xref: /btstack/src/classic/avrcp_controller.c (revision 4783d25609a5032739e1b6e67d2236f2d80f2100)
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 <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <inttypes.h>
45 
46 #include "btstack.h"
47 #include "classic/avrcp.h"
48 #include "classic/avrcp_controller.h"
49 
50 // made public in avrcp_controller.h
51 avrcp_context_t avrcp_controller_context;
52 
53 static int avrcp_controller_supports_browsing(uint16_t controller_supported_features){
54     return controller_supported_features & (1 << AVRCP_CONTROLLER_SUPPORTED_FEATURE_BROWSING);
55 }
56 
57 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){
58     avrcp_create_sdp_record(1, service, service_record_handle, avrcp_controller_supports_browsing(supported_features), supported_features, service_name, service_provider_name);
59 }
60 
61 static void avrcp_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){
62     btstack_assert(callback != NULL);
63 
64     uint8_t event[8];
65     int pos = 0;
66     event[pos++] = HCI_EVENT_AVRCP_META;
67     event[pos++] = sizeof(event) - 2;
68     event[pos++] = AVRCP_SUBEVENT_SHUFFLE_AND_REPEAT_MODE;
69     little_endian_store_16(event, pos, avrcp_cid);
70     pos += 2;
71     event[pos++] = ctype;
72     event[pos++] = repeat_mode;
73     event[pos++] = shuffle_mode;
74     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
75 }
76 
77 static void avrcp_emit_operation_status(btstack_packet_handler_t callback, uint8_t subevent, uint16_t avrcp_cid, uint8_t ctype, uint8_t operation_id){
78     btstack_assert(callback != NULL);
79 
80     uint8_t event[7];
81     int pos = 0;
82     event[pos++] = HCI_EVENT_AVRCP_META;
83     event[pos++] = sizeof(event) - 2;
84     event[pos++] = subevent;
85     little_endian_store_16(event, pos, avrcp_cid);
86     pos += 2;
87     event[pos++] = ctype;
88     event[pos++] = operation_id;
89     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
90 }
91 
92 static void avrcp_press_and_hold_timeout_handler(btstack_timer_source_t * timer){
93     UNUSED(timer);
94     avrcp_connection_t * connection = (avrcp_connection_t*) btstack_run_loop_get_timer_context(timer);
95     btstack_run_loop_set_timer(&connection->press_and_hold_cmd_timer, 2000); // 2 seconds timeout
96     btstack_run_loop_add_timer(&connection->press_and_hold_cmd_timer);
97     connection->state = AVCTP_W2_SEND_PRESS_COMMAND;
98     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
99 }
100 
101 static void avrcp_press_and_hold_timer_start(avrcp_connection_t * connection){
102     btstack_run_loop_remove_timer(&connection->press_and_hold_cmd_timer);
103     btstack_run_loop_set_timer_handler(&connection->press_and_hold_cmd_timer, avrcp_press_and_hold_timeout_handler);
104     btstack_run_loop_set_timer_context(&connection->press_and_hold_cmd_timer, connection);
105     btstack_run_loop_set_timer(&connection->press_and_hold_cmd_timer, 2000); // 2 seconds timeout
106     btstack_run_loop_add_timer(&connection->press_and_hold_cmd_timer);
107 }
108 
109 static void avrcp_press_and_hold_timer_stop(avrcp_connection_t * connection){
110     connection->continuous_fast_forward_cmd = 0;
111     btstack_run_loop_remove_timer(&connection->press_and_hold_cmd_timer);
112 }
113 
114 static uint8_t request_pass_through_release_control_cmd(avrcp_connection_t * connection){
115     connection->state = AVCTP_W2_SEND_RELEASE_COMMAND;
116     if (connection->continuous_fast_forward_cmd){
117         avrcp_press_and_hold_timer_stop(connection);
118     }
119     connection->cmd_operands[0] = 0x80 | connection->cmd_operands[0];
120     connection->transaction_label++;
121     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
122     return ERROR_CODE_SUCCESS;
123 }
124 
125 static inline uint8_t 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){
126     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
127     if (!connection){
128         log_error("avrcp: could not find a connection. avrcp cid 0x%02x", avrcp_cid);
129         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
130     }
131 
132     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
133     connection->state = AVCTP_W2_SEND_PRESS_COMMAND;
134     connection->command_opcode =  AVRCP_CMD_OPCODE_PASS_THROUGH;
135     connection->command_type = AVRCP_CTYPE_CONTROL;
136     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
137     connection->subunit_id =   AVRCP_SUBUNIT_ID;
138     connection->cmd_operands_length = 0;
139 
140     connection->continuous_fast_forward_cmd = continuous_fast_forward_cmd;
141     connection->cmd_operands_length = 2;
142     connection->cmd_operands[0] = opid;
143     if (playback_speed > 0){
144         connection->cmd_operands[2] = playback_speed;
145         connection->cmd_operands_length++;
146     }
147     connection->cmd_operands[1] = connection->cmd_operands_length - 2;
148 
149     if (connection->continuous_fast_forward_cmd){
150         avrcp_press_and_hold_timer_start(connection);
151     }
152 
153     connection->transaction_label++;
154     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
155     return ERROR_CODE_SUCCESS;
156 }
157 
158 static uint8_t request_single_pass_through_press_control_cmd(uint16_t avrcp_cid, avrcp_operation_id_t opid, uint16_t playback_speed){
159     return request_pass_through_press_control_cmd(avrcp_cid, opid, playback_speed, 0);
160 }
161 
162 static uint8_t request_continuous_pass_through_press_control_cmd(uint16_t avrcp_cid, avrcp_operation_id_t opid, uint16_t playback_speed){
163     return request_pass_through_press_control_cmd(avrcp_cid, opid, playback_speed, 1);
164 }
165 
166 #define AVRCP_CMD_BUFFER_SIZE 30
167 static uint16_t avrcp_get_max_payload_size_for_packet_type(avrcp_packet_type_t packet_type){
168     switch (packet_type){
169         case AVRCP_SINGLE_PACKET:
170             return AVRCP_CMD_BUFFER_SIZE - 3;
171         case AVRCP_START_PACKET:
172             return AVRCP_CMD_BUFFER_SIZE - 4;
173         case AVRCP_CONTINUE_PACKET:
174         case AVRCP_END_PACKET:
175             return AVRCP_CMD_BUFFER_SIZE - 1;
176     }
177     return 0;
178 }
179 
180 static int avrcp_send_cmd(avrcp_connection_t * connection, avrcp_packet_type_t packet_type){
181     uint8_t command[AVRCP_CMD_BUFFER_SIZE];
182     int pos = 0;
183     uint16_t max_bytes = sizeof(command) - 1;
184 
185     // transport header
186     // Transaction label | Packet_type | C/R | IPID (1 == invalid profile identifier)
187     command[pos++] = (connection->transaction_label << 4) | (packet_type << 2) | (AVRCP_COMMAND_FRAME << 1) | 0;
188 
189     if (packet_type == AVRCP_START_PACKET){
190         // num packets: (3 bytes overhead (PID, num packets) + command) / (MTU - transport header)
191         command[pos++] = ((connection->cmd_operands_fragmented_len + 3 - 1) / (AVRCP_CMD_BUFFER_SIZE - 1)) + 1;
192         max_bytes -= 3;
193     }
194 
195     if ((packet_type == AVRCP_SINGLE_PACKET) || (packet_type == AVRCP_START_PACKET)){
196         // Profile IDentifier (PID)
197         command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL >> 8;
198         command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL & 0x00FF;
199 
200         // command_type
201         command[pos++] = connection->command_type;
202         // subunit_type | subunit ID
203         command[pos++] = (connection->subunit_type << 3) | connection->subunit_id;
204         // opcode
205         command[pos++] = (uint8_t)connection->command_opcode;
206     }
207 
208     if (packet_type == AVRCP_SINGLE_PACKET){
209         // operands
210         (void)memcpy(command + pos, connection->cmd_operands,
211                      connection->cmd_operands_length);
212         pos += connection->cmd_operands_length;
213     } else {
214         uint16_t bytes_to_copy = btstack_min(connection->cmd_operands_fragmented_len-connection->cmd_operands_fragmented_pos, max_bytes);
215         (void)memcpy(command + pos,
216                      &connection->cmd_operands_fragmented_buffer[connection->cmd_operands_fragmented_pos],
217                      bytes_to_copy);
218         pos += bytes_to_copy;
219         connection->cmd_operands_fragmented_pos += bytes_to_copy;
220     }
221 
222     return l2cap_send(connection->l2cap_signaling_cid, command, pos);
223 }
224 
225 static int avrcp_register_notification(avrcp_connection_t * connection, avrcp_notification_event_id_t event_id){
226     if (connection->notifications_to_deregister & (1 << event_id)) return 0;
