xref: /btstack/src/classic/avrcp_controller.c (revision 66ec160393003e0a42c62d0008a7010afb04728a)
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_notification_complete(avrcp_connection_t * connection, uint8_t status, uint8_t event_id){
96     uint8_t event[7];
97     uint8_t pos = 0;
98     event[pos++] = HCI_EVENT_AVRCP_META;
99     event[pos++] = sizeof(event) - 2;
100     event[pos++] = AVRCP_SUBEVENT_ENABLE_NOTIFICATION_COMPLETE;
101     little_endian_store_16(event, pos, connection->avrcp_cid);
102     pos += 2;
103     event[pos++] = status;
104     event[pos++] = event_id;
105     UNUSED(pos);
106     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
107 }
108 
109 static void avrcp_controller_emit_supported_events(avrcp_connection_t * connection){
110     uint8_t ctype = (uint8_t) AVRCP_CTYPE_RESPONSE_CHANGED_STABLE;
111     uint8_t event_id;
112 
113     for (event_id = (uint8_t) AVRCP_NOTIFICATION_EVENT_FIRST_INDEX; event_id < (uint8_t) AVRCP_NOTIFICATION_EVENT_LAST_INDEX; event_id++){
114         if ( (connection->remote_supported_notifications & (1<<event_id)) == 0){
115             continue;
116         }
117         uint8_t event[8];
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;
122         little_endian_store_16(event, pos, connection->avrcp_cid);
123         pos += 2;
124         event[pos++] = ctype;
125         event[pos++] = 0;
126         event[pos++] = event_id;
127         UNUSED(pos);
128         (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
129     }
130 
131     uint8_t event[7];
132     uint8_t pos = 0;
133     event[pos++] = HCI_EVENT_AVRCP_META;
134     event[pos++] = sizeof(event) - 2;
135     event[pos++] = AVRCP_SUBEVENT_GET_CAPABILITY_EVENT_ID_DONE;
136     little_endian_store_16(event, pos, connection->avrcp_cid);
137     pos += 2;
138     event[pos++] = ctype;
139     event[pos++] = 0;
140     UNUSED(pos);
141     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
142 }
143 
144 static void avrcp_controller_emit_notification_for_event_id(uint16_t avrcp_cid, avrcp_notification_event_id_t event_id,
145                                                             avrcp_command_type_t ctype, const uint8_t *payload,
146                                                             uint16_t size) {
147     switch (event_id){
148         case AVRCP_NOTIFICATION_EVENT_PLAYBACK_POS_CHANGED:{
149             if (size < 4) break;
150             uint32_t song_position = big_endian_read_32(payload, 0);
151             uint16_t offset = 0;
152             uint8_t event[10];
153             event[offset++] = HCI_EVENT_AVRCP_META;
154             event[offset++] = sizeof(event) - 2;
155             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_PLAYBACK_POS_CHANGED;
156             little_endian_store_16(event, offset, avrcp_cid);
157             offset += 2;
158             event[offset++] = ctype;
159             little_endian_store_32(event, offset, song_position);
160             offset += 4;
161             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
162             break;
163         }
164         case AVRCP_NOTIFICATION_EVENT_PLAYBACK_STATUS_CHANGED:{
165             if (size < 1) break;
166             uint16_t offset = 0;
167             uint8_t event[7];
168             event[offset++] = HCI_EVENT_AVRCP_META;
169             event[offset++] = sizeof(event) - 2;
170             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_PLAYBACK_STATUS_CHANGED;
171             little_endian_store_16(event, offset, avrcp_cid);
172             offset += 2;
173             event[offset++] = ctype;
174             event[offset++] = payload[0];
175             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
176             break;
177         }
178         case AVRCP_NOTIFICATION_EVENT_TRACK_CHANGED:{
179             uint16_t offset = 0;
180             uint8_t event[6];
181             event[offset++] = HCI_EVENT_AVRCP_META;
182             event[offset++] = sizeof(event) - 2;
183             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_TRACK_CHANGED;
184             little_endian_store_16(event, offset, avrcp_cid);
185             offset += 2;
186             event[offset++] = ctype;
187             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
188             break;
189         }
190         case AVRCP_NOTIFICATION_EVENT_NOW_PLAYING_CONTENT_CHANGED:{
191             uint16_t offset = 0;
192             uint8_t event[6];
193             event[offset++] = HCI_EVENT_AVRCP_META;
194             event[offset++] = sizeof(event) - 2;
195             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_NOW_PLAYING_CONTENT_CHANGED;
196             little_endian_store_16(event, offset, avrcp_cid);
197             offset += 2;
198             event[offset++] = ctype;
199             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
200             break;
201         }
202         case AVRCP_NOTIFICATION_EVENT_AVAILABLE_PLAYERS_CHANGED:{
203             uint16_t offset = 0;
204             uint8_t event[6];
205             event[offset++] = HCI_EVENT_AVRCP_META;
206             event[offset++] = sizeof(event) - 2;
207             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_AVAILABLE_PLAYERS_CHANGED;
208             little_endian_store_16(event, offset, avrcp_cid);
209             offset += 2;
210             event[offset++] = ctype;
211             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
212             break;
213         }
214         case AVRCP_NOTIFICATION_EVENT_VOLUME_CHANGED:{
215             if (size < 1) break;
216             uint16_t offset = 0;
217             uint8_t event[7];
218             event[offset++] = HCI_EVENT_AVRCP_META;
219             event[offset++] = sizeof(event) - 2;
220             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_VOLUME_CHANGED;
221             little_endian_store_16(event, offset, avrcp_cid);
222             offset += 2;
223             event[offset++] = ctype;
224             event[offset++] = payload[0] & 0x7F;
225             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
226             break;
227         }
228         case AVRCP_NOTIFICATION_EVENT_UIDS_CHANGED:{
229             if (size < 2) break;
230             uint8_t event[8];
231             uint16_t offset = 0;
232             uint16_t uuid = big_endian_read_16(payload, 0);
233             event[offset++] = HCI_EVENT_AVRCP_META;
234             event[offset++] = sizeof(event) - 2;
235             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_UIDS_CHANGED;
236             little_endian_store_16(event, offset, avrcp_cid);
237             offset += 2;
238             event[offset++] = ctype;
239             little_endian_store_16(event, offset, uuid);
240             offset += 2;
241             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
242             break;
243         }
244 
245         case AVRCP_NOTIFICATION_EVENT_TRACK_REACHED_END:{
246             uint16_t offset = 0;
247             uint8_t event[6];
248             event[offset++] = HCI_EVENT_AVRCP_META;
249             event[offset++] = sizeof(event) - 2;
250             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_TRACK_REACHED_END;
251             little_endian_store_16(event, offset, avrcp_cid);
252             offset += 2;
253             event[offset++] = ctype;
254             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
255             break;
256         }
257         case AVRCP_NOTIFICATION_EVENT_TRACK_REACHED_START:{
258             uint16_t offset = 0;
259             uint8_t event[6];
260             event[offset++] = HCI_EVENT_AVRCP_META;
261             event[offset++] = sizeof(event) - 2;
262             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_TRACK_REACHED_START;
263             little_endian_store_16(event, offset, avrcp_cid);
264             offset += 2;
265             event[offset++] = ctype;
266             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
267             break;
268         }
269         case AVRCP_NOTIFICATION_EVENT_BATT_STATUS_CHANGED:{
270             if (size < 1) break;
271             uint16_t offset = 0;
272             uint8_t event[7];
273             event[offset++] = HCI_EVENT_AVRCP_META;
274             event[offset++] = sizeof(event) - 2;
275             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_BATT_STATUS_CHANGED;
276             little_endian_store_16(event, offset, avrcp_cid);
277             offset += 2;
278             event[offset++] = ctype;
279             event[offset++] = payload[0];
280             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
281             break;
282         }
283 
284         case AVRCP_NOTIFICATION_EVENT_SYSTEM_STATUS_CHANGED:{
285             if (size < 1) break;
286             uint16_t offset = 0;
287             uint8_t event[7];
288             event[offset++] = HCI_EVENT_AVRCP_META;
289             event[offset++] = sizeof(event) - 2;
