xref: /btstack/src/classic/a2dp_source.c (revision 4567cc17d5bb3f07171c4043dde62a5fb0bf4645)
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 int next_remote_sep_index_to_query = 0;
61 
62 static void packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
63 
64 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){
65     uint8_t* attribute;
66     de_create_sequence(service);
67 
68     // 0x0000 "Service Record Handle"
69     de_add_number(service, DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_SERVICE_RECORD_HANDLE);
70     de_add_number(service, DE_UINT, DE_SIZE_32, service_record_handle);
71 
72     // 0x0001 "Service Class ID List"
73     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_SERVICE_CLASS_ID_LIST);
74     attribute = de_push_sequence(service);
75     {
76         de_add_number(attribute, DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_AUDIO_SOURCE);
77     }
78     de_pop_sequence(service, attribute);
79 
80     // 0x0004 "Protocol Descriptor List"
81     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_PROTOCOL_DESCRIPTOR_LIST);
82     attribute = de_push_sequence(service);
83     {
84         uint8_t* l2cpProtocol = de_push_sequence(attribute);
85         {
86             de_add_number(l2cpProtocol,  DE_UUID, DE_SIZE_16, BLUETOOTH_PROTOCOL_L2CAP);
87             de_add_number(l2cpProtocol,  DE_UINT, DE_SIZE_16, BLUETOOTH_PROTOCOL_AVDTP);
88         }
89         de_pop_sequence(attribute, l2cpProtocol);
90 
91         uint8_t* avProtocol = de_push_sequence(attribute);
92         {
93             de_add_number(avProtocol,  DE_UUID, DE_SIZE_16, BLUETOOTH_PROTOCOL_AVDTP);  // avProtocol_service
94             de_add_number(avProtocol,  DE_UINT, DE_SIZE_16,  0x0103);  // version
95         }
96         de_pop_sequence(attribute, avProtocol);
97     }
98     de_pop_sequence(service, attribute);
99 
100     // 0x0005 "Public Browse Group"
101     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_BROWSE_GROUP_LIST); // public browse group
102     attribute = de_push_sequence(service);
103     {
104         de_add_number(attribute,  DE_UUID, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_PUBLIC_BROWSE_ROOT);
105     }
106     de_pop_sequence(service, attribute);
107 
108     // 0x0009 "Bluetooth Profile Descriptor List"
109     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_BLUETOOTH_PROFILE_DESCRIPTOR_LIST);
110     attribute = de_push_sequence(service);
111     {
112         uint8_t *a2dProfile = de_push_sequence(attribute);
113         {
114             de_add_number(a2dProfile,  DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_ADVANCED_AUDIO_DISTRIBUTION);
115             de_add_number(a2dProfile,  DE_UINT, DE_SIZE_16, 0x0103);
116         }
117         de_pop_sequence(attribute, a2dProfile);
118     }
119     de_pop_sequence(service, attribute);
120 
121 
122     // 0x0100 "Service Name"
123     de_add_number(service,  DE_UINT, DE_SIZE_16, 0x0100);
124     if (service_name){
125         de_add_data(service,  DE_STRING, strlen(service_name), (uint8_t *) service_name);
126     } else {
127         de_add_data(service,  DE_STRING, strlen(default_a2dp_source_service_name), (uint8_t *) default_a2dp_source_service_name);
128     }
129 
130     // 0x0100 "Provider Name"
131     de_add_number(service,  DE_UINT, DE_SIZE_16, 0x0102);
132     if (service_provider_name){
133         de_add_data(service,  DE_STRING, strlen(service_provider_name), (uint8_t *) service_provider_name);
134     } else {
135         de_add_data(service,  DE_STRING, strlen(default_a2dp_source_service_provider_name), (uint8_t *) default_a2dp_source_service_provider_name);
136     }
137 
138     // 0x0311 "Supported Features"
139     de_add_number(service, DE_UINT, DE_SIZE_16, 0x0311);
140     de_add_number(service, DE_UINT, DE_SIZE_16, supported_features);
141 }
142 
