xref: /btstack/src/classic/a2dp_source.c (revision 4a76e901eb996c28c0a2765419f7d0923970af50)
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 #define __BTSTACK_FILE__ "a2dp_source.c"
40 
41 #include <stdint.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 
46 #include "btstack.h"
47 #include "avdtp.h"
48 #include "avdtp_util.h"
49 #include "avdtp_source.h"
50 #include "a2dp_source.h"
51 
52 #define AVDTP_MEDIA_PAYLOAD_HEADER_SIZE 12
53 
54 static const char * default_a2dp_source_service_name = "BTstack A2DP Source Service";
55 static const char * default_a2dp_source_service_provider_name = "BTstack A2DP Source Service Provider";
56 static avdtp_context_t a2dp_source_context;
57 
58 static a2dp_state_t app_state = A2DP_IDLE;
59 static avdtp_stream_endpoint_context_t sc;
60 static uint16_t avdtp_cid = 0;
61 static int next_remote_sep_index_to_query = 0;
62 
63 static void packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
64 
65 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){
66     uint8_t* attribute;
67     de_create_sequence(service);
68 
69     // 0x0000 "Service Record Handle"
70     de_add_number(service, DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_SERVICE_RECORD_HANDLE);
71     de_add_number(service, DE_UINT, DE_SIZE_32, service_record_handle);
72 
73     // 0x0001 "Service Class ID List"
74     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_SERVICE_CLASS_ID_LIST);
75     attribute = de_push_sequence(service);
76     {
77         de_add_number(attribute, DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_AUDIO_SOURCE);
78     }
79     de_pop_sequence(service, attribute);
80 
81     // 0x0004 "Protocol Descriptor List"
82     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_PROTOCOL_DESCRIPTOR_LIST);
83     attribute = de_push_sequence(service);
84     {
85         uint8_t* l2cpProtocol = de_push_sequence(attribute);
86         {
87             de_add_number(l2cpProtocol,  DE_UUID, DE_SIZE_16, BLUETOOTH_PROTOCOL_L2CAP);
88             de_add_number(l2cpProtocol,  DE_UINT, DE_SIZE_16, BLUETOOTH_PROTOCOL_AVDTP);
89         }
90         de_pop_sequence(attribute, l2cpProtocol);
91 
92         uint8_t* avProtocol = de_push_sequence(attribute);
93         {
94             de_add_number(avProtocol,  DE_UUID, DE_SIZE_16, BLUETOOTH_PROTOCOL_AVDTP);  // avProtocol_service
95             de_add_number(avProtocol,  DE_UINT, DE_SIZE_16,  0x0103);  // version
96         }
97         de_pop_sequence(attribute, avProtocol);
98     }
99     de_pop_sequence(service, attribute);
100 
101     // 0x0005 "Public Browse Group"
102     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_BROWSE_GROUP_LIST); // public browse group
103     attribute = de_push_sequence(service);
104     {
105         de_add_number(attribute,  DE_UUID, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_PUBLIC_BROWSE_ROOT);
106     }
107     de_pop_sequence(service, attribute);
108 
109     // 0x0009 "Bluetooth Profile Descriptor List"
110     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_BLUETOOTH_PROFILE_DESCRIPTOR_LIST);
111     attribute = de_push_sequence(service);
112     {
113         uint8_t *a2dProfile = de_push_sequence(attribute);
114         {
115             de_add_number(a2dProfile,  DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_ADVANCED_AUDIO_DISTRIBUTION);
116             de_add_number(a2dProfile,  DE_UINT, DE_SIZE_16, 0x0103);
117         }
118         de_pop_sequence(attribute, a2dProfile);
119     }
120     de_pop_sequence(service, attribute);
121 
122 
123     // 0x0100 "Service Name"
124     de_add_number(service,  DE_UINT, DE_SIZE_16, 0x0100);
125     if (service_name){
126         de_add_data(service,  DE_STRING, strlen(service_name), (uint8_t *) service_name);
127     } else {
128         de_add_data(service,  DE_STRING, strlen(default_a2dp_source_service_name), (uint8_t *) default_a2dp_source_service_name);
129     }
130 
131     // 0x0100 "Provider Name"
132     de_add_number(service,  DE_UINT, DE_SIZE_16, 0x0102);
133     if (service_provider_name){
134         de_add_data(service,  DE_STRING, strlen(service_provider_name), (uint8_t *) service_provider_name);
135     } else {
136         de_add_data(service,  DE_STRING, strlen(default_a2dp_source_service_provider_name), (uint8_t *) default_a2dp_source_service_provider_name);
137     }
138 
139     // 0x0311 "Supported Features"
140     de_add_number(service, DE_UINT, DE_SIZE_16, 0x0311);
141     de_add_number(service, DE_UINT, DE_SIZE_16, supported_features);
142 }
143 
144 static void a2dp_streaming_emit_connection_established(btstack_packet_handler_t callback, uint16_t cid, uint8_t local_seid, uint8_t remote_seid, uint8_t status){
145     if (!callback) return;
