xref: /btstack/src/classic/avrcp_controller.c (revision 1884f13fb9884b15dacdfc04d9536827c4949e99)
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 void avrcp_controller_create_sdp_record(uint8_t * service, uint32_t service_record_handle, uint8_t browsing, uint16_t supported_features, const char * service_name, const char * service_provider_name){
54     avrcp_create_sdp_record(1, service, service_record_handle, browsing, supported_features, service_name, service_provider_name);
55 }
56 
57 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){
58     if (!callback) return;
59     uint8_t event[8];
60     int pos = 0;
61     event[pos++] = HCI_EVENT_AVRCP_META;
62     event[pos++] = sizeof(event) - 2;
63     event[pos++] = AVRCP_SUBEVENT_SHUFFLE_AND_REPEAT_MODE;
64     little_endian_store_16(event, pos, avrcp_cid);
65     pos += 2;
66     event[pos++] = ctype;
67     event[pos++] = repeat_mode;
68     event[pos++] = shuffle_mode;
69     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
70 }
71 
72 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){
73     if (!callback) return;
74     uint8_t event[7];
75     int pos = 0;
76     event[pos++] = HCI_EVENT_AVRCP_META;
77     event[pos++] = sizeof(event) - 2;
78     event[pos++] = subevent;
79     little_endian_store_16(event, pos, avrcp_cid);
80     pos += 2;
81     event[pos++] = ctype;
82     event[pos++] = operation_id;
83     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
84 }
85 
86 static void avrcp_press_and_hold_timeout_handler(btstack_timer_source_t * timer){
87     UNUSED(timer);
88     avrcp_connection_t * connection = btstack_run_loop_get_timer_context(timer);
89     btstack_run_loop_set_timer(&connection->press_and_hold_cmd_timer, 2000); // 2 seconds timeout
90     btstack_run_loop_add_timer(&connection->press_and_hold_cmd_timer);
91     connection->state = AVCTP_W2_SEND_PRESS_COMMAND;
92     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
93 }
94 
95 static void avrcp_press_and_hold_timer_start(avrcp_connection_t * connection){
96     btstack_run_loop_remove_timer(&connection->press_and_hold_cmd_timer);
97     btstack_run_loop_set_timer_handler(&connection->press_and_hold_cmd_timer, avrcp_press_and_hold_timeout_handler);
98     btstack_run_loop_set_timer_context(&connection->press_and_hold_cmd_timer, connection);
99     btstack_run_loop_set_timer(&connection->press_and_hold_cmd_timer, 2000); // 2 seconds timeout
100     btstack_run_loop_add_timer(&connection->press_and_hold_cmd_timer);
101 }
102 
103 static void avrcp_press_and_hold_timer_stop(avrcp_connection_t * connection){
104     connection->continuous_fast_forward_cmd = 0;
105     btstack_run_loop_remove_timer(&connection->press_and_hold_cmd_timer);
106 }
107 
108 static uint8_t request_pass_through_release_control_cmd(avrcp_connection_t * connection){
109     connection->state = AVCTP_W2_SEND_RELEASE_COMMAND;
110     if (connection->continuous_fast_forward_cmd){
111         avrcp_press_and_hold_timer_stop(connection);
112     }
113     connection->cmd_operands[0] = 0x80 | connection->cmd_operands[0];
114     connection->transaction_label++;
115     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
116     return ERROR_CODE_SUCCESS;
117 }
118 
119 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, avrcp_context_t * context){
120     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, context);
121     if (!connection){
122         log_error("avrcp: could not find a connection.");
123         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
124     }
125     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
126     connection->state = AVCTP_W2_SEND_PRESS_COMMAND;
127     connection->command_opcode =  AVRCP_CMD_OPCODE_PASS_THROUGH;
128     connection->command_type = AVRCP_CTYPE_CONTROL;
129     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
130     connection->subunit_id =   AVRCP_SUBUNIT_ID;
131     connection->cmd_operands_length = 0;
132 
133     connection->continuous_fast_forward_cmd = continuous_fast_forward_cmd;
134     connection->cmd_operands_length = 2;
135     connection->cmd_operands[0] = opid;
136     if (playback_speed > 0){
137         connection->cmd_operands[2] = playback_speed;
138         connection->cmd_operands_length++;
139     }
140     connection->cmd_operands[1] = connection->cmd_operands_length - 2;
141 
142     if (connection->continuous_fast_forward_cmd){
143         avrcp_press_and_hold_timer_start(connection);
144     }
145 
146     connection->transaction_label++;
147     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
148     return ERROR_CODE_SUCCESS;
149 }
150 
151 static uint8_t request_single_pass_through_press_control_cmd(uint16_t avrcp_cid, avrcp_operation_id_t opid, uint16_t playback_speed){
152     return request_pass_through_press_control_cmd(avrcp_cid, opid, playback_speed, 0, &avrcp_controller_context);
153 }
154 
155 static uint8_t request_continuous_pass_through_press_control_cmd(uint16_t avrcp_cid, avrcp_operation_id_t opid, uint16_t playback_speed){
156     return request_pass_through_press_control_cmd(avrcp_cid, opid, playback_speed, 1, &avrcp_controller_context);
157 }
158 
159 #define AVRCP_CMD_BUFFER_SIZE 30
160 static uint16_t avrcp_get_max_payload_size_for_packet_type(avrcp_packet_type_t packet_type){
161     switch (packet_type){
162         case AVRCP_SINGLE_PACKET:
163             return AVRCP_CMD_BUFFER_SIZE - 3;
164         case AVRCP_START_PACKET:
165             return AVRCP_CMD_BUFFER_SIZE - 4;
166         case AVRCP_CONTINUE_PACKET:
167         case AVRCP_END_PACKET:
168             return AVRCP_CMD_BUFFER_SIZE - 1;
169     }
170     return 0;
171 }
172 
173 static int avrcp_send_cmd(avrcp_connection_t * connection, avrcp_packet_type_t packet_type){
174     uint8_t command[AVRCP_CMD_BUFFER_SIZE];
175     int pos = 0;
176     uint16_t max_bytes = sizeof(command) - 1;
177 
178     // transport header
179     // Transaction label | Packet_type | C/R | IPID (1 == invalid profile identifier)
180     command[pos++] = (connection->transaction_label << 4) | (packet_type << 2) | (AVRCP_COMMAND_FRAME << 1) | 0;
181 
182     if (packet_type == AVRCP_START_PACKET){
183         // num packets: (3 bytes overhead (PID, num packets) + command) / (MTU - transport header)
184         command[pos++] = ((connection->cmd_operands_fragmented_len + 3 - 1) / (AVRCP_CMD_BUFFER_SIZE - 1)) + 1;
185         max_bytes -= 3;
186     }
187 
188     if (packet_type == AVRCP_SINGLE_PACKET || packet_type == AVRCP_START_PACKET){
189         // Profile IDentifier (PID)
190         command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL >> 8;
191         command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL & 0x00FF;
192 
193         // command_type
194         command[pos++] = connection->command_type;
195         // subunit_type | subunit ID
196         command[pos++] = (connection->subunit_type << 3) | connection->subunit_id;
197         // opcode
198         command[pos++] = (uint8_t)connection->command_opcode;
199     }
200 
201     if (packet_type == AVRCP_SINGLE_PACKET){
202         // operands
203         memcpy(command+pos, connection->cmd_operands, connection->cmd_operands_length);
204         pos += connection->cmd_operands_length;
205     } else {
206         uint16_t bytes_to_copy = btstack_min(connection->cmd_operands_fragmented_len-connection->cmd_operands_fragmented_pos, max_bytes);
207         memcpy(command+pos, &connection->cmd_operands_fragmented_buffer[connection->cmd_operands_fragmented_pos], bytes_to_copy);
208         pos += bytes_to_copy;
209         connection->cmd_operands_fragmented_pos += bytes_to_copy;
210     }
211 
212     return l2cap_send(connection->l2cap_signaling_cid, command, pos);
213 }
214 
215 static int avrcp_register_notification(avrcp_connection_t * connection, avrcp_notification_event_id_t event_id){
216     if (connection->notifications_to_deregister & (1 << event_id)) return 0;
217     if (connection->notifications_enabled & (1 << event_id)) return 0;
218     if (connection->notifications_to_register & (1 << event_id)) return 0;
219     connection->notifications_to_register |= (1 << event_id);
220     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
221     return 1;
222 }
223 
224 static void avrcp_prepare_notification(avrcp_connection_t * connection, avrcp_notification_event_id_t event_id){
225     connection->transaction_label++;
226     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
227     connection->command_type = AVRCP_CTYPE_NOTIFY;
