xref: /btstack/src/classic/avdtp_util.c (revision cf26c8fbbf161f7e5ee9327de39264752c730a34)
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 MATTHIAS
24  * RINGWALD 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 #define MAX_MEDIA_CODEC_INFORMATION_LENGTH 100
51 
52 
53 /*
54 
55  List of AVDTP_SUBEVENTs sorted by packet handler
56 
57 
58 Sink + Source:
59 - AVDTP_SUBEVENT_SIGNALING_CONNECTION_ESTABLISHED
60 - AVDTP_SUBEVENT_SIGNALING_CONNECTION_RELEASED
61 - AVDTP_SUBEVENT_SIGNALING_SEP_FOUND
62 - AVDTP_SUBEVENT_SIGNALING_ACCEPT
63 - AVDTP_SUBEVENT_SIGNALING_REJECT
64 - AVDTP_SUBEVENT_SIGNALING_GENERAL_REJECT
65 - AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_SBC_CAPABILITY
66 - AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_OTHER_CAPABILITY
67 - AVDTP_SUBEVENT_SIGNALING_MEDIA_TRANSPORT_CAPABILITY
68 - AVDTP_SUBEVENT_SIGNALING_REPORTING_CAPABILITY
69 - AVDTP_SUBEVENT_SIGNALING_RECOVERY_CAPABILITY
70 - AVDTP_SUBEVENT_SIGNALING_CONTENT_PROTECTION_CAPABILITY
71 - AVDTP_SUBEVENT_SIGNALING_MULTIPLEXING_CAPABILITY
72 - AVDTP_SUBEVENT_SIGNALING_DELAY_REPORTING_CAPABILITY
73 - AVDTP_SUBEVENT_SIGNALING_HEADER_COMPRESSION_CAPABILITY
74 - AVDTP_SUBEVENT_SIGNALING_CAPABILITIES_DONE
75 - AVDTP_SUBEVENT_SIGNALING_SEP_DICOVERY_DONE
76 
77 Source:
78  - AVDTP_SUBEVENT_SIGNALING_DELAY_REPORT
79 
80 Sink or Source based on SEP Type:
81 - AVDTP_SUBEVENT_STREAMING_CONNECTION_ESTABLISHED
82 - AVDTP_SUBEVENT_STREAMING_CONNECTION_RELEASED
83 - AVDTP_SUBEVENT_STREAMING_CAN_SEND_MEDIA_PACKET_NOW
84 - AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_SBC_CONFIGURATION
85 - AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_OTHER_CONFIGURATION
86 
87 */
88 
89 static const char * avdtp_si_name[] = {
90     "ERROR",
91     "AVDTP_SI_DISCOVER",
92     "AVDTP_SI_GET_CAPABILITIES",
93     "AVDTP_SI_SET_CONFIGURATION",
94     "AVDTP_SI_GET_CONFIGURATION",
95     "AVDTP_SI_RECONFIGURE",
96     "AVDTP_SI_OPEN",
97     "AVDTP_SI_START",
98     "AVDTP_SI_CLOSE",
99     "AVDTP_SI_SUSPEND",
100     "AVDTP_SI_ABORT",
101     "AVDTP_SI_SECURITY_CONTROL",
102     "AVDTP_SI_GET_ALL_CAPABILITIES",
103     "AVDTP_SI_DELAY_REPORT"
104 };
105 const char * avdtp_si2str(uint16_t index){
106     if ((index <= 0) || (index >= sizeof(avdtp_si_name)/sizeof(avdtp_si_name[0]) )) return avdtp_si_name[0];
107     return avdtp_si_name[index];
108 }
109 
110 void avdtp_reset_stream_endpoint(avdtp_stream_endpoint_t * stream_endpoint){
111     stream_endpoint->media_con_handle = 0;
112     stream_endpoint->l2cap_media_cid = 0;
113     stream_endpoint->l2cap_reporting_cid = 0;
114     stream_endpoint->l2cap_recovery_cid = 0;
115 
116     stream_endpoint->state = AVDTP_STREAM_ENDPOINT_IDLE;
117     stream_endpoint->acceptor_config_state = AVDTP_ACCEPTOR_STREAM_CONFIG_IDLE;
118     stream_endpoint->initiator_config_state = AVDTP_INITIATOR_STREAM_CONFIG_IDLE;
119 
120     stream_endpoint->connection = NULL;
121 
122     stream_endpoint->sep.in_use = 0;
123     memset(&stream_endpoint->remote_sep, 0, sizeof(avdtp_sep_t));
124 
125     stream_endpoint->remote_capabilities_bitmap = 0;
126     memset(&stream_endpoint->remote_capabilities, 0, sizeof(avdtp_capabilities_t));
127     stream_endpoint->remote_configuration_bitmap = 0;
128     memset(&stream_endpoint->remote_configuration, 0, sizeof(avdtp_capabilities_t));
129 
130     // temporary SBC config used by A2DP Source
131     memset(stream_endpoint->media_codec_info, 0, 8);
132 
133     stream_endpoint->media_disconnect = 0;
134     stream_endpoint->media_connect = 0;
135     stream_endpoint->start_stream = 0;
136     stream_endpoint->close_stream = 0;
137     stream_endpoint->request_can_send_now = 0;
138     stream_endpoint->abort_stream = 0;
139     stream_endpoint->suspend_stream = 0;
140     stream_endpoint->sequence_number = 0;
141 }
142 
143 int get_bit16(uint16_t bitmap, int position){
144     return (bitmap >> position) & 1;
145 }
146 
147 uint16_t store_bit16(uint16_t bitmap, int position, uint8_t value){
148     if (value){
149         bitmap |= 1 << position;
150     } else {
151         bitmap &= ~ (1 << position);
152     }
153     return bitmap;
154 }
155 
156 avdtp_message_type_t avdtp_get_signaling_packet_type(uint8_t * packet){
157     return (avdtp_message_type_t) (packet[0] & 0x03);
158 }
159 
160 int avdtp_read_signaling_header(avdtp_signaling_packet_t * signaling_header, uint8_t * packet, uint16_t size){
161     int pos = 0;
162     if (size < 2) return pos;
163     signaling_header->transaction_label = packet[pos] >> 4;
164     signaling_header->packet_type = (avdtp_packet_type_t)((packet[pos] >> 2) & 0x03);
165     signaling_header->message_type = (avdtp_message_type_t) (packet[pos] & 0x03);
166     pos++;
167     memset(signaling_header->command, 0, sizeof(signaling_header->command));
168     switch (signaling_header->packet_type){
169         case AVDTP_SINGLE_PACKET:
170             signaling_header->num_packets = 0;
171             signaling_header->offset = 0;
172             signaling_header->size = 0;
173             break;
174         case AVDTP_END_PACKET:
175             signaling_header->num_packets = 0;
176             break;
177         case AVDTP_START_PACKET:
178             signaling_header->num_packets = packet[pos++];
179             signaling_header->size = 0;
180             signaling_header->offset = 0;
181             break;
182         case AVDTP_CONTINUE_PACKET:
183             if (signaling_header->num_packets <= 0) {
184                 log_info("    ERROR: wrong num fragmented packets\n");
185                 break;
186             }
187             signaling_header->num_packets--;
188             break;
189         default:
190             btstack_assert(false);
191             break;
192     }
193     signaling_header->signal_identifier = (avdtp_signal_identifier_t)(packet[pos++] & 0x3f);
194     return pos;
195 }
196 
197 static bool avdtp_is_basic_capability(int service_category){
198     return (AVDTP_MEDIA_TRANSPORT <= service_category) && (service_category <= AVDTP_MEDIA_CODEC);
199 }
200 
201 int avdtp_pack_service_capabilities(uint8_t *buffer, int size, avdtp_capabilities_t caps, avdtp_service_category_t category) {
202     UNUSED(size);
203 
204     int i;
205     // pos = 0 reserved for length
206     int pos = 1;
207     switch(category){
208         case AVDTP_MEDIA_TRANSPORT:
209         case AVDTP_REPORTING:
210         case AVDTP_DELAY_REPORTING:
211             break;
212         case AVDTP_RECOVERY:
213             buffer[pos++] = caps.recovery.recovery_type; // 0x01=RFC2733
214             buffer[pos++] = caps.recovery.maximum_recovery_window_size;
215             buffer[pos++] = caps.recovery.maximum_number_media_packets;
216             break;
217         case AVDTP_CONTENT_PROTECTION:
218             buffer[pos++] = caps.content_protection.cp_type_value_len + 2;
219             big_endian_store_16(buffer, pos, caps.content_protection.cp_type);
220             pos += 2;
221             (void)memcpy(buffer + pos, caps.content_protection.cp_type_value,
222                          caps.content_protection.cp_type_value_len);
223             pos += caps.content_protection.cp_type_value_len;
224             break;
225         case AVDTP_HEADER_COMPRESSION:
226             buffer[pos++] = (caps.header_compression.back_ch << 7) | (caps.header_compression.media << 6) | (caps.header_compression.recovery << 5);
227             break;
228         case AVDTP_MULTIPLEXING:
229             buffer[pos++] = caps.multiplexing_mode.fragmentation << 7;
230             for (i=0; i<caps.multiplexing_mode.transport_identifiers_num; i++){
231                 buffer[pos++] = caps.multiplexing_mode.transport_session_identifiers[i] << 7;
232                 buffer[pos++] = caps.multiplexing_mode.tcid[i] << 7;
233                 // media, reporting. recovery
234             }
235             break;
236         case AVDTP_MEDIA_CODEC:
237             buffer[pos++] = ((uint8_t)caps.media_codec.media_type) << 4;
238             buffer[pos++] = (uint8_t)caps.media_codec.media_codec_type;
239             for (i = 0; i<caps.media_codec.media_codec_information_len; i++){