143 static inline uint16_t a2dp_cid(void){
144     if (!sc.local_stream_endpoint) return 0;
145     if (!sc.local_stream_endpoint->connection) return 0;
146     return sc.local_stream_endpoint->connection->avdtp_cid;
147 }
148 
149 static inline uint8_t local_seid(void){
150     return avdtp_local_seid(sc.local_stream_endpoint);
151 }
152 
153 static inline uint8_t remote_seid(void){
154     return avdtp_remote_seid(sc.local_stream_endpoint);
155 }
156 
157 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){
158     if (!callback) return;
159     uint8_t event[8];
160     int pos = 0;
161     event[pos++] = HCI_EVENT_A2DP_META;
162     event[pos++] = sizeof(event) - 2;
163     event[pos++] = A2DP_SUBEVENT_STREAM_ESTABLISHED;
164     little_endian_store_16(event, pos, cid);
165     pos += 2;
166     event[pos++] = local_seid;
167     event[pos++] = remote_seid;
168     event[pos++] = status;
169     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
170 }
171 
172 static void a2dp_streaming_emit_can_send_media_packet_now(btstack_packet_handler_t callback, uint16_t cid, uint8_t seid){
173     if (!callback) return;
174     uint8_t event[8];
175     int pos = 0;
176     event[pos++] = HCI_EVENT_A2DP_META;
177     event[pos++] = sizeof(event) - 2;
178     event[pos++] = A2DP_SUBEVENT_STREAMING_CAN_SEND_MEDIA_PACKET_NOW;
179     little_endian_store_16(event, pos, cid);
180     pos += 2;
181     event[pos++] = seid;
182     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
183 }
184 
185 static void packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
186     UNUSED(channel);
187     UNUSED(size);
188 
189     uint8_t signal_identifier;
190     uint8_t status;
191     avdtp_sep_t sep;
192     uint8_t loc_seid;
193     uint8_t rem_seid;
194     uint16_t cid;
195     bd_addr_t address;
196 
197     if (packet_type != HCI_EVENT_PACKET) return;
198     if (hci_event_packet_get_type(packet) != HCI_EVENT_AVDTP_META) return;
199 
200     switch (packet[2]){
201         case AVDTP_SUBEVENT_SIGNALING_CONNECTION_ESTABLISHED:
202             avdtp_subevent_signaling_connection_established_get_bd_addr(packet, address);
203             cid = avdtp_subevent_signaling_connection_established_get_avdtp_cid(packet);
204             status = avdtp_subevent_signaling_connection_established_get_status(packet);
205             if (status != 0){
206                 log_info("AVDTP_SUBEVENT_SIGNALING_CONNECTION failed status %d ---", status);
207                 a2dp_streaming_emit_connection_established(a2dp_source_context.a2dp_callback, cid, 0, 0, status);
208                 break;
209             }
210 
211             sc.active_remote_sep = NULL;
212             next_remote_sep_index_to_query = 0;
213             app_state = A2DP_W2_DISCOVER_SEPS;
214             log_info("AVDTP_SUBEVENT_SIGNALING_CONNECTION_ESTABLISHED, avdtp cid 0x%02x ---", cid);
215             avdtp_source_discover_stream_endpoints(cid);
216             break;
217 
218         case AVDTP_SUBEVENT_SIGNALING_SEP_FOUND:
219             if (app_state != A2DP_W2_DISCOVER_SEPS) return;
220             sep.seid = avdtp_subevent_signaling_sep_found_get_remote_seid(packet);
221             sep.in_use = avdtp_subevent_signaling_sep_found_get_in_use(packet);
222             sep.media_type = (avdtp_media_type_t) avdtp_subevent_signaling_sep_found_get_media_type(packet);
223             sep.type = (avdtp_sep_type_t) avdtp_subevent_signaling_sep_found_get_sep_type(packet);
224             log_info("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);
225             break;
226 
227         case AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_SBC_CAPABILITY:{
228             if (!sc.local_stream_endpoint) return;
229             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));
230             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));
