == AVDTP_SOURCE ? "source" : "sink",
329                          num_remote_seps);
330                 if (sep.type == AVDTP_SINK) {
331                     remote_seps[num_remote_seps++] = sep;
332                 }
333             }
334             break;
335 
336         case AVDTP_SUBEVENT_SIGNALING_SEP_DICOVERY_DONE:
337             cid = avdtp_subevent_signaling_sep_dicovery_done_get_avdtp_cid(packet);
338             if (a2dp_source_cid != cid) break;
339             if (a2dp_source_state != A2DP_DISCOVER_SEPS) break;
340 
341             connection = avdtp_get_connection_for_avdtp_cid(cid);
342             btstack_assert(connection != NULL);
343 
344             if (num_remote_seps > 0){
345                 a2dp_source_state = A2DP_GET_CAPABILITIES;
346                 connection->supported_codecs_bitmap = 0;
347                 sc.active_remote_sep_index = 0;
348             } else {
349                 if (outgoing_active){
350                     outgoing_active = false;
351                     connection = avdtp_get_connection_for_avdtp_cid(cid);
352                     btstack_assert(connection != NULL);
353                     a2dp_source_streaming_emit_connection_failed(connection, sc.local_stream_endpoint->sep.seid, ERROR_CODE_CONNECTION_REJECTED_DUE_TO_NO_SUITABLE_CHANNEL_FOUND);
354                 }
355 
356                 // continue
357                 a2dp_discover_seps_with_next_waiting_connection();
358             }
359             break;
360 
361         case AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_SBC_CAPABILITY:
362             cid = avdtp_subevent_signaling_media_codec_sbc_capability_get_avdtp_cid(packet);
363             if (a2dp_source_cid != cid) break;
364             if (a2dp_source_state == A2DP_GET_CAPABILITIES) {
365 
366                 log_info("A2DP received SBC capability, received: remote seid 0x%02x (expected: remote seid 0x%02x)",
367                     avdtp_subevent_signaling_media_codec_sbc_capability_get_remote_seid(packet), remote_seps[sc.active_remote_sep_index].seid);
368 
369                 connection = avdtp_get_connection_for_avdtp_cid(cid);
370                 btstack_assert(connection != NULL);
371 
372                 // choose SBC config params
373                 uint8_t sampling_frequency = avdtp_choose_sbc_sampling_frequency(sc.local_stream_endpoint, avdtp_subevent_signaling_media_codec_sbc_capability_get_sampling_frequency_bitmap(packet));
374                 uint8_t channel_mode = avdtp_choose_sbc_channel_mode(sc.local_stream_endpoint, avdtp_subevent_signaling_media_codec_sbc_capability_get_channel_mode_bitmap(packet));
375                 uint8_t block_length = avdtp_choose_sbc_block_length(sc.local_stream_endpoint, avdtp_subevent_signaling_media_codec_sbc_capability_get_block_length_bitmap(packet));
376                 uint8_t subbands = avdtp_choose_sbc_subbands(sc.local_stream_endpoint, avdtp_subevent_signaling_media_codec_sbc_capability_get_subbands_bitmap(packet));
377 
378                 uint8_t allocation_method = avdtp_choose_sbc_allocation_method(sc.local_stream_endpoint, avdtp_subevent_signaling_media_codec_sbc_capability_get_allocation_method_bitmap(packet));
379                 uint8_t max_bitpool_value = avdtp_choose_sbc_max_bitpool_value(sc.local_stream_endpoint, avdtp_subevent_signaling_media_codec_sbc_capability_get_max_bitpool_value(packet));
380                 uint8_t min_bitpool_value = avdtp_choose_sbc_min_bitpool_value(sc.local_stream_endpoint, avdtp_subevent_signaling_media_codec_sbc_capability_get_min_bitpool_value(packet));
381 
382 				// set media configuration
383 				sc.local_stream_endpoint->remote_configuration_bitmap = store_bit16(sc.local_stream_endpoint->remote_configuration_bitmap, AVDTP_MEDIA_CODEC, 1);