240                 buffer[pos++] = caps.media_codec.media_codec_information[i];
241             }
242             break;
243         default:
244             break;
245     }
246     buffer[0] = pos - 1; // length
247     return pos;
248 }
249 
250 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){
251     connection->error_code = 0;
252 
253     if ((category == AVDTP_SERVICE_CATEGORY_INVALID_0) ||
254         ((category == AVDTP_SERVICE_CATEGORY_INVALID_FF) && (signal_identifier == AVDTP_SI_RECONFIGURE))){
255         log_info("    ERROR: BAD SERVICE CATEGORY %d\n", category);
256         connection->reject_service_category = category;
257         connection->error_code = AVDTP_ERROR_CODE_BAD_SERV_CATEGORY;
258         return 1;
259     }
260 
261     if (signal_identifier == AVDTP_SI_RECONFIGURE){
262         if ( (category != AVDTP_CONTENT_PROTECTION) && (category != AVDTP_MEDIA_CODEC)){
263             log_info("    ERROR: REJECT CATEGORY, INVALID_CAPABILITIES\n");
264             connection->reject_service_category = category;
265             connection->error_code = AVDTP_ERROR_CODE_INVALID_CAPABILITIES;
266             return 1;
267         }
268     }
269 
270     switch(category){
271         case AVDTP_MEDIA_TRANSPORT:
272             if (cap_len != 0){
273                 log_info("    ERROR: REJECT CATEGORY, BAD_MEDIA_TRANSPORT\n");
274                 connection->reject_service_category = category;
275                 connection->error_code = AVDTP_ERROR_CODE_BAD_MEDIA_TRANSPORT_FORMAT;
276                 return 1;
277             }
278             break;
279         case AVDTP_REPORTING:
280         case AVDTP_DELAY_REPORTING:
281             if (cap_len != 0){
282                 log_info("    ERROR: REJECT CATEGORY, BAD_LENGTH\n");
283                 connection->reject_service_category = category;
284                 connection->error_code = AVDTP_ERROR_CODE_BAD_LENGTH;
285                 return 1;
286             }
287             break;
288         case AVDTP_RECOVERY:
289             if (cap_len != 3){
290                 log_info("    ERROR: REJECT CATEGORY, BAD_MEDIA_TRANSPORT\n");
291                 connection->reject_service_category = category;
292                 connection->error_code = AVDTP_ERROR_CODE_BAD_RECOVERY_FORMAT;
293                 return 1;
294             }
295             break;
296         case AVDTP_CONTENT_PROTECTION:
297             if (cap_len < 2){
298                 log_info("    ERROR: REJECT CATEGORY, BAD_CP_FORMAT\n");
299                 connection->reject_service_category = category;
300                 connection->error_code = AVDTP_ERROR_CODE_BAD_CP_FORMAT;
301                 return 1;
302             }
303             break;
304         case AVDTP_HEADER_COMPRESSION:
305             // TODO: find error code for bad header compression
306             if (cap_len != 1){
307                 log_info("    ERROR: REJECT CATEGORY, BAD_HEADER_COMPRESSION\n");
308                 connection->reject_service_category = category;
309                 connection->error_code = AVDTP_ERROR_CODE_BAD_RECOVERY_FORMAT;
310                 return 1;
311             }
312             break;
313         case AVDTP_MULTIPLEXING:
314             break;
315         case AVDTP_MEDIA_CODEC:
316             break;
317         default:
318             break;
319     }
320     return 0;
321 }
322 
323 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){
324 
325     int i;
326 
327     uint16_t registered_service_categories = 0;
328     uint16_t to_process = size;
329 
330     while (to_process >= 2){
331 
332         avdtp_service_category_t category = (avdtp_service_category_t) packet[0];
333         uint8_t cap_len = packet[1];
334         packet     += 2;
335         to_process -= 2;
336 
337         if (cap_len > to_process){
338             connection->reject_service_category = category;
339             connection->error_code = AVDTP_ERROR_CODE_BAD_LENGTH;
340             return 0;
341         }
342 
343         if (avdtp_unpack_service_capabilities_has_errors(connection, signal_identifier, category, cap_len)) return 0;
344 
345         int category_valid = 1;
346 
347         uint8_t * data = packet;
348         uint16_t  pos = 0;
349 
350         switch(category){
351             case AVDTP_RECOVERY:
352                 caps->recovery.recovery_type = data[pos++];
353                 caps->recovery.maximum_recovery_window_size = data[pos++];
354                 caps->recovery.maximum_number_media_packets = data[pos++];
355                 break;
356             case AVDTP_CONTENT_PROTECTION:
357                 caps->content_protection.cp_type = big_endian_read_16(data, 0);
358                 caps->content_protection.cp_type_value_len = cap_len - 2;
359                 // connection->reject_service_category = category;
360                 // connection->error_code = UNSUPPORTED_CONFIGURATION;
361                 // support for content protection goes here
362                 break;
363             case AVDTP_HEADER_COMPRESSION:
364                 caps->header_compression.back_ch  = (data[0] >> 7) & 1;
365                 caps->header_compression.media    = (data[0] >> 6) & 1;
366                 caps->header_compression.recovery = (data[0] >> 5) & 1;
367                 break;
368             case AVDTP_MULTIPLEXING:
369                 caps->multiplexing_mode.fragmentation = (data[pos++] >> 7) & 1;
370                 // read [tsid, tcid] for media, reporting. recovery respectively
371                 caps->multiplexing_mode.transport_identifiers_num = 3;
372                 for (i=0; i<caps->multiplexing_mode.transport_identifiers_num; i++){
373                     caps->multiplexing_mode.transport_session_identifiers[i] = (data[pos++] >> 7) & 1;
374                     caps->multiplexing_mode.tcid[i] = (data[pos++] >> 7) & 1;
375                 }
376                 break;
377             case AVDTP_MEDIA_CODEC:
378                 caps->media_codec.media_type = (avdtp_media_type_t)(data[pos++] >> 4);
379                 caps->media_codec.media_codec_type = (avdtp_media_codec_type_t)(data[pos++]);
380                 caps->media_codec.media_codec_information_len = cap_len - 2;
381                 caps->media_codec.media_codec_information = &data[pos++];
382                 break;
383             case AVDTP_MEDIA_TRANSPORT:
384             case AVDTP_REPORTING:
385             case AVDTP_DELAY_REPORTING:
386                 break;
387             default:
388                 category_valid = 0;
389                 break;
390         }
391 
392         if (category_valid) {
393             registered_service_categories = store_bit16(registered_service_categories, category, 1);
394         }
395 
396         packet     += cap_len;
397         to_process -= cap_len;
398     }
399 
400     return registered_service_categories;
401 }
402 
403 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){
404     if (signaling_packet->offset) return;
405     bool basic_capabilities_only = false;
406     signaling_packet->message_type = AVDTP_RESPONSE_ACCEPT_MSG;
407     int i;
408 
409     signaling_packet->size = 0;
410     memset(signaling_packet->command, 0 , sizeof(signaling_packet->command));
411 
412     switch (identifier) {
413         case AVDTP_SI_GET_CAPABILITIES:
414             basic_capabilities_only = true;
415             break;
416         case AVDTP_SI_GET_ALL_CAPABILITIES:
417             break;
418         case AVDTP_SI_SET_CONFIGURATION:
419             signaling_packet->command[signaling_packet->size++] = signaling_packet->acp_seid << 2;
420             signaling_packet->command[signaling_packet->size++] = signaling_packet->int_seid << 2;
421             signaling_packet->message_type = AVDTP_CMD_MSG;
422             break;
423         case AVDTP_SI_RECONFIGURE:
424             signaling_packet->command[signaling_packet->size++] = signaling_packet->acp_seid << 2;
425             signaling_packet->message_type = AVDTP_CMD_MSG;
426             break;
427         default:
428             log_error("avdtp_prepare_capabilities wrong identifier %d", identifier);
429             break;
430     }
431 