231             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));
232             uint8_t subbands = avdtp_choose_sbc_subbands(sc.local_stream_endpoint, avdtp_subevent_signaling_media_codec_sbc_capability_get_subbands_bitmap(packet));
233 
234             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));
235             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));
236             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));
237 
238             sc.local_stream_endpoint->remote_configuration.media_codec.media_codec_information[0] = (sampling_frequency << 4) | channel_mode;
239             sc.local_stream_endpoint->remote_configuration.media_codec.media_codec_information[1] = (block_length << 4) | (subbands << 2) | allocation_method;
240             sc.local_stream_endpoint->remote_configuration.media_codec.media_codec_information[2] = min_bitpool_value;
241             sc.local_stream_endpoint->remote_configuration.media_codec.media_codec_information[3] = max_bitpool_value;
242 
243             sc.local_stream_endpoint->remote_configuration_bitmap = store_bit16(sc.local_stream_endpoint->remote_configuration_bitmap, AVDTP_MEDIA_CODEC, 1);
244             sc.local_stream_endpoint->remote_configuration.media_codec.media_type = AVDTP_AUDIO;
245             sc.local_stream_endpoint->remote_configuration.media_codec.media_codec_type = AVDTP_CODEC_SBC;
246 
247             app_state = A2DP_W2_SET_CONFIGURATION;
248             break;
249         }
250         case AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_OTHER_CAPABILITY:
251             log_info("received non SBC codec. not implemented");
252             break;
253 
254         case AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_SBC_CONFIGURATION:{
255             // TODO check cid
256             sc.sampling_frequency = avdtp_subevent_signaling_media_codec_sbc_configuration_get_sampling_frequency(packet);
257             sc.block_length = avdtp_subevent_signaling_media_codec_sbc_configuration_get_block_length(packet);
258             sc.subbands = avdtp_subevent_signaling_media_codec_sbc_configuration_get_subbands(packet);
259             sc.allocation_method = avdtp_subevent_signaling_media_codec_sbc_configuration_get_allocation_method(packet) - 1;
260             sc.max_bitpool_value = avdtp_subevent_signaling_media_codec_sbc_configuration_get_max_bitpool_value(packet);
261             sc.channel_mode = avdtp_subevent_signaling_media_codec_sbc_configuration_get_channel_mode(packet);
262             // TODO: deal with reconfigure: avdtp_subevent_signaling_media_codec_sbc_configuration_get_reconfigure(packet);
263             break;
264         }
265         case AVDTP_SUBEVENT_STREAMING_CAN_SEND_MEDIA_PACKET_NOW:
266             a2dp_streaming_emit_can_send_media_packet_now(a2dp_source_context.a2dp_callback, a2dp_cid(), 0);
267             break;
268 
269         case AVDTP_SUBEVENT_STREAMING_CONNECTION_ESTABLISHED:
270             status = avdtp_subevent_streaming_connection_established_get_status(packet);
271             cid = avdtp_subevent_streaming_connection_established_get_avdtp_cid(packet);
272 
273             if (cid != a2dp_cid()){
274                 a2dp_streaming_emit_connection_established(a2dp_source_context.a2dp_callback, a2dp_cid(), local_seid(), remote_seid(), ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER);
275                 break;
276             }
277 
278             loc_seid = avdtp_subevent_streaming_connection_established_get_local_seid(packet);
279             if (loc_seid != local_seid()){
280                 a2dp_streaming_emit_connection_established(a2dp_source_context.a2dp_callback, a2dp_cid(), local_seid(), remote_seid(), ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER);
281                 break;
282             }
283 