228     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
229     connection->subunit_id = AVRCP_SUBUNIT_ID;
230     int pos = 0;
231     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
232     pos += 3;
233     connection->cmd_operands[pos++] = AVRCP_PDU_ID_REGISTER_NOTIFICATION;
234     connection->cmd_operands[pos++] = 0;                     // reserved(upper 6) | packet_type -> 0
235     big_endian_store_16(connection->cmd_operands, pos, 5);     // parameter length
236     pos += 2;
237     connection->cmd_operands[pos++] = event_id;
238     big_endian_store_32(connection->cmd_operands, pos, 0);
239     pos += 4;
240     connection->cmd_operands_length = pos;
241     // AVRCP_SPEC_V14.pdf 166
242     // answer page 61
243 }
244 
245 
246 static void avrcp_parser_reset(avrcp_connection_t * connection){
247     connection->list_offset = 0;
248     connection->num_attributes = 0;
249     connection->num_parsed_attributes = 0;
250     connection->parser_attribute_header_pos = 0;
251     connection->num_received_fragments = 0;
252     connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_HEADER;
253 }
254 
255 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){
256     uint8_t event[7];
257     int pos = 0;
258     event[pos++] = HCI_EVENT_AVRCP_META;
259     event[pos++] = sizeof(event) - 2;
260     event[pos++] = AVRCP_SUBEVENT_NOW_PLAYING_INFO_DONE;
261     little_endian_store_16(event, pos, avrcp_cid);
262     pos += 2;
263     event[pos++] = ctype;
264     event[pos++] = status;
265     // printf_hexdump(event, pos);
266     (*callback)(HCI_EVENT_PACKET, 0, event, pos);
267 }
268 
269 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){
270     uint8_t event[HCI_EVENT_BUFFER_SIZE];
271     int pos = 0;
272     event[pos++] = HCI_EVENT_AVRCP_META;
273     // reserve one byte for subevent type and data len
274     int data_len_pos = pos;
275     pos++;
276     int subevent_type_pos = pos;
277     pos++;
278     little_endian_store_16(event, pos, avrcp_cid);
279     pos += 2;
280     event[pos++] = ctype;
281 
282     switch (attr_id){
283         case AVRCP_MEDIA_ATTR_TITLE:
284             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TITLE_INFO;
285             event[pos++] = value_len;
286             memcpy(event+pos, value, value_len);
287             break;
288         case AVRCP_MEDIA_ATTR_ARTIST:
289             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_ARTIST_INFO;
290             event[pos++] = value_len;
291             memcpy(event+pos, value, value_len);
292             break;
293         case AVRCP_MEDIA_ATTR_ALBUM:
294             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_ALBUM_INFO;
295             event[pos++] = value_len;
296             memcpy(event+pos, value, value_len);
297             break;
298         case AVRCP_MEDIA_ATTR_GENRE:
299             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_GENRE_INFO;
300             event[pos++] = value_len;
301             memcpy(event+pos, value, value_len);
302             break;
303         case AVRCP_MEDIA_ATTR_SONG_LENGTH_MS:
304             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_SONG_LENGTH_MS_INFO;
305             if (value){
306                 little_endian_store_32(event, pos, btstack_atoi((char *)value));
307             } else {
308                 little_endian_store_32(event, pos, 0);
309             }
310             pos += 4;
311             break;
312         case AVRCP_MEDIA_ATTR_TRACK:
313             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TRACK_INFO;
314             if (value){
315                 event[pos++] = btstack_atoi((char *)value);
316             } else {
317                 event[pos++] = 0;
318             }
319             break;
320         case AVRCP_MEDIA_ATTR_TOTAL_NUM_ITEMS:
321             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TOTAL_TRACKS_INFO;
322             if (value){
323                 event[pos++] = btstack_atoi((char *)value);
324             } else {
325                 event[pos++] = 0;
326             }
327             break;
328         default:
329             break;
330     }
331     event[data_len_pos] = pos - 2;
332     // printf("Send attribute 0x%02x, len %u\n", attr_id, value_len);
333     // printf_hexdump(value, value_len);
334     (*callback)(HCI_EVENT_PACKET, 0, event, pos);
335 }
336 
337 static void avrcp_parser_process_byte(uint8_t byte, avrcp_connection_t * connection, avrcp_command_type_t ctype){
338     uint16_t attribute_total_value_len;
339     uint32_t attribute_id;
340     // printf("avrcp_parser_process_byte: %02x, state %02x\n", byte, connection->parser_state);
341     switch(connection->parser_state){
342         case AVRCP_PARSER_GET_ATTRIBUTE_HEADER:
343             connection->parser_attribute_header[connection->parser_attribute_header_pos++] = byte;
344             connection->list_offset++;
345 
346             if (connection->parser_attribute_header_pos < AVRCP_ATTRIBUTE_HEADER_LEN) return;
347 
348             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
349             connection->attribute_value_len = btstack_min(attribute_total_value_len, AVRCP_MAX_ATTRIBUTTE_SIZE);
350             if (connection->attribute_value_len > 0){
351                 // get ready for attribute value
352                 connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_VALUE;
353                 return;
354             }
355 
356             // emit empty attribute
357             attribute_id = big_endian_read_32(connection->parser_attribute_header, 0);
358             avrcp_controller_emit_now_playing_info_event(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, attribute_id, connection->attribute_value, connection->attribute_value_len);
359 
360             // done, see below
361             break;
362 
363         case AVRCP_PARSER_GET_ATTRIBUTE_VALUE:
364             connection->attribute_value[connection->attribute_value_offset++] = byte;
365             connection->list_offset++;
366 
367             if (connection->attribute_value_offset < connection->attribute_value_len) return;
368 
369             // emit (potentially partial) attribute
370             attribute_id = big_endian_read_32(connection->parser_attribute_header, 0);
371             avrcp_controller_emit_now_playing_info_event(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, attribute_id, connection->attribute_value, connection->attribute_value_len);
372 
373             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
374             if (connection->attribute_value_offset < attribute_total_value_len){
375                 // ignore rest of attribute
376                 connection->parser_state = AVRCP_PARSER_IGNORE_REST_OF_ATTRIBUTE_VALUE;
377                 return;
378             }
379 
380             // done, see below
381             break;
382 
383         case AVRCP_PARSER_IGNORE_REST_OF_ATTRIBUTE_VALUE:
384             connection->attribute_value_offset++;
385             connection->list_offset++;
386 
387             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
388             if (connection->attribute_value_offset < attribute_total_value_len) return;
389 
390             // done, see below
391             break;
392 
393         default:
394             return;
395     }
396 
397     // attribute fully read, check if more to come
398     if (connection->list_offset < connection->list_size){
399         // more to come, reset parser
400         connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_HEADER;
401         connection->parser_attribute_header_pos = 0;
402         connection->attribute_value_offset = 0;
403     } else {
404         // fully done
405         avrcp_parser_reset(connection);
406         avrcp_controller_emit_now_playing_info_event_done(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, 0);
407     }
408 }
409 
410 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){
411     int i;
412     for (i=0;i<num_bytes_to_read;i++){
413         avrcp_parser_process_byte(packet[i], connection, ctype);
414     }
415 }
416 
417 static uint8_t avrcp_controller_request_abort_continuation(avrcp_connection_t * connection){
418     connection->state = AVCTP_W2_SEND_COMMAND;
419     connection->transaction_label++;
420     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
421     connection->command_type = AVRCP_CTYPE_CONTROL;
422     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