146     uint8_t event[8];
147     int pos = 0;
148     event[pos++] = HCI_EVENT_A2DP_META;
149     event[pos++] = sizeof(event) - 2;
150     event[pos++] = A2DP_SUBEVENT_STREAM_ESTABLISHED;
151     little_endian_store_16(event, pos, cid);
152     pos += 2;
153     event[pos++] = local_seid;
154     event[pos++] = remote_seid;
155     event[pos++] = status;
156     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
157 }
158 
159 static void a2dp_streaming_emit_can_send_media_packet_now(btstack_packet_handler_t callback, uint16_t cid, uint8_t seid){
160     if (!callback) return;
161     uint8_t event[8];
162     int pos = 0;
163     event[pos++] = HCI_EVENT_A2DP_META;
164     event[pos++] = sizeof(event) - 2;
165     event[pos++] = A2DP_SUBEVENT_STREAMING_CAN_SEND_MEDIA_PACKET_NOW;
166     little_endian_store_16(event, pos, cid);
167     pos += 2;
168     event[pos++] = seid;
169     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
170 }
171 
172 static void packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
173     UNUSED(channel);
174     UNUSED(size);
175 
176     uint8_t signal_identifier;
177     uint8_t status;
178     avdtp_sep_t sep;
179     uint8_t int_seid;
180     uint8_t acp_seid;
181 
182     switch (packet_type) {
183 
184         case HCI_EVENT_PACKET:
185             switch (hci_event_packet_get_type(packet)) {
186                 case HCI_EVENT_DISCONNECTION_COMPLETE:
187                     // connection closed -> quit test app
188                     log_info("\n --- a2dp source --- HCI_EVENT_DISCONNECTION_COMPLETE ---");
189                     break;
190                 case HCI_EVENT_AVDTP_META:
191                     switch (packet[2]){
192                         case AVDTP_SUBEVENT_SIGNALING_CONNECTION_ESTABLISHED:
193                             avdtp_cid = avdtp_subevent_signaling_connection_established_get_avdtp_cid(packet);
194                             status = avdtp_subevent_signaling_connection_established_get_status(packet);
195                             if (status != 0){
196                                 log_info(" --- a2dp source --- AVDTP_SUBEVENT_SIGNALING_CONNECTION could not be established, status %d ---", status);
197                                 break;
198                             }
199                             sc.active_remote_sep = NULL;
200                             next_remote_sep_index_to_query = 0;
201                             app_state = A2DP_W2_DISCOVER_SEPS;
202                             log_info(" --- a2dp source --- AVDTP_SUBEVENT_SIGNALING_CONNECTION_ESTABLISHED, avdtp cid 0x%02x ---", avdtp_cid);
203                             avdtp_source_discover_stream_endpoints(avdtp_cid);
204                             break;
205 
206                         case AVDTP_SUBEVENT_STREAMING_CONNECTION_ESTABLISHED:
207                             status = avdtp_subevent_streaming_connection_established_get_status(packet);
208                             avdtp_cid = avdtp_subevent_streaming_connection_established_get_avdtp_cid(packet);
209                             int_seid = avdtp_subevent_streaming_connection_established_get_int_seid(packet);
210                             acp_seid = avdtp_subevent_streaming_connection_established_get_acp_seid(packet);
211 
212                             if (status != 0){
213                                 log_info(" --- a2dp source --- AVDTP_SUBEVENT_STREAMING_CONNECTION could not be established, status %d ---", status);
214                                 break;
215                             }
216                             app_state = A2DP_STREAMING_OPENED;
217                             a2dp_streaming_emit_connection_established(a2dp_source_context.a2dp_callback, avdtp_cid, int_seid, acp_seid, 0);
218                             log_info(" --- a2dp source --- AVDTP_SUBEVENT_STREAMING_CONNECTION_ESTABLISHED --- avdtp_cid 0x%02x, local seid %d, remote seid %d", avdtp_cid, int_seid, acp_seid);
219                             break;
220 
221                         case AVDTP_SUBEVENT_SIGNALING_SEP_FOUND:
222                             if (app_state != A2DP_W2_DISCOVER_SEPS) return;
223                             sep.seid = avdtp_subevent_signaling_sep_found_get_seid(packet);
224                             sep.in_use = avdtp_subevent_signaling_sep_found_get_in_use(packet);
225                             sep.media_type = (avdtp_media_type_t) avdtp_subevent_signaling_sep_found_get_media_type(packet);
226                             sep.type = (avdtp_sep_type_t) avdtp_subevent_signaling_sep_found_get_sep_type(packet);
227                             log_info(" --- a2dp source --- Found sep: seid %u, in_use %d, media type %d, sep type %d (1-SNK)", sep.seid, sep.in_use, sep.media_type, sep.type);