432     for (i = AVDTP_MEDIA_TRANSPORT; i <= AVDTP_DELAY_REPORTING; i++){
433         int registered_category = get_bit16(service_categories, i);
434         if (!registered_category && (identifier == AVDTP_SI_SET_CONFIGURATION)){
435             // TODO: introduce bitmap of mandatory categories
436             if (i == AVDTP_MEDIA_TRANSPORT){
437                 registered_category = true;
438             }
439         }
440         // AVDTP_SI_GET_CAPABILITIES reports only basic capabilities (i.e., it skips non-basic categories)
441         if (basic_capabilities_only && !avdtp_is_basic_capability(i)){
442             registered_category = false;
443         }
444 
445         if (registered_category){
446             // service category
447             signaling_packet->command[signaling_packet->size++] = i;
448             signaling_packet->size += avdtp_pack_service_capabilities(signaling_packet->command + signaling_packet->size,
449                     sizeof(signaling_packet->command) - signaling_packet->size, capabilities, (avdtp_service_category_t) i);
450         }
451     }
452     signaling_packet->signal_identifier = (avdtp_signal_identifier_t)identifier;
453     signaling_packet->transaction_label = transaction_label;
454 }
455 
456 int avdtp_signaling_create_fragment(uint16_t cid, avdtp_signaling_packet_t * signaling_packet, uint8_t * out_buffer) {
457     int mtu = l2cap_get_remote_mtu_for_local_cid(cid);
458     int data_len = 0;
459 
460     uint16_t offset = signaling_packet->offset;
461     uint16_t pos = 1;
462 
463     if (offset == 0){
464         if (signaling_packet->size <= (mtu - 2)){
465             signaling_packet->packet_type = AVDTP_SINGLE_PACKET;
466             out_buffer[pos++] = signaling_packet->signal_identifier;
467             data_len = signaling_packet->size;
468         } else {
469             signaling_packet->packet_type = AVDTP_START_PACKET;
470             out_buffer[pos++] = (mtu + signaling_packet->size)/ (mtu-1);
471             out_buffer[pos++] = signaling_packet->signal_identifier;
472             data_len = mtu - 3;
473             signaling_packet->offset = data_len;
474         }
475     } else {
476         int remaining_bytes = signaling_packet->size - offset;
477         if (remaining_bytes <= (mtu - 1)){
478             signaling_packet->packet_type = AVDTP_END_PACKET;
479             data_len = remaining_bytes;
480             signaling_packet->offset = 0;
481         } else{
482             signaling_packet->packet_type = AVDTP_CONTINUE_PACKET;
483             data_len = mtu - 1;
484             signaling_packet->offset += data_len;
485         }
486     }
487     out_buffer[0] = avdtp_header(signaling_packet->transaction_label, signaling_packet->packet_type, signaling_packet->message_type);
488     (void)memcpy(out_buffer + pos, signaling_packet->command + offset,
489                  data_len);
490     pos += data_len;
491     return pos;
492 }
493 
494 
495 void avdtp_signaling_emit_connection_established(uint16_t avdtp_cid, bd_addr_t addr, hci_con_handle_t con_handle, uint8_t status) {
496     uint8_t event[14];
497     int pos = 0;
498     event[pos++] = HCI_EVENT_AVDTP_META;
499     event[pos++] = sizeof(event) - 2;
500     event[pos++] = AVDTP_SUBEVENT_SIGNALING_CONNECTION_ESTABLISHED;
501     little_endian_store_16(event, pos, avdtp_cid);
502     pos += 2;
503     reverse_bd_addr(addr,&event[pos]);
504     pos += 6;
505     little_endian_store_16(event, pos, con_handle);
506     pos += 2;
507     event[pos++] = status;
508     avdtp_emit_sink_and_source(event, pos);
509 }
510 
511 void avdtp_signaling_emit_connection_released(uint16_t avdtp_cid) {
512     uint8_t event[5];
513     int pos = 0;
514     event[pos++] = HCI_EVENT_AVDTP_META;
515     event[pos++] = sizeof(event) - 2;
516     event[pos++] = AVDTP_SUBEVENT_SIGNALING_CONNECTION_RELEASED;
517     little_endian_store_16(event, pos, avdtp_cid);
518     pos += 2;
519     avdtp_emit_sink_and_source(event, pos);
520 }
521 
522 void avdtp_signaling_emit_sep(uint16_t avdtp_cid, avdtp_sep_t sep) {
523     uint8_t event[9];
524     int pos = 0;
525     event[pos++] = HCI_EVENT_AVDTP_META;
526     event[pos++] = sizeof(event) - 2;
527     event[pos++] = AVDTP_SUBEVENT_SIGNALING_SEP_FOUND;
528     little_endian_store_16(event, pos, avdtp_cid);
529     pos += 2;
530     event[pos++] = sep.seid;
531     event[pos++] = sep.in_use;
532     event[pos++] = sep.media_type;
533     event[pos++] = sep.type;
534     avdtp_emit_sink_and_source(event, pos);
535 }
536 
537 void avdtp_signaling_emit_sep_done(uint16_t avdtp_cid) {
538     uint8_t event[5];
539     int pos = 0;
540     event[pos++] = HCI_EVENT_AVDTP_META;
541     event[pos++] = sizeof(event) - 2;
542     event[pos++] = AVDTP_SUBEVENT_SIGNALING_SEP_DICOVERY_DONE;
543     little_endian_store_16(event, pos, avdtp_cid);
544     pos += 2;
545     avdtp_emit_sink_and_source(event, pos);
546 }
547 
548 void avdtp_signaling_emit_accept(uint16_t avdtp_cid, uint8_t local_seid, avdtp_signal_identifier_t identifier, bool is_initiator) {
549     uint8_t event[8];
550     int pos = 0;
551     event[pos++] = HCI_EVENT_AVDTP_META;
552     event[pos++] = sizeof(event) - 2;
553     event[pos++] = AVDTP_SUBEVENT_SIGNALING_ACCEPT;
554     little_endian_store_16(event, pos, avdtp_cid);
555     pos += 2;
556     event[pos++] = local_seid;
557     event[pos++] = is_initiator ? 1 : 0;
558     event[pos++] = identifier;
559     avdtp_emit_sink_and_source(event, pos);
560 }
561 
562 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){
563     uint8_t event[8];
564     int pos = 0;
565     event[pos++] = HCI_EVENT_AVDTP_META;
566     event[pos++] = sizeof(event) - 2;
567     event[pos++] = AVDTP_SUBEVENT_SIGNALING_ACCEPT;
568     little_endian_store_16(event, pos, stream_endpoint->connection->avdtp_cid);
569     pos += 2;
570     event[pos++] = local_seid;
571     event[pos++] = is_initiator ? 1 : 0;
572     event[pos++] = identifier;
573 
574     btstack_packet_handler_t packet_handler = avdtp_packet_handler_for_stream_endpoint(stream_endpoint);
575     (*packet_handler)(HCI_EVENT_PACKET, 0, event, pos);
576 }
577 
578 void avdtp_signaling_emit_reject(uint16_t avdtp_cid, uint8_t local_seid, avdtp_signal_identifier_t identifier, bool is_initiator) {
579     uint8_t event[8];
580     int pos = 0;
581     event[pos++] = HCI_EVENT_AVDTP_META;
582     event[pos++] = sizeof(event) - 2;
583     event[pos++] = AVDTP_SUBEVENT_SIGNALING_REJECT;
584     little_endian_store_16(event, pos, avdtp_cid);
585     pos += 2;
586     event[pos++] = local_seid;
587     event[pos++] = is_initiator ? 1 : 0;
588     event[pos++] = identifier;
589     avdtp_emit_sink_and_source(event, pos);
590 }
591 
592 void avdtp_signaling_emit_general_reject(uint16_t avdtp_cid, uint8_t local_seid, avdtp_signal_identifier_t identifier, bool is_initiator) {
593     uint8_t event[8];
594     int pos = 0;
595     event[pos++] = HCI_EVENT_AVDTP_META;
596     event[pos++] = sizeof(event) - 2;
597     event[pos++] = AVDTP_SUBEVENT_SIGNALING_GENERAL_REJECT;
598     little_endian_store_16(event, pos, avdtp_cid);
599     pos += 2;
600     event[pos++] = local_seid;
601     event[pos++] = is_initiator ? 1 : 0;
602     event[pos++] = identifier;
603     avdtp_emit_sink_and_source(event, pos);
604 }
605 
606 static inline void
607 avdtp_signaling_emit_capability(uint8_t capability_subevent_id, uint16_t avdtp_cid, uint8_t remote_seid) {
608     uint8_t event[6];
609     int pos = 0;
610     event[pos++] = HCI_EVENT_AVDTP_META;
611     event[pos++] = sizeof(event) - 2;
612     event[pos++] = capability_subevent_id;
613     little_endian_store_16(event, pos, avdtp_cid);
614     pos += 2;
615     event[pos++] = remote_seid;
616     avdtp_emit_sink_and_source(event, pos);
617 }
618 
619 static void avdtp_signaling_emit_media_codec_sbc_capability(uint16_t avdtp_cid, uint8_t remote_seid, adtvp_media_codec_capabilities_t media_codec) {
620     const uint8_t * media_codec_information = media_codec.media_codec_information;
621     uint8_t event[14];
622     int pos = 0;
623     event[pos++] = HCI_EVENT_AVDTP_META;
624     event[pos++] = sizeof(event) - 2;