227     if (connection->notifications_enabled & (1 << event_id)) return 0;
228     if (connection->notifications_to_register & (1 << event_id)) return 0;
229     connection->notifications_to_register |= (1 << event_id);
230     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
231     return 1;
232 }
233 
234 static void avrcp_prepare_notification(avrcp_connection_t * connection, avrcp_notification_event_id_t event_id){
235     connection->transaction_label++;
236     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
237     connection->command_type = AVRCP_CTYPE_NOTIFY;
238     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
239     connection->subunit_id = AVRCP_SUBUNIT_ID;
240     int pos = 0;
241     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
242     pos += 3;
243     connection->cmd_operands[pos++] = AVRCP_PDU_ID_REGISTER_NOTIFICATION;
244     connection->cmd_operands[pos++] = 0;                     // reserved(upper 6) | packet_type -> 0
245     big_endian_store_16(connection->cmd_operands, pos, 5);     // parameter length
246     pos += 2;
247     connection->cmd_operands[pos++] = event_id;
248     big_endian_store_32(connection->cmd_operands, pos, 1); // send notification on playback position every second, for other notifications it is ignored
249     pos += 4;
250     connection->cmd_operands_length = pos;
251     // AVRCP_SPEC_V14.pdf 166
252     // answer page 61
253 }
254 
255 
256 static void avrcp_parser_reset(avrcp_connection_t * connection){
257     connection->list_offset = 0;
258     connection->num_attributes = 0;
259     connection->num_parsed_attributes = 0;
260     connection->parser_attribute_header_pos = 0;
261     connection->num_received_fragments = 0;
262     connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_HEADER;
263 }
264 
265 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){
266     uint8_t event[7];
267     int pos = 0;
268     event[pos++] = HCI_EVENT_AVRCP_META;
269     event[pos++] = sizeof(event) - 2;
270     event[pos++] = AVRCP_SUBEVENT_NOW_PLAYING_INFO_DONE;
271     little_endian_store_16(event, pos, avrcp_cid);
272     pos += 2;
273     event[pos++] = ctype;
274     event[pos++] = status;
275     // printf_hexdump(event, pos);
276     (*callback)(HCI_EVENT_PACKET, 0, event, pos);
277 }
278 
279 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){
280     uint8_t event[HCI_EVENT_BUFFER_SIZE];
281     int pos = 0;
282     event[pos++] = HCI_EVENT_AVRCP_META;
283     // reserve one byte for subevent type and data len
284     int data_len_pos = pos;
285     pos++;
286     int subevent_type_pos = pos;
287     pos++;
288     little_endian_store_16(event, pos, avrcp_cid);
289     pos += 2;
290     event[pos++] = ctype;
291 
292     switch (attr_id){
293         case AVRCP_MEDIA_ATTR_TITLE:
294             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TITLE_INFO;
295             event[pos++] = value_len;
296             (void)memcpy(event + pos, value, value_len);
297             break;
298         case AVRCP_MEDIA_ATTR_ARTIST:
299             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_ARTIST_INFO;
300             event[pos++] = value_len;
301             (void)memcpy(event + pos, value, value_len);
302             break;
303         case AVRCP_MEDIA_ATTR_ALBUM:
304             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_ALBUM_INFO;
305             event[pos++] = value_len;
306             (void)memcpy(event + pos, value, value_len);
307             break;
308         case AVRCP_MEDIA_ATTR_GENRE:
309             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_GENRE_INFO;
310             event[pos++] = value_len;
311             (void)memcpy(event + pos, value, value_len);
312             break;
313         case AVRCP_MEDIA_ATTR_SONG_LENGTH_MS:
314             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_SONG_LENGTH_MS_INFO;
315             if (value){
316                 little_endian_store_32(event, pos, btstack_atoi((char *)value));
317             } else {
318                 little_endian_store_32(event, pos, 0);
319             }
320             pos += 4;
321             break;
322         case AVRCP_MEDIA_ATTR_TRACK:
323             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TRACK_INFO;
324             if (value){
325                 event[pos++] = btstack_atoi((char *)value);
326             } else {
327                 event[pos++] = 0;
328             }
329             break;
330         case AVRCP_MEDIA_ATTR_TOTAL_NUM_ITEMS:
331             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TOTAL_TRACKS_INFO;
332             if (value){
333                 event[pos++] = btstack_atoi((char *)value);
334             } else {
335                 event[pos++] = 0;
336             }
337             break;
338         default:
339             break;
340     }
341     event[data_len_pos] = pos - 2;
342     (*callback)(HCI_EVENT_PACKET, 0, event, pos);
343 }
344 
345 static void avrcp_parser_process_byte(uint8_t byte, avrcp_connection_t * connection, avrcp_command_type_t ctype){
346     uint16_t attribute_total_value_len;
347     uint32_t attribute_id;
348     // printf("avrcp_parser_process_byte: %02x, state %02x\n", byte, connection->parser_state);
349     switch(connection->parser_state){
350         case AVRCP_PARSER_GET_ATTRIBUTE_HEADER:
351             connection->parser_attribute_header[connection->parser_attribute_header_pos++] = byte;
352             connection->list_offset++;
353 
354             if (connection->parser_attribute_header_pos < AVRCP_ATTRIBUTE_HEADER_LEN) return;
355 
356             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
357             connection->attribute_value_len = btstack_min(attribute_total_value_len, AVRCP_MAX_ATTRIBUTTE_SIZE);
358             if (connection->attribute_value_len > 0){
359                 // get ready for attribute value
360                 connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_VALUE;
361                 return;
362             }
363 
364             // emit empty attribute
365             attribute_id = big_endian_read_32(connection->parser_attribute_header, 0);
366             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);
367 
368             // done, see below
369             break;
370 
371         case AVRCP_PARSER_GET_ATTRIBUTE_VALUE:
372             connection->attribute_value[connection->attribute_value_offset++] = byte;
373             connection->list_offset++;
374 
375             if (connection->attribute_value_offset < connection->attribute_value_len) return;
376 
377             // emit (potentially partial) attribute
378             attribute_id = big_endian_read_32(connection->parser_attribute_header, 0);
379             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);
380 
381             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
382             if (connection->attribute_value_offset < attribute_total_value_len){
383                 // ignore rest of attribute
384                 connection->parser_state = AVRCP_PARSER_IGNORE_REST_OF_ATTRIBUTE_VALUE;
385                 return;
386             }
387 
388             // done, see below
389             break;
390 
391         case AVRCP_PARSER_IGNORE_REST_OF_ATTRIBUTE_VALUE:
392             connection->attribute_value_offset++;
393             connection->list_offset++;
394 
395             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
396             if (connection->attribute_value_offset < attribute_total_value_len) return;
397 
398             // done, see below
399             break;
400 
401         default:
402             return;
403     }
404 
405     // attribute fully read, check if more to come
406     if (connection->list_offset < connection->list_size){
407         // more to come, reset parser
408         connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_HEADER;
409         connection->parser_attribute_header_pos = 0;
410         connection->attribute_value_offset = 0;
411     } else {
412         // fully done
413         avrcp_parser_reset(connection);
414         avrcp_controller_emit_now_playing_info_event_done(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, 0);
415     }
416 }
417 
418 static void avrcp_source_parse_and_emit_element_attrs(uint8_t * packet, uint16_t num_bytes_to_read, avrcp_connection_t * connection, avrcp_command_type_t ctype){
419     int i;
420     for (i=0;i<num_bytes_to_read;i++){
421         avrcp_parser_process_byte(packet[i], connection, ctype);
422     }
