xref: /btstack/src/classic/avrcp_controller.c (revision 2ac1dc76c9f11326904f6859da1d08322744e245)
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__ "avrcp_controller.c"
39 
40 #include <stdint.h>
41 #include <string.h>
42 #include <inttypes.h>
43 
44 #include "classic/avrcp.h"
45 #include "classic/avrcp_controller.h"
46 
47 #include "bluetooth_sdp.h"
48 #include "btstack_debug.h"
49 #include "btstack_event.h"
50 #include "btstack_util.h"
51 #include "l2cap.h"
52 
53 #define AVRCP_CMD_BUFFER_SIZE 30
54 
55 // made public in avrcp_controller.h
56 avrcp_context_t avrcp_controller_context;
57 
58 static uint8_t avrcp_controller_calc_next_transaction_label(uint8_t current_transaction_label){
59     current_transaction_label++;
60     if (current_transaction_label == 16){
61         current_transaction_label = 1;
62     }
63     return current_transaction_label;
64 }
65 
66 static uint8_t avrcp_controller_get_next_transaction_label(avrcp_connection_t * connection){
67     connection->transaction_id_counter = avrcp_controller_calc_next_transaction_label(connection->transaction_id_counter);
68     return connection->transaction_id_counter;
69 }
70 
71 static bool avrcp_controller_is_transaction_id_valid(avrcp_connection_t * connection, uint8_t transaction_id){
72     uint8_t delta = ((int8_t) transaction_id - connection->last_confirmed_transaction_id) & 0x0f;
73     return delta < 15;
74 }
75 
76 static uint16_t avrcp_get_max_payload_size_for_packet_type(avrcp_packet_type_t packet_type){
77     switch (packet_type){
78         case AVRCP_SINGLE_PACKET:
79             return AVRCP_CMD_BUFFER_SIZE - 3;
80         case AVRCP_START_PACKET:
81             return AVRCP_CMD_BUFFER_SIZE - 4;
82         case AVRCP_CONTINUE_PACKET:
83         case AVRCP_END_PACKET:
84             return AVRCP_CMD_BUFFER_SIZE - 1;
85         default:
86             btstack_assert(false);
87             return 0;
88     }
89 }
90 
91 static int avrcp_controller_supports_browsing(uint16_t controller_supported_features){
92     return controller_supported_features & AVRCP_FEATURE_MASK_BROWSING;
93 }
94 
95 static void avrcp_controller_emit_supported_events(avrcp_connection_t * connection){
96     uint8_t ctype = (uint8_t) AVRCP_CTYPE_RESPONSE_CHANGED_STABLE;
97     uint8_t event_id;
98 
99     for (event_id = (uint8_t) AVRCP_NOTIFICATION_EVENT_PLAYBACK_STATUS_CHANGED; event_id < (uint8_t) AVRCP_NOTIFICATION_EVENT_MAX_VALUE; event_id++){
100         if ( (connection->remote_supported_notifications & (1<<event_id)) == 0){
101             continue;
102         }
103         uint8_t event[8];
104         uint8_t pos = 0;
105         event[pos++] = HCI_EVENT_AVRCP_META;
106         event[pos++] = sizeof(event) - 2;
107         event[pos++] = AVRCP_SUBEVENT_GET_CAPABILITY_EVENT_ID;
108         little_endian_store_16(event, pos, connection->avrcp_cid);
109         pos += 2;
110         event[pos++] = ctype;
111         event[pos++] = 0;
112         event[pos++] = event_id;
113         UNUSED(pos);
114         (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
115     }
116 
117     uint8_t event[7];
118     uint8_t pos = 0;
119     event[pos++] = HCI_EVENT_AVRCP_META;
120     event[pos++] = sizeof(event) - 2;
121     event[pos++] = AVRCP_SUBEVENT_GET_CAPABILITY_EVENT_ID_DONE;
122     little_endian_store_16(event, pos, connection->avrcp_cid);
123     pos += 2;
124     event[pos++] = ctype;
125     event[pos++] = 0;
126     UNUSED(pos);
127     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
128 }
129 
130 static void avrcp_controller_emit_notification_for_event_id(uint16_t avrcp_cid, avrcp_notification_event_id_t event_id,
131                                                             avrcp_command_type_t ctype, const uint8_t *payload,
132                                                             uint16_t size) {
133     switch (event_id){
134         case AVRCP_NOTIFICATION_EVENT_PLAYBACK_POS_CHANGED:{
135             if (size < 4) break;
136             uint32_t song_position = big_endian_read_32(payload, 0);
137             uint16_t offset = 0;
138             uint8_t event[10];
139             event[offset++] = HCI_EVENT_AVRCP_META;
140             event[offset++] = sizeof(event) - 2;
141             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_PLAYBACK_POS_CHANGED;
142             little_endian_store_16(event, offset, avrcp_cid);
143             offset += 2;
144             event[offset++] = ctype;
145             little_endian_store_32(event, offset, song_position);
146             offset += 4;
147             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
148             break;
149         }
150         case AVRCP_NOTIFICATION_EVENT_PLAYBACK_STATUS_CHANGED:{
151             if (size < 1) break;
152             uint16_t offset = 0;
153             uint8_t event[7];
154             event[offset++] = HCI_EVENT_AVRCP_META;
155             event[offset++] = sizeof(event) - 2;
156             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_PLAYBACK_STATUS_CHANGED;
157             little_endian_store_16(event, offset, avrcp_cid);
158             offset += 2;
159             event[offset++] = ctype;
160             event[offset++] = payload[0];
161             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
162             break;
163         }
164         case AVRCP_NOTIFICATION_EVENT_TRACK_CHANGED:{
165             uint16_t offset = 0;
166             uint8_t event[6];
167             event[offset++] = HCI_EVENT_AVRCP_META;
168             event[offset++] = sizeof(event) - 2;
169             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_TRACK_CHANGED;
170             little_endian_store_16(event, offset, avrcp_cid);
171             offset += 2;
172             event[offset++] = ctype;
173             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
174             break;
175         }
176         case AVRCP_NOTIFICATION_EVENT_NOW_PLAYING_CONTENT_CHANGED:{
177             uint16_t offset = 0;
178             uint8_t event[6];
179             event[offset++] = HCI_EVENT_AVRCP_META;
180             event[offset++] = sizeof(event) - 2;
181             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_NOW_PLAYING_CONTENT_CHANGED;
182             little_endian_store_16(event, offset, avrcp_cid);
183             offset += 2;
184             event[offset++] = ctype;
185             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
186             break;
187         }
188         case AVRCP_NOTIFICATION_EVENT_AVAILABLE_PLAYERS_CHANGED:{
189             uint16_t offset = 0;
190             uint8_t event[6];
191             event[offset++] = HCI_EVENT_AVRCP_META;
192             event[offset++] = sizeof(event) - 2;
193             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_AVAILABLE_PLAYERS_CHANGED;
194             little_endian_store_16(event, offset, avrcp_cid);
195             offset += 2;
196             event[offset++] = ctype;
197             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
198             break;
199         }
200         case AVRCP_NOTIFICATION_EVENT_VOLUME_CHANGED:{
201             if (size < 1) break;
202             uint16_t offset = 0;
203             uint8_t event[7];
204             event[offset++] = HCI_EVENT_AVRCP_META;
205             event[offset++] = sizeof(event) - 2;
206             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_VOLUME_CHANGED;
207             little_endian_store_16(event, offset, avrcp_cid);
208             offset += 2;
209             event[offset++] = ctype;
210             event[offset++] = payload[0] & 0x7F;
211             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
212             break;
213         }
214         case AVRCP_NOTIFICATION_EVENT_UIDS_CHANGED:{
215             if (size < 2) break;
216             uint8_t event[8];
217             uint16_t offset = 0;
218             uint16_t uuid = big_endian_read_16(payload, 0);
219             event[offset++] = HCI_EVENT_AVRCP_META;
220             event[offset++] = sizeof(event) - 2;
221             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_UIDS_CHANGED;
222             little_endian_store_16(event, offset, avrcp_cid);
223             offset += 2;
224             event[offset++] = ctype;
225             little_endian_store_16(event, offset, uuid);
226             offset += 2;
227             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
228             break;
229         }
230 
231         case AVRCP_NOTIFICATION_EVENT_TRACK_REACHED_END:{
232             uint16_t offset = 0;
233             uint8_t event[6];
234             event[offset++] = HCI_EVENT_AVRCP_META;
235             event[offset++] = sizeof(event) - 2;
236             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_TRACK_REACHED_END;
237             little_endian_store_16(event, offset, avrcp_cid);
238             offset += 2;
239             event[offset++] = ctype;
240             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
241             break;
242         }
243         case AVRCP_NOTIFICATION_EVENT_TRACK_REACHED_START:{
244             uint16_t offset = 0;
245             uint8_t event[6];
246             event[offset++] = HCI_EVENT_AVRCP_META;
247             event[offset++] = sizeof(event) - 2;
248             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_TRACK_REACHED_START;
249             little_endian_store_16(event, offset, avrcp_cid);
250             offset += 2;
251             event[offset++] = ctype;
252             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
253             break;
254         }
255         case AVRCP_NOTIFICATION_EVENT_BATT_STATUS_CHANGED:{
256             if (size < 1) break;
257             uint16_t offset = 0;
258             uint8_t event[7];
259             event[offset++] = HCI_EVENT_AVRCP_META;
260             event[offset++] = sizeof(event) - 2;
261             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_BATT_STATUS_CHANGED;
262             little_endian_store_16(event, offset, avrcp_cid);
263             offset += 2;
264             event[offset++] = ctype;
265             event[offset++] = payload[0];
266             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
267             break;
268         }
269 
270         case AVRCP_NOTIFICATION_EVENT_SYSTEM_STATUS_CHANGED:{