384 				sc.local_stream_endpoint->remote_configuration.media_codec.media_type = AVDTP_AUDIO;
385 				sc.local_stream_endpoint->remote_configuration.media_codec.media_codec_type = AVDTP_CODEC_SBC;
386 
387                 // select reserved SBC config buffer
388                 sc.local_stream_endpoint->remote_configuration.media_codec.media_codec_information = sc.local_stream_endpoint->media_codec_sbc_info;
389                 sc.local_stream_endpoint->remote_configuration.media_codec.media_codec_information_len = 4;
390 
391 				// store SBC configuration in reserved field
392                 sc.local_stream_endpoint->remote_configuration.media_codec.media_codec_information[0] = (sampling_frequency << 4) | channel_mode;
393                 sc.local_stream_endpoint->remote_configuration.media_codec.media_codec_information[1] = (block_length << 4) | (subbands << 2) | allocation_method;
394                 sc.local_stream_endpoint->remote_configuration.media_codec.media_codec_information[2] = min_bitpool_value;
395                 sc.local_stream_endpoint->remote_configuration.media_codec.media_codec_information[3] = max_bitpool_value;
396 
397                 // suitable Sink SEP found, configure SEP
398                 sep_found_w2_set_configuration = true;
399                 connection->supported_codecs_bitmap |= (1 << AVDTP_CODEC_SBC);
400             }
401             break;
402 
403         case AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_OTHER_CAPABILITY:
404             log_info("received non SBC codec. not implemented");
405             break;
406 
407         case AVDTP_SUBEVENT_SIGNALING_MEDIA_TRANSPORT_CAPABILITY:
408             log_info("received, but not forwarded: AVDTP_SUBEVENT_SIGNALING_MEDIA_TRANSPORT_CAPABILITY, remote seid 0x%02x", avdtp_subevent_signaling_media_transport_capability_get_remote_seid(packet));
409             break;
410         case AVDTP_SUBEVENT_SIGNALING_REPORTING_CAPABILITY:
411             log_info("received, but not forwarded: AVDTP_SUBEVENT_SIGNALING_REPORTING_CAPABILITY, remote seid 0x%02x", avdtp_subevent_signaling_reporting_capability_get_remote_seid(packet));
412             break;
413         case AVDTP_SUBEVENT_SIGNALING_RECOVERY_CAPABILITY:
414             log_info("received, but not forwarded: AVDTP_SUBEVENT_SIGNALING_RECOVERY_CAPABILITY, remote seid 0x%02x", avdtp_subevent_signaling_recovery_capability_get_remote_seid(packet));
415             break;
416         case AVDTP_SUBEVENT_SIGNALING_CONTENT_PROTECTION_CAPABILITY:
417             log_info("received, but not forwarded: AVDTP_SUBEVENT_SIGNALING_CONTENT_PROTECTION_CAPABILITY, remote seid 0x%02x", avdtp_subevent_signaling_content_protection_capability_get_remote_seid(packet));
418             break;
419         case AVDTP_SUBEVENT_SIGNALING_HEADER_COMPRESSION_CAPABILITY:
420             log_info("received, but not forwarded: AVDTP_SUBEVENT_SIGNALING_HEADER_COMPRESSION_CAPABILITY, remote seid 0x%02x", avdtp_subevent_signaling_header_compression_capability_get_remote_seid(packet));
421             break;
422         case AVDTP_SUBEVENT_SIGNALING_MULTIPLEXING_CAPABILITY:
423             log_info("received, but not forwarded: AVDTP_SUBEVENT_SIGNALING_MULTIPLEXING_CAPABILITY, remote seid 0x%02x", avdtp_subevent_signaling_multiplexing_capability_get_remote_seid(packet));
424             break;
425 
426         case AVDTP_SUBEVENT_SIGNALING_DELAY_REPORTING_CAPABILITY:
427             cid = avdtp_subevent_signaling_delay_reporting_capability_get_avdtp_cid(packet);
428             log_info("received AVDTP_SUBEVENT_SIGNALING_DELAY_REPORTING_CAPABILITY, cid 0x%02x, state %d", cid, a2dp_source_state);
429 
430             if (a2dp_source_cid != cid) break;