423 }
424 
425 static uint8_t avrcp_controller_request_abort_continuation(avrcp_connection_t * connection){
426     connection->state = AVCTP_W2_SEND_COMMAND;
427     connection->transaction_label++;
428     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
429     connection->command_type = AVRCP_CTYPE_CONTROL;
430     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
431     connection->subunit_id = AVRCP_SUBUNIT_ID;
432     int pos = 0;
433     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
434     pos += 3;
435     connection->cmd_operands[pos++] = AVRCP_PDU_ID_REQUEST_ABORT_CONTINUING_RESPONSE; // PDU ID
436     connection->cmd_operands[pos++] = 0;
437     // Parameter Length
438     connection->cmd_operands_length = 8;
439     big_endian_store_16(connection->cmd_operands, pos, 1);
440     pos += 2;
441     connection->cmd_operands[pos++] = AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES;
442     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
443     return ERROR_CODE_SUCCESS;
444 }
445 
446 
447 static uint8_t avrcp_controller_request_continue_response(avrcp_connection_t * connection){
448     connection->state = AVCTP_W2_SEND_COMMAND;
449     connection->transaction_label++;
450     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
451     connection->command_type = AVRCP_CTYPE_CONTROL;
452     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
453     connection->subunit_id = AVRCP_SUBUNIT_ID;
454     int pos = 0;
455     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
456     pos += 3;
457     connection->cmd_operands[pos++] = AVRCP_PDU_ID_REQUEST_CONTINUING_RESPONSE; // PDU ID
458     connection->cmd_operands[pos++] = 0;
459     // Parameter Length
460     connection->cmd_operands_length = 8;
461     big_endian_store_16(connection->cmd_operands, pos, 1);
462     pos += 2;
463     connection->cmd_operands[pos++] = AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES;
464     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
465     return ERROR_CODE_SUCCESS;
466 }
467 
468 static void avrcp_handle_l2cap_data_packet_for_signaling_connection(avrcp_connection_t * connection, uint8_t *packet, uint16_t size){
469     uint8_t operands[20];
470     uint8_t opcode;
471     int     pos = 3;
472 
473     avrcp_command_type_t ctype = (avrcp_command_type_t) packet[pos++];
474     uint8_t byte_value = packet[pos++];
475     avrcp_subunit_type_t subunit_type = (avrcp_subunit_type_t) (byte_value >> 3);
476     avrcp_subunit_type_t subunit_id = (avrcp_subunit_type_t)   (byte_value & 0x07);
477     opcode = packet[pos++];
478 
479     uint8_t pdu_id;
480     uint16_t param_length;
481     switch (avrcp_cmd_opcode(packet,size)){
482         case AVRCP_CMD_OPCODE_SUBUNIT_INFO:{
483             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE) return;
484             connection->state = AVCTP_CONNECTION_OPENED;
485             // operands:
486             (void)memcpy(operands, packet + pos, 5);
487             uint8_t unit_type = operands[1] >> 3;
488             uint8_t max_subunit_ID = operands[1] & 0x07;
489             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);
490             break;
491         }
492         case AVRCP_CMD_OPCODE_UNIT_INFO:{
493             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE) return;
494             connection->state = AVCTP_CONNECTION_OPENED;
495             // operands:
496             (void)memcpy(operands, packet + pos, 5);
497             uint8_t unit_type = operands[1] >> 3;
498             uint8_t unit = operands[1] & 0x07;
499             uint32_t company_id = (operands[2] << 16) | (operands[3] << 8) | operands[4];
500             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,
501                 ctype, subunit_type, subunit_id, opcode, unit_type, unit, company_id);
502             break;
503         }
504         case AVRCP_CMD_OPCODE_VENDOR_DEPENDENT:
505             if ((size - pos) < 7) {
506                 log_error("avrcp: wrong packet size");
507                 return;
508             };
509             // operands:
510             (void)memcpy(operands, packet + pos, 7);
511             pos += 7;
512             pdu_id = operands[3];
513 
514             if ((connection->state != AVCTP_W2_RECEIVE_RESPONSE) && (pdu_id != AVRCP_PDU_ID_REGISTER_NOTIFICATION)){
515                 log_info("AVRCP_CMD_OPCODE_VENDOR_DEPENDENT state %d", connection->state);
516                 return;
517             }
518             connection->state = AVCTP_CONNECTION_OPENED;
519 
520             param_length = big_endian_read_16(operands, 5);
521 
522             log_info("        VENDOR DEPENDENT response: pdu id 0x%02x, param_length %d, status %s", pdu_id, param_length, avrcp_ctype2str(ctype));
523             switch (pdu_id){
524                 case AVRCP_PDU_ID_GetCurrentPlayerApplicationSettingValue:{
525                     uint8_t num_attributes = packet[pos++];
526                     int i;
527                     avrcp_repeat_mode_t  repeat_mode =  AVRCP_REPEAT_MODE_INVALID;
528                     avrcp_shuffle_mode_t shuffle_mode = AVRCP_SHUFFLE_MODE_INVALID;
529                     for (i = 0; i < num_attributes; i++){
530                         uint8_t attribute_id    = packet[pos++];
531                         uint8_t value = packet[pos++];
532                         switch (attribute_id){
533                             case 0x02:
534                                 repeat_mode = (avrcp_repeat_mode_t) value;
535                                 break;
536                             case 0x03:
537                                 shuffle_mode = (avrcp_shuffle_mode_t) value;
538                                 break;
539                             default:
540                                 break;
541                         }
542                     }
543                     avrcp_emit_repeat_and_shuffle_mode(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, repeat_mode, shuffle_mode);
544                     break;
545                 }
546                 case AVRCP_PDU_ID_SetPlayerApplicationSettingValue:{
547                     uint8_t event[6];
548                     int offset = 0;
549                     event[offset++] = HCI_EVENT_AVRCP_META;
550                     event[offset++] = sizeof(event) - 2;
551                     event[offset++] = AVRCP_SUBEVENT_PLAYER_APPLICATION_VALUE_RESPONSE;
552                     little_endian_store_16(event, offset, connection->avrcp_cid);
553                     offset += 2;
554                     event[offset++] = ctype;
555                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
556                     break;
557                 }
558                 case AVRCP_PDU_ID_SET_ABSOLUTE_VOLUME:{
559                     uint8_t event[7];
560                     int offset = 0;
561                     event[offset++] = HCI_EVENT_AVRCP_META;
562                     event[offset++] = sizeof(event) - 2;
563                     event[offset++] = AVRCP_SUBEVENT_SET_ABSOLUTE_VOLUME_RESPONSE;
564                     little_endian_store_16(event, offset, connection->avrcp_cid);
565                     offset += 2;
566                     event[offset++] = ctype;
567                     event[offset++] = packet[pos++];
568                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
569                     break;
570                 }
571                 case AVRCP_PDU_ID_GET_CAPABILITIES:{
572                     avrcp_capability_id_t capability_id = (avrcp_capability_id_t) packet[pos++];
573                     uint8_t capability_count = packet[pos++];
574                     int i;
575                     switch (capability_id){
576                         case AVRCP_CAPABILITY_ID_COMPANY:
577                             for (i = 0; i < capability_count; i++){
578                                 uint32_t company_id = big_endian_read_24(packet, pos);
579                                 pos += 3;
580                                 log_info("  0x%06" PRIx32 ", ", company_id);
581                             }
582                             break;
583                         case AVRCP_CAPABILITY_ID_EVENT:
584                             for (i = 0; i < capability_count; i++){
585                                 uint8_t event_id = packet[pos++];
586                                 log_info("  0x%02x %s", event_id, avrcp_event2str(event_id));
587                             }
588                             break;
589                     }