290             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_SYSTEM_STATUS_CHANGED;
291             little_endian_store_16(event, offset, avrcp_cid);
292             offset += 2;
293             event[offset++] = ctype;
294             event[offset++] = payload[0];
295             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
296             break;
297         }
298 
299         case AVRCP_NOTIFICATION_EVENT_PLAYER_APPLICATION_SETTING_CHANGED:
300         default:
301             log_info("avrcp: not implemented");
302             break;
303     }
304 }
305 
306 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){
307     btstack_assert(callback != NULL);
308 
309     uint8_t event[8];
310     int pos = 0;
311     event[pos++] = HCI_EVENT_AVRCP_META;
312     event[pos++] = sizeof(event) - 2;
313     event[pos++] = AVRCP_SUBEVENT_SHUFFLE_AND_REPEAT_MODE;
314     little_endian_store_16(event, pos, avrcp_cid);
315     pos += 2;
316     event[pos++] = ctype;
317     event[pos++] = repeat_mode;
318     event[pos++] = shuffle_mode;
319     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
320 }
321 
322 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){
323     uint8_t event[7];
324     int pos = 0;
325     event[pos++] = HCI_EVENT_AVRCP_META;
326     event[pos++] = sizeof(event) - 2;
327     event[pos++] = AVRCP_SUBEVENT_NOW_PLAYING_INFO_DONE;
328     little_endian_store_16(event, pos, avrcp_cid);
329     pos += 2;
330     event[pos++] = ctype;
331     event[pos++] = status;
332     (*callback)(HCI_EVENT_PACKET, 0, event, pos);
333 }
334 
335 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){
336     uint8_t event[HCI_EVENT_BUFFER_SIZE];
337     int pos = 0;
338     event[pos++] = HCI_EVENT_AVRCP_META;
339     // reserve one byte for subevent type and data len
340     int data_len_pos = pos;
341     pos++;
342     int subevent_type_pos = pos;
343     pos++;
344     little_endian_store_16(event, pos, avrcp_cid);
345     pos += 2;
346     event[pos++] = ctype;
347 
348     switch (attr_id){
349         case AVRCP_MEDIA_ATTR_TITLE:
350             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TITLE_INFO;
351             event[pos++] = value_len;
352             (void)memcpy(event + pos, value, value_len);
353             break;
354         case AVRCP_MEDIA_ATTR_ARTIST:
355             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_ARTIST_INFO;
356             event[pos++] = value_len;
357             (void)memcpy(event + pos, value, value_len);
358             break;
359         case AVRCP_MEDIA_ATTR_ALBUM:
360             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_ALBUM_INFO;
361             event[pos++] = value_len;
362             (void)memcpy(event + pos, value, value_len);
363             break;
364         case AVRCP_MEDIA_ATTR_GENRE:
365             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_GENRE_INFO;
366             event[pos++] = value_len;
367             (void)memcpy(event + pos, value, value_len);
368             break;
369         case AVRCP_MEDIA_ATTR_SONG_LENGTH_MS:
370             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_SONG_LENGTH_MS_INFO;
371             if (value){
372                 little_endian_store_32(event, pos, btstack_atoi((char *)value));
373             } else {
374                 little_endian_store_32(event, pos, 0);
375             }
376             pos += 4;
377             break;
378         case AVRCP_MEDIA_ATTR_TRACK:
379             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TRACK_INFO;
380             if (value){
381                 event[pos++] = btstack_atoi((char *)value);
382             } else {
383                 event[pos++] = 0;
384             }
385             break;
386         case AVRCP_MEDIA_ATTR_TOTAL_NUM_ITEMS:
387             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TOTAL_TRACKS_INFO;
388             if (value){
389                 event[pos++] = btstack_atoi((char *)value);
390             } else {
391                 event[pos++] = 0;
392             }
393             break;
394         default:
395             break;
396     }
397     event[data_len_pos] = pos - 2;
398     (*callback)(HCI_EVENT_PACKET, 0, event, pos);
399 }
400 
401 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){
402     btstack_assert(callback != NULL);
403 
404     uint8_t event[7];
405     int pos = 0;
406     event[pos++] = HCI_EVENT_AVRCP_META;
407     event[pos++] = sizeof(event) - 2;
408     event[pos++] = subevent;
409     little_endian_store_16(event, pos, avrcp_cid);
410     pos += 2;
411     event[pos++] = ctype;
412     event[pos++] = operation_id;
413     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
414 }
415 
416 static void avrcp_parser_reset(avrcp_connection_t * connection){
417     connection->list_offset = 0;
418     connection->num_attributes = 0;
419     connection->num_parsed_attributes = 0;
420     connection->parser_attribute_header_pos = 0;
421     connection->num_received_fragments = 0;
422     connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_HEADER;
423 }
424 
425 static void avrcp_parser_process_byte(uint8_t byte, avrcp_connection_t * connection, avrcp_command_type_t ctype){
426     uint16_t attribute_total_value_len;
427     uint32_t attribute_id;
428     switch(connection->parser_state){
429         case AVRCP_PARSER_GET_ATTRIBUTE_HEADER:
430             connection->parser_attribute_header[connection->parser_attribute_header_pos++] = byte;
431             connection->list_offset++;
432 
433             if (connection->parser_attribute_header_pos < AVRCP_ATTRIBUTE_HEADER_LEN) return;
434 
435             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
436             connection->attribute_value_len = btstack_min(attribute_total_value_len, AVRCP_MAX_ATTRIBUTTE_SIZE);
437             if (connection->attribute_value_len > 0){
438                 // get ready for attribute value
439                 connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_VALUE;
440                 return;
441             }
442 
443             // emit empty attribute
444             attribute_id = big_endian_read_32(connection->parser_attribute_header, 0);
445             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);
446 
447             // done, see below
448             break;
449 
450         case AVRCP_PARSER_GET_ATTRIBUTE_VALUE:
451             connection->attribute_value[connection->attribute_value_offset++] = byte;
452             connection->list_offset++;
453 
454             if (connection->attribute_value_offset < connection->attribute_value_len) return;
455 
456             // emit (potentially partial) attribute
457             attribute_id = big_endian_read_32(connection->parser_attribute_header, 0);
458             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);
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){
462                 // ignore rest of attribute
463                 connection->parser_state = AVRCP_PARSER_IGNORE_REST_OF_ATTRIBUTE_VALUE;
464                 return;
465             }
466 
467             // done, see below
468             break;
469 
470         case AVRCP_PARSER_IGNORE_REST_OF_ATTRIBUTE_VALUE:
471             connection->attribute_value_offset++;
472             connection->list_offset++;
473 
474             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
475             if (connection->attribute_value_offset < attribute_total_value_len) return;
476 
477             // done, see below
478             break;
479 
480         default:
481             return;
482     }
483 
484     // attribute fully read, check if more to come
485     if (connection->list_offset < connection->list_size){
486         // more to come, reset parser
487         connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_HEADER;
488         connection->parser_attribute_header_pos = 0;
489         connection->attribute_value_offset = 0;
490     } else {
491         // fully done
492         avrcp_parser_reset(connection);
493         avrcp_controller_emit_now_playing_info_event_done(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, 0);
494     }
495 }
496 
497 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){
498     int i;
499     for (i=0;i<num_bytes_to_read;i++){
500         avrcp_parser_process_byte(packet[i], connection, ctype);
501     }
502 }
503 
504 
505 static int avrcp_send_cmd(avrcp_connection_t * connection, avrcp_packet_type_t packet_type){
506     uint8_t  command[AVRCP_CMD_BUFFER_SIZE];
507     uint16_t pos = 0;
508 
509     // non-fragmented: transport header (1) + PID (2)
510     // fragmented:     transport header (1) + num packets (1) + PID (2)
511 
512     // transport header : transaction label | Packet_type | C/R | IPID (1 == invalid profile identifier)
513     command[pos++] = (connection->transaction_id << 4) | (packet_type << 2) | (AVRCP_COMMAND_FRAME << 1) | 0;
514 
515     if (packet_type == AVRCP_START_PACKET){
516         // num packets: (3 bytes overhead (PID, num packets) + command) / (MTU - transport header).
