xref: /btstack/src/classic/avdtp_util.c (revision cbf509016daa1295a6a8b22d7314db50b88c6c9a)
1 /*
2  * Copyright (C) 2016 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL BLUEKITCHEN
24  * GMBH OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at
34  * [email protected]
35  *
36  */
37 
38 #define BTSTACK_FILE__ "avdtp_util.c"
39 
40 #include <stdint.h>
41 #include <string.h>
42 
43 #include "classic/avdtp.h"
44 #include "classic/avdtp_util.h"
45 
46 #include "btstack_debug.h"
47 #include "btstack_util.h"
48 #include "l2cap.h"
49 
50 /*
51 
52  List of AVDTP_SUBEVENTs sorted by packet handler
53 
54 
55 Sink + Source:
56 - AVDTP_SUBEVENT_SIGNALING_CONNECTION_ESTABLISHED
57 - AVDTP_SUBEVENT_SIGNALING_CONNECTION_RELEASED
58 - AVDTP_SUBEVENT_SIGNALING_SEP_FOUND
59 - AVDTP_SUBEVENT_SIGNALING_ACCEPT
60 - AVDTP_SUBEVENT_SIGNALING_REJECT
61 - AVDTP_SUBEVENT_SIGNALING_GENERAL_REJECT
62 - AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_SBC_CAPABILITY
63 - AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_OTHER_CAPABILITY
64 - AVDTP_SUBEVENT_SIGNALING_MEDIA_TRANSPORT_CAPABILITY
65 - AVDTP_SUBEVENT_SIGNALING_REPORTING_CAPABILITY
66 - AVDTP_SUBEVENT_SIGNALING_RECOVERY_CAPABILITY
67 - AVDTP_SUBEVENT_SIGNALING_CONTENT_PROTECTION_CAPABILITY
68 - AVDTP_SUBEVENT_SIGNALING_MULTIPLEXING_CAPABILITY
69 - AVDTP_SUBEVENT_SIGNALING_DELAY_REPORTING_CAPABILITY
70 - AVDTP_SUBEVENT_SIGNALING_HEADER_COMPRESSION_CAPABILITY
71 - AVDTP_SUBEVENT_SIGNALING_CAPABILITIES_DONE
72 - AVDTP_SUBEVENT_SIGNALING_SEP_DICOVERY_DONE
73 
74 Source:
75  - AVDTP_SUBEVENT_SIGNALING_DELAY_REPORT
76 
77 Sink or Source based on SEP Type:
78 - AVDTP_SUBEVENT_STREAMING_CONNECTION_ESTABLISHED
79 - AVDTP_SUBEVENT_STREAMING_CONNECTION_RELEASED
80 - AVDTP_SUBEVENT_STREAMING_CAN_SEND_MEDIA_PACKET_NOW
81 - AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_SBC_CONFIGURATION
82 - AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_OTHER_CONFIGURATION
83 
84 */
85 
86 static const char * avdtp_si_name[] = {
87     "ERROR",
88     "AVDTP_SI_DISCOVER",
89     "AVDTP_SI_GET_CAPABILITIES",
90     "AVDTP_SI_SET_CONFIGURATION",
91     "AVDTP_SI_GET_CONFIGURATION",
92     "AVDTP_SI_RECONFIGURE",
93     "AVDTP_SI_OPEN",
94     "AVDTP_SI_START",
95     "AVDTP_SI_CLOSE",
96     "AVDTP_SI_SUSPEND",
97     "AVDTP_SI_ABORT",
98     "AVDTP_SI_SECURITY_CONTROL",
99     "AVDTP_SI_GET_ALL_CAPABILITIES",
100     "AVDTP_SI_DELAY_REPORT"
101 };
102 const char * avdtp_si2str(uint16_t index){
103     if ((index <= 0) || (index >= sizeof(avdtp_si_name)/sizeof(avdtp_si_name[0]) )) return avdtp_si_name[0];
104     return avdtp_si_name[index];
105 }
106 
107 void avdtp_reset_stream_endpoint(avdtp_stream_endpoint_t * stream_endpoint){
108     stream_endpoint->media_con_handle = 0;
109     stream_endpoint->l2cap_media_cid = 0;
110     stream_endpoint->l2cap_reporting_cid = 0;
111     stream_endpoint->l2cap_recovery_cid = 0;
112 
113     stream_endpoint->state = AVDTP_STREAM_ENDPOINT_IDLE;
114     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_STREAM_CONFIG_IDLE;
115     stream_endpoint->initiator_config_state = AVDTP_INITIATOR_STREAM_CONFIG_IDLE;
116 
117     stream_endpoint->connection = NULL;
118 
119     stream_endpoint->sep.in_use = 0;
120     memset(&stream_endpoint->remote_sep, 0, sizeof(avdtp_sep_t));
121 
122     stream_endpoint->remote_capabilities_bitmap = 0;
123     memset(&stream_endpoint->remote_capabilities, 0, sizeof(avdtp_capabilities_t));
124     stream_endpoint->remote_configuration_bitmap = 0;
125     memset(&stream_endpoint->remote_configuration, 0, sizeof(avdtp_capabilities_t));
126 
127     // temporary SBC config used by A2DP Source
128     memset(stream_endpoint->media_codec_info, 0, 8);
129 
130     stream_endpoint->media_disconnect = 0;
131     stream_endpoint->media_connect = 0;
132     stream_endpoint->start_stream = 0;
133     stream_endpoint->close_stream = 0;
134     stream_endpoint->request_can_send_now = false;
135     stream_endpoint->abort_stream = 0;
136     stream_endpoint->suspend_stream = 0;
137     stream_endpoint->sequence_number = 0;
138 }
139 
140 int get_bit16(uint16_t bitmap, int position){
141     return (bitmap >> position) & 1;
142 }
143 
144 uint16_t store_bit16(uint16_t bitmap, int position, uint8_t value){
145     if (value){
146         bitmap |= 1 << position;
147     } else {
148         bitmap &= ~ (1 << position);
149     }
150     return bitmap;
151 }
152 
153 avdtp_message_type_t avdtp_get_signaling_packet_type(uint8_t * packet){
154     return (avdtp_message_type_t) (packet[0] & 0x03);
155 }
156 
157 int avdtp_read_signaling_header(avdtp_signaling_packet_t * signaling_header, uint8_t * packet, uint16_t size){
158     int pos = 0;
159     if (size < 2) return pos;
160     signaling_header->transaction_label = packet[pos] >> 4;
161     signaling_header->packet_type = (avdtp_packet_type_t)((packet[pos] >> 2) & 0x03);
162     signaling_header->message_type = (avdtp_message_type_t) (packet[pos] & 0x03);
163     pos++;
164     memset(signaling_header->command, 0, sizeof(signaling_header->command));
165     switch (signaling_header->packet_type){
166         case AVDTP_SINGLE_PACKET:
167             signaling_header->num_packets = 0;
168             signaling_header->offset = 0;
169             signaling_header->size = 0;
170             break;
171         case AVDTP_END_PACKET:
172             signaling_header->num_packets = 0;
173             break;
174         case AVDTP_START_PACKET:
175             signaling_header->num_packets = packet[pos++];
176             signaling_header->size = 0;
177             signaling_header->offset = 0;
178             break;
179         case AVDTP_CONTINUE_PACKET:
180             if (signaling_header->num_packets <= 0) {
181                 log_info("    ERROR: wrong num fragmented packets\n");
182                 break;
183             }
184             signaling_header->num_packets--;
185             break;
186         default:
187             btstack_assert(false);
188             break;
189     }
190     signaling_header->signal_identifier = (avdtp_signal_identifier_t)(packet[pos++] & 0x3f);
191     return pos;
192 }
193 
194 static bool avdtp_is_basic_capability(int service_category){
195     return (AVDTP_MEDIA_TRANSPORT <= service_category) && (service_category <= AVDTP_MEDIA_CODEC);
196 }
197 
198 int avdtp_pack_service_capabilities(uint8_t *buffer, int size, avdtp_capabilities_t caps, avdtp_service_category_t category) {
199     UNUSED(size);
200 
201     int i;
202     // pos = 0 reserved for length
203     int pos = 1;
204     switch(category){
205         case AVDTP_MEDIA_TRANSPORT:
206         case AVDTP_REPORTING:
207         case AVDTP_DELAY_REPORTING:
208             break;
209         case AVDTP_RECOVERY:
210             buffer[pos++] = caps.recovery.recovery_type; // 0x01=RFC2733
211             buffer[pos++] = caps.recovery.maximum_recovery_window_size;
212             buffer[pos++] = caps.recovery.maximum_number_media_packets;
213             break;
214         case AVDTP_CONTENT_PROTECTION:
215             buffer[pos++] = caps.content_protection.cp_type_value_len + 2;
216             big_endian_store_16(buffer, pos, caps.content_protection.cp_type);
217             pos += 2;
218             (void)memcpy(buffer + pos, caps.content_protection.cp_type_value,
219                          caps.content_protection.cp_type_value_len);
220             pos += caps.content_protection.cp_type_value_len;
221             break;
222         case AVDTP_HEADER_COMPRESSION:
223             buffer[pos++] = (caps.header_compression.back_ch << 7) | (caps.header_compression.media << 6) | (caps.header_compression.recovery << 5);
224             break;
225         case AVDTP_MULTIPLEXING:
226             buffer[pos++] = caps.multiplexing_mode.fragmentation << 7;
227             for (i=0; i<caps.multiplexing_mode.transport_identifiers_num; i++){
228                 buffer[pos++] = caps.multiplexing_mode.transport_session_identifiers[i] << 7;
229                 buffer[pos++] = caps.multiplexing_mode.tcid[i] << 7;
230                 // media, reporting. recovery
231             }
232             break;
233         case AVDTP_MEDIA_CODEC:
234             buffer[pos++] = ((uint8_t)caps.media_codec.media_type) << 4;
235             buffer[pos++] = (uint8_t)caps.media_codec.media_codec_type;
236             for (i = 0; i<caps.media_codec.media_codec_information_len; i++){
237                 buffer[pos++] = caps.media_codec.media_codec_information[i];
238             }
239             break;
240         default:
241             break;
242     }
243     buffer[0] = pos - 1; // length
244     return pos;
245 }
246 
247 static int avdtp_unpack_service_capabilities_has_errors(avdtp_connection_t * connection, avdtp_signal_identifier_t signal_identifier, avdtp_service_category_t category, uint8_t cap_len){
248     connection->error_code = 0;
249 
250     if ((category == AVDTP_SERVICE_CATEGORY_INVALID_0) ||
251         ((category == AVDTP_SERVICE_CATEGORY_INVALID_FF) && (signal_identifier == AVDTP_SI_RECONFIGURE))){
252         log_info("    ERROR: BAD SERVICE CATEGORY %d\n", category);
253         connection->reject_service_category = category;
254         connection->error_code = AVDTP_ERROR_CODE_BAD_SERV_CATEGORY;
255         return 1;
256     }
257 
258     if (signal_identifier == AVDTP_SI_RECONFIGURE){
259         if ( (category != AVDTP_CONTENT_PROTECTION) && (category != AVDTP_MEDIA_CODEC)){
260             log_info("    ERROR: REJECT CATEGORY, INVALID_CAPABILITIES\n");
261             connection->reject_service_category = category;
262             connection->error_code = AVDTP_ERROR_CODE_INVALID_CAPABILITIES;
263             return 1;
264         }
265     }
266 
267     switch(category){
268         case AVDTP_MEDIA_TRANSPORT:
269             if (cap_len != 0){
270                 log_info("    ERROR: REJECT CATEGORY, BAD_MEDIA_TRANSPORT\n");
271                 connection->reject_service_category = category;
272                 connection->error_code = AVDTP_ERROR_CODE_BAD_MEDIA_TRANSPORT_FORMAT;
273                 return 1;
274             }
275             break;
276         case AVDTP_REPORTING:
277         case AVDTP_DELAY_REPORTING:
278             if (cap_len != 0){
279                 log_info("    ERROR: REJECT CATEGORY, BAD_LENGTH\n");
280                 connection->reject_service_category = category;
281                 connection->error_code = AVDTP_ERROR_CODE_BAD_LENGTH;
282                 return 1;
283             }
284             break;
285         case AVDTP_RECOVERY:
286             if (cap_len != 3){
287                 log_info("    ERROR: REJECT CATEGORY, BAD_MEDIA_TRANSPORT\n");
288                 connection->reject_service_category = category;
289                 connection->error_code = AVDTP_ERROR_CODE_BAD_RECOVERY_FORMAT;
290                 return 1;
291             }
292             break;
293         case AVDTP_CONTENT_PROTECTION:
294             if (cap_len < 2){
295                 log_info("    ERROR: REJECT CATEGORY, BAD_CP_FORMAT\n");
296                 connection->reject_service_category = category;
297                 connection->error_code = AVDTP_ERROR_CODE_BAD_CP_FORMAT;
298                 return 1;
299             }
300             break;
301         case AVDTP_HEADER_COMPRESSION:
302             // TODO: find error code for bad header compression
303             if (cap_len != 1){
304                 log_info("    ERROR: REJECT CATEGORY, BAD_HEADER_COMPRESSION\n");
305                 connection->reject_service_category = category;
306                 connection->error_code = AVDTP_ERROR_CODE_BAD_RECOVERY_FORMAT;
307                 return 1;
308             }
309             break;
310         case AVDTP_MULTIPLEXING:
311             break;
312         case AVDTP_MEDIA_CODEC:
313             break;
314         default:
315             break;
316     }
317     return 0;
318 }
319 
320 uint16_t avdtp_unpack_service_capabilities(avdtp_connection_t * connection, avdtp_signal_identifier_t signal_identifier, avdtp_capabilities_t * caps, uint8_t * packet, uint16_t size){
321 
322     int i;
323 
324     uint16_t registered_service_categories = 0;
325     uint16_t to_process = size;
326 
327     while (to_process >= 2){
328 
329         avdtp_service_category_t category = (avdtp_service_category_t) packet[0];
330         uint8_t cap_len = packet[1];
331         packet     += 2;
332         to_process -= 2;
333 
334         if (cap_len > to_process){
335             connection->reject_service_category = category;
336             connection->error_code = AVDTP_ERROR_CODE_BAD_LENGTH;
337             return 0;
338         }
339 
340         if (avdtp_unpack_service_capabilities_has_errors(connection, signal_identifier, category, cap_len)) return 0;
341 
342         int category_valid = 1;
343 
344         uint8_t * data = packet;
345         uint16_t  pos = 0;
346 
347         switch(category){
348             case AVDTP_RECOVERY:
349                 caps->recovery.recovery_type = data[pos++];
350                 caps->recovery.maximum_recovery_window_size = data[pos++];
351                 caps->recovery.maximum_number_media_packets = data[pos++];
352                 break;
353             case AVDTP_CONTENT_PROTECTION:
354                 caps->content_protection.cp_type = big_endian_read_16(data, 0);
355                 caps->content_protection.cp_type_value_len = cap_len - 2;
356                 // connection->reject_service_category = category;
357                 // connection->error_code = UNSUPPORTED_CONFIGURATION;
358                 // support for content protection goes here
359                 break;
360             case AVDTP_HEADER_COMPRESSION:
361                 caps->header_compression.back_ch  = (data[0] >> 7) & 1;
362                 caps->header_compression.media    = (data[0] >> 6) & 1;
363                 caps->header_compression.recovery = (data[0] >> 5) & 1;
364                 break;
365             case AVDTP_MULTIPLEXING:
366                 caps->multiplexing_mode.fragmentation = (data[pos++] >> 7) & 1;
367                 // read [tsid, tcid] for media, reporting. recovery respectively
368                 caps->multiplexing_mode.transport_identifiers_num = 3;
369                 for (i=0; i<caps->multiplexing_mode.transport_identifiers_num; i++){
370                     caps->multiplexing_mode.transport_session_identifiers[i] = (data[pos++] >> 7) & 1;
371                     caps->multiplexing_mode.tcid[i] = (data[pos++] >> 7) & 1;
372                 }
373                 break;
374             case AVDTP_MEDIA_CODEC:
375                 caps->media_codec.media_type = (avdtp_media_type_t)(data[pos++] >> 4);
376                 caps->media_codec.media_codec_type = (avdtp_media_codec_type_t)(data[pos++]);
377                 caps->media_codec.media_codec_information_len = cap_len - 2;
378                 caps->media_codec.media_codec_information = &data[pos++];
379                 break;
380             case AVDTP_MEDIA_TRANSPORT:
381             case AVDTP_REPORTING:
382             case AVDTP_DELAY_REPORTING:
383                 break;
384             default:
385                 category_valid = 0;
386                 break;
387         }
388 
389         if (category_valid) {
390             registered_service_categories = store_bit16(registered_service_categories, category, 1);
391         }
392 
393         packet     += cap_len;
394         to_process -= cap_len;
395     }
396 
397     return registered_service_categories;
398 }
399 
400 void avdtp_prepare_capabilities(avdtp_signaling_packet_t * signaling_packet, uint8_t transaction_label, uint16_t service_categories, avdtp_capabilities_t capabilities, uint8_t identifier){
401     if (signaling_packet->offset) return;
402     bool basic_capabilities_only = false;
403     signaling_packet->message_type = AVDTP_RESPONSE_ACCEPT_MSG;
404     int i;
405 
406     signaling_packet->size = 0;
407     memset(signaling_packet->command, 0 , sizeof(signaling_packet->command));
408 
409     switch (identifier) {
410         case AVDTP_SI_GET_CAPABILITIES:
411             basic_capabilities_only = true;
412             break;
413         case AVDTP_SI_GET_ALL_CAPABILITIES:
414             break;
415         case AVDTP_SI_SET_CONFIGURATION:
416             signaling_packet->command[signaling_packet->size++] = signaling_packet->acp_seid << 2;
417             signaling_packet->command[signaling_packet->size++] = signaling_packet->int_seid << 2;
418             signaling_packet->message_type = AVDTP_CMD_MSG;
419             break;
420         case AVDTP_SI_RECONFIGURE:
421             signaling_packet->command[signaling_packet->size++] = signaling_packet->acp_seid << 2;
422             signaling_packet->message_type = AVDTP_CMD_MSG;
423             break;
424         default:
425             log_error("avdtp_prepare_capabilities wrong identifier %d", identifier);
426             break;
427     }
428 
429     for (i = AVDTP_MEDIA_TRANSPORT; i <= AVDTP_DELAY_REPORTING; i++){
430         int registered_category = get_bit16(service_categories, i);