423     connection->subunit_id = AVRCP_SUBUNIT_ID;
424     int pos = 0;
425     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
426     pos += 3;
427     connection->cmd_operands[pos++] = AVRCP_PDU_ID_REQUEST_ABORT_CONTINUING_RESPONSE; // PDU ID
428     connection->cmd_operands[pos++] = 0;
429     // Parameter Length
430     connection->cmd_operands_length = 8;
431     big_endian_store_16(connection->cmd_operands, pos, 1);
432     pos += 2;
433     connection->cmd_operands[pos++] = AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES;
434     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
435     return ERROR_CODE_SUCCESS;
436 }
437 
438 
439 static uint8_t avrcp_controller_request_continue_response(avrcp_connection_t * connection){
440     connection->state = AVCTP_W2_SEND_COMMAND;
441     connection->transaction_label++;
442     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
443     connection->command_type = AVRCP_CTYPE_CONTROL;
444     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
445     connection->subunit_id = AVRCP_SUBUNIT_ID;
446     int pos = 0;
447     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
448     pos += 3;
449     connection->cmd_operands[pos++] = AVRCP_PDU_ID_REQUEST_CONTINUING_RESPONSE; // PDU ID
450     connection->cmd_operands[pos++] = 0;
451     // Parameter Length
452     connection->cmd_operands_length = 8;
453     big_endian_store_16(connection->cmd_operands, pos, 1);
454     pos += 2;
455     connection->cmd_operands[pos++] = AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES;
456     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
457     return ERROR_CODE_SUCCESS;
458 }
459 
460 static void avrcp_handle_l2cap_data_packet_for_signaling_connection(avrcp_connection_t * connection, uint8_t *packet, uint16_t size){
461     uint8_t operands[20];
462     uint8_t opcode;
463     int     pos = 3;
464     // uint8_t transport_header = packet[0];
465     // uint8_t transaction_label = transport_header >> 4;
466     // uint8_t packet_type = (transport_header & 0x0F) >> 2;
467     // uint8_t frame_type = (transport_header & 0x03) >> 1;
468     // uint8_t ipid = transport_header & 0x01;
469     // uint8_t byte_value = packet[2];
470     // uint16_t pid = (byte_value << 8) | packet[2];
471 
472     avrcp_command_type_t ctype = (avrcp_command_type_t) packet[pos++];
473     uint8_t byte_value = packet[pos++];
474     avrcp_subunit_type_t subunit_type = (avrcp_subunit_type_t) (byte_value >> 3);
475     avrcp_subunit_type_t subunit_id = (avrcp_subunit_type_t)   (byte_value & 0x07);
476     opcode = packet[pos++];
477 
478     // printf("    Transport header 0x%02x (transaction_label %d, packet_type %d, frame_type %d, ipid %d), pid 0x%4x\n",
479     //     transport_header, transaction_label, packet_type, frame_type, ipid, pid);
480     // // printf_hexdump(packet+pos, size-pos);
481 
482     uint8_t pdu_id;
483     uint16_t param_length;
484     switch (avrcp_cmd_opcode(packet,size)){
485         case AVRCP_CMD_OPCODE_SUBUNIT_INFO:{
486             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE) return;
487             connection->state = AVCTP_CONNECTION_OPENED;
488             // operands:
489             memcpy(operands, packet+pos, 5);
490             uint8_t unit_type = operands[1] >> 3;
491             uint8_t max_subunit_ID = operands[1] & 0x07;
492             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);
493             break;
494         }
495         case AVRCP_CMD_OPCODE_UNIT_INFO:{
496             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE) return;
497             connection->state = AVCTP_CONNECTION_OPENED;
498             // operands:
499             memcpy(operands, packet+pos, 5);
500             uint8_t unit_type = operands[1] >> 3;
501             uint8_t unit = operands[1] & 0x07;
502             uint32_t company_id = operands[2] << 16 | operands[3] << 8 | operands[4];
503             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,
504                 ctype, subunit_type, subunit_id, opcode, unit_type, unit, company_id);
505             break;
506         }
507         case AVRCP_CMD_OPCODE_VENDOR_DEPENDENT:
508             if (size - pos < 7) {
509                 log_error("avrcp: wrong packet size");
510                 return;
511             };
512             // operands:
513             memcpy(operands, packet+pos, 7);
514             pos += 7;
515             // uint32_t company_id = operands[0] << 16 | operands[1] << 8 | operands[2];
516             pdu_id = operands[3];
517 
518             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE && pdu_id != AVRCP_PDU_ID_REGISTER_NOTIFICATION){
519                 log_info("AVRCP_CMD_OPCODE_VENDOR_DEPENDENT state %d", connection->state);
520                 return;
521             }
522             connection->state = AVCTP_CONNECTION_OPENED;
523 
524 
525             // uint8_t unit_type = operands[4] >> 3;
526             // uint8_t unit = operands[4] & 0x07;
527             param_length = big_endian_read_16(operands, 5);
528 
529             // printf("    VENDOR DEPENDENT 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%06x\n",
530             //     ctype, subunit_type, subunit_id, opcode, unit_type, unit, company_id );
531 
532             // if (ctype == AVRCP_CTYPE_RESPONSE_INTERIM) return;
533             log_info("        VENDOR DEPENDENT response: pdu id 0x%02x, param_length %d, status %s", pdu_id, param_length, avrcp_ctype2str(ctype));
534             switch (pdu_id){
535                 case AVRCP_PDU_ID_GetCurrentPlayerApplicationSettingValue:{
536                     uint8_t num_attributes = packet[pos++];
537                     int i;
538                     avrcp_repeat_mode_t  repeat_mode =  AVRCP_REPEAT_MODE_INVALID;
539                     avrcp_shuffle_mode_t shuffle_mode = AVRCP_SHUFFLE_MODE_INVALID;
540                     for (i = 0; i < num_attributes; i++){
541                         uint8_t attribute_id    = packet[pos++];
542                         uint8_t value = packet[pos++];
543                         switch (attribute_id){
544                             case 0x02:
545                                 repeat_mode = (avrcp_repeat_mode_t) value;
546                                 break;
547                             case 0x03:
548                                 shuffle_mode = (avrcp_shuffle_mode_t) value;
549                                 break;
550                             default:
551                                 break;
552                         }
553                     }
554                     avrcp_emit_repeat_and_shuffle_mode(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, repeat_mode, shuffle_mode);
555                     break;
556                 }
557                 case AVRCP_PDU_ID_SetPlayerApplicationSettingValue:{
558                     uint8_t event[6];
559                     int offset = 0;
560                     event[offset++] = HCI_EVENT_AVRCP_META;
561                     event[offset++] = sizeof(event) - 2;
562                     event[offset++] = AVRCP_SUBEVENT_PLAYER_APPLICATION_VALUE_RESPONSE;
563                     little_endian_store_16(event, offset, connection->avrcp_cid);
564                     offset += 2;
565                     event[offset++] = ctype;
566                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
567                     break;
568                 }
569                 case AVRCP_PDU_ID_SET_ABSOLUTE_VOLUME:{
570                     uint8_t event[7];
571                     int offset = 0;
572                     event[offset++] = HCI_EVENT_AVRCP_META;
573                     event[offset++] = sizeof(event) - 2;
574                     event[offset++] = AVRCP_SUBEVENT_SET_ABSOLUTE_VOLUME_RESPONSE;
575                     little_endian_store_16(event, offset, connection->avrcp_cid);
576                     offset += 2;
577                     event[offset++] = ctype;
578                     event[offset++] = packet[pos++];
579                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
580                     break;
581                 }
582                 case AVRCP_PDU_ID_GET_CAPABILITIES:{
583                     avrcp_capability_id_t capability_id = (avrcp_capability_id_t) packet[pos++];
584                     uint8_t capability_count = packet[pos++];
585                     int i;
586                     switch (capability_id){
587                         case AVRCP_CAPABILITY_ID_COMPANY:
588                             // log_info("Supported companies %d: ", capability_count);
589                             for (i = 0; i < capability_count; i++){
590                                 uint32_t company_id = big_endian_read_24(packet, pos);
591                                 pos += 3;
592                                 log_info("  0x%06" PRIx32 ", ", company_id);
593                             }
594                             break;
595                         case AVRCP_CAPABILITY_ID_EVENT:
596                             // log_info("Supported events %d: ", capability_count);
597                             for (i = 0; i < capability_count; i++){
598                                 uint8_t event_id = packet[pos++];
599                                 log_info("  0x%02x %s", event_id, avrcp_event2str(event_id));
600                             }
601                             break;
602                     }
603                     break;
604                 }
605                 case AVRCP_PDU_ID_GET_PLAY_STATUS:{
606                     uint32_t song_length = big_endian_read_32(packet, pos);
607                     pos += 4;
608                     uint32_t song_position = big_endian_read_32(packet, pos);
609                     pos += 4;
610                     uint8_t play_status = packet[pos];
611                     // log_info("        GET_PLAY_STATUS length 0x%04X, position 0x%04X, status %s", song_length, song_position, avrcp_play_status2str(play_status));
612 
613                     uint8_t event[15];
614                     int offset = 0;
615                     event[offset++] = HCI_EVENT_AVRCP_META;
616                     event[offset++] = sizeof(event) - 2;
617                     event[offset++] = AVRCP_SUBEVENT_PLAY_STATUS;
618                     little_endian_store_16(event, offset, connection->avrcp_cid);
619                     offset += 2;
620                     event[offset++] = ctype;
621                     little_endian_store_32(event, offset, song_length);
622                     offset += 4;
623                     little_endian_store_32(event, offset, song_position);
624                     offset += 4;
625                     event[offset++] = play_status;
626                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
627                     break;
628                 }
629                 case AVRCP_PDU_ID_REGISTER_NOTIFICATION:{
630                     avrcp_notification_event_id_t  event_id = (avrcp_notification_event_id_t) packet[pos++];
631                     uint16_t event_mask = (1 << event_id);
632                     uint16_t reset_event_mask = ~event_mask;
633                     switch (ctype){
634                         case AVRCP_CTYPE_RESPONSE_INTERIM:
635                             // register as enabled
636                             connection->notifications_enabled |= event_mask;
637                             // printf("INTERIM notifications_enabled 0x%2x, notifications_to_register 0x%2x\n", connection->notifications_enabled,  connection->notifications_to_register);
638                             break;
639                         case AVRCP_CTYPE_RESPONSE_CHANGED_STABLE:
640                             // received change, event is considered deregistered
641                             // we are re-enabling it automatically, if it is not
642                             // explicitly disabled
643                             connection->notifications_enabled &= reset_event_mask;
644                             if (! (connection->notifications_to_deregister & event_mask)){
645                                 avrcp_register_notification(connection, event_id);
646                                 // printf("CHANGED_STABLE notifications_enabled 0x%2x, notifications_to_register 0x%2x\n", connection->notifications_enabled,  connection->notifications_to_register);
647                             } else {
648                                 connection->notifications_to_deregister &= reset_event_mask;
649                             }
650                             break;
651                         default:
652                             connection->notifications_to_register &= reset_event_mask;
653                             connection->notifications_enabled &= reset_event_mask;
654                             connection->notifications_to_deregister &= reset_event_mask;
655                             break;
656                     }
657 
658                     switch (event_id){
659                         case AVRCP_NOTIFICATION_EVENT_PLAYBACK_STATUS_CHANGED:{
660                             uint8_t event[7];
661                             int offset = 0;
662                             event[offset++] = HCI_EVENT_AVRCP_META;
663                             event[offset++] = sizeof(event) - 2;
664                             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_PLAYBACK_STATUS_CHANGED;
665                             little_endian_store_16(event, offset, connection->avrcp_cid);
666                             offset += 2;
667                             event[offset++] = ctype;
668                             event[offset++] = packet[pos];
669                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
670                             break;
671                         }
672                         case AVRCP_NOTIFICATION_EVENT_TRACK_CHANGED:{
673                             uint8_t event[6];
674                             int offset = 0;
675                             event[offset++] = HCI_EVENT_AVRCP_META;
676                             event[offset++] = sizeof(event) - 2;
677                             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_TRACK_CHANGED;
678                             little_endian_store_16(event, offset, connection->avrcp_cid);
679                             offset += 2;
680                             event[offset++] = ctype;
681                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
682                             break;
683                         }
684                         case AVRCP_NOTIFICATION_EVENT_NOW_PLAYING_CONTENT_CHANGED:{
685                             uint8_t event[6];
686                             int offset = 0;
687                             event[offset++] = HCI_EVENT_AVRCP_META;
688                             event[offset++] = sizeof(event) - 2;
689                             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_NOW_PLAYING_CONTENT_CHANGED;
690                             little_endian_store_16(event, offset, connection->avrcp_cid);
691                             offset += 2;
692                             event[offset++] = ctype;
693                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
694                             break;
695                         }
696                         case AVRCP_NOTIFICATION_EVENT_AVAILABLE_PLAYERS_CHANGED:{
697                             uint8_t event[6];
698                             int offset = 0;
699                             event[offset++] = HCI_EVENT_AVRCP_META;
700                             event[offset++] = sizeof(event) - 2;
701                             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_AVAILABLE_PLAYERS_CHANGED;
702                             little_endian_store_16(event, offset, connection->avrcp_cid);
703                             offset += 2;
704                             event[offset++] = ctype;
705                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
706                             break;
707                         }
708                         case AVRCP_NOTIFICATION_EVENT_VOLUME_CHANGED:{
709                             uint8_t event[7];
710                             int offset = 0;
711                             event[offset++] = HCI_EVENT_AVRCP_META;
712                             event[offset++] = sizeof(event) - 2;
713                             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_VOLUME_CHANGED;
714                             little_endian_store_16(event, offset, connection->avrcp_cid);
715                             offset += 2;
716                             event[offset++] = ctype;
717                             event[offset++] = packet[pos++] & 0x7F;
718                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
719                             break;
720                         }
