xref: /btstack/src/classic/a2dp_source.c (revision 1f6397ce2204073945e420dbd6f41d2f307d7b5b)
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 #include <unistd.h>
46 
47 #include "btstack.h"
48 #include "avdtp.h"
49 #include "avdtp_util.h"
50 #include "avdtp_source.h"
51 #include "a2dp_source.h"
52 
53 static const char * default_a2dp_source_service_name = "BTstack A2DP Source Service";
54 static const char * default_a2dp_source_service_provider_name = "BTstack A2DP Source Service Provider";
55 static avdtp_context_t a2dp_source_context;
56 
57 typedef struct {
58 // to app
59     uint32_t fill_audio_ring_buffer_timeout_ms;
60     uint32_t time_audio_data_sent; // ms
61     uint32_t acc_num_missed_samples;
62     uint32_t samples_ready;
63     btstack_timer_source_t fill_audio_ring_buffer_timer;
64     btstack_ring_buffer_t sbc_ring_buffer;
65     btstack_sbc_encoder_state_t sbc_encoder_state;
66 
67     int reconfigure;
68     int num_channels;
69     int sampling_frequency;
70     int channel_mode;
71     int block_length;
72     int subbands;
73     int allocation_method;
74     int min_bitpool_value;
75     int max_bitpool_value;
76     avdtp_stream_endpoint_t * local_stream_endpoint;
77     avdtp_sep_t * active_remote_sep;
78 } avdtp_stream_endpoint_context_t;
79 
80 static a2dp_state_t app_state = A2DP_IDLE;
81 static avdtp_stream_endpoint_context_t sc;
82 static uint16_t avdtp_cid = 0;
83 static int next_remote_sep_index_to_query = 0;
84 
85 static void packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
86 
87 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){
88     uint8_t* attribute;
89     de_create_sequence(service);
90 
91     // 0x0000 "Service Record Handle"
92     de_add_number(service, DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_SERVICE_RECORD_HANDLE);
93     de_add_number(service, DE_UINT, DE_SIZE_32, service_record_handle);
94 
95     // 0x0001 "Service Class ID List"
96     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_SERVICE_CLASS_ID_LIST);
97     attribute = de_push_sequence(service);
98     {
99         de_add_number(attribute, DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_AUDIO_SOURCE);
100     }
101     de_pop_sequence(service, attribute);
102 
103     // 0x0004 "Protocol Descriptor List"
104     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_PROTOCOL_DESCRIPTOR_LIST);
105     attribute = de_push_sequence(service);
106     {
107         uint8_t* l2cpProtocol = de_push_sequence(attribute);
108         {
109             de_add_number(l2cpProtocol,  DE_UUID, DE_SIZE_16, BLUETOOTH_PROTOCOL_L2CAP);
110             de_add_number(l2cpProtocol,  DE_UINT, DE_SIZE_16, BLUETOOTH_PROTOCOL_AVDTP);
111         }
112         de_pop_sequence(attribute, l2cpProtocol);
113 
114         uint8_t* avProtocol = de_push_sequence(attribute);
115         {
116             de_add_number(avProtocol,  DE_UUID, DE_SIZE_16, BLUETOOTH_PROTOCOL_AVDTP);  // avProtocol_service
117             de_add_number(avProtocol,  DE_UINT, DE_SIZE_16,  0x0103);  // version
118         }
119         de_pop_sequence(attribute, avProtocol);
120     }
121     de_pop_sequence(service, attribute);
122 
123     // 0x0005 "Public Browse Group"
124     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_BROWSE_GROUP_LIST); // public browse group
125     attribute = de_push_sequence(service);
126     {
127         de_add_number(attribute,  DE_UUID, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_PUBLIC_BROWSE_ROOT);
128     }
129     de_pop_sequence(service, attribute);
130 
131     // 0x0009 "Bluetooth Profile Descriptor List"
132     de_add_number(service,  DE_UINT, DE_SIZE_16, BLUETOOTH_ATTRIBUTE_BLUETOOTH_PROFILE_DESCRIPTOR_LIST);
133     attribute = de_push_sequence(service);
134     {
135         uint8_t *a2dProfile = de_push_sequence(attribute);
136         {
137             de_add_number(a2dProfile,  DE_UUID, DE_SIZE_16, BLUETOOTH_SERVICE_CLASS_ADVANCED_AUDIO_DISTRIBUTION);
138             de_add_number(a2dProfile,  DE_UINT, DE_SIZE_16, 0x0103);
139         }
140         de_pop_sequence(attribute, a2dProfile);
141     }
142     de_pop_sequence(service, attribute);
143 
144 
145     // 0x0100 "Service Name"
146     de_add_number(service,  DE_UINT, DE_SIZE_16, 0x0100);
147     if (service_name){
148         de_add_data(service,  DE_STRING, strlen(service_name), (uint8_t *) service_name);
149     } else {
150         de_add_data(service,  DE_STRING, strlen(default_a2dp_source_service_name), (uint8_t *) default_a2dp_source_service_name);