431         if (!registered_category && (identifier == AVDTP_SI_SET_CONFIGURATION)){
432             // TODO: introduce bitmap of mandatory categories
433             if (i == AVDTP_MEDIA_TRANSPORT){
434                 registered_category = true;
435             }
436         }
437         // AVDTP_SI_GET_CAPABILITIES reports only basic capabilities (i.e., it skips non-basic categories)
438         if (basic_capabilities_only && !avdtp_is_basic_capability(i)){
439             registered_category = false;
440         }
441 
442         if (registered_category){
443             // service category
444             signaling_packet->command[signaling_packet->size++] = i;
445             signaling_packet->size += avdtp_pack_service_capabilities(signaling_packet->command + signaling_packet->size,
446                     sizeof(signaling_packet->command) - signaling_packet->size, capabilities, (avdtp_service_category_t) i);
447         }
448     }
449     signaling_packet->signal_identifier = (avdtp_signal_identifier_t)identifier;
450     signaling_packet->transaction_label = transaction_label;
451 }
452 
453 int avdtp_signaling_create_fragment(uint16_t cid, avdtp_signaling_packet_t * signaling_packet, uint8_t * out_buffer) {
454     int mtu = l2cap_get_remote_mtu_for_local_cid(cid);
455     int data_len = 0;
456 
457     uint16_t offset = signaling_packet->offset;
458     uint16_t pos = 1;
459 
460     if (offset == 0){
461         if (signaling_packet->size <= (mtu - 2)){
462             signaling_packet->packet_type = AVDTP_SINGLE_PACKET;
463             out_buffer[pos++] = signaling_packet->signal_identifier;
464             data_len = signaling_packet->size;
465         } else {
466             signaling_packet->packet_type = AVDTP_START_PACKET;
467             out_buffer[pos++] = (mtu + signaling_packet->size)/ (mtu-1);
468             out_buffer[pos++] = signaling_packet->signal_identifier;
469             data_len = mtu - 3;
470             signaling_packet->offset = data_len;
471         }
472     } else {
473         int remaining_bytes = signaling_packet->size - offset;
474         if (remaining_bytes <= (mtu - 1)){
475             signaling_packet->packet_type = AVDTP_END_PACKET;
476             data_len = remaining_bytes;
477             signaling_packet->offset = 0;
478         } else{
479             signaling_packet->packet_type = AVDTP_CONTINUE_PACKET;
480             data_len = mtu - 1;
481             signaling_packet->offset += data_len;
482         }
483     }
484     out_buffer[0] = avdtp_header(signaling_packet->transaction_label, signaling_packet->packet_type, signaling_packet->message_type);
485     (void)memcpy(out_buffer + pos, signaling_packet->command + offset,
486                  data_len);
487     pos += data_len;
488     return pos;
489 }
490 
491 
492 void avdtp_signaling_emit_connection_established(uint16_t avdtp_cid, bd_addr_t addr, hci_con_handle_t con_handle, uint8_t status) {
493     uint8_t event[14];
494     int pos = 0;
495     event[pos++] = HCI_EVENT_AVDTP_META;
496     event[pos++] = sizeof(event) - 2;
497     event[pos++] = AVDTP_SUBEVENT_SIGNALING_CONNECTION_ESTABLISHED;
498     little_endian_store_16(event, pos, avdtp_cid);
499     pos += 2;
500     reverse_bd_addr(addr,&event[pos]);
501     pos += 6;
502     little_endian_store_16(event, pos, con_handle);
503     pos += 2;
504     event[pos++] = status;
505     avdtp_emit_sink_and_source(event, pos);
506 }
507 
508 void avdtp_signaling_emit_connection_released(uint16_t avdtp_cid) {
509     uint8_t event[5];
510     int pos = 0;
511     event[pos++] = HCI_EVENT_AVDTP_META;
512     event[pos++] = sizeof(event) - 2;
513     event[pos++] = AVDTP_SUBEVENT_SIGNALING_CONNECTION_RELEASED;
514     little_endian_store_16(event, pos, avdtp_cid);
515     pos += 2;
516     avdtp_emit_sink_and_source(event, pos);
517 }
518 
519 void avdtp_signaling_emit_sep(uint16_t avdtp_cid, avdtp_sep_t sep) {
520     uint8_t event[9];
521     int pos = 0;
522     event[pos++] = HCI_EVENT_AVDTP_META;
523     event[pos++] = sizeof(event) - 2;
524     event[pos++] = AVDTP_SUBEVENT_SIGNALING_SEP_FOUND;
525     little_endian_store_16(event, pos, avdtp_cid);
526     pos += 2;
527     event[pos++] = sep.seid;
528     event[pos++] = sep.in_use;
529     event[pos++] = sep.media_type;
530     event[pos++] = sep.type;
531     avdtp_emit_sink_and_source(event, pos);
532 }
533 
534 void avdtp_signaling_emit_sep_done(uint16_t avdtp_cid) {
535     uint8_t event[5];
536     int pos = 0;
537     event[pos++] = HCI_EVENT_AVDTP_META;
538     event[pos++] = sizeof(event) - 2;
539     event[pos++] = AVDTP_SUBEVENT_SIGNALING_SEP_DICOVERY_DONE;
540     little_endian_store_16(event, pos, avdtp_cid);
541     pos += 2;
542     avdtp_emit_sink_and_source(event, pos);
543 }
544 
545 void avdtp_signaling_emit_accept(uint16_t avdtp_cid, uint8_t local_seid, avdtp_signal_identifier_t identifier, bool is_initiator) {
546     uint8_t event[8];
547     int pos = 0;
548     event[pos++] = HCI_EVENT_AVDTP_META;
549     event[pos++] = sizeof(event) - 2;
550     event[pos++] = AVDTP_SUBEVENT_SIGNALING_ACCEPT;
551     little_endian_store_16(event, pos, avdtp_cid);
552     pos += 2;
553     event[pos++] = local_seid;
554     event[pos++] = is_initiator ? 1 : 0;
555     event[pos++] = identifier;
556     avdtp_emit_sink_and_source(event, pos);
557 }
558 
559 void avdtp_signaling_emit_accept_for_stream_endpoint(avdtp_stream_endpoint_t * stream_endpoint, uint8_t local_seid,  avdtp_signal_identifier_t identifier, bool is_initiator){
560     uint8_t event[8];
561     int pos = 0;
562     event[pos++] = HCI_EVENT_AVDTP_META;
563     event[pos++] = sizeof(event) - 2;
564     event[pos++] = AVDTP_SUBEVENT_SIGNALING_ACCEPT;
565     little_endian_store_16(event, pos, stream_endpoint->connection->avdtp_cid);
566     pos += 2;
567     event[pos++] = local_seid;
568     event[pos++] = is_initiator ? 1 : 0;
569     event[pos++] = identifier;
570 
571     btstack_packet_handler_t packet_handler = avdtp_packet_handler_for_stream_endpoint(stream_endpoint);
572     (*packet_handler)(HCI_EVENT_PACKET, 0, event, pos);
573 }
574 
575 void avdtp_signaling_emit_reject(uint16_t avdtp_cid, uint8_t local_seid, avdtp_signal_identifier_t identifier, bool is_initiator) {
576     uint8_t event[8];
577     int pos = 0;
578     event[pos++] = HCI_EVENT_AVDTP_META;
579     event[pos++] = sizeof(event) - 2;
580     event[pos++] = AVDTP_SUBEVENT_SIGNALING_REJECT;
581     little_endian_store_16(event, pos, avdtp_cid);
582     pos += 2;
583     event[pos++] = local_seid;
584     event[pos++] = is_initiator ? 1 : 0;
585     event[pos++] = identifier;
586     avdtp_emit_sink_and_source(event, pos);
587 }
588 
589 void avdtp_signaling_emit_general_reject(uint16_t avdtp_cid, uint8_t local_seid, avdtp_signal_identifier_t identifier, bool is_initiator) {
590     uint8_t event[8];
591     int pos = 0;
592     event[pos++] = HCI_EVENT_AVDTP_META;
593     event[pos++] = sizeof(event) - 2;
594     event[pos++] = AVDTP_SUBEVENT_SIGNALING_GENERAL_REJECT;
595     little_endian_store_16(event, pos, avdtp_cid);
596     pos += 2;
597     event[pos++] = local_seid;
598     event[pos++] = is_initiator ? 1 : 0;
599     event[pos++] = identifier;
600     avdtp_emit_sink_and_source(event, pos);
601 }
602 
603 static inline void
604 avdtp_signaling_emit_capability(uint8_t capability_subevent_id, uint16_t avdtp_cid, uint8_t remote_seid) {
605     uint8_t event[6];
606     int pos = 0;
607     event[pos++] = HCI_EVENT_AVDTP_META;
608     event[pos++] = sizeof(event) - 2;
609     event[pos++] = capability_subevent_id;
610     little_endian_store_16(event, pos, avdtp_cid);
611     pos += 2;
612     event[pos++] = remote_seid;
613     avdtp_emit_sink_and_source(event, pos);
614 }
615 
616 static void avdtp_signaling_emit_media_codec_sbc_capability(uint16_t avdtp_cid, uint8_t remote_seid, adtvp_media_codec_capabilities_t media_codec) {
617     const uint8_t * media_codec_information = media_codec.media_codec_information;
618     uint8_t event[14];
619     int pos = 0;
620     event[pos++] = HCI_EVENT_AVDTP_META;
621     event[pos++] = sizeof(event) - 2;
622     event[pos++] = AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_SBC_CAPABILITY;
623     little_endian_store_16(event, pos, avdtp_cid);
624     pos += 2;
625     event[pos++] = remote_seid;
626     event[pos++] = media_codec.media_type;
627     event[pos++] = media_codec_information[0] >> 4;
628     event[pos++] = media_codec_information[0] & 0x0F;
629     event[pos++] = media_codec_information[1] >> 4;
