xref: /btstack/src/classic/avrcp_controller.c (revision 16dc7cb4a080c8d4449424087cb52a86935e8b85)
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 "btstack.h"
45 #include "classic/avrcp.h"
46 #include "classic/avrcp_controller.h"
47 
48 #define AVRCP_CMD_BUFFER_SIZE 30
49 
50 // made public in avrcp_controller.h
51 avrcp_context_t avrcp_controller_context;
52 
53 static uint16_t avrcp_get_max_payload_size_for_packet_type(avrcp_packet_type_t packet_type){
54     switch (packet_type){
55         case AVRCP_SINGLE_PACKET:
56             return AVRCP_CMD_BUFFER_SIZE - 3;
57         case AVRCP_START_PACKET:
58             return AVRCP_CMD_BUFFER_SIZE - 4;
59         case AVRCP_CONTINUE_PACKET:
60         case AVRCP_END_PACKET:
61             return AVRCP_CMD_BUFFER_SIZE - 1;
62     }
63     return 0;
64 }
65 
66 static int avrcp_controller_supports_browsing(uint16_t controller_supported_features){
67     return controller_supported_features & AVRCP_FEATURE_MASK_BROWSING;
68 }
69 
70 static void avrcp_controller_emit_notification_for_event_id(uint16_t avrcp_cid, avrcp_notification_event_id_t event_id, avrcp_command_type_t ctype, const uint8_t * payload){
71     switch (event_id){
72         case AVRCP_NOTIFICATION_EVENT_PLAYBACK_POS_CHANGED:{
73             uint32_t song_position = big_endian_read_32(payload, 0);
74             uint16_t offset = 0;
75             uint8_t event[10];
76             event[offset++] = HCI_EVENT_AVRCP_META;
77             event[offset++] = sizeof(event) - 2;
78             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_PLAYBACK_POS_CHANGED;
79             little_endian_store_16(event, offset, avrcp_cid);
80             offset += 2;
81             event[offset++] = ctype;
82             little_endian_store_32(event, offset, song_position);
83             offset += 4;
84             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
85             break;
86         }
87         case AVRCP_NOTIFICATION_EVENT_PLAYBACK_STATUS_CHANGED:{
88             uint16_t offset = 0;
89             uint8_t event[7];
90             event[offset++] = HCI_EVENT_AVRCP_META;
91             event[offset++] = sizeof(event) - 2;
92             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_PLAYBACK_STATUS_CHANGED;
93             little_endian_store_16(event, offset, avrcp_cid);
94             offset += 2;
95             event[offset++] = ctype;
96             event[offset++] = payload[0];
97             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
98             break;
99         }
100         case AVRCP_NOTIFICATION_EVENT_TRACK_CHANGED:{
101             uint16_t offset = 0;
102             uint8_t event[6];
103             event[offset++] = HCI_EVENT_AVRCP_META;
104             event[offset++] = sizeof(event) - 2;
105             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_TRACK_CHANGED;
106             little_endian_store_16(event, offset, avrcp_cid);
107             offset += 2;
108             event[offset++] = ctype;
109             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
110             break;
111         }
112         case AVRCP_NOTIFICATION_EVENT_NOW_PLAYING_CONTENT_CHANGED:{
113             uint16_t offset = 0;
114             uint8_t event[6];
115             event[offset++] = HCI_EVENT_AVRCP_META;
116             event[offset++] = sizeof(event) - 2;
117             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_NOW_PLAYING_CONTENT_CHANGED;
118             little_endian_store_16(event, offset, avrcp_cid);
119             offset += 2;
120             event[offset++] = ctype;
121             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
122             break;
123         }
124         case AVRCP_NOTIFICATION_EVENT_AVAILABLE_PLAYERS_CHANGED:{
125             uint16_t offset = 0;
126             uint8_t event[6];
127             event[offset++] = HCI_EVENT_AVRCP_META;
128             event[offset++] = sizeof(event) - 2;
129             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_AVAILABLE_PLAYERS_CHANGED;
130             little_endian_store_16(event, offset, avrcp_cid);
131             offset += 2;
132             event[offset++] = ctype;
133             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
134             break;
135         }
136         case AVRCP_NOTIFICATION_EVENT_VOLUME_CHANGED:{
137             uint16_t offset = 0;
138             uint8_t event[7];
139             event[offset++] = HCI_EVENT_AVRCP_META;
140             event[offset++] = sizeof(event) - 2;
141             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_VOLUME_CHANGED;
142             little_endian_store_16(event, offset, avrcp_cid);
143             offset += 2;
144             event[offset++] = ctype;
145             event[offset++] = payload[0] & 0x7F;
146             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
147             break;
148         }
149         case AVRCP_NOTIFICATION_EVENT_UIDS_CHANGED:{
150             uint8_t event[8];
151             uint16_t offset = 0;
152             uint16_t uuid = big_endian_read_16(payload, 0);
153             event[offset++] = HCI_EVENT_AVRCP_META;
154             event[offset++] = sizeof(event) - 2;
155             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_UIDS_CHANGED;
156             little_endian_store_16(event, offset, avrcp_cid);
157             offset += 2;
158             event[offset++] = ctype;
159             little_endian_store_16(event, offset, uuid);
160             offset += 2;
161             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
162             break;
163         }
164 
165         case AVRCP_NOTIFICATION_EVENT_TRACK_REACHED_END:{
166             uint16_t offset = 0;
167             uint8_t event[6];
168             event[offset++] = HCI_EVENT_AVRCP_META;
169             event[offset++] = sizeof(event) - 2;
170             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_TRACK_REACHED_END;
171             little_endian_store_16(event, offset, avrcp_cid);
172             offset += 2;
173             event[offset++] = ctype;
174             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
175             break;
176         }
177         case AVRCP_NOTIFICATION_EVENT_TRACK_REACHED_START:{
178             uint16_t offset = 0;
179             uint8_t event[6];
180             event[offset++] = HCI_EVENT_AVRCP_META;
181             event[offset++] = sizeof(event) - 2;
182             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_TRACK_REACHED_START;
183             little_endian_store_16(event, offset, avrcp_cid);
184             offset += 2;
185             event[offset++] = ctype;
186             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
187             break;
188         }
189         case AVRCP_NOTIFICATION_EVENT_BATT_STATUS_CHANGED:{
190             uint16_t offset = 0;
191             uint8_t event[7];
192             event[offset++] = HCI_EVENT_AVRCP_META;
193             event[offset++] = sizeof(event) - 2;
194             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_BATT_STATUS_CHANGED;
195             little_endian_store_16(event, offset, avrcp_cid);
196             offset += 2;
197             event[offset++] = ctype;
198             event[offset++] = payload[0];
199             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
200             break;
201         }
202 
203         case AVRCP_NOTIFICATION_EVENT_SYSTEM_STATUS_CHANGED:{
204             uint16_t offset = 0;
205             uint8_t event[7];
206             event[offset++] = HCI_EVENT_AVRCP_META;
207             event[offset++] = sizeof(event) - 2;
208             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_SYSTEM_STATUS_CHANGED;
209             little_endian_store_16(event, offset, avrcp_cid);
210             offset += 2;
211             event[offset++] = ctype;
212             event[offset++] = payload[0];
213             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
214             break;
215         }
216 
217         case AVRCP_NOTIFICATION_EVENT_PLAYER_APPLICATION_SETTING_CHANGED:
218         default:
219             log_info("avrcp: not implemented");
220             break;
221     }
222 }
223 
224 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){
225     btstack_assert(callback != NULL);
226 
227     uint8_t event[8];
228     int pos = 0;
229     event[pos++] = HCI_EVENT_AVRCP_META;