228                             break;
229 
230                         case AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_SBC_CAPABILITY:{
231                             if (!sc.local_stream_endpoint) return;
232                             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));
233                             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));
234                             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));
235                             uint8_t subbands = avdtp_choose_sbc_subbands(sc.local_stream_endpoint, avdtp_subevent_signaling_media_codec_sbc_capability_get_subbands_bitmap(packet));
236 
237                             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));
238                             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));
239                             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));
240 
241                             sc.local_stream_endpoint->remote_configuration.media_codec.media_codec_information[0] = (sampling_frequency << 4) | channel_mode;
242                             sc.local_stream_endpoint->remote_configuration.media_codec.media_codec_information[1] = (block_length << 4) | (subbands << 2) | allocation_method;
243                             sc.local_stream_endpoint->remote_configuration.media_codec.media_codec_information[2] = min_bitpool_value;
244                             sc.local_stream_endpoint->remote_configuration.media_codec.media_codec_information[3] = max_bitpool_value;
245 
246                             sc.local_stream_endpoint->remote_configuration_bitmap = store_bit16(sc.local_stream_endpoint->remote_configuration_bitmap, AVDTP_MEDIA_CODEC, 1);
247                             sc.local_stream_endpoint->remote_configuration.media_codec.media_type = AVDTP_AUDIO;
248                             sc.local_stream_endpoint->remote_configuration.media_codec.media_codec_type = AVDTP_CODEC_SBC;
249 
250                             app_state = A2DP_W2_SET_CONFIGURATION;
251                             break;
252                         }
253                         case AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_OTHER_CAPABILITY:
254                             log_info(" --- a2dp source ---  received non SBC codec. not implemented");
255                             break;
256 
257                         case AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_SBC_CONFIGURATION:{
258                             sc.sampling_frequency = avdtp_subevent_signaling_media_codec_sbc_configuration_get_sampling_frequency(packet);
259                             sc.block_length = avdtp_subevent_signaling_media_codec_sbc_configuration_get_block_length(packet);
260                             sc.subbands = avdtp_subevent_signaling_media_codec_sbc_configuration_get_subbands(packet);
261                             sc.allocation_method = avdtp_subevent_signaling_media_codec_sbc_configuration_get_allocation_method(packet) - 1;
262                             sc.max_bitpool_value = avdtp_subevent_signaling_media_codec_sbc_configuration_get_max_bitpool_value(packet);
263                             // TODO: deal with reconfigure: avdtp_subevent_signaling_media_codec_sbc_configuration_get_reconfigure(packet);
264                             break;
265                         }
266                         case AVDTP_SUBEVENT_STREAMING_CAN_SEND_MEDIA_PACKET_NOW:
267                             a2dp_streaming_emit_can_send_media_packet_now(a2dp_source_context.a2dp_callback, avdtp_cid, 0);
268                             break;
269 
270                         case AVDTP_SUBEVENT_SIGNALING_ACCEPT:
271                             signal_identifier = avdtp_subevent_signaling_accept_get_signal_identifier(packet);
272                             log_info(" --- a2dp source ---  Accepted %d", signal_identifier);
273 
274                             switch (app_state){
275                                 case A2DP_W2_DISCOVER_SEPS:
276                                     app_state = A2DP_W2_GET_ALL_CAPABILITIES;
277                                     sc.active_remote_sep = avdtp_source_remote_sep(avdtp_cid, next_remote_sep_index_to_query++);
278                                     log_info(" --- a2dp source ---  Query get caps for seid %d", sc.active_remote_sep->seid);
279                                     avdtp_source_get_capabilities(avdtp_cid, sc.active_remote_sep->seid);
280                                     break;
281                                 case A2DP_W2_GET_CAPABILITIES:
282                                 case A2DP_W2_GET_ALL_CAPABILITIES:
283                                     if (next_remote_sep_index_to_query < avdtp_source_remote_seps_num(avdtp_cid)){
284                                         sc.active_remote_sep = avdtp_source_remote_sep(avdtp_cid, next_remote_sep_index_to_query++);
285                                         log_info(" --- a2dp source ---  Query get caps for seid %d", sc.active_remote_sep->seid);
286                                         avdtp_source_get_capabilities(avdtp_cid, sc.active_remote_sep->seid);
287                                     } else {
288                                         log_info(" --- a2dp source ---  No more remote seps found");
289                                         app_state = A2DP_IDLE;
290                                     }
291                                     break;
292                                 case A2DP_W2_SET_CONFIGURATION:{
293                                     if (!sc.local_stream_endpoint) return;
294                                     app_state = A2DP_W2_GET_CONFIGURATION;
295                                     avdtp_source_set_configuration(avdtp_cid, avdtp_stream_endpoint_seid(sc.local_stream_endpoint), sc.active_remote_sep->seid, sc.local_stream_endpoint->remote_configuration_bitmap, sc.local_stream_endpoint->remote_configuration);
296                                     break;
297                                 }
298                                 case A2DP_W2_GET_CONFIGURATION:
299                                     app_state = A2DP_W2_OPEN_STREAM_WITH_SEID;
300                                     avdtp_source_get_configuration(avdtp_cid, sc.active_remote_sep->seid);
301                                     break;
302                                 case A2DP_W2_OPEN_STREAM_WITH_SEID:{
303                                     app_state = A2DP_W4_OPEN_STREAM_WITH_SEID;
304                                     btstack_sbc_encoder_init(&sc.sbc_encoder_state, SBC_MODE_STANDARD,
305                                         sc.block_length, sc.subbands,
306                                         sc.allocation_method, sc.sampling_frequency,
307                                         sc.max_bitpool_value);
308                                     avdtp_source_open_stream(avdtp_cid, avdtp_stream_endpoint_seid(sc.local_stream_endpoint), sc.active_remote_sep->seid);
309                                     break;
310                                 }
311                                 case A2DP_STREAMING_OPENED:
312                                     if (!a2dp_source_context.a2dp_callback) return;
313                                     switch (signal_identifier){
314                                         case  AVDTP_SI_START:{
315                                             uint8_t event[6];
316                                             int pos = 0;
317                                             event[pos++] = HCI_EVENT_A2DP_META;
318                                             event[pos++] = sizeof(event) - 2;
319                                             event[pos++] = A2DP_SUBEVENT_STREAM_STARTED;
320                                             little_endian_store_16(event, pos, avdtp_cid);
321                                             pos += 2;
322                                             event[pos++] = avdtp_stream_endpoint_seid(sc.local_stream_endpoint);
323                                             (*a2dp_source_context.a2dp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
324                                             break;
325                                         }
326                                         case AVDTP_SI_SUSPEND:{
327                                             uint8_t event[6];
328                                             int pos = 0;
329                                             event[pos++] = HCI_EVENT_A2DP_META;
330                                             event[pos++] = sizeof(event) - 2;
331                                             event[pos++] = A2DP_SUBEVENT_STREAM_SUSPENDED;
332                                             little_endian_store_16(event, pos, avdtp_cid);
333                                             pos += 2;
334                                             event[pos++] = avdtp_stream_endpoint_seid(sc.local_stream_endpoint);
335                                             (*a2dp_source_context.a2dp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
336                                             break;
337                                         }
338                                         case AVDTP_SI_ABORT:
339                                         case AVDTP_SI_CLOSE:{
340                                             uint8_t event[6];