721                         case AVRCP_NOTIFICATION_EVENT_UIDS_CHANGED:{
722                             uint8_t event[7];
723                             int offset = 0;
724                             event[offset++] = HCI_EVENT_AVRCP_META;
725                             event[offset++] = sizeof(event) - 2;
726                             event[offset++] = AVRCP_NOTIFICATION_EVENT_UIDS_CHANGED;
727                             little_endian_store_16(event, offset, connection->avrcp_cid);
728                             offset += 2;
729                             event[offset++] = ctype;
730                             event[offset++] = packet[pos++] & 0x7F;
731                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
732                             break;
733                         }
734 
735                         // case AVRCP_NOTIFICATION_EVENT_PLAYER_APPLICATION_SETTING_CHANGED:{
736                         //     uint8_t num_PlayerApplicationSettingAttributes = packet[pos++];
737                         //     int i;
738                         //     for (i = 0; i < num_PlayerApplicationSettingAttributes; i++){
739                         //         uint8_t PlayerApplicationSetting_AttributeID = packet[pos++];
740                         //         uint8_t PlayerApplicationSettingValueID = packet[pos++];
741                         //     }
742                         //     break;
743                         // }
744                         // case AVRCP_NOTIFICATION_EVENT_ADDRESSED_PLAYER_CHANGED:
745                         //     uint16_t player_id = big_endian_read_16(packet, pos);
746                         //     pos += 2;
747                         //     uint16_t uid_counter = big_endian_read_16(packet, pos);
748                         //     pos += 2;
749                         //     break;
750                         // case AVRCP_NOTIFICATION_EVENT_UIDS_CHANGED:
751                         //     uint16_t uid_counter = big_endian_read_16(packet, pos);
752                         //     pos += 2;
753                         //     break;
754                         default:
755                             log_info("avrcp: not implemented");
756                             break;
757                     }
758                     if (connection->notifications_to_register != 0){
759                         avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
760                     }
761                     break;
762                 }
763 
764                 case AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES:{
765                     avrcp_packet_type_t packet_type = operands[4] & 0x03;
766                     switch (packet_type){
767                         case AVRCP_START_PACKET:
768                         case AVRCP_SINGLE_PACKET:
769                             avrcp_parser_reset(connection);
770                             connection->list_size = param_length;
771                             connection->num_attributes = packet[pos++];
772 
773                             // printf("AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES num_attributes %d, total size %d, packet type 0x%02x \n", connection->num_attributes, connection->list_size, operands[4] & 0x03);
774                             avrcp_source_parse_and_emit_element_attrs(packet+pos, size-pos, connection, ctype);
775 
776                             if (packet_type == AVRCP_START_PACKET){
777                                 avrcp_controller_request_continue_response(connection);
778                             }
779                             break;
780                         case AVRCP_CONTINUE_PACKET:
781                         case AVRCP_END_PACKET:
782                             connection->num_received_fragments++;
783                             if (connection->num_received_fragments < connection->max_num_fragments){
784                                 avrcp_source_parse_and_emit_element_attrs(packet+pos, size-pos, connection, ctype);
785                                 if (packet_type == AVRCP_CONTINUE_PACKET){
786                                     avrcp_controller_request_continue_response(connection);
787                                 }
788                             } else {
789                                 avrcp_controller_request_abort_continuation(connection);
790                                 avrcp_controller_emit_now_playing_info_event_done(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, 1);
791                                 avrcp_parser_reset(connection);
792                             }
793                             break;
794                     }
795                 }
796                 default:
797                     break;
798             }
799             break;
800         case AVRCP_CMD_OPCODE_PASS_THROUGH:{
801             // 0x80 | connection->cmd_operands[0]
802             uint8_t operation_id = packet[pos++];
803             switch (connection->state){
804                 case AVCTP_W2_RECEIVE_PRESS_RESPONSE:
805                     if (connection->continuous_fast_forward_cmd){
806                         connection->state = AVCTP_W4_STOP;
807                     } else {
808                         connection->state = AVCTP_W2_SEND_RELEASE_COMMAND;
809                     }
810                     break;
811                 case AVCTP_W2_RECEIVE_RESPONSE:
812                     connection->state = AVCTP_CONNECTION_OPENED;
813                     break;
814                 default:
815                     // check for notifications? move state transition down
816                     // log_info("AVRCP_CMD_OPCODE_PASS_THROUGH state %d\n", connection->state);
817                     break;
818             }
819             if (connection->state == AVCTP_W4_STOP){
820                 avrcp_emit_operation_status(avrcp_controller_context.avrcp_callback, AVRCP_SUBEVENT_OPERATION_START, connection->avrcp_cid, ctype, operation_id);
821             }
822             if (connection->state == AVCTP_CONNECTION_OPENED) {
823                 // RELEASE response
824                 operation_id = operation_id & 0x7F;
825                 avrcp_emit_operation_status(avrcp_controller_context.avrcp_callback, AVRCP_SUBEVENT_OPERATION_COMPLETE, connection->avrcp_cid, ctype, operation_id);
826             }
827             if (connection->state == AVCTP_W2_SEND_RELEASE_COMMAND){
828                 // PRESS response
829                 request_pass_through_release_control_cmd(connection);
830             }
831             break;
832         }
833         default:
834             break;
835     }
836 }
837 
838 static void avrcp_controller_handle_can_send_now(avrcp_connection_t * connection){
839     int i;
840     switch (connection->state){
841         case AVCTP_W2_SEND_PRESS_COMMAND:
842             connection->state = AVCTP_W2_RECEIVE_PRESS_RESPONSE;
843             avrcp_send_cmd(connection, AVRCP_SINGLE_PACKET);
844             break;
845         case AVCTP_W2_SEND_COMMAND:
846         case AVCTP_W2_SEND_RELEASE_COMMAND:
847             connection->state = AVCTP_W2_RECEIVE_RESPONSE;
848             avrcp_send_cmd(connection, AVRCP_SINGLE_PACKET);
849             break;
850         case AVCTP_CONNECTION_OPENED:
851             if (connection->notifications_to_register != 0){
852                 for (i = 1; i <= AVRCP_NOTIFICATION_EVENT_VOLUME_CHANGED; i++){
853                     if (connection->notifications_to_register & (1<<i)){
854                         connection->notifications_to_register &= ~ (1 << i);
855                         avrcp_prepare_notification(connection, (avrcp_notification_event_id_t) i);
856                         connection->state = AVCTP_W2_RECEIVE_RESPONSE;
857                         avrcp_send_cmd(connection, AVRCP_SINGLE_PACKET);
858                         return;
859                     }
860                 }
861             }
862             return;
863         case AVCTP_W2_SEND_FRAGMENTED_COMMAND:
864             if (connection->cmd_operands_fragmented_pos == 0){
865                  avrcp_send_cmd(connection, AVRCP_START_PACKET);
866                  avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
867             } else {
868                 if (connection->cmd_operands_fragmented_len - connection->cmd_operands_fragmented_pos > avrcp_get_max_payload_size_for_packet_type(AVRCP_CONTINUE_PACKET)){
869                      avrcp_send_cmd(connection, AVRCP_CONTINUE_PACKET);