284             rem_seid = avdtp_subevent_streaming_connection_established_get_remote_seid(packet);
285             if (status != 0){
286                 log_info("AVDTP_SUBEVENT_STREAMING_CONNECTION could not be established, status %d ---", status);
287                 a2dp_streaming_emit_connection_established(a2dp_source_context.a2dp_callback, a2dp_cid(), local_seid(), rem_seid, status);
288                 break;
289             }
290 
291             app_state = A2DP_STREAMING_OPENED;
292             a2dp_streaming_emit_connection_established(a2dp_source_context.a2dp_callback, a2dp_cid(), local_seid(), remote_seid(), 0);
293             log_info("AVDTP_SUBEVENT_STREAMING_CONNECTION_ESTABLISHED --- avdtp_cid 0x%02x, local seid %d, remote seid %d", a2dp_cid(), local_seid(), remote_seid());
294             break;
295 
296         case AVDTP_SUBEVENT_SIGNALING_ACCEPT:
297             // TODO check cid
298             signal_identifier = avdtp_subevent_signaling_accept_get_signal_identifier(packet);
299             cid = avdtp_subevent_signaling_accept_get_avdtp_cid(packet);
300             log_info("Accepted %d", signal_identifier);
301 
302             switch (app_state){
303                 case A2DP_W2_DISCOVER_SEPS:
304                     app_state = A2DP_W2_GET_ALL_CAPABILITIES;
305 
306                     sc.active_remote_sep = avdtp_source_remote_sep(cid, next_remote_sep_index_to_query++);
307                     if (!sc.active_remote_sep) {
308                         app_state = A2DP_IDLE;
309                         a2dp_streaming_emit_connection_established(a2dp_source_context.a2dp_callback, cid, 0, 0, AVDTP_SEID_DOES_NOT_EXIST);
310                         break;
311                     }
312                     log_info("Query get caps for seid %d", sc.active_remote_sep->seid);
313                     avdtp_source_get_capabilities(cid, sc.active_remote_sep->seid);
314                     break;
315                 case A2DP_W2_GET_CAPABILITIES:
316                 case A2DP_W2_GET_ALL_CAPABILITIES:
317                     if (next_remote_sep_index_to_query < avdtp_source_remote_seps_num(cid)){
318                         sc.active_remote_sep = avdtp_source_remote_sep(cid, next_remote_sep_index_to_query++);
319                         log_info("Query get caps for seid %d", sc.active_remote_sep->seid);
320                         avdtp_source_get_capabilities(cid, sc.active_remote_sep->seid);
321                     } else {
322                         log_info("No more remote seps found");
323                         app_state = A2DP_IDLE;
324                         a2dp_streaming_emit_connection_established(a2dp_source_context.a2dp_callback, cid, 0, 0, AVDTP_SEID_DOES_NOT_EXIST);
325                     }
326                     break;
327                 case A2DP_W2_SET_CONFIGURATION:{
328                     if (!sc.local_stream_endpoint) return;
329                     app_state = A2DP_W2_GET_CONFIGURATION;
330                     avdtp_source_set_configuration(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);
331                     break;
332                 }
333                 case A2DP_W2_GET_CONFIGURATION:
334                     app_state = A2DP_W2_OPEN_STREAM_WITH_SEID;
335                     avdtp_source_get_configuration(cid, sc.active_remote_sep->seid);
336                     break;
337                 case A2DP_W2_OPEN_STREAM_WITH_SEID:{
338                     app_state = A2DP_W4_OPEN_STREAM_WITH_SEID;
339                     btstack_sbc_encoder_init(&sc.sbc_encoder_state, SBC_MODE_STANDARD,
340                         sc.block_length, sc.subbands,
341                         sc.allocation_method, sc.sampling_frequency,
342                         sc.max_bitpool_value,
343                         sc.channel_mode);
344                     avdtp_source_open_stream(cid, avdtp_stream_endpoint_seid(sc.local_stream_endpoint), sc.active_remote_sep->seid);
