xref: /btstack/src/classic/avrcp_controller.c (revision 5c72796b163aa32d9bd5c6a01ae06e840b4c9a94)
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 BLUEKITCHEN
24  * GMBH OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at
34  * [email protected]
35  *
36  */
37 
38 #define BTSTACK_FILE__ "avrcp_controller.c"
39 
40 #include <stdint.h>
41 #include <string.h>
42 #include <inttypes.h>
43 
44 #include "classic/avrcp.h"
45 #include "classic/avrcp_controller.h"
46 
47 #include "bluetooth_sdp.h"
48 #include "btstack_debug.h"
49 #include "btstack_event.h"
50 
51 static const char * avrcp_default_controller_service_name = "AVRCP Controller";
52 static const char * avrcp_default_controller_service_provider_name = "BlueKitchen";
53 
54 // made public in avrcp_controller.h
55 avrcp_context_t avrcp_controller_context;
56 
57 static uint8_t avrcp_controller_calc_next_transaction_label(uint8_t current_transaction_label){
58     current_transaction_label++;
59     if (current_transaction_label == 16){
60         current_transaction_label = 1;
61     }
62     return current_transaction_label;
63 }
64 
65 static uint8_t avrcp_controller_get_next_transaction_label(avrcp_connection_t * connection){
66     connection->transaction_id_counter = avrcp_controller_calc_next_transaction_label(connection->transaction_id_counter);
67     return connection->transaction_id_counter;
68 }
69 
70 static bool avrcp_controller_is_transaction_id_valid(avrcp_connection_t * connection, uint8_t transaction_id){
71     uint8_t delta = ((int8_t) transaction_id - connection->controller_last_confirmed_transaction_id) & 0x0f;
72     return delta < 15;
73 }
74 
75 static void avrcp_controller_custom_command_data_init(avrcp_connection_t * connection,
76                                                       avrcp_command_opcode_t opcode, avrcp_command_type_t command_type,
77                                                       avrcp_subunit_type_t subunit_type, avrcp_subunit_id_t subunit_id,
78                                                       avrcp_pdu_id_t pdu_id, uint32_t company_id){
79 
80     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
81     connection->command_opcode = opcode;
82     connection->command_type = command_type;
83     connection->subunit_type = subunit_type;
84     connection->subunit_id = subunit_id;
85     connection->company_id = company_id;
86     connection->pdu_id = pdu_id;
87     connection->data = NULL;
88     connection->data_offset = 0;
89     connection->data_len = 0;
90 }
91 
92 static void avrcp_controller_vendor_dependent_command_data_init(avrcp_connection_t * connection, avrcp_command_type_t command_type, avrcp_pdu_id_t pdu_id, bool get_next_transaction_label){
93     if (get_next_transaction_label){
94         connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
95     }
96     connection->command_opcode = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
97     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
98     connection->subunit_id = AVRCP_SUBUNIT_ID;
99     connection->company_id = BT_SIG_COMPANY_ID;
100 
101     connection->command_type = command_type;
102     connection->pdu_id = pdu_id;
103     connection->data = connection->message_body;
104     connection->data_offset = 0;
105     connection->data_len = 0;
106 }
107 
108 static void avrcp_controller_pass_through_command_data_init(avrcp_connection_t * connection, avrcp_operation_id_t opid){
109     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
110     connection->command_opcode =  AVRCP_CMD_OPCODE_PASS_THROUGH;
111     connection->command_type = AVRCP_CTYPE_CONTROL;
112     connection->subunit_type = AVRCP_SUBUNIT_TYPE_PANEL;
113     connection->subunit_id =   AVRCP_SUBUNIT_ID;
114 
115     connection->company_id = 0;
116     connection->pdu_id = AVRCP_PDU_ID_UNDEFINED;
117     connection->operation_id = opid;
118 
119     connection->data = connection->message_body;
120     connection->data_offset = 0;
121     connection->data_len = 0;
122 }
123 
124 static int avrcp_controller_supports_browsing(uint16_t controller_supported_features){
125     return controller_supported_features & AVRCP_FEATURE_MASK_BROWSING;
126 }
127 
128 static void avrcp_controller_prepare_custom_command_response(avrcp_connection_t * connection, uint16_t response_len, uint8_t * in_place_buffer){
129     uint8_t pos = 0;
130     in_place_buffer[pos++] = HCI_EVENT_AVRCP_META;
131     // skip len
132     pos++;
133     in_place_buffer[pos++] = AVRCP_SUBEVENT_CUSTOM_COMMAND_RESPONSE;
134     little_endian_store_16(in_place_buffer, pos, connection->avrcp_cid);
135     pos += 2;
136     in_place_buffer[pos++] = (uint8_t)connection->command_type;
137     in_place_buffer[pos++] = (uint8_t)connection->pdu_id;
138     little_endian_store_16(in_place_buffer, pos, response_len);
139     pos += 2;
140     in_place_buffer[1] = pos + response_len - 2;
141 }
142 
143 static void avrcp_controller_emit_notification_complete(avrcp_connection_t * connection, uint8_t status, uint8_t event_id, bool enabled){
144     uint8_t event[8];
145     uint8_t pos = 0;
146     event[pos++] = HCI_EVENT_AVRCP_META;
147     event[pos++] = sizeof(event) - 2;
148     event[pos++] = AVRCP_SUBEVENT_NOTIFICATION_STATE;
149     little_endian_store_16(event, pos, connection->avrcp_cid);
150     pos += 2;
151     event[pos++] = status;
152     event[pos++] = enabled ? 1 : 0;
153     event[pos++] = event_id;
154     UNUSED(pos);
155     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
156 }
157 
158 static void avrcp_controller_emit_supported_events(avrcp_connection_t * connection){
159     uint8_t ctype = (uint8_t) AVRCP_CTYPE_RESPONSE_CHANGED_STABLE;
160     uint8_t event_id;
161 
162     for (event_id = (uint8_t) AVRCP_NOTIFICATION_EVENT_FIRST_INDEX; event_id < (uint8_t) AVRCP_NOTIFICATION_EVENT_LAST_INDEX; event_id++){
163         if ((connection->notifications_supported_by_target & (1 << event_id)) == 0){
164             continue;
165         }
166         uint8_t event[8];
167         uint8_t pos = 0;
168         event[pos++] = HCI_EVENT_AVRCP_META;
169         event[pos++] = sizeof(event) - 2;
170         event[pos++] = AVRCP_SUBEVENT_GET_CAPABILITY_EVENT_ID;
171         little_endian_store_16(event, pos, connection->avrcp_cid);
172         pos += 2;
173         event[pos++] = ctype;
174         event[pos++] = 0;
175         event[pos++] = event_id;
176         UNUSED(pos);
177         (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
178     }
179 
180     uint8_t event[7];
181     uint8_t pos = 0;
182     event[pos++] = HCI_EVENT_AVRCP_META;
183     event[pos++] = sizeof(event) - 2;
184     event[pos++] = AVRCP_SUBEVENT_GET_CAPABILITY_EVENT_ID_DONE;
185     little_endian_store_16(event, pos, connection->avrcp_cid);
186     pos += 2;
187     event[pos++] = ctype;
188     event[pos++] = 0;
189     UNUSED(pos);
190     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
191 }
192 
193 static void avrcp_controller_emit_notification_for_event_id(uint16_t avrcp_cid, avrcp_notification_event_id_t event_id,