870                      avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
871                  } else {
872                     connection->state = AVCTP_W2_RECEIVE_RESPONSE;
873                     avrcp_send_cmd(connection, AVRCP_END_PACKET);
874                  }
875             }
876         default:
877             return;
878     }
879 }
880 
881 static void avrcp_controller_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
882     avrcp_connection_t * connection;
883 
884     switch (packet_type) {
885         case L2CAP_DATA_PACKET:
886             connection = get_avrcp_connection_for_l2cap_signaling_cid(channel, &avrcp_controller_context);
887             if (!connection) break;
888             avrcp_handle_l2cap_data_packet_for_signaling_connection(connection, packet, size);
889             break;
890         case HCI_EVENT_PACKET:
891             switch (hci_event_packet_get_type(packet)){
892                 case L2CAP_EVENT_CAN_SEND_NOW:
893                     connection = get_avrcp_connection_for_l2cap_signaling_cid(channel, &avrcp_controller_context);
894                     if (!connection) break;
895                     avrcp_controller_handle_can_send_now(connection);
896                     break;
897             default:
898                 avrcp_packet_handler(packet_type, channel, packet, size, &avrcp_controller_context);
899                 break;
900         }
901         default:
902             break;
903     }
904 }
905 
906 void avrcp_controller_init(void){
907     avrcp_controller_context.role = AVRCP_CONTROLLER;
908     avrcp_controller_context.connections = NULL;
909     avrcp_controller_context.packet_handler = avrcp_controller_packet_handler;
910     l2cap_register_service(&avrcp_controller_packet_handler, BLUETOOTH_PROTOCOL_AVCTP, 0xffff, LEVEL_2);
911 }
912 
913 void avrcp_controller_register_packet_handler(btstack_packet_handler_t callback){
914     if (callback == NULL){
915         log_error("avrcp_register_packet_handler called with NULL callback");
916         return;
917     }
918     avrcp_controller_context.avrcp_callback = callback;
919 }
920 
921 uint8_t avrcp_controller_connect(bd_addr_t bd_addr, uint16_t * avrcp_cid){
922     return avrcp_connect(bd_addr, &avrcp_controller_context, avrcp_cid);
923 }
924 
925 uint8_t avrcp_controller_unit_info(uint16_t avrcp_cid){
926     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
927     if (!connection){
928         log_error("avrcp_unit_info: could not find a connection.");
929         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
930     }
931     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
932     connection->state = AVCTP_W2_SEND_COMMAND;
933 
934     connection->transaction_label++;
935     connection->command_opcode = AVRCP_CMD_OPCODE_UNIT_INFO;
936     connection->command_type = AVRCP_CTYPE_STATUS;
937     connection->subunit_type = AVRCP_SUBUNIT_TYPE_UNIT; //vendor unique
938     connection->subunit_id =   AVRCP_SUBUNIT_ID_IGNORE;
939     memset(connection->cmd_operands, 0xFF, connection->cmd_operands_length);
940     connection->cmd_operands_length = 5;
941     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
942     return ERROR_CODE_SUCCESS;
943 }
944 
945 uint8_t avrcp_controller_subunit_info(uint16_t avrcp_cid){
946     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
947     if (!connection){
948         log_error("avrcp_unit_info: could not find a connection.");
949         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
950     }
951     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
952     connection->state = AVCTP_W2_SEND_COMMAND;
953 
954     connection->transaction_label++;
955     connection->command_opcode = AVRCP_CMD_OPCODE_SUBUNIT_INFO;
956     connection->command_type = AVRCP_CTYPE_STATUS;
957     connection->subunit_type = AVRCP_SUBUNIT_TYPE_UNIT; //vendor unique
958     connection->subunit_id =   AVRCP_SUBUNIT_ID_IGNORE;
959     memset(connection->cmd_operands, 0xFF, connection->cmd_operands_length);
960     connection->cmd_operands[0] = 7; // page: 0, extention_code: 7
961     connection->cmd_operands_length = 5;
962     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
963     return ERROR_CODE_SUCCESS;
964 }
965 
966 static uint8_t avrcp_controller_get_capabilities(uint16_t avrcp_cid, uint8_t capability_id){
967     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
968     if (!connection){
969         log_error("avrcp_get_capabilities: could not find a connection.");
970         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
971     }
972     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
973     connection->state = AVCTP_W2_SEND_COMMAND;
974 
975     connection->transaction_label++;
976     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
977     connection->command_type = AVRCP_CTYPE_STATUS;
978     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
979     connection->subunit_id = AVRCP_SUBUNIT_ID;
980     big_endian_store_24(connection->cmd_operands, 0, BT_SIG_COMPANY_ID);
981     connection->cmd_operands[3] = AVRCP_PDU_ID_GET_CAPABILITIES; // PDU ID
982     connection->cmd_operands[4] = 0;
983     big_endian_store_16(connection->cmd_operands, 5, 1); // parameter length
984     connection->cmd_operands[7] = capability_id;                  // capability ID
985     connection->cmd_operands_length = 8;
986     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
987     return ERROR_CODE_SUCCESS;
988 }
989 
990 uint8_t avrcp_controller_get_supported_company_ids(uint16_t avrcp_cid){
991     return avrcp_controller_get_capabilities(avrcp_cid, AVRCP_CAPABILITY_ID_COMPANY);
992 }
993 
994 uint8_t avrcp_controller_get_supported_events(uint16_t avrcp_cid){
995     return avrcp_controller_get_capabilities(avrcp_cid, AVRCP_CAPABILITY_ID_EVENT);
996 }
997 
998 
999 uint8_t avrcp_controller_play(uint16_t avrcp_cid){
1000     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PLAY, 0);
1001 }
1002 
1003 uint8_t avrcp_controller_stop(uint16_t avrcp_cid){
1004     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_STOP, 0);
1005 }
1006 
1007 uint8_t avrcp_controller_pause(uint16_t avrcp_cid){
1008     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PAUSE, 0);
1009 }
1010 
1011 uint8_t avrcp_controller_forward(uint16_t avrcp_cid){
1012     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FORWARD, 0);
1013 }
1014 
1015 uint8_t avrcp_controller_backward(uint16_t avrcp_cid){
1016     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_BACKWARD, 0);
1017 }
1018 
1019 uint8_t avrcp_controller_volume_up(uint16_t avrcp_cid){
1020     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_UP, 0);
1021 }
1022 
1023 uint8_t avrcp_controller_volume_down(uint16_t avrcp_cid){
1024     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_DOWN, 0);
1025 }
1026 
1027 uint8_t avrcp_controller_mute(uint16_t avrcp_cid){
1028     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_MUTE, 0);
1029 }
1030 
1031 uint8_t avrcp_controller_skip(uint16_t avrcp_cid){
1032     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_SKIP, 0);
1033 }
1034 
1035 uint8_t avrcp_controller_fast_forward(uint16_t avrcp_cid){
1036     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FAST_FORWARD, 0);
1037 }
1038 
1039 uint8_t avrcp_controller_rewind(uint16_t avrcp_cid){
1040     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_REWIND, 0);
1041 }
1042 
1043 
1044 /* start cmds */
1045 
1046 uint8_t avrcp_controller_release_press_and_hold_cmd(uint16_t avrcp_cid){
1047     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1048     if (!connection){
1049         log_error("avrcp_stop_play: could not find a connection.");
1050         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1051     }
1052     if (connection->state != AVCTP_W4_STOP) return ERROR_CODE_COMMAND_DISALLOWED;
1053     return request_pass_through_release_control_cmd(connection);
1054 }
1055 
1056 uint8_t avrcp_controller_press_and_hold_play(uint16_t avrcp_cid){
1057     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PLAY, 0);
1058 }
1059 uint8_t avrcp_controller_press_and_hold_stop(uint16_t avrcp_cid){
1060     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_STOP, 0);
1061 }
1062 uint8_t avrcp_controller_press_and_hold_pause(uint16_t avrcp_cid){
1063     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PAUSE, 0);
1064 }
1065 uint8_t avrcp_controller_press_and_hold_forward(uint16_t avrcp_cid){
1066     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FORWARD, 0);