230     event[pos++] = sizeof(event) - 2;
231     event[pos++] = AVRCP_SUBEVENT_SHUFFLE_AND_REPEAT_MODE;
232     little_endian_store_16(event, pos, avrcp_cid);
233     pos += 2;
234     event[pos++] = ctype;
235     event[pos++] = repeat_mode;
236     event[pos++] = shuffle_mode;
237     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
238 }
239 
240 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){
241     uint8_t event[7];
242     int pos = 0;
243     event[pos++] = HCI_EVENT_AVRCP_META;
244     event[pos++] = sizeof(event) - 2;
245     event[pos++] = AVRCP_SUBEVENT_NOW_PLAYING_INFO_DONE;
246     little_endian_store_16(event, pos, avrcp_cid);
247     pos += 2;
248     event[pos++] = ctype;
249     event[pos++] = status;
250     // printf_hexdump(event, pos);
251     (*callback)(HCI_EVENT_PACKET, 0, event, pos);
252 }
253 
254 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){
255     uint8_t event[HCI_EVENT_BUFFER_SIZE];
256     int pos = 0;
257     event[pos++] = HCI_EVENT_AVRCP_META;
258     // reserve one byte for subevent type and data len
259     int data_len_pos = pos;
260     pos++;
261     int subevent_type_pos = pos;
262     pos++;
263     little_endian_store_16(event, pos, avrcp_cid);
264     pos += 2;
265     event[pos++] = ctype;
266 
267     switch (attr_id){
268         case AVRCP_MEDIA_ATTR_TITLE:
269             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TITLE_INFO;
270             event[pos++] = value_len;
271             (void)memcpy(event + pos, value, value_len);
272             break;
273         case AVRCP_MEDIA_ATTR_ARTIST:
274             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_ARTIST_INFO;
275             event[pos++] = value_len;
276             (void)memcpy(event + pos, value, value_len);
277             break;
278         case AVRCP_MEDIA_ATTR_ALBUM:
279             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_ALBUM_INFO;
280             event[pos++] = value_len;
281             (void)memcpy(event + pos, value, value_len);
282             break;
283         case AVRCP_MEDIA_ATTR_GENRE:
284             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_GENRE_INFO;
285             event[pos++] = value_len;
286             (void)memcpy(event + pos, value, value_len);
287             break;
288         case AVRCP_MEDIA_ATTR_SONG_LENGTH_MS:
289             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_SONG_LENGTH_MS_INFO;
290             if (value){
291                 little_endian_store_32(event, pos, btstack_atoi((char *)value));
292             } else {
293                 little_endian_store_32(event, pos, 0);
294             }
295             pos += 4;
296             break;
297         case AVRCP_MEDIA_ATTR_TRACK:
298             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TRACK_INFO;
299             if (value){
300                 event[pos++] = btstack_atoi((char *)value);
301             } else {
302                 event[pos++] = 0;
303             }
304             break;
305         case AVRCP_MEDIA_ATTR_TOTAL_NUM_ITEMS:
306             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TOTAL_TRACKS_INFO;
307             if (value){
308                 event[pos++] = btstack_atoi((char *)value);
309             } else {
310                 event[pos++] = 0;
311             }
312             break;
313         default:
314             break;
315     }
316     event[data_len_pos] = pos - 2;
317     (*callback)(HCI_EVENT_PACKET, 0, event, pos);
318 }
319 
320 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){
321     btstack_assert(callback != NULL);
322 
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++] = subevent;
328     little_endian_store_16(event, pos, avrcp_cid);
329     pos += 2;
330     event[pos++] = ctype;
331     event[pos++] = operation_id;
332     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
333 }
334 
335 static void avrcp_parser_reset(avrcp_connection_t * connection){
336     connection->list_offset = 0;
337     connection->num_attributes = 0;
338     connection->num_parsed_attributes = 0;
339     connection->parser_attribute_header_pos = 0;
340     connection->num_received_fragments = 0;
341     connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_HEADER;
342 }
343 
344 static void avrcp_parser_process_byte(uint8_t byte, avrcp_connection_t * connection, avrcp_command_type_t ctype){
345     uint16_t attribute_total_value_len;
346     uint32_t attribute_id;
347     // printf("avrcp_parser_process_byte: %02x, state %02x\n", byte, connection->parser_state);
348     switch(connection->parser_state){
349         case AVRCP_PARSER_GET_ATTRIBUTE_HEADER:
350             connection->parser_attribute_header[connection->parser_attribute_header_pos++] = byte;
351             connection->list_offset++;
352 
353             if (connection->parser_attribute_header_pos < AVRCP_ATTRIBUTE_HEADER_LEN) return;
354 
355             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
356             connection->attribute_value_len = btstack_min(attribute_total_value_len, AVRCP_MAX_ATTRIBUTTE_SIZE);
357             if (connection->attribute_value_len > 0){
358                 // get ready for attribute value
359                 connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_VALUE;
360                 return;
361             }
362 
363             // emit empty attribute
364             attribute_id = big_endian_read_32(connection->parser_attribute_header, 0);
365             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);
366 
367             // done, see below
368             break;
369 
370         case AVRCP_PARSER_GET_ATTRIBUTE_VALUE:
371             connection->attribute_value[connection->attribute_value_offset++] = byte;
372             connection->list_offset++;
373 
374             if (connection->attribute_value_offset < connection->attribute_value_len) return;
375 
376             // emit (potentially partial) attribute
377             attribute_id = big_endian_read_32(connection->parser_attribute_header, 0);
378             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);
379 
380             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
381             if (connection->attribute_value_offset < attribute_total_value_len){
382                 // ignore rest of attribute
383                 connection->parser_state = AVRCP_PARSER_IGNORE_REST_OF_ATTRIBUTE_VALUE;
384                 return;
385             }
386 
387             // done, see below
388             break;
389 
390         case AVRCP_PARSER_IGNORE_REST_OF_ATTRIBUTE_VALUE:
391             connection->attribute_value_offset++;
392             connection->list_offset++;
393 
394             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
395             if (connection->attribute_value_offset < attribute_total_value_len) return;
396 
397             // done, see below
398             break;
399 
400         default:
401             return;
402     }
403 
404     // attribute fully read, check if more to come
405     if (connection->list_offset < connection->list_size){
406         // more to come, reset parser
407         connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_HEADER;
408         connection->parser_attribute_header_pos = 0;
409         connection->attribute_value_offset = 0;
410     } else {
411         // fully done
412         avrcp_parser_reset(connection);
413         avrcp_controller_emit_now_playing_info_event_done(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, 0);
414     }
415 }
416 
417 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){
418     int i;
419     for (i=0;i<num_bytes_to_read;i++){
420         avrcp_parser_process_byte(packet[i], connection, ctype);
421     }
422 }
423 
424 
425 static int avrcp_send_cmd(avrcp_connection_t * connection, avrcp_packet_type_t packet_type){
426     uint8_t command[AVRCP_CMD_BUFFER_SIZE];
427     int pos = 0;
428 
429     // non-fragmented: transport header (1) + PID (2)
430     // fragmented:     transport header (1) + num packets (1) + PID (2)
431 
432     // transport header : transaction label | Packet_type | C/R | IPID (1 == invalid profile identifier)
433     command[pos++] = (connection->transaction_label << 4) | (packet_type << 2) | (AVRCP_COMMAND_FRAME << 1) | 0;
434 
435     if (packet_type == AVRCP_START_PACKET){
436         // num packets: (3 bytes overhead (PID, num packets) + command) / (MTU - transport header).