590                     break;
591                 }
592                 case AVRCP_PDU_ID_GET_PLAY_STATUS:{
593                     uint32_t song_length = big_endian_read_32(packet, pos);
594                     pos += 4;
595                     uint32_t song_position = big_endian_read_32(packet, pos);
596                     pos += 4;
597                     uint8_t play_status = packet[pos];
598 
599                     uint8_t event[15];
600                     int offset = 0;
601                     event[offset++] = HCI_EVENT_AVRCP_META;
602                     event[offset++] = sizeof(event) - 2;
603                     event[offset++] = AVRCP_SUBEVENT_PLAY_STATUS;
604                     little_endian_store_16(event, offset, connection->avrcp_cid);
605                     offset += 2;
606                     event[offset++] = ctype;
607                     little_endian_store_32(event, offset, song_length);
608                     offset += 4;
609                     little_endian_store_32(event, offset, song_position);
610                     offset += 4;
611                     event[offset++] = play_status;
612                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
613                     break;
614                 }
615                 case AVRCP_PDU_ID_REGISTER_NOTIFICATION:{
616                     avrcp_notification_event_id_t  event_id = (avrcp_notification_event_id_t) packet[pos++];
617                     uint16_t event_mask = (1 << event_id);
618                     uint16_t reset_event_mask = ~event_mask;
619                     switch (ctype){
620                         case AVRCP_CTYPE_RESPONSE_INTERIM:
621                             // register as enabled
622                             connection->notifications_enabled |= event_mask;
623                             break;
624                         case AVRCP_CTYPE_RESPONSE_CHANGED_STABLE:
625                             // received change, event is considered deregistered
626                             // we are re-enabling it automatically, if it is not
627                             // explicitly disabled
628                             connection->notifications_enabled &= reset_event_mask;
629                             if (! (connection->notifications_to_deregister & event_mask)){
630                                 avrcp_register_notification(connection, event_id);
631                             } else {
632                                 connection->notifications_to_deregister &= reset_event_mask;
633                             }
634                             break;
635                         default:
636                             connection->notifications_to_register &= reset_event_mask;
637                             connection->notifications_enabled &= reset_event_mask;
638                             connection->notifications_to_deregister &= reset_event_mask;
639                             break;
640                     }
641 
642                     switch (event_id){
643                         case AVRCP_NOTIFICATION_EVENT_PLAYBACK_POS_CHANGED:{
644                             uint32_t song_position = big_endian_read_32(packet, pos);
645                             uint8_t event[10];
646                             int offset = 0;
647                             event[offset++] = HCI_EVENT_AVRCP_META;
648                             event[offset++] = sizeof(event) - 2;
649                             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_PLAYBACK_POS_CHANGED;
650                             little_endian_store_16(event, offset, connection->avrcp_cid);
651                             offset += 2;
652                             event[offset++] = ctype;
653                             little_endian_store_32(event, offset, song_position);
654                             offset += 4;
655                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
656                             break;
657                         }
658                         case AVRCP_NOTIFICATION_EVENT_PLAYBACK_STATUS_CHANGED:{
659                             uint8_t event[7];
660                             int offset = 0;
661                             event[offset++] = HCI_EVENT_AVRCP_META;
662                             event[offset++] = sizeof(event) - 2;
663                             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_PLAYBACK_STATUS_CHANGED;
664                             little_endian_store_16(event, offset, connection->avrcp_cid);
665                             offset += 2;
666                             event[offset++] = ctype;
667                             event[offset++] = packet[pos];
668                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
669                             break;
670                         }
671                         case AVRCP_NOTIFICATION_EVENT_TRACK_CHANGED:{
672                             uint8_t event[6];
673                             int offset = 0;
674                             event[offset++] = HCI_EVENT_AVRCP_META;
675                             event[offset++] = sizeof(event) - 2;
676                             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_TRACK_CHANGED;
677                             little_endian_store_16(event, offset, connection->avrcp_cid);
678                             offset += 2;
679                             event[offset++] = ctype;
680                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
681                             break;
682                         }
683                         case AVRCP_NOTIFICATION_EVENT_NOW_PLAYING_CONTENT_CHANGED:{
684                             uint8_t event[6];
685                             int offset = 0;
686                             event[offset++] = HCI_EVENT_AVRCP_META;
687                             event[offset++] = sizeof(event) - 2;
688                             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_NOW_PLAYING_CONTENT_CHANGED;
689                             little_endian_store_16(event, offset, connection->avrcp_cid);
690                             offset += 2;
691                             event[offset++] = ctype;
692                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
693                             break;
694                         }
695                         case AVRCP_NOTIFICATION_EVENT_AVAILABLE_PLAYERS_CHANGED:{
696                             uint8_t event[6];
697                             int offset = 0;
698                             event[offset++] = HCI_EVENT_AVRCP_META;
699                             event[offset++] = sizeof(event) - 2;
700                             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_AVAILABLE_PLAYERS_CHANGED;
701                             little_endian_store_16(event, offset, connection->avrcp_cid);
702                             offset += 2;
703                             event[offset++] = ctype;
704                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
705                             break;
706                         }
707                         case AVRCP_NOTIFICATION_EVENT_VOLUME_CHANGED:{
708                             uint8_t event[7];
709                             int offset = 0;
710                             event[offset++] = HCI_EVENT_AVRCP_META;
711                             event[offset++] = sizeof(event) - 2;
712                             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_VOLUME_CHANGED;
713                             little_endian_store_16(event, offset, connection->avrcp_cid);
714                             offset += 2;
715                             event[offset++] = ctype;
716                             event[offset++] = packet[pos++] & 0x7F;
717                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
718                             break;
719                         }
720                         case AVRCP_NOTIFICATION_EVENT_UIDS_CHANGED:{
721                             uint8_t event[8];
722                             uint16_t uuid = big_endian_read_16(packet, pos);
723                             int offset = 0;
724                             event[offset++] = HCI_EVENT_AVRCP_META;
725                             event[offset++] = sizeof(event) - 2;
726                             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_UIDS_CHANGED;
727                             little_endian_store_16(event, offset, connection->avrcp_cid);