194                                                             avrcp_command_type_t ctype, const uint8_t *payload,
195                                                             uint16_t size) {
196     switch (event_id){
197         case AVRCP_NOTIFICATION_EVENT_PLAYBACK_POS_CHANGED:{
198             if (size < 4) break;
199             uint32_t song_position = big_endian_read_32(payload, 0);
200             uint16_t offset = 0;
201             uint8_t event[10];
202             event[offset++] = HCI_EVENT_AVRCP_META;
203             event[offset++] = sizeof(event) - 2;
204             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_PLAYBACK_POS_CHANGED;
205             little_endian_store_16(event, offset, avrcp_cid);
206             offset += 2;
207             event[offset++] = ctype;
208             little_endian_store_32(event, offset, song_position);
209             offset += 4;
210             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, offset);
211             break;
212         }
213         case AVRCP_NOTIFICATION_EVENT_PLAYBACK_STATUS_CHANGED:{
214             if (size < 1) break;
215             uint16_t offset = 0;
216             uint8_t event[7];
217             event[offset++] = HCI_EVENT_AVRCP_META;
218             event[offset++] = sizeof(event) - 2;
219             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_PLAYBACK_STATUS_CHANGED;
220             little_endian_store_16(event, offset, avrcp_cid);
221             offset += 2;
222             event[offset++] = ctype;
223             event[offset++] = payload[0];
224             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, offset);
225             break;
226         }
227         case AVRCP_NOTIFICATION_EVENT_TRACK_CHANGED:{
228             uint16_t offset = 0;
229             uint8_t event[6];
230             event[offset++] = HCI_EVENT_AVRCP_META;
231             event[offset++] = sizeof(event) - 2;
232             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_TRACK_CHANGED;
233             little_endian_store_16(event, offset, avrcp_cid);
234             offset += 2;
235             event[offset++] = ctype;
236             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, offset);
237             break;
238         }
239         case AVRCP_NOTIFICATION_EVENT_NOW_PLAYING_CONTENT_CHANGED:{
240             uint16_t offset = 0;
241             uint8_t event[6];
242             event[offset++] = HCI_EVENT_AVRCP_META;
243             event[offset++] = sizeof(event) - 2;
244             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_NOW_PLAYING_CONTENT_CHANGED;
245             little_endian_store_16(event, offset, avrcp_cid);
246             offset += 2;
247             event[offset++] = ctype;
248             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, offset);
249             break;
250         }
251         case AVRCP_NOTIFICATION_EVENT_AVAILABLE_PLAYERS_CHANGED:{
252             uint16_t offset = 0;
253             uint8_t event[6];
254             event[offset++] = HCI_EVENT_AVRCP_META;
255             event[offset++] = sizeof(event) - 2;
256             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_AVAILABLE_PLAYERS_CHANGED;
257             little_endian_store_16(event, offset, avrcp_cid);
258             offset += 2;
259             event[offset++] = ctype;
260             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, offset);
261             break;
262         }
263         case AVRCP_NOTIFICATION_EVENT_VOLUME_CHANGED:{
264             if (size < 1) break;
265             uint16_t offset = 0;
266             uint8_t event[7];
267             event[offset++] = HCI_EVENT_AVRCP_META;
268             event[offset++] = sizeof(event) - 2;
269             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_VOLUME_CHANGED;
270             little_endian_store_16(event, offset, avrcp_cid);
271             offset += 2;
272             event[offset++] = ctype;
273             event[offset++] = payload[0] & 0x7F;
274             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, offset);
275             break;
276         }
277         case AVRCP_NOTIFICATION_EVENT_UIDS_CHANGED:{
278             if (size < 2) break;
279             uint8_t event[8];
280             uint16_t offset = 0;
281             uint16_t uuid = big_endian_read_16(payload, 0);
282             event[offset++] = HCI_EVENT_AVRCP_META;
283             event[offset++] = sizeof(event) - 2;
284             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_UIDS_CHANGED;
285             little_endian_store_16(event, offset, avrcp_cid);
286             offset += 2;
287             event[offset++] = ctype;
288             little_endian_store_16(event, offset, uuid);
289             offset += 2;
290             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, offset);
291             break;
292         }
293 
294         case AVRCP_NOTIFICATION_EVENT_TRACK_REACHED_END:{
295             uint16_t offset = 0;
296             uint8_t event[6];
297             event[offset++] = HCI_EVENT_AVRCP_META;
298             event[offset++] = sizeof(event) - 2;
299             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_TRACK_REACHED_END;
300             little_endian_store_16(event, offset, avrcp_cid);
301             offset += 2;
302             event[offset++] = ctype;
303             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, offset);
304             break;
305         }
306         case AVRCP_NOTIFICATION_EVENT_TRACK_REACHED_START:{
307             uint16_t offset = 0;
308             uint8_t event[6];
309             event[offset++] = HCI_EVENT_AVRCP_META;
310             event[offset++] = sizeof(event) - 2;
311             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_TRACK_REACHED_START;
312             little_endian_store_16(event, offset, avrcp_cid);
313             offset += 2;
314             event[offset++] = ctype;
315             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, offset);
316             break;
317         }
318         case AVRCP_NOTIFICATION_EVENT_BATT_STATUS_CHANGED:{
319             if (size < 1) break;
320             uint16_t offset = 0;
321             uint8_t event[7];
322             event[offset++] = HCI_EVENT_AVRCP_META;
323             event[offset++] = sizeof(event) - 2;
324             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_BATT_STATUS_CHANGED;
325             little_endian_store_16(event, offset, avrcp_cid);
326             offset += 2;
327             event[offset++] = ctype;
328             event[offset++] = payload[0];
329             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, offset);
330             break;
331         }
332 
333         case AVRCP_NOTIFICATION_EVENT_SYSTEM_STATUS_CHANGED:{
334             if (size < 1) break;
335             uint16_t offset = 0;
336             uint8_t event[7];
337             event[offset++] = HCI_EVENT_AVRCP_META;
338             event[offset++] = sizeof(event) - 2;
339             event[offset++] = AVRCP_SUBEVENT_NOTIFICATION_EVENT_SYSTEM_STATUS_CHANGED;