437         // to get number of packets using integer division, we subtract 1 from the data e.g. len = 5, packet size 5 => need 1 packet
438         command[pos++] = ((connection->cmd_operands_fragmented_len + 3 - 1) / (AVRCP_CMD_BUFFER_SIZE - 1)) + 1;
439     }
440 
441     if ((packet_type == AVRCP_SINGLE_PACKET) || (packet_type == AVRCP_START_PACKET)){
442         // Profile IDentifier (PID)
443         command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL >> 8;
444         command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL & 0x00FF;
445 
446         // command_type
447         command[pos++] = connection->command_type;
448         // subunit_type | subunit ID
449         command[pos++] = (connection->subunit_type << 3) | connection->subunit_id;
450         // opcode
451         command[pos++] = (uint8_t)connection->command_opcode;
452     }
453 
454     if (packet_type == AVRCP_SINGLE_PACKET){
455         // operands
456         (void)memcpy(command + pos, connection->cmd_operands,
457                      connection->cmd_operands_length);
458         pos += connection->cmd_operands_length;
459     } else {
460         uint16_t bytes_free = AVRCP_CMD_BUFFER_SIZE - pos;
461         uint16_t bytes_to_store = connection->cmd_operands_fragmented_len-connection->cmd_operands_fragmented_pos;
462         uint16_t bytes_to_copy = btstack_min(bytes_to_store, bytes_free);
463         (void)memcpy(command + pos,
464                      &connection->cmd_operands_fragmented_buffer[connection->cmd_operands_fragmented_pos],
465                      bytes_to_copy);
466         pos += bytes_to_copy;
467         connection->cmd_operands_fragmented_pos += bytes_to_copy;
468     }
469 
470     return l2cap_send(connection->l2cap_signaling_cid, command, pos);
471 }
472 
473 static void avrcp_press_and_hold_timeout_handler(btstack_timer_source_t * timer){
474     UNUSED(timer);
475     avrcp_connection_t * connection = (avrcp_connection_t*) btstack_run_loop_get_timer_context(timer);
476     btstack_run_loop_set_timer(&connection->press_and_hold_cmd_timer, 2000); // 2 seconds timeout
477     btstack_run_loop_add_timer(&connection->press_and_hold_cmd_timer);
478     connection->state = AVCTP_W2_SEND_PRESS_COMMAND;
479     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
480 }
481 
482 static void avrcp_press_and_hold_timer_start(avrcp_connection_t * connection){
483     btstack_run_loop_remove_timer(&connection->press_and_hold_cmd_timer);
484     btstack_run_loop_set_timer_handler(&connection->press_and_hold_cmd_timer, avrcp_press_and_hold_timeout_handler);
485     btstack_run_loop_set_timer_context(&connection->press_and_hold_cmd_timer, connection);
486     btstack_run_loop_set_timer(&connection->press_and_hold_cmd_timer, 2000); // 2 seconds timeout
487     btstack_run_loop_add_timer(&connection->press_and_hold_cmd_timer);
488 }
489 
490 static void avrcp_press_and_hold_timer_stop(avrcp_connection_t * connection){
491     connection->continuous_fast_forward_cmd = 0;
492     btstack_run_loop_remove_timer(&connection->press_and_hold_cmd_timer);
493 }
494 
495 
496 static uint8_t avrcp_controller_request_pass_through_release_control_cmd(avrcp_connection_t * connection){
497     connection->state = AVCTP_W2_SEND_RELEASE_COMMAND;
498     if (connection->continuous_fast_forward_cmd){
499         avrcp_press_and_hold_timer_stop(connection);
500     }
501     connection->cmd_operands[0] = 0x80 | connection->cmd_operands[0];
502     connection->transaction_label++;
503     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
504     return ERROR_CODE_SUCCESS;
505 }
506 
507 static inline uint8_t avrcp_controller_request_pass_through_press_control_cmd(uint16_t avrcp_cid, avrcp_operation_id_t opid, uint16_t playback_speed, uint8_t continuous_fast_forward_cmd){
508     log_info("Send command %d", opid);
509     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
510     if (!connection){
511         log_error("Could not find a connection. avrcp cid 0x%02x", avrcp_cid);
512         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
513     }
514 
515     if (connection->state != AVCTP_CONNECTION_OPENED){
516         log_error("Connection in wrong state %d, expected %d. avrcp cid 0x%02x", connection->state, AVCTP_CONNECTION_OPENED, avrcp_cid);
517         return ERROR_CODE_COMMAND_DISALLOWED;
518     }
519     connection->state = AVCTP_W2_SEND_PRESS_COMMAND;
520     connection->command_opcode =  AVRCP_CMD_OPCODE_PASS_THROUGH;
521     connection->command_type = AVRCP_CTYPE_CONTROL;
522     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
523     connection->subunit_id =   AVRCP_SUBUNIT_ID;
524     connection->cmd_operands_length = 0;
525 
526     connection->continuous_fast_forward_cmd = continuous_fast_forward_cmd;
527     connection->cmd_operands_length = 2;
528     connection->cmd_operands[0] = opid;
529     if (playback_speed > 0){
530         connection->cmd_operands[2] = playback_speed;
531         connection->cmd_operands_length++;
532     }
533     connection->cmd_operands[1] = connection->cmd_operands_length - 2;
534 
535     if (connection->continuous_fast_forward_cmd){
536         avrcp_press_and_hold_timer_start(connection);
537     }
538 
539     connection->transaction_label++;
540     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
541     return ERROR_CODE_SUCCESS;
542 }
543 
544 static uint8_t request_single_pass_through_press_control_cmd(uint16_t avrcp_cid, avrcp_operation_id_t opid, uint16_t playback_speed){
545     return avrcp_controller_request_pass_through_press_control_cmd(avrcp_cid, opid, playback_speed, 0);
546 }
547 
548 static uint8_t request_continuous_pass_through_press_control_cmd(uint16_t avrcp_cid, avrcp_operation_id_t opid, uint16_t playback_speed){
549     return avrcp_controller_request_pass_through_press_control_cmd(avrcp_cid, opid, playback_speed, 1);
550 }
551 
552 static int avrcp_controller_register_notification(avrcp_connection_t * connection, avrcp_notification_event_id_t event_id){
553     if (connection->notifications_to_deregister & (1 << event_id)) return 0;
554     if (connection->notifications_enabled & (1 << event_id)) return 0;
555     if (connection->notifications_to_register & (1 << event_id)) return 0;
556     connection->notifications_to_register |= (1 << event_id);
557     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
558     return 1;
559 }
560 
561 static void avrcp_controller_prepare_notification(avrcp_connection_t * connection, avrcp_notification_event_id_t event_id){
562     connection->transaction_label++;
563     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
564     connection->command_type = AVRCP_CTYPE_NOTIFY;
565     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
566     connection->subunit_id = AVRCP_SUBUNIT_ID;
567     int pos = 0;
568     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
569     pos += 3;
570     connection->cmd_operands[pos++] = AVRCP_PDU_ID_REGISTER_NOTIFICATION;
571     connection->cmd_operands[pos++] = 0;                     // reserved(upper 6) | packet_type -> 0
572     big_endian_store_16(connection->cmd_operands, pos, 5);     // parameter length
573     pos += 2;
574     connection->cmd_operands[pos++] = event_id;
575     big_endian_store_32(connection->cmd_operands, pos, 1); // send notification on playback position every second, for other notifications it is ignored
576     pos += 4;
577     connection->cmd_operands_length = pos;
578     // AVRCP_SPEC_V14.pdf 166
579     // answer page 61
580 }
581 
582 static uint8_t avrcp_controller_request_abort_continuation(avrcp_connection_t * connection){
583     connection->state = AVCTP_W2_SEND_COMMAND;
584     connection->transaction_label++;
585     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
586     connection->command_type = AVRCP_CTYPE_CONTROL;
587     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
588     connection->subunit_id = AVRCP_SUBUNIT_ID;
589     int pos = 0;
590     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
591     pos += 3;
592     connection->cmd_operands[pos++] = AVRCP_PDU_ID_REQUEST_ABORT_CONTINUING_RESPONSE; // PDU ID
593     connection->cmd_operands[pos++] = 0;
594     // Parameter Length
595     connection->cmd_operands_length = 8;
596     big_endian_store_16(connection->cmd_operands, pos, 1);
597     pos += 2;
598     connection->cmd_operands[pos++] = AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES;
599     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
600     return ERROR_CODE_SUCCESS;
601 }
602 
603 
604 static uint8_t avrcp_controller_request_continue_response(avrcp_connection_t * connection){
605     connection->state = AVCTP_W2_SEND_COMMAND;
606     connection->transaction_label++;
607     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