271             if (size < 1) break;
272             uint16_t offset = 0;
273             uint8_t event[7];
274             event[offset++] = HCI_EVENT_AVRCP_META;
275             event[offset++] = sizeof(event) - 2;
276             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_SYSTEM_STATUS_CHANGED;
277             little_endian_store_16(event, offset, avrcp_cid);
278             offset += 2;
279             event[offset++] = ctype;
280             event[offset++] = payload[0];
281             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
282             break;
283         }
284 
285         case AVRCP_NOTIFICATION_EVENT_PLAYER_APPLICATION_SETTING_CHANGED:
286         default:
287             log_info("avrcp: not implemented");
288             break;
289     }
290 }
291 
292 static void avrcp_controller_emit_repeat_and_shuffle_mode(btstack_packet_handler_t callback, uint16_t avrcp_cid, uint8_t ctype, avrcp_repeat_mode_t repeat_mode, avrcp_shuffle_mode_t shuffle_mode){
293     btstack_assert(callback != NULL);
294 
295     uint8_t event[8];
296     int pos = 0;
297     event[pos++] = HCI_EVENT_AVRCP_META;
298     event[pos++] = sizeof(event) - 2;
299     event[pos++] = AVRCP_SUBEVENT_SHUFFLE_AND_REPEAT_MODE;
300     little_endian_store_16(event, pos, avrcp_cid);
301     pos += 2;
302     event[pos++] = ctype;
303     event[pos++] = repeat_mode;
304     event[pos++] = shuffle_mode;
305     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
306 }
307 
308 static void avrcp_controller_emit_now_playing_info_event_done(btstack_packet_handler_t callback, uint16_t avrcp_cid, uint8_t ctype, uint8_t status){
309     uint8_t event[7];
310     int pos = 0;
311     event[pos++] = HCI_EVENT_AVRCP_META;
312     event[pos++] = sizeof(event) - 2;
313     event[pos++] = AVRCP_SUBEVENT_NOW_PLAYING_INFO_DONE;
314     little_endian_store_16(event, pos, avrcp_cid);
315     pos += 2;
316     event[pos++] = ctype;
317     event[pos++] = status;
318     (*callback)(HCI_EVENT_PACKET, 0, event, pos);
319 }
320 
321 static void avrcp_controller_emit_now_playing_info_event(btstack_packet_handler_t callback, uint16_t avrcp_cid, uint8_t ctype, avrcp_media_attribute_id_t attr_id, uint8_t * value, uint16_t value_len){
322     uint8_t event[HCI_EVENT_BUFFER_SIZE];
323     int pos = 0;
324     event[pos++] = HCI_EVENT_AVRCP_META;
325     // reserve one byte for subevent type and data len
326     int data_len_pos = pos;
327     pos++;
328     int subevent_type_pos = pos;
329     pos++;
330     little_endian_store_16(event, pos, avrcp_cid);
331     pos += 2;
332     event[pos++] = ctype;
333 
334     switch (attr_id){
335         case AVRCP_MEDIA_ATTR_TITLE:
336             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TITLE_INFO;
337             event[pos++] = value_len;
338             (void)memcpy(event + pos, value, value_len);
339             break;
340         case AVRCP_MEDIA_ATTR_ARTIST:
341             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_ARTIST_INFO;
342             event[pos++] = value_len;
343             (void)memcpy(event + pos, value, value_len);
344             break;
345         case AVRCP_MEDIA_ATTR_ALBUM:
346             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_ALBUM_INFO;
347             event[pos++] = value_len;
348             (void)memcpy(event + pos, value, value_len);
349             break;
350         case AVRCP_MEDIA_ATTR_GENRE:
351             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_GENRE_INFO;
352             event[pos++] = value_len;
353             (void)memcpy(event + pos, value, value_len);
354             break;
355         case AVRCP_MEDIA_ATTR_SONG_LENGTH_MS:
356             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_SONG_LENGTH_MS_INFO;
357             if (value){
358                 little_endian_store_32(event, pos, btstack_atoi((char *)value));
359             } else {
360                 little_endian_store_32(event, pos, 0);
361             }
362             pos += 4;
363             break;
364         case AVRCP_MEDIA_ATTR_TRACK:
365             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TRACK_INFO;
366             if (value){
367                 event[pos++] = btstack_atoi((char *)value);
368             } else {
369                 event[pos++] = 0;
370             }
371             break;
372         case AVRCP_MEDIA_ATTR_TOTAL_NUM_ITEMS:
373             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TOTAL_TRACKS_INFO;
374             if (value){
375                 event[pos++] = btstack_atoi((char *)value);
376             } else {
377                 event[pos++] = 0;
378             }
379             break;
380         default:
381             break;
382     }
383     event[data_len_pos] = pos - 2;
384     (*callback)(HCI_EVENT_PACKET, 0, event, pos);
385 }
386 
387 static void avrcp_controller_emit_operation_status(btstack_packet_handler_t callback, uint8_t subevent, uint16_t avrcp_cid, uint8_t ctype, uint8_t operation_id){
388     btstack_assert(callback != NULL);
389 
390     uint8_t event[7];
391     int pos = 0;
392     event[pos++] = HCI_EVENT_AVRCP_META;
393     event[pos++] = sizeof(event) - 2;
394     event[pos++] = subevent;
395     little_endian_store_16(event, pos, avrcp_cid);
396     pos += 2;
397     event[pos++] = ctype;
398     event[pos++] = operation_id;
399     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
400 }
401 
402 static void avrcp_parser_reset(avrcp_connection_t * connection){
403     connection->list_offset = 0;
404     connection->num_attributes = 0;
405     connection->num_parsed_attributes = 0;
406     connection->parser_attribute_header_pos = 0;
407     connection->num_received_fragments = 0;
408     connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_HEADER;
409 }
410 
411 static void avrcp_parser_process_byte(uint8_t byte, avrcp_connection_t * connection, avrcp_command_type_t ctype){
412     uint16_t attribute_total_value_len;
413     uint32_t attribute_id;
414     switch(connection->parser_state){
415         case AVRCP_PARSER_GET_ATTRIBUTE_HEADER:
416             connection->parser_attribute_header[connection->parser_attribute_header_pos++] = byte;
417             connection->list_offset++;
418 
419             if (connection->parser_attribute_header_pos < AVRCP_ATTRIBUTE_HEADER_LEN) return;
420 
421             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
422             connection->attribute_value_len = btstack_min(attribute_total_value_len, AVRCP_MAX_ATTRIBUTTE_SIZE);
423             if (connection->attribute_value_len > 0){
424                 // get ready for attribute value
425                 connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_VALUE;
426                 return;
427             }
428 
429             // emit empty attribute
430             attribute_id = big_endian_read_32(connection->parser_attribute_header, 0);
431             avrcp_controller_emit_now_playing_info_event(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, (avrcp_media_attribute_id_t) attribute_id, connection->attribute_value, connection->attribute_value_len);
432 
433             // done, see below
434             break;
435 
436         case AVRCP_PARSER_GET_ATTRIBUTE_VALUE:
437             connection->attribute_value[connection->attribute_value_offset++] = byte;
438             connection->list_offset++;
439 
440             if (connection->attribute_value_offset < connection->attribute_value_len) return;
441 
442             // emit (potentially partial) attribute
443             attribute_id = big_endian_read_32(connection->parser_attribute_header, 0);
444             avrcp_controller_emit_now_playing_info_event(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, (avrcp_media_attribute_id_t) attribute_id, connection->attribute_value, connection->attribute_value_len);
445 
446             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
447             if (connection->attribute_value_offset < attribute_total_value_len){
448                 // ignore rest of attribute
449                 connection->parser_state = AVRCP_PARSER_IGNORE_REST_OF_ATTRIBUTE_VALUE;
450                 return;
451             }
452 
453             // done, see below
454             break;
455 
456         case AVRCP_PARSER_IGNORE_REST_OF_ATTRIBUTE_VALUE:
457             connection->attribute_value_offset++;
458             connection->list_offset++;
459 
460             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
461             if (connection->attribute_value_offset < attribute_total_value_len) return;
462 
463             // done, see below
464             break;
465 
466         default:
467             return;
468     }
469 
470     // attribute fully read, check if more to come
471     if (connection->list_offset < connection->list_size){
472         // more to come, reset parser
473         connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_HEADER;
474         connection->parser_attribute_header_pos = 0;
475         connection->attribute_value_offset = 0;
476     } else {
477         // fully done
478         avrcp_parser_reset(connection);
479         avrcp_controller_emit_now_playing_info_event_done(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, 0);
480     }
481 }
482 
483 static void avrcp_controller_parse_and_emit_element_attrs(uint8_t * packet, uint16_t num_bytes_to_read, avrcp_connection_t * connection, avrcp_command_type_t ctype){
484     int i;
485     for (i=0;i<num_bytes_to_read;i++){
486         avrcp_parser_process_byte(packet[i], connection, ctype);
487     }
488 }
489 
490 
491 static int avrcp_send_cmd(avrcp_connection_t * connection, avrcp_packet_type_t packet_type){
492     uint8_t  command[AVRCP_CMD_BUFFER_SIZE];
493     uint16_t pos = 0;
494 
495     // non-fragmented: transport header (1) + PID (2)
496     // fragmented:     transport header (1) + num packets (1) + PID (2)
497 
498     // transport header : transaction label | Packet_type | C/R | IPID (1 == invalid profile identifier)
499     command[pos++] = (connection->transaction_id << 4) | (packet_type << 2) | (AVRCP_COMMAND_FRAME << 1) | 0;
500 
501     if (packet_type == AVRCP_START_PACKET){
502         // num packets: (3 bytes overhead (PID, num packets) + command) / (MTU - transport header).