630     event[pos++] = (media_codec_information[1] & 0x0F) >> 2;
631     event[pos++] = media_codec_information[1] & 0x03;
632     event[pos++] = media_codec_information[2];
633     event[pos++] = media_codec_information[3];
634     avdtp_emit_sink_and_source(event, pos);
635 }
636 
637 static void avdtp_signaling_emit_media_codec_mpeg_audio_capability(uint16_t avdtp_cid, uint8_t remote_seid, adtvp_media_codec_capabilities_t media_codec) {
638     const uint8_t * media_codec_information = media_codec.media_codec_information;
639     uint8_t event[15];
640     int pos = 0;
641     event[pos++] = HCI_EVENT_AVDTP_META;
642     event[pos++] = sizeof(event) - 2;
643     event[pos++] = AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_MPEG_AUDIO_CAPABILITY;
644     little_endian_store_16(event, pos, avdtp_cid);
645     pos += 2;
646     event[pos++] = remote_seid;
647     event[pos++] = media_codec.media_type;
648 
649     uint8_t layer_bitmap              =   media_codec_information[0] >> 5;
650     uint8_t crc                       =  (media_codec_information[0] >> 4) & 0x01;
651     uint8_t channel_mode_bitmap       =   media_codec_information[0] & 0x07;
652     uint8_t mpf                       =  (media_codec_information[1] >> 6) & 0x01;
653     uint8_t sampling_frequency_bitmap =   media_codec_information[1] & 0x3F;
654     uint8_t vbr                       =  (media_codec_information[2] >> 7) & 0x01;
655     uint16_t bit_rate_index_bitmap    = ((media_codec_information[3] & 0x3f) << 8) | media_codec.media_codec_information[4];
656 
657     event[pos++] = layer_bitmap;
658     event[pos++] = crc;
659     event[pos++] = channel_mode_bitmap;
660     event[pos++] = mpf;
661     event[pos++] = sampling_frequency_bitmap;
662     event[pos++] = vbr;
663     little_endian_store_16(event, pos, bit_rate_index_bitmap);           // bit rate index
664     pos += 2;
665     avdtp_emit_sink_and_source(event, pos);
666 }
667 
668 static void avdtp_signaling_emit_media_codec_mpeg_aac_capability(uint16_t avdtp_cid, uint8_t remote_seid, adtvp_media_codec_capabilities_t media_codec) {
669     const uint8_t * media_codec_information = media_codec.media_codec_information;
670     uint8_t event[15];
671     int pos = 0;
672     event[pos++] = HCI_EVENT_AVDTP_META;
673     event[pos++] = sizeof(event) - 2;
674     event[pos++] = AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_MPEG_AAC_CAPABILITY;
675     little_endian_store_16(event, pos, avdtp_cid);
676     pos += 2;
677     event[pos++] = remote_seid;
678     event[pos++] = media_codec.media_type;
679 
680     uint8_t  object_type_bitmap        =   media_codec_information[0];
681     uint16_t sampling_frequency_bitmap =  (media_codec_information[1] << 4) | (media_codec_information[2] >> 4);
682     uint8_t  channels_bitmap           =  (media_codec_information[2] >> 2) & 0x03;
683     uint32_t bit_rate_bitmap           = ((media_codec_information[3] & 0x7f) << 16) | (media_codec_information[4] << 8) | media_codec_information[5];
684     uint8_t  vbr                       =   media_codec_information[3] >> 7;
685 
686     event[pos++] =  object_type_bitmap;
687     little_endian_store_16(event, pos, sampling_frequency_bitmap);
688     pos += 2;
689     event[pos++] = channels_bitmap;
690     little_endian_store_24(event, pos, bit_rate_bitmap);
691     pos += 3;
692     event[pos++] = vbr;
693     avdtp_emit_sink_and_source(event, pos);
694 }
695 
696 static void avdtp_signaling_emit_media_codec_atrac_capability(uint16_t avdtp_cid, uint8_t remote_seid, adtvp_media_codec_capabilities_t media_codec) {
697     const uint8_t * media_codec_information = media_codec.media_codec_information;
698     uint8_t event[16];
699     int pos = 0;
700     event[pos++] = HCI_EVENT_AVDTP_META;
701     pos++; // set later
702     event[pos++] = AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_ATRAC_CAPABILITY;
703     little_endian_store_16(event, pos, avdtp_cid);
704     pos += 2;
705     event[pos++] = remote_seid;
706     event[pos++] = media_codec.media_type;
707 
708     uint8_t  version                   =  media_codec_information[0] >> 5;
709     uint8_t  channel_mode_bitmap       = (media_codec_information[0] >> 2) & 0x07;
710     uint8_t sampling_frequency_bitmap = (media_codec_information[1] >> 4) & 0x03;
711     uint8_t  vbr                       = (media_codec_information[1] >> 3) & 0x01;
712     uint16_t bit_rate_index_bitmap     = ((media_codec_information[1]) & 0x07) << 16 | (media_codec_information[2] << 8) | media_codec_information[3];
713     uint16_t maximum_sul               = (media_codec_information[4] << 8) | media_codec_information[5];
714 
715     event[pos++] = version;
716     event[pos++] = channel_mode_bitmap;
717     event[pos++] = sampling_frequency_bitmap;
718     event[pos++] = vbr;
719     little_endian_store_24(event, pos, bit_rate_index_bitmap);
720     pos += 3;
721     little_endian_store_16(event, pos, maximum_sul);
722     pos += 2;
723     event[1] = pos - 2;
724     avdtp_emit_sink_and_source(event, pos);
725 }
726 
727 static void avdtp_signaling_emit_media_codec_other_capability(uint16_t avdtp_cid, uint8_t remote_seid, adtvp_media_codec_capabilities_t media_codec) {
728     uint8_t event[AVDTP_MAX_MEDIA_CODEC_INFORMATION_LENGTH + 11];
729     int pos = 0;
730     event[pos++] = HCI_EVENT_AVDTP_META;
731     pos++; // set later
732     event[pos++] = AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_OTHER_CAPABILITY;
733     little_endian_store_16(event, pos, avdtp_cid);
734     pos += 2;
735     event[pos++] = remote_seid;
736     event[pos++] = media_codec.media_type;
737     little_endian_store_16(event, pos, media_codec.media_codec_type);
738     pos += 2;
739     little_endian_store_16(event, pos, media_codec.media_codec_information_len);
740     pos += 2;
741     uint32_t media_codec_info_len = btstack_min(media_codec.media_codec_information_len, AVDTP_MAX_MEDIA_CODEC_INFORMATION_LENGTH);
742     (void)memcpy(event + pos, media_codec.media_codec_information, media_codec_info_len);
743     pos += media_codec_info_len;
744     event[1] = pos - 2;
745     avdtp_emit_sink_and_source(event, pos);
746 }
747 
748 static void
749 avdtp_signaling_emit_media_transport_capability(uint16_t avdtp_cid, uint8_t remote_seid) {
750 	avdtp_signaling_emit_capability(AVDTP_SUBEVENT_SIGNALING_MEDIA_TRANSPORT_CAPABILITY, avdtp_cid,
751 									remote_seid);
752 }
753 
754 static void avdtp_signaling_emit_reporting_capability(uint16_t avdtp_cid, uint8_t remote_seid) {
755 	avdtp_signaling_emit_capability(AVDTP_SUBEVENT_SIGNALING_REPORTING_CAPABILITY, avdtp_cid, remote_seid);
756 }
757 
758 static void
759 avdtp_signaling_emit_delay_reporting_capability(uint16_t avdtp_cid, uint8_t remote_seid) {
760 	avdtp_signaling_emit_capability(AVDTP_SUBEVENT_SIGNALING_DELAY_REPORTING_CAPABILITY, avdtp_cid,
761 									remote_seid);
762 }
763 
764 static void avdtp_signaling_emit_recovery_capability(uint16_t avdtp_cid, uint8_t remote_seid, avdtp_recovery_capabilities_t *recovery) {
765     uint8_t event[9];
766     int pos = 0;
767     event[pos++] = HCI_EVENT_AVDTP_META;
768     event[pos++] = sizeof(event) - 2;
769     event[pos++] = AVDTP_SUBEVENT_SIGNALING_RECOVERY_CAPABILITY;
770     little_endian_store_16(event, pos, avdtp_cid);
771     pos += 2;
772     event[pos++] = remote_seid;
773     event[pos++] = recovery->recovery_type;
774     event[pos++] = recovery->maximum_recovery_window_size;
775     event[pos++] = recovery->maximum_number_media_packets;
776     avdtp_emit_sink_and_source(event, pos);
777 }
778 
779 #define MAX_CONTENT_PROTECTION_VALUE_LEN 32
780 static void
781 avdtp_signaling_emit_content_protection_capability(uint16_t avdtp_cid, uint8_t remote_seid, adtvp_content_protection_t *content_protection) {
782     uint8_t event[10 + MAX_CONTENT_PROTECTION_VALUE_LEN];
783     int pos = 0;
784     event[pos++] = HCI_EVENT_AVDTP_META;
785     pos++; // set later
786     event[pos++] = AVDTP_SUBEVENT_SIGNALING_CONTENT_PROTECTION_CAPABILITY;
787     little_endian_store_16(event, pos, avdtp_cid);
788     pos += 2;
789     event[pos++] = remote_seid;
790 
791     little_endian_store_16(event, pos, content_protection->cp_type);
792     pos += 2;
793 
794     // drop cp protection value if longer than expected
795     if (content_protection->cp_type_value_len <= MAX_CONTENT_PROTECTION_VALUE_LEN){
796         little_endian_store_16(event, pos, content_protection->cp_type_value_len);
797         pos += 2;
798         (void)memcpy(event + pos, content_protection->cp_type_value, content_protection->cp_type_value_len);