608     connection->command_type = AVRCP_CTYPE_CONTROL;
609     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
610     connection->subunit_id = AVRCP_SUBUNIT_ID;
611     int pos = 0;
612     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
613     pos += 3;
614     connection->cmd_operands[pos++] = AVRCP_PDU_ID_REQUEST_CONTINUING_RESPONSE; // PDU ID
615     connection->cmd_operands[pos++] = 0;
616     // Parameter Length
617     connection->cmd_operands_length = 8;
618     big_endian_store_16(connection->cmd_operands, pos, 1);
619     pos += 2;
620     connection->cmd_operands[pos++] = AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES;
621     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
622     return ERROR_CODE_SUCCESS;
623 }
624 
625 static void avrcp_handle_l2cap_data_packet_for_signaling_connection(avrcp_connection_t * connection, uint8_t *packet, uint16_t size){
626     if (size < 6u) return;
627 
628     uint16_t pos = 3;
629     uint8_t  pdu_id;
630 
631     avrcp_frame_type_t  frame_type = (avrcp_frame_type_t)((packet[0] >> 1) & 0x01);
632     if (frame_type != AVRCP_RESPONSE_FRAME) return;
633 
634     avrcp_packet_type_t packet_type = (avrcp_packet_type_t)((packet[0] >> 2) & 0x03);
635     switch (packet_type){
636         case AVRCP_SINGLE_PACKET:
637             break;
638         default:
639             log_info("Fragmentation is not supported");
640             return;
641     }
642 
643     avrcp_command_type_t ctype = (avrcp_command_type_t) packet[pos++];
644 
645     uint8_t byte_value = packet[pos++];
646     avrcp_subunit_type_t subunit_type = (avrcp_subunit_type_t) (byte_value >> 3);
647     avrcp_subunit_type_t subunit_id   = (avrcp_subunit_type_t)   (byte_value & 0x07);
648     uint8_t opcode = packet[pos++];
649 
650     uint16_t param_length;
651 
652     switch (opcode){
653         case AVRCP_CMD_OPCODE_SUBUNIT_INFO:{
654             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE) return;
655             connection->state = AVCTP_CONNECTION_OPENED;
656             // page, extention code (1)
657             pos++;
658             uint8_t unit_type = packet[pos] >> 3;
659             uint8_t max_subunit_ID = packet[pos] & 0x07;
660             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);
661             break;
662         }
663         case AVRCP_CMD_OPCODE_UNIT_INFO:{
664             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE) return;
665             connection->state = AVCTP_CONNECTION_OPENED;
666             // byte value 7 (1)
667             pos++;
668             uint8_t unit_type = packet[pos] >> 3;
669             uint8_t unit = packet[pos] & 0x07;
670             pos++;
671             uint32_t company_id = big_endian_read_24(packet, pos);
672             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,
673                 ctype, subunit_type, subunit_id, opcode, unit_type, unit, company_id);
674             break;
675         }
676         case AVRCP_CMD_OPCODE_VENDOR_DEPENDENT:
677             // Company ID (3)
678             pos += 3;
679             pdu_id = packet[pos++];
680             // packet type (1)
681             pos++;
682             param_length = big_endian_read_16(packet, pos);
683             pos += 2;
684             log_info("operands length %d, remaining size %d", param_length, size - pos);
685 
686             if ((size - pos) < param_length) {
687                 printf_hexdump(packet, size);
688                 log_error("Wrong packet size %d < %d", size - pos, param_length);
689                 return;
690             };
691 
692             if ((connection->state != AVCTP_W2_RECEIVE_RESPONSE) && (pdu_id != AVRCP_PDU_ID_REGISTER_NOTIFICATION)){
693                 log_info("AVRCP_CMD_OPCODE_VENDOR_DEPENDENT state %d", connection->state);
694                 return;
695             }
696             connection->state = AVCTP_CONNECTION_OPENED;
697 
698             log_info("VENDOR DEPENDENT response: pdu id 0x%02x, param_length %d, status %s", pdu_id, param_length, avrcp_ctype2str(ctype));
699             switch (pdu_id){
700                 case AVRCP_PDU_ID_REGISTER_NOTIFICATION:{
701                     avrcp_notification_event_id_t event_id = (avrcp_notification_event_id_t) packet[pos++];
702                     uint16_t event_mask = (1 << event_id);
703                     uint16_t reset_event_mask = ~event_mask;
704                     switch (ctype){
705                         case AVRCP_CTYPE_RESPONSE_INTERIM:
706                             // register as enabled
707                             connection->notifications_enabled |= event_mask;
708                             break;
709                         case AVRCP_CTYPE_RESPONSE_CHANGED_STABLE:
710                             // received change, event is considered deregistered
711                             // we are re-enabling it automatically, if it is not
712                             // explicitly disabled
713                             connection->notifications_enabled &= reset_event_mask;
714                             if (! (connection->notifications_to_deregister & event_mask)){
715                                 avrcp_controller_register_notification(connection, event_id);
716                             } else {
717                                 connection->notifications_to_deregister &= reset_event_mask;
718                             }
719                             break;
720                         default:
721                             connection->notifications_to_register &= reset_event_mask;
722                             connection->notifications_enabled &= reset_event_mask;
723                             connection->notifications_to_deregister &= reset_event_mask;
724                             break;
725                     }
726 
727                     avrcp_controller_emit_notification_for_event_id(connection->avrcp_cid, event_id, ctype, packet+pos);
728                     break;
729                 }
730 
731                 case AVRCP_PDU_ID_GET_CURRENT_PLAYER_APPLICATION_SETTING_VALUE:{
732                     uint8_t num_attributes = packet[pos++];
733                     int i;
734                     avrcp_repeat_mode_t  repeat_mode =  AVRCP_REPEAT_MODE_INVALID;
735                     avrcp_shuffle_mode_t shuffle_mode = AVRCP_SHUFFLE_MODE_INVALID;
736                     for (i = 0; i < num_attributes; i++){
737                         uint8_t attribute_id    = packet[pos++];
738                         uint8_t value = packet[pos++];
739                         switch (attribute_id){
740                             case 0x02:
741                                 repeat_mode = (avrcp_repeat_mode_t) value;
742                                 break;
743                             case 0x03:
744                                 shuffle_mode = (avrcp_shuffle_mode_t) value;
745                                 break;
746                             default:
747                                 break;
748                         }
749                     }
750                     avrcp_controller_emit_repeat_and_shuffle_mode(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, repeat_mode, shuffle_mode);
751                     break;
752                 }
753 
754                 case AVRCP_PDU_ID_SET_PLAYER_APPLICATION_SETTING_VALUE:{
755                     uint16_t offset = 0;
756                     uint8_t event[6];
757                     event[offset++] = HCI_EVENT_AVRCP_META;
758                     event[offset++] = sizeof(event) - 2;
759                     event[offset++] = AVRCP_SUBEVENT_PLAYER_APPLICATION_VALUE_RESPONSE;
760                     little_endian_store_16(event, offset, connection->avrcp_cid);
761                     offset += 2;
762                     event[offset++] = ctype;
763                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
764                     break;
765                 }
766 
767                 case AVRCP_PDU_ID_SET_ABSOLUTE_VOLUME:{
768                     uint16_t offset = 0;
769                     uint8_t event[7];
770                     event[offset++] = HCI_EVENT_AVRCP_META;
771                     event[offset++] = sizeof(event) - 2;
772                     event[offset++] = AVRCP_SUBEVENT_SET_ABSOLUTE_VOLUME_RESPONSE;
773                     little_endian_store_16(event, offset, connection->avrcp_cid);
774                     offset += 2;
775                     event[offset++] = ctype;
776                     event[offset++] = packet[pos++];
777                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
778                     break;
779                 }
780 
781                 case AVRCP_PDU_ID_GET_CAPABILITIES:{
782                     avrcp_capability_id_t capability_id = (avrcp_capability_id_t) packet[pos++];