151     }
152 
153     // 0x0100 "Provider Name"
154     de_add_number(service,  DE_UINT, DE_SIZE_16, 0x0102);
155     if (service_provider_name){
156         de_add_data(service,  DE_STRING, strlen(service_provider_name), (uint8_t *) service_provider_name);
157     } else {
158         de_add_data(service,  DE_STRING, strlen(default_a2dp_source_service_provider_name), (uint8_t *) default_a2dp_source_service_provider_name);
159     }
160 
161     // 0x0311 "Supported Features"
162     de_add_number(service, DE_UINT, DE_SIZE_16, 0x0311);
163     de_add_number(service, DE_UINT, DE_SIZE_16, supported_features);
164 }
165 
166 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){
167     if (!callback) return;
168     uint8_t event[8];
169     int pos = 0;
170     event[pos++] = HCI_EVENT_A2DP_META;
171     event[pos++] = sizeof(event) - 2;
172     event[pos++] = A2DP_SUBEVENT_STREAM_ESTABLISHED;
173     little_endian_store_16(event, pos, cid);
174     pos += 2;
175     event[pos++] = local_seid;
176     event[pos++] = remote_seid;
177     event[pos++] = status;
178     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
179 }
180 
181 static void a2dp_streaming_emit_can_send_media_packet_now(btstack_packet_handler_t callback, uint16_t cid, uint8_t seid){
182     if (!callback) return;
183     uint8_t event[8];
184     int pos = 0;
185     event[pos++] = HCI_EVENT_A2DP_META;
186     event[pos++] = sizeof(event) - 2;
187     event[pos++] = A2DP_SUBEVENT_STREAMING_CAN_SEND_MEDIA_PACKET_NOW;
188     little_endian_store_16(event, pos, cid);
189     pos += 2;
190     event[pos++] = seid;
191     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
192 }
193 
194 static void packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
195     UNUSED(channel);
196     UNUSED(size);
197 
198     bd_addr_t event_addr;
199     uint8_t signal_identifier;
200     uint8_t status;
201     avdtp_sep_t sep;
202     uint8_t int_seid;
203     uint8_t acp_seid;
204 
205     switch (packet_type) {
206 
207         case HCI_EVENT_PACKET:
208             switch (hci_event_packet_get_type(packet)) {
209                 case HCI_EVENT_PIN_CODE_REQUEST:
210                     // inform about pin code request
211                     printf("Pin code request - using '0000'\n");
212                     hci_event_pin_code_request_get_bd_addr(packet, event_addr);
213                     hci_send_cmd(&hci_pin_code_request_reply, &event_addr, 4, "0000");
214                     break;
215                 case HCI_EVENT_DISCONNECTION_COMPLETE:
216                     // connection closed -> quit test app
217                     printf("\n --- a2dp source --- HCI_EVENT_DISCONNECTION_COMPLETE ---\n");
218 
219                     break;
220                 case HCI_EVENT_AVDTP_META:
221                     switch (packet[2]){
222                         case AVDTP_SUBEVENT_SIGNALING_CONNECTION_ESTABLISHED:
223                             avdtp_cid = avdtp_subevent_signaling_connection_established_get_avdtp_cid(packet);
224                             status = avdtp_subevent_signaling_connection_established_get_status(packet);
225                             if (status != 0){
226                                 printf(" --- a2dp source --- AVDTP_SUBEVENT_SIGNALING_CONNECTION could not be established, status %d ---\n", status);
227                                 break;
228                             }
229                             sc.active_remote_sep = NULL;
230                             next_remote_sep_index_to_query = 0;
231                             app_state = A2DP_W2_DISCOVER_SEPS;
232                             printf(" --- a2dp source --- AVDTP_SUBEVENT_SIGNALING_CONNECTION_ESTABLISHED, avdtp cid 0x%02x ---\n", avdtp_cid);
233                             avdtp_source_discover_stream_endpoints(avdtp_cid);
234                             break;
235 
236                         case AVDTP_SUBEVENT_STREAMING_CONNECTION_ESTABLISHED:
237                             status = avdtp_subevent_streaming_connection_established_get_status(packet);
238                             avdtp_cid = avdtp_subevent_streaming_connection_established_get_avdtp_cid(packet);
239                             int_seid = avdtp_subevent_streaming_connection_established_get_int_seid(packet);
240                             acp_seid = avdtp_subevent_streaming_connection_established_get_acp_seid(packet);
241 
242                             if (status != 0){