517         // to get number of packets using integer division, we subtract 1 from the data e.g. len = 5, packet size 5 => need 1 packet
518         command[pos++] = ((connection->cmd_operands_fragmented_len + 3 - 1) / (AVRCP_CMD_BUFFER_SIZE - 1)) + 1;
519     }
520 
521     if ((packet_type == AVRCP_SINGLE_PACKET) || (packet_type == AVRCP_START_PACKET)){
522         // Profile IDentifier (PID)
523         command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL >> 8;
524         command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL & 0x00FF;
525 
526         // command_type
527         command[pos++] = connection->command_type;
528         // subunit_type | subunit ID
529         command[pos++] = (connection->subunit_type << 3) | connection->subunit_id;
530         // opcode
531         command[pos++] = (uint8_t)connection->command_opcode;
532     }
533 
534     if (packet_type == AVRCP_SINGLE_PACKET){
535         // operands
536         (void)memcpy(command + pos, connection->cmd_operands,
537                      connection->cmd_operands_length);
538         pos += connection->cmd_operands_length;
539     } else {
540         uint16_t bytes_free = AVRCP_CMD_BUFFER_SIZE - pos;
541         uint16_t bytes_to_store = connection->cmd_operands_fragmented_len-connection->cmd_operands_fragmented_pos;
542         uint16_t bytes_to_copy = btstack_min(bytes_to_store, bytes_free);
543         (void)memcpy(command + pos,
544                      &connection->cmd_operands_fragmented_buffer[connection->cmd_operands_fragmented_pos],
545                      bytes_to_copy);
546         pos += bytes_to_copy;
547         connection->cmd_operands_fragmented_pos += bytes_to_copy;
548     }
549 
550     return l2cap_send(connection->l2cap_signaling_cid, command, pos);
551 }
552 
553 static int avrcp_send_register_notification(avrcp_connection_t * connection, uint8_t event_id){
554     uint8_t command[18];
555     uint16_t pos = 0;
556     // transport header : transaction label | Packet_type | C/R | IPID (1 == invalid profile identifier)
557     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
558     command[pos++] = (connection->transaction_id << 4) | (AVRCP_SINGLE_PACKET << 2) | (AVRCP_COMMAND_FRAME << 1) | 0;
559 
560     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL >> 8;
561     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL & 0x00FF;
562     command[pos++] = AVRCP_CTYPE_NOTIFY;
563     command[pos++] = (AVRCP_SUBUNIT_TYPE_PANEL << 3) | AVRCP_SUBUNIT_ID;
564     command[pos++] = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
565 
566     big_endian_store_24(command, pos, BT_SIG_COMPANY_ID);
567     pos += 3;
568     command[pos++] = AVRCP_PDU_ID_REGISTER_NOTIFICATION;
569     command[pos++] = 0;                       // reserved(upper 6) | packet_type -> 0
570     big_endian_store_16(command, pos, 5);     // parameter length
571     pos += 2;
572     command[pos++] = event_id;
573     big_endian_store_32(command, pos, 1);     // send notification on playback position every second, for other notifications it is ignored
574     pos += 4;
575     return l2cap_send(connection->l2cap_signaling_cid, command, pos);
576 }
577 
578 static void avrcp_press_and_hold_timeout_handler(btstack_timer_source_t * timer){
579     UNUSED(timer);
580     avrcp_connection_t * connection = (avrcp_connection_t*) btstack_run_loop_get_timer_context(timer);
581     btstack_run_loop_set_timer(&connection->press_and_hold_cmd_timer, 2000); // 2 seconds timeout
582     btstack_run_loop_add_timer(&connection->press_and_hold_cmd_timer);
583     connection->state = AVCTP_W2_SEND_PRESS_COMMAND;
584     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
585 }
586 
587 static void avrcp_press_and_hold_timer_start(avrcp_connection_t * connection){
588     btstack_run_loop_remove_timer(&connection->press_and_hold_cmd_timer);
589     btstack_run_loop_set_timer_handler(&connection->press_and_hold_cmd_timer, avrcp_press_and_hold_timeout_handler);
590     btstack_run_loop_set_timer_context(&connection->press_and_hold_cmd_timer, connection);
591     btstack_run_loop_set_timer(&connection->press_and_hold_cmd_timer, 2000); // 2 seconds timeout
592     btstack_run_loop_add_timer(&connection->press_and_hold_cmd_timer);
593 }
594 
595 static void avrcp_press_and_hold_timer_stop(avrcp_connection_t * connection){
596     connection->press_and_hold_cmd_active = false;
597     btstack_run_loop_remove_timer(&connection->press_and_hold_cmd_timer);
598 }
599 
600 
601 static uint8_t avrcp_controller_request_pass_through_release_control_cmd(avrcp_connection_t * connection){
602     connection->state = AVCTP_W2_SEND_RELEASE_COMMAND;
603     if (connection->press_and_hold_cmd_active){
604         avrcp_press_and_hold_timer_stop(connection);
605     }
606     connection->cmd_operands[0] = 0x80 | connection->cmd_operands[0];
607     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
608     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
609     return ERROR_CODE_SUCCESS;
610 }
611 
612 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){
613     log_info("Send command %d", opid);
614     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
615     if (!connection){
616         log_error("Could not find a connection. avrcp cid 0x%02x", avrcp_cid);
617         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
618     }
619 
620     if (connection->state != AVCTP_CONNECTION_OPENED){
621         log_error("Connection in wrong state %d, expected %d. avrcp cid 0x%02x", connection->state, AVCTP_CONNECTION_OPENED, avrcp_cid);
622         return ERROR_CODE_COMMAND_DISALLOWED;
623     }
624     connection->state = AVCTP_W2_SEND_PRESS_COMMAND;
625     connection->command_opcode =  AVRCP_CMD_OPCODE_PASS_THROUGH;
626     connection->command_type = AVRCP_CTYPE_CONTROL;
627     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
628     connection->subunit_id =   AVRCP_SUBUNIT_ID;
629     connection->cmd_operands_length = 0;
630 
631     connection->press_and_hold_cmd_active = continuous_cmd;
632     connection->cmd_operands_length = 2;
633     connection->cmd_operands[0] = opid;
634     if (playback_speed > 0){
635         connection->cmd_operands[2] = playback_speed;
636         connection->cmd_operands_length++;
637     }
638     connection->cmd_operands[1] = connection->cmd_operands_length - 2;
639 
640     if (connection->press_and_hold_cmd_active){
641         avrcp_press_and_hold_timer_start(connection);
642     }
643 
644     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
645     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
646     return ERROR_CODE_SUCCESS;
647 }
648 
649 static uint8_t request_single_pass_through_press_control_cmd(uint16_t avrcp_cid, avrcp_operation_id_t opid, uint16_t playback_speed){
650     return avrcp_controller_request_pass_through_press_control_cmd(avrcp_cid, opid, playback_speed, false);
651 }
652 
653 static uint8_t request_continuous_pass_through_press_control_cmd(uint16_t avrcp_cid, avrcp_operation_id_t opid, uint16_t playback_speed){
654     return avrcp_controller_request_pass_through_press_control_cmd(avrcp_cid, opid, playback_speed, true);
655 }
656 
657 static void avrcp_controller_get_capabilities_for_connection(avrcp_connection_t * connection, uint8_t capability_id){
658     connection->state = AVCTP_W2_SEND_COMMAND;
659     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
660     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
661     connection->command_type = AVRCP_CTYPE_STATUS;
662     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
663     connection->subunit_id = AVRCP_SUBUNIT_ID;
664     big_endian_store_24(connection->cmd_operands, 0, BT_SIG_COMPANY_ID);
665     connection->cmd_operands[3] = AVRCP_PDU_ID_GET_CAPABILITIES; // PDU ID
666     connection->cmd_operands[4] = 0;
667     big_endian_store_16(connection->cmd_operands, 5, 1); // parameter length
668     connection->cmd_operands[7] = capability_id;                  // capability ID
669     connection->cmd_operands_length = 8;
670     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
671 }
672 
673 static uint8_t avrcp_controller_register_notification(avrcp_connection_t * connection, avrcp_notification_event_id_t event_id){
674     if (connection->remote_supported_notifications_queried && (connection->remote_supported_notifications & (1 << event_id)) == 0){
675         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
676     }
677     if ( (connection->notifications_to_deregister & (1 << event_id)) != 0){
678         return ERROR_CODE_COMMAND_DISALLOWED;
679     }
680     if ( (connection->notifications_enabled & (1 << event_id)) != 0){
681         return ERROR_CODE_SUCCESS;
682     }
683     connection->notifications_to_register |= (1 << event_id);
684 
685     if (!connection->remote_supported_notifications_queried){
686         connection->remote_supported_notifications_suppress_emit_result = true;
687         avrcp_controller_get_capabilities_for_connection(connection, AVRCP_CAPABILITY_ID_EVENT);
688         return ERROR_CODE_SUCCESS;
689     }
690     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
691     return ERROR_CODE_SUCCESS;
692 }
693 
694 static uint8_t avrcp_controller_request_abort_continuation(avrcp_connection_t * connection){
695     connection->state = AVCTP_W2_SEND_COMMAND;
696     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
697     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
698     connection->command_type = AVRCP_CTYPE_CONTROL;
699     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
700     connection->subunit_id = AVRCP_SUBUNIT_ID;
701     int pos = 0;
702     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
703     pos += 3;
704     connection->cmd_operands[pos++] = AVRCP_PDU_ID_REQUEST_ABORT_CONTINUING_RESPONSE; // PDU ID
705     connection->cmd_operands[pos++] = 0;
706     // Parameter Length
707     connection->cmd_operands_length = 8;
708     big_endian_store_16(connection->cmd_operands, pos, 1);
709     pos += 2;
710     connection->cmd_operands[pos++] = AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES;
711     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
712     return ERROR_CODE_SUCCESS;
713 }
714 
715 
716 static uint8_t avrcp_controller_request_continue_response(avrcp_connection_t * connection){