799         pos += content_protection->cp_type_value_len;
800     } else {
801         little_endian_store_16(event, pos, 0);
802         pos += 2;
803     }
804     event[1] = pos - 2;
805     avdtp_emit_sink_and_source(event, pos);
806 }
807 
808 
809 static void
810 avdtp_signaling_emit_header_compression_capability(uint16_t avdtp_cid, uint8_t remote_seid, avdtp_header_compression_capabilities_t *header_compression) {
811     uint8_t event[9];
812     int pos = 0;
813     event[pos++] = HCI_EVENT_AVDTP_META;
814     event[pos++] = sizeof(event) - 2;
815     event[pos++] = AVDTP_SUBEVENT_SIGNALING_HEADER_COMPRESSION_CAPABILITY;
816     little_endian_store_16(event, pos, avdtp_cid);
817     pos += 2;
818     event[pos++] = remote_seid;
819     event[pos++] = header_compression->back_ch;
820     event[pos++] = header_compression->media;
821     event[pos++] = header_compression->recovery;
822     avdtp_emit_sink_and_source(event, pos);
823 }
824 
825 static void
826 avdtp_signaling_emit_content_multiplexing_capability(uint16_t avdtp_cid, uint8_t remote_seid, avdtp_multiplexing_mode_capabilities_t *multiplexing_mode) {
827     uint8_t event[14];
828     int pos = 0;
829     event[pos++] = HCI_EVENT_AVDTP_META;
830     event[pos++] = sizeof(event) - 2;
831     event[pos++] = AVDTP_SUBEVENT_SIGNALING_MULTIPLEXING_CAPABILITY;
832     little_endian_store_16(event, pos, avdtp_cid);
833     pos += 2;
834     event[pos++] = remote_seid;
835 
836     event[pos++] = multiplexing_mode->fragmentation;
837     event[pos++] = multiplexing_mode->transport_identifiers_num;
838 
839     int i;
840     for (i = 0; i < 3; i++){
841         event[pos++] = multiplexing_mode->transport_session_identifiers[i];
842     }
843     for (i = 0; i < 3; i++){
844         event[pos++] = multiplexing_mode->tcid[i];
845     }
846     avdtp_emit_sink_and_source(event, pos);
847 }
848 
849 static void avdtp_signaling_emit_capability_done(uint16_t avdtp_cid, uint8_t remote_seid) {
850     uint8_t event[6];
851     int pos = 0;
852     event[pos++] = HCI_EVENT_AVDTP_META;
853     event[pos++] = sizeof(event) - 2;
854     event[pos++] = AVDTP_SUBEVENT_SIGNALING_CAPABILITIES_DONE;
855     little_endian_store_16(event, pos, avdtp_cid);
856     pos += 2;
857     event[pos++] = remote_seid;
858     avdtp_emit_sink_and_source(event, pos);
859 }
860 
861 static void avdtp_signaling_emit_media_codec_capability(uint16_t avdtp_cid, uint8_t remote_seid, adtvp_media_codec_capabilities_t media_codec){
862     switch (media_codec.media_codec_type){
863         case AVDTP_CODEC_SBC:
864             avdtp_signaling_emit_media_codec_sbc_capability(avdtp_cid, remote_seid, media_codec);
865             break;
866         case AVDTP_CODEC_MPEG_1_2_AUDIO:
867             avdtp_signaling_emit_media_codec_mpeg_audio_capability(avdtp_cid, remote_seid, media_codec);
868             break;
869         case AVDTP_CODEC_MPEG_2_4_AAC:
870             avdtp_signaling_emit_media_codec_mpeg_aac_capability(avdtp_cid, remote_seid, media_codec);
871             break;
872         case AVDTP_CODEC_ATRAC_FAMILY:
873             avdtp_signaling_emit_media_codec_atrac_capability(avdtp_cid, remote_seid, media_codec);
874             break;
875         default:
876             avdtp_signaling_emit_media_codec_other_capability(avdtp_cid, remote_seid, media_codec);
877             break;
878     }
879 }
880 
881 // emit events for all capabilities incl. final done event
882 void avdtp_signaling_emit_capabilities(uint16_t avdtp_cid, uint8_t remote_seid, avdtp_capabilities_t *capabilities,
883 									   uint16_t registered_service_categories) {
884     if (get_bit16(registered_service_categories, AVDTP_MEDIA_CODEC)){
885         avdtp_signaling_emit_media_codec_capability(avdtp_cid, remote_seid, capabilities->media_codec);
886     }
887 
888     if (get_bit16(registered_service_categories, AVDTP_MEDIA_TRANSPORT)){
889 		avdtp_signaling_emit_media_transport_capability(avdtp_cid, remote_seid);
890     }
891     if (get_bit16(registered_service_categories, AVDTP_REPORTING)){
892 		avdtp_signaling_emit_reporting_capability(avdtp_cid, remote_seid);
893     }
894     if (get_bit16(registered_service_categories, AVDTP_RECOVERY)){
895 		avdtp_signaling_emit_recovery_capability(avdtp_cid, remote_seid, &capabilities->recovery);
896     }
897     if (get_bit16(registered_service_categories, AVDTP_CONTENT_PROTECTION)){
898 		avdtp_signaling_emit_content_protection_capability(avdtp_cid, remote_seid,
899 														   &capabilities->content_protection);
900     }
901     if (get_bit16(registered_service_categories, AVDTP_HEADER_COMPRESSION)){
902 		avdtp_signaling_emit_header_compression_capability(avdtp_cid, remote_seid,
903 														   &capabilities->header_compression);
904     }
905     if (get_bit16(registered_service_categories, AVDTP_MULTIPLEXING)){
906 		avdtp_signaling_emit_content_multiplexing_capability(avdtp_cid, remote_seid,
907 															 &capabilities->multiplexing_mode);
908     }
909     if (get_bit16(registered_service_categories, AVDTP_DELAY_REPORTING)){
910 		avdtp_signaling_emit_delay_reporting_capability(avdtp_cid, remote_seid);
911     }
912 	avdtp_signaling_emit_capability_done(avdtp_cid, remote_seid);
913 }
914 
915 static uint16_t
916 avdtp_signaling_setup_media_codec_sbc_config_event(uint8_t *event, uint16_t size,
917                                                    const avdtp_stream_endpoint_t *stream_endpoint,
918                                                    uint16_t avdtp_cid, uint8_t reconfigure,
919                                                    const uint8_t *media_codec_information) {
920 
921     btstack_assert(size >= AVDTP_MEDIA_CONFIG_SBC_EVENT_LEN);
922 
923     uint8_t local_seid = avdtp_local_seid(stream_endpoint);
924     uint8_t remote_seid = avdtp_remote_seid(stream_endpoint);
925 
926     int pos = 0;
927     event[pos++] = HCI_EVENT_AVDTP_META;
928     event[pos++] = AVDTP_MEDIA_CONFIG_SBC_EVENT_LEN - 2;
929 
930     event[pos++] = AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_SBC_CONFIGURATION;
931     little_endian_store_16(event, pos, avdtp_cid);
932     pos += 2;
933     event[pos++] = local_seid;
934     event[pos++] = remote_seid;
935     event[pos++] = reconfigure;
936     event[pos++] = AVDTP_CODEC_SBC;
937 
938     uint8_t sampling_frequency_bitmap = media_codec_information[0] >> 4;
939     uint8_t channel_mode_bitmap = media_codec_information[0] & 0x0F;
940     uint8_t block_length_bitmap = media_codec_information[1] >> 4;
941     uint8_t subbands_bitmap = (media_codec_information[1] & 0x0F) >> 2;
942 
943     uint8_t num_channels = 0;
944     avdtp_channel_mode_t channel_mode;
945 
946     if (channel_mode_bitmap & AVDTP_SBC_JOINT_STEREO){
947         channel_mode = AVDTP_CHANNEL_MODE_JOINT_STEREO;
948         num_channels = 2;
949     } else if (channel_mode_bitmap & AVDTP_SBC_STEREO){
950         channel_mode = AVDTP_CHANNEL_MODE_STEREO;
951         num_channels = 2;
952     } else if (channel_mode_bitmap & AVDTP_SBC_DUAL_CHANNEL){
953         channel_mode = AVDTP_CHANNEL_MODE_DUAL_CHANNEL;
954         num_channels = 2;
955     } else {
956         channel_mode = AVDTP_CHANNEL_MODE_MONO;
957         num_channels = 1;
958     }
959 
960     uint16_t sampling_frequency = 0;
961     if (sampling_frequency_bitmap & AVDTP_SBC_48000) {
962         sampling_frequency = 48000;
963     } else if (sampling_frequency_bitmap & AVDTP_SBC_44100) {
964         sampling_frequency = 44100;
965     } else if (sampling_frequency_bitmap & AVDTP_SBC_32000) {
966         sampling_frequency = 32000;
967     } else if (sampling_frequency_bitmap & AVDTP_SBC_16000) {
968         sampling_frequency = 16000;
969     }
970 
971     uint8_t subbands = 0;
972     if (subbands_bitmap & AVDTP_SBC_SUBBANDS_8){
973         subbands = 8;
974     } else if (subbands_bitmap & AVDTP_SBC_SUBBANDS_4){
975         subbands = 4;
976     }
977 
978     uint8_t block_length = 0;
979     if (block_length_bitmap & AVDTP_SBC_BLOCK_LENGTH_16){
980         block_length = 16;
981     } else if (block_length_bitmap & AVDTP_SBC_BLOCK_LENGTH_12){
982         block_length = 12;
983     } else if (block_length_bitmap & AVDTP_SBC_BLOCK_LENGTH_8){
984         block_length = 8;
985     } else if (block_length_bitmap & AVDTP_SBC_BLOCK_LENGTH_4){
986         block_length = 4;
987     }
988 
989     little_endian_store_16(event, pos, sampling_frequency);
990     pos += 2;
991 
992     event[pos++] = (uint8_t) channel_mode;
993     event[pos++] = num_channels;
994     event[pos++] = block_length;