345                     break;
346                 }
347                 case A2DP_STREAMING_OPENED:
348                     if (!a2dp_source_context.a2dp_callback) return;
349                     switch (signal_identifier){
350                         case  AVDTP_SI_START:{
351                             uint8_t event[6];
352                             int pos = 0;
353                             event[pos++] = HCI_EVENT_A2DP_META;
354                             event[pos++] = sizeof(event) - 2;
355                             event[pos++] = A2DP_SUBEVENT_STREAM_STARTED;
356                             little_endian_store_16(event, pos, a2dp_cid());
357                             pos += 2;
358                             event[pos++] = avdtp_stream_endpoint_seid(sc.local_stream_endpoint);
359                             (*a2dp_source_context.a2dp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
360                             break;
361                         }
362                         case AVDTP_SI_SUSPEND:{
363                             uint8_t event[6];
364                             int pos = 0;
365                             event[pos++] = HCI_EVENT_A2DP_META;
366                             event[pos++] = sizeof(event) - 2;
367                             event[pos++] = A2DP_SUBEVENT_STREAM_SUSPENDED;
368                             little_endian_store_16(event, pos, a2dp_cid());
369                             pos += 2;
370                             event[pos++] = avdtp_stream_endpoint_seid(sc.local_stream_endpoint);
371                             (*a2dp_source_context.a2dp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
372                             break;
373                         }
374                         case AVDTP_SI_ABORT:
375                         case AVDTP_SI_CLOSE:{
376                             uint8_t event[6];
377                             int pos = 0;
378                             event[pos++] = HCI_EVENT_A2DP_META;
379                             event[pos++] = sizeof(event) - 2;
380                             event[pos++] = A2DP_SUBEVENT_STREAM_RELEASED;
381                             little_endian_store_16(event, pos, a2dp_cid());
382                             pos += 2;
383                             log_info("send A2DP_SUBEVENT_STREAM_RELEASED to app");
384                             event[pos++] = avdtp_stream_endpoint_seid(sc.local_stream_endpoint);
385                             (*a2dp_source_context.a2dp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
386                             break;
387                         }
388                         default:
389                             break;
390                     }
391                     break;
392                 default:
393                     app_state = A2DP_IDLE;
394                     break;
395             }
396 
397             break;
398         case AVDTP_SUBEVENT_SIGNALING_REJECT:
399             app_state = A2DP_IDLE;
400             signal_identifier = avdtp_subevent_signaling_reject_get_signal_identifier(packet);
401             log_info("Rejected %d", signal_identifier);
402             break;
403         case AVDTP_SUBEVENT_SIGNALING_GENERAL_REJECT:
404             app_state = A2DP_IDLE;
405             signal_identifier = avdtp_subevent_signaling_general_reject_get_signal_identifier(packet);
406             log_info("Rejected %d", signal_identifier);
407             break;
408         case AVDTP_SUBEVENT_STREAMING_CONNECTION_RELEASED:{
409             uint8_t event[6];
410             int pos = 0;
411             event[pos++] = HCI_EVENT_AVDTP_META;
412             event[pos++] = sizeof(event) - 2;
413             event[pos++] = A2DP_SUBEVENT_STREAM_RELEASED;