783                     uint8_t capability_count = packet[pos++];
784                     uint16_t i;
785                     uint16_t offset = 0;
786                     uint8_t event[10];
787 
788                     switch (capability_id){
789 
790                         case AVRCP_CAPABILITY_ID_COMPANY:
791                             for (i = 0; i < capability_count; i++){
792                                 uint32_t company_id = big_endian_read_24(packet, pos);
793                                 pos += 3;
794                                 log_info("  0x%06" PRIx32 ", ", company_id);
795 
796                                 offset = 0;
797                                 event[offset++] = HCI_EVENT_AVRCP_META;
798                                 event[offset++] = sizeof(event) - 2;
799                                 event[offset++] = AVRCP_SUBEVENT_GET_CAPABILITY_COMPANY_ID;
800                                 little_endian_store_16(event, offset, connection->avrcp_cid);
801                                 offset += 2;
802                                 event[offset++] = ctype;
803                                 event[offset++] = 0;
804                                 little_endian_store_24(event, offset, company_id);
805                                 offset += 3;
806                                 (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, offset);
807                                 break;
808                             }
809 
810                             offset = 0;
811                             event[offset++] = HCI_EVENT_AVRCP_META;
812                             event[offset++] = sizeof(event) - 2;
813                             event[offset++] = AVRCP_SUBEVENT_GET_CAPABILITY_COMPANY_ID_DONE;
814                             little_endian_store_16(event, offset, connection->avrcp_cid);
815                             offset += 2;
816                             event[offset++] = ctype;
817                             event[offset++] = 0;
818                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, offset);
819                             break;
820 
821                         case AVRCP_CAPABILITY_ID_EVENT:
822                             for (i = 0; i < capability_count; i++){
823                                 uint8_t event_id = packet[pos++];
824                                 log_info("  0x%02x %s", event_id, avrcp_event2str(event_id));
825 
826                                 offset = 0;
827                                 event[offset++] = HCI_EVENT_AVRCP_META;
828                                 event[offset++] = sizeof(event) - 2;
829                                 event[offset++] = AVRCP_SUBEVENT_GET_CAPABILITY_EVENT_ID;
830                                 little_endian_store_16(event, offset, connection->avrcp_cid);
831                                 offset += 2;
832                                 event[offset++] = ctype;
833                                 event[offset++] = 0;
834                                 event[offset++] = event_id;
835                                 (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, offset);
836                             }
837 
838                             offset = 0;
839                             event[offset++] = HCI_EVENT_AVRCP_META;
840                             event[offset++] = sizeof(event) - 2;
841                             event[offset++] = AVRCP_SUBEVENT_GET_CAPABILITY_EVENT_ID_DONE;
842                             little_endian_store_16(event, offset, connection->avrcp_cid);
843                             offset += 2;
844                             event[offset++] = ctype;
845                             event[offset++] = 0;
846                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
847                             break;
848                     }
849                     break;
850                 }
851 
852                 case AVRCP_PDU_ID_GET_PLAY_STATUS:{
853                     uint32_t song_length = big_endian_read_32(packet, pos);
854                     pos += 4;
855                     uint32_t song_position = big_endian_read_32(packet, pos);
856                     pos += 4;
857                     uint8_t play_status = packet[pos];
858 
859                     uint8_t event[15];
860                     int offset = 0;
861                     event[offset++] = HCI_EVENT_AVRCP_META;
862                     event[offset++] = sizeof(event) - 2;
863                     event[offset++] = AVRCP_SUBEVENT_PLAY_STATUS;
864                     little_endian_store_16(event, offset, connection->avrcp_cid);
865                     offset += 2;
866                     event[offset++] = ctype;
867                     little_endian_store_32(event, offset, song_length);
868                     offset += 4;
869                     little_endian_store_32(event, offset, song_position);
870                     offset += 4;
871                     event[offset++] = play_status;
872                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
873                     break;
874                 }
875 
876                 case AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES:{
877                     switch (packet_type){
878                         case AVRCP_START_PACKET:
879                         case AVRCP_SINGLE_PACKET:
880                             avrcp_parser_reset(connection);
881                             connection->list_size = param_length;
882                             connection->num_attributes = packet[pos++];
883 
884                             avrcp_controller_parse_and_emit_element_attrs(packet+pos, size-pos, connection, ctype);
885 
886                             if (packet_type == AVRCP_START_PACKET){
887                                 avrcp_controller_request_continue_response(connection);
888                             }
889                             break;
890                         case AVRCP_CONTINUE_PACKET:
891                         case AVRCP_END_PACKET:
892                             connection->num_received_fragments++;
893                             if (connection->num_received_fragments < connection->max_num_fragments){
894                                 avrcp_controller_parse_and_emit_element_attrs(packet+pos, size-pos, connection, ctype);
895                                 if (packet_type == AVRCP_CONTINUE_PACKET){
896                                     avrcp_controller_request_continue_response(connection);
897                                 }
898                             } else {
899                                 avrcp_controller_request_abort_continuation(connection);
900                                 avrcp_controller_emit_now_playing_info_event_done(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, 1);
901                                 avrcp_parser_reset(connection);
902                             }
903                             break;
904                     }
905                 }
906                 default:
907                     break;
908             }
909             break;
910         case AVRCP_CMD_OPCODE_PASS_THROUGH:{
911             uint8_t operation_id = packet[pos++];
912             switch (connection->state){
913                 case AVCTP_W2_RECEIVE_PRESS_RESPONSE:
914                     if (connection->continuous_fast_forward_cmd){
915                         connection->state = AVCTP_W4_STOP;
916                     } else {
917                         connection->state = AVCTP_W2_SEND_RELEASE_COMMAND;
918                     }
919                     break;
920                 case AVCTP_W2_RECEIVE_RESPONSE:
921                     connection->state = AVCTP_CONNECTION_OPENED;
922                     break;
923                 default:
924                     break;
925             }
926             if (connection->state == AVCTP_W4_STOP){
927                 avrcp_controller_emit_operation_status(avrcp_controller_context.avrcp_callback, AVRCP_SUBEVENT_OPERATION_START, connection->avrcp_cid, ctype, operation_id);
928             }
929             if (connection->state == AVCTP_CONNECTION_OPENED) {
930                 // RELEASE response
931                 operation_id = operation_id & 0x7F;
932                 avrcp_controller_emit_operation_status(avrcp_controller_context.avrcp_callback, AVRCP_SUBEVENT_OPERATION_COMPLETE, connection->avrcp_cid, ctype, operation_id);
933             }
934             if (connection->state == AVCTP_W2_SEND_RELEASE_COMMAND){
935                 // PRESS response
936                 avrcp_controller_request_pass_through_release_control_cmd(connection);
937             }
938             break;
939         }
940         default:
941             break;
942     }
943 
944     // trigger pending notification reqistrations