995     event[pos++] = subbands;
996     event[pos++] = media_codec_information[1] & 0x03;
997     event[pos++] = media_codec_information[2];
998     event[pos++] = media_codec_information[3];
999 
1000     btstack_assert(pos == AVDTP_MEDIA_CONFIG_SBC_EVENT_LEN);
1001 
1002     return pos;
1003 }
1004 
1005 static uint16_t
1006 avdtp_signaling_setup_media_codec_mpeg_audio_config_event(uint8_t *event, uint16_t size,
1007                                                           const avdtp_stream_endpoint_t *stream_endpoint,
1008                                                           uint16_t avdtp_cid, uint8_t reconfigure,
1009                                                           const uint8_t *media_codec_information) {
1010 
1011     btstack_assert(size >= AVDTP_MEDIA_CONFIG_MPEG_AUDIO_EVENT_LEN);
1012 
1013     uint8_t local_seid = avdtp_local_seid(stream_endpoint);
1014     uint8_t remote_seid = avdtp_remote_seid(stream_endpoint);
1015 
1016     uint16_t pos = 0;
1017     event[pos++] = HCI_EVENT_AVDTP_META;
1018     event[pos++] = AVDTP_MEDIA_CONFIG_MPEG_AUDIO_EVENT_LEN - 2;
1019 
1020     event[pos++] = AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_MPEG_AUDIO_CONFIGURATION;
1021     little_endian_store_16(event, pos, avdtp_cid);
1022     pos += 2;
1023     event[pos++] = local_seid;
1024     event[pos++] = remote_seid;
1025     event[pos++] = reconfigure;
1026     event[pos++] = AVDTP_CODEC_MPEG_1_2_AUDIO;
1027 
1028     uint8_t layer_bitmap              =   media_codec_information[0] >> 5;
1029     uint8_t crc                       =  (media_codec_information[0] >> 4) & 0x01;
1030     uint8_t channel_mode_bitmap       =  (media_codec_information[0] & 0x07);
1031     uint8_t mpf                       =  (media_codec_information[1] >> 6) & 0x01;
1032     uint8_t sampling_frequency_bitmap =  (media_codec_information[1] & 0x3F);
1033     uint8_t vbr                       =  (media_codec_information[2] >> 7) & 0x01;
1034     uint16_t bit_rate_index_bitmap    = ((media_codec_information[2] & 0x3f) << 8) | media_codec_information[3];
1035 
1036     uint8_t layer = 0;
1037     if (layer_bitmap & 0x04){
1038         layer = AVDTP_MPEG_LAYER_1;
1039     } else if (layer_bitmap & 0x02){
1040         layer = AVDTP_MPEG_LAYER_2;
1041     } else if (layer_bitmap & 0x01){
1042         layer = AVDTP_MPEG_LAYER_3;
1043     }
1044 
1045     uint8_t num_channels = 0;
1046     avdtp_channel_mode_t channel_mode = AVDTP_CHANNEL_MODE_JOINT_STEREO;
1047     if (channel_mode_bitmap & 0x08){
1048         num_channels = 1;
1049         channel_mode = AVDTP_CHANNEL_MODE_MONO;
1050     } else if (channel_mode_bitmap & 0x04){
1051         num_channels = 2;
1052         channel_mode = AVDTP_CHANNEL_MODE_DUAL_CHANNEL;
1053     } else if (channel_mode_bitmap & 0x02){
1054         num_channels = 2;
1055         channel_mode = AVDTP_CHANNEL_MODE_STEREO;
1056     } else if (channel_mode_bitmap & 0x02){
1057         num_channels = 2;
1058         channel_mode = AVDTP_CHANNEL_MODE_JOINT_STEREO;
1059     }
1060 
1061     uint16_t sampling_frequency = 0;
1062     if (sampling_frequency_bitmap & 0x01) {
1063         sampling_frequency = 48000;
1064     } else if (sampling_frequency_bitmap & 0x02) {
1065         sampling_frequency = 44100;
1066     } else if (sampling_frequency_bitmap & 0x04) {
1067         sampling_frequency = 32000;
1068     } else if (sampling_frequency_bitmap & 0x08) {
1069         sampling_frequency = 24000;
1070     } else if (sampling_frequency_bitmap & 0x10) {
1071         sampling_frequency = 22050;
1072     } else if (sampling_frequency_bitmap & 0x20) {
1073         sampling_frequency = 16000;
1074     }
1075 
1076     uint8_t bitrate_index = 0;
1077     uint8_t i;
1078     for (i=0;i<14;i++){
1079         if (bit_rate_index_bitmap & (1U << i)) {
1080             bitrate_index = i;
1081         }
1082     }
1083 
1084     event[pos++] = (uint8_t) layer;
1085     event[pos++] = crc;
1086     event[pos++] = (uint8_t) channel_mode;
1087     event[pos++] = num_channels;
1088     event[pos++] = mpf;
1089     little_endian_store_16(event, pos, sampling_frequency);
1090     pos += 2;
1091     event[pos++] = vbr;
1092     event[pos++] = bitrate_index;
1093 
1094     btstack_assert(pos == AVDTP_MEDIA_CONFIG_MPEG_AUDIO_EVENT_LEN);
1095 
1096     return pos;
1097 }
1098 
1099 static uint16_t
1100 avdtp_signaling_setup_media_codec_mpec_aac_config_event(uint8_t *event, uint16_t size,
1101                                                         const avdtp_stream_endpoint_t *stream_endpoint,
1102                                                         uint16_t avdtp_cid, uint8_t reconfigure,
1103                                                         const uint8_t *media_codec_information) {
1104 
1105     btstack_assert(size >= AVDTP_MEDIA_CONFIG_MPEG_AUDIO_EVENT_LEN);
1106 
1107     uint8_t local_seid = avdtp_local_seid(stream_endpoint);
1108     uint8_t remote_seid = avdtp_remote_seid(stream_endpoint);
1109 
1110     uint16_t pos = 0;
1111     event[pos++] = HCI_EVENT_AVDTP_META;
1112     event[pos++] = AVDTP_MEDIA_CONFIG_MPEG_AAC_EVENT_LEN - 2;
1113 
1114     event[pos++] = AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_MPEG_AAC_CONFIGURATION;
1115     little_endian_store_16(event, pos, avdtp_cid);
1116     pos += 2;
1117     event[pos++] = local_seid;
1118     event[pos++] = remote_seid;
1119     event[pos++] = reconfigure;
1120     event[pos++] =AVDTP_CODEC_MPEG_2_4_AAC;
1121 
1122     uint8_t  object_type_bitmap        =   media_codec_information[0];
1123     uint16_t sampling_frequency_bitmap =  (media_codec_information[1] << 4) | (media_codec_information[2] >> 4);
1124     uint8_t  channels_bitmap           =  (media_codec_information[2] >> 2) & 0x03;
1125     uint8_t  vbr                       =   media_codec_information[3] >> 7;
1126     uint32_t bit_rate                  = ((media_codec_information[3] & 0x7f) << 16) | (media_codec_information[4] << 8) | media_codec_information[5];
1127 
1128     uint8_t object_type = 0;
1129     if (object_type_bitmap & 0x80){
1130         object_type = AVDTP_AAC_MPEG2_LC;
1131     } else if (object_type_bitmap & 0x40){
1132         object_type = AVDTP_AAC_MPEG4_LC;
1133     } else if (object_type_bitmap & 0x020){
1134         object_type = AVDTP_AAC_MPEG4_LTP;
1135     } else if (object_type_bitmap & 0x010){
1136         object_type = AVDTP_AAC_MPEG4_SCALABLE;
1137     }
1138 
1139     uint32_t sampling_frequency = 0;
1140     uint8_t i;
1141     const uint32_t aac_sampling_frequency_table[] = {
1142         96000, 88200, 64000, 48000, 44100, 32000, 24000, 22050, 16000, 12000, 11025, 8000
1143     };
1144     for (i=0;i<12;i++){
1145         if (sampling_frequency_bitmap & (1U << i)) {
1146             sampling_frequency = aac_sampling_frequency_table[i];
1147         }
1148     }
1149 
1150     uint8_t num_channels = 0;
1151     if (channels_bitmap & 0x02){
1152         num_channels = 1;
1153     } else if (channels_bitmap & 0x01){
1154         num_channels = 2;
1155     }
1156 
1157     event[pos++] = object_type;
1158     little_endian_store_24(event, pos, sampling_frequency);
1159     pos += 3;
1160     event[pos++] = num_channels;
1161     little_endian_store_24(event, pos, bit_rate);
1162     pos += 3;
1163     event[pos++] = vbr;
1164 
1165     btstack_assert(AVDTP_MEDIA_CONFIG_MPEG_AAC_EVENT_LEN == pos);
1166 
1167     return pos;
1168 }
1169 
1170 static uint16_t avdtp_signaling_setup_media_codec_atrac_config_event(uint8_t *event, uint16_t size,
1171                                                                      const avdtp_stream_endpoint_t *stream_endpoint,
1172                                                                      uint16_t avdtp_cid, uint8_t reconfigure,
1173                                                                      const uint8_t *media_codec_information) {
1174     btstack_assert(size >= AVDTP_MEDIA_CONFIG_ATRAC_EVENT_LEN);
1175 
1176     uint8_t local_seid = avdtp_local_seid(stream_endpoint);
1177     uint8_t remote_seid = avdtp_remote_seid(stream_endpoint);
1178 
1179     uint16_t pos = 0;
1180     event[pos++] = HCI_EVENT_AVDTP_META;
1181     event[pos++] = AVDTP_MEDIA_CONFIG_ATRAC_EVENT_LEN - 2;
1182 
1183     event[pos++] = AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_ATRAC_CONFIGURATION;
1184     little_endian_store_16(event, pos, avdtp_cid);
1185     pos += 2;
1186     event[pos++] = local_seid;
1187     event[pos++] = remote_seid;
1188     event[pos++] = reconfigure;
1189     event[pos++] = AVDTP_CODEC_ATRAC_FAMILY;
1190 