243                                 printf(" --- a2dp source --- AVDTP_SUBEVENT_STREAMING_CONNECTION could not be established, status %d ---\n", status);
244                                 break;
245                             }
246                             app_state = A2DP_STREAMING_OPENED;
247                             a2dp_streaming_emit_connection_established(a2dp_source_context.a2dp_callback, avdtp_cid, int_seid, acp_seid, 0);
248                             printf(" --- a2dp source --- AVDTP_SUBEVENT_STREAMING_CONNECTION_ESTABLISHED --- avdtp_cid 0x%02x, local seid %d, remote seid %d\n", avdtp_cid, int_seid, acp_seid);
249                             break;
250 
251                         case AVDTP_SUBEVENT_SIGNALING_SEP_FOUND:
252                             if (app_state != A2DP_W2_DISCOVER_SEPS) return;
253                             sep.seid = avdtp_subevent_signaling_sep_found_get_seid(packet);
254                             sep.in_use = avdtp_subevent_signaling_sep_found_get_in_use(packet);
255                             sep.media_type = avdtp_subevent_signaling_sep_found_get_media_type(packet);
256                             sep.type = avdtp_subevent_signaling_sep_found_get_sep_type(packet);
257                             printf(" --- a2dp source --- Found sep: seid %u, in_use %d, media type %d, sep type %d (1-SNK)\n", sep.seid, sep.in_use, sep.media_type, sep.type);
258                             break;
259 
260                         case AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_SBC_CAPABILITY:{
261                             printf(" AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_SBC_CAPABILITY 0\n");
262                             if (!sc.local_stream_endpoint) return;
263                             printf(" AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_SBC_CAPABILITY 1\n");
264                             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));
265                             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));
266                             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));
267                             uint8_t subbands = avdtp_choose_sbc_subbands(sc.local_stream_endpoint, avdtp_subevent_signaling_media_codec_sbc_capability_get_subbands_bitmap(packet));
268 
269                             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));
270                             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));
271                             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));
272 
273                             sc.local_stream_endpoint->remote_configuration.media_codec.media_codec_information[0] = (sampling_frequency << 4) | channel_mode;
274                             sc.local_stream_endpoint->remote_configuration.media_codec.media_codec_information[1] = (block_length << 4) | (subbands << 2) | allocation_method;
275                             sc.local_stream_endpoint->remote_configuration.media_codec.media_codec_information[2] = min_bitpool_value;
276                             sc.local_stream_endpoint->remote_configuration.media_codec.media_codec_information[3] = max_bitpool_value;
277 
278                             sc.local_stream_endpoint->remote_configuration_bitmap = store_bit16(sc.local_stream_endpoint->remote_configuration_bitmap, AVDTP_MEDIA_CODEC, 1);
279                             sc.local_stream_endpoint->remote_configuration.media_codec.media_type = AVDTP_AUDIO;
280                             sc.local_stream_endpoint->remote_configuration.media_codec.media_codec_type = AVDTP_CODEC_SBC;
281 
282                             app_state = A2DP_W2_SET_CONFIGURATION;
283                             break;
284                         }
285                         case AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_OTHER_CAPABILITY:
286                             printf(" --- a2dp source ---  received non SBC codec. not implemented\n");
287                             break;
288 
289                         case AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_SBC_CONFIGURATION:{
290                             sc.sampling_frequency = avdtp_subevent_signaling_media_codec_sbc_configuration_get_sampling_frequency(packet);
291                             sc.block_length = avdtp_subevent_signaling_media_codec_sbc_configuration_get_block_length(packet);
292                             sc.subbands = avdtp_subevent_signaling_media_codec_sbc_configuration_get_subbands(packet);