340             little_endian_store_16(event, offset, avrcp_cid);
341             offset += 2;
342             event[offset++] = ctype;
343             event[offset++] = payload[0];
344             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, offset);
345             break;
346         }
347 
348         case AVRCP_NOTIFICATION_EVENT_PLAYER_APPLICATION_SETTING_CHANGED:
349         default:
350             log_info("avrcp: not implemented");
351             break;
352     }
353 }
354 
355 static void avrcp_controller_emit_repeat_and_shuffle_mode(btstack_packet_handler_t callback, uint16_t avrcp_cid, uint8_t ctype, avrcp_repeat_mode_t repeat_mode, avrcp_shuffle_mode_t shuffle_mode){
356     btstack_assert(callback != NULL);
357 
358     uint8_t event[8];
359     int pos = 0;
360     event[pos++] = HCI_EVENT_AVRCP_META;
361     event[pos++] = sizeof(event) - 2;
362     event[pos++] = AVRCP_SUBEVENT_SHUFFLE_AND_REPEAT_MODE;
363     little_endian_store_16(event, pos, avrcp_cid);
364     pos += 2;
365     event[pos++] = ctype;
366     event[pos++] = repeat_mode;
367     event[pos++] = shuffle_mode;
368     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
369 }
370 
371 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){
372     uint8_t event[7];
373     int pos = 0;
374     event[pos++] = HCI_EVENT_AVRCP_META;
375     event[pos++] = sizeof(event) - 2;
376     event[pos++] = AVRCP_SUBEVENT_NOW_PLAYING_INFO_DONE;
377     little_endian_store_16(event, pos, avrcp_cid);
378     pos += 2;
379     event[pos++] = ctype;
380     event[pos++] = status;
381     (*callback)(HCI_EVENT_PACKET, 0, event, pos);
382 }
383 
384 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){
385     uint8_t event[HCI_EVENT_BUFFER_SIZE];
386     uint16_t pos = 0;
387     event[pos++] = HCI_EVENT_AVRCP_META;
388     // reserve one byte for subevent type and data len
389 	uint16_t data_len_pos = pos;
390     pos++;
391 	uint16_t subevent_type_pos = pos;
392     pos++;
393     little_endian_store_16(event, pos, avrcp_cid);
394     pos += 2;
395     event[pos++] = ctype;
396 
397     switch (attr_id){
398         case AVRCP_MEDIA_ATTR_TITLE:
399             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TITLE_INFO;
400 			btstack_assert(value_len <= 255);
401             event[pos++] = (uint8_t) value_len;
402             (void)memcpy(event + pos, value, value_len);
403             break;
404         case AVRCP_MEDIA_ATTR_ARTIST:
405             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_ARTIST_INFO;
406 			btstack_assert(value_len <= 255);
407 			event[pos++] = (uint8_t) value_len;
408             (void)memcpy(event + pos, value, value_len);
409             break;
410         case AVRCP_MEDIA_ATTR_ALBUM:
411             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_ALBUM_INFO;
412 			btstack_assert(value_len <= 255);
413 			event[pos++] = (uint8_t) value_len;
414             (void)memcpy(event + pos, value, value_len);
415             break;
416         case AVRCP_MEDIA_ATTR_GENRE:
417             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_GENRE_INFO;
418 			btstack_assert(value_len <= 255);
419 			event[pos++] = (uint8_t) value_len;
420             (void)memcpy(event + pos, value, value_len);
421             break;
422 #ifdef ENABLE_AVRCP_COVER_ART
423         case AVRCP_MEDIA_ATTR_DEFAULT_COVER_ART:
424             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_COVER_ART_INFO;
425             btstack_assert(value_len <= 255);
426             event[pos++] = (uint8_t) value_len;
427             (void)memcpy(event + pos, value, value_len);
428             break;
429 #endif
430         case AVRCP_MEDIA_ATTR_SONG_LENGTH_MS:
431             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_SONG_LENGTH_MS_INFO;
432             if (value){
433                 little_endian_store_32(event, pos, btstack_atoi((char *)value));
434             } else {
435                 little_endian_store_32(event, pos, 0);
436             }
437             pos += 4;
438             break;
439         case AVRCP_MEDIA_ATTR_TRACK:
440             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TRACK_INFO;
441             if (value){
442                 event[pos++] = btstack_atoi((char *)value);
443             } else {
444                 event[pos++] = 0;
445             }
446             break;
447         case AVRCP_MEDIA_ATTR_TOTAL_NUM_ITEMS:
448             event[subevent_type_pos] = AVRCP_SUBEVENT_NOW_PLAYING_TOTAL_TRACKS_INFO;
449             if (value){
450                 event[pos++] = btstack_atoi((char *)value);
451             } else {
452                 event[pos++] = 0;
453             }
454             break;
455         default:
456             break;
457     }
458     event[data_len_pos] = pos - 2;
459     (*callback)(HCI_EVENT_PACKET, 0, event, pos);
460 }
461 
462 static void avrcp_controller_emit_operation_status(btstack_packet_handler_t callback, uint8_t subevent, uint16_t avrcp_cid, uint8_t ctype, uint8_t operation_id){
463     btstack_assert(callback != NULL);
464 
465     uint8_t event[7];
466     int pos = 0;
467     event[pos++] = HCI_EVENT_AVRCP_META;
468     event[pos++] = sizeof(event) - 2;
469     event[pos++] = subevent;
470     little_endian_store_16(event, pos, avrcp_cid);
471     pos += 2;
472     event[pos++] = ctype;
473     event[pos++] = operation_id;
474     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
475 }
476 
477 static void avrcp_parser_reset(avrcp_connection_t * connection){
478     connection->list_offset = 0;
479     connection->parser_attribute_header_pos = 0;
480     connection->controller_num_received_fragments = 0;
481     connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_HEADER;
482 }
483 
484 static void avrcp_parser_process_byte(uint8_t byte, avrcp_connection_t * connection, avrcp_command_type_t ctype){
485     uint16_t attribute_total_value_len;
486     uint32_t attribute_id;
487     switch(connection->parser_state){
488         case AVRCP_PARSER_GET_ATTRIBUTE_HEADER:
489             connection->parser_attribute_header[connection->parser_attribute_header_pos++] = byte;
490             connection->list_offset++;
491 
492             if (connection->parser_attribute_header_pos < AVRCP_ATTRIBUTE_HEADER_LEN) return;
493 
494             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
495             connection->attribute_value_len = btstack_min(attribute_total_value_len, AVRCP_MAX_ATTRIBUTE_SIZE);
496             if (connection->attribute_value_len > 0){
497                 // get ready for attribute value
498                 connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_VALUE;
499                 return;
500             }
501 
502             // emit empty attribute
503             attribute_id = big_endian_read_32(connection->parser_attribute_header, 0);
504             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);
505 
506             // done, see below
507             break;
508 
509         case AVRCP_PARSER_GET_ATTRIBUTE_VALUE:
510             connection->attribute_value[connection->attribute_value_offset++] = byte;