431             if (a2dp_source_state != A2DP_GET_CAPABILITIES) break;
432 
433             sc.local_stream_endpoint->remote_configuration_bitmap = store_bit16(sc.local_stream_endpoint->remote_configuration_bitmap, AVDTP_DELAY_REPORTING, 1);
434             a2dp_replace_subevent_id_and_emit_cmd(a2dp_source_packet_handler_user, packet, size, A2DP_SUBEVENT_SIGNALING_DELAY_REPORTING_CAPABILITY);
435             break;
436 
437         case AVDTP_SUBEVENT_SIGNALING_CAPABILITIES_DONE:
438             cid = avdtp_subevent_signaling_capabilities_done_get_avdtp_cid(packet);
439             if (a2dp_source_cid != cid) break;
440             if (a2dp_source_state != A2DP_GET_CAPABILITIES) break;
441 
442             if (sep_found_w2_set_configuration){
443                 a2dp_source_state = A2DP_SET_CONFIGURATION;
444                 sep_found_w2_set_configuration = false;
445                 break;
446             }
447             // endpoint was not suitable, check next one
448             sc.active_remote_sep_index++;
449             if (sc.active_remote_sep_index >= num_remote_seps){
450                 // we didn't find a suitable SBC stream endpoint, sorry.
451                 if (outgoing_active){
452                     outgoing_active = false;
453                     connection = avdtp_get_connection_for_avdtp_cid(cid);
454                     btstack_assert(connection != NULL);
455                     a2dp_source_streaming_emit_connection_failed(connection, sc.local_stream_endpoint->sep.seid, ERROR_CODE_CONNECTION_REJECTED_DUE_TO_NO_SUITABLE_CHANNEL_FOUND);
456                 }
457                 a2dp_discover_seps_with_next_waiting_connection();
458             }
459             break;
460 
461         case AVDTP_SUBEVENT_SIGNALING_DELAY_REPORT:
462             cid = avdtp_subevent_signaling_delay_report_get_avdtp_cid(packet);
463             if (a2dp_source_cid != cid) break;
464             a2dp_replace_subevent_id_and_emit_cmd(a2dp_source_packet_handler_user, packet, size, A2DP_SUBEVENT_SIGNALING_DELAY_REPORT);
465             break;
466 
467         case AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_SBC_CONFIGURATION:
468             cid = avdtp_subevent_signaling_media_codec_sbc_configuration_get_avdtp_cid(packet);
469 
470             if ((a2dp_source_cid == cid) && (a2dp_source_state == A2DP_W4_SET_CONFIGURATION)){
471 				// outgoing: discovery and config of remote sink sep successful, trigger stream open
472 				a2dp_source_state = A2DP_W2_OPEN_STREAM_WITH_SEID;
473             } else {
474 				// incoming: accept cid and wait for stream open
475 				a2dp_source_cid = cid;
476 				a2dp_source_state = A2DP_W4_OPEN_STREAM_WITH_SEID;
477             }
478 
479             // config set: stop timer
480 			a2dp_source_set_config_timer_stop();
481             stream_endpoint_configured = true;
482 
483             sc.sampling_frequency = avdtp_subevent_signaling_media_codec_sbc_configuration_get_sampling_frequency(packet);
484             sc.channel_mode = avdtp_subevent_signaling_media_codec_sbc_configuration_get_channel_mode(packet);
485             sc.block_length = avdtp_subevent_signaling_media_codec_sbc_configuration_get_block_length(packet);
486             sc.subbands = avdtp_subevent_signaling_media_codec_sbc_configuration_get_subbands(packet);
487             sc.allocation_method = avdtp_subevent_signaling_media_codec_sbc_configuration_get_allocation_method(packet);
488             sc.max_bitpool_value = avdtp_subevent_signaling_media_codec_sbc_configuration_get_max_bitpool_value(packet);
489             sc.min_bitpool_value = avdtp_subevent_signaling_media_codec_sbc_configuration_get_min_bitpool_value(packet);
490 