503         // to get number of packets using integer division, we subtract 1 from the data e.g. len = 5, packet size 5 => need 1 packet
504         command[pos++] = ((connection->cmd_operands_fragmented_len + 3 - 1) / (AVRCP_CMD_BUFFER_SIZE - 1)) + 1;
505     }
506 
507     if ((packet_type == AVRCP_SINGLE_PACKET) || (packet_type == AVRCP_START_PACKET)){
508         // Profile IDentifier (PID)
509         command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL >> 8;
510         command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL & 0x00FF;
511 
512         // command_type
513         command[pos++] = connection->command_type;
514         // subunit_type | subunit ID
515         command[pos++] = (connection->subunit_type << 3) | connection->subunit_id;
516         // opcode
517         command[pos++] = (uint8_t)connection->command_opcode;
518     }
519 
520     if (packet_type == AVRCP_SINGLE_PACKET){
521         // operands
522         (void)memcpy(command + pos, connection->cmd_operands,
523                      connection->cmd_operands_length);
524         pos += connection->cmd_operands_length;
525     } else {
526         uint16_t bytes_free = AVRCP_CMD_BUFFER_SIZE - pos;
527         uint16_t bytes_to_store = connection->cmd_operands_fragmented_len-connection->cmd_operands_fragmented_pos;
528         uint16_t bytes_to_copy = btstack_min(bytes_to_store, bytes_free);
529         (void)memcpy(command + pos,
530                      &connection->cmd_operands_fragmented_buffer[connection->cmd_operands_fragmented_pos],
531                      bytes_to_copy);
532         pos += bytes_to_copy;
533         connection->cmd_operands_fragmented_pos += bytes_to_copy;
534     }
535 
536     return l2cap_send(connection->l2cap_signaling_cid, command, pos);
537 }
538 
539 static int avrcp_send_register_notification(avrcp_connection_t * connection, uint8_t event_id){
540     uint8_t command[18];
541     uint16_t pos = 0;
542     // transport header : transaction label | Packet_type | C/R | IPID (1 == invalid profile identifier)
543     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
544     command[pos++] = (connection->transaction_id << 4) | (AVRCP_SINGLE_PACKET << 2) | (AVRCP_COMMAND_FRAME << 1) | 0;
545 
546     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL >> 8;
547     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL & 0x00FF;
548     command[pos++] = AVRCP_CTYPE_NOTIFY;
549     command[pos++] = (AVRCP_SUBUNIT_TYPE_PANEL << 3) | AVRCP_SUBUNIT_ID;
550     command[pos++] = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
551 
552     big_endian_store_24(command, pos, BT_SIG_COMPANY_ID);
553     pos += 3;
554     command[pos++] = AVRCP_PDU_ID_REGISTER_NOTIFICATION;
555     command[pos++] = 0;                       // reserved(upper 6) | packet_type -> 0
556     big_endian_store_16(command, pos, 5);     // parameter length
557     pos += 2;
558     command[pos++] = event_id;
559     big_endian_store_32(command, pos, 1);     // send notification on playback position every second, for other notifications it is ignored
560     pos += 4;
561     return l2cap_send(connection->l2cap_signaling_cid, command, pos);
562 }
563 
564 static void avrcp_press_and_hold_timeout_handler(btstack_timer_source_t * timer){
565     UNUSED(timer);
566     avrcp_connection_t * connection = (avrcp_connection_t*) btstack_run_loop_get_timer_context(timer);
567     btstack_run_loop_set_timer(&connection->press_and_hold_cmd_timer, 2000); // 2 seconds timeout
568     btstack_run_loop_add_timer(&connection->press_and_hold_cmd_timer);
569     connection->state = AVCTP_W2_SEND_PRESS_COMMAND;
570     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
571 }
572 
573 static void avrcp_press_and_hold_timer_start(avrcp_connection_t * connection){
574     btstack_run_loop_remove_timer(&connection->press_and_hold_cmd_timer);
575     btstack_run_loop_set_timer_handler(&connection->press_and_hold_cmd_timer, avrcp_press_and_hold_timeout_handler);
576     btstack_run_loop_set_timer_context(&connection->press_and_hold_cmd_timer, connection);
577     btstack_run_loop_set_timer(&connection->press_and_hold_cmd_timer, 2000); // 2 seconds timeout
578     btstack_run_loop_add_timer(&connection->press_and_hold_cmd_timer);
579 }
580 
581 static void avrcp_press_and_hold_timer_stop(avrcp_connection_t * connection){
582     connection->press_and_hold_cmd_active = false;
583     btstack_run_loop_remove_timer(&connection->press_and_hold_cmd_timer);
584 }
585 
586 
587 static uint8_t avrcp_controller_request_pass_through_release_control_cmd(avrcp_connection_t * connection){
588     connection->state = AVCTP_W2_SEND_RELEASE_COMMAND;
589     if (connection->press_and_hold_cmd_active){
590         avrcp_press_and_hold_timer_stop(connection);
591     }
592     connection->cmd_operands[0] = 0x80 | connection->cmd_operands[0];
593     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
594     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
595     return ERROR_CODE_SUCCESS;
596 }
597 
598 static uint8_t avrcp_controller_request_pass_through_press_control_cmd(uint16_t avrcp_cid, avrcp_operation_id_t opid, uint16_t playback_speed, bool continuous_cmd){
599     log_info("Send command %d", opid);
600     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
601     if (!connection){
602         log_error("Could not find a connection. avrcp cid 0x%02x", avrcp_cid);
603         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
604     }
605 
606     if (connection->state != AVCTP_CONNECTION_OPENED){
607         log_error("Connection in wrong state %d, expected %d. avrcp cid 0x%02x", connection->state, AVCTP_CONNECTION_OPENED, avrcp_cid);
608         return ERROR_CODE_COMMAND_DISALLOWED;
609     }
610     connection->state = AVCTP_W2_SEND_PRESS_COMMAND;
611     connection->command_opcode =  AVRCP_CMD_OPCODE_PASS_THROUGH;
612     connection->command_type = AVRCP_CTYPE_CONTROL;
613     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
614     connection->subunit_id =   AVRCP_SUBUNIT_ID;
615     connection->cmd_operands_length = 0;
616 
617     connection->press_and_hold_cmd_active = continuous_cmd;
618     connection->cmd_operands_length = 2;
619     connection->cmd_operands[0] = opid;
620     if (playback_speed > 0){
621         connection->cmd_operands[2] = playback_speed;
622         connection->cmd_operands_length++;
623     }
624     connection->cmd_operands[1] = connection->cmd_operands_length - 2;
625 
626     if (connection->press_and_hold_cmd_active){
627         avrcp_press_and_hold_timer_start(connection);
628     }
629 
630     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
631     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
632     return ERROR_CODE_SUCCESS;
633 }
634 
635 static uint8_t request_single_pass_through_press_control_cmd(uint16_t avrcp_cid, avrcp_operation_id_t opid, uint16_t playback_speed){
636     return avrcp_controller_request_pass_through_press_control_cmd(avrcp_cid, opid, playback_speed, false);
637 }
638 
639 static uint8_t request_continuous_pass_through_press_control_cmd(uint16_t avrcp_cid, avrcp_operation_id_t opid, uint16_t playback_speed){
640     return avrcp_controller_request_pass_through_press_control_cmd(avrcp_cid, opid, playback_speed, true);
641 }
642 
643 static void avrcp_controller_get_capabilities_for_connection(avrcp_connection_t * connection, uint8_t capability_id){
644     connection->state = AVCTP_W2_SEND_COMMAND;
645     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
646     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
647     connection->command_type = AVRCP_CTYPE_STATUS;
648     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
649     connection->subunit_id = AVRCP_SUBUNIT_ID;
650     big_endian_store_24(connection->cmd_operands, 0, BT_SIG_COMPANY_ID);
651     connection->cmd_operands[3] = AVRCP_PDU_ID_GET_CAPABILITIES; // PDU ID
652     connection->cmd_operands[4] = 0;
653     big_endian_store_16(connection->cmd_operands, 5, 1); // parameter length
654     connection->cmd_operands[7] = capability_id;                  // capability ID
655     connection->cmd_operands_length = 8;
656     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
657 }
658 
659 static uint8_t avrcp_controller_register_notification(avrcp_connection_t * connection, avrcp_notification_event_id_t event_id){
660     if (connection->remote_supported_notifications_queried && (connection->remote_supported_notifications & (1 << event_id)) == 0){
661         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
662     }
663     if ( (connection->notifications_to_deregister & (1 << event_id)) != 0){
664         return ERROR_CODE_COMMAND_DISALLOWED;
665     }
666     if ( (connection->notifications_enabled & (1 << event_id)) != 0){
667         return ERROR_CODE_SUCCESS;
668     }
669     if ( (connection->notifications_to_register & (1 << event_id)) != 0){
670         return ERROR_CODE_SUCCESS;
671     }
672 
673     connection->notifications_to_register |= (1 << event_id);
674 
675     if (!connection->remote_supported_notifications_queried){
676         connection->remote_supported_notifications_suppress_emit_result = true;
677         avrcp_controller_get_capabilities_for_connection(connection, AVRCP_CAPABILITY_ID_EVENT);
678         return ERROR_CODE_SUCCESS;
679     }
680     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
681     return ERROR_CODE_SUCCESS;
682 }
683 
684 static uint8_t avrcp_controller_request_abort_continuation(avrcp_connection_t * connection){
685     connection->state = AVCTP_W2_SEND_COMMAND;
686     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
687     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
688     connection->command_type = AVRCP_CTYPE_CONTROL;
689     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
690     connection->subunit_id = AVRCP_SUBUNIT_ID;
691     int pos = 0;
692     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
693     pos += 3;
694     connection->cmd_operands[pos++] = AVRCP_PDU_ID_REQUEST_ABORT_CONTINUING_RESPONSE; // PDU ID
695     connection->cmd_operands[pos++] = 0;
696     // Parameter Length
697     connection->cmd_operands_length = 8;
698     big_endian_store_16(connection->cmd_operands, pos, 1);