717     connection->state = AVCTP_W2_SEND_COMMAND;
718     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
719     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
720     connection->command_type = AVRCP_CTYPE_CONTROL;
721     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
722     connection->subunit_id = AVRCP_SUBUNIT_ID;
723     int pos = 0;
724     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
725     pos += 3;
726     connection->cmd_operands[pos++] = AVRCP_PDU_ID_REQUEST_CONTINUING_RESPONSE; // PDU ID
727     connection->cmd_operands[pos++] = 0;
728     // Parameter Length
729     connection->cmd_operands_length = 8;
730     big_endian_store_16(connection->cmd_operands, pos, 1);
731     pos += 2;
732     connection->cmd_operands[pos++] = AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES;
733     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
734     return ERROR_CODE_SUCCESS;
735 }
736 
737 static void avrcp_controller_handle_notification(avrcp_connection_t *connection, avrcp_command_type_t ctype, uint8_t *payload, uint16_t size) {
738     if (size < 1) return;
739     uint16_t pos = 0;
740     avrcp_notification_event_id_t event_id = (avrcp_notification_event_id_t) payload[pos++];
741     if ( (event_id < AVRCP_NOTIFICATION_EVENT_FIRST_INDEX) || (event_id > AVRCP_NOTIFICATION_EVENT_LAST_INDEX)){
742         return;
743     }
744 
745     uint16_t event_mask = (1 << event_id);
746     uint16_t reset_event_mask = ~event_mask;
747 
748     switch (ctype){
749         case AVRCP_CTYPE_RESPONSE_INTERIM:
750             // register as enabled
751             connection->notifications_enabled |= event_mask;
752 
753             // check if initial value is already sent
754             if ( (connection->initial_status_reported & event_mask) != 0 ){
755                 return;
756             }
757             // emit event only once, initially
758             avrcp_controller_emit_notification_complete(connection, ERROR_CODE_SUCCESS, event_id);
759             connection->initial_status_reported |= event_mask;
760             break;
761         case AVRCP_CTYPE_RESPONSE_CHANGED_STABLE:
762             // received change, event is considered de-registered
763             // we are re-enabling it automatically, if it is not
764             // explicitly disabled
765             connection->notifications_enabled &= reset_event_mask;
766             if (! (connection->notifications_to_deregister & event_mask)){
767                 avrcp_controller_register_notification(connection, event_id);
768             } else {
769                 connection->notifications_to_deregister &= reset_event_mask;
770             }
771             break;
772         default:
773             return;
774     }
775 
776     avrcp_controller_emit_notification_for_event_id(connection->avrcp_cid, event_id, ctype, payload + pos, size - pos);
777 }
778 
779 #ifdef ENABLE_AVCTP_FRAGMENTATION
780 static void avctp_reassemble_message(avrcp_connection_t * connection, avctp_packet_type_t packet_type, uint8_t *packet, uint16_t size){
781     // after header (transaction label and packet type)
782     uint16_t pos;
783     uint16_t bytes_to_store;
784 
785     switch (packet_type){
786         case AVCTP_START_PACKET:
787             if (size < 2) return;
788 
789             // store header
790             pos = 0;
791             connection->avctp_reassembly_buffer[pos] = packet[pos];
792             pos++;
793             connection->avctp_reassembly_size = pos;
794 
795             // NOTE: num packets not needed for reassembly, ignoring it does not pose security risk -> no need to store it
796             pos++;
797 
798             // PID in reassembled packet is at offset 1, it will be read later after the avctp_reassemble_message with AVCTP_END_PACKET is called
799 
800             bytes_to_store = btstack_min(size - pos, sizeof(connection->avctp_reassembly_buffer) - connection->avctp_reassembly_size);
801             memcpy(&connection->avctp_reassembly_buffer[connection->avctp_reassembly_size], &packet[pos], bytes_to_store);
802             connection->avctp_reassembly_size += bytes_to_store;
803             break;
804 
805         case AVCTP_CONTINUE_PACKET:
806         case AVCTP_END_PACKET:
807             if (size < 1) return;
808 
809             // store remaining data, ignore header
810             pos = 1;
811             bytes_to_store = btstack_min(size - pos, sizeof(connection->avctp_reassembly_buffer) - connection->avctp_reassembly_size);
812             memcpy(&connection->avctp_reassembly_buffer[connection->avctp_reassembly_size], &packet[pos], bytes_to_store);
813             connection->avctp_reassembly_size += bytes_to_store;
814             break;
815 
816         default:
817             return;
818     }
819 }
820 #endif
821 
822 static void avrcp_handle_l2cap_data_packet_for_signaling_connection(avrcp_connection_t * connection, uint8_t *packet, uint16_t size){
823     if (size < 6u) return;
824     uint8_t  pdu_id;
825     avrcp_packet_type_t  vendor_dependent_packet_type;
826 
827     uint16_t pos = 0;
828     connection->last_confirmed_transaction_id = packet[pos] >> 4;
829     avrcp_frame_type_t  frame_type =  (avrcp_frame_type_t)((packet[pos] >> 1) & 0x01);
830     avctp_packet_type_t packet_type = (avctp_packet_type_t)((packet[pos] >> 2) & 0x03);
831     pos++;
832 
833     if (frame_type != AVRCP_RESPONSE_FRAME) return;
834 
835     switch (packet_type){
836         case AVCTP_SINGLE_PACKET:
837             break;
838 
839 #ifdef ENABLE_AVCTP_FRAGMENTATION
840         case AVCTP_START_PACKET:
841         case AVCTP_CONTINUE_PACKET:
842             avctp_reassemble_message(connection, packet_type, packet, size);
843             return;
844 
845         case AVCTP_END_PACKET:
846             avctp_reassemble_message(connection, packet_type, packet, size);
847 
848             packet = connection->avctp_reassembly_buffer;
849             size   = connection->avctp_reassembly_size;
850             break;
851 #endif
852 
853         default:
854             return;
855     }
856 
857     pos += 2; // PID
858 
859     avrcp_command_type_t ctype = (avrcp_command_type_t) packet[pos++];
860 
861 #ifdef ENABLE_LOG_INFO
862     uint8_t byte_value = packet[pos];
863     avrcp_subunit_type_t subunit_type = (avrcp_subunit_type_t) (byte_value >> 3);
864     avrcp_subunit_type_t subunit_id   = (avrcp_subunit_type_t) (byte_value & 0x07);
865 #endif
866     pos++;
867 
868     uint8_t opcode = packet[pos++];
869     uint16_t param_length;
870 
871     switch (opcode){
872         case AVRCP_CMD_OPCODE_SUBUNIT_INFO:{
873             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE) return;
874             connection->state = AVCTP_CONNECTION_OPENED;
875 
876 #ifdef ENABLE_LOG_INFO
877             // page, extension code (1)
878             pos++;
879             uint8_t unit_type = packet[pos] >> 3;
880             uint8_t max_subunit_ID = packet[pos] & 0x07;
881             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);
882 #endif
883             break;
884         }
885         case AVRCP_CMD_OPCODE_UNIT_INFO:{
886             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE) return;
887             connection->state = AVCTP_CONNECTION_OPENED;
888 
889 #ifdef ENABLE_LOG_INFO
890             // byte value 7 (1)
891             pos++;
892             uint8_t unit_type = packet[pos] >> 3;
893             uint8_t unit = packet[pos] & 0x07;
894             pos++;
895             uint32_t company_id = big_endian_read_24(packet, pos);
896             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,
897                 ctype, subunit_type, subunit_id, opcode, unit_type, unit, company_id);
898 #endif
899             break;
900         }
901         case AVRCP_CMD_OPCODE_VENDOR_DEPENDENT:
902 
903             if ((size - pos) < 7) return;
904 
905             // Company ID (3)
906             pos += 3;
907             pdu_id = packet[pos++];
908             vendor_dependent_packet_type = (avrcp_packet_type_t)(packet[pos++] & 0x03);
909             param_length = big_endian_read_16(packet, pos);
910             pos += 2;
911 
912             if ((size - pos) < param_length) return;
913 
914             // handle asynchronous notifications, without changing state
915             if (pdu_id == AVRCP_PDU_ID_REGISTER_NOTIFICATION){
916                 avrcp_controller_handle_notification(connection, ctype, packet + pos, size - pos);
917                 break;
918             }
919 
920             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE){
921                 log_info("AVRCP_CMD_OPCODE_VENDOR_DEPENDENT state %d", connection->state);
922                 return;
923             }
924             connection->state = AVCTP_CONNECTION_OPENED;
925 
926             log_info("VENDOR DEPENDENT response: pdu id 0x%02x, param_length %d, status %s", pdu_id, param_length, avrcp_ctype2str(ctype));
927             switch (pdu_id){
928                 case AVRCP_PDU_ID_GET_CURRENT_PLAYER_APPLICATION_SETTING_VALUE:{
929                     uint8_t num_attributes = packet[pos++];
930                     int i;
931                     avrcp_repeat_mode_t  repeat_mode =  AVRCP_REPEAT_MODE_INVALID;
932                     avrcp_shuffle_mode_t shuffle_mode = AVRCP_SHUFFLE_MODE_INVALID;
933                     for (i = 0; i < num_attributes; i++){
934                         uint8_t attribute_id    = packet[pos++];
935                         uint8_t value = packet[pos++];
936                         switch (attribute_id){
937                             case 0x02:
938                                 repeat_mode = (avrcp_repeat_mode_t) value;
939                                 break;
940                             case 0x03:
941                                 shuffle_mode = (avrcp_shuffle_mode_t) value;
942                                 break;
943                             default:
944                                 break;
945                         }
946                     }
947                     avrcp_controller_emit_repeat_and_shuffle_mode(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, repeat_mode, shuffle_mode);
948                     break;
949                 }
950 