511             connection->list_offset++;
512 
513             if (connection->attribute_value_offset < connection->attribute_value_len) return;
514 
515             // emit (potentially partial) attribute
516             attribute_id = big_endian_read_32(connection->parser_attribute_header, 0);
517             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);
518 
519             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
520             if (connection->attribute_value_offset < attribute_total_value_len){
521                 // ignore rest of attribute
522                 connection->parser_state = AVRCP_PARSER_IGNORE_REST_OF_ATTRIBUTE_VALUE;
523                 return;
524             }
525 
526             // done, see below
527             break;
528 
529         case AVRCP_PARSER_IGNORE_REST_OF_ATTRIBUTE_VALUE:
530             connection->attribute_value_offset++;
531             connection->list_offset++;
532 
533             attribute_total_value_len = big_endian_read_16(connection->parser_attribute_header, 6);
534             if (connection->attribute_value_offset < attribute_total_value_len) return;
535 
536             // done, see below
537             break;
538 
539         default:
540             return;
541     }
542 
543     // attribute fully read, check if more to come
544     if (connection->list_offset < connection->list_size){
545         // more to come, reset parser
546         connection->parser_state = AVRCP_PARSER_GET_ATTRIBUTE_HEADER;
547         connection->parser_attribute_header_pos = 0;
548         connection->attribute_value_offset = 0;
549     } else {
550         // fully done
551         avrcp_parser_reset(connection);
552         avrcp_controller_emit_now_playing_info_event_done(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, 0);
553     }
554 }
555 
556 static void avrcp_controller_parse_and_emit_element_attrs(uint8_t * packet, uint16_t num_bytes_to_read, avrcp_connection_t * connection, avrcp_command_type_t ctype){
557     int i;
558     for (i=0;i<num_bytes_to_read;i++){
559         avrcp_parser_process_byte(packet[i], connection, ctype);
560     }
561 }
562 
563 static void avrcp_send_cmd_with_avctp_fragmentation(avrcp_connection_t * connection){
564     l2cap_reserve_packet_buffer();
565     uint8_t * packet = l2cap_get_outgoing_buffer();
566 
567     uint16_t max_payload_size;
568     connection->avctp_packet_type = avctp_get_packet_type(connection, &max_payload_size);
569     connection->avrcp_packet_type = avrcp_get_packet_type(connection);
570 
571     // non-fragmented: transport header (1) + PID (2)
572     // fragmented:     transport header (1) + num packets (1) + PID (2)
573 
574     uint16_t param_len = connection->data_len;
575     // AVCTP header
576     // transport header : transaction label | Packet_type | C/R | IPID (1 == invalid profile identifier)
577     uint16_t pos = 0;
578     packet[pos++] = (connection->transaction_id << 4) | (connection->avctp_packet_type << 2) | (AVRCP_COMMAND_FRAME << 1) | 0;
579 
580     if (connection->avctp_packet_type == AVCTP_START_PACKET){
581         uint16_t max_frame_size = btstack_min(connection->l2cap_mtu, AVRCP_MAX_AV_C_MESSAGE_FRAME_SIZE);
582         // first packet: max_payload_size
583         // rest packets
584         uint16_t num_payload_bytes = param_len - max_payload_size;
585         uint16_t frame_size_for_continue_packet = max_frame_size - avctp_get_num_bytes_for_header(AVCTP_CONTINUE_PACKET);
586         uint16_t num_avctp_packets = (num_payload_bytes + frame_size_for_continue_packet - 1)/frame_size_for_continue_packet + 1;
587 		btstack_assert(num_avctp_packets <= 255);
588         packet[pos++] = (uint8_t) num_avctp_packets;
589     }
590 
591     switch (connection->avctp_packet_type){
592         case AVCTP_SINGLE_PACKET:
593         case AVCTP_START_PACKET:
594             connection->data_offset = 0;
595             // Profile IDentifier (PID)
596             packet[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL >> 8;
597             packet[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL & 0x00FF;
598 
599             // command_type
600             packet[pos++] = connection->command_type;
601             // subunit_type | subunit ID
602             packet[pos++] = (connection->subunit_type << 3) | connection->subunit_id;
603             // opcode
604             packet[pos++] = (uint8_t)connection->command_opcode;
605 
606             switch (connection->command_opcode){
607                 case AVRCP_CMD_OPCODE_VENDOR_DEPENDENT:
608                     big_endian_store_24(packet, pos, connection->company_id);
609                     pos += 3;
610                     packet[pos++] = connection->pdu_id;
611                     packet[pos++] = connection->avrcp_packet_type;              // reserved(upper 6) | AVRCP packet_type
612                     big_endian_store_16(packet, pos, connection->data_len);     // parameter length
613                     pos += 2;
614                     break;
615                 case AVRCP_CMD_OPCODE_PASS_THROUGH:
616                     packet[pos++] = connection->operation_id;
617                     packet[pos++] = (uint8_t)connection->data_len;     // parameter length
618                     pos += 2;
619                     break;
620                 case AVRCP_CMD_OPCODE_UNIT_INFO:
621                     break;
622                 case AVRCP_CMD_OPCODE_SUBUNIT_INFO:
623                     break;
624                 default:
625                     btstack_assert(false);
626                     return;
627             }
628             break;
629         case AVCTP_CONTINUE_PACKET:
630         case AVCTP_END_PACKET:
631             break;
632         default:
633             btstack_assert(false);
634             return;
635     }
636     // compare number of bytes to store with the remaining buffer size
637     uint16_t bytes_to_copy = btstack_min(connection->data_len - connection->data_offset, max_payload_size - pos);
638 
639     (void)memcpy(packet + pos, &connection->data[connection->data_offset], bytes_to_copy);
640     pos += bytes_to_copy;
641     connection->data_offset += bytes_to_copy;
642 
643     l2cap_send_prepared(connection->l2cap_signaling_cid, pos);
644 }
645 
646 static int avrcp_send_register_notification(avrcp_connection_t * connection, uint8_t event_id){
647     uint8_t command[18];
648     uint16_t pos = 0;
649     // transport header : transaction label | Packet_type | C/R | IPID (1 == invalid profile identifier)
650     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
651     command[pos++] = (connection->transaction_id << 4) | (AVRCP_SINGLE_PACKET << 2) | (AVRCP_COMMAND_FRAME << 1) | 0;
652 
653     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL >> 8;
654     command[pos++] = BLUETOOTH_SERVICE_CLASS_AV_REMOTE_CONTROL & 0x00FF;
655     command[pos++] = AVRCP_CTYPE_NOTIFY;
656     command[pos++] = (AVRCP_SUBUNIT_TYPE_PANEL << 3) | AVRCP_SUBUNIT_ID;
657     command[pos++] = AVRCP_CMD_OPCODE_VENDOR_DEPENDENT;
658 