699     pos += 2;
700     connection->cmd_operands[pos++] = AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES;
701     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
702     return ERROR_CODE_SUCCESS;
703 }
704 
705 
706 static uint8_t avrcp_controller_request_continue_response(avrcp_connection_t * connection){
707     connection->state = AVCTP_W2_SEND_COMMAND;
708     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
709     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
710     connection->command_type = AVRCP_CTYPE_CONTROL;
711     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
712     connection->subunit_id = AVRCP_SUBUNIT_ID;
713     int pos = 0;
714     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
715     pos += 3;
716     connection->cmd_operands[pos++] = AVRCP_PDU_ID_REQUEST_CONTINUING_RESPONSE; // PDU ID
717     connection->cmd_operands[pos++] = 0;
718     // Parameter Length
719     connection->cmd_operands_length = 8;
720     big_endian_store_16(connection->cmd_operands, pos, 1);
721     pos += 2;
722     connection->cmd_operands[pos++] = AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES;
723     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
724     return ERROR_CODE_SUCCESS;
725 }
726 
727 static void
728 avrcp_controller_handle_notification(avrcp_connection_t *connection, avrcp_command_type_t ctype, uint8_t *payload, uint16_t size) {
729     if (size < 1) return;
730     uint16_t pos = 0;
731     avrcp_notification_event_id_t event_id = (avrcp_notification_event_id_t) payload[pos++];
732     uint16_t event_mask = (1 << event_id);
733     uint16_t reset_event_mask = ~event_mask;
734 
735     switch (ctype){
736         case AVRCP_CTYPE_RESPONSE_INTERIM:
737             // register as enabled
738             connection->notifications_enabled |= event_mask;
739             if ( (connection->initial_status_reported & event_mask) > 0 ){
740                 return;
741             }
742             connection->initial_status_reported |= event_mask;
743             break;
744         case AVRCP_CTYPE_RESPONSE_CHANGED_STABLE:
745             // received change, event is considered deregistered
746             // we are re-enabling it automatically, if it is not
747             // explicitly disabled
748             connection->notifications_enabled &= reset_event_mask;
749             if (! (connection->notifications_to_deregister & event_mask)){
750                 avrcp_controller_register_notification(connection, event_id);
751             } else {
752                 connection->notifications_to_deregister &= reset_event_mask;
753             }
754             break;
755         default:
756             connection->notifications_to_register &= reset_event_mask;
757             connection->notifications_enabled &= reset_event_mask;
758             connection->notifications_to_deregister &= reset_event_mask;
759             break;
760     }
761 
762     avrcp_controller_emit_notification_for_event_id(connection->avrcp_cid, event_id, ctype, payload + pos, size - pos);
763 }
764 
765 #ifdef ENABLE_AVCTP_FRAGMENTATION
766 static void avctp_reassemble_message(avrcp_connection_t * connection, avctp_packet_type_t packet_type, uint8_t *packet, uint16_t size){
767     // after header (transaction label and packet type)
768     uint16_t pos;
769     uint16_t bytes_to_store;
770 
771     switch (packet_type){
772         case AVCTP_START_PACKET:
773             if (size < 2) return;
774 
775             // store header
776             pos = 0;
777             connection->avctp_reassembly_buffer[pos] = packet[pos];
778             pos++;
779             connection->avctp_reassembly_size = pos;
780 
781             // NOTE: num packets not needed for reassembly, ignoring it does not pose security risk -> no need to store it
782             pos++;
783 
784             // PID in reassembled packet is at offset 1, it will be read later after the avctp_reassemble_message with AVCTP_END_PACKET is called
785 
786             bytes_to_store = btstack_min(size - pos, sizeof(connection->avctp_reassembly_buffer) - connection->avctp_reassembly_size);
787             memcpy(&connection->avctp_reassembly_buffer[connection->avctp_reassembly_size], &packet[pos], bytes_to_store);
788             connection->avctp_reassembly_size += bytes_to_store;
789             break;
790 
791         case AVCTP_CONTINUE_PACKET:
792         case AVCTP_END_PACKET:
793             if (size < 1) return;
794 
795             // store remaining data, ignore header
796             pos = 1;
797             bytes_to_store = btstack_min(size - pos, sizeof(connection->avctp_reassembly_buffer) - connection->avctp_reassembly_size);
798             memcpy(&connection->avctp_reassembly_buffer[connection->avctp_reassembly_size], &packet[pos], bytes_to_store);
799             connection->avctp_reassembly_size += bytes_to_store;
800             break;
801 
802         default:
803             return;
804     }
805 }
806 #endif
807 
808 static void avrcp_handle_l2cap_data_packet_for_signaling_connection(avrcp_connection_t * connection, uint8_t *packet, uint16_t size){
809     if (size < 6u) return;
810     uint8_t  pdu_id;
811     avrcp_packet_type_t  vendor_dependent_packet_type;
812 
813     uint16_t pos = 0;
814     connection->last_confirmed_transaction_id = packet[pos] >> 4;
815     avrcp_frame_type_t  frame_type =  (avrcp_frame_type_t)((packet[pos] >> 1) & 0x01);
816     avctp_packet_type_t packet_type = (avctp_packet_type_t)((packet[pos] >> 2) & 0x03);
817     pos++;
818 
819     if (frame_type != AVRCP_RESPONSE_FRAME) return;
820 
821     switch (packet_type){
822         case AVCTP_SINGLE_PACKET:
823             break;
824 
825 #ifdef ENABLE_AVCTP_FRAGMENTATION
826         case AVCTP_START_PACKET:
827         case AVCTP_CONTINUE_PACKET:
828             avctp_reassemble_message(connection, packet_type, packet, size);
829             return;
830 
831         case AVCTP_END_PACKET:
832             avctp_reassemble_message(connection, packet_type, packet, size);
833 
834             packet = connection->avctp_reassembly_buffer;
835             size   = connection->avctp_reassembly_size;
836             break;
837 #endif
838 
839         default:
840             return;
841     }
842 
843     pos += 2; // PID
844 
845     avrcp_command_type_t ctype = (avrcp_command_type_t) packet[pos++];
846 
847 #ifdef ENABLE_LOG_INFO
848     uint8_t byte_value = packet[pos];
849     avrcp_subunit_type_t subunit_type = (avrcp_subunit_type_t) (byte_value >> 3);
850     avrcp_subunit_type_t subunit_id   = (avrcp_subunit_type_t) (byte_value & 0x07);
851 #endif
852     pos++;
853 
854     uint8_t opcode = packet[pos++];
855     uint16_t param_length;
856 
857     switch (opcode){
858         case AVRCP_CMD_OPCODE_SUBUNIT_INFO:{
859             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE) return;
860             connection->state = AVCTP_CONNECTION_OPENED;
861 
862 #ifdef ENABLE_LOG_INFO
863             // page, extention code (1)
864             pos++;
865             uint8_t unit_type = packet[pos] >> 3;
866             uint8_t max_subunit_ID = packet[pos] & 0x07;
867             log_info("SUBUNIT INFO response: ctype 0x%02x (0C), subunit_type 0x%02x (1F), subunit_id 0x%02x (07), opcode 0x%02x (30), unit_type 0x%02x, max_subunit_ID %d", ctype, subunit_type, subunit_id, opcode, unit_type, max_subunit_ID);
868 #endif
869             break;
870         }
871         case AVRCP_CMD_OPCODE_UNIT_INFO:{
872             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE) return;
873             connection->state = AVCTP_CONNECTION_OPENED;
874 
875 #ifdef ENABLE_LOG_INFO
876             // byte value 7 (1)
877             pos++;
878             uint8_t unit_type = packet[pos] >> 3;
879             uint8_t unit = packet[pos] & 0x07;
880             pos++;
881             uint32_t company_id = big_endian_read_24(packet, pos);
882             log_info("UNIT INFO response: ctype 0x%02x (0C), subunit_type 0x%02x (1F), subunit_id 0x%02x (07), opcode 0x%02x (30), unit_type 0x%02x, unit %d, company_id 0x%06" PRIx32,
883                 ctype, subunit_type, subunit_id, opcode, unit_type, unit, company_id);
884 #endif
885             break;
886         }
887         case AVRCP_CMD_OPCODE_VENDOR_DEPENDENT:
888 
889             if ((size - pos) < 7) return;
890 
891             // Company ID (3)
892             pos += 3;
893             pdu_id = packet[pos++];
894             vendor_dependent_packet_type = (avrcp_packet_type_t)(packet[pos++] & 0x03);
895             param_length = big_endian_read_16(packet, pos);
896             pos += 2;
897 
898             if ((size - pos) < param_length) return;
899 
900             // handle asynchronous notifications, without changing state
901             if (pdu_id == AVRCP_PDU_ID_REGISTER_NOTIFICATION){
902                 avrcp_controller_handle_notification(connection, ctype, packet + pos, size - pos);
903                 break;
904             }
905 
906             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE){
907                 log_info("AVRCP_CMD_OPCODE_VENDOR_DEPENDENT state %d", connection->state);
908                 return;
909             }
910             connection->state = AVCTP_CONNECTION_OPENED;
911 
912             log_info("VENDOR DEPENDENT response: pdu id 0x%02x, param_length %d, status %s", pdu_id, param_length, avrcp_ctype2str(ctype));
913             switch (pdu_id){
914                 case AVRCP_PDU_ID_GET_CURRENT_PLAYER_APPLICATION_SETTING_VALUE:{
915                     uint8_t num_attributes = packet[pos++];
916                     int i;
917                     avrcp_repeat_mode_t  repeat_mode =  AVRCP_REPEAT_MODE_INVALID;
918                     avrcp_shuffle_mode_t shuffle_mode = AVRCP_SHUFFLE_MODE_INVALID;
919                     for (i = 0; i < num_attributes; i++){
920                         uint8_t attribute_id    = packet[pos++];
921                         uint8_t value = packet[pos++];
922                         switch (attribute_id){
923                             case 0x02:
924                                 repeat_mode = (avrcp_repeat_mode_t) value;
925                                 break;