951                 case AVRCP_PDU_ID_SET_PLAYER_APPLICATION_SETTING_VALUE:{
952                     uint16_t offset = 0;
953                     uint8_t event[6];
954                     event[offset++] = HCI_EVENT_AVRCP_META;
955                     event[offset++] = sizeof(event) - 2;
956                     event[offset++] = AVRCP_SUBEVENT_PLAYER_APPLICATION_VALUE_RESPONSE;
957                     little_endian_store_16(event, offset, connection->avrcp_cid);
958                     offset += 2;
959                     event[offset++] = ctype;
960                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
961                     break;
962                 }
963 
964                 case AVRCP_PDU_ID_SET_ABSOLUTE_VOLUME:{
965                     uint16_t offset = 0;
966                     uint8_t event[7];
967                     event[offset++] = HCI_EVENT_AVRCP_META;
968                     event[offset++] = sizeof(event) - 2;
969                     event[offset++] = AVRCP_SUBEVENT_SET_ABSOLUTE_VOLUME_RESPONSE;
970                     little_endian_store_16(event, offset, connection->avrcp_cid);
971                     offset += 2;
972                     event[offset++] = ctype;
973                     event[offset++] = packet[pos++];
974                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
975                     break;
976                 }
977 
978                 case AVRCP_PDU_ID_GET_CAPABILITIES:{
979                     avrcp_capability_id_t capability_id = (avrcp_capability_id_t) packet[pos++];
980                     uint8_t capability_count = 0;
981                     if (param_length > 1){
982                         capability_count = packet[pos++];
983                     }
984                     uint16_t i;
985                     uint16_t offset = 0;
986                     uint8_t event[10];
987 
988                     switch (capability_id){
989 
990                         case AVRCP_CAPABILITY_ID_COMPANY:
991                             for (i = 0; (i < capability_count) && ((size - pos) >= 3); i++){
992                                 uint32_t company_id = big_endian_read_24(packet, pos);
993                                 pos += 3;
994                                 log_info("  0x%06" PRIx32 ", ", company_id);
995 
996                                 offset = 0;
997                                 event[offset++] = HCI_EVENT_AVRCP_META;
998                                 event[offset++] = sizeof(event) - 2;
999                                 event[offset++] = AVRCP_SUBEVENT_GET_CAPABILITY_COMPANY_ID;
1000                                 little_endian_store_16(event, offset, connection->avrcp_cid);
1001                                 offset += 2;
1002                                 event[offset++] = ctype;
1003                                 event[offset++] = 0;
1004                                 little_endian_store_24(event, offset, company_id);
1005                                 offset += 3;
1006                                 (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, offset);
1007                             }
1008 
1009                             offset = 0;
1010                             event[offset++] = HCI_EVENT_AVRCP_META;
1011                             event[offset++] = sizeof(event) - 2;
1012                             event[offset++] = AVRCP_SUBEVENT_GET_CAPABILITY_COMPANY_ID_DONE;
1013                             little_endian_store_16(event, offset, connection->avrcp_cid);
1014                             offset += 2;
1015                             event[offset++] = ctype;
1016                             event[offset++] = 0;
1017                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, offset);
1018                             break;
1019 
1020                         case AVRCP_CAPABILITY_ID_EVENT:
1021                             for (i = 0; (i < capability_count) && ((size - pos) >= 1); i++){
1022                                 uint8_t event_id = packet[pos++];
1023                                 connection->remote_supported_notifications |= (1 << event_id);
1024                             }
1025 
1026                             // if the get supported events query is triggered by avrcp_controller_enable_notification call,
1027                             // avrcp_controller_emit_supported_events should be suppressed
1028                             if (connection->remote_supported_notifications_suppress_emit_result){
1029                                 connection->remote_supported_notifications_suppress_emit_result = false;
1030                                 // also, notification might not be supported
1031                                 // if so, emit AVRCP_SUBEVENT_ENABLE_NOTIFICATION_COMPLETE event to app,
1032                                 // and update notifications_to_register bitmap
1033                                 for (i = (uint8_t)AVRCP_NOTIFICATION_EVENT_FIRST_INDEX; i < (uint8_t) AVRCP_NOTIFICATION_EVENT_LAST_INDEX; i++){
1034                                     if ((connection->notifications_to_register & (1<<i)) != 0){
1035                                         if ((connection->remote_supported_notifications & (1<<i)) == 0){
1036                                             avrcp_controller_emit_notification_complete(connection, ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE, i);
1037                                             connection->notifications_to_register &= ~(1 << i);
1038                                         }
1039                                     }
1040                                 }
1041                                 break;
1042                             }
1043                             // supported events are emitted only if the get supported events query
1044                             // is triggered by avrcp_controller_get_supported_events call
1045                             avrcp_controller_emit_supported_events(connection);
1046                             break;
1047 
1048                         default:
1049                             // ignore
1050                             break;
1051                     }
1052                     break;
1053                 }
1054 
1055                 case AVRCP_PDU_ID_GET_PLAY_STATUS:{
1056                     uint32_t song_length = big_endian_read_32(packet, pos);
1057                     pos += 4;
1058                     uint32_t song_position = big_endian_read_32(packet, pos);
1059                     pos += 4;
1060                     uint8_t play_status = packet[pos];
1061 
1062                     uint8_t event[15];
1063                     int offset = 0;
1064                     event[offset++] = HCI_EVENT_AVRCP_META;
1065                     event[offset++] = sizeof(event) - 2;
1066                     event[offset++] = AVRCP_SUBEVENT_PLAY_STATUS;
1067                     little_endian_store_16(event, offset, connection->avrcp_cid);
1068                     offset += 2;
1069                     event[offset++] = ctype;
1070                     little_endian_store_32(event, offset, song_length);
1071                     offset += 4;
1072                     little_endian_store_32(event, offset, song_position);
1073                     offset += 4;
1074                     event[offset++] = play_status;
1075                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
1076                     break;
1077                 }
1078 
1079                 case AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES:{
1080                     switch (vendor_dependent_packet_type){
1081                         case AVRCP_START_PACKET:
1082                         case AVRCP_SINGLE_PACKET:
1083                             avrcp_parser_reset(connection);
1084                             connection->list_size = param_length;
1085                             connection->num_attributes = packet[pos++];
1086 
1087                             avrcp_controller_parse_and_emit_element_attrs(packet+pos, size-pos, connection, ctype);
1088                             if (vendor_dependent_packet_type == AVRCP_START_PACKET){
1089                                 avrcp_controller_request_continue_response(connection);
1090                             }
1091                             break;
1092                         case AVRCP_CONTINUE_PACKET:
1093                         case AVRCP_END_PACKET:
1094                             connection->num_received_fragments++;
1095 
1096                             if (connection->num_received_fragments < connection->max_num_fragments){
1097                                 avrcp_controller_parse_and_emit_element_attrs(packet+pos, size-pos, connection, ctype);
1098 
1099                                 if (vendor_dependent_packet_type == AVRCP_CONTINUE_PACKET){
1100                                     avrcp_controller_request_continue_response(connection);
1101                                 }
1102                             } else {
1103                                 avrcp_controller_emit_now_playing_info_event_done(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, 1);
1104                                 avrcp_parser_reset(connection);
1105                                 avrcp_controller_request_abort_continuation(connection);
1106                             }
1107                             break;
1108                         default:
1109                             // TODO check
1110                             btstack_assert(false);
1111                             break;
1112                     }
1113                 }
1114                 default:
1115                     break;
1116             }
1117             break;
1118         case AVRCP_CMD_OPCODE_PASS_THROUGH:{
1119             if ((size - pos) < 1) return;
1120             uint8_t operation_id = packet[pos++];
1121             switch (connection->state){
1122                 case AVCTP_W2_RECEIVE_PRESS_RESPONSE:
1123                     // trigger release for simple command:
1124                     if (!connection->press_and_hold_cmd_active){
1125                         connection->state = AVCTP_W2_SEND_RELEASE_COMMAND;
1126                         break;
1127                     }
1128                     // for press and hold, send release if it just has been requested, otherwise, wait for next repeat