659     big_endian_store_24(command, pos, BT_SIG_COMPANY_ID);
660     pos += 3;
661     command[pos++] = AVRCP_PDU_ID_REGISTER_NOTIFICATION;
662     command[pos++] = 0;                       // reserved(upper 6) | packet_type -> 0
663     big_endian_store_16(command, pos, 5);     // parameter length
664     pos += 2;
665     command[pos++] = event_id;
666     big_endian_store_32(command, pos, 1);     // send notification on playback position every second, for other notifications it is ignored
667     pos += 4;
668     return l2cap_send(connection->l2cap_signaling_cid, command, pos);
669 }
670 
671 static void avrcp_press_and_hold_timeout_handler(btstack_timer_source_t * timer){
672     UNUSED(timer);
673     avrcp_connection_t * connection = (avrcp_connection_t*) btstack_run_loop_get_timer_context(timer);
674     btstack_run_loop_set_timer(&connection->controller_press_and_hold_cmd_timer, 2000); // 2 seconds timeout
675     btstack_run_loop_add_timer(&connection->controller_press_and_hold_cmd_timer);
676     connection->state = AVCTP_W2_SEND_PRESS_COMMAND;
677     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
678 }
679 
680 static void avrcp_press_and_hold_timer_start(avrcp_connection_t * connection){
681     btstack_run_loop_remove_timer(&connection->controller_press_and_hold_cmd_timer);
682     btstack_run_loop_set_timer_handler(&connection->controller_press_and_hold_cmd_timer, avrcp_press_and_hold_timeout_handler);
683     btstack_run_loop_set_timer_context(&connection->controller_press_and_hold_cmd_timer, connection);
684     btstack_run_loop_set_timer(&connection->controller_press_and_hold_cmd_timer, 2000); // 2 seconds timeout
685     btstack_run_loop_add_timer(&connection->controller_press_and_hold_cmd_timer);
686 }
687 
688 static void avrcp_press_and_hold_timer_stop(avrcp_connection_t * connection){
689     connection->controller_press_and_hold_cmd_active = false;
690     btstack_run_loop_remove_timer(&connection->controller_press_and_hold_cmd_timer);
691 }
692 
693 
694 static uint8_t avrcp_controller_request_pass_through_release_control_cmd(avrcp_connection_t * connection){
695     connection->state = AVCTP_W2_SEND_RELEASE_COMMAND;
696     if (connection->controller_press_and_hold_cmd_active){
697         avrcp_press_and_hold_timer_stop(connection);
698     }
699     connection->operation_id = (avrcp_operation_id_t)(0x80 | connection->operation_id);
700     connection->transaction_id = avrcp_controller_get_next_transaction_label(connection);
701     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
702     return ERROR_CODE_SUCCESS;
703 }
704 
705 static uint8_t avrcp_controller_request_pass_through_press_control_cmd(uint16_t avrcp_cid, avrcp_operation_id_t opid, uint16_t playback_speed, bool continuous_cmd){
706 	UNUSED(playback_speed);
707 
708 	log_info("Send command %d", opid);
709     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
710     if (!connection){
711         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
712     }
713 
714     if (connection->state != AVCTP_CONNECTION_OPENED){
715         log_error("Connection in wrong state %d, expected %d. avrcp cid 0x%02x", connection->state, AVCTP_CONNECTION_OPENED, avrcp_cid);
716         return ERROR_CODE_COMMAND_DISALLOWED;
717     }
718     connection->state = AVCTP_W2_SEND_PRESS_COMMAND;
719     avrcp_controller_pass_through_command_data_init(connection, opid);
720 
721     connection->controller_press_and_hold_cmd_active = continuous_cmd;
722     if (connection->controller_press_and_hold_cmd_active){
723         avrcp_press_and_hold_timer_start(connection);
724     }
725 
726     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
727     return ERROR_CODE_SUCCESS;
728 }
729 
730 static uint8_t request_single_pass_through_press_control_cmd(uint16_t avrcp_cid, avrcp_operation_id_t opid, uint16_t playback_speed){
731     return avrcp_controller_request_pass_through_press_control_cmd(avrcp_cid, opid, playback_speed, false);
732 }
733 
734 static uint8_t request_continuous_pass_through_press_control_cmd(uint16_t avrcp_cid, avrcp_operation_id_t opid, uint16_t playback_speed){
735     return avrcp_controller_request_pass_through_press_control_cmd(avrcp_cid, opid, playback_speed, true);
736 }
737 
738 static void avrcp_controller_get_capabilities_for_connection(avrcp_connection_t * connection, uint8_t capability_id){
739     connection->state = AVCTP_W2_SEND_COMMAND;
740     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_STATUS, AVRCP_PDU_ID_GET_CAPABILITIES, true);
741 
742     // Parameter Length
743     connection->data_len = 1;
744     connection->data[0] = capability_id;  // capability ID
745 
746     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
747 }
748 
749 static uint8_t avrcp_controller_register_notification(avrcp_connection_t * connection, avrcp_notification_event_id_t event_id){
750     if ((connection->remote_capabilities_state == AVRCP_REMOTE_CAPABILITIES_KNOWN) && (connection->notifications_supported_by_target & (1 << event_id)) == 0){
751         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
752     }
753     if ((connection->controller_notifications_to_deregister & (1 << event_id)) != 0){
754         return ERROR_CODE_COMMAND_DISALLOWED;
755     }
756     if ( (connection->notifications_enabled & (1 << event_id)) != 0){
757         return ERROR_CODE_SUCCESS;
758     }
759     connection->controller_notifications_to_register |= (1 << event_id);
760 
761     switch (connection->remote_capabilities_state){
762         case AVRCP_REMOTE_CAPABILITIES_NONE:
763             connection->remote_capabilities_state = AVRCP_REMOTE_CAPABILITIES_W4_QUERY_RESULT;
764             connection->controller_notifications_supported_by_target_suppress_emit_result = true;
765             avrcp_controller_get_capabilities_for_connection(connection, AVRCP_CAPABILITY_ID_EVENT);
766             break;
767         case AVRCP_REMOTE_CAPABILITIES_KNOWN:
768             avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
769             break;
770         default:
771             break;
772     }
773     return ERROR_CODE_SUCCESS;
774 }
775 
776 static uint8_t avrcp_controller_request_continuation(avrcp_connection_t * connection, avrcp_pdu_id_t pdu_id){
777     connection->state = AVCTP_W2_SEND_COMMAND;
778     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, pdu_id, false);
779 
780     // Parameter Length
781     connection->data_len = 3;
782     big_endian_store_16(connection->data, 0, 1);
783     connection->data[2] = AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES;
784 
785     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
786     return ERROR_CODE_SUCCESS;
787 }
788 
789 static uint8_t avrcp_controller_request_abort_continuation(avrcp_connection_t * connection){
790     return avrcp_controller_request_continuation(connection, AVRCP_PDU_ID_REQUEST_ABORT_CONTINUING_RESPONSE);
791 }
792 
793 static uint8_t avrcp_controller_request_continue_response(avrcp_connection_t * connection){
794     return avrcp_controller_request_continuation(connection, AVRCP_PDU_ID_REQUEST_CONTINUING_RESPONSE);