926                             case 0x03:
927                                 shuffle_mode = (avrcp_shuffle_mode_t) value;
928                                 break;
929                             default:
930                                 break;
931                         }
932                     }
933                     avrcp_controller_emit_repeat_and_shuffle_mode(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, repeat_mode, shuffle_mode);
934                     break;
935                 }
936 
937                 case AVRCP_PDU_ID_SET_PLAYER_APPLICATION_SETTING_VALUE:{
938                     uint16_t offset = 0;
939                     uint8_t event[6];
940                     event[offset++] = HCI_EVENT_AVRCP_META;
941                     event[offset++] = sizeof(event) - 2;
942                     event[offset++] = AVRCP_SUBEVENT_PLAYER_APPLICATION_VALUE_RESPONSE;
943                     little_endian_store_16(event, offset, connection->avrcp_cid);
944                     offset += 2;
945                     event[offset++] = ctype;
946                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
947                     break;
948                 }
949 
950                 case AVRCP_PDU_ID_SET_ABSOLUTE_VOLUME:{
951                     uint16_t offset = 0;
952                     uint8_t event[7];
953                     event[offset++] = HCI_EVENT_AVRCP_META;
954                     event[offset++] = sizeof(event) - 2;
955                     event[offset++] = AVRCP_SUBEVENT_SET_ABSOLUTE_VOLUME_RESPONSE;
956                     little_endian_store_16(event, offset, connection->avrcp_cid);
957                     offset += 2;
958                     event[offset++] = ctype;
959                     event[offset++] = packet[pos++];
960                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
961                     break;
962                 }
963 
964                 case AVRCP_PDU_ID_GET_CAPABILITIES:{
965                     avrcp_capability_id_t capability_id = (avrcp_capability_id_t) packet[pos++];
966                     uint8_t capability_count = 0;
967                     if (param_length > 1){
968                         capability_count = packet[pos++];
969                     }
970                     uint16_t i;
971                     uint16_t offset = 0;
972                     uint8_t event[10];
973 
974                     switch (capability_id){
975 
976                         case AVRCP_CAPABILITY_ID_COMPANY:
977                             for (i = 0; (i < capability_count) && ((size - pos) >= 3); i++){
978                                 uint32_t company_id = big_endian_read_24(packet, pos);
979                                 pos += 3;
980                                 log_info("  0x%06" PRIx32 ", ", company_id);
981 
982                                 offset = 0;
983                                 event[offset++] = HCI_EVENT_AVRCP_META;
984                                 event[offset++] = sizeof(event) - 2;
985                                 event[offset++] = AVRCP_SUBEVENT_GET_CAPABILITY_COMPANY_ID;
986                                 little_endian_store_16(event, offset, connection->avrcp_cid);
987                                 offset += 2;
988                                 event[offset++] = ctype;
989                                 event[offset++] = 0;
990                                 little_endian_store_24(event, offset, company_id);
991                                 offset += 3;
992                                 (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, offset);
993                             }
994 
995                             offset = 0;
996                             event[offset++] = HCI_EVENT_AVRCP_META;
997                             event[offset++] = sizeof(event) - 2;
998                             event[offset++] = AVRCP_SUBEVENT_GET_CAPABILITY_COMPANY_ID_DONE;
999                             little_endian_store_16(event, offset, connection->avrcp_cid);
1000                             offset += 2;
1001                             event[offset++] = ctype;
1002                             event[offset++] = 0;
1003                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, offset);
1004                             break;
1005 
1006                         case AVRCP_CAPABILITY_ID_EVENT:
1007                             for (i = 0; (i < capability_count) && ((size - pos) >= 1); i++){
1008                                 uint8_t event_id = packet[pos++];
1009                                 connection->remote_supported_notifications |= (1 << event_id);
1010                             }
1011                             if (connection->remote_supported_notifications_suppress_emit_result){
1012                                 connection->remote_supported_notifications_suppress_emit_result = false;
1013                                 break;
1014                             }
1015                             avrcp_controller_emit_supported_events(connection);
1016                             break;
1017 
1018                         default:
1019                             // ignore
1020                             break;
1021                     }
1022                     break;
1023                 }
1024 
1025                 case AVRCP_PDU_ID_GET_PLAY_STATUS:{
1026                     uint32_t song_length = big_endian_read_32(packet, pos);
1027                     pos += 4;
1028                     uint32_t song_position = big_endian_read_32(packet, pos);
1029                     pos += 4;
1030                     uint8_t play_status = packet[pos];
1031 
1032                     uint8_t event[15];
1033                     int offset = 0;
1034                     event[offset++] = HCI_EVENT_AVRCP_META;
1035                     event[offset++] = sizeof(event) - 2;
1036                     event[offset++] = AVRCP_SUBEVENT_PLAY_STATUS;
1037                     little_endian_store_16(event, offset, connection->avrcp_cid);
1038                     offset += 2;
1039                     event[offset++] = ctype;
1040                     little_endian_store_32(event, offset, song_length);
1041                     offset += 4;
1042                     little_endian_store_32(event, offset, song_position);
1043                     offset += 4;
1044                     event[offset++] = play_status;
1045                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
1046                     break;
1047                 }
1048 
1049                 case AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES:{
1050                     switch (vendor_dependent_packet_type){
1051                         case AVRCP_START_PACKET:
1052                         case AVRCP_SINGLE_PACKET:
1053                             avrcp_parser_reset(connection);
1054                             connection->list_size = param_length;
1055                             connection->num_attributes = packet[pos++];
1056 
1057                             avrcp_controller_parse_and_emit_element_attrs(packet+pos, size-pos, connection, ctype);
1058                             if (vendor_dependent_packet_type == AVRCP_START_PACKET){
1059                                 avrcp_controller_request_continue_response(connection);
1060                             }
1061                             break;
1062                         case AVRCP_CONTINUE_PACKET:
1063                         case AVRCP_END_PACKET:
1064                             connection->num_received_fragments++;
1065 
1066                             if (connection->num_received_fragments < connection->max_num_fragments){
1067                                 avrcp_controller_parse_and_emit_element_attrs(packet+pos, size-pos, connection, ctype);
1068 
1069                                 if (vendor_dependent_packet_type == AVRCP_CONTINUE_PACKET){
1070                                     avrcp_controller_request_continue_response(connection);
1071                                 }
1072                             } else {
1073                                 avrcp_controller_emit_now_playing_info_event_done(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, 1);
1074                                 avrcp_parser_reset(connection);
1075                                 avrcp_controller_request_abort_continuation(connection);
1076                             }
1077                             break;
1078                         default:
1079                             // TODO check
1080                             btstack_assert(false);
1081                             break;
1082                     }
1083                 }
1084                 default:
1085                     break;
1086             }
1087             break;
1088         case AVRCP_CMD_OPCODE_PASS_THROUGH:{
1089             if ((size - pos) < 1) return;
1090             uint8_t operation_id = packet[pos++];
1091             switch (connection->state){
1092                 case AVCTP_W2_RECEIVE_PRESS_RESPONSE:
1093                     // trigger release for simple command:
1094                     if (!connection->press_and_hold_cmd_active){
1095                         connection->state = AVCTP_W2_SEND_RELEASE_COMMAND;
1096                         break;
1097                     }
1098                     // for press and hold, send release if it just has been requested, otherwise, wait for next repeat
1099                     if (connection->press_and_hold_cmd_release){
1100                         connection->press_and_hold_cmd_release = false;
1101                         connection->state = AVCTP_W2_SEND_RELEASE_COMMAND;
1102                     } else {
1103                         connection->state = AVCTP_W4_STOP;
1104                     }
1105                     break;
1106                 case AVCTP_W2_RECEIVE_RESPONSE:
1107                     connection->state = AVCTP_CONNECTION_OPENED;
1108                     break;
1109                 default:
1110                     break;
1111             }
1112             if (connection->state == AVCTP_W4_STOP){
1113                 avrcp_controller_emit_operation_status(avrcp_controller_context.avrcp_callback, AVRCP_SUBEVENT_OPERATION_START, connection->avrcp_cid, ctype, operation_id);