945     if ((connection->state == AVCTP_CONNECTION_OPENED) && connection->notifications_to_register){
946         avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
947     }
948 }
949 
950 static void avrcp_controller_handle_can_send_now(avrcp_connection_t * connection){
951     int i;
952     switch (connection->state){
953         case AVCTP_W2_SEND_PRESS_COMMAND:
954             connection->state = AVCTP_W2_RECEIVE_PRESS_RESPONSE;
955             avrcp_send_cmd(connection, AVRCP_SINGLE_PACKET);
956             return;
957         case AVCTP_W2_SEND_COMMAND:
958         case AVCTP_W2_SEND_RELEASE_COMMAND:
959             connection->state = AVCTP_W2_RECEIVE_RESPONSE;
960             avrcp_send_cmd(connection, AVRCP_SINGLE_PACKET);
961             return;
962         case AVCTP_W2_SEND_FRAGMENTED_COMMAND:
963             if (connection->cmd_operands_fragmented_pos == 0){
964                  avrcp_send_cmd(connection, AVRCP_START_PACKET);
965                  avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
966             } else {
967                 if ((connection->cmd_operands_fragmented_len - connection->cmd_operands_fragmented_pos) > avrcp_get_max_payload_size_for_packet_type(AVRCP_CONTINUE_PACKET)){
968                      avrcp_send_cmd(connection, AVRCP_CONTINUE_PACKET);
969                      avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
970                  } else {
971                     connection->state = AVCTP_W2_RECEIVE_RESPONSE;
972                     avrcp_send_cmd(connection, AVRCP_END_PACKET);
973                  }
974             }
975             return;
976         default:
977             break;
978     }
979     // send register notification if queued
980     if (connection->notifications_to_register != 0){
981         for (i = 1; i <= AVRCP_NOTIFICATION_EVENT_VOLUME_CHANGED; i++){
982             if (connection->notifications_to_register & (1<<i)){
983                 connection->notifications_to_register &= ~ (1 << i);
984                 avrcp_controller_prepare_notification(connection, (avrcp_notification_event_id_t) i);
985                 connection->state = AVCTP_W2_RECEIVE_RESPONSE;
986                 avrcp_send_cmd(connection, AVRCP_SINGLE_PACKET);
987                 return;
988             }
989         }
990     }
991 }
992 
993 static void avrcp_controller_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
994     avrcp_connection_t * connection;
995 
996     switch (packet_type) {
997         case L2CAP_DATA_PACKET:
998             connection = avrcp_get_connection_for_l2cap_signaling_cid_for_role(AVRCP_CONTROLLER, channel);
999             avrcp_handle_l2cap_data_packet_for_signaling_connection(connection, packet, size);
1000             break;
1001 
1002         case HCI_EVENT_PACKET:
1003             switch (hci_event_packet_get_type(packet)){
1004                 case L2CAP_EVENT_CAN_SEND_NOW:
1005                     connection = avrcp_get_connection_for_l2cap_signaling_cid_for_role(AVRCP_CONTROLLER, channel);
1006                     avrcp_controller_handle_can_send_now(connection);
1007                     break;
1008             default:
1009                 break;
1010         }
1011         default:
1012             break;
1013     }
1014 }
1015 
1016 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){
1017     avrcp_create_sdp_record(1, service, service_record_handle, avrcp_controller_supports_browsing(supported_features), supported_features, service_name, service_provider_name);
1018 }
1019 
1020 void avrcp_controller_init(void){
1021     avrcp_controller_context.role = AVRCP_CONTROLLER;
1022     avrcp_controller_context.packet_handler = avrcp_controller_packet_handler;
1023     avrcp_register_controller_packet_handler(&avrcp_controller_packet_handler);
1024 }
1025 
1026 void avrcp_controller_register_packet_handler(btstack_packet_handler_t callback){
1027     btstack_assert(callback != NULL);
1028     avrcp_controller_context.avrcp_callback = callback;
1029 }
1030 
1031 
1032 uint8_t avrcp_controller_play(uint16_t avrcp_cid){
1033     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PLAY, 0);
1034 }
1035 
1036 uint8_t avrcp_controller_stop(uint16_t avrcp_cid){
1037     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_STOP, 0);
1038 }
1039 
1040 uint8_t avrcp_controller_pause(uint16_t avrcp_cid){
1041     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PAUSE, 0);
1042 }
1043 
1044 uint8_t avrcp_controller_forward(uint16_t avrcp_cid){
1045     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FORWARD, 0);
1046 }
1047 
1048 uint8_t avrcp_controller_backward(uint16_t avrcp_cid){
1049     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_BACKWARD, 0);
1050 }
1051 
1052 uint8_t avrcp_controller_volume_up(uint16_t avrcp_cid){
1053     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_UP, 0);
1054 }
1055 
1056 uint8_t avrcp_controller_volume_down(uint16_t avrcp_cid){
1057     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_DOWN, 0);
1058 }
1059 
1060 uint8_t avrcp_controller_mute(uint16_t avrcp_cid){
1061     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_MUTE, 0);
1062 }
1063 
1064 uint8_t avrcp_controller_skip(uint16_t avrcp_cid){
1065     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_SKIP, 0);
1066 }
1067 
1068 uint8_t avrcp_controller_fast_forward(uint16_t avrcp_cid){
1069     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FAST_FORWARD, 0);
1070 }
1071 
1072 uint8_t avrcp_controller_rewind(uint16_t avrcp_cid){
1073     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_REWIND, 0);
1074 }
1075 
1076 /* start continuous cmds */
1077 
1078 uint8_t avrcp_controller_press_and_hold_play(uint16_t avrcp_cid){
1079     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PLAY, 0);
1080 }
1081 uint8_t avrcp_controller_press_and_hold_stop(uint16_t avrcp_cid){
1082     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_STOP, 0);
1083 }
1084 uint8_t avrcp_controller_press_and_hold_pause(uint16_t avrcp_cid){
1085     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PAUSE, 0);
1086 }
1087 uint8_t avrcp_controller_press_and_hold_forward(uint16_t avrcp_cid){
1088     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FORWARD, 0);
1089 }
1090 uint8_t avrcp_controller_press_and_hold_backward(uint16_t avrcp_cid){
1091     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_BACKWARD, 0);
1092 }
1093 uint8_t avrcp_controller_press_and_hold_fast_forward(uint16_t avrcp_cid){
1094     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FAST_FORWARD, 0);
1095 }
1096 uint8_t avrcp_controller_press_and_hold_rewind(uint16_t avrcp_cid){
1097     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_REWIND, 0);
1098 }
1099 uint8_t avrcp_controller_press_and_hold_volume_up(uint16_t avrcp_cid){
1100     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_UP, 0);
1101 }
1102 uint8_t avrcp_controller_press_and_hold_volume_down(uint16_t avrcp_cid){
1103     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_DOWN, 0);
1104 }
1105 uint8_t avrcp_controller_press_and_hold_mute(uint16_t avrcp_cid){
1106     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_MUTE, 0);
1107 }
1108 
1109 /* stop continuous cmds */
1110 uint8_t avrcp_controller_release_press_and_hold_cmd(uint16_t avrcp_cid){
1111     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1112     if (!connection){
1113         log_error("avrcp_stop_play: could not find a connection.");
1114         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1115     }
1116     if (connection->state != AVCTP_W4_STOP) return ERROR_CODE_COMMAND_DISALLOWED;
1117     return avrcp_controller_request_pass_through_release_control_cmd(connection);
1118 }
1119 
1120 uint8_t avrcp_controller_enable_notification(uint16_t avrcp_cid, avrcp_notification_event_id_t event_id){
1121     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1122     if (!connection){
1123         log_error("avrcp_get_play_status: could not find a connection.");
1124         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1125     }
1126     avrcp_controller_register_notification(connection, event_id);
1127     return ERROR_CODE_SUCCESS;
1128 }
1129 
1130 uint8_t avrcp_controller_disable_notification(uint16_t avrcp_cid, avrcp_notification_event_id_t event_id){
1131     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1132     if (!connection){
1133         log_error("avrcp_get_play_status: could not find a connection.");
1134         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1135     }
1136     connection->notifications_to_deregister |= (1 << event_id);
1137     return ERROR_CODE_SUCCESS;
1138 }
1139 
1140 uint8_t avrcp_controller_unit_info(uint16_t avrcp_cid){
1141     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1142     if (!connection){