625     event[pos++] = AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_SBC_CAPABILITY;
626     little_endian_store_16(event, pos, avdtp_cid);
627     pos += 2;
628     event[pos++] = remote_seid;
629     event[pos++] = media_codec.media_type;
630     event[pos++] = media_codec_information[0] >> 4;
631     event[pos++] = media_codec_information[0] & 0x0F;
632     event[pos++] = media_codec_information[1] >> 4;
633     event[pos++] = (media_codec_information[1] & 0x0F) >> 2;
634     event[pos++] = media_codec_information[1] & 0x03;
635     event[pos++] = media_codec_information[2];
636     event[pos++] = media_codec_information[3];
637     avdtp_emit_sink_and_source(event, pos);
638 }
639 
640 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) {
641     const uint8_t * media_codec_information = media_codec.media_codec_information;
642     uint8_t event[15];
643     int pos = 0;
644     event[pos++] = HCI_EVENT_AVDTP_META;
645     event[pos++] = sizeof(event) - 2;
646     event[pos++] = AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_MPEG_AUDIO_CAPABILITY;
647     little_endian_store_16(event, pos, avdtp_cid);
648     pos += 2;
649     event[pos++] = remote_seid;
650     event[pos++] = media_codec.media_type;
651 
652     uint8_t layer_bitmap              =   media_codec_information[0] >> 5;
653     uint8_t crc                       =  (media_codec_information[0] >> 4) & 0x01;
654     uint8_t channel_mode_bitmap       =   media_codec_information[0] & 0x07;
655     uint8_t mpf                       =  (media_codec_information[1] >> 6) & 0x01;
656     uint8_t sampling_frequency_bitmap =   media_codec_information[1] & 0x3F;
657     uint8_t vbr                       =  (media_codec_information[2] >> 7) & 0x01;
658     uint16_t bit_rate_index_bitmap    = ((media_codec_information[3] & 0x3f) << 8) | media_codec.media_codec_information[4];
659 
660     event[pos++] = layer_bitmap;
661     event[pos++] = crc;
662     event[pos++] = channel_mode_bitmap;
663     event[pos++] = mpf;
664     event[pos++] = sampling_frequency_bitmap;
665     event[pos++] = vbr;
666     little_endian_store_16(event, pos, bit_rate_index_bitmap);           // bit rate index
667     pos += 2;
668     avdtp_emit_sink_and_source(event, pos);
669 }
670 
671 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) {
672     const uint8_t * media_codec_information = media_codec.media_codec_information;
673     uint8_t event[15];
674     int pos = 0;
675     event[pos++] = HCI_EVENT_AVDTP_META;
676     event[pos++] = sizeof(event) - 2;
677     event[pos++] = AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_MPEG_AAC_CAPABILITY;
678     little_endian_store_16(event, pos, avdtp_cid);
679     pos += 2;
680     event[pos++] = remote_seid;
681     event[pos++] = media_codec.media_type;
682 
683     uint8_t  object_type_bitmap        =   media_codec_information[0];
684     uint16_t sampling_frequency_bitmap =  (media_codec_information[1] << 4) | (media_codec_information[2] >> 4);
685     uint8_t  channels_bitmap           =  (media_codec_information[2] >> 2) & 0x03;
686     uint32_t bit_rate_bitmap           = ((media_codec_information[3] & 0x7f) << 16) | (media_codec_information[4] << 8) | media_codec_information[5];
687     uint8_t  vbr                       =   media_codec_information[3] >> 7;
688 
689     event[pos++] =  object_type_bitmap;
690     little_endian_store_16(event, pos, sampling_frequency_bitmap);
691     pos += 2;
692     event[pos++] = channels_bitmap;
693     little_endian_store_24(event, pos, bit_rate_bitmap);
694     pos += 3;
695     event[pos++] = vbr;
696     avdtp_emit_sink_and_source(event, pos);
697 }
698 
699 static void avdtp_signaling_emit_media_codec_atrac_capability(uint16_t avdtp_cid, uint8_t remote_seid, adtvp_media_codec_capabilities_t media_codec) {
700     const uint8_t * media_codec_information = media_codec.media_codec_information;
701     uint8_t event[16];
702     int pos = 0;
703     event[pos++] = HCI_EVENT_AVDTP_META;
704     pos++; // set later
705     event[pos++] = sizeof(event) - 2;
706     event[pos++] = AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_ATRAC_CAPABILITY;
707     little_endian_store_16(event, pos, avdtp_cid);
708     pos += 2;
709     event[pos++] = remote_seid;
710     event[pos++] = media_codec.media_type;
711 
712     uint8_t  version                   =  media_codec_information[0] >> 5;
713     uint8_t  channel_mode_bitmap       = (media_codec_information[0] >> 2) & 0x07;
714     uint16_t sampling_frequency_bitmap = (media_codec_information[1] >> 4) & 0x03;
715     uint8_t  vbr                       = (media_codec_information[1] >> 3) & 0x01;
716     uint16_t bit_rate_index_bitmap     = ((media_codec_information[1]) & 0x07) << 16 | (media_codec_information[2] << 8) | media_codec_information[3];
717     uint16_t maximum_sul               = (media_codec_information[4] << 8) | media_codec_information[5];
718 
719     event[pos++] = version;
720     event[pos++] = channel_mode_bitmap;
721     event[pos++] = sampling_frequency_bitmap;
722     event[pos++] = vbr;
723     little_endian_store_24(event, pos, bit_rate_index_bitmap);
724     pos += 3;
725     little_endian_store_16(event, pos, maximum_sul);
726     pos += 2;
727     event[1] = pos - 2;
728     avdtp_emit_sink_and_source(event, pos);
729 }
730 
731 static void avdtp_signaling_emit_media_codec_other_capability(uint16_t avdtp_cid, uint8_t remote_seid, adtvp_media_codec_capabilities_t media_codec) {
732     uint8_t event[MAX_MEDIA_CODEC_INFORMATION_LENGTH + 11];
733     int pos = 0;
734     event[pos++] = HCI_EVENT_AVDTP_META;
735     pos++; // set later
736     event[pos++] = sizeof(event) - 2;
737     event[pos++] = AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_OTHER_CAPABILITY;
738     little_endian_store_16(event, pos, avdtp_cid);
739     pos += 2;
740     event[pos++] = remote_seid;
741     event[pos++] = media_codec.media_type;
742     little_endian_store_16(event, pos, media_codec.media_codec_type);
743     pos += 2;
744     little_endian_store_16(event, pos, media_codec.media_codec_information_len);
745     pos += 2;
746     uint32_t media_codec_info_len = btstack_min(media_codec.media_codec_information_len, MAX_MEDIA_CODEC_INFORMATION_LENGTH);
747     (void)memcpy(event + pos, media_codec.media_codec_information, media_codec_info_len);
748     pos += media_codec_info_len;
749     event[1] = pos - 2;
750     avdtp_emit_sink_and_source(event, pos);
751 }
752 
753 static void
754 avdtp_signaling_emit_media_transport_capability(uint16_t avdtp_cid, uint8_t remote_seid) {
755 	avdtp_signaling_emit_capability(AVDTP_SUBEVENT_SIGNALING_MEDIA_TRANSPORT_CAPABILITY, avdtp_cid,
756 									remote_seid);
757 }
758 
759 static void avdtp_signaling_emit_reporting_capability(uint16_t avdtp_cid, uint8_t remote_seid) {
760 	avdtp_signaling_emit_capability(AVDTP_SUBEVENT_SIGNALING_REPORTING_CAPABILITY, avdtp_cid, remote_seid);
761 }
762 
763 static void
764 avdtp_signaling_emit_delay_reporting_capability(uint16_t avdtp_cid, uint8_t remote_seid) {
765 	avdtp_signaling_emit_capability(AVDTP_SUBEVENT_SIGNALING_DELAY_REPORTING_CAPABILITY, avdtp_cid,
766 									remote_seid);
767 }
768 
769 static void avdtp_signaling_emit_recovery_capability(uint16_t avdtp_cid, uint8_t remote_seid, avdtp_recovery_capabilities_t *recovery) {
770     uint8_t event[9];
771     int pos = 0;
772     event[pos++] = HCI_EVENT_AVDTP_META;
773     event[pos++] = sizeof(event) - 2;
774     event[pos++] = AVDTP_SUBEVENT_SIGNALING_RECOVERY_CAPABILITY;
775     little_endian_store_16(event, pos, avdtp_cid);
776     pos += 2;
777     event[pos++] = remote_seid;
778     event[pos++] = recovery->recovery_type;
779     event[pos++] = recovery->maximum_recovery_window_size;
780     event[pos++] = recovery->maximum_number_media_packets;
781     avdtp_emit_sink_and_source(event, pos);
782 }
783 
784 #define MAX_CONTENT_PROTECTION_VALUE_LEN 32
785 static void
786 avdtp_signaling_emit_content_protection_capability(uint16_t avdtp_cid, uint8_t remote_seid, adtvp_content_protection_t *content_protection) {
787     uint8_t event[10 + MAX_CONTENT_PROTECTION_VALUE_LEN];
788     int pos = 0;