414             little_endian_store_16(event, pos, avdtp_subevent_streaming_connection_released_get_avdtp_cid(packet));
415             pos += 2;
416             event[pos++] = avdtp_subevent_streaming_connection_released_get_local_seid(packet);
417             (*a2dp_source_context.a2dp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
418             break;
419         }
420         case AVDTP_SUBEVENT_SIGNALING_CONNECTION_RELEASED:
421             break;
422         default:
423             app_state = A2DP_IDLE;
424             log_info("not implemented");
425             break;
426     }
427 }
428 void a2dp_source_register_packet_handler(btstack_packet_handler_t callback){
429     if (callback == NULL){
430         log_error("a2dp_source_register_packet_handler called with NULL callback");
431         return;
432     }
433     avdtp_source_register_packet_handler(&packet_handler);
434     a2dp_source_context.a2dp_callback = callback;
435 }
436 
437 void a2dp_source_init(void){
438     avdtp_source_init(&a2dp_source_context);
439     l2cap_register_service(&packet_handler, BLUETOOTH_PROTOCOL_AVDTP, 0xffff, LEVEL_0);
440 }
441 
442 avdtp_stream_endpoint_t * a2dp_source_create_stream_endpoint(avdtp_media_type_t media_type, avdtp_media_codec_type_t media_codec_type,
443     uint8_t * codec_capabilities, uint16_t codec_capabilities_len,
444     uint8_t * media_codec_info, uint16_t media_codec_info_len){
445     avdtp_stream_endpoint_t * local_stream_endpoint = avdtp_source_create_stream_endpoint(AVDTP_SOURCE, media_type);
446     if (!local_stream_endpoint){
447         return NULL;
448     }
449     avdtp_source_register_media_transport_category(avdtp_stream_endpoint_seid(local_stream_endpoint));
450     avdtp_source_register_media_codec_category(avdtp_stream_endpoint_seid(local_stream_endpoint), media_type, media_codec_type,
451         codec_capabilities, codec_capabilities_len);
452     local_stream_endpoint->remote_configuration.media_codec.media_codec_information     = media_codec_info;
453     local_stream_endpoint->remote_configuration.media_codec.media_codec_information_len = media_codec_info_len;
454 
455     return local_stream_endpoint;
456 }
457 
458 uint8_t a2dp_source_establish_stream(bd_addr_t remote_addr, uint8_t loc_seid, uint16_t * avdtp_cid){
459     sc.local_stream_endpoint = avdtp_stream_endpoint_for_seid(loc_seid, &a2dp_source_context);
460     if (!sc.local_stream_endpoint){
461         log_error(" no local_stream_endpoint for seid %d", loc_seid);
462         return AVDTP_SEID_DOES_NOT_EXIST;
463     }
464     memcpy(sc.remote_addr, remote_addr, 6);
465     return avdtp_source_connect(remote_addr, avdtp_cid);
466 }
467 
468 uint8_t a2dp_source_disconnect(uint16_t avdtp_cid){
469     return avdtp_disconnect(avdtp_cid, &a2dp_source_context);
470 }
471 
472 uint8_t a2dp_source_start_stream(uint16_t avdtp_cid, uint8_t local_seid){
473     return avdtp_start_stream(avdtp_cid, local_seid, &a2dp_source_context);
474 }
475 
476 uint8_t a2dp_source_pause_stream(uint16_t avdtp_cid, uint8_t local_seid){
477     return avdtp_suspend_stream(avdtp_cid, local_seid, &a2dp_source_context);
478 }
479 
480 uint8_t a2dp_source_stream_endpoint_ready(uint16_t avdtp_cid, uint8_t local_seid){
481     avdtp_stream_endpoint_t * stream_endpoint = avdtp_stream_endpoint_for_seid(local_seid, &a2dp_source_context);
482     if (!stream_endpoint) {
483         log_error("No stream_endpoint with seid %d", local_seid);
484         return 0;
485     }
486     if (!stream_endpoint->connection || stream_endpoint->connection->avdtp_cid != avdtp_cid) return 0;
487     return (stream_endpoint->state == AVDTP_STREAM_ENDPOINT_STREAMING);
488 }
489 
490 static void a2dp_source_setup_media_header(uint8_t * media_packet, int size, int *offset, uint8_t marker, uint16_t sequence_number){
491     if (size < AVDTP_MEDIA_PAYLOAD_HEADER_SIZE){