491             log_info("A2DP received SBC Config: sample rate %u, max bitpool %u., remote seid 0x%02x", sc.sampling_frequency, sc.max_bitpool_value, avdtp_subevent_signaling_media_codec_sbc_configuration_get_remote_seid(packet));
492             a2dp_replace_subevent_id_and_emit_cmd(a2dp_source_packet_handler_user, packet, size, A2DP_SUBEVENT_SIGNALING_MEDIA_CODEC_SBC_CONFIGURATION);
493             break;
494 
495         case AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_OTHER_CONFIGURATION:
496             break;
497 
498         case AVDTP_SUBEVENT_STREAMING_CAN_SEND_MEDIA_PACKET_NOW:
499             a2dp_replace_subevent_id_and_emit_cmd(a2dp_source_packet_handler_user, packet, size, A2DP_SUBEVENT_STREAMING_CAN_SEND_MEDIA_PACKET_NOW);
500             break;
501 
502         case AVDTP_SUBEVENT_STREAMING_CONNECTION_ESTABLISHED:
503             cid = avdtp_subevent_streaming_connection_established_get_avdtp_cid(packet);
504             if (a2dp_source_cid != cid) break;
505             if (a2dp_source_state != A2DP_W4_OPEN_STREAM_WITH_SEID) break;
506 
507 			outgoing_active = false;
508             status = avdtp_subevent_streaming_connection_established_get_status(packet);
509             if (status != ERROR_CODE_SUCCESS){
510                 log_info("A2DP source streaming connection could not be established, avdtp_cid 0x%02x, status 0x%02x ---", cid, status);
511                 a2dp_replace_subevent_id_and_emit_cmd(a2dp_source_packet_handler_user, packet, size, A2DP_SUBEVENT_STREAM_ESTABLISHED);
512                 break;
513             }
514 
515             log_info("A2DP source streaming connection established --- avdtp_cid 0x%02x, local seid 0x%02x, remote seid 0x%02x", cid,
516                 avdtp_subevent_streaming_connection_established_get_local_seid(packet),
517                 avdtp_subevent_streaming_connection_established_get_remote_seid(packet));
518             a2dp_source_state = A2DP_STREAMING_OPENED;
519             a2dp_replace_subevent_id_and_emit_cmd(a2dp_source_packet_handler_user, packet, size, A2DP_SUBEVENT_STREAM_ESTABLISHED);
520             break;
521 
522         case AVDTP_SUBEVENT_SIGNALING_ACCEPT:
523             cid = avdtp_subevent_signaling_accept_get_avdtp_cid(packet);
524 
525 			// reset discovery timer while remote is active
526 			if (avdtp_subevent_signaling_accept_get_is_initiator(packet) == 0) {
527 				uint16_t avdtp_cid = (uint16_t)(uintptr_t) btstack_run_loop_get_timer_context(&a2dp_source_set_config_timer);
528 				if ((avdtp_cid == 0) || (avdtp_cid != cid)) break;
529 				log_info("Reset discovery timer");
530 				a2dp_source_set_config_timer_start(avdtp_cid);
531 				break;
532 			}
533 
534             if (a2dp_source_cid != cid) break;
535 
536             signal_identifier = avdtp_subevent_signaling_accept_get_signal_identifier(packet);
537 
538             log_info("A2DP cmd %s accepted, global state %d, cid 0x%02x", avdtp_si2str(signal_identifier), a2dp_source_state, cid);
539 
540             switch (a2dp_source_state){
541                 case A2DP_GET_CAPABILITIES:
542                     remote_seid = remote_seps[sc.active_remote_sep_index].seid;
543                     log_info("A2DP get capabilities for remote seid 0x%02x", remote_seid);
544                     avdtp_source_get_all_capabilities(cid, remote_seid);
545                     return;
546 
547                 case A2DP_SET_CONFIGURATION:
548                     remote_seid = remote_seps[sc.active_remote_sep_index].seid;
549                     log_info("A2DP initiate set configuration locally and wait for response ... local seid 0x%02x, remote seid 0x%02x", avdtp_stream_endpoint_seid(sc.local_stream_endpoint), remote_seid);
550                     a2dp_source_state = A2DP_W4_SET_CONFIGURATION;