795 }
796 
797 static void avrcp_controller_handle_notification(avrcp_connection_t *connection, avrcp_command_type_t ctype, uint8_t *payload, uint16_t size) {
798     if (size < 1) return;
799     uint16_t pos = 0;
800     avrcp_notification_event_id_t event_id = (avrcp_notification_event_id_t) payload[pos++];
801     if ( (event_id < AVRCP_NOTIFICATION_EVENT_FIRST_INDEX) || (event_id > AVRCP_NOTIFICATION_EVENT_LAST_INDEX)){
802         return;
803     }
804 
805     uint16_t event_mask = (1 << event_id);
806     uint16_t reset_event_mask = ~event_mask;
807 
808     switch (ctype){
809         case AVRCP_CTYPE_RESPONSE_REJECTED:
810             connection->controller_notifications_to_deregister &= reset_event_mask;
811             connection->controller_notifications_to_register   &= reset_event_mask;
812             connection->controller_initial_status_reported     &= reset_event_mask;
813             avrcp_controller_emit_notification_complete(connection, ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE, event_id, false);
814             return;
815 
816         case AVRCP_CTYPE_RESPONSE_INTERIM:
817             // register as enabled
818             connection->notifications_enabled |= event_mask;
819 
820             // check if initial value is already sent
821             if ((connection->controller_initial_status_reported & event_mask) != 0 ){
822                 return;
823             }
824             // emit event only once, initially
825             avrcp_controller_emit_notification_complete(connection, ERROR_CODE_SUCCESS, event_id, true);
826             connection->controller_initial_status_reported |= event_mask;
827             // emit initial value after this switch
828             break;
829 
830         case AVRCP_CTYPE_RESPONSE_CHANGED_STABLE:
831             // received change, event is considered de-registered
832             // we are re-enabling it automatically, if it is not
833             // explicitly disabled
834             connection->notifications_enabled &= reset_event_mask;
835             if ((connection->controller_notifications_to_deregister & event_mask) == 0){
836                 avrcp_controller_register_notification(connection, event_id);
837             } else {
838                 connection->controller_notifications_to_deregister &= reset_event_mask;
839                 connection->controller_notifications_to_register   &= reset_event_mask;
840                 connection->controller_initial_status_reported     &= reset_event_mask;
841                 avrcp_controller_emit_notification_complete(connection, ERROR_CODE_SUCCESS, event_id, false);
842             }
843             break;
844 
845         default:
846             return;
847     }
848 
849     avrcp_controller_emit_notification_for_event_id(connection->avrcp_cid, event_id, ctype, payload + pos, size - pos);
850 }
851 
852 #ifdef ENABLE_AVCTP_FRAGMENTATION
853 static void avctp_reassemble_message(avrcp_connection_t * connection, avctp_packet_type_t packet_type, uint8_t *packet, uint16_t size){
854     // after header (transaction label and packet type)
855     uint16_t pos;
856     uint16_t bytes_to_store;
857 
858     switch (packet_type){
859         case AVCTP_START_PACKET:
860             if (size < 2) return;
861 
862             // store header
863             pos = 0;
864             connection->avctp_reassembly_buffer[pos] = packet[pos];
865             pos++;
866             connection->avctp_reassembly_size = pos;
867 
868             // NOTE: num packets not needed for reassembly, ignoring it does not pose security risk -> no need to store it
869             pos++;
870 
871             // PID in reassembled packet is at offset 1, it will be read later after the avctp_reassemble_message with AVCTP_END_PACKET is called
872 
873             bytes_to_store = btstack_min(size - pos, sizeof(connection->avctp_reassembly_buffer) - connection->avctp_reassembly_size);
874             memcpy(&connection->avctp_reassembly_buffer[connection->avctp_reassembly_size], &packet[pos], bytes_to_store);
875             connection->avctp_reassembly_size += bytes_to_store;
876             break;
877 
878         case AVCTP_CONTINUE_PACKET:
879         case AVCTP_END_PACKET:
880             if (size < 1) return;
881 
882             // store remaining data, ignore header
883             pos = 1;
884             bytes_to_store = btstack_min(size - pos, sizeof(connection->avctp_reassembly_buffer) - connection->avctp_reassembly_size);
885             memcpy(&connection->avctp_reassembly_buffer[connection->avctp_reassembly_size], &packet[pos], bytes_to_store);
886             connection->avctp_reassembly_size += bytes_to_store;
887             break;
888 
889         default:
890             return;
891     }
892 }
893 #endif
894 
895 static void avrcp_handle_l2cap_data_packet_for_signaling_connection(avrcp_connection_t * connection, uint8_t *packet, uint16_t size){
896     if (size < 6u) return;
897     uint8_t  pdu_id;
898     avrcp_packet_type_t  vendor_dependent_avrcp_packet_type;
899 
900     uint16_t pos = 0;
901     connection->controller_last_confirmed_transaction_id = packet[pos] >> 4;
902     avrcp_frame_type_t  frame_type =  (avrcp_frame_type_t)((packet[pos] >> 1) & 0x01);
903     avctp_packet_type_t packet_type = (avctp_packet_type_t)((packet[pos] >> 2) & 0x03);
904     pos++;
905 
906     if (frame_type != AVRCP_RESPONSE_FRAME) return;
907 
908     switch (packet_type){
909         case AVCTP_SINGLE_PACKET:
910             break;
911 
912 #ifdef ENABLE_AVCTP_FRAGMENTATION
913         case AVCTP_START_PACKET:
914         case AVCTP_CONTINUE_PACKET:
915             avctp_reassemble_message(connection, packet_type, packet, size);
916             return;
917 
918         case AVCTP_END_PACKET:
919             avctp_reassemble_message(connection, packet_type, packet, size);
920 
921             packet = connection->avctp_reassembly_buffer;
922             size   = connection->avctp_reassembly_size;
923             break;
924 #endif
925 
926         default:
927             return;
928     }
929 
930     pos += 2; // PID
931 
932     avrcp_command_type_t ctype = (avrcp_command_type_t) packet[pos++];
933 
934 #ifdef ENABLE_LOG_INFO
935     uint8_t byte_value = packet[pos];
936     avrcp_subunit_type_t subunit_type = (avrcp_subunit_type_t) (byte_value >> 3);
937     avrcp_subunit_type_t subunit_id   = (avrcp_subunit_type_t) (byte_value & 0x07);
938 #endif
939     pos++;
940 
941     uint8_t opcode = packet[pos++];
942     uint16_t param_length;
943 
944     switch (opcode){
945         case AVRCP_CMD_OPCODE_SUBUNIT_INFO:{
946             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE) return;
947             connection->state = AVCTP_CONNECTION_OPENED;
948 
949 #ifdef ENABLE_LOG_INFO
950             // page, extension code (1)
951             pos++;
952             uint8_t unit_type = packet[pos] >> 3;
953             uint8_t max_subunit_ID = packet[pos] & 0x07;