789     event[pos++] = HCI_EVENT_AVDTP_META;
790     pos++; // set later
791     event[pos++] = sizeof(event) - 2;
792     event[pos++] = AVDTP_SUBEVENT_SIGNALING_CONTENT_PROTECTION_CAPABILITY;
793     little_endian_store_16(event, pos, avdtp_cid);
794     pos += 2;
795     event[pos++] = remote_seid;
796 
797     little_endian_store_16(event, pos, content_protection->cp_type);
798     pos += 2;
799 
800     // drop cp protection value if longer than expected
801     if (content_protection->cp_type_value_len <= MAX_CONTENT_PROTECTION_VALUE_LEN){
802         little_endian_store_16(event, pos, content_protection->cp_type_value_len);
803         pos += 2;
804         (void)memcpy(event + pos, content_protection->cp_type_value, content_protection->cp_type_value_len);
805         pos += content_protection->cp_type_value_len;
806     } else {
807         little_endian_store_16(event, pos, 0);
808         pos += 2;
809     }
810     event[1] = pos - 2;
811     avdtp_emit_sink_and_source(event, pos);
812 }
813 
814 
815 static void
816 avdtp_signaling_emit_header_compression_capability(uint16_t avdtp_cid, uint8_t remote_seid, avdtp_header_compression_capabilities_t *header_compression) {
817     uint8_t event[9];
818     int pos = 0;
819     event[pos++] = HCI_EVENT_AVDTP_META;
820     event[pos++] = sizeof(event) - 2;
821     event[pos++] = AVDTP_SUBEVENT_SIGNALING_HEADER_COMPRESSION_CAPABILITY;
822     little_endian_store_16(event, pos, avdtp_cid);
823     pos += 2;
824     event[pos++] = remote_seid;
825     event[pos++] = header_compression->back_ch;
826     event[pos++] = header_compression->media;
827     event[pos++] = header_compression->recovery;
828     avdtp_emit_sink_and_source(event, pos);
829 }
830 
831 static void
832 avdtp_signaling_emit_content_multiplexing_capability(uint16_t avdtp_cid, uint8_t remote_seid, avdtp_multiplexing_mode_capabilities_t *multiplexing_mode) {
833     uint8_t event[14];
834     int pos = 0;
835     event[pos++] = HCI_EVENT_AVDTP_META;
836     event[pos++] = sizeof(event) - 2;
837     event[pos++] = AVDTP_SUBEVENT_SIGNALING_MULTIPLEXING_CAPABILITY;
838     little_endian_store_16(event, pos, avdtp_cid);
839     pos += 2;
840     event[pos++] = remote_seid;
841 
842     event[pos++] = multiplexing_mode->fragmentation;
843     event[pos++] = multiplexing_mode->transport_identifiers_num;
844 
845     int i;
846     for (i = 0; i < 3; i++){
847         event[pos++] = multiplexing_mode->transport_session_identifiers[i];
848     }
849     for (i = 0; i < 3; i++){
850         event[pos++] = multiplexing_mode->tcid[i];
851     }
852     avdtp_emit_sink_and_source(event, pos);
853 }
854 
855 static void avdtp_signaling_emit_capability_done(uint16_t avdtp_cid, uint8_t remote_seid) {
856     uint8_t event[6];
857     int pos = 0;
858     event[pos++] = HCI_EVENT_AVDTP_META;
859     event[pos++] = sizeof(event) - 2;
860     event[pos++] = AVDTP_SUBEVENT_SIGNALING_CAPABILITIES_DONE;
861     little_endian_store_16(event, pos, avdtp_cid);
862     pos += 2;
863     event[pos++] = remote_seid;
864     avdtp_emit_sink_and_source(event, pos);
865 }
866 
867 static void avdtp_signaling_emit_media_codec_capability(uint16_t avdtp_cid, uint8_t remote_seid, adtvp_media_codec_capabilities_t media_codec){
868     switch (media_codec.media_codec_type){
869         case AVDTP_CODEC_SBC:
870             avdtp_signaling_emit_media_codec_sbc_capability(avdtp_cid, remote_seid, media_codec);
871             break;
872         case AVDTP_CODEC_MPEG_1_2_AUDIO:
873             avdtp_signaling_emit_media_codec_mpeg_audio_capability(avdtp_cid, remote_seid, media_codec);
874             break;
875         case AVDTP_CODEC_MPEG_2_4_AAC:
876             avdtp_signaling_emit_media_codec_mpeg_aac_capability(avdtp_cid, remote_seid, media_codec);
877             break;
878         case AVDTP_CODEC_ATRAC_FAMILY:
879             avdtp_signaling_emit_media_codec_atrac_capability(avdtp_cid, remote_seid, media_codec);
880             break;
881         default:
882             avdtp_signaling_emit_media_codec_other_capability(avdtp_cid, remote_seid, media_codec);
883             break;
884     }
885 }
886 
887 // emit events for all capabilities incl. final done event
888 void avdtp_signaling_emit_capabilities(uint16_t avdtp_cid, uint8_t remote_seid, avdtp_capabilities_t *capabilities,
889 									   uint16_t registered_service_categories) {
890     if (get_bit16(registered_service_categories, AVDTP_MEDIA_CODEC)){
891         avdtp_signaling_emit_media_codec_capability(avdtp_cid, remote_seid, capabilities->media_codec);
892     }
893 
894     if (get_bit16(registered_service_categories, AVDTP_MEDIA_TRANSPORT)){
895 		avdtp_signaling_emit_media_transport_capability(avdtp_cid, remote_seid);
896     }
897     if (get_bit16(registered_service_categories, AVDTP_REPORTING)){
898 		avdtp_signaling_emit_reporting_capability(avdtp_cid, remote_seid);
899     }
900     if (get_bit16(registered_service_categories, AVDTP_RECOVERY)){
901 		avdtp_signaling_emit_recovery_capability(avdtp_cid, remote_seid, &capabilities->recovery);
902     }
903     if (get_bit16(registered_service_categories, AVDTP_CONTENT_PROTECTION)){
904 		avdtp_signaling_emit_content_protection_capability(avdtp_cid, remote_seid,
905 														   &capabilities->content_protection);
906     }
907     if (get_bit16(registered_service_categories, AVDTP_HEADER_COMPRESSION)){
908 		avdtp_signaling_emit_header_compression_capability(avdtp_cid, remote_seid,
909 														   &capabilities->header_compression);
910     }
911     if (get_bit16(registered_service_categories, AVDTP_MULTIPLEXING)){
912 		avdtp_signaling_emit_content_multiplexing_capability(avdtp_cid, remote_seid,
913 															 &capabilities->multiplexing_mode);
914     }
915     if (get_bit16(registered_service_categories, AVDTP_DELAY_REPORTING)){
916 		avdtp_signaling_emit_delay_reporting_capability(avdtp_cid, remote_seid);
917     }
918 	avdtp_signaling_emit_capability_done(avdtp_cid, remote_seid);
919 }
920 
921 static void
922 avdtp_signaling_emit_media_codec_sbc(avdtp_stream_endpoint_t *stream_endpoint, uint16_t avdtp_cid, uint8_t reconfigure,
923                                      avdtp_media_type_t media_type, const uint8_t *media_codec_information) {
924 
925     btstack_packet_handler_t packet_handler = avdtp_packet_handler_for_stream_endpoint(stream_endpoint);
926     uint8_t local_seid = avdtp_local_seid(stream_endpoint);
927     uint8_t remote_seid = avdtp_remote_seid(stream_endpoint);
928 
929     uint8_t event[16 + 2];
930     int pos = 0;
931     event[pos++] = HCI_EVENT_AVDTP_META;
932     event[pos++] = sizeof(event) - 2;
933 
934     event[pos++] = AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_SBC_CONFIGURATION;
935     little_endian_store_16(event, pos, avdtp_cid);
936     pos += 2;
937     event[pos++] = local_seid;
938     event[pos++] = remote_seid;
939     event[pos++] = reconfigure;
940 
941 
942     uint8_t sampling_frequency_bitmap = media_codec_information[0] >> 4;
943     uint8_t channel_mode_bitmap = media_codec_information[0] & 0x0F;
944     uint8_t block_length_bitmap = media_codec_information[1] >> 4;
945     uint8_t subbands_bitmap = (media_codec_information[1] & 0x0F) >> 2;
946 
947     uint8_t num_channels = 0;
948     avdtp_channel_mode_t channel_mode;
949 
950     if (channel_mode_bitmap & AVDTP_SBC_JOINT_STEREO){
951         channel_mode = AVDTP_CHANNEL_MODE_JOINT_STEREO;
952         num_channels = 2;
953     } else if (channel_mode_bitmap & AVDTP_SBC_STEREO){
954         channel_mode = AVDTP_CHANNEL_MODE_STEREO;
955         num_channels = 2;
956     } else if (channel_mode_bitmap & AVDTP_SBC_DUAL_CHANNEL){
957         channel_mode = AVDTP_CHANNEL_MODE_DUAL_CHANNEL;
958         num_channels = 2;
959     } else {
960         channel_mode = AVDTP_CHANNEL_MODE_MONO;
961         num_channels = 1;
962     }
963 
964     uint16_t sampling_frequency = 0;
965     if (sampling_frequency_bitmap & AVDTP_SBC_48000) {
966         sampling_frequency = 48000;
967     } else if (sampling_frequency_bitmap & AVDTP_SBC_44100) {
968         sampling_frequency = 44100;
969     } else if (sampling_frequency_bitmap & AVDTP_SBC_32000) {