551                     avdtp_source_set_configuration(cid, avdtp_stream_endpoint_seid(sc.local_stream_endpoint), remote_seid, sc.local_stream_endpoint->remote_configuration_bitmap, sc.local_stream_endpoint->remote_configuration);
552                     return;
553 
554                 case A2DP_W2_OPEN_STREAM_WITH_SEID:
555                     log_info("A2DP open stream ... local seid 0x%02x, active remote seid 0x%02x", avdtp_stream_endpoint_seid(sc.local_stream_endpoint), sc.local_stream_endpoint->remote_sep.seid);
556                     a2dp_source_state = A2DP_W4_OPEN_STREAM_WITH_SEID;
557                     avdtp_source_open_stream(cid, avdtp_stream_endpoint_seid(sc.local_stream_endpoint), sc.local_stream_endpoint->remote_sep.seid);
558                     break;
559 
560                 case A2DP_W2_RECONFIGURE_WITH_SEID:
561                     log_info("A2DP reconfigured ... local seid 0x%02x, active remote seid 0x%02x", avdtp_stream_endpoint_seid(sc.local_stream_endpoint), sc.local_stream_endpoint->remote_sep.seid);
562                     a2dp_signaling_emit_reconfigured(cid, avdtp_stream_endpoint_seid(sc.local_stream_endpoint), ERROR_CODE_SUCCESS);
563                     a2dp_source_state = A2DP_STREAMING_OPENED;
564                     break;
565 
566                 case A2DP_STREAMING_OPENED:
567                     switch (signal_identifier){
568                         case  AVDTP_SI_START:
569                             a2dp_emit_stream_event(a2dp_source_packet_handler_user, cid, avdtp_stream_endpoint_seid(sc.local_stream_endpoint), A2DP_SUBEVENT_STREAM_STARTED);
570                             break;
571                         case AVDTP_SI_SUSPEND:
572                             a2dp_emit_stream_event(a2dp_source_packet_handler_user, cid, avdtp_stream_endpoint_seid(sc.local_stream_endpoint), A2DP_SUBEVENT_STREAM_SUSPENDED);
573                             break;
574                         case AVDTP_SI_ABORT:
575                         case AVDTP_SI_CLOSE:
576                             a2dp_emit_stream_event(a2dp_source_packet_handler_user, cid, avdtp_stream_endpoint_seid(sc.local_stream_endpoint), A2DP_SUBEVENT_STREAM_STOPPED);
577                             break;
578                         default:
579                             break;
580                     }
581                     break;
582 
583                 default:
584                     break;
585             }
586             break;
587 
588         case AVDTP_SUBEVENT_SIGNALING_REJECT:
589             cid = avdtp_subevent_signaling_reject_get_avdtp_cid(packet);
590             if (a2dp_source_cid != cid) break;
591             if (avdtp_subevent_signaling_reject_get_is_initiator(packet) == 0) break;
592 
593             a2dp_source_state = A2DP_CONNECTED;
594             a2dp_replace_subevent_id_and_emit_cmd(a2dp_source_packet_handler_user, packet, size, A2DP_SUBEVENT_COMMAND_REJECTED);
595             break;
596 
597         case AVDTP_SUBEVENT_SIGNALING_GENERAL_REJECT:
598             cid = avdtp_subevent_signaling_general_reject_get_avdtp_cid(packet);
599             if (a2dp_source_cid != cid) break;
600             if (avdtp_subevent_signaling_general_reject_get_is_initiator(packet) == 0) break;
601 
602             a2dp_source_state = A2DP_CONNECTED;
603             a2dp_replace_subevent_id_and_emit_cmd(a2dp_source_packet_handler_user, packet, size, A2DP_SUBEVENT_COMMAND_REJECTED);
604             break;
605 
606         case AVDTP_SUBEVENT_STREAMING_CONNECTION_RELEASED:
607             cid = avdtp_subevent_streaming_connection_released_get_avdtp_cid(packet);
608             if (a2dp_source_cid != cid) break;
609 
610             a2dp_source_state = A2DP_CONFIGURED;