1114             }
1115             if (connection->state == AVCTP_CONNECTION_OPENED) {
1116                 // RELEASE response
1117                 operation_id = operation_id & 0x7F;
1118                 avrcp_controller_emit_operation_status(avrcp_controller_context.avrcp_callback, AVRCP_SUBEVENT_OPERATION_COMPLETE, connection->avrcp_cid, ctype, operation_id);
1119             }
1120             if (connection->state == AVCTP_W2_SEND_RELEASE_COMMAND){
1121                 // PRESS response
1122                 avrcp_controller_request_pass_through_release_control_cmd(connection);
1123             }
1124             break;
1125         }
1126         default:
1127             break;
1128     }
1129 
1130     // trigger pending notification reqistrations
1131     if ((connection->state == AVCTP_CONNECTION_OPENED) && connection->notifications_to_register){
1132         avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1133     }
1134 }
1135 
1136 static void avrcp_controller_handle_can_send_now(avrcp_connection_t * connection){
1137     switch (connection->state){
1138         case AVCTP_W2_SEND_PRESS_COMMAND:
1139             connection->state = AVCTP_W2_RECEIVE_PRESS_RESPONSE;
1140             avrcp_send_cmd(connection, AVRCP_SINGLE_PACKET);
1141             return;
1142         case AVCTP_W2_SEND_COMMAND:
1143         case AVCTP_W2_SEND_RELEASE_COMMAND:
1144             connection->state = AVCTP_W2_RECEIVE_RESPONSE;
1145             avrcp_send_cmd(connection, AVRCP_SINGLE_PACKET);
1146             return;
1147         case AVCTP_W2_SEND_FRAGMENTED_COMMAND:
1148             if (connection->cmd_operands_fragmented_pos == 0){
1149                  avrcp_send_cmd(connection, AVRCP_START_PACKET);
1150                  avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1151             } else {
1152                 if ((connection->cmd_operands_fragmented_len - connection->cmd_operands_fragmented_pos) > avrcp_get_max_payload_size_for_packet_type(AVRCP_CONTINUE_PACKET)){
1153                      avrcp_send_cmd(connection, AVRCP_CONTINUE_PACKET);
1154                      avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1155                  } else {
1156                     connection->state = AVCTP_W2_RECEIVE_RESPONSE;
1157                     avrcp_send_cmd(connection, AVRCP_END_PACKET);
1158                  }
1159             }
1160             return;
1161         default:
1162             break;
1163     }
1164     // send register notification if queued
1165     if (connection->notifications_to_register != 0){
1166         uint8_t event_id;
1167         for (event_id = 1; event_id <= AVRCP_NOTIFICATION_EVENT_VOLUME_CHANGED; event_id++){
1168             if (connection->notifications_to_register & (1<<event_id)){
1169                 connection->notifications_to_register &= ~ (1 << event_id);
1170                 avrcp_send_register_notification(connection, event_id);
1171                 return;
1172             }
1173         }
1174     }
1175 }
1176 
1177 static void avrcp_controller_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
1178     avrcp_connection_t * connection;
1179 
1180     switch (packet_type) {
1181         case L2CAP_DATA_PACKET:
1182             connection = avrcp_get_connection_for_l2cap_signaling_cid_for_role(AVRCP_CONTROLLER, channel);
1183             avrcp_handle_l2cap_data_packet_for_signaling_connection(connection, packet, size);
1184             break;
1185 
1186         case HCI_EVENT_PACKET:
1187             switch (hci_event_packet_get_type(packet)){
1188                 case L2CAP_EVENT_CAN_SEND_NOW:
1189                     connection = avrcp_get_connection_for_l2cap_signaling_cid_for_role(AVRCP_CONTROLLER, channel);
1190                     avrcp_controller_handle_can_send_now(connection);
1191                     break;
1192             default:
1193                 break;
1194         }
1195         default:
1196             break;
1197     }
1198 }
1199 
1200 void avrcp_controller_create_sdp_record(uint8_t * service, uint32_t service_record_handle, uint16_t supported_features, const char * service_name, const char * service_provider_name){
1201     avrcp_create_sdp_record(1, service, service_record_handle, avrcp_controller_supports_browsing(supported_features), supported_features, service_name, service_provider_name);
1202 }
1203 
1204 void avrcp_controller_init(void){
1205     avrcp_controller_context.role = AVRCP_CONTROLLER;
1206     avrcp_controller_context.packet_handler = avrcp_controller_packet_handler;
1207     avrcp_register_controller_packet_handler(&avrcp_controller_packet_handler);
1208 }
1209 
1210 void avrcp_controller_deinit(void){
1211     memset(&avrcp_controller_context, 0, sizeof(avrcp_context_t));
1212 }
1213 
1214 void avrcp_controller_register_packet_handler(btstack_packet_handler_t callback){
1215     btstack_assert(callback != NULL);
1216     avrcp_controller_context.avrcp_callback = callback;
1217 }
1218 
1219 
1220 uint8_t avrcp_controller_play(uint16_t avrcp_cid){
1221     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PLAY, 0);
1222 }
1223 
1224 uint8_t avrcp_controller_stop(uint16_t avrcp_cid){
1225     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_STOP, 0);
1226 }
1227 
1228 uint8_t avrcp_controller_pause(uint16_t avrcp_cid){
1229     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PAUSE, 0);
1230 }
1231 
1232 uint8_t avrcp_controller_forward(uint16_t avrcp_cid){
1233     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FORWARD, 0);
1234 }
1235 
1236 uint8_t avrcp_controller_backward(uint16_t avrcp_cid){
1237     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_BACKWARD, 0);
1238 }
1239 
1240 uint8_t avrcp_controller_volume_up(uint16_t avrcp_cid){
1241     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_UP, 0);
1242 }
1243 
1244 uint8_t avrcp_controller_volume_down(uint16_t avrcp_cid){
1245     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_DOWN, 0);
1246 }
1247 
1248 uint8_t avrcp_controller_mute(uint16_t avrcp_cid){
1249     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_MUTE, 0);
1250 }
1251 
1252 uint8_t avrcp_controller_skip(uint16_t avrcp_cid){
1253     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_SKIP, 0);
1254 }
1255 
1256 uint8_t avrcp_controller_fast_forward(uint16_t avrcp_cid){
1257     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FAST_FORWARD, 0);
1258 }
1259 
1260 uint8_t avrcp_controller_rewind(uint16_t avrcp_cid){
1261     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_REWIND, 0);
1262 }
1263 
1264 /* start continuous cmds */
1265 
1266 uint8_t avrcp_controller_start_press_and_hold_cmd(uint16_t avrcp_cid, avrcp_operation_id_t operation_id){
1267     return request_continuous_pass_through_press_control_cmd(avrcp_cid, operation_id, 0);
1268 }
1269 
1270 uint8_t avrcp_controller_press_and_hold_play(uint16_t avrcp_cid){
1271     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PLAY, 0);
1272 }
1273 uint8_t avrcp_controller_press_and_hold_stop(uint16_t avrcp_cid){
1274     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_STOP, 0);
1275 }
1276 uint8_t avrcp_controller_press_and_hold_pause(uint16_t avrcp_cid){
1277     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PAUSE, 0);
1278 }
1279 uint8_t avrcp_controller_press_and_hold_forward(uint16_t avrcp_cid){
1280     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FORWARD, 0);
1281 }
1282 uint8_t avrcp_controller_press_and_hold_backward(uint16_t avrcp_cid){
1283     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_BACKWARD, 0);
1284 }
1285 uint8_t avrcp_controller_press_and_hold_fast_forward(uint16_t avrcp_cid){
1286     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FAST_FORWARD, 0);
1287 }
1288 uint8_t avrcp_controller_press_and_hold_rewind(uint16_t avrcp_cid){
1289     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_REWIND, 0);
1290 }
1291 uint8_t avrcp_controller_press_and_hold_volume_up(uint16_t avrcp_cid){
1292     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_UP, 0);
1293 }
1294 uint8_t avrcp_controller_press_and_hold_volume_down(uint16_t avrcp_cid){
1295     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_DOWN, 0);
1296 }
1297 uint8_t avrcp_controller_press_and_hold_mute(uint16_t avrcp_cid){
1298     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_MUTE, 0);
1299 }
1300 
1301 /* stop continuous cmds */
1302 uint8_t avrcp_controller_release_press_and_hold_cmd(uint16_t avrcp_cid){
1303     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1304     if (!connection){
1305         log_error("avrcp_stop_play: could not find a connection.");
1306         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1307     }
1308 
1309     switch (connection->state){
1310         // respond when we receive response for (repeated) press command
1311         case AVCTP_W2_RECEIVE_PRESS_RESPONSE:
1312             connection->press_and_hold_cmd_release = true;
1313             break;
1314 
1315         // release already sent or on the way, nothing to do
1316         case AVCTP_W2_RECEIVE_RESPONSE:
1317         case AVCTP_W2_SEND_RELEASE_COMMAND:
1318             break;
1319 
1320         // about to send next repeated press command or wait for it -> release right away
1321         case AVCTP_W2_SEND_PRESS_COMMAND:
1322         case AVCTP_W4_STOP:
1323             return avrcp_controller_request_pass_through_release_control_cmd(connection);
1324 
1325         // otherwise reject request
1326         default:
1327             return ERROR_CODE_COMMAND_DISALLOWED;
1328     }
1329     return ERROR_CODE_SUCCESS;
1330 }
1331 
1332 uint8_t avrcp_controller_enable_notification(uint16_t avrcp_cid, avrcp_notification_event_id_t event_id){
1333     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1334     if (!connection){
1335         log_error("avrcp_get_play_status: could not find a connection.");
1336         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1337     }
1338     return avrcp_controller_register_notification(connection, event_id);
1339 }
1340 
1341 uint8_t avrcp_controller_disable_notification(uint16_t avrcp_cid, avrcp_notification_event_id_t event_id){