970         sampling_frequency = 32000;
971     } else if (sampling_frequency_bitmap & AVDTP_SBC_16000) {
972         sampling_frequency = 16000;
973     }
974 
975     uint8_t subbands = 0;
976     if (subbands_bitmap & AVDTP_SBC_SUBBANDS_8){
977         subbands = 8;
978     } else if (subbands_bitmap & AVDTP_SBC_SUBBANDS_4){
979         subbands = 4;
980     }
981 
982     uint8_t block_length = 0;
983     if (block_length_bitmap & AVDTP_SBC_BLOCK_LENGTH_16){
984         block_length = 16;
985     } else if (block_length_bitmap & AVDTP_SBC_BLOCK_LENGTH_12){
986         block_length = 12;
987     } else if (block_length_bitmap & AVDTP_SBC_BLOCK_LENGTH_8){
988         block_length = 8;
989     } else if (block_length_bitmap & AVDTP_SBC_BLOCK_LENGTH_4){
990         block_length = 4;
991     }
992 
993     event[pos++] = media_type;
994     little_endian_store_16(event, pos, sampling_frequency);
995     pos += 2;
996 
997     event[pos++] = (uint8_t) channel_mode;
998     event[pos++] = num_channels;
999     event[pos++] = block_length;
1000     event[pos++] = subbands;
1001     event[pos++] = media_codec_information[1] & 0x03;
1002     event[pos++] = media_codec_information[2];
1003     event[pos++] = media_codec_information[3];
1004     (*packet_handler)(HCI_EVENT_PACKET, 0, event, pos);
1005 }
1006 
1007 static void
1008 avdtp_signaling_emit_media_codec_mpeg_audio_configuration(avdtp_stream_endpoint_t *stream_endpoint, uint16_t avdtp_cid,
1009                                                           uint8_t reconfigure, avdtp_media_type_t media_type,
1010                                                           const uint8_t *media_codec_information) {
1011 
1012     btstack_packet_handler_t packet_handler = avdtp_packet_handler_for_stream_endpoint(stream_endpoint);
1013     uint8_t local_seid = avdtp_local_seid(stream_endpoint);
1014     uint8_t remote_seid = avdtp_remote_seid(stream_endpoint);
1015 
1016     uint8_t event[18];
1017     int pos = 0;
1018     event[pos++] = HCI_EVENT_AVDTP_META;
1019     event[pos++] = sizeof(event) - 2;
1020 
1021     event[pos++] = AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_MPEG_AUDIO_CONFIGURATION;
1022     little_endian_store_16(event, pos, avdtp_cid);
1023     pos += 2;
1024     event[pos++] = local_seid;
1025     event[pos++] = remote_seid;
1026     event[pos++] = reconfigure;
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++] = media_type;
1085     event[pos++] = (uint8_t) layer;
1086     event[pos++] = crc;
1087     event[pos++] = (uint8_t) channel_mode;
1088     event[pos++] = num_channels;
1089     event[pos++] = mpf;
1090     little_endian_store_16(event, pos, sampling_frequency);
1091     pos += 2;
1092     event[pos++] = vbr;
1093     event[pos++] = bitrate_index;
1094 
1095     (*packet_handler)(HCI_EVENT_PACKET, 0, event, pos);
1096 }
1097 
1098 
1099 static void
1100 avdtp_signaling_emit_media_codec_mpeg_aac_configuration(avdtp_stream_endpoint_t *stream_endpoint, uint16_t avdtp_cid,
1101                                                         uint8_t reconfigure, avdtp_media_type_t media_type,
1102                                                         const uint8_t *media_codec_information) {
1103 
1104     btstack_packet_handler_t packet_handler = avdtp_packet_handler_for_stream_endpoint(stream_endpoint);
1105     uint8_t local_seid = avdtp_local_seid(stream_endpoint);
1106     uint8_t remote_seid = avdtp_remote_seid(stream_endpoint);
1107 
1108     uint8_t event[18];
1109     int pos = 0;
1110     event[pos++] = HCI_EVENT_AVDTP_META;
1111     event[pos++] = sizeof(event) - 2;
1112 
1113     event[pos++] = AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_MPEG_AAC_CONFIGURATION;
1114     little_endian_store_16(event, pos, avdtp_cid);
1115     pos += 2;
1116     event[pos++] = local_seid;
1117     event[pos++] = remote_seid;
1118     event[pos++] = reconfigure;
1119 
1120     uint8_t  object_type_bitmap        =   media_codec_information[0];
1121     uint16_t sampling_frequency_bitmap =  (media_codec_information[1] << 4) | (media_codec_information[2] >> 4);
1122     uint8_t  channels_bitmap           =  (media_codec_information[2] >> 2) & 0x03;
1123     uint8_t  vbr                       =   media_codec_information[3] >> 7;
1124     uint32_t bit_rate                  = ((media_codec_information[3] & 0x7f) << 16) | (media_codec_information[4] << 8) | media_codec_information[5];
1125 
1126     uint8_t object_type = 0;
1127     if (object_type_bitmap & 0x80){
1128         object_type = AVDTP_AAC_MPEG2_LC;
1129     } else if (object_type_bitmap & 0x40){
1130         object_type = AVDTP_AAC_MPEG4_LC;
1131     } else if (object_type_bitmap & 0x020){
1132         object_type = AVDTP_AAC_MPEG4_LTP;
1133     } else if (object_type_bitmap & 0x010){
1134         object_type = AVDTP_AAC_MPEG4_SCALABLE;
1135     }
1136 
1137     uint32_t sampling_frequency = 0;
1138     uint8_t i;
1139     const uint32_t aac_sampling_frequency_table[] = {
1140         96000, 88200, 64000, 48000, 44100, 32000, 24000, 22050, 16000, 12000, 11025, 8000
1141     };
1142     for (i=0;i<12;i++){
1143         if (sampling_frequency_bitmap & (1U << i)) {
1144             sampling_frequency = aac_sampling_frequency_table[i];
1145         }
1146     }
1147 
1148     uint8_t num_channels = 0;
1149     if (channels_bitmap & 0x02){
1150         num_channels = 1;
1151     } else if (channels_bitmap & 0x01){
1152         num_channels = 2;
1153     }
1154 
1155     event[pos++] = media_type;
1156     event[pos++] = object_type;
1157     little_endian_store_24(event, pos, sampling_frequency);
1158     pos += 3;
1159     event[pos++] = num_channels;
1160     little_endian_store_24(event, pos, bit_rate);
1161     pos += 3;
1162     event[pos++] = vbr;
1163 
1164     (*packet_handler)(HCI_EVENT_PACKET, 0, event, pos);
1165 }
1166 
1167 static void
1168 avdtp_signaling_emit_media_codec_atrac_configuration(avdtp_stream_endpoint_t *stream_endpoint, uint16_t avdtp_cid,
1169                                                      uint8_t reconfigure, avdtp_media_type_t media_type,
1170                                                      const uint8_t *media_codec_information) {
1171 
1172     btstack_packet_handler_t packet_handler = avdtp_packet_handler_for_stream_endpoint(stream_endpoint);
1173     uint8_t local_seid = avdtp_local_seid(stream_endpoint);
1174     uint8_t remote_seid = avdtp_remote_seid(stream_endpoint);
1175 
1176     uint8_t event[18];
1177     int pos = 0;
1178     event[pos++] = HCI_EVENT_AVDTP_META;
1179     event[pos++] = sizeof(event) - 2;
1180 
1181     event[pos++] = AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_ATRAC_CONFIGURATION;
1182     little_endian_store_16(event, pos, avdtp_cid);
1183     pos += 2;
1184     event[pos++] = local_seid;
1185     event[pos++] = remote_seid;
1186     event[pos++] = reconfigure;
1187 
1188     avdtp_atrac_version_t  version     = (avdtp_atrac_version_t) (media_codec_information[0] >> 5);
1189     uint8_t  channel_mode_bitmap       = (media_codec_information[0] >> 2) & 0x07;
1190     uint16_t sampling_frequency_bitmap = (media_codec_information[1] >> 4) & 0x03;
1191     uint8_t  vbr                       = (media_codec_information[1] >> 3) & 0x01;
1192     uint16_t bit_rate_index_bitmap     = ((media_codec_information[1]) & 0x07) << 16 | (media_codec_information[2] << 8) | media_codec_information[3];
1193     uint16_t maximum_sul               = (media_codec_information[4] << 8) | media_codec_information[5];
1194 
1195     uint8_t num_channels = 0;
1196     avdtp_channel_mode_t channel_mode = AVDTP_CHANNEL_MODE_JOINT_STEREO;
1197     if (channel_mode_bitmap & 0x04){
1198         num_channels = 1;
1199         channel_mode = AVDTP_CHANNEL_MODE_MONO;
1200     } else if (channel_mode_bitmap & 0x02){
1201         num_channels = 2;
1202         channel_mode = AVDTP_CHANNEL_MODE_DUAL_CHANNEL;
1203     } else if (channel_mode_bitmap & 0x01){
1204         num_channels = 2;
1205         channel_mode = AVDTP_CHANNEL_MODE_JOINT_STEREO;
1206     }
1207 
1208     uint16_t sampling_frequency = 0;
1209     if (sampling_frequency_bitmap & 0x02){
1210         sampling_frequency = 44100;