954             log_info("SUBUNIT INFO response: ctype 0x%02x (0C), subunit_type 0x%02x (1F), subunit_id 0x%02x (07), opcode 0x%02x (30), target_unit_type 0x%02x, max_subunit_ID %d", ctype, subunit_type, subunit_id, opcode, unit_type, max_subunit_ID);
955 #endif
956             break;
957         }
958         case AVRCP_CMD_OPCODE_UNIT_INFO:{
959             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE) return;
960             connection->state = AVCTP_CONNECTION_OPENED;
961 
962 #ifdef ENABLE_LOG_INFO
963             // byte value 7 (1)
964             pos++;
965             uint8_t unit_type = packet[pos] >> 3;
966             uint8_t unit = packet[pos] & 0x07;
967             pos++;
968             uint32_t company_id = big_endian_read_24(packet, pos);
969             log_info("UNIT INFO response: ctype 0x%02x (0C), subunit_type 0x%02x (1F), subunit_id 0x%02x (07), opcode 0x%02x (30), target_unit_type 0x%02x, unit %d, company_id 0x%06" PRIx32,
970                 ctype, subunit_type, subunit_id, opcode, unit_type, unit, company_id);
971 #endif
972             break;
973         }
974         case AVRCP_CMD_OPCODE_VENDOR_DEPENDENT:
975             if ((size - pos) < 7){
976                 return;
977             }
978             // Company ID (3)
979             pos += 3;
980             pdu_id = packet[pos++];
981             vendor_dependent_avrcp_packet_type = (avrcp_packet_type_t)(packet[pos++] & 0x03);
982             param_length = big_endian_read_16(packet, pos);
983             pos += 2;
984 
985             if ((size - pos) < param_length) {
986                 return;
987             }
988 
989             // handle asynchronous notifications, without changing state
990             if (pdu_id == AVRCP_PDU_ID_REGISTER_NOTIFICATION){
991                 avrcp_controller_handle_notification(connection, ctype, packet + pos, size - pos);
992                 break;
993             }
994             if (connection->state != AVCTP_W2_RECEIVE_RESPONSE) return;
995             connection->state = AVCTP_CONNECTION_OPENED;
996 
997             log_info("VENDOR DEPENDENT response: pdu id 0x%02x, param_length %d, status %s", pdu_id, param_length, avrcp_ctype2str(ctype));
998             switch (pdu_id){
999                 case AVRCP_PDU_ID_GET_CURRENT_PLAYER_APPLICATION_SETTING_VALUE:{
1000                     uint8_t num_attributes = packet[pos++];
1001                     int i;
1002                     avrcp_repeat_mode_t  repeat_mode =  AVRCP_REPEAT_MODE_INVALID;
1003                     avrcp_shuffle_mode_t shuffle_mode = AVRCP_SHUFFLE_MODE_INVALID;
1004                     for (i = 0; i < num_attributes; i++){
1005                         uint8_t attribute_id    = packet[pos++];
1006                         uint8_t value = packet[pos++];
1007                         switch (attribute_id){
1008                             case 0x02:
1009                                 repeat_mode = (avrcp_repeat_mode_t) value;
1010                                 break;
1011                             case 0x03:
1012                                 shuffle_mode = (avrcp_shuffle_mode_t) value;
1013                                 break;
1014                             default:
1015                                 break;
1016                         }
1017                     }
1018                     avrcp_controller_emit_repeat_and_shuffle_mode(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, repeat_mode, shuffle_mode);
1019                     break;
1020                 }
1021 
1022                 case AVRCP_PDU_ID_SET_PLAYER_APPLICATION_SETTING_VALUE:{
1023                     uint16_t offset = 0;
1024                     uint8_t event[6];
1025                     event[offset++] = HCI_EVENT_AVRCP_META;
1026                     event[offset++] = sizeof(event) - 2;
1027                     event[offset++] = AVRCP_SUBEVENT_PLAYER_APPLICATION_VALUE_RESPONSE;
1028                     little_endian_store_16(event, offset, connection->avrcp_cid);
1029                     offset += 2;
1030                     event[offset++] = ctype;
1031                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
1032                     break;
1033                 }
1034 
1035                 case AVRCP_PDU_ID_SET_ABSOLUTE_VOLUME:{
1036                     uint16_t offset = 0;
1037                     uint8_t event[7];
1038                     event[offset++] = HCI_EVENT_AVRCP_META;
1039                     event[offset++] = sizeof(event) - 2;
1040                     event[offset++] = AVRCP_SUBEVENT_SET_ABSOLUTE_VOLUME_RESPONSE;
1041                     little_endian_store_16(event, offset, connection->avrcp_cid);
1042                     offset += 2;
1043                     event[offset++] = ctype;
1044                     event[offset++] = packet[pos++];
1045                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
1046                     break;
1047                 }
1048 
1049                 case AVRCP_PDU_ID_GET_CAPABILITIES:{
1050                     avrcp_capability_id_t capability_id = (avrcp_capability_id_t) packet[pos++];
1051                     uint8_t capability_count = 0;
1052                     if (param_length > 1){
1053                         capability_count = packet[pos++];
1054                     }
1055                     uint16_t i;
1056                     uint16_t offset;
1057                     uint8_t event[10];
1058 
1059                     switch (capability_id){
1060 
1061                         case AVRCP_CAPABILITY_ID_COMPANY:
1062                             for (i = 0; (i < capability_count) && ((size - pos) >= 3); i++){
1063                                 uint32_t company_id = big_endian_read_24(packet, pos);
1064                                 pos += 3;
1065                                 log_info("  0x%06" PRIx32 ", ", company_id);
1066 
1067                                 offset = 0;
1068                                 event[offset++] = HCI_EVENT_AVRCP_META;
1069                                 event[offset++] = sizeof(event) - 2;
1070                                 event[offset++] = AVRCP_SUBEVENT_GET_CAPABILITY_COMPANY_ID;
1071                                 little_endian_store_16(event, offset, connection->avrcp_cid);
1072                                 offset += 2;
1073                                 event[offset++] = ctype;
1074                                 event[offset++] = 0;
1075                                 little_endian_store_24(event, offset, company_id);
1076                                 offset += 3;
1077                                 (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, offset);
1078                             }
1079 
1080                             offset = 0;
1081                             event[offset++] = HCI_EVENT_AVRCP_META;
1082                             event[offset++] = sizeof(event) - 2;
1083                             event[offset++] = AVRCP_SUBEVENT_GET_CAPABILITY_COMPANY_ID_DONE;
1084                             little_endian_store_16(event, offset, connection->avrcp_cid);
1085                             offset += 2;