1143         log_error("avrcp_unit_info: could not find a connection.");
1144         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1145     }
1146     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1147     connection->state = AVCTP_W2_SEND_COMMAND;
1148 
1149     connection->transaction_label++;
1150     connection->command_opcode = AVRCP_CMD_OPCODE_UNIT_INFO;
1151     connection->command_type = AVRCP_CTYPE_STATUS;
1152     connection->subunit_type = AVRCP_SUBUNIT_TYPE_UNIT; //vendor unique
1153     connection->subunit_id =   AVRCP_SUBUNIT_ID_IGNORE;
1154     memset(connection->cmd_operands, 0xFF, connection->cmd_operands_length);
1155     connection->cmd_operands_length = 5;
1156     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1157     return ERROR_CODE_SUCCESS;
1158 }
1159 
1160 uint8_t avrcp_controller_subunit_info(uint16_t avrcp_cid){
1161     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1162     if (!connection){
1163         log_error("avrcp_unit_info: could not find a connection.");
1164         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1165     }
1166     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1167     connection->state = AVCTP_W2_SEND_COMMAND;
1168 
1169     connection->transaction_label++;
1170     connection->command_opcode = AVRCP_CMD_OPCODE_SUBUNIT_INFO;
1171     connection->command_type = AVRCP_CTYPE_STATUS;
1172     connection->subunit_type = AVRCP_SUBUNIT_TYPE_UNIT; //vendor unique
1173     connection->subunit_id =   AVRCP_SUBUNIT_ID_IGNORE;
1174     memset(connection->cmd_operands, 0xFF, connection->cmd_operands_length);
1175     connection->cmd_operands[0] = 7; // page: 0, extention_code: 7
1176     connection->cmd_operands_length = 5;
1177     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1178     return ERROR_CODE_SUCCESS;
1179 }
1180 
1181 static uint8_t avrcp_controller_get_capabilities(uint16_t avrcp_cid, uint8_t capability_id){
1182     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1183     if (!connection){
1184         log_error("avrcp_get_capabilities: could not find a connection.");
1185         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1186     }
1187     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1188     connection->state = AVCTP_W2_SEND_COMMAND;
1189 
1190     connection->transaction_label++;
1191     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1192     connection->command_type = AVRCP_CTYPE_STATUS;
1193     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1194     connection->subunit_id = AVRCP_SUBUNIT_ID;
1195     big_endian_store_24(connection->cmd_operands, 0, BT_SIG_COMPANY_ID);
1196     connection->cmd_operands[3] = AVRCP_PDU_ID_GET_CAPABILITIES; // PDU ID
1197     connection->cmd_operands[4] = 0;
1198     big_endian_store_16(connection->cmd_operands, 5, 1); // parameter length
1199     connection->cmd_operands[7] = capability_id;                  // capability ID
1200     connection->cmd_operands_length = 8;
1201     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1202     return ERROR_CODE_SUCCESS;
1203 }
1204 
1205 uint8_t avrcp_controller_get_supported_company_ids(uint16_t avrcp_cid){
1206     return avrcp_controller_get_capabilities(avrcp_cid, AVRCP_CAPABILITY_ID_COMPANY);
1207 }
1208 
1209 uint8_t avrcp_controller_get_supported_events(uint16_t avrcp_cid){
1210     return avrcp_controller_get_capabilities(avrcp_cid, AVRCP_CAPABILITY_ID_EVENT);
1211 }
1212 
1213 uint8_t avrcp_controller_get_play_status(uint16_t avrcp_cid){
1214     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1215     if (!connection){
1216         log_error("avrcp_get_play_status: could not find a connection.");
1217         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1218     }
1219     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1220     connection->state = AVCTP_W2_SEND_COMMAND;
1221     connection->transaction_label++;
1222     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1223     connection->command_type = AVRCP_CTYPE_STATUS;
1224     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1225     connection->subunit_id = AVRCP_SUBUNIT_ID;
1226     big_endian_store_24(connection->cmd_operands, 0, BT_SIG_COMPANY_ID);
1227     connection->cmd_operands[3] = AVRCP_PDU_ID_GET_PLAY_STATUS;
1228     connection->cmd_operands[4] = 0;                     // reserved(upper 6) | packet_type -> 0
1229     big_endian_store_16(connection->cmd_operands, 5, 0); // parameter length
1230     connection->cmd_operands_length = 7;
1231     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1232     return ERROR_CODE_SUCCESS;
1233 }
1234 
1235 uint8_t avrcp_controller_set_addressed_player(uint16_t avrcp_cid, uint16_t addressed_player_id){
1236     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1237     if (!connection){
1238         log_error("avrcp_get_capabilities: could not find a connection.");
1239         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1240     }
1241     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1242     connection->state = AVCTP_W2_SEND_COMMAND;
1243 
1244     connection->transaction_label++;
1245     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1246     connection->command_type = AVRCP_CTYPE_CONTROL;
1247     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1248     connection->subunit_id = AVRCP_SUBUNIT_ID;
1249     int pos = 0;
1250     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1251     pos += 3;
1252     connection->cmd_operands[pos++] = AVRCP_PDU_ID_SET_ADDRESSED_PLAYER; // PDU ID
1253     connection->cmd_operands[pos++] = 0;
1254 
1255     // Parameter Length
1256     big_endian_store_16(connection->cmd_operands, pos, 2);
1257     pos += 2;
1258 
1259     big_endian_store_16(connection->cmd_operands, pos, addressed_player_id);
1260     pos += 2;
1261 
1262     connection->cmd_operands_length = pos;
1263     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1264     return ERROR_CODE_SUCCESS;
1265 }
1266 
1267 uint8_t avrcp_controller_get_now_playing_info(uint16_t avrcp_cid){
1268     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1269     if (!connection){
1270         log_error("avrcp_get_capabilities: could not find a connection.");
1271         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1272     }
1273     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1274     connection->state = AVCTP_W2_SEND_COMMAND;
1275 
1276     connection->transaction_label++;
1277     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1278     connection->command_type = AVRCP_CTYPE_STATUS;
1279     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1280     connection->subunit_id = AVRCP_SUBUNIT_ID;
1281     int pos = 0;
1282     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1283     pos += 3;
1284     connection->cmd_operands[pos++] = AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES; // PDU ID
1285     connection->cmd_operands[pos++] = 0;
1286 
1287     // Parameter Length
1288     big_endian_store_16(connection->cmd_operands, pos, 9);
1289     pos += 2;
1290 
1291     // write 8 bytes value
1292     memset(connection->cmd_operands + pos, 0, 8); // identifier: PLAYING
1293     pos += 8;
1294 
1295     connection->cmd_operands[pos++] = 0; // attribute count, if 0 get all attributes
1296     // every attribute is 4 bytes long
1297 
1298     connection->cmd_operands_length = pos;
1299     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1300     return ERROR_CODE_SUCCESS;
1301 }
1302 
1303 uint8_t avrcp_controller_set_absolute_volume(uint16_t avrcp_cid, uint8_t volume){
1304      avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1305     if (!connection){
1306         log_error("avrcp_get_capabilities: could not find a connection.");
1307         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1308     }
1309     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1310     connection->state = AVCTP_W2_SEND_COMMAND;
1311 
1312     connection->transaction_label++;
1313     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1314     connection->command_type = AVRCP_CTYPE_CONTROL;
1315     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1316     connection->subunit_id = AVRCP_SUBUNIT_ID;
1317     int pos = 0;
1318     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1319     pos += 3;
1320     connection->cmd_operands[pos++] = AVRCP_PDU_ID_SET_ABSOLUTE_VOLUME; // PDU ID
1321     connection->cmd_operands[pos++] = 0;
1322 
1323     // Parameter Length
1324     big_endian_store_16(connection->cmd_operands, pos, 1);
1325     pos += 2;
1326     connection->cmd_operands[pos++] = volume;
1327 
1328     connection->cmd_operands_length = pos;
1329     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1330     return ERROR_CODE_SUCCESS;
1331 }
1332 