1211     } else if (sampling_frequency_bitmap & 0x01){
1212         sampling_frequency = 48000;
1213     }
1214 
1215     // bit 0 = index 0x18, bit 19 = index 0
1216     uint8_t bit_rate_index = 0;
1217     uint8_t i;
1218     for (i=0;i <= 19;i++){
1219         if (bit_rate_index_bitmap & (1U << i)) {
1220             bit_rate_index = 18 - i;
1221         }
1222     }
1223 
1224     event[pos++] = media_type;
1225     event[pos++] = (uint8_t) version;
1226     event[pos++] = (uint8_t) channel_mode;
1227     event[pos++] = num_channels;
1228     little_endian_store_16(event, pos, sampling_frequency);
1229     pos += 2;
1230     event[pos++] = vbr;
1231     event[pos++] = bit_rate_index;
1232     little_endian_store_16(event, pos, maximum_sul);
1233     pos += 2;
1234 
1235     (*packet_handler)(HCI_EVENT_PACKET, 0, event, pos);
1236 }
1237 
1238 static void avdtp_signaling_emit_media_codec_other_configuration(avdtp_stream_endpoint_t *stream_endpoint, uint16_t avdtp_cid,
1239                                                    uint8_t reconfigure, adtvp_media_codec_capabilities_t *media_codec) {
1240 
1241     btstack_packet_handler_t packet_handler = avdtp_packet_handler_for_stream_endpoint(stream_endpoint);
1242     uint8_t local_seid = avdtp_local_seid(stream_endpoint);
1243     uint8_t remote_seid = avdtp_remote_seid(stream_endpoint);
1244 
1245     uint8_t event[MAX_MEDIA_CODEC_INFORMATION_LENGTH + 13];
1246     int pos = 0;
1247     event[pos++] = HCI_EVENT_AVDTP_META;
1248     pos++;  // set later
1249     event[pos++] = sizeof(event) - 2;
1250     event[pos++] = AVDTP_SUBEVENT_SIGNALING_MEDIA_CODEC_OTHER_CONFIGURATION;
1251     little_endian_store_16(event, pos, avdtp_cid);
1252     pos += 2;
1253     event[pos++] = local_seid;
1254     event[pos++] = remote_seid;
1255     event[pos++] = reconfigure;
1256     event[pos++] = media_codec->media_type;
1257     little_endian_store_16(event, pos, media_codec->media_codec_type);
1258     pos += 2;
1259     little_endian_store_16(event, pos, media_codec->media_codec_information_len);
1260     pos += 2;
1261     uint16_t media_codec_len = btstack_min(MAX_MEDIA_CODEC_INFORMATION_LENGTH, media_codec->media_codec_information_len);
1262     (void)memcpy(event + pos, media_codec->media_codec_information, media_codec_len);
1263     pos += media_codec_len;
1264     event[1] = pos - 2;
1265     (*packet_handler)(HCI_EVENT_PACKET, 0, event, pos);
1266 }
1267 
1268 void avdtp_signaling_emit_delay(uint16_t avdtp_cid, uint8_t local_seid, uint16_t delay) {
1269     uint8_t event[8];
1270     int pos = 0;
1271     event[pos++] = HCI_EVENT_AVDTP_META;
1272     event[pos++] = sizeof(event) - 2;
1273     event[pos++] = AVDTP_SUBEVENT_SIGNALING_DELAY_REPORT;
1274     little_endian_store_16(event, pos, avdtp_cid);
1275     pos += 2;
1276     event[pos++] = local_seid;
1277     little_endian_store_16(event, pos, delay);
1278     pos += 2;
1279     avdtp_emit_source(event, sizeof(event));
1280 }
1281 
1282 void avdtp_signaling_emit_configuration(avdtp_stream_endpoint_t *stream_endpoint, uint16_t avdtp_cid, uint8_t reconfigure,
1283                                    avdtp_capabilities_t *configuration, uint16_t configured_service_categories) {
1284 
1285     if (get_bit16(configured_service_categories, AVDTP_MEDIA_CODEC)){
1286         switch (configuration->media_codec.media_codec_type){
1287             case AVDTP_CODEC_SBC: {
1288                 avdtp_signaling_emit_media_codec_sbc(stream_endpoint, avdtp_cid, reconfigure,
1289                                                      configuration->media_codec.media_type,
1290                                                      configuration->media_codec.media_codec_information);
1291             }
1292                 break;
1293             case AVDTP_CODEC_MPEG_1_2_AUDIO:
1294                 avdtp_signaling_emit_media_codec_mpeg_audio_configuration(
1295                         stream_endpoint, avdtp_cid, reconfigure,
1296                         configuration->media_codec.media_type,
1297                         configuration->media_codec.media_codec_information);
1298                 break;
1299             case AVDTP_CODEC_MPEG_2_4_AAC:
1300                 avdtp_signaling_emit_media_codec_mpeg_aac_configuration(
1301                         stream_endpoint, avdtp_cid, reconfigure,
1302                         configuration->media_codec.media_type,
1303                         configuration->media_codec.media_codec_information);
1304                 break;
1305             case AVDTP_CODEC_ATRAC_FAMILY:
1306                 avdtp_signaling_emit_media_codec_atrac_configuration(
1307                         stream_endpoint, avdtp_cid, reconfigure,
1308                         configuration->media_codec.media_type,
1309                         configuration->media_codec.media_codec_information);
1310                 break;
1311             default:
1312                 avdtp_signaling_emit_media_codec_other_configuration(stream_endpoint, avdtp_cid, reconfigure, &configuration->media_codec);
1313                 break;
1314         }
1315     }
1316 }
1317 
1318 void avdtp_streaming_emit_connection_established(avdtp_stream_endpoint_t *stream_endpoint, uint8_t status) {
1319     uint8_t event[14];
1320     int pos = 0;
1321     event[pos++] = HCI_EVENT_AVDTP_META;
1322     event[pos++] = sizeof(event) - 2;
1323     event[pos++] = AVDTP_SUBEVENT_STREAMING_CONNECTION_ESTABLISHED;
1324     little_endian_store_16(event, pos, stream_endpoint->connection->avdtp_cid);
1325     pos += 2;
1326     reverse_bd_addr(stream_endpoint->connection->remote_addr, &event[pos]);
1327     pos += 6;
1328     event[pos++] = avdtp_local_seid(stream_endpoint);
1329     event[pos++] = avdtp_remote_seid(stream_endpoint);
1330     event[pos++] = status;
1331 
1332     btstack_packet_handler_t packet_handler = avdtp_packet_handler_for_stream_endpoint(stream_endpoint);
1333     (*packet_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event));
1334 }
1335 
1336 void avdtp_streaming_emit_connection_released(avdtp_stream_endpoint_t *stream_endpoint, uint16_t avdtp_cid, uint8_t local_seid) {
1337     uint8_t event[6];
1338     int pos = 0;
1339     event[pos++] = HCI_EVENT_AVDTP_META;
1340     event[pos++] = sizeof(event) - 2;
1341     event[pos++] = AVDTP_SUBEVENT_STREAMING_CONNECTION_RELEASED;
1342     little_endian_store_16(event, pos, avdtp_cid);
1343     pos += 2;
1344     event[pos++] = local_seid;
1345 
1346     btstack_packet_handler_t packet_handler = avdtp_packet_handler_for_stream_endpoint(stream_endpoint);
1347     (*packet_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event));
1348 }
1349 
1350 void avdtp_streaming_emit_can_send_media_packet_now(avdtp_stream_endpoint_t *stream_endpoint, uint16_t sequence_number) {
1351     uint8_t event[8];
1352     int pos = 0;
1353     event[pos++] = HCI_EVENT_AVDTP_META;
1354     event[pos++] = sizeof(event) - 2;
1355     event[pos++] = AVDTP_SUBEVENT_STREAMING_CAN_SEND_MEDIA_PACKET_NOW;
1356     little_endian_store_16(event, pos, stream_endpoint->connection->avdtp_cid);
1357     pos += 2;
1358     event[pos++] = avdtp_local_seid(stream_endpoint);
1359     little_endian_store_16(event, pos, sequence_number);
1360     pos += 2;
1361 
1362     btstack_packet_handler_t packet_handler = avdtp_packet_handler_for_stream_endpoint(stream_endpoint);
1363     (*packet_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event));
1364 }
1365 
1366 uint8_t avdtp_request_can_send_now_acceptor(avdtp_connection_t *connection) {
1367     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1368     connection->wait_to_send_acceptor = true;
1369     l2cap_request_can_send_now_event(connection->l2cap_signaling_cid);
1370     return ERROR_CODE_SUCCESS;
1371 }
1372 
1373 uint8_t avdtp_request_can_send_now_initiator(avdtp_connection_t *connection) {
1374     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1375     connection->wait_to_send_initiator = true;
1376     l2cap_request_can_send_now_event(connection->l2cap_signaling_cid);
1377     return ERROR_CODE_SUCCESS;
1378 }
1379 
1380 uint8_t avdtp_local_seid(avdtp_stream_endpoint_t * stream_endpoint){