728                             offset += 2;
729                             event[offset++] = ctype;
730                             little_endian_store_16(event, offset, uuid);
731                             offset += 2;
732                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
733                             break;
734                         }
735 
736                         case AVRCP_NOTIFICATION_EVENT_TRACK_REACHED_END:{
737                             uint8_t event[6];
738                             int offset = 0;
739                             event[offset++] = HCI_EVENT_AVRCP_META;
740                             event[offset++] = sizeof(event) - 2;
741                             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_TRACK_REACHED_END;
742                             little_endian_store_16(event, offset, connection->avrcp_cid);
743                             offset += 2;
744                             event[offset++] = ctype;
745                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
746                             break;
747                         }
748                         case AVRCP_NOTIFICATION_EVENT_TRACK_REACHED_START:{
749                             uint8_t event[6];
750                             int offset = 0;
751                             event[offset++] = HCI_EVENT_AVRCP_META;
752                             event[offset++] = sizeof(event) - 2;
753                             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_TRACK_REACHED_START;
754                             little_endian_store_16(event, offset, connection->avrcp_cid);
755                             offset += 2;
756                             event[offset++] = ctype;
757                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
758                             break;
759                         }
760                         case AVRCP_NOTIFICATION_EVENT_BATT_STATUS_CHANGED:{
761                             uint8_t event[7];
762                             int offset = 0;
763                             event[offset++] = HCI_EVENT_AVRCP_META;
764                             event[offset++] = sizeof(event) - 2;
765                             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_BATT_STATUS_CHANGED;
766                             little_endian_store_16(event, offset, connection->avrcp_cid);
767                             offset += 2;
768                             event[offset++] = ctype;
769                             event[offset++] = packet[pos++];
770                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
771                             break;
772                         }
773 
774                         case AVRCP_NOTIFICATION_EVENT_SYSTEM_STATUS_CHANGED:{
775                             uint8_t event[7];
776                             int offset = 0;
777                             event[offset++] = HCI_EVENT_AVRCP_META;
778                             event[offset++] = sizeof(event) - 2;
779                             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_SYSTEM_STATUS_CHANGED;
780                             little_endian_store_16(event, offset, connection->avrcp_cid);
781                             offset += 2;
782                             event[offset++] = ctype;
783                             event[offset++] = packet[pos];
784                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
785                             break;
786                         }
787 
788                         case AVRCP_NOTIFICATION_EVENT_PLAYER_APPLICATION_SETTING_CHANGED:
789                         default:
790                             log_info("avrcp: not implemented");
791                             break;
792                     }
793                     if (connection->notifications_to_register != 0){
794                         avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
795                     }
796                     break;
797                 }
798 
799                 case AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES:{
800                     avrcp_packet_type_t packet_type = (avrcp_packet_type_t) (operands[4] & 0x03);
801                     switch (packet_type){
802                         case AVRCP_START_PACKET:
803                         case AVRCP_SINGLE_PACKET:
804                             avrcp_parser_reset(connection);
805                             connection->list_size = param_length;
806                             connection->num_attributes = packet[pos++];
807 
808                             avrcp_source_parse_and_emit_element_attrs(packet+pos, size-pos, connection, ctype);
809 
810                             if (packet_type == AVRCP_START_PACKET){
811                                 avrcp_controller_request_continue_response(connection);
812                             }
813                             break;
814                         case AVRCP_CONTINUE_PACKET:
815                         case AVRCP_END_PACKET:
816                             connection->num_received_fragments++;
817                             if (connection->num_received_fragments < connection->max_num_fragments){
818                                 avrcp_source_parse_and_emit_element_attrs(packet+pos, size-pos, connection, ctype);
819                                 if (packet_type == AVRCP_CONTINUE_PACKET){
820                                     avrcp_controller_request_continue_response(connection);
821                                 }
822                             } else {
823                                 avrcp_controller_request_abort_continuation(connection);
824                                 avrcp_controller_emit_now_playing_info_event_done(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, 1);
825                                 avrcp_parser_reset(connection);
826                             }
827                             break;
828                     }
829                 }
830                 default:
831                     break;
832             }
833             break;
834         case AVRCP_CMD_OPCODE_PASS_THROUGH:{
835             // 0x80 | connection->cmd_operands[0]
836             uint8_t operation_id = packet[pos++];
837             switch (connection->state){
838                 case AVCTP_W2_RECEIVE_PRESS_RESPONSE:
839                     if (connection->continuous_fast_forward_cmd){
840                         connection->state = AVCTP_W4_STOP;
841                     } else {
842                         connection->state = AVCTP_W2_SEND_RELEASE_COMMAND;
843                     }
844                     break;
845                 case AVCTP_W2_RECEIVE_RESPONSE:
846                     connection->state = AVCTP_CONNECTION_OPENED;
847                     break;
848                 default:
849                     break;
850             }
851             if (connection->state == AVCTP_W4_STOP){
852                 avrcp_emit_operation_status(avrcp_controller_context.avrcp_callback, AVRCP_SUBEVENT_OPERATION_START, connection->avrcp_cid, ctype, operation_id);
853             }
854             if (connection->state == AVCTP_CONNECTION_OPENED) {
855                 // RELEASE response
856                 operation_id = operation_id & 0x7F;
857                 avrcp_emit_operation_status(avrcp_controller_context.avrcp_callback, AVRCP_SUBEVENT_OPERATION_COMPLETE, connection->avrcp_cid, ctype, operation_id);
858             }
859             if (connection->state == AVCTP_W2_SEND_RELEASE_COMMAND){
860                 // PRESS response
861                 request_pass_through_release_control_cmd(connection);
862             }
863             break;
864         }
865         default:
866             break;
867     }
868 
869     // trigger pending notification reqistrations
870     if ((connection->state == AVCTP_CONNECTION_OPENED) && connection->notifications_to_register){
871         avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
872     }
873 }
874 
875 static void avrcp_controller_handle_can_send_now(avrcp_connection_t * connection){
876     int i;
877     switch (connection->state){
878         case AVCTP_W2_SEND_PRESS_COMMAND:
879             connection->state = AVCTP_W2_RECEIVE_PRESS_RESPONSE;
880             avrcp_send_cmd(connection, AVRCP_SINGLE_PACKET);
881             break;
882         case AVCTP_W2_SEND_COMMAND:
883         case AVCTP_W2_SEND_RELEASE_COMMAND:
884             connection->state = AVCTP_W2_RECEIVE_RESPONSE;