293                             // switch (avdtp_subevent_signaling_media_codec_sbc_configuration_get_allocation_method(packet)){
294                             //     case AVDTP_SBC_ALLOCATION_METHOD_LOUDNESS:
295                             //         sc.allocation_method = SBC_LOUDNESS;
296                             //         break;
297                             //     case AVDTP_SBC_ALLOCATION_METHOD_SNR:
298                             //         sc.allocation_method = SBC_SNR;
299                             //         break;
300                             // }
301                             sc.allocation_method = avdtp_subevent_signaling_media_codec_sbc_configuration_get_allocation_method(packet) - 1;
302                             sc.max_bitpool_value = avdtp_subevent_signaling_media_codec_sbc_configuration_get_max_bitpool_value(packet);
303                             // TODO: deal with reconfigure: avdtp_subevent_signaling_media_codec_sbc_configuration_get_reconfigure(packet);
304                             break;
305                         }
306                         case AVDTP_SUBEVENT_STREAMING_CAN_SEND_MEDIA_PACKET_NOW:
307                             a2dp_streaming_emit_can_send_media_packet_now(a2dp_source_context.a2dp_callback, avdtp_cid, 0);
308                             break;
309 
310                         case AVDTP_SUBEVENT_SIGNALING_ACCEPT:
311                             signal_identifier = avdtp_subevent_signaling_accept_get_signal_identifier(packet);
312                             status = avdtp_subevent_signaling_accept_get_status(packet);
313                             printf(" --- a2dp source ---  Accepted %d\n", signal_identifier);
314 
315                             switch (app_state){
316                                 case A2DP_W2_DISCOVER_SEPS:
317                                     app_state = A2DP_W2_GET_ALL_CAPABILITIES;
318                                     sc.active_remote_sep = avdtp_source_remote_sep(avdtp_cid, next_remote_sep_index_to_query++);
319                                     printf(" --- a2dp source ---  Query get caps for seid %d\n", sc.active_remote_sep->seid);
320                                     avdtp_source_get_capabilities(avdtp_cid, sc.active_remote_sep->seid);
321                                     break;
322                                 case A2DP_W2_GET_CAPABILITIES:
323                                 case A2DP_W2_GET_ALL_CAPABILITIES:
324                                     if (next_remote_sep_index_to_query < avdtp_source_remote_seps_num(avdtp_cid)){
325                                         sc.active_remote_sep = avdtp_source_remote_sep(avdtp_cid, next_remote_sep_index_to_query++);
326                                         printf(" --- a2dp source ---  Query get caps for seid %d\n", sc.active_remote_sep->seid);
327                                         avdtp_source_get_capabilities(avdtp_cid, sc.active_remote_sep->seid);
328                                     } else {
329                                         printf(" --- a2dp source ---  No more remote seps found\n");
330                                         app_state = A2DP_IDLE;
331                                     }
332                                     break;
333                                 case A2DP_W2_SET_CONFIGURATION:{
334                                     if (!sc.local_stream_endpoint) return;
335                                     app_state = A2DP_W2_GET_CONFIGURATION;
336                                     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);
337                                     break;
338                                 }
339                                 case A2DP_W2_GET_CONFIGURATION:
340                                     app_state = A2DP_W2_OPEN_STREAM_WITH_SEID;
341                                     avdtp_source_get_configuration(avdtp_cid, sc.active_remote_sep->seid);
342                                     break;
343                                 case A2DP_W2_OPEN_STREAM_WITH_SEID:{
344                                     app_state = A2DP_W4_OPEN_STREAM_WITH_SEID;
345                                     btstack_sbc_encoder_init(&sc.sbc_encoder_state, SBC_MODE_STANDARD,
346                                         sc.block_length, sc.subbands,
347                                         sc.allocation_method, sc.sampling_frequency,
348                                         sc.max_bitpool_value);
349                                     avdtp_source_open_stream(avdtp_cid, avdtp_stream_endpoint_seid(sc.local_stream_endpoint), sc.active_remote_sep->seid);