611             a2dp_replace_subevent_id_and_emit_cmd(a2dp_source_packet_handler_user, packet, size, A2DP_SUBEVENT_STREAM_RELEASED);
612             break;
613 
614         case AVDTP_SUBEVENT_SIGNALING_CONNECTION_RELEASED:
615             cid = avdtp_subevent_signaling_connection_released_get_avdtp_cid(packet);
616             // connect/release are passed on to app
617             if (a2dp_source_cid == cid){
618                 stream_endpoint_configured = false;
619                 a2dp_source_state = A2DP_IDLE;
620                 a2dp_source_cid = 0;
621             }
622             a2dp_replace_subevent_id_and_emit_cmd(a2dp_source_packet_handler_user, packet, size, A2DP_SUBEVENT_SIGNALING_CONNECTION_RELEASED);
623             break;
624 
625         default:
626             break;
627     }
628 }
629 void a2dp_source_register_packet_handler(btstack_packet_handler_t callback){
630     btstack_assert(callback != NULL);
631 
632     avdtp_source_register_packet_handler(&a2dp_source_packet_handler_internal);
633     a2dp_source_packet_handler_user = callback;
634 }
635 
636 void a2dp_source_init(void){
637     avdtp_source_init();
638 }
639 
640 avdtp_stream_endpoint_t * a2dp_source_create_stream_endpoint(avdtp_media_type_t media_type, avdtp_media_codec_type_t media_codec_type,
641 															 uint8_t * codec_capabilities, uint16_t codec_capabilities_len,
642 															 uint8_t * codec_configuration, uint16_t codec_configuration_len){
643     avdtp_stream_endpoint_t * local_stream_endpoint = avdtp_source_create_stream_endpoint(AVDTP_SOURCE, media_type);
644     if (!local_stream_endpoint){
645         return NULL;
646     }
647     avdtp_source_register_media_transport_category(avdtp_stream_endpoint_seid(local_stream_endpoint));
648     avdtp_source_register_media_codec_category(avdtp_stream_endpoint_seid(local_stream_endpoint), media_type, media_codec_type,
649         codec_capabilities, codec_capabilities_len);
650 	avdtp_source_register_delay_reporting_category(avdtp_stream_endpoint_seid(local_stream_endpoint));
651 
652 	// store user codec configuration buffer
653 	local_stream_endpoint->media_codec_configuration_info = codec_configuration;
654 	local_stream_endpoint->media_codec_configuration_len  = codec_configuration_len;
655 
656     sc.local_stream_endpoint = local_stream_endpoint;
657     return local_stream_endpoint;
658 }
659 
660 void a2dp_source_finalize_stream_endpoint(avdtp_stream_endpoint_t * stream_endpoint){
661     avdtp_source_finalize_stream_endpoint(stream_endpoint);
662 }
663 
664 uint8_t a2dp_source_establish_stream(bd_addr_t remote_addr, uint8_t loc_seid, uint16_t * avdtp_cid){
665     if (outgoing_active || stream_endpoint_configured) {
666         return ERROR_CODE_COMMAND_DISALLOWED;
667     }
668 
669     sc.local_stream_endpoint = avdtp_get_stream_endpoint_for_seid(loc_seid);
670     if (!sc.local_stream_endpoint){
671         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
672     }
673 
674     uint16_t outgoing_cid;
675 
676     outgoing_active = true;
677     uint8_t status = avdtp_source_connect(remote_addr, &outgoing_cid);
678     if (status != ERROR_CODE_SUCCESS) {
679         // if there's already a connection for for remote addr, avdtp_source_connect fails,
680         // but the stream will get set-up nevertheless
681         outgoing_active = false;
682         return status;
683     }
684 
685     // stop sep discovery for other
686     if (a2dp_source_state != A2DP_IDLE){
687         avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(a2dp_source_cid);
688         if (connection != NULL){
689             // sdp discovery has started: post-pone action, reserve sep discovery mechanism