1067 }
1068 uint8_t avrcp_controller_press_and_hold_backward(uint16_t avrcp_cid){
1069     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_BACKWARD, 0);
1070 }
1071 uint8_t avrcp_controller_press_and_hold_fast_forward(uint16_t avrcp_cid){
1072     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FAST_FORWARD, 0);
1073 }
1074 uint8_t avrcp_controller_press_and_hold_rewind(uint16_t avrcp_cid){
1075     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_REWIND, 0);
1076 }
1077 uint8_t avrcp_controller_press_and_hold_volume_up(uint16_t avrcp_cid){
1078     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_UP, 0);
1079 }
1080 uint8_t avrcp_controller_press_and_hold_volume_down(uint16_t avrcp_cid){
1081     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_DOWN, 0);
1082 }
1083 uint8_t avrcp_controller_press_and_hold_mute(uint16_t avrcp_cid){
1084     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_MUTE, 0);
1085 }
1086 
1087 
1088 /* stop continuous cmds */
1089 
1090 uint8_t avrcp_controller_get_play_status(uint16_t avrcp_cid){
1091     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1092     if (!connection){
1093         log_error("avrcp_get_play_status: could not find a connection.");
1094         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1095     }
1096     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1097     connection->state = AVCTP_W2_SEND_COMMAND;
1098     connection->transaction_label++;
1099     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1100     connection->command_type = AVRCP_CTYPE_STATUS;
1101     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1102     connection->subunit_id = AVRCP_SUBUNIT_ID;
1103     big_endian_store_24(connection->cmd_operands, 0, BT_SIG_COMPANY_ID);
1104     connection->cmd_operands[3] = AVRCP_PDU_ID_GET_PLAY_STATUS;
1105     connection->cmd_operands[4] = 0;                     // reserved(upper 6) | packet_type -> 0
1106     big_endian_store_16(connection->cmd_operands, 5, 0); // parameter length
1107     connection->cmd_operands_length = 7;
1108     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1109     return ERROR_CODE_SUCCESS;
1110 }
1111 
1112 uint8_t avrcp_controller_enable_notification(uint16_t avrcp_cid, avrcp_notification_event_id_t event_id){
1113     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1114     if (!connection){
1115         log_error("avrcp_get_play_status: could not find a connection.");
1116         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1117     }
1118     avrcp_register_notification(connection, event_id);
1119     return ERROR_CODE_SUCCESS;
1120 }
1121 
1122 uint8_t avrcp_controller_disable_notification(uint16_t avrcp_cid, avrcp_notification_event_id_t event_id){
1123     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1124     if (!connection){
1125         log_error("avrcp_get_play_status: could not find a connection.");
1126         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1127     }
1128     connection->notifications_to_deregister |= (1 << event_id);
1129     return ERROR_CODE_SUCCESS;
1130 }
1131 
1132 uint8_t avrcp_controller_set_addressed_player(uint16_t avrcp_cid, uint16_t addressed_player_id){
1133     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1134     if (!connection){
1135         log_error("avrcp_get_capabilities: could not find a connection.");
1136         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1137     }
1138     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1139     connection->state = AVCTP_W2_SEND_COMMAND;
1140 
1141     connection->transaction_label++;
1142     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1143     connection->command_type = AVRCP_CTYPE_CONTROL;
1144     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1145     connection->subunit_id = AVRCP_SUBUNIT_ID;
1146     int pos = 0;
1147     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1148     pos += 3;
1149     connection->cmd_operands[pos++] = AVRCP_PDU_ID_SET_ADDRESSED_PLAYER; // PDU ID
1150     connection->cmd_operands[pos++] = 0;
1151 
1152     // Parameter Length
1153     big_endian_store_16(connection->cmd_operands, pos, 2);
1154     pos += 2;
1155 
1156     big_endian_store_16(connection->cmd_operands, pos, addressed_player_id);
1157     pos += 2;
1158 
1159     connection->cmd_operands_length = pos;
1160     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1161     return ERROR_CODE_SUCCESS;
1162 }
1163 
1164 uint8_t avrcp_controller_get_now_playing_info(uint16_t avrcp_cid){
1165     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1166     if (!connection){
1167         log_error("avrcp_get_capabilities: could not find a connection.");
1168         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1169     }
1170     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1171     connection->state = AVCTP_W2_SEND_COMMAND;
1172 
1173     connection->transaction_label++;
1174     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1175     connection->command_type = AVRCP_CTYPE_STATUS;
1176     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1177     connection->subunit_id = AVRCP_SUBUNIT_ID;
1178     int pos = 0;
1179     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1180     pos += 3;
1181     connection->cmd_operands[pos++] = AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES; // PDU ID
1182     connection->cmd_operands[pos++] = 0;
1183 
1184     // Parameter Length
1185     big_endian_store_16(connection->cmd_operands, pos, 9);
1186     pos += 2;
1187 
1188     // write 8 bytes value
1189     memset(connection->cmd_operands + pos, 0, 8); // identifier: PLAYING
1190     pos += 8;
1191 
1192     connection->cmd_operands[pos++] = 0; // attribute count, if 0 get all attributes
1193     // every attribute is 4 bytes long
1194 
1195     connection->cmd_operands_length = pos;
1196     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1197     return ERROR_CODE_SUCCESS;
1198 }
1199 
1200 uint8_t avrcp_controller_set_absolute_volume(uint16_t avrcp_cid, uint8_t volume){
1201      avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1202     if (!connection){
1203         log_error("avrcp_get_capabilities: could not find a connection.");
1204         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1205     }
1206     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1207     connection->state = AVCTP_W2_SEND_COMMAND;
1208 
1209     connection->transaction_label++;
1210     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1211     connection->command_type = AVRCP_CTYPE_CONTROL;
1212     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1213     connection->subunit_id = AVRCP_SUBUNIT_ID;
1214     int pos = 0;
1215     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1216     pos += 3;
1217     connection->cmd_operands[pos++] = AVRCP_PDU_ID_SET_ABSOLUTE_VOLUME; // PDU ID
1218     connection->cmd_operands[pos++] = 0;
1219 
1220     // Parameter Length
1221     big_endian_store_16(connection->cmd_operands, pos, 1);
1222     pos += 2;
1223     connection->cmd_operands[pos++] = volume;
1224 
1225     connection->cmd_operands_length = pos;
1226     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1227     return ERROR_CODE_SUCCESS;
1228 }
1229 
1230 uint8_t avrcp_controller_query_shuffle_and_repeat_modes(uint16_t avrcp_cid){
1231     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1232     if (!connection){
1233         log_error("avrcp_get_capabilities: could not find a connection.");
1234         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1235     }
1236     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1237     connection->state = AVCTP_W2_SEND_COMMAND;
1238 
1239     connection->transaction_label++;
1240     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1241     connection->command_type = AVRCP_CTYPE_STATUS;
1242     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1243     connection->subunit_id = AVRCP_SUBUNIT_ID;
1244     big_endian_store_24(connection->cmd_operands, 0, BT_SIG_COMPANY_ID);
1245     connection->cmd_operands[3] = AVRCP_PDU_ID_GetCurrentPlayerApplicationSettingValue; // PDU ID
1246     connection->cmd_operands[4] = 0;
1247     big_endian_store_16(connection->cmd_operands, 5, 5); // parameter length
1248     connection->cmd_operands[7] = 4;                     // NumPlayerApplicationSettingAttributeID
1249     // PlayerApplicationSettingAttributeID1 AVRCP Spec, Appendix F, 133