350                                     break;
351                                 }
352                                 case A2DP_STREAMING_OPENED:
353                                     if (!a2dp_source_context.a2dp_callback) return;
354                                     switch (signal_identifier){
355                                         case  AVDTP_SI_START:{
356                                             uint8_t event[6];
357                                             int pos = 0;
358                                             event[pos++] = HCI_EVENT_A2DP_META;
359                                             event[pos++] = sizeof(event) - 2;
360                                             event[pos++] = A2DP_SUBEVENT_STREAM_START_ACCEPTED;
361                                             little_endian_store_16(event, pos, avdtp_cid);
362                                             pos += 2;
363                                             event[pos++] = avdtp_stream_endpoint_seid(sc.local_stream_endpoint);
364                                             (*a2dp_source_context.a2dp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
365                                             break;
366                                         }
367                                         case AVDTP_SI_CLOSE:{
368                                             uint8_t event[6];
369                                             int pos = 0;
370                                             event[pos++] = HCI_EVENT_A2DP_META;
371                                             event[pos++] = sizeof(event) - 2;
372                                             event[pos++] = A2DP_SUBEVENT_STREAM_RELEASED;
373                                             little_endian_store_16(event, pos, avdtp_cid);
374                                             pos += 2;
375                                             printf("send A2DP_SUBEVENT_STREAM_RELEASED to app\n");
376                                             event[pos++] = avdtp_stream_endpoint_seid(sc.local_stream_endpoint);
377                                             (*a2dp_source_context.a2dp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
378                                             break;
379                                         }
380                                         case AVDTP_SI_SUSPEND:{
381                                             uint8_t event[6];
382                                             int pos = 0;
383                                             event[pos++] = HCI_EVENT_A2DP_META;
384                                             event[pos++] = sizeof(event) - 2;
385                                             event[pos++] = A2DP_SUBEVENT_STREAM_SUSPENDED;
386                                             little_endian_store_16(event, pos, avdtp_cid);
387                                             pos += 2;
388                                             event[pos++] = avdtp_stream_endpoint_seid(sc.local_stream_endpoint);
389                                             (*a2dp_source_context.a2dp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
390                                             break;
391                                         }
392                                         default:
393                                             break;
394                                     }
395                                     break;
396                                 default:
397                                     app_state = A2DP_IDLE;
398                                     break;
399                             }
400 
401                             break;
402                         case AVDTP_SUBEVENT_SIGNALING_REJECT:
403                             app_state = A2DP_IDLE;
404                             signal_identifier = avdtp_subevent_signaling_reject_get_signal_identifier(packet);
405                             printf(" --- a2dp source ---  Rejected %d\n", signal_identifier);
406                             break;
407                         case AVDTP_SUBEVENT_SIGNALING_GENERAL_REJECT:
408                             app_state = A2DP_IDLE;
409                             signal_identifier = avdtp_subevent_signaling_general_reject_get_signal_identifier(packet);
410                             printf(" --- a2dp source ---  Rejected %d\n", signal_identifier);
411                             break;