690             connection->a2dp_source_discover_seps = true;
691         }
692     }
693 
694     // setup state
695     a2dp_source_state = A2DP_W4_CONNECTED;
696     a2dp_source_cid   = outgoing_cid;
697     *avdtp_cid = outgoing_cid;
698 
699     return ERROR_CODE_SUCCESS;
700 }
701 
702 uint8_t a2dp_source_disconnect(uint16_t avdtp_cid){
703     return avdtp_disconnect(avdtp_cid);
704 }
705 
706 uint8_t a2dp_source_reconfigure_stream_sampling_frequency(uint16_t avdtp_cid, uint32_t sampling_frequency){
707     btstack_assert(sc.local_stream_endpoint != NULL);
708 
709     if (a2dp_source_cid != avdtp_cid){
710         return ERROR_CODE_COMMAND_DISALLOWED;
711     }
712 
713     avdtp_connection_t * connection = avdtp_get_connection_for_avdtp_cid(avdtp_cid);
714     if (connection == NULL){
715         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
716     }
717 
718     if (a2dp_source_state != A2DP_STREAMING_OPENED) {
719         return ERROR_CODE_COMMAND_DISALLOWED;
720     }
721 
722     log_info("Reconfigure avdtp_cid 0x%02x", avdtp_cid);
723 
724     (void)memcpy(sc.local_stream_endpoint->media_codec_sbc_info,
725                  sc.local_stream_endpoint->remote_sep.configuration.media_codec.media_codec_information,
726                  4);
727 
728     // update sampling frequency
729     uint8_t config = sc.local_stream_endpoint->media_codec_sbc_info[0] & 0x0f;
730     switch (sampling_frequency){
731         case 48000:
732             config |= (AVDTP_SBC_48000 << 4);
733             break;
734         case 44100:
735             config |= (AVDTP_SBC_44100 << 4);
736             break;
737         case 32000:
738             config |= (AVDTP_SBC_32000 << 4);
739             break;
740         case 16000:
741             config |= (AVDTP_SBC_16000 << 4);
742             break;
743         default:
744             log_error("Unsupported sampling frequency %u", sampling_frequency);
745             return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
746     }
747     sc.local_stream_endpoint->media_codec_sbc_info[0] = config;
748 
749     avdtp_capabilities_t new_configuration;
750     new_configuration.media_codec.media_type = AVDTP_AUDIO;
751     new_configuration.media_codec.media_codec_type = AVDTP_CODEC_SBC;
752     new_configuration.media_codec.media_codec_information_len = 4;
753     new_configuration.media_codec.media_codec_information = sc.local_stream_endpoint->media_codec_sbc_info;
754 
755     // start reconfigure
756     a2dp_source_state = A2DP_W2_RECONFIGURE_WITH_SEID;
757 
758     return avdtp_source_reconfigure(
759         avdtp_cid,
760         avdtp_stream_endpoint_seid(sc.local_stream_endpoint),
761         sc.local_stream_endpoint->remote_sep.seid,
762         1 << AVDTP_MEDIA_CODEC,
763         new_configuration
764     );
765 }
766 
767 uint8_t a2dp_source_start_stream(uint16_t avdtp_cid, uint8_t local_seid){
768     return avdtp_start_stream(avdtp_cid, local_seid);
769 }
770 
771 uint8_t a2dp_source_pause_stream(uint16_t avdtp_cid, uint8_t local_seid){
772     return avdtp_suspend_stream(avdtp_cid, local_seid);
773 }
774 
775 void a2dp_source_stream_endpoint_request_can_send_now(uint16_t avdtp_cid, uint8_t local_seid){
776     avdtp_source_stream_endpoint_request_can_send_now(avdtp_cid, local_seid);
777 }
778 
779 int a2dp_max_media_payload_size(uint16_t avdtp_cid, uint8_t local_seid){
780     return avdtp_max_media_payload_size(avdtp_cid, local_seid);
781 }
782 
783 int a2dp_source_stream_send_media_payload(uint16_t avdtp_cid, uint8_t local_seid, uint8_t * storage, int num_bytes_to_copy, uint8_t num_frames, uint8_t marker){
784     return avdtp_source_stream_send_media_payload(avdtp_cid, local_seid, storage, num_bytes_to_copy, num_frames, marker);
785 }
786