341                                             int pos = 0;
342                                             event[pos++] = HCI_EVENT_A2DP_META;
343                                             event[pos++] = sizeof(event) - 2;
344                                             event[pos++] = A2DP_SUBEVENT_STREAM_RELEASED;
345                                             little_endian_store_16(event, pos, avdtp_cid);
346                                             pos += 2;
347                                             log_info("send A2DP_SUBEVENT_STREAM_RELEASED to app");
348                                             event[pos++] = avdtp_stream_endpoint_seid(sc.local_stream_endpoint);
349                                             (*a2dp_source_context.a2dp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
350                                             break;
351                                         }
352                                         default:
353                                             break;
354                                     }
355                                     break;
356                                 default:
357                                     app_state = A2DP_IDLE;
358                                     break;
359                             }
360 
361                             break;
362                         case AVDTP_SUBEVENT_SIGNALING_REJECT:
363                             app_state = A2DP_IDLE;
364                             signal_identifier = avdtp_subevent_signaling_reject_get_signal_identifier(packet);
365                             log_info(" --- a2dp source ---  Rejected %d", signal_identifier);
366                             break;
367                         case AVDTP_SUBEVENT_SIGNALING_GENERAL_REJECT:
368                             app_state = A2DP_IDLE;
369                             signal_identifier = avdtp_subevent_signaling_general_reject_get_signal_identifier(packet);
370                             log_info(" --- a2dp source ---  Rejected %d", signal_identifier);
371                             break;
372                         default:
373                             app_state = A2DP_IDLE;
374                             log_info(" --- a2dp source ---  not implemented");
375                             break;
376                     }
377                     break;
378                 default:
379                     break;
380             }
381             break;
382         default:
383             // other packet type
384             break;
385     }
386 }
387 void a2dp_source_register_packet_handler(btstack_packet_handler_t callback){
388     if (callback == NULL){
389         log_error("a2dp_source_register_packet_handler called with NULL callback");
390         return;
391     }
392     avdtp_source_register_packet_handler(&packet_handler);
393     a2dp_source_context.a2dp_callback = callback;
394 }
395 
396 void a2dp_source_init(void){
397     avdtp_source_init(&a2dp_source_context);
398     l2cap_register_service(&packet_handler, BLUETOOTH_PROTOCOL_AVDTP, 0xffff, LEVEL_0);
399 }
400 
401 uint8_t a2dp_source_create_stream_endpoint(avdtp_media_type_t media_type, avdtp_media_codec_type_t media_codec_type,
402     uint8_t * codec_capabilities, uint16_t codec_capabilities_len,
403     uint8_t * media_codec_info, uint16_t media_codec_info_len){
404     avdtp_stream_endpoint_t * local_stream_endpoint = avdtp_source_create_stream_endpoint(AVDTP_SOURCE, media_type);
405     avdtp_source_register_media_transport_category(avdtp_stream_endpoint_seid(local_stream_endpoint));
406     avdtp_source_register_media_codec_category(avdtp_stream_endpoint_seid(local_stream_endpoint), media_type, media_codec_type,
407         codec_capabilities, codec_capabilities_len);
408     local_stream_endpoint->remote_configuration.media_codec.media_codec_information     = media_codec_info;
409     local_stream_endpoint->remote_configuration.media_codec.media_codec_information_len = media_codec_info_len;
410 
411     return local_stream_endpoint->sep.seid;
412 }
413 
414 void a2dp_source_establish_stream(bd_addr_t bd_addr, uint8_t local_seid){
415     sc.local_stream_endpoint = avdtp_stream_endpoint_for_seid(local_seid, &a2dp_source_context);
416     if (!sc.local_stream_endpoint){
417         log_error(" no local_stream_endpoint for seid %d", local_seid);
418         return;
419     }
420     avdtp_source_connect(bd_addr);
421 }
422 
423 void a2dp_source_disconnect(uint16_t local_seid){
424     avdtp_disconnect(local_seid, &a2dp_source_context);
425 }
426 
427 void a2dp_source_start_stream(uint8_t int_seid){
428     avdtp_start_stream(int_seid, &a2dp_source_context);
429 }
430 
431 void a2dp_source_release_stream(uint8_t int_seid){