1333 uint8_t avrcp_controller_query_shuffle_and_repeat_modes(uint16_t avrcp_cid){
1334     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1335     if (!connection){
1336         log_error("avrcp_get_capabilities: could not find a connection.");
1337         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1338     }
1339     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1340     connection->state = AVCTP_W2_SEND_COMMAND;
1341 
1342     connection->transaction_label++;
1343     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1344     connection->command_type = AVRCP_CTYPE_STATUS;
1345     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1346     connection->subunit_id = AVRCP_SUBUNIT_ID;
1347     big_endian_store_24(connection->cmd_operands, 0, BT_SIG_COMPANY_ID);
1348     connection->cmd_operands[3] = AVRCP_PDU_ID_GET_CURRENT_PLAYER_APPLICATION_SETTING_VALUE; // PDU ID
1349     connection->cmd_operands[4] = 0;
1350     big_endian_store_16(connection->cmd_operands, 5, 5); // parameter length
1351     connection->cmd_operands[7] = 4;                     // NumPlayerApplicationSettingAttributeID
1352     // PlayerApplicationSettingAttributeID1 AVRCP Spec, Appendix F, 133
1353     connection->cmd_operands[8]  = 0x01;    // equalizer  (1-OFF, 2-ON)
1354     connection->cmd_operands[9]  = 0x02;    // repeat     (1-off, 2-single track, 3-all tracks, 4-group repeat)
1355     connection->cmd_operands[10] = 0x03;    // shuffle    (1-off, 2-all tracks, 3-group shuffle)
1356     connection->cmd_operands[11] = 0x04;    // scan       (1-off, 2-all tracks, 3-group scan)
1357     connection->cmd_operands_length = 12;
1358     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1359     return ERROR_CODE_SUCCESS;
1360 }
1361 
1362 static uint8_t avrcp_controller_set_current_player_application_setting_value(uint16_t avrcp_cid, uint8_t attr_id, uint8_t attr_value){
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_capabilities: could not find a connection.");
1366         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1367     }
1368     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1369     connection->state = AVCTP_W2_SEND_COMMAND;
1370 
1371     connection->transaction_label++;
1372     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1373     connection->command_type = AVRCP_CTYPE_CONTROL;
1374     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1375     connection->subunit_id = AVRCP_SUBUNIT_ID;
1376     int pos = 0;
1377     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1378     pos += 3;
1379     connection->cmd_operands[pos++] = AVRCP_PDU_ID_SET_PLAYER_APPLICATION_SETTING_VALUE; // PDU ID
1380     connection->cmd_operands[pos++] = 0;
1381     // Parameter Length
1382     big_endian_store_16(connection->cmd_operands, pos, 3);
1383     pos += 2;
1384     connection->cmd_operands[pos++] = 2;
1385     connection->cmd_operands_length = pos;
1386     connection->cmd_operands[pos++]  = attr_id;
1387     connection->cmd_operands[pos++]  = attr_value;
1388     connection->cmd_operands_length = pos;
1389     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1390     return ERROR_CODE_SUCCESS;
1391 }
1392 
1393 uint8_t avrcp_controller_set_shuffle_mode(uint16_t avrcp_cid, avrcp_shuffle_mode_t mode){
1394     if ((mode < AVRCP_SHUFFLE_MODE_OFF) || (mode > AVRCP_SHUFFLE_MODE_GROUP)) return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
1395     return avrcp_controller_set_current_player_application_setting_value(avrcp_cid, 0x03, mode);
1396 }
1397 
1398 uint8_t avrcp_controller_set_repeat_mode(uint16_t avrcp_cid, avrcp_repeat_mode_t mode){
1399     if ((mode < AVRCP_REPEAT_MODE_OFF) || (mode > AVRCP_REPEAT_MODE_GROUP)) return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
1400     return avrcp_controller_set_current_player_application_setting_value(avrcp_cid, 0x02, mode);
1401 }
1402 
1403 uint8_t avrcp_controller_play_item_for_scope(uint16_t avrcp_cid, uint8_t * uid, uint16_t uid_counter, avrcp_browsing_scope_t scope){
1404     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1405     if (!connection){
1406         log_error("Could not find a connection with cid 0%02x.", avrcp_cid);
1407         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1408     }
1409     if (connection->state != AVCTP_CONNECTION_OPENED){
1410         log_error("Connection in wrong state, expected %d, received %d", AVCTP_CONNECTION_OPENED, connection->state);
1411         return ERROR_CODE_COMMAND_DISALLOWED;
1412     }
1413     connection->state = AVCTP_W2_SEND_COMMAND;
1414 
1415     connection->transaction_label++;
1416     connection->command_type = AVRCP_CTYPE_CONTROL;
1417     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1418     connection->subunit_id = AVRCP_SUBUNIT_ID;
1419     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1420     int pos = 0;
1421     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1422     pos += 3;
1423     connection->cmd_operands[pos++] = AVRCP_PDU_ID_PLAY_ITEM; // PDU ID
1424     // reserved
1425     connection->cmd_operands[pos++] = 0;
1426     // Parameter Length
1427     big_endian_store_16(connection->cmd_operands, pos, 11);
1428     pos += 2;
1429     connection->cmd_operands[pos++]  = scope;
1430     memset(&connection->cmd_operands[pos], 0, 8);
1431     if (uid){
1432         (void)memcpy(&connection->cmd_operands[pos], uid, 8);
1433     }
1434     pos += 8;
1435     big_endian_store_16(connection->cmd_operands, pos, uid_counter);
1436     pos += 2;
1437     connection->cmd_operands_length = pos;
1438 
1439     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1440     return ERROR_CODE_SUCCESS;
1441 }
1442 
1443 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){
1444     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1445     if (!connection){
1446         log_error("Could not find a connection with cid 0%02x.", avrcp_cid);
1447         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1448     }
1449     if (connection->state != AVCTP_CONNECTION_OPENED){
1450         log_error("Connection in wrong state, expected %d, received %d", AVCTP_CONNECTION_OPENED, connection->state);
1451         return ERROR_CODE_COMMAND_DISALLOWED;
1452     }
1453     connection->state = AVCTP_W2_SEND_COMMAND;
1454 
1455     connection->transaction_label++;
1456     connection->command_type = AVRCP_CTYPE_CONTROL;
1457     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1458     connection->subunit_id = AVRCP_SUBUNIT_ID;
1459     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1460     int pos = 0;
1461     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1462     pos += 3;
1463     connection->cmd_operands[pos++] = AVRCP_PDU_ID_ADD_TO_NOW_PLAYING; // PDU ID
1464     // reserved
1465     connection->cmd_operands[pos++] = 0;
1466     // Parameter Length
1467     big_endian_store_16(connection->cmd_operands, pos, 11);
1468     pos += 2;
1469     connection->cmd_operands[pos++]  = scope;
1470     memset(&connection->cmd_operands[pos], 0, 8);
1471     if (uid){
1472         (void)memcpy(&connection->cmd_operands[pos], uid, 8);
1473     }
1474     pos += 8;
1475     big_endian_store_16(connection->cmd_operands, pos, uid_counter);
1476     pos += 2;
1477     connection->cmd_operands_length = pos;
1478 
1479     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1480     return ERROR_CODE_SUCCESS;
1481 }
1482 
1483 uint8_t avrcp_controller_set_max_num_fragments(uint16_t avrcp_cid, uint8_t max_num_fragments){
1484     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1485     if (!connection){
1486         log_error("avrcp_controller_play_item: could not find a connection.");
1487         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1488     }
1489     connection->max_num_fragments = max_num_fragments;
1490     return ERROR_CODE_SUCCESS;
1491 }
1492 
1493 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){
1494     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1495     if (!connection){
1496         log_error("avrcp_controller_play_item: could not find a connection.");
1497         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1498     }
1499 
1500     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1501     connection->state = AVCTP_W2_SEND_FRAGMENTED_COMMAND;
1502 
1503     connection->transaction_label++;
1504     connection->command_opcode = command_opcode;
1505     connection->command_type = command_type;
1506     connection->subunit_type = subunit_type;
1507     connection->subunit_id = subunit_id;
1508     connection->cmd_operands_fragmented_buffer = command_buffer;
1509     connection->cmd_operands_fragmented_pos = 0;
1510     connection->cmd_operands_fragmented_len = command_len;
1511 
1512     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1513     return ERROR_CODE_SUCCESS;
1514 }
1515