1342     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1343     if (!connection){
1344         log_error("avrcp_get_play_status: could not find a connection.");
1345         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1346     }
1347     connection->notifications_to_deregister |= (1 << event_id);
1348     return ERROR_CODE_SUCCESS;
1349 }
1350 
1351 uint8_t avrcp_controller_unit_info(uint16_t avrcp_cid){
1352     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1353     if (!connection){
1354         log_error("avrcp_unit_info: could not find a connection.");
1355         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1356     }
1357     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1358     connection->state = AVCTP_W2_SEND_COMMAND;
1359 
1360     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
1361     connection->command_opcode = AVRCP_CMD_OPCODE_UNIT_INFO;
1362     connection->command_type = AVRCP_CTYPE_STATUS;
1363     connection->subunit_type = AVRCP_SUBUNIT_TYPE_UNIT; //vendor unique
1364     connection->subunit_id =   AVRCP_SUBUNIT_ID_IGNORE;
1365     memset(connection->cmd_operands, 0xFF, connection->cmd_operands_length);
1366     connection->cmd_operands_length = 5;
1367     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1368     return ERROR_CODE_SUCCESS;
1369 }
1370 
1371 uint8_t avrcp_controller_subunit_info(uint16_t avrcp_cid){
1372     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1373     if (!connection){
1374         log_error("avrcp_unit_info: could not find a connection.");
1375         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1376     }
1377     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1378     connection->state = AVCTP_W2_SEND_COMMAND;
1379 
1380     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
1381     connection->command_opcode = AVRCP_CMD_OPCODE_SUBUNIT_INFO;
1382     connection->command_type = AVRCP_CTYPE_STATUS;
1383     connection->subunit_type = AVRCP_SUBUNIT_TYPE_UNIT; //vendor unique
1384     connection->subunit_id =   AVRCP_SUBUNIT_ID_IGNORE;
1385     memset(connection->cmd_operands, 0xFF, connection->cmd_operands_length);
1386     connection->cmd_operands[0] = 7; // page: 0, extention_code: 7
1387     connection->cmd_operands_length = 5;
1388     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1389     return ERROR_CODE_SUCCESS;
1390 }
1391 
1392 uint8_t avrcp_controller_get_supported_company_ids(uint16_t avrcp_cid){
1393     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1394     if (!connection){
1395         log_error("avrcp_get_capabilities: could not find a connection.");
1396         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1397     }
1398     if (connection->state != AVCTP_CONNECTION_OPENED){
1399         return ERROR_CODE_COMMAND_DISALLOWED;
1400     }
1401     avrcp_controller_get_capabilities_for_connection(connection, AVRCP_CAPABILITY_ID_COMPANY);
1402     return ERROR_CODE_SUCCESS;
1403 }
1404 
1405 uint8_t avrcp_controller_get_supported_events(uint16_t avrcp_cid){
1406     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1407     if (!connection){
1408         log_error("avrcp_get_capabilities: could not find a connection.");
1409         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1410     }
1411     if (connection->state != AVCTP_CONNECTION_OPENED){
1412         return ERROR_CODE_COMMAND_DISALLOWED;
1413     }
1414 
1415     if (!connection->remote_supported_notifications_queried){
1416         connection->remote_supported_notifications_queried = true;
1417         avrcp_controller_get_capabilities_for_connection(connection, AVRCP_CAPABILITY_ID_EVENT);
1418         return ERROR_CODE_SUCCESS;
1419     }
1420 
1421     avrcp_controller_emit_supported_events(connection);
1422     return ERROR_CODE_SUCCESS;
1423 }
1424 
1425 uint8_t avrcp_controller_get_play_status(uint16_t avrcp_cid){
1426     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1427     if (!connection){
1428         log_error("avrcp_get_play_status: could not find a connection.");
1429         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1430     }
1431     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1432     connection->state = AVCTP_W2_SEND_COMMAND;
1433     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
1434     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1435     connection->command_type = AVRCP_CTYPE_STATUS;
1436     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1437     connection->subunit_id = AVRCP_SUBUNIT_ID;
1438     big_endian_store_24(connection->cmd_operands, 0, BT_SIG_COMPANY_ID);
1439     connection->cmd_operands[3] = AVRCP_PDU_ID_GET_PLAY_STATUS;
1440     connection->cmd_operands[4] = 0;                     // reserved(upper 6) | packet_type -> 0
1441     big_endian_store_16(connection->cmd_operands, 5, 0); // parameter length
1442     connection->cmd_operands_length = 7;
1443     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1444     return ERROR_CODE_SUCCESS;
1445 }
1446 
1447 uint8_t avrcp_controller_set_addressed_player(uint16_t avrcp_cid, uint16_t addressed_player_id){
1448     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1449     if (!connection){
1450         log_error("avrcp_get_capabilities: could not find a connection.");
1451         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1452     }
1453     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1454     connection->state = AVCTP_W2_SEND_COMMAND;
1455 
1456     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
1457     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1458     connection->command_type = AVRCP_CTYPE_CONTROL;
1459     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1460     connection->subunit_id = AVRCP_SUBUNIT_ID;
1461     int pos = 0;
1462     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1463     pos += 3;
1464     connection->cmd_operands[pos++] = AVRCP_PDU_ID_SET_ADDRESSED_PLAYER; // PDU ID
1465     connection->cmd_operands[pos++] = 0;
1466 
1467     // Parameter Length
1468     big_endian_store_16(connection->cmd_operands, pos, 2);
1469     pos += 2;
1470 
1471     big_endian_store_16(connection->cmd_operands, pos, addressed_player_id);
1472     pos += 2;
1473 
1474     connection->cmd_operands_length = pos;
1475     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1476     return ERROR_CODE_SUCCESS;
1477 }
1478 
1479 uint8_t avrcp_controller_get_element_attributes(uint16_t avrcp_cid, uint8_t num_attributes, avrcp_media_attribute_id_t * attributes){
1480     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1481     if (!connection){
1482         log_error("avrcp_get_capabilities: could not find a connection.");
1483         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1484     }
1485 
1486     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1487 
1488     if (num_attributes >= AVRCP_MEDIA_ATTR_RESERVED) {
1489         return ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS;
1490     }
1491     connection->state = AVCTP_W2_SEND_COMMAND;
1492 
1493     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
1494     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1495     connection->command_type = AVRCP_CTYPE_STATUS;
1496     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1497     connection->subunit_id = AVRCP_SUBUNIT_ID;
1498     int pos = 0;
1499     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1500     pos += 3;
1501     connection->cmd_operands[pos++] = AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES; // PDU ID
1502     connection->cmd_operands[pos++] = 0;
1503 
1504     // Parameter Length
1505     big_endian_store_16(connection->cmd_operands, pos, 9);
1506     pos += 2;
1507 
1508     // write 8 bytes value
1509     memset(connection->cmd_operands + pos, 0, 8); // identifier: PLAYING
1510     pos += 8;
1511 
1512     connection->cmd_operands[pos++] = num_attributes; // attribute count, if 0 get all attributes
1513 
1514     int i;
1515     for (i = 0; i < num_attributes; i++){
1516         // every attribute is 4 bytes long
1517         big_endian_store_32(connection->cmd_operands, pos, attributes[i]);
1518         pos += 4;
1519     }
1520 
1521     connection->cmd_operands_length = pos;
1522     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1523     return ERROR_CODE_SUCCESS;
1524 }
1525 
1526 uint8_t avrcp_controller_get_now_playing_info(uint16_t avrcp_cid){
1527     return avrcp_controller_get_element_attributes(avrcp_cid, 0, NULL);
1528 }
1529 
1530 uint8_t avrcp_controller_set_absolute_volume(uint16_t avrcp_cid, uint8_t volume){
1531      avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1532     if (!connection){
1533         log_error("avrcp_get_capabilities: could not find a connection.");
1534         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1535     }
1536 
1537     //
1538     // allow sending of multiple set abs volume commands without waiting for response
1539     //
1540     uint8_t status = ERROR_CODE_COMMAND_DISALLOWED;
1541     switch (connection->state){
1542         case AVCTP_CONNECTION_OPENED:
1543             status = ERROR_CODE_SUCCESS;
1544             break;
1545         case AVCTP_W2_RECEIVE_RESPONSE:
1546             // - is pending response also set abs volume
1547             if (connection->command_opcode  != AVRCP_CMD_OPCODE_VENDOR_DEPENDENT) break;
1548             if (connection->command_type    != AVRCP_CTYPE_CONTROL)               break;
1549             if (connection->subunit_type    != AVRCP_SUBUNIT_TYPE_PANEL)          break;
1550             if (connection->subunit_id      != AVRCP_SUBUNIT_ID)                  break;
1551             if (connection->cmd_operands[3] != AVRCP_PDU_ID_SET_ABSOLUTE_VOLUME)  break;
1552             // - is next transaction id valid in window
1553             if (avrcp_controller_is_transaction_id_valid(connection, avrcp_controller_calc_next_transaction_label(connection->transaction_id_counter)) == false) break;
1554             status = ERROR_CODE_SUCCESS;
1555             break;
1556         default:
1557             break;
1558     }
1559     if (status != ERROR_CODE_SUCCESS) return status;
1560 