1191     avdtp_atrac_version_t  version     = (avdtp_atrac_version_t) (media_codec_information[0] >> 5);
1192     uint8_t  channel_mode_bitmap       = (media_codec_information[0] >> 2) & 0x07;
1193     uint16_t sampling_frequency_bitmap = (media_codec_information[1] >> 4) & 0x03;
1194     uint8_t  vbr                       = (media_codec_information[1] >> 3) & 0x01;
1195     uint16_t bit_rate_index_bitmap     = ((media_codec_information[1]) & 0x07) << 16 | (media_codec_information[2] << 8) | media_codec_information[3];
1196     uint16_t maximum_sul               = (media_codec_information[4] << 8) | media_codec_information[5];
1197 
1198     uint8_t num_channels = 0;
1199     avdtp_channel_mode_t channel_mode = AVDTP_CHANNEL_MODE_JOINT_STEREO;
1200     if (channel_mode_bitmap & 0x04){
1201         num_channels = 1;
1202         channel_mode = AVDTP_CHANNEL_MODE_MONO;
1203     } else if (channel_mode_bitmap & 0x02){
1204         num_channels = 2;
1205         channel_mode = AVDTP_CHANNEL_MODE_DUAL_CHANNEL;
1206     } else if (channel_mode_bitmap & 0x01){
1207         num_channels = 2;
1208         channel_mode = AVDTP_CHANNEL_MODE_JOINT_STEREO;
1209     }
1210 
1211     uint16_t sampling_frequency = 0;
1212     if (sampling_frequency_bitmap & 0x02){
1213         sampling_frequency = 44100;
1214     } else if (sampling_frequency_bitmap & 0x01){
1215         sampling_frequency = 48000;
1216     }
1217 
1218     // bit 0 = index 0x18, bit 19 = index 0
1219     uint8_t bit_rate_index = 0;
1220     uint8_t i;
1221     for (i=0;i <= 19;i++){
1222         if (bit_rate_index_bitmap & (1U << i)) {
1223             bit_rate_index = 18 - i;
1224         }
1225     }
1226 
1227     event[pos++] = (uint8_t) version;
1228     event[pos++] = (uint8_t) channel_mode;
1229     event[pos++] = num_channels;
1230     little_endian_store_16(event, pos, sampling_frequency);
1231     pos += 2;
1232     event[pos++] = vbr;
1233     event[pos++] = bit_rate_index;
1234     little_endian_store_16(event, pos, maximum_sul);
1235     pos += 2;
1236 
1237     btstack_assert(pos == AVDTP_MEDIA_CONFIG_ATRAC_EVENT_LEN);
1238     return pos;
1239 }
1240 
1241 static uint16_t avdtp_signaling_setup_media_codec_other_config_event(uint8_t *event, uint16_t size,
1242                                                                      const avdtp_stream_endpoint_t *stream_endpoint,
1243                                                                      uint16_t avdtp_cid, uint8_t reconfigure,
1244                                                                      const adtvp_media_codec_capabilities_t *media_codec) {
1245     btstack_assert(size >= AVDTP_MEDIA_CONFIG_OTHER_EVENT_LEN);
1246 
1247     uint8_t local_seid = avdtp_local_seid(stream_endpoint);
1248     uint8_t remote_seid = avdtp_remote_seid(stream_endpoint);
1249 
1250     uint16_t pos = 0;
1251     event[pos++] = HCI_EVENT_AVDTP_META;
1252     pos++;  // set later
1253     event[pos++] = AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_OTHER_CONFIGURATION;
1254     little_endian_store_16(event, pos, avdtp_cid);
1255     pos += 2;
1256     event[pos++] = local_seid;
1257     event[pos++] = remote_seid;
1258     event[pos++] = reconfigure;
1259     event[pos++] = media_codec->media_type;
1260     little_endian_store_16(event, pos, media_codec->media_codec_type);
1261     pos += 2;
1262     little_endian_store_16(event, pos, media_codec->media_codec_information_len);
1263     pos += 2;
1264 
1265     btstack_assert(pos == 13);
1266 
1267     uint16_t media_codec_len = btstack_min(AVDTP_MAX_MEDIA_CODEC_INFORMATION_LENGTH, media_codec->media_codec_information_len);
1268     (void)memcpy(event + pos, media_codec->media_codec_information, media_codec_len);
1269     pos += media_codec_len;
1270     event[1] = pos - 2;
1271     return pos;
1272 }
1273 
1274 void avdtp_signaling_emit_delay(uint16_t avdtp_cid, uint8_t local_seid, uint16_t delay) {
1275     uint8_t event[8];
1276     int pos = 0;
1277     event[pos++] = HCI_EVENT_AVDTP_META;
1278     event[pos++] = sizeof(event) - 2;
1279     event[pos++] = AVDTP_SUBEVENT_SIGNALING_DELAY_REPORT;
1280     little_endian_store_16(event, pos, avdtp_cid);
1281     pos += 2;
1282     event[pos++] = local_seid;
1283     little_endian_store_16(event, pos, delay);
1284     pos += 2;
1285     avdtp_emit_source(event, pos);
1286 }
1287 
1288 uint16_t avdtp_setup_media_codec_config_event(uint8_t *event, uint16_t size, const avdtp_stream_endpoint_t *stream_endpoint,
1289                                               uint16_t avdtp_cid, uint8_t reconfigure,
1290                                               const adtvp_media_codec_capabilities_t * media_codec) {
1291     switch (media_codec->media_codec_type){
1292         case AVDTP_CODEC_SBC:
1293             return avdtp_signaling_setup_media_codec_sbc_config_event(event, size, stream_endpoint, avdtp_cid, reconfigure,
1294                                                                      media_codec->media_codec_information);
1295         case AVDTP_CODEC_MPEG_1_2_AUDIO:
1296             return avdtp_signaling_setup_media_codec_mpeg_audio_config_event(event, size, stream_endpoint, avdtp_cid, reconfigure,
1297                                                                              media_codec->media_codec_information);
1298         case AVDTP_CODEC_MPEG_2_4_AAC:
1299             return avdtp_signaling_setup_media_codec_mpec_aac_config_event(event, size, stream_endpoint, avdtp_cid, reconfigure,
1300                                                                            media_codec->media_codec_information);
1301         case AVDTP_CODEC_ATRAC_FAMILY:
1302             return avdtp_signaling_setup_media_codec_atrac_config_event(event, size, stream_endpoint, avdtp_cid, reconfigure,
1303                                                                         media_codec->media_codec_information);
1304         default:
1305             return avdtp_signaling_setup_media_codec_other_config_event(event, size, stream_endpoint, avdtp_cid, reconfigure,
1306                                                                         media_codec);
1307     }
1308 }
1309 
1310 void avdtp_signaling_emit_configuration(avdtp_stream_endpoint_t *stream_endpoint, uint16_t avdtp_cid, uint8_t reconfigure,
1311                                         avdtp_capabilities_t *configuration, uint16_t configured_service_categories) {
1312 
1313     if (get_bit16(configured_service_categories, AVDTP_MEDIA_CODEC)){
1314         uint16_t pos = 0;
1315         // assume MEDIA_CONFIG_OTHER_EVENT_LEN is larger than all other events
1316         uint8_t event[AVDTP_MEDIA_CONFIG_OTHER_EVENT_LEN];
1317         pos = avdtp_setup_media_codec_config_event(event, sizeof(event), stream_endpoint, avdtp_cid, reconfigure,
1318                                                    &configuration->media_codec);
1319         btstack_packet_handler_t packet_handler = avdtp_packet_handler_for_stream_endpoint(stream_endpoint);
1320         (*packet_handler)(HCI_EVENT_PACKET, 0, event, pos);
1321     }
1322 }
1323 
1324 void avdtp_streaming_emit_connection_established(avdtp_stream_endpoint_t *stream_endpoint, uint8_t status) {
1325     uint8_t event[14];
1326     int pos = 0;
1327     event[pos++] = HCI_EVENT_AVDTP_META;
1328     event[pos++] = sizeof(event) - 2;
1329     event[pos++] = AVDTP_SUBEVENT_STREAMING_CONNECTION_ESTABLISHED;
1330     little_endian_store_16(event, pos, stream_endpoint->connection->avdtp_cid);
1331     pos += 2;
1332     reverse_bd_addr(stream_endpoint->connection->remote_addr, &event[pos]);
1333     pos += 6;
1334     event[pos++] = avdtp_local_seid(stream_endpoint);
1335     event[pos++] = avdtp_remote_seid(stream_endpoint);
1336     event[pos++] = status;
1337 
1338     btstack_packet_handler_t packet_handler = avdtp_packet_handler_for_stream_endpoint(stream_endpoint);
1339     (*packet_handler)(HCI_EVENT_PACKET, 0, event, pos);
1340 }
1341 
1342 void avdtp_streaming_emit_connection_released(avdtp_stream_endpoint_t *stream_endpoint, uint16_t avdtp_cid, uint8_t local_seid) {
1343     uint8_t event[6];
1344     int pos = 0;
1345     event[pos++] = HCI_EVENT_AVDTP_META;
1346     event[pos++] = sizeof(event) - 2;
1347     event[pos++] = AVDTP_SUBEVENT_STREAMING_CONNECTION_RELEASED;
1348     little_endian_store_16(event, pos, avdtp_cid);
1349     pos += 2;
1350     event[pos++] = local_seid;
1351 
1352     btstack_packet_handler_t packet_handler = avdtp_packet_handler_for_stream_endpoint(stream_endpoint);
1353     (*packet_handler)(HCI_EVENT_PACKET, 0, event, pos);
1354 }