492         log_error("small outgoing buffer");
493         return;
494     }
495 
496     uint8_t  rtp_version = 2;
497     uint8_t  padding = 0;
498     uint8_t  extension = 0;
499     uint8_t  csrc_count = 0;
500     uint8_t  payload_type = 0x60;
501     // uint16_t sequence_number = stream_endpoint->sequence_number;
502     uint32_t timestamp = btstack_run_loop_get_time_ms();
503     uint32_t ssrc = 0x11223344;
504 
505     // rtp header (min size 12B)
506     int pos = 0;
507     // int mtu = l2cap_get_remote_mtu_for_local_cid(stream_endpoint->l2cap_media_cid);
508 
509     media_packet[pos++] = (rtp_version << 6) | (padding << 5) | (extension << 4) | csrc_count;
510     media_packet[pos++] = (marker << 1) | payload_type;
511     big_endian_store_16(media_packet, pos, sequence_number);
512     pos += 2;
513     big_endian_store_32(media_packet, pos, timestamp);
514     pos += 4;
515     big_endian_store_32(media_packet, pos, ssrc); // only used for multicast
516     pos += 4;
517     *offset = pos;
518 }
519 
520 void a2dp_source_stream_endpoint_request_can_send_now(uint8_t local_seid){
521     avdtp_stream_endpoint_t * stream_endpoint = avdtp_stream_endpoint_for_seid(local_seid, &a2dp_source_context);
522     if (!stream_endpoint) {
523         log_error("no stream_endpoint for seid %d", local_seid);
524         return;
525     }
526     stream_endpoint->send_stream = 1;
527     avdtp_request_can_send_now_initiator(stream_endpoint->connection, stream_endpoint->l2cap_media_cid);
528 }
529 
530 int a2dp_max_media_payload_size(uint8_t local_seid){
531     avdtp_stream_endpoint_t * stream_endpoint = avdtp_stream_endpoint_for_seid(local_seid, &a2dp_source_context);
532     if (!stream_endpoint) {
533         log_error("no stream_endpoint found for seid %d", local_seid);
534         return 0;
535     }
536     if (stream_endpoint->l2cap_media_cid == 0){
537         log_error("no media cid found for seid %d", local_seid);
538         return 0;
539     }
540     return l2cap_get_remote_mtu_for_local_cid(stream_endpoint->l2cap_media_cid) - AVDTP_MEDIA_PAYLOAD_HEADER_SIZE;
541 }
542 
543 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){
544     if (size < num_bytes_to_copy + 1){
545         log_error("small outgoing buffer: buffer size %u, but need %u", size, num_bytes_to_copy + 1);
546         return;
547     }
548 
549     int pos = *offset;
550     media_packet[pos++] = num_frames; // (fragmentation << 7) | (starting_packet << 6) | (last_packet << 5) | num_frames;
551     memcpy(media_packet + pos, storage, num_bytes_to_copy);
552     pos += num_bytes_to_copy;
553     *offset = pos;
554 }
555 
556 int a2dp_source_stream_send_media_payload(uint8_t local_seid, uint8_t * storage, int num_bytes_to_copy, uint8_t num_frames, uint8_t marker){
557     avdtp_stream_endpoint_t * stream_endpoint = avdtp_stream_endpoint_for_seid(local_seid, &a2dp_source_context);
558     if (!stream_endpoint) {
559         log_error("no stream_endpoint found for seid %d", local_seid);
560         return 0;
561     }
562 
563     if (stream_endpoint->l2cap_media_cid == 0){
564         log_error("no media cid found for seid %d", local_seid);
565         return 0;
566     }
567 
568     int size = l2cap_get_remote_mtu_for_local_cid(stream_endpoint->l2cap_media_cid);
569     int offset = 0;
570 
571     l2cap_reserve_packet_buffer();
572     uint8_t * media_packet = l2cap_get_outgoing_buffer();
573     //int size = l2cap_get_remote_mtu_for_local_cid(stream_endpoint->l2cap_media_cid);
574     a2dp_source_setup_media_header(media_packet, size, &offset, marker, stream_endpoint->sequence_number);
575     a2dp_source_copy_media_payload(media_packet, size, &offset, storage, num_bytes_to_copy, num_frames);
576     stream_endpoint->sequence_number++;
577     l2cap_send_prepared(stream_endpoint->l2cap_media_cid, offset);
578     return size;
579 }
580