1561     connection->state = AVCTP_W2_SEND_COMMAND;
1562 
1563     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
1564     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1565     connection->command_type = AVRCP_CTYPE_CONTROL;
1566     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1567     connection->subunit_id = AVRCP_SUBUNIT_ID;
1568     int pos = 0;
1569     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1570     pos += 3;
1571     connection->cmd_operands[pos++] = AVRCP_PDU_ID_SET_ABSOLUTE_VOLUME; // PDU ID
1572     connection->cmd_operands[pos++] = 0;
1573 
1574     // Parameter Length
1575     big_endian_store_16(connection->cmd_operands, pos, 1);
1576     pos += 2;
1577     connection->cmd_operands[pos++] = volume;
1578 
1579     connection->cmd_operands_length = pos;
1580     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1581     return ERROR_CODE_SUCCESS;
1582 }
1583 
1584 uint8_t avrcp_controller_query_shuffle_and_repeat_modes(uint16_t avrcp_cid){
1585     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1586     if (!connection){
1587         log_error("avrcp_get_capabilities: could not find a connection.");
1588         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1589     }
1590     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1591     connection->state = AVCTP_W2_SEND_COMMAND;
1592 
1593     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
1594     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1595     connection->command_type = AVRCP_CTYPE_STATUS;
1596     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1597     connection->subunit_id = AVRCP_SUBUNIT_ID;
1598     big_endian_store_24(connection->cmd_operands, 0, BT_SIG_COMPANY_ID);
1599     connection->cmd_operands[3] = AVRCP_PDU_ID_GET_CURRENT_PLAYER_APPLICATION_SETTING_VALUE; // PDU ID
1600     connection->cmd_operands[4] = 0;
1601     big_endian_store_16(connection->cmd_operands, 5, 5); // parameter length
1602     connection->cmd_operands[7] = 4;                     // NumPlayerApplicationSettingAttributeID
1603     // PlayerApplicationSettingAttributeID1 AVRCP Spec, Appendix F, 133
1604     connection->cmd_operands[8]  = 0x01;    // equalizer  (1-OFF, 2-ON)
1605     connection->cmd_operands[9]  = 0x02;    // repeat     (1-off, 2-single track, 3-all tracks, 4-group repeat)
1606     connection->cmd_operands[10] = 0x03;    // shuffle    (1-off, 2-all tracks, 3-group shuffle)
1607     connection->cmd_operands[11] = 0x04;    // scan       (1-off, 2-all tracks, 3-group scan)
1608     connection->cmd_operands_length = 12;
1609     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1610     return ERROR_CODE_SUCCESS;
1611 }
1612 
1613 static uint8_t avrcp_controller_set_current_player_application_setting_value(uint16_t avrcp_cid, uint8_t attr_id, uint8_t attr_value){
1614     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1615     if (!connection){
1616         log_error("avrcp_get_capabilities: could not find a connection.");
1617         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1618     }
1619     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1620     connection->state = AVCTP_W2_SEND_COMMAND;
1621 
1622     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
1623     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1624     connection->command_type = AVRCP_CTYPE_CONTROL;
1625     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1626     connection->subunit_id = AVRCP_SUBUNIT_ID;
1627     int pos = 0;
1628     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1629     pos += 3;
1630     connection->cmd_operands[pos++] = AVRCP_PDU_ID_SET_PLAYER_APPLICATION_SETTING_VALUE; // PDU ID
1631     connection->cmd_operands[pos++] = 0;
1632     // Parameter Length
1633     big_endian_store_16(connection->cmd_operands, pos, 3);
1634     pos += 2;
1635     connection->cmd_operands[pos++] = 2;
1636     connection->cmd_operands_length = pos;
1637     connection->cmd_operands[pos++]  = attr_id;
1638     connection->cmd_operands[pos++]  = attr_value;
1639     connection->cmd_operands_length = pos;
1640     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1641     return ERROR_CODE_SUCCESS;
1642 }
1643 
1644 uint8_t avrcp_controller_set_shuffle_mode(uint16_t avrcp_cid, avrcp_shuffle_mode_t mode){
1645     if ((mode < AVRCP_SHUFFLE_MODE_OFF) || (mode > AVRCP_SHUFFLE_MODE_GROUP)) return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
1646     return avrcp_controller_set_current_player_application_setting_value(avrcp_cid, 0x03, mode);
1647 }
1648 
1649 uint8_t avrcp_controller_set_repeat_mode(uint16_t avrcp_cid, avrcp_repeat_mode_t mode){
1650     if ((mode < AVRCP_REPEAT_MODE_OFF) || (mode > AVRCP_REPEAT_MODE_GROUP)) return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
1651     return avrcp_controller_set_current_player_application_setting_value(avrcp_cid, 0x02, mode);
1652 }
1653 
1654 uint8_t avrcp_controller_play_item_for_scope(uint16_t avrcp_cid, uint8_t * uid, uint16_t uid_counter, avrcp_browsing_scope_t scope){
1655     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1656     if (!connection){
1657         log_error("Could not find a connection with cid 0%02x.", avrcp_cid);
1658         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1659     }
1660     if (connection->state != AVCTP_CONNECTION_OPENED){
1661         log_error("Connection in wrong state, expected %d, received %d", AVCTP_CONNECTION_OPENED, connection->state);
1662         return ERROR_CODE_COMMAND_DISALLOWED;
1663     }
1664     connection->state = AVCTP_W2_SEND_COMMAND;
1665 
1666     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
1667     connection->command_type = AVRCP_CTYPE_CONTROL;
1668     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1669     connection->subunit_id = AVRCP_SUBUNIT_ID;
1670     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1671     int pos = 0;
1672     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1673     pos += 3;
1674     connection->cmd_operands[pos++] = AVRCP_PDU_ID_PLAY_ITEM; // PDU ID
1675     // reserved
1676     connection->cmd_operands[pos++] = 0;
1677     // Parameter Length
1678     big_endian_store_16(connection->cmd_operands, pos, 11);
1679     pos += 2;
1680     connection->cmd_operands[pos++]  = scope;
1681     memset(&connection->cmd_operands[pos], 0, 8);
1682     if (uid){
1683         (void)memcpy(&connection->cmd_operands[pos], uid, 8);
1684     }
1685     pos += 8;
1686     big_endian_store_16(connection->cmd_operands, pos, uid_counter);
1687     pos += 2;
1688     connection->cmd_operands_length = pos;
1689 
1690     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1691     return ERROR_CODE_SUCCESS;
1692 }
1693 
1694 uint8_t avrcp_controller_add_item_from_scope_to_now_playing_list(uint16_t avrcp_cid, uint8_t * uid, uint16_t uid_counter, avrcp_browsing_scope_t scope){
1695     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1696     if (!connection){
1697         log_error("Could not find a connection with cid 0%02x.", avrcp_cid);
1698         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1699     }
1700     if (connection->state != AVCTP_CONNECTION_OPENED){
1701         log_error("Connection in wrong state, expected %d, received %d", AVCTP_CONNECTION_OPENED, connection->state);
1702         return ERROR_CODE_COMMAND_DISALLOWED;
1703     }
1704     connection->state = AVCTP_W2_SEND_COMMAND;
1705 
1706     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
1707     connection->command_type = AVRCP_CTYPE_CONTROL;
1708     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1709     connection->subunit_id = AVRCP_SUBUNIT_ID;
1710     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1711     int pos = 0;
1712     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1713     pos += 3;
1714     connection->cmd_operands[pos++] = AVRCP_PDU_ID_ADD_TO_NOW_PLAYING; // PDU ID
1715     // reserved
1716     connection->cmd_operands[pos++] = 0;
1717     // Parameter Length
1718     big_endian_store_16(connection->cmd_operands, pos, 11);
1719     pos += 2;
1720     connection->cmd_operands[pos++]  = scope;
1721     memset(&connection->cmd_operands[pos], 0, 8);
1722     if (uid){
1723         (void)memcpy(&connection->cmd_operands[pos], uid, 8);
1724     }
1725     pos += 8;
1726     big_endian_store_16(connection->cmd_operands, pos, uid_counter);
1727     pos += 2;
1728     connection->cmd_operands_length = pos;
1729 
1730     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1731     return ERROR_CODE_SUCCESS;
1732 }
1733 
1734 uint8_t avrcp_controller_set_max_num_fragments(uint16_t avrcp_cid, uint8_t max_num_fragments){
1735     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1736     if (!connection){
1737         log_error("avrcp_controller_play_item: could not find a connection.");
1738         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1739     }
1740     connection->max_num_fragments = max_num_fragments;
1741     return ERROR_CODE_SUCCESS;
1742 }
1743 
1744 uint8_t avrcp_controller_send_custom_command(uint16_t avrcp_cid, avrcp_command_type_t command_type, avrcp_subunit_type_t subunit_type, avrcp_subunit_id_t subunit_id, avrcp_command_opcode_t command_opcode, const uint8_t * command_buffer, uint16_t command_len){
1745     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1746     if (!connection){
1747         log_error("avrcp_controller_play_item: could not find a connection.");
1748         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1749     }
1750 
1751     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1752     connection->state = AVCTP_W2_SEND_FRAGMENTED_COMMAND;
1753 
1754     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
1755     connection->command_opcode = command_opcode;
1756     connection->command_type = command_type;
1757     connection->subunit_type = subunit_type;
1758     connection->subunit_id = subunit_id;
1759     connection->cmd_operands_fragmented_buffer = command_buffer;
1760     connection->cmd_operands_fragmented_pos = 0;
1761     connection->cmd_operands_fragmented_len = command_len;
1762 
1763     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1764     return ERROR_CODE_SUCCESS;
1765 }
1766