1355 
1356 void avdtp_streaming_emit_can_send_media_packet_now(avdtp_stream_endpoint_t *stream_endpoint, uint16_t sequence_number) {
1357     uint8_t event[8];
1358     int pos = 0;
1359     event[pos++] = HCI_EVENT_AVDTP_META;
1360     event[pos++] = sizeof(event) - 2;
1361     event[pos++] = AVDTP_SUBEVENT_STREAMING_CAN_SEND_MEDIA_PACKET_NOW;
1362     little_endian_store_16(event, pos, stream_endpoint->connection->avdtp_cid);
1363     pos += 2;
1364     event[pos++] = avdtp_local_seid(stream_endpoint);
1365     little_endian_store_16(event, pos, sequence_number);
1366     pos += 2;
1367     event[1] = pos - 2;
1368 
1369     btstack_packet_handler_t packet_handler = avdtp_packet_handler_for_stream_endpoint(stream_endpoint);
1370     (*packet_handler)(HCI_EVENT_PACKET, 0, event, pos);
1371 }
1372 
1373 uint8_t avdtp_request_can_send_now_acceptor(avdtp_connection_t *connection) {
1374     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1375     connection->wait_to_send_acceptor = true;
1376     l2cap_request_can_send_now_event(connection->l2cap_signaling_cid);
1377     return ERROR_CODE_SUCCESS;
1378 }
1379 
1380 uint8_t avdtp_request_can_send_now_initiator(avdtp_connection_t *connection) {
1381     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1382     connection->wait_to_send_initiator = true;
1383     l2cap_request_can_send_now_event(connection->l2cap_signaling_cid);
1384     return ERROR_CODE_SUCCESS;
1385 }
1386 
1387 uint8_t avdtp_local_seid(const avdtp_stream_endpoint_t * stream_endpoint){
1388     if (!stream_endpoint) return 0;
1389     return stream_endpoint->sep.seid;
1390 
1391 }
1392 
1393 uint8_t avdtp_remote_seid(const avdtp_stream_endpoint_t * stream_endpoint){
1394     if (!stream_endpoint) return AVDTP_INVALID_SEP_SEID;
1395     return stream_endpoint->remote_sep.seid;
1396 }
1397 
1398 // helper to set/get configuration
1399 void avdtp_config_sbc_set_sampling_frequency(uint8_t * config, uint16_t sampling_frequency_hz){
1400     avdtp_sbc_sampling_frequency_t sampling_frequency;
1401     switch (sampling_frequency_hz){
1402         case 16000:
1403             sampling_frequency = AVDTP_SBC_16000;
1404             break;
1405         case 32000:
1406             sampling_frequency = AVDTP_SBC_32000;
1407             break;
1408         case 48000:
1409             sampling_frequency = AVDTP_SBC_48000;
1410             break;
1411         default:
1412             sampling_frequency = AVDTP_SBC_44100;
1413             break;
1414     }
1415     config[0] = (((uint8_t) sampling_frequency) << 4) | (config[0] & 0x0f);
1416 }
1417 
1418 void avdtp_config_sbc_store(uint8_t * config, const avdtp_configuration_sbc_t * configuration){
1419     avdtp_sbc_channel_mode_t sbc_channel_mode;
1420     switch (configuration->channel_mode){
1421         case AVDTP_CHANNEL_MODE_MONO:
1422             sbc_channel_mode = AVDTP_SBC_MONO;
1423             break;
1424         case AVDTP_CHANNEL_MODE_DUAL_CHANNEL:
1425             sbc_channel_mode = AVDTP_SBC_DUAL_CHANNEL;
1426             break;
1427         case AVDTP_CHANNEL_MODE_STEREO:
1428             sbc_channel_mode = AVDTP_SBC_STEREO;
1429             break;
1430         default:
1431             sbc_channel_mode = AVDTP_SBC_JOINT_STEREO;
1432             break;
1433     }
1434     config[0] = (uint8_t) sbc_channel_mode;
1435     config[1] = (configuration->block_length << 4) | (configuration->subbands << 2) | configuration->allocation_method;
1436     config[2] = configuration-> min_bitpool_value;
1437     config[3] = configuration->max_bitpool_value;
1438     avdtp_config_sbc_set_sampling_frequency(config, configuration->sampling_frequency);
1439 }
1440 
1441 void avdtp_config_mpeg_audio_set_sampling_frequency(uint8_t * config, uint16_t sampling_frequency_hz) {
1442     uint8_t sampling_frequency_index = 0;
1443     switch (sampling_frequency_hz){
1444         case 16000:
1445             sampling_frequency_index = 5;
1446             break;
1447         case 22040:
1448             sampling_frequency_index = 4;
1449             break;
1450         case 24000:
1451             sampling_frequency_index = 3;
1452             break;
1453         case 32000:
1454             sampling_frequency_index = 2;
1455             break;
1456         case 44100:
1457             sampling_frequency_index = 1;
1458             break;
1459         case 48000:
1460             sampling_frequency_index = 0;
1461             break;
1462         default:
1463             btstack_assert(false);
1464             break;
1465     }
1466     config[1] = (config[1] & 0xC0) | (1 << sampling_frequency_index);
1467 }
1468 
1469 void avdtp_config_mpeg_audio_store(uint8_t * config, const avdtp_configuration_mpeg_audio_t * configuration){
1470 
1471     config[0] = (1 << (7 - (configuration->layer - AVDTP_MPEG_LAYER_1))) | ((configuration->crc & 0x01) << 4) | (1 << (configuration->channel_mode - AVDTP_CHANNEL_MODE_MONO));
1472     config[1] = ((configuration->media_payload_format & 0x01) << 6) ;
1473     uint16_t bit_rate_mask = 1 << configuration->bit_rate_index;
1474     config[2] = ((configuration->vbr & 0x01) << 7) | ((bit_rate_mask >> 8) & 0x3f);
1475     config[3] = bit_rate_mask & 0xff;
1476     avdtp_config_mpeg_audio_set_sampling_frequency(config, configuration->sampling_frequency);
1477 }
1478 
1479 
1480 void avdtp_config_mpeg_aac_set_sampling_frequency(uint8_t * config, uint16_t sampling_frequency_hz) {
1481     uint16_t sampling_frequency_bitmap = 0;
1482     uint8_t i;
1483     const uint32_t aac_sampling_frequency_table[] = {
1484             96000, 88200, 64000, 48000, 44100, 32000, 24000, 22050, 16000, 12000, 11025, 8000
1485     };
1486     for (i=0;i<12;i++){
1487         if (sampling_frequency_hz == aac_sampling_frequency_table[i]){
1488             sampling_frequency_bitmap = 1 << i;
1489             break;
1490         }
1491     }
1492     config[1] = sampling_frequency_bitmap >> 4;
1493     config[2] = ((sampling_frequency_bitmap & 0x0f) << 4) | (config[2] & 0x0f);
1494 }
1495 
1496 void avdtp_config_mpeg_aac_store(uint8_t * config, const avdtp_configuration_mpeg_aac_t * configuration) {
1497     config[0] = 1 << (7 -(configuration->object_type - AVDTP_AAC_MPEG2_LC));
1498     uint8_t channels_bitmap = 0;
1499     switch (configuration->channels){
1500         case 1:
1501             channels_bitmap = 0x02;
1502             break;
1503         case 2:
1504             channels_bitmap = 0x01;
1505             break;
1506         default:
1507             break;
1508     }
1509     config[2] = channels_bitmap << 2;
1510     config[3] = ((configuration->vbr & 0x01) << 7) | ((configuration->bit_rate >> 16) & 0x7f);
1511     config[4] = (configuration->bit_rate >> 8) & 0xff;
1512     config[5] =  configuration->bit_rate & 0xff;
1513     avdtp_config_mpeg_aac_set_sampling_frequency(config, configuration->sampling_frequency);
1514 }
1515 
1516 void avdtp_config_atrac_set_sampling_frequency(uint8_t * config, uint16_t sampling_frequency_hz) {
1517     uint8_t fs_bitmap = 0;
1518     switch (sampling_frequency_hz){
1519         case 44100:
1520             fs_bitmap = 2;
1521             break;
1522         case 48000:
1523             fs_bitmap = 1;
1524             break;
1525         default:
1526             break;
1527     }
1528     config[1] = (fs_bitmap << 4) | (config[1] & 0x0F);
1529 }
1530 
1531 void avdtp_config_atrac_store(uint8_t * config, const avdtp_configuration_atrac_t * configuration){
1532     uint8_t channel_mode_bitmap = 0;
1533     switch (configuration->channel_mode){
1534         case AVDTP_CHANNEL_MODE_MONO:
1535             channel_mode_bitmap = 4;
1536             break;
1537         case AVDTP_CHANNEL_MODE_DUAL_CHANNEL:
1538             channel_mode_bitmap = 2;
1539             break;
1540         case AVDTP_CHANNEL_MODE_JOINT_STEREO:
1541             channel_mode_bitmap = 1;
1542             break;
1543         default:
1544             break;
1545     }
1546     config[0] = ((configuration->version - AVDTP_ATRAC_VERSION_1 + 1) << 5) | (channel_mode_bitmap << 2);
1547     uint32_t bit_rate_bitmap = 1 << (0x18 - configuration->bit_rate_index);
1548     config[1] = ((configuration->vbr & 0x01) << 3) | ((bit_rate_bitmap >> 16) & 0x07);
1549     config[2] = (bit_rate_bitmap >> 8) & 0xff;
1550     config[3] = bit_rate_bitmap & 0xff;
1551     config[4] = configuration->maximum_sul >> 8;
1552     config[5] = configuration->maximum_sul & 0xff;
1553     config[6] = 0;
1554     avdtp_config_atrac_set_sampling_frequency(config, configuration->sampling_frequency);
1555 }
1556