885             avrcp_send_cmd(connection, AVRCP_SINGLE_PACKET);
886             break;
887         case AVCTP_CONNECTION_OPENED:
888             if (connection->notifications_to_register != 0){
889                 for (i = 1; i <= AVRCP_NOTIFICATION_EVENT_VOLUME_CHANGED; i++){
890                     if (connection->notifications_to_register & (1<<i)){
891                         connection->notifications_to_register &= ~ (1 << i);
892                         avrcp_prepare_notification(connection, (avrcp_notification_event_id_t) i);
893                         connection->state = AVCTP_W2_RECEIVE_RESPONSE;
894                         avrcp_send_cmd(connection, AVRCP_SINGLE_PACKET);
895                         return;
896                     }
897                 }
898             }
899             return;
900         case AVCTP_W2_SEND_FRAGMENTED_COMMAND:
901             if (connection->cmd_operands_fragmented_pos == 0){
902                  avrcp_send_cmd(connection, AVRCP_START_PACKET);
903                  avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
904             } else {
905                 if ((connection->cmd_operands_fragmented_len - connection->cmd_operands_fragmented_pos) > avrcp_get_max_payload_size_for_packet_type(AVRCP_CONTINUE_PACKET)){
906                      avrcp_send_cmd(connection, AVRCP_CONTINUE_PACKET);
907                      avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
908                  } else {
909                     connection->state = AVCTP_W2_RECEIVE_RESPONSE;
910                     avrcp_send_cmd(connection, AVRCP_END_PACKET);
911                  }
912             }
913         default:
914             return;
915     }
916 }
917 
918 static void avrcp_controller_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
919     avrcp_connection_t * connection;
920 
921     switch (packet_type) {
922         case L2CAP_DATA_PACKET:
923             connection = get_avrcp_connection_for_l2cap_signaling_cid_for_role(AVRCP_CONTROLLER, channel);
924             avrcp_handle_l2cap_data_packet_for_signaling_connection(connection, packet, size);
925             break;
926 
927         case HCI_EVENT_PACKET:
928             switch (hci_event_packet_get_type(packet)){
929                 case L2CAP_EVENT_CAN_SEND_NOW:
930                     connection = get_avrcp_connection_for_l2cap_signaling_cid_for_role(AVRCP_CONTROLLER, channel);
931                     avrcp_controller_handle_can_send_now(connection);
932                     break;
933             default:
934                 break;
935         }
936         default:
937             break;
938     }
939 }
940 
941 void avrcp_controller_init(void){
942     avrcp_controller_context.role = AVRCP_CONTROLLER;
943     avrcp_controller_context.packet_handler = avrcp_controller_packet_handler;
944     avrcp_register_controller_packet_handler(&avrcp_controller_packet_handler);
945 }
946 
947 void avrcp_controller_register_packet_handler(btstack_packet_handler_t callback){
948     btstack_assert(callback != NULL);
949     avrcp_controller_context.avrcp_callback = callback;
950 }
951 
952 uint8_t avrcp_controller_unit_info(uint16_t avrcp_cid){
953     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
954     if (!connection){
955         log_error("avrcp_unit_info: could not find a connection.");
956         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
957     }
958     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
959     connection->state = AVCTP_W2_SEND_COMMAND;
960 
961     connection->transaction_label++;
962     connection->command_opcode = AVRCP_CMD_OPCODE_UNIT_INFO;
963     connection->command_type = AVRCP_CTYPE_STATUS;
964     connection->subunit_type = AVRCP_SUBUNIT_TYPE_UNIT; //vendor unique
965     connection->subunit_id =   AVRCP_SUBUNIT_ID_IGNORE;
966     memset(connection->cmd_operands, 0xFF, connection->cmd_operands_length);
967     connection->cmd_operands_length = 5;
968     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
969     return ERROR_CODE_SUCCESS;
970 }
971 
972 uint8_t avrcp_controller_subunit_info(uint16_t avrcp_cid){
973     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
974     if (!connection){
975         log_error("avrcp_unit_info: could not find a connection.");
976         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
977     }
978     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
979     connection->state = AVCTP_W2_SEND_COMMAND;
980 
981     connection->transaction_label++;
982     connection->command_opcode = AVRCP_CMD_OPCODE_SUBUNIT_INFO;
983     connection->command_type = AVRCP_CTYPE_STATUS;
984     connection->subunit_type = AVRCP_SUBUNIT_TYPE_UNIT; //vendor unique
985     connection->subunit_id =   AVRCP_SUBUNIT_ID_IGNORE;
986     memset(connection->cmd_operands, 0xFF, connection->cmd_operands_length);
987     connection->cmd_operands[0] = 7; // page: 0, extention_code: 7
988     connection->cmd_operands_length = 5;
989     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
990     return ERROR_CODE_SUCCESS;
991 }
992 
993 static uint8_t avrcp_controller_get_capabilities(uint16_t avrcp_cid, uint8_t capability_id){
994     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
995     if (!connection){
996         log_error("avrcp_get_capabilities: could not find a connection.");
997         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
998     }
999     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1000     connection->state = AVCTP_W2_SEND_COMMAND;
1001 
1002     connection->transaction_label++;
1003     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1004     connection->command_type = AVRCP_CTYPE_STATUS;
1005     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1006     connection->subunit_id = AVRCP_SUBUNIT_ID;
1007     big_endian_store_24(connection->cmd_operands, 0, BT_SIG_COMPANY_ID);
1008     connection->cmd_operands[3] = AVRCP_PDU_ID_GET_CAPABILITIES; // PDU ID
1009     connection->cmd_operands[4] = 0;
1010     big_endian_store_16(connection->cmd_operands, 5, 1); // parameter length
1011     connection->cmd_operands[7] = capability_id;                  // capability ID
1012     connection->cmd_operands_length = 8;
1013     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1014     return ERROR_CODE_SUCCESS;
1015 }
1016 
1017 uint8_t avrcp_controller_get_supported_company_ids(uint16_t avrcp_cid){
1018     return avrcp_controller_get_capabilities(avrcp_cid, AVRCP_CAPABILITY_ID_COMPANY);
1019 }
1020 
1021 uint8_t avrcp_controller_get_supported_events(uint16_t avrcp_cid){
1022     return avrcp_controller_get_capabilities(avrcp_cid, AVRCP_CAPABILITY_ID_EVENT);
1023 }
1024 
1025 
1026 uint8_t avrcp_controller_play(uint16_t avrcp_cid){
1027     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PLAY, 0);
1028 }
1029 
1030 uint8_t avrcp_controller_stop(uint16_t avrcp_cid){
1031     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_STOP, 0);
1032 }
1033 
1034 uint8_t avrcp_controller_pause(uint16_t avrcp_cid){
1035     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PAUSE, 0);
1036 }
1037 
1038 uint8_t avrcp_controller_forward(uint16_t avrcp_cid){
1039     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FORWARD, 0);
1040 }
1041 
1042 uint8_t avrcp_controller_backward(uint16_t avrcp_cid){
1043     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_BACKWARD, 0);
1044 }
1045 
1046 uint8_t avrcp_controller_volume_up(uint16_t avrcp_cid){
1047     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_UP, 0);
1048 }
1049 
1050 uint8_t avrcp_controller_volume_down(uint16_t avrcp_cid){
1051     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_DOWN, 0);
1052 }
1053 
1054 uint8_t avrcp_controller_mute(uint16_t avrcp_cid){
1055     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_MUTE, 0);
1056 }
1057 
1058 uint8_t avrcp_controller_skip(uint16_t avrcp_cid){
1059     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_SKIP, 0);
1060 }
1061 
1062 uint8_t avrcp_controller_fast_forward(uint16_t avrcp_cid){
1063     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FAST_FORWARD, 0);
1064 }
1065 
1066 uint8_t avrcp_controller_rewind(uint16_t avrcp_cid){
1067     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_REWIND, 0);
1068 }
1069 
1070 
1071 /* start cmds */
1072 
1073 uint8_t avrcp_controller_release_press_and_hold_cmd(uint16_t avrcp_cid){
1074     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1075     if (!connection){
1076         log_error("avrcp_stop_play: could not find a connection.");