1129                     if (connection->press_and_hold_cmd_release){
1130                         connection->press_and_hold_cmd_release = false;
1131                         connection->state = AVCTP_W2_SEND_RELEASE_COMMAND;
1132                     } else {
1133                         connection->state = AVCTP_W4_STOP;
1134                     }
1135                     break;
1136                 case AVCTP_W2_RECEIVE_RESPONSE:
1137                     connection->state = AVCTP_CONNECTION_OPENED;
1138                     break;
1139                 default:
1140                     break;
1141             }
1142             if (connection->state == AVCTP_W4_STOP){
1143                 avrcp_controller_emit_operation_status(avrcp_controller_context.avrcp_callback, AVRCP_SUBEVENT_OPERATION_START, connection->avrcp_cid, ctype, operation_id);
1144             }
1145             if (connection->state == AVCTP_CONNECTION_OPENED) {
1146                 // RELEASE response
1147                 operation_id = operation_id & 0x7F;
1148                 avrcp_controller_emit_operation_status(avrcp_controller_context.avrcp_callback, AVRCP_SUBEVENT_OPERATION_COMPLETE, connection->avrcp_cid, ctype, operation_id);
1149             }
1150             if (connection->state == AVCTP_W2_SEND_RELEASE_COMMAND){
1151                 // PRESS response
1152                 avrcp_controller_request_pass_through_release_control_cmd(connection);
1153             }
1154             break;
1155         }
1156         default:
1157             break;
1158     }
1159 
1160     // trigger pending notification reqistrations
1161     if ((connection->state == AVCTP_CONNECTION_OPENED) && connection->notifications_to_register){
1162         avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1163     }
1164 }
1165 
1166 static void avrcp_controller_handle_can_send_now(avrcp_connection_t * connection){
1167     switch (connection->state){
1168         case AVCTP_W2_SEND_PRESS_COMMAND:
1169             connection->state = AVCTP_W2_RECEIVE_PRESS_RESPONSE;
1170             avrcp_send_cmd(connection, AVRCP_SINGLE_PACKET);
1171             return;
1172         case AVCTP_W2_SEND_COMMAND:
1173         case AVCTP_W2_SEND_RELEASE_COMMAND:
1174             connection->state = AVCTP_W2_RECEIVE_RESPONSE;
1175             avrcp_send_cmd(connection, AVRCP_SINGLE_PACKET);
1176             return;
1177         case AVCTP_W2_SEND_FRAGMENTED_COMMAND:
1178             if (connection->cmd_operands_fragmented_pos == 0){
1179                  avrcp_send_cmd(connection, AVRCP_START_PACKET);
1180                  avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1181             } else {
1182                 if ((connection->cmd_operands_fragmented_len - connection->cmd_operands_fragmented_pos) > avrcp_get_max_payload_size_for_packet_type(AVRCP_CONTINUE_PACKET)){
1183                      avrcp_send_cmd(connection, AVRCP_CONTINUE_PACKET);
1184                      avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1185                  } else {
1186                     connection->state = AVCTP_W2_RECEIVE_RESPONSE;
1187                     avrcp_send_cmd(connection, AVRCP_END_PACKET);
1188                  }
1189             }
1190             return;
1191         default:
1192             break;
1193     }
1194     // send register notification if queued
1195     if (connection->notifications_to_register != 0){
1196         uint8_t event_id;
1197         for (event_id = (uint8_t)AVRCP_NOTIFICATION_EVENT_FIRST_INDEX; event_id < (uint8_t)AVRCP_NOTIFICATION_EVENT_LAST_INDEX; event_id++){
1198             if (connection->notifications_to_register & (1<<event_id)){
1199                 connection->notifications_to_register &= ~ (1 << event_id);
1200                 avrcp_send_register_notification(connection, event_id);
1201                 return;
1202             }
1203         }
1204     }
1205 }
1206 
1207 static void avrcp_controller_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
1208     avrcp_connection_t * connection;
1209 
1210     switch (packet_type) {
1211         case L2CAP_DATA_PACKET:
1212             connection = avrcp_get_connection_for_l2cap_signaling_cid_for_role(AVRCP_CONTROLLER, channel);
1213             avrcp_handle_l2cap_data_packet_for_signaling_connection(connection, packet, size);
1214             break;
1215 
1216         case HCI_EVENT_PACKET:
1217             switch (hci_event_packet_get_type(packet)){
1218                 case L2CAP_EVENT_CAN_SEND_NOW:
1219                     connection = avrcp_get_connection_for_l2cap_signaling_cid_for_role(AVRCP_CONTROLLER, channel);
1220                     avrcp_controller_handle_can_send_now(connection);
1221                     break;
1222             default:
1223                 break;
1224         }
1225         default:
1226             break;
1227     }
1228 }
1229 
1230 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){
1231     avrcp_create_sdp_record(1, service, service_record_handle, avrcp_controller_supports_browsing(supported_features), supported_features, service_name, service_provider_name);
1232 }
1233 
1234 void avrcp_controller_init(void){
1235     avrcp_controller_context.role = AVRCP_CONTROLLER;
1236     avrcp_controller_context.packet_handler = avrcp_controller_packet_handler;
1237     avrcp_register_controller_packet_handler(&avrcp_controller_packet_handler);
1238 }
1239 
1240 void avrcp_controller_deinit(void){
1241     memset(&avrcp_controller_context, 0, sizeof(avrcp_context_t));
1242 }
1243 
1244 void avrcp_controller_register_packet_handler(btstack_packet_handler_t callback){
1245     btstack_assert(callback != NULL);
1246     avrcp_controller_context.avrcp_callback = callback;
1247 }
1248 
1249 
1250 uint8_t avrcp_controller_play(uint16_t avrcp_cid){
1251     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PLAY, 0);
1252 }
1253 
1254 uint8_t avrcp_controller_stop(uint16_t avrcp_cid){
1255     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_STOP, 0);
1256 }
1257 
1258 uint8_t avrcp_controller_pause(uint16_t avrcp_cid){
1259     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PAUSE, 0);
1260 }
1261 
1262 uint8_t avrcp_controller_forward(uint16_t avrcp_cid){
1263     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FORWARD, 0);
1264 }
1265 
1266 uint8_t avrcp_controller_backward(uint16_t avrcp_cid){
1267     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_BACKWARD, 0);
1268 }
1269 
1270 uint8_t avrcp_controller_volume_up(uint16_t avrcp_cid){
1271     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_UP, 0);
1272 }
1273 
1274 uint8_t avrcp_controller_volume_down(uint16_t avrcp_cid){
1275     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_DOWN, 0);
1276 }
1277 
1278 uint8_t avrcp_controller_mute(uint16_t avrcp_cid){
1279     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_MUTE, 0);
1280 }
1281 
1282 uint8_t avrcp_controller_skip(uint16_t avrcp_cid){
1283     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_SKIP, 0);
1284 }
1285 
1286 uint8_t avrcp_controller_fast_forward(uint16_t avrcp_cid){
1287     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FAST_FORWARD, 0);
1288 }
1289 
1290 uint8_t avrcp_controller_rewind(uint16_t avrcp_cid){
1291     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_REWIND, 0);
1292 }
1293 
1294 /* start continuous cmds */
1295 
1296 uint8_t avrcp_controller_start_press_and_hold_cmd(uint16_t avrcp_cid, avrcp_operation_id_t operation_id){
1297     return request_continuous_pass_through_press_control_cmd(avrcp_cid, operation_id, 0);
1298 }
1299 
1300 uint8_t avrcp_controller_press_and_hold_play(uint16_t avrcp_cid){
1301     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PLAY, 0);
1302 }
1303 uint8_t avrcp_controller_press_and_hold_stop(uint16_t avrcp_cid){
1304     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_STOP, 0);
1305 }
1306 uint8_t avrcp_controller_press_and_hold_pause(uint16_t avrcp_cid){
1307     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PAUSE, 0);
1308 }
1309 uint8_t avrcp_controller_press_and_hold_forward(uint16_t avrcp_cid){
1310     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FORWARD, 0);
1311 }
1312 uint8_t avrcp_controller_press_and_hold_backward(uint16_t avrcp_cid){
1313     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_BACKWARD, 0);
1314 }
1315 uint8_t avrcp_controller_press_and_hold_fast_forward(uint16_t avrcp_cid){
1316     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FAST_FORWARD, 0);
1317 }
1318 uint8_t avrcp_controller_press_and_hold_rewind(uint16_t avrcp_cid){
1319     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_REWIND, 0);
1320 }
1321 uint8_t avrcp_controller_press_and_hold_volume_up(uint16_t avrcp_cid){
1322     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_UP, 0);
1323 }
1324 uint8_t avrcp_controller_press_and_hold_volume_down(uint16_t avrcp_cid){
1325     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_DOWN, 0);
1326 }
1327 uint8_t avrcp_controller_press_and_hold_mute(uint16_t avrcp_cid){
1328     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_MUTE, 0);
1329 }
1330 
1331 /* stop continuous cmds */
1332 uint8_t avrcp_controller_release_press_and_hold_cmd(uint16_t avrcp_cid){
1333     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1334     if (!connection){
1335         log_error("avrcp_stop_play: could not find a connection.");
1336         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1337     }
1338 
1339     switch (connection->state){
1340         // respond when we receive response for (repeated) press command
1341         case AVCTP_W2_RECEIVE_PRESS_RESPONSE:
1342             connection->press_and_hold_cmd_release = true;
1343             break;
1344 
1345         // release already sent or on the way, nothing to do
1346         case AVCTP_W2_RECEIVE_RESPONSE:
1347         case AVCTP_W2_SEND_RELEASE_COMMAND:
1348             break;
1349 
1350         // about to send next repeated press command or wait for it -> release right away
1351         case AVCTP_W2_SEND_PRESS_COMMAND:
1352         case AVCTP_W4_STOP:
1353             return avrcp_controller_request_pass_through_release_control_cmd(connection);
1354 
1355         // otherwise reject request
1356         default:
1357             return ERROR_CODE_COMMAND_DISALLOWED;
1358     }
1359     return ERROR_CODE_SUCCESS;
1360 }
1361 
1362 uint8_t avrcp_controller_enable_notification(uint16_t avrcp_cid, avrcp_notification_event_id_t event_id){
1363     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1364     if (!connection){
1365         log_error("avrcp_get_play_status: could not find a connection.");
1366         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1367     }
1368     return avrcp_controller_register_notification(connection, event_id);
1369 }
1370 
1371 uint8_t avrcp_controller_disable_notification(uint16_t avrcp_cid, avrcp_notification_event_id_t event_id){
1372     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1373     if (!connection){
1374         log_error("avrcp_get_play_status: could not find a connection.");
1375         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1376     }
1377     connection->notifications_to_deregister |= (1 << event_id);
1378     return ERROR_CODE_SUCCESS;
1379 }
1380 
1381 uint8_t avrcp_controller_unit_info(uint16_t avrcp_cid){
1382     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1383     if (!connection){
1384         log_error("avrcp_unit_info: could not find a connection.");
1385         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1386     }
1387     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1388     connection->state = AVCTP_W2_SEND_COMMAND;
1389 
1390     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
1391     connection->command_opcode = AVRCP_CMD_OPCODE_UNIT_INFO;
1392     connection->command_type = AVRCP_CTYPE_STATUS;
1393     connection->subunit_type = AVRCP_SUBUNIT_TYPE_UNIT; //vendor unique
1394     connection->subunit_id =   AVRCP_SUBUNIT_ID_IGNORE;
1395     memset(connection->cmd_operands, 0xFF, connection->cmd_operands_length);
1396     connection->cmd_operands_length = 5;
1397     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1398     return ERROR_CODE_SUCCESS;
1399 }
1400 
1401 uint8_t avrcp_controller_subunit_info(uint16_t avrcp_cid){
1402     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1403     if (!connection){
1404         log_error("avrcp_unit_info: could not find a connection.");
1405         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1406     }
1407     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1408     connection->state = AVCTP_W2_SEND_COMMAND;
1409 
1410     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
1411     connection->command_opcode = AVRCP_CMD_OPCODE_SUBUNIT_INFO;
1412     connection->command_type = AVRCP_CTYPE_STATUS;
1413     connection->subunit_type = AVRCP_SUBUNIT_TYPE_UNIT; //vendor unique
1414     connection->subunit_id =   AVRCP_SUBUNIT_ID_IGNORE;
1415     memset(connection->cmd_operands, 0xFF, connection->cmd_operands_length);
1416     connection->cmd_operands[0] = 7; // page: 0, extention_code: 7
1417     connection->cmd_operands_length = 5;
1418     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1419     return ERROR_CODE_SUCCESS;
1420 }
1421 
1422 uint8_t avrcp_controller_get_supported_company_ids(uint16_t avrcp_cid){
1423     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1424     if (!connection){
1425         log_error("avrcp_get_capabilities: could not find a connection.");
1426         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1427     }
1428     if (connection->state != AVCTP_CONNECTION_OPENED){
1429         return ERROR_CODE_COMMAND_DISALLOWED;
1430     }
1431     avrcp_controller_get_capabilities_for_connection(connection, AVRCP_CAPABILITY_ID_COMPANY);
1432     return ERROR_CODE_SUCCESS;
1433 }
1434 
1435 uint8_t avrcp_controller_get_supported_events(uint16_t avrcp_cid){
1436     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1437     if (!connection){
1438         log_error("avrcp_get_capabilities: could not find a connection.");
1439         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1440     }
1441     if (connection->state != AVCTP_CONNECTION_OPENED){
1442         return ERROR_CODE_COMMAND_DISALLOWED;
1443     }
1444 
1445     if (!connection->remote_supported_notifications_queried){
1446         connection->remote_supported_notifications_queried = true;
1447         avrcp_controller_get_capabilities_for_connection(connection, AVRCP_CAPABILITY_ID_EVENT);
1448         return ERROR_CODE_SUCCESS;
1449     }
1450 
1451     avrcp_controller_emit_supported_events(connection);
1452     return ERROR_CODE_SUCCESS;
1453 }
1454 
1455 uint8_t avrcp_controller_get_play_status(uint16_t avrcp_cid){
1456     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1457     if (!connection){
1458         log_error("avrcp_get_play_status: could not find a connection.");
1459         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1460     }
1461     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1462     connection->state = AVCTP_W2_SEND_COMMAND;
1463     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
1464     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1465     connection->command_type = AVRCP_CTYPE_STATUS;
1466     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1467     connection->subunit_id = AVRCP_SUBUNIT_ID;
1468     big_endian_store_24(connection->cmd_operands, 0, BT_SIG_COMPANY_ID);
1469     connection->cmd_operands[3] = AVRCP_PDU_ID_GET_PLAY_STATUS;
1470     connection->cmd_operands[4] = 0;                     // reserved(upper 6) | packet_type -> 0
1471     big_endian_store_16(connection->cmd_operands, 5, 0); // parameter length
1472     connection->cmd_operands_length = 7;
1473     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1474     return ERROR_CODE_SUCCESS;
1475 }
1476 
1477 uint8_t avrcp_controller_set_addressed_player(uint16_t avrcp_cid, uint16_t addressed_player_id){
1478     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1479     if (!connection){
1480         log_error("avrcp_get_capabilities: could not find a connection.");
1481         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1482     }
1483     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1484     connection->state = AVCTP_W2_SEND_COMMAND;
1485 
1486     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
1487     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1488     connection->command_type = AVRCP_CTYPE_CONTROL;
1489     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1490     connection->subunit_id = AVRCP_SUBUNIT_ID;
1491     int pos = 0;
1492     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1493     pos += 3;
1494     connection->cmd_operands[pos++] = AVRCP_PDU_ID_SET_ADDRESSED_PLAYER; // PDU ID
1495     connection->cmd_operands[pos++] = 0;
1496 
1497     // Parameter Length
1498     big_endian_store_16(connection->cmd_operands, pos, 2);
1499     pos += 2;
1500 
1501     big_endian_store_16(connection->cmd_operands, pos, addressed_player_id);
1502     pos += 2;
1503 
1504     connection->cmd_operands_length = pos;
1505     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1506     return ERROR_CODE_SUCCESS;
1507 }
1508 
1509 uint8_t avrcp_controller_get_element_attributes(uint16_t avrcp_cid, uint8_t num_attributes, avrcp_media_attribute_id_t * attributes){
1510     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1511     if (!connection){
1512         log_error("avrcp_get_capabilities: could not find a connection.");
1513         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1514     }
1515 
1516     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1517 
1518     if (num_attributes >= AVRCP_MEDIA_ATTR_RESERVED) {
1519         return ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS;
1520     }
1521     connection->state = AVCTP_W2_SEND_COMMAND;
1522 
1523     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
1524     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1525     connection->command_type = AVRCP_CTYPE_STATUS;
1526     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1527     connection->subunit_id = AVRCP_SUBUNIT_ID;
1528     int pos = 0;
1529     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1530     pos += 3;
1531     connection->cmd_operands[pos++] = AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES; // PDU ID
1532     connection->cmd_operands[pos++] = 0;
1533 
1534     // Parameter Length
1535     big_endian_store_16(connection->cmd_operands, pos, 9);
1536     pos += 2;
1537 
1538     // write 8 bytes value
1539     memset(connection->cmd_operands + pos, 0, 8); // identifier: PLAYING
1540     pos += 8;
1541 
1542     connection->cmd_operands[pos++] = num_attributes; // attribute count, if 0 get all attributes
1543 
1544     int i;
1545     for (i = 0; i < num_attributes; i++){
1546         // every attribute is 4 bytes long
1547         big_endian_store_32(connection->cmd_operands, pos, attributes[i]);
1548         pos += 4;
1549     }
1550 
1551     connection->cmd_operands_length = pos;
1552     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1553     return ERROR_CODE_SUCCESS;
1554 }
1555 
1556 uint8_t avrcp_controller_get_now_playing_info(uint16_t avrcp_cid){
1557     return avrcp_controller_get_element_attributes(avrcp_cid, 0, NULL);
1558 }
1559 
1560 uint8_t avrcp_controller_set_absolute_volume(uint16_t avrcp_cid, uint8_t volume){
1561      avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1562     if (!connection){
1563         log_error("avrcp_get_capabilities: could not find a connection.");
1564         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1565     }
1566 
1567     //
1568     // allow sending of multiple set abs volume commands without waiting for response
1569     //
1570     uint8_t status = ERROR_CODE_COMMAND_DISALLOWED;
1571     switch (connection->state){
1572         case AVCTP_CONNECTION_OPENED:
1573             status = ERROR_CODE_SUCCESS;
1574             break;
1575         case AVCTP_W2_RECEIVE_RESPONSE:
1576             // - is pending response also set abs volume
1577             if (connection->command_opcode  != AVRCP_CMD_OPCODE_VENDOR_DEPENDENT) break;
1578             if (connection->command_type    != AVRCP_CTYPE_CONTROL)               break;
1579             if (connection->subunit_type    != AVRCP_SUBUNIT_TYPE_PANEL)          break;
1580             if (connection->subunit_id      != AVRCP_SUBUNIT_ID)                  break;