432     avdtp_stop_stream(int_seid, &a2dp_source_context);
433 }
434 
435 void a2dp_source_pause_stream(uint8_t int_seid){
436     avdtp_suspend_stream(int_seid, &a2dp_source_context);
437 }
438 
439 uint8_t a2dp_source_stream_endpoint_ready(uint8_t local_seid){
440     avdtp_stream_endpoint_t * stream_endpoint = avdtp_stream_endpoint_for_seid(local_seid, &a2dp_source_context);
441     if (!stream_endpoint) {
442         log_error("No stream_endpoint with seid %d", local_seid);
443         return 0;
444     }
445     return (stream_endpoint->state == AVDTP_STREAM_ENDPOINT_STREAMING);
446 }
447 
448 
449 static void a2dp_source_setup_media_header(uint8_t * media_packet, int size, int *offset, uint8_t marker, uint16_t sequence_number){
450     if (size < AVDTP_MEDIA_PAYLOAD_HEADER_SIZE){
451         log_error("small outgoing buffer");
452         return;
453     }
454 
455     uint8_t  rtp_version = 2;
456     uint8_t  padding = 0;
457     uint8_t  extension = 0;
458     uint8_t  csrc_count = 0;
459     uint8_t  payload_type = 0x60;
460     // uint16_t sequence_number = stream_endpoint->sequence_number;
461     uint32_t timestamp = btstack_run_loop_get_time_ms();
462     uint32_t ssrc = 0x11223344;
463 
464     // rtp header (min size 12B)
465     int pos = 0;
466     // int mtu = l2cap_get_remote_mtu_for_local_cid(stream_endpoint->l2cap_media_cid);
467 
468     media_packet[pos++] = (rtp_version << 6) | (padding << 5) | (extension << 4) | csrc_count;
469     media_packet[pos++] = (marker << 1) | payload_type;
470     big_endian_store_16(media_packet, pos, sequence_number);
471     pos += 2;
472     big_endian_store_32(media_packet, pos, timestamp);
473     pos += 4;
474     big_endian_store_32(media_packet, pos, ssrc); // only used for multicast
475     pos += 4;
476     *offset = pos;
477 }
478 
479 void a2dp_source_stream_endpoint_request_can_send_now(uint8_t local_seid){
480     avdtp_stream_endpoint_t * stream_endpoint = avdtp_stream_endpoint_for_seid(local_seid, &a2dp_source_context);
481     if (!stream_endpoint) {
482         log_error("no stream_endpoint for seid %d", local_seid);
483         return;
484     }
485     stream_endpoint->send_stream = 1;
486     avdtp_request_can_send_now_initiator(stream_endpoint->connection, stream_endpoint->l2cap_media_cid);
487 }
488 
489 int a2dp_max_media_payload_size(uint8_t int_seid){
490     avdtp_stream_endpoint_t * stream_endpoint = avdtp_stream_endpoint_for_seid(int_seid, &a2dp_source_context);
491     if (!stream_endpoint) {
492         log_error("no stream_endpoint found for seid %d", int_seid);
493         return 0;
494     }
495     if (stream_endpoint->l2cap_media_cid == 0){
496         log_error("no media cid found for seid %d", int_seid);
497         return 0;
498     }
499     return l2cap_get_remote_mtu_for_local_cid(stream_endpoint->l2cap_media_cid) - AVDTP_MEDIA_PAYLOAD_HEADER_SIZE;
500 }
501 
502 static void a2dp_source_copy_media_payload(uint8_t * media_packet, int size, int * offset, uint8_t * storage, int num_bytes_to_copy, uint8_t num_frames){
503     if (size < num_bytes_to_copy + 1){
504         log_error("small outgoing buffer: buffer size %u, but need %u", size, num_bytes_to_copy + 1);
505         return;
506     }
507 
508     int pos = *offset;
509     media_packet[pos++] = num_frames; // (fragmentation << 7) | (starting_packet << 6) | (last_packet << 5) | num_frames;
510     memcpy(media_packet + pos, storage, num_bytes_to_copy);
511     pos += num_bytes_to_copy;
512     *offset = pos;
513 }
514 
515 int a2dp_source_stream_send_media_payload(uint8_t int_seid, uint8_t * storage, int num_bytes_to_copy, uint8_t num_frames, uint8_t marker){
516     avdtp_stream_endpoint_t * stream_endpoint = avdtp_stream_endpoint_for_seid(int_seid, &a2dp_source_context);
517     if (!stream_endpoint) {
518         log_error("no stream_endpoint found for seid %d", int_seid);
519         return 0;
520     }
521 
522     if (stream_endpoint->l2cap_media_cid == 0){
523         log_error("no media cid found for seid %d", int_seid);
524         return 0;
525     }
526 
527     int size = l2cap_get_remote_mtu_for_local_cid(stream_endpoint->l2cap_media_cid);
528     int offset = 0;
529 
530     l2cap_reserve_packet_buffer();
531     uint8_t * media_packet = l2cap_get_outgoing_buffer();
532     //int size = l2cap_get_remote_mtu_for_local_cid(stream_endpoint->l2cap_media_cid);
533     a2dp_source_setup_media_header(media_packet, size, &offset, marker, stream_endpoint->sequence_number);
534     a2dp_source_copy_media_payload(media_packet, size, &offset, storage, num_bytes_to_copy, num_frames);
535     stream_endpoint->sequence_number++;
536     l2cap_send_prepared(stream_endpoint->l2cap_media_cid, offset);
537     return size;
538 }
539