1077         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1078     }
1079     if (connection->state != AVCTP_W4_STOP) return ERROR_CODE_COMMAND_DISALLOWED;
1080     return request_pass_through_release_control_cmd(connection);
1081 }
1082 
1083 uint8_t avrcp_controller_press_and_hold_play(uint16_t avrcp_cid){
1084     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PLAY, 0);
1085 }
1086 uint8_t avrcp_controller_press_and_hold_stop(uint16_t avrcp_cid){
1087     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_STOP, 0);
1088 }
1089 uint8_t avrcp_controller_press_and_hold_pause(uint16_t avrcp_cid){
1090     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PAUSE, 0);
1091 }
1092 uint8_t avrcp_controller_press_and_hold_forward(uint16_t avrcp_cid){
1093     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FORWARD, 0);
1094 }
1095 uint8_t avrcp_controller_press_and_hold_backward(uint16_t avrcp_cid){
1096     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_BACKWARD, 0);
1097 }
1098 uint8_t avrcp_controller_press_and_hold_fast_forward(uint16_t avrcp_cid){
1099     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FAST_FORWARD, 0);
1100 }
1101 uint8_t avrcp_controller_press_and_hold_rewind(uint16_t avrcp_cid){
1102     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_REWIND, 0);
1103 }
1104 uint8_t avrcp_controller_press_and_hold_volume_up(uint16_t avrcp_cid){
1105     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_UP, 0);
1106 }
1107 uint8_t avrcp_controller_press_and_hold_volume_down(uint16_t avrcp_cid){
1108     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_DOWN, 0);
1109 }
1110 uint8_t avrcp_controller_press_and_hold_mute(uint16_t avrcp_cid){
1111     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_MUTE, 0);
1112 }
1113 
1114 
1115 /* stop continuous cmds */
1116 
1117 uint8_t avrcp_controller_get_play_status(uint16_t avrcp_cid){
1118     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1119     if (!connection){
1120         log_error("avrcp_get_play_status: could not find a connection.");
1121         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1122     }
1123     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1124     connection->state = AVCTP_W2_SEND_COMMAND;
1125     connection->transaction_label++;
1126     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1127     connection->command_type = AVRCP_CTYPE_STATUS;
1128     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1129     connection->subunit_id = AVRCP_SUBUNIT_ID;
1130     big_endian_store_24(connection->cmd_operands, 0, BT_SIG_COMPANY_ID);
1131     connection->cmd_operands[3] = AVRCP_PDU_ID_GET_PLAY_STATUS;
1132     connection->cmd_operands[4] = 0;                     // reserved(upper 6) | packet_type -> 0
1133     big_endian_store_16(connection->cmd_operands, 5, 0); // parameter length
1134     connection->cmd_operands_length = 7;
1135     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1136     return ERROR_CODE_SUCCESS;
1137 }
1138 
1139 uint8_t avrcp_controller_enable_notification(uint16_t avrcp_cid, avrcp_notification_event_id_t event_id){
1140     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1141     if (!connection){
1142         log_error("avrcp_get_play_status: could not find a connection.");
1143         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1144     }
1145     avrcp_register_notification(connection, event_id);
1146     return ERROR_CODE_SUCCESS;
1147 }
1148 
1149 uint8_t avrcp_controller_disable_notification(uint16_t avrcp_cid, avrcp_notification_event_id_t event_id){
1150     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1151     if (!connection){
1152         log_error("avrcp_get_play_status: could not find a connection.");
1153         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1154     }
1155     connection->notifications_to_deregister |= (1 << event_id);
1156     return ERROR_CODE_SUCCESS;
1157 }
1158 
1159 uint8_t avrcp_controller_set_addressed_player(uint16_t avrcp_cid, uint16_t addressed_player_id){
1160     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1161     if (!connection){
1162         log_error("avrcp_get_capabilities: could not find a connection.");
1163         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1164     }
1165     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1166     connection->state = AVCTP_W2_SEND_COMMAND;
1167 
1168     connection->transaction_label++;
1169     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1170     connection->command_type = AVRCP_CTYPE_CONTROL;
1171     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1172     connection->subunit_id = AVRCP_SUBUNIT_ID;
1173     int pos = 0;
1174     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1175     pos += 3;
1176     connection->cmd_operands[pos++] = AVRCP_PDU_ID_SET_ADDRESSED_PLAYER; // PDU ID
1177     connection->cmd_operands[pos++] = 0;
1178 
1179     // Parameter Length
1180     big_endian_store_16(connection->cmd_operands, pos, 2);
1181     pos += 2;
1182 
1183     big_endian_store_16(connection->cmd_operands, pos, addressed_player_id);
1184     pos += 2;
1185 
1186     connection->cmd_operands_length = pos;
1187     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1188     return ERROR_CODE_SUCCESS;
1189 }
1190 
1191 uint8_t avrcp_controller_get_now_playing_info(uint16_t avrcp_cid){
1192     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1193     if (!connection){
1194         log_error("avrcp_get_capabilities: could not find a connection.");
1195         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1196     }
1197     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1198     connection->state = AVCTP_W2_SEND_COMMAND;
1199 
1200     connection->transaction_label++;
1201     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1202     connection->command_type = AVRCP_CTYPE_STATUS;
1203     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1204     connection->subunit_id = AVRCP_SUBUNIT_ID;
1205     int pos = 0;
1206     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1207     pos += 3;
1208     connection->cmd_operands[pos++] = AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES; // PDU ID
1209     connection->cmd_operands[pos++] = 0;
1210 
1211     // Parameter Length
1212     big_endian_store_16(connection->cmd_operands, pos, 9);
1213     pos += 2;
1214 
1215     // write 8 bytes value
1216     memset(connection->cmd_operands + pos, 0, 8); // identifier: PLAYING
1217     pos += 8;
1218 
1219     connection->cmd_operands[pos++] = 0; // attribute count, if 0 get all attributes
1220     // every attribute is 4 bytes long
1221 
1222     connection->cmd_operands_length = pos;
1223     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1224     return ERROR_CODE_SUCCESS;
1225 }
1226 
1227 uint8_t avrcp_controller_set_absolute_volume(uint16_t avrcp_cid, uint8_t volume){
1228      avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1229     if (!connection){
1230         log_error("avrcp_get_capabilities: could not find a connection.");
1231         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1232     }
1233     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1234     connection->state = AVCTP_W2_SEND_COMMAND;
1235 
1236     connection->transaction_label++;
1237     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1238     connection->command_type = AVRCP_CTYPE_CONTROL;
1239     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1240     connection->subunit_id = AVRCP_SUBUNIT_ID;
1241     int pos = 0;
1242     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1243     pos += 3;
1244     connection->cmd_operands[pos++] = AVRCP_PDU_ID_SET_ABSOLUTE_VOLUME; // PDU ID
1245     connection->cmd_operands[pos++] = 0;
1246 
1247     // Parameter Length
1248     big_endian_store_16(connection->cmd_operands, pos, 1);
1249     pos += 2;
1250     connection->cmd_operands[pos++] = volume;
1251 
1252     connection->cmd_operands_length = pos;
1253     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1254     return ERROR_CODE_SUCCESS;
1255 }
1256 
1257 uint8_t avrcp_controller_query_shuffle_and_repeat_modes(uint16_t avrcp_cid){
1258     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1259     if (!connection){
1260         log_error("avrcp_get_capabilities: could not find a connection.");
1261         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1262     }