412                         default:
413                             app_state = A2DP_IDLE;
414                             printf(" --- a2dp source ---  not implemented\n");
415                             break;
416                     }
417                     break;
418                 default:
419                     break;
420             }
421             break;
422         default:
423             // other packet type
424             break;
425     }
426 }
427 void a2dp_source_register_packet_handler(btstack_packet_handler_t callback){
428     if (callback == NULL){
429         log_error("a2dp_source_register_packet_handler called with NULL callback");
430         return;
431     }
432     avdtp_source_register_packet_handler(&packet_handler);
433     a2dp_source_context.a2dp_callback = callback;
434 }
435 
436 void a2dp_source_init(void){
437     avdtp_source_init(&a2dp_source_context);
438     l2cap_register_service(&packet_handler, BLUETOOTH_PROTOCOL_AVDTP, 0xffff, LEVEL_0);
439 }
440 
441 uint8_t a2dp_source_create_stream_endpoint(avdtp_media_type_t media_type, avdtp_media_codec_type_t media_codec_type,
442     uint8_t * codec_capabilities, uint16_t codec_capabilities_len,
443     uint8_t * media_codec_info, uint16_t media_codec_info_len){
444     avdtp_stream_endpoint_t * local_stream_endpoint = avdtp_source_create_stream_endpoint(AVDTP_SOURCE, media_type);
445     avdtp_source_register_media_transport_category(avdtp_stream_endpoint_seid(local_stream_endpoint));
446     avdtp_source_register_media_codec_category(avdtp_stream_endpoint_seid(local_stream_endpoint), media_type, media_codec_type,
447         codec_capabilities, codec_capabilities_len);
448     local_stream_endpoint->remote_configuration.media_codec.media_codec_information     = media_codec_info;
449     local_stream_endpoint->remote_configuration.media_codec.media_codec_information_len = media_codec_info_len;
450 
451     return local_stream_endpoint->sep.seid;
452 }
453 
454 void a2dp_source_establish_stream(bd_addr_t bd_addr, uint8_t local_seid){
455     sc.local_stream_endpoint = avdtp_stream_endpoint_for_seid(local_seid, &a2dp_source_context);
456     if (!sc.local_stream_endpoint){
457         printf(" no local_stream_endpoint for seid %d\n", local_seid);
458     }
459     avdtp_source_connect(bd_addr);
460 
461 }
462 
463 void a2dp_source_disconnect(uint16_t con_handle){
464     avdtp_disconnect(con_handle, &a2dp_source_context);
465 }
466 
467 void a2dp_source_start_stream(uint8_t int_seid){
468     avdtp_start_stream(int_seid, &a2dp_source_context);
469 }
470 
471 void a2dp_source_release_stream(uint8_t int_seid){
472     avdtp_stop_stream(int_seid, &a2dp_source_context);
473 }
474 
475 void a2dp_source_pause_stream(uint8_t int_seid){
476     avdtp_suspend_stream(int_seid, &a2dp_source_context);
477 }
478 
479 uint8_t a2dp_source_stream_endpoint_ready(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         printf("no stream_endpoint");
483         return 0;
484     }
485     return (stream_endpoint->state == AVDTP_STREAM_ENDPOINT_STREAMING);
486 }
487 
488 
489 static void a2dp_source_setup_media_header(uint8_t * media_packet, int size, int *offset, uint8_t marker, uint16_t sequence_number){
490     if (size < 12){
491         printf("small outgoing buffer\n");
492         return;
493     }
494 
495     uint8_t  rtp_version = 2;
496     uint8_t  padding = 0;
497     uint8_t  extension = 0;
498     uint8_t  csrc_count = 0;
499     uint8_t  payload_type = 0x60;
500     // uint16_t sequence_number = stream_endpoint->sequence_number;
501     uint32_t timestamp = btstack_run_loop_get_time_ms();
502     uint32_t ssrc = 0x11223344;
503 
504     // rtp header (min size 12B)
505     int pos = 0;
506     // int mtu = l2cap_get_remote_mtu_for_local_cid(stream_endpoint->l2cap_media_cid);
507 
508     media_packet[pos++] = (rtp_version << 6) | (padding << 5) | (extension << 4) | csrc_count;
509     media_packet[pos++] = (marker << 1) | payload_type;
510     big_endian_store_16(media_packet, pos, sequence_number);
511     pos += 2;
512     big_endian_store_32(media_packet, pos, timestamp);
513     pos += 4;
514     big_endian_store_32(media_packet, pos, ssrc); // only used for multicast
515     pos += 4;
516     *offset = pos;
517 }
518 
519 void a2dp_source_stream_endpoint_request_can_send_now(uint8_t local_seid){
520     avdtp_stream_endpoint_t * stream_endpoint = avdtp_stream_endpoint_for_seid(local_seid, &a2dp_source_context);
521     if (!stream_endpoint) {