1581             if (connection->cmd_operands[3] != AVRCP_PDU_ID_SET_ABSOLUTE_VOLUME)  break;
1582             // - is next transaction id valid in window
1583             if (avrcp_controller_is_transaction_id_valid(connection, avrcp_controller_calc_next_transaction_label(connection->transaction_id_counter)) == false) break;
1584             status = ERROR_CODE_SUCCESS;
1585             break;
1586         default:
1587             break;
1588     }
1589     if (status != ERROR_CODE_SUCCESS) return status;
1590 
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_CONTROL;
1596     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1597     connection->subunit_id = AVRCP_SUBUNIT_ID;
1598     int pos = 0;
1599     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1600     pos += 3;
1601     connection->cmd_operands[pos++] = AVRCP_PDU_ID_SET_ABSOLUTE_VOLUME; // PDU ID
1602     connection->cmd_operands[pos++] = 0;
1603 
1604     // Parameter Length
1605     big_endian_store_16(connection->cmd_operands, pos, 1);
1606     pos += 2;
1607     connection->cmd_operands[pos++] = volume;
1608 
1609     connection->cmd_operands_length = pos;
1610     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1611     return ERROR_CODE_SUCCESS;
1612 }
1613 
1614 uint8_t avrcp_controller_query_shuffle_and_repeat_modes(uint16_t avrcp_cid){
1615     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1616     if (!connection){
1617         log_error("avrcp_get_capabilities: could not find a connection.");
1618         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1619     }
1620     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1621     connection->state = AVCTP_W2_SEND_COMMAND;
1622 
1623     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
1624     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1625     connection->command_type = AVRCP_CTYPE_STATUS;
1626     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1627     connection->subunit_id = AVRCP_SUBUNIT_ID;
1628     big_endian_store_24(connection->cmd_operands, 0, BT_SIG_COMPANY_ID);
1629     connection->cmd_operands[3] = AVRCP_PDU_ID_GET_CURRENT_PLAYER_APPLICATION_SETTING_VALUE; // PDU ID
1630     connection->cmd_operands[4] = 0;
1631     big_endian_store_16(connection->cmd_operands, 5, 5); // parameter length
1632     connection->cmd_operands[7] = 4;                     // NumPlayerApplicationSettingAttributeID
1633     // PlayerApplicationSettingAttributeID1 AVRCP Spec, Appendix F, 133
1634     connection->cmd_operands[8]  = 0x01;    // equalizer  (1-OFF, 2-ON)
1635     connection->cmd_operands[9]  = 0x02;    // repeat     (1-off, 2-single track, 3-all tracks, 4-group repeat)
1636     connection->cmd_operands[10] = 0x03;    // shuffle    (1-off, 2-all tracks, 3-group shuffle)
1637     connection->cmd_operands[11] = 0x04;    // scan       (1-off, 2-all tracks, 3-group scan)
1638     connection->cmd_operands_length = 12;
1639     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1640     return ERROR_CODE_SUCCESS;
1641 }
1642 
1643 static uint8_t avrcp_controller_set_current_player_application_setting_value(uint16_t avrcp_cid, uint8_t attr_id, uint8_t attr_value){
1644     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1645     if (!connection){
1646         log_error("avrcp_get_capabilities: could not find a connection.");
1647         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1648     }
1649     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1650     connection->state = AVCTP_W2_SEND_COMMAND;
1651 
1652     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
1653     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1654     connection->command_type = AVRCP_CTYPE_CONTROL;
1655     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1656     connection->subunit_id = AVRCP_SUBUNIT_ID;
1657     int pos = 0;
1658     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1659     pos += 3;
1660     connection->cmd_operands[pos++] = AVRCP_PDU_ID_SET_PLAYER_APPLICATION_SETTING_VALUE; // PDU ID
1661     connection->cmd_operands[pos++] = 0;
1662     // Parameter Length
1663     big_endian_store_16(connection->cmd_operands, pos, 3);
1664     pos += 2;
1665     connection->cmd_operands[pos++] = 2;
1666     connection->cmd_operands_length = pos;
1667     connection->cmd_operands[pos++]  = attr_id;
1668     connection->cmd_operands[pos++]  = attr_value;
1669     connection->cmd_operands_length = pos;
1670     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1671     return ERROR_CODE_SUCCESS;
1672 }
1673 
1674 uint8_t avrcp_controller_set_shuffle_mode(uint16_t avrcp_cid, avrcp_shuffle_mode_t mode){
1675     if ((mode < AVRCP_SHUFFLE_MODE_OFF) || (mode > AVRCP_SHUFFLE_MODE_GROUP)) return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
1676     return avrcp_controller_set_current_player_application_setting_value(avrcp_cid, 0x03, mode);
1677 }
1678 
1679 uint8_t avrcp_controller_set_repeat_mode(uint16_t avrcp_cid, avrcp_repeat_mode_t mode){
1680     if ((mode < AVRCP_REPEAT_MODE_OFF) || (mode > AVRCP_REPEAT_MODE_GROUP)) return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
1681     return avrcp_controller_set_current_player_application_setting_value(avrcp_cid, 0x02, mode);
1682 }
1683 
1684 uint8_t avrcp_controller_play_item_for_scope(uint16_t avrcp_cid, uint8_t * uid, uint16_t uid_counter, avrcp_browsing_scope_t scope){
1685     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1686     if (!connection){
1687         log_error("Could not find a connection with cid 0%02x.", avrcp_cid);
1688         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1689     }
1690     if (connection->state != AVCTP_CONNECTION_OPENED){
1691         log_error("Connection in wrong state, expected %d, received %d", AVCTP_CONNECTION_OPENED, connection->state);
1692         return ERROR_CODE_COMMAND_DISALLOWED;
1693     }
1694     connection->state = AVCTP_W2_SEND_COMMAND;
1695 
1696     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
1697     connection->command_type = AVRCP_CTYPE_CONTROL;
1698     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1699     connection->subunit_id = AVRCP_SUBUNIT_ID;
1700     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1701     int pos = 0;
1702     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1703     pos += 3;
1704     connection->cmd_operands[pos++] = AVRCP_PDU_ID_PLAY_ITEM; // PDU ID
1705     // reserved
1706     connection->cmd_operands[pos++] = 0;
1707     // Parameter Length
1708     big_endian_store_16(connection->cmd_operands, pos, 11);
1709     pos += 2;
1710     connection->cmd_operands[pos++]  = scope;
1711     memset(&connection->cmd_operands[pos], 0, 8);
1712     if (uid){
1713         (void)memcpy(&connection->cmd_operands[pos], uid, 8);
1714     }
1715     pos += 8;
1716     big_endian_store_16(connection->cmd_operands, pos, uid_counter);
1717     pos += 2;
1718     connection->cmd_operands_length = pos;
1719 
1720     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1721     return ERROR_CODE_SUCCESS;
1722 }
1723 
1724 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){
1725     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1726     if (!connection){
1727         log_error("Could not find a connection with cid 0%02x.", avrcp_cid);
1728         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1729     }
1730     if (connection->state != AVCTP_CONNECTION_OPENED){
1731         log_error("Connection in wrong state, expected %d, received %d", AVCTP_CONNECTION_OPENED, connection->state);
1732         return ERROR_CODE_COMMAND_DISALLOWED;
1733     }
1734     connection->state = AVCTP_W2_SEND_COMMAND;
1735 
1736     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
1737     connection->command_type = AVRCP_CTYPE_CONTROL;
1738     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1739     connection->subunit_id = AVRCP_SUBUNIT_ID;
1740     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1741     int pos = 0;
1742     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1743     pos += 3;
1744     connection->cmd_operands[pos++] = AVRCP_PDU_ID_ADD_TO_NOW_PLAYING; // PDU ID
1745     // reserved
1746     connection->cmd_operands[pos++] = 0;
1747     // Parameter Length
1748     big_endian_store_16(connection->cmd_operands, pos, 11);
1749     pos += 2;
1750     connection->cmd_operands[pos++]  = scope;
1751     memset(&connection->cmd_operands[pos], 0, 8);
1752     if (uid){
1753         (void)memcpy(&connection->cmd_operands[pos], uid, 8);
1754     }
1755     pos += 8;
1756     big_endian_store_16(connection->cmd_operands, pos, uid_counter);
1757     pos += 2;
1758     connection->cmd_operands_length = pos;
1759 
1760     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1761     return ERROR_CODE_SUCCESS;
1762 }
1763 
1764 uint8_t avrcp_controller_set_max_num_fragments(uint16_t avrcp_cid, uint8_t max_num_fragments){
1765     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1766     if (!connection){
1767         log_error("avrcp_controller_play_item: could not find a connection.");
1768         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1769     }
1770     connection->max_num_fragments = max_num_fragments;
1771     return ERROR_CODE_SUCCESS;
1772 }
1773 
1774 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){
1775     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1776     if (!connection){
1777         log_error("avrcp_controller_play_item: could not find a connection.");
1778         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1779     }
1780 
1781     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1782     connection->state = AVCTP_W2_SEND_FRAGMENTED_COMMAND;
1783 
1784     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
1785     connection->command_opcode = command_opcode;
1786     connection->command_type = command_type;
1787     connection->subunit_type = subunit_type;
1788     connection->subunit_id = subunit_id;
1789     connection->cmd_operands_fragmented_buffer = command_buffer;
1790     connection->cmd_operands_fragmented_pos = 0;
1791     connection->cmd_operands_fragmented_len = command_len;
1792 
1793     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1794     return ERROR_CODE_SUCCESS;
1795 }
1796