1263     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1264     connection->state = AVCTP_W2_SEND_COMMAND;
1265 
1266     connection->transaction_label++;
1267     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1268     connection->command_type = AVRCP_CTYPE_STATUS;
1269     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1270     connection->subunit_id = AVRCP_SUBUNIT_ID;
1271     big_endian_store_24(connection->cmd_operands, 0, BT_SIG_COMPANY_ID);
1272     connection->cmd_operands[3] = AVRCP_PDU_ID_GetCurrentPlayerApplicationSettingValue; // PDU ID
1273     connection->cmd_operands[4] = 0;
1274     big_endian_store_16(connection->cmd_operands, 5, 5); // parameter length
1275     connection->cmd_operands[7] = 4;                     // NumPlayerApplicationSettingAttributeID
1276     // PlayerApplicationSettingAttributeID1 AVRCP Spec, Appendix F, 133
1277     connection->cmd_operands[8]  = 0x01;    // equalizer  (1-OFF, 2-ON)
1278     connection->cmd_operands[9]  = 0x02;    // repeat     (1-off, 2-single track, 3-all tracks, 4-group repeat)
1279     connection->cmd_operands[10] = 0x03;    // shuffle    (1-off, 2-all tracks, 3-group shuffle)
1280     connection->cmd_operands[11] = 0x04;    // scan       (1-off, 2-all tracks, 3-group scan)
1281     connection->cmd_operands_length = 12;
1282     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1283     return ERROR_CODE_SUCCESS;
1284 }
1285 
1286 static uint8_t avrcp_controller_set_current_player_application_setting_value(uint16_t avrcp_cid, uint8_t attr_id, uint8_t attr_value){
1287     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1288     if (!connection){
1289         log_error("avrcp_get_capabilities: could not find a connection.");
1290         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1291     }
1292     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1293     connection->state = AVCTP_W2_SEND_COMMAND;
1294 
1295     connection->transaction_label++;
1296     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1297     connection->command_type = AVRCP_CTYPE_CONTROL;
1298     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1299     connection->subunit_id = AVRCP_SUBUNIT_ID;
1300     int pos = 0;
1301     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1302     pos += 3;
1303     connection->cmd_operands[pos++] = AVRCP_PDU_ID_SetPlayerApplicationSettingValue; // PDU ID
1304     connection->cmd_operands[pos++] = 0;
1305     // Parameter Length
1306     big_endian_store_16(connection->cmd_operands, pos, 3);
1307     pos += 2;
1308     connection->cmd_operands[pos++] = 2;
1309     connection->cmd_operands_length = pos;
1310     connection->cmd_operands[pos++]  = attr_id;
1311     connection->cmd_operands[pos++]  = attr_value;
1312     connection->cmd_operands_length = pos;
1313     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1314     return ERROR_CODE_SUCCESS;
1315 }
1316 
1317 uint8_t avrcp_controller_set_shuffle_mode(uint16_t avrcp_cid, avrcp_shuffle_mode_t mode){
1318     if ((mode < AVRCP_SHUFFLE_MODE_OFF) || (mode > AVRCP_SHUFFLE_MODE_GROUP)) return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
1319     return avrcp_controller_set_current_player_application_setting_value(avrcp_cid, 0x03, mode);
1320 }
1321 
1322 uint8_t avrcp_controller_set_repeat_mode(uint16_t avrcp_cid, avrcp_repeat_mode_t mode){
1323     if ((mode < AVRCP_REPEAT_MODE_OFF) || (mode > AVRCP_REPEAT_MODE_GROUP)) return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
1324     return avrcp_controller_set_current_player_application_setting_value(avrcp_cid, 0x02, mode);
1325 }
1326 
1327 uint8_t avrcp_controller_play_item_for_scope(uint16_t avrcp_cid, uint8_t * uid, uint16_t uid_counter, avrcp_browsing_scope_t scope){
1328     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1329     if (!connection){
1330         log_error("Could not find a connection with cid 0%02x.", avrcp_cid);
1331         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1332     }
1333     if (connection->state != AVCTP_CONNECTION_OPENED){
1334         log_error("Connection in wrong state, expected %d, received %d", AVCTP_CONNECTION_OPENED, connection->state);
1335         return ERROR_CODE_COMMAND_DISALLOWED;
1336     }
1337     connection->state = AVCTP_W2_SEND_COMMAND;
1338 
1339     connection->transaction_label++;
1340     connection->command_type = AVRCP_CTYPE_CONTROL;
1341     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1342     connection->subunit_id = AVRCP_SUBUNIT_ID;
1343     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1344     int pos = 0;
1345     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1346     pos += 3;
1347     connection->cmd_operands[pos++] = AVRCP_PDU_ID_PLAY_ITEM; // PDU ID
1348     // reserved
1349     connection->cmd_operands[pos++] = 0;
1350     // Parameter Length
1351     big_endian_store_16(connection->cmd_operands, pos, 11);
1352     pos += 2;
1353     connection->cmd_operands[pos++]  = scope;
1354     memset(&connection->cmd_operands[pos], 0, 8);
1355     if (uid){
1356         (void)memcpy(&connection->cmd_operands[pos], uid, 8);
1357     }
1358     pos += 8;
1359     big_endian_store_16(connection->cmd_operands, pos, uid_counter);
1360     pos += 2;
1361     connection->cmd_operands_length = pos;
1362 
1363     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1364     return ERROR_CODE_SUCCESS;
1365 }
1366 
1367 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){
1368     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1369     if (!connection){
1370         log_error("Could not find a connection with cid 0%02x.", avrcp_cid);
1371         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1372     }
1373     if (connection->state != AVCTP_CONNECTION_OPENED){
1374         log_error("Connection in wrong state, expected %d, received %d", AVCTP_CONNECTION_OPENED, connection->state);
1375         return ERROR_CODE_COMMAND_DISALLOWED;
1376     }
1377     connection->state = AVCTP_W2_SEND_COMMAND;
1378 
1379     connection->transaction_label++;
1380     connection->command_type = AVRCP_CTYPE_CONTROL;
1381     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1382     connection->subunit_id = AVRCP_SUBUNIT_ID;
1383     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1384     int pos = 0;
1385     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1386     pos += 3;
1387     connection->cmd_operands[pos++] = AVRCP_PDU_ID_ADD_TO_NOW_PLAYING; // PDU ID
1388     // reserved
1389     connection->cmd_operands[pos++] = 0;
1390     // Parameter Length
1391     big_endian_store_16(connection->cmd_operands, pos, 11);
1392     pos += 2;
1393     connection->cmd_operands[pos++]  = scope;
1394     memset(&connection->cmd_operands[pos], 0, 8);
1395     if (uid){
1396         (void)memcpy(&connection->cmd_operands[pos], uid, 8);
1397     }
1398     pos += 8;
1399     big_endian_store_16(connection->cmd_operands, pos, uid_counter);
1400     pos += 2;
1401     connection->cmd_operands_length = pos;
1402 
1403     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1404     return ERROR_CODE_SUCCESS;
1405 }
1406 
1407 uint8_t avrcp_controller_set_max_num_fragments(uint16_t avrcp_cid, uint8_t max_num_fragments){
1408     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1409     if (!connection){
1410         log_error("avrcp_controller_play_item: could not find a connection.");
1411         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1412     }
1413     connection->max_num_fragments = max_num_fragments;
1414     return ERROR_CODE_SUCCESS;
1415 }
1416 
1417 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){
1418     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1419     if (!connection){
1420         log_error("avrcp_controller_play_item: could not find a connection.");
1421         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1422     }
1423 
1424     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1425     connection->state = AVCTP_W2_SEND_FRAGMENTED_COMMAND;
1426 
1427     connection->transaction_label++;
1428     connection->command_opcode = command_opcode;
1429     connection->command_type = command_type;
1430     connection->subunit_type = subunit_type;
1431     connection->subunit_id = subunit_id;
1432     connection->cmd_operands_fragmented_buffer = command_buffer;
1433     connection->cmd_operands_fragmented_pos = 0;
1434     connection->cmd_operands_fragmented_len = command_len;
1435 
1436     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1437     return ERROR_CODE_SUCCESS;
1438 }
1439