522         printf("no stream_endpoint");
523         return;
524     }
525     stream_endpoint->send_stream = 1;
526     avdtp_request_can_send_now_initiator(stream_endpoint->connection, stream_endpoint->l2cap_media_cid);
527 }
528 
529 int a2dp_max_media_payload_size(uint8_t int_seid){
530     avdtp_stream_endpoint_t * stream_endpoint = avdtp_stream_endpoint_for_seid(int_seid, &a2dp_source_context);
531     if (!stream_endpoint) {
532         printf("no stream_endpoint found for seid %d", int_seid);
533         return 0;
534     }
535 
536     if (stream_endpoint->l2cap_media_cid == 0){
537         printf("no media cid found for seid %d", int_seid);
538         return 0;
539     }
540     int sbc_header_size = 12;
541     return l2cap_get_remote_mtu_for_local_cid(stream_endpoint->l2cap_media_cid) - sbc_header_size;
542 }
543 
544 uint8_t a2dp_num_frames(uint8_t int_seid, int header_size, int num_bytes_in_frame, int bytes_in_storage){
545     avdtp_stream_endpoint_t * stream_endpoint = avdtp_stream_endpoint_for_seid(int_seid, &a2dp_source_context);
546     if (!stream_endpoint) {
547         printf("no stream_endpoint found for seid %d", int_seid);
548         return 0;
549     }
550 
551     if (stream_endpoint->l2cap_media_cid == 0){
552         printf("no media cid found for seid %d", int_seid);
553         return 0;
554     }
555 
556     int num_bytes_to_populate = l2cap_get_remote_mtu_for_local_cid(stream_endpoint->l2cap_media_cid) - header_size;
557     int calc_num_frames = btstack_min(num_bytes_to_populate/num_bytes_in_frame, bytes_in_storage/num_bytes_in_frame);
558     return (uint8_t)calc_num_frames;
559 }
560 
561 static void a2dp_source_copy_media_payload(uint8_t * media_packet, int size, int * offset, btstack_ring_buffer_t * sbc_ring_buffer, uint16_t sbc_frame_bytes, uint8_t num_frames){
562     if (size < 18){
563         printf("small outgoing buffer\n");
564         return;
565     }
566     int pos = *offset;
567     // media payload
568     // sbc_header (size 1B)
569     uint8_t sbc_header_index = pos;
570     pos++;
571     uint8_t fragmentation = 0;
572     uint8_t starting_packet = 0; // set to 1 for the first packet of a fragmented SBC frame
573     uint8_t last_packet = 0;     // set to 1 for the last packet of a fragmented SBC frame
574     uint8_t _num_frames = 0;
575 
576     uint32_t total_sbc_bytes_read = 0;
577     uint8_t  sbc_frame_size = 0;
578     // payload
579     while (size - 13 - total_sbc_bytes_read >= sbc_frame_bytes && btstack_ring_buffer_bytes_available(sbc_ring_buffer)){
580         uint32_t number_of_bytes_read = 0;
581         btstack_ring_buffer_read(sbc_ring_buffer, &sbc_frame_size, 1, &number_of_bytes_read);
582         btstack_ring_buffer_read(sbc_ring_buffer, media_packet + pos, sbc_frame_size, &number_of_bytes_read);
583         pos += sbc_frame_size;
584         total_sbc_bytes_read += sbc_frame_size;
585         _num_frames++;
586         // printf("send sbc frame: timestamp %d, seq. nr %d\n", timestamp, stream_endpoint->sequence_number);
587     }
588     media_packet[sbc_header_index] =  (fragmentation << 7) | (starting_packet << 6) | (last_packet << 5) | _num_frames;
589     printf("calculated num frames %d, num frames %d\n", num_frames, _num_frames);
590     *offset = pos;
591 }
592 
593 int a2dp_source_stream_send_media_payload(uint8_t int_seid, btstack_ring_buffer_t * sbc_ring_buffer, uint16_t sbc_frame_bytes, uint8_t num_frames, uint8_t marker){
594     avdtp_stream_endpoint_t * stream_endpoint = avdtp_stream_endpoint_for_seid(int_seid, &a2dp_source_context);
595     if (!stream_endpoint) {
596         printf("no stream_endpoint found for seid %d", int_seid);
597         return 0;
598     }
599 
600     if (stream_endpoint->l2cap_media_cid == 0){
601         printf("no media cid found for seid %d", int_seid);
602         return 0;
603     }
604 
605     int size = l2cap_get_remote_mtu_for_local_cid(stream_endpoint->l2cap_media_cid);
606     int offset = 0;
607 
608     l2cap_reserve_packet_buffer();
609     uint8_t * media_packet = l2cap_get_outgoing_buffer();
610     //int size = l2cap_get_remote_mtu_for_local_cid(stream_endpoint->l2cap_media_cid);
611     a2dp_source_setup_media_header(media_packet, size, &offset, marker, stream_endpoint->sequence_number);
612     a2dp_source_copy_media_payload(media_packet, size, &offset, sbc_ring_buffer, sbc_frame_bytes, num_frames);
613     stream_endpoint->sequence_number++;
614     l2cap_send_prepared(stream_endpoint->l2cap_media_cid, offset);
615     return size;
616 }
617