1250     connection->cmd_operands[8]  = 0x01;    // equalizer  (1-OFF, 2-ON)
1251     connection->cmd_operands[9]  = 0x02;    // repeat     (1-off, 2-single track, 3-all tracks, 4-group repeat)
1252     connection->cmd_operands[10] = 0x03;    // shuffle    (1-off, 2-all tracks, 3-group shuffle)
1253     connection->cmd_operands[11] = 0x04;    // scan       (1-off, 2-all tracks, 3-group scan)
1254     connection->cmd_operands_length = 12;
1255     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1256     return ERROR_CODE_SUCCESS;
1257 }
1258 
1259 static uint8_t avrcp_controller_set_current_player_application_setting_value(uint16_t avrcp_cid, uint8_t attr_id, uint8_t attr_value){
1260     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1261     if (!connection){
1262         log_error("avrcp_get_capabilities: could not find a connection.");
1263         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1264     }
1265     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1266     connection->state = AVCTP_W2_SEND_COMMAND;
1267 
1268     connection->transaction_label++;
1269     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1270     connection->command_type = AVRCP_CTYPE_CONTROL;
1271     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1272     connection->subunit_id = AVRCP_SUBUNIT_ID;
1273     int pos = 0;
1274     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1275     pos += 3;
1276     connection->cmd_operands[pos++] = AVRCP_PDU_ID_SetPlayerApplicationSettingValue; // PDU ID
1277     connection->cmd_operands[pos++] = 0;
1278     // Parameter Length
1279     big_endian_store_16(connection->cmd_operands, pos, 3);
1280     pos += 2;
1281     connection->cmd_operands[pos++] = 2;
1282     connection->cmd_operands_length = pos;
1283     connection->cmd_operands[pos++]  = attr_id;
1284     connection->cmd_operands[pos++]  = attr_value;
1285     connection->cmd_operands_length = pos;
1286     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1287     return ERROR_CODE_SUCCESS;
1288 }
1289 
1290 uint8_t avrcp_controller_set_shuffle_mode(uint16_t avrcp_cid, avrcp_shuffle_mode_t mode){
1291     if (mode < AVRCP_SHUFFLE_MODE_OFF || mode > AVRCP_SHUFFLE_MODE_GROUP) return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
1292     return avrcp_controller_set_current_player_application_setting_value(avrcp_cid, 0x03, mode);
1293 }
1294 
1295 uint8_t avrcp_controller_set_repeat_mode(uint16_t avrcp_cid, avrcp_repeat_mode_t mode){
1296     if (mode < AVRCP_REPEAT_MODE_OFF || mode > AVRCP_REPEAT_MODE_GROUP) return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
1297     return avrcp_controller_set_current_player_application_setting_value(avrcp_cid, 0x02, mode);
1298 }
1299 
1300 uint8_t avrcp_controller_disconnect(uint16_t avrcp_cid){
1301     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1302     if (!connection){
1303         log_error("avrcp_get_capabilities: could not find a connection.");
1304         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1305     }
1306     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1307     if (connection->browsing_connection){
1308         if (connection->browsing_connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1309         l2cap_disconnect(connection->browsing_connection->l2cap_browsing_cid, 0);
1310     }
1311     l2cap_disconnect(connection->l2cap_signaling_cid, 0);
1312     return ERROR_CODE_SUCCESS;
1313 }
1314 
1315 uint8_t avrcp_controller_play_item_for_scope(uint16_t avrcp_cid, uint8_t * uid, uint16_t uid_counter, avrcp_browsing_scope_t scope){
1316     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1317     if (!connection){
1318         log_error("Could not find a connection with cid 0%02x.", avrcp_cid);
1319         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1320     }
1321     if (connection->state != AVCTP_CONNECTION_OPENED){
1322         log_error("Connection in wrong state, expected %d, received %d", AVCTP_CONNECTION_OPENED, connection->state);
1323         return ERROR_CODE_COMMAND_DISALLOWED;
1324     }
1325     connection->state = AVCTP_W2_SEND_COMMAND;
1326 
1327     connection->transaction_label++;
1328     connection->command_type = AVRCP_CTYPE_CONTROL;
1329     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1330     connection->subunit_id = AVRCP_SUBUNIT_ID;
1331     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1332     int pos = 0;
1333     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1334     pos += 3;
1335     connection->cmd_operands[pos++] = AVRCP_PDU_ID_PLAY_ITEM; // PDU ID
1336     // reserved
1337     connection->cmd_operands[pos++] = 0;
1338     // Parameter Length
1339     big_endian_store_16(connection->cmd_operands, pos, 11);
1340     pos += 2;
1341     connection->cmd_operands[pos++]  = scope;
1342     memset(&connection->cmd_operands[pos], 0, 8);
1343     if (uid){
1344         memcpy(&connection->cmd_operands[pos], uid, 8);
1345     }
1346     pos += 8;
1347     big_endian_store_16(connection->cmd_operands, pos, uid_counter);
1348     pos += 2;
1349     connection->cmd_operands_length = pos;
1350 
1351     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1352     return ERROR_CODE_SUCCESS;
1353 }
1354 
1355 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){
1356     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1357     if (!connection){
1358         log_error("Could not find a connection with cid 0%02x.", avrcp_cid);
1359         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1360     }
1361     if (connection->state != AVCTP_CONNECTION_OPENED){
1362         log_error("Connection in wrong state, expected %d, received %d", AVCTP_CONNECTION_OPENED, connection->state);
1363         return ERROR_CODE_COMMAND_DISALLOWED;
1364     }
1365     connection->state = AVCTP_W2_SEND_COMMAND;
1366 
1367     connection->transaction_label++;
1368     connection->command_type = AVRCP_CTYPE_CONTROL;
1369     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
1370     connection->subunit_id = AVRCP_SUBUNIT_ID;
1371     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
1372     int pos = 0;
1373     big_endian_store_24(connection->cmd_operands, pos, BT_SIG_COMPANY_ID);
1374     pos += 3;
1375     connection->cmd_operands[pos++] = AVRCP_PDU_ID_ADD_TO_NOW_PLAYING; // PDU ID
1376     // reserved
1377     connection->cmd_operands[pos++] = 0;
1378     // Parameter Length
1379     big_endian_store_16(connection->cmd_operands, pos, 11);
1380     pos += 2;
1381     connection->cmd_operands[pos++]  = scope;
1382     memset(&connection->cmd_operands[pos], 0, 8);
1383     if (uid){
1384         memcpy(&connection->cmd_operands[pos], uid, 8);
1385     }
1386     pos += 8;
1387     big_endian_store_16(connection->cmd_operands, pos, uid_counter);
1388     pos += 2;
1389     connection->cmd_operands_length = pos;
1390 
1391     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1392     return ERROR_CODE_SUCCESS;
1393 }
1394 
1395 uint8_t avrcp_controller_set_max_num_fragments(uint16_t avrcp_cid, uint8_t max_num_fragments){
1396     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1397     if (!connection){
1398         log_error("avrcp_controller_play_item: could not find a connection.");
1399         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1400     }
1401     connection->max_num_fragments = max_num_fragments;
1402     return ERROR_CODE_SUCCESS;
1403 }
1404 
1405 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){
1406     avrcp_connection_t * connection = get_avrcp_connection_for_avrcp_cid(avrcp_cid, &avrcp_controller_context);
1407     if (!connection){
1408         log_error("avrcp_controller_play_item: could not find a connection.");
1409         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1410     }
1411 
1412     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1413     connection->state = AVCTP_W2_SEND_FRAGMENTED_COMMAND;
1414 
1415     connection->transaction_label++;
1416     connection->command_opcode = command_opcode;
1417     connection->command_type = command_type;
1418     connection->subunit_type = subunit_type;
1419     connection->subunit_id = subunit_id;
1420     connection->cmd_operands_fragmented_buffer = command_buffer;
1421     connection->cmd_operands_fragmented_pos = 0;
1422     connection->cmd_operands_fragmented_len = command_len;
1423 
1424     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1425     return ERROR_CODE_SUCCESS;
1426 }
1427