1381     if (!stream_endpoint) return 0;
1382     return stream_endpoint->sep.seid;
1383 
1384 }
1385 
1386 uint8_t avdtp_remote_seid(avdtp_stream_endpoint_t * stream_endpoint){
1387     if (!stream_endpoint) return AVDTP_INVALID_SEP_SEID;
1388     return stream_endpoint->remote_sep.seid;
1389 }
1390 
1391 // helper for A2DP
1392 
1393 void a2dp_replace_subevent_id_and_emit_cmd(btstack_packet_handler_t callback, uint8_t * packet, uint16_t size, uint8_t subevent_id){
1394     UNUSED(size);
1395     btstack_assert(callback != NULL);
1396     // cache orig event and subevent id
1397     uint8_t orig_event_id    = packet[0];
1398     uint8_t orig_subevent_id = packet[2];
1399     // execute callback
1400     packet[0] = HCI_EVENT_A2DP_META;
1401     packet[2] = subevent_id;
1402     (*callback)(HCI_EVENT_PACKET, 0, packet, size);
1403     // restore id
1404     packet[0] = orig_event_id;
1405     packet[2] = orig_subevent_id;
1406 }
1407 
1408 void a2dp_emit_stream_event(btstack_packet_handler_t callback, uint16_t cid, uint8_t local_seid, uint8_t subevent_id){
1409     uint8_t event[6];
1410     int pos = 0;
1411     event[pos++] = HCI_EVENT_A2DP_META;
1412     event[pos++] = sizeof(event) - 2;
1413     event[pos++] = subevent_id;
1414     little_endian_store_16(event, pos, cid);
1415     pos += 2;
1416     event[pos++] = local_seid;
1417     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
1418 }
1419 
1420 // helper to set/get configuration
1421 void avdtp_config_sbc_set_sampling_frequency(uint8_t * config, uint16_t sampling_frequency_hz){
1422     avdtp_sbc_sampling_frequency_t sampling_frequency;
1423     switch (sampling_frequency_hz){
1424         case 16000:
1425             sampling_frequency = AVDTP_SBC_16000;
1426             break;
1427         case 32000:
1428             sampling_frequency = AVDTP_SBC_32000;
1429             break;
1430         case 48000:
1431             sampling_frequency = AVDTP_SBC_48000;
1432             break;
1433         default:
1434             sampling_frequency = AVDTP_SBC_44100;
1435             break;
1436     }
1437     config[0] = (((uint8_t) sampling_frequency) << 4) | (config[0] & 0x0f);
1438 }
1439 
1440 void avdtp_config_sbc_store(uint8_t * config, const avdtp_configuration_sbc_t * configuration){
1441     avdtp_sbc_channel_mode_t sbc_channel_mode;
1442     switch (configuration->channel_mode){
1443         case AVDTP_CHANNEL_MODE_MONO:
1444             sbc_channel_mode = AVDTP_SBC_MONO;
1445             break;
1446         case AVDTP_CHANNEL_MODE_DUAL_CHANNEL:
1447             sbc_channel_mode = AVDTP_SBC_DUAL_CHANNEL;
1448             break;
1449         case AVDTP_CHANNEL_MODE_STEREO:
1450             sbc_channel_mode = AVDTP_SBC_STEREO;
1451             break;
1452         default:
1453             sbc_channel_mode = AVDTP_SBC_JOINT_STEREO;
1454             break;
1455     }
1456     config[0] = (uint8_t) sbc_channel_mode;
1457     config[1] = (configuration->block_length << 4) | (configuration->subbands << 2) | configuration->allocation_method;
1458     config[2] = configuration-> min_bitpool_value;
1459     config[3] = configuration->max_bitpool_value;
1460     avdtp_config_sbc_set_sampling_frequency(config, configuration->sampling_frequency);
1461 }
1462 
1463 void avdtp_config_mpeg_audio_set_sampling_frequency(uint8_t * config, uint16_t sampling_frequency_hz) {
1464     uint8_t sampling_frequency_index = 0;
1465     switch (sampling_frequency_hz){
1466         case 16000:
1467             sampling_frequency_index = 5;
1468             break;
1469         case 22040:
1470             sampling_frequency_index = 4;
1471             break;
1472         case 24000:
1473             sampling_frequency_index = 3;
1474             break;
1475         case 32000:
1476             sampling_frequency_index = 2;
1477             break;
1478         case 44100:
1479             sampling_frequency_index = 1;
1480             break;
1481         case 48000:
1482             sampling_frequency_index = 0;
1483             break;
1484         default:
1485             btstack_assert(false);
1486             break;
1487     }
1488     config[1] = (config[1] & 0xC0) | (1 << sampling_frequency_index);
1489 }
1490 
1491 void avdtp_config_mpeg_audio_store(uint8_t * config, const avdtp_configuration_mpeg_audio_t * configuration){
1492 
1493     config[0] = (1 << (7 - (configuration->layer - AVDTP_MPEG_LAYER_1))) | ((configuration->crc & 0x01) << 4) | (1 << (configuration->channel_mode - AVDTP_CHANNEL_MODE_MONO));
1494     config[1] = ((configuration->media_payload_format & 0x01) << 6) ;
1495     uint16_t bit_rate_mask = 1 << configuration->bit_rate_index;
1496     config[2] = ((configuration->vbr & 0x01) << 7) | ((bit_rate_mask >> 8) & 0x3f);
1497     config[3] = bit_rate_mask & 0xff;
1498     avdtp_config_mpeg_audio_set_sampling_frequency(config, configuration->sampling_frequency);
1499 }
1500 
1501 
1502 void avdtp_config_mpeg_aac_set_sampling_frequency(uint8_t * config, uint16_t sampling_frequency_hz) {
1503     uint16_t sampling_frequency_bitmap = 0;
1504     uint8_t i;
1505     const uint32_t aac_sampling_frequency_table[] = {
1506             96000, 88200, 64000, 48000, 44100, 32000, 24000, 22050, 16000, 12000, 11025, 8000
1507     };
1508     for (i=0;i<12;i++){
1509         if (sampling_frequency_hz == aac_sampling_frequency_table[i]){
1510             sampling_frequency_bitmap = 1 << i;
1511             break;
1512         }
1513     }
1514     config[1] = sampling_frequency_bitmap >> 4;
1515     config[2] = ((sampling_frequency_bitmap & 0x0f) << 4) | (config[2] & 0x0f);
1516 }
1517 
1518 void avdtp_config_mpeg_aac_store(uint8_t * config, const avdtp_configuration_mpeg_aac_t * configuration) {
1519     config[0] = 1 << (7 -(configuration->object_type - AVDTP_AAC_MPEG2_LC));
1520     uint8_t channels_bitmap = 0;
1521     switch (configuration->channels){
1522         case 1:
1523             channels_bitmap = 0x02;
1524             break;
1525         case 2:
1526             channels_bitmap = 0x01;
1527             break;
1528         default:
1529             break;
1530     }
1531     config[2] = channels_bitmap << 2;
1532     config[3] = ((configuration->vbr & 0x01) << 7) | ((configuration->bit_rate >> 16) & 0x7f);
1533     config[4] = (configuration->bit_rate >> 8) & 0xff;
1534     config[5] =  configuration->bit_rate & 0xff;
1535     avdtp_config_mpeg_aac_set_sampling_frequency(config, configuration->sampling_frequency);
1536 }
1537 
1538 void avdtp_config_atrac_set_sampling_frequency(uint8_t * config, uint16_t sampling_frequency_hz) {
1539     uint8_t fs_bitmap = 0;
1540     switch (sampling_frequency_hz){
1541         case 44100:
1542             fs_bitmap = 2;
1543             break;
1544         case 48000:
1545             fs_bitmap = 1;
1546             break;
1547         default:
1548             break;
1549     }
1550     config[1] = (fs_bitmap << 4) | (config[1] & 0x0F);
1551 }
1552 
1553 void avdtp_config_atrac_store(uint8_t * config, const avdtp_configuration_atrac_t * configuration){
1554     uint8_t channel_mode_bitmap = 0;
1555     switch (configuration->channel_mode){
1556         case AVDTP_CHANNEL_MODE_MONO:
1557             channel_mode_bitmap = 4;
1558             break;
1559         case AVDTP_CHANNEL_MODE_DUAL_CHANNEL:
1560             channel_mode_bitmap = 2;
1561             break;
1562         case AVDTP_CHANNEL_MODE_JOINT_STEREO:
1563             channel_mode_bitmap = 1;
1564             break;
1565         default:
1566             break;
1567     }
1568     config[0] = ((configuration->version - AVDTP_ATRAC_VERSION_1 + 1) << 5) | (channel_mode_bitmap << 2);
1569     uint32_t bit_rate_bitmap = 1 << (0x18 - configuration->bit_rate_index);
1570     config[1] = ((configuration->vbr & 0x01) << 3) | ((bit_rate_bitmap >> 16) & 0x07);
1571     config[2] = (bit_rate_bitmap >> 8) & 0xff;
1572     config[3] = bit_rate_bitmap & 0xff;
1573     config[4] = configuration->maximum_sul >> 8;
1574     config[5] = configuration->maximum_sul & 0xff;
1575     config[6] = 0;
1576     avdtp_config_atrac_set_sampling_frequency(config, configuration->sampling_frequency);
1577 }
1578