1086                             event[offset++] = ctype;
1087                             event[offset++] = 0;
1088                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, offset);
1089                             break;
1090 
1091                         case AVRCP_CAPABILITY_ID_EVENT:
1092                             for (i = 0; (i < capability_count) && ((size - pos) >= 1); i++){
1093                                 uint8_t event_id = packet[pos++];
1094                                 connection->notifications_supported_by_target |= (1 << event_id);
1095                             }
1096 
1097                             connection->remote_capabilities_state = AVRCP_REMOTE_CAPABILITIES_KNOWN;
1098 
1099                             // if the get supported events query is triggered by avrcp_controller_enable_notification call,
1100                             // avrcp_controller_emit_supported_events should be suppressed
1101                             if (connection->controller_notifications_supported_by_target_suppress_emit_result){
1102                                 connection->controller_notifications_supported_by_target_suppress_emit_result = false;
1103                                 // also, notification might not be supported
1104                                 // if so, emit AVRCP_SUBEVENT_ENABLE_NOTIFICATION_COMPLETE event to app,
1105                                 // and update controller_notifications_to_register bitmap
1106                                 for (i = (uint8_t)AVRCP_NOTIFICATION_EVENT_FIRST_INDEX; i < (uint8_t) AVRCP_NOTIFICATION_EVENT_LAST_INDEX; i++){
1107                                     if ((connection->controller_notifications_to_register & (1 << i)) != 0){
1108                                         if ((connection->notifications_supported_by_target & (1 << i)) == 0){
1109                                             avrcp_controller_emit_notification_complete(connection, ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE, (uint8_t) i, false);
1110                                             connection->controller_notifications_to_register &= ~(1 << i);
1111                                         }
1112                                     }
1113                                 }
1114                                 break;
1115                             }
1116                             // supported events are emitted only if the get supported events query
1117                             // is triggered by avrcp_controller_get_supported_events call
1118                             avrcp_controller_emit_supported_events(connection);
1119                             break;
1120 
1121                         default:
1122                             // ignore
1123                             break;
1124                     }
1125                     break;
1126                 }
1127 
1128                 case AVRCP_PDU_ID_GET_PLAY_STATUS:{
1129                     uint32_t song_length = big_endian_read_32(packet, pos);
1130                     pos += 4;
1131                     uint32_t song_position = big_endian_read_32(packet, pos);
1132                     pos += 4;
1133                     uint8_t play_status = packet[pos];
1134 
1135                     uint8_t event[15];
1136                     int offset = 0;
1137                     event[offset++] = HCI_EVENT_AVRCP_META;
1138                     event[offset++] = sizeof(event) - 2;
1139                     event[offset++] = AVRCP_SUBEVENT_PLAY_STATUS;
1140                     little_endian_store_16(event, offset, connection->avrcp_cid);
1141                     offset += 2;
1142                     event[offset++] = ctype;
1143                     little_endian_store_32(event, offset, song_length);
1144                     offset += 4;
1145                     little_endian_store_32(event, offset, song_position);
1146                     offset += 4;
1147                     event[offset++] = play_status;
1148                     (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
1149                     break;
1150                 }
1151 
1152                 case AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES:
1153                     switch (vendor_dependent_avrcp_packet_type){
1154                         case AVRCP_START_PACKET:
1155                         case AVRCP_SINGLE_PACKET:
1156                             avrcp_parser_reset(connection);
1157                             connection->list_size = param_length;
1158                             // num_attributes
1159                             pos++;
1160 
1161                             avrcp_controller_parse_and_emit_element_attrs(packet+pos, size-pos, connection, ctype);
1162                             if (vendor_dependent_avrcp_packet_type == AVRCP_START_PACKET){
1163                                 avrcp_controller_request_continue_response(connection);
1164                                 return;
1165                             }
1166                             break;
1167                         case AVRCP_CONTINUE_PACKET:
1168                         case AVRCP_END_PACKET:
1169                             connection->controller_num_received_fragments++;
1170 
1171                             if (connection->controller_num_received_fragments < connection->controller_max_num_fragments){
1172                                 avrcp_controller_parse_and_emit_element_attrs(packet+pos, size-pos, connection, ctype);
1173 
1174                                 if (vendor_dependent_avrcp_packet_type == AVRCP_CONTINUE_PACKET){
1175                                     avrcp_controller_request_continue_response(connection);
1176                                     return;
1177                                 }
1178                             } else {
1179                                 avrcp_controller_emit_now_playing_info_event_done(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, 1);
1180                                 avrcp_parser_reset(connection);
1181                                 avrcp_controller_request_abort_continuation(connection);
1182                                 return;
1183                             }
1184                             break;
1185                         default:
1186                             btstack_assert(false);
1187                             break;
1188                     }
1189                     break;
1190 
1191                 default:
1192                     // custom command response comes here
1193                     switch (pdu_id){
1194                         case AVRCP_PDU_ID_REQUEST_ABORT_CONTINUING_RESPONSE:
1195                             avrcp_controller_emit_now_playing_info_event_done(avrcp_controller_context.avrcp_callback, connection->avrcp_cid, ctype, 0);
1196                             break;
1197                         default:
1198                             if (pdu_id != connection->pdu_id) {
1199                                 break;
1200                             }
1201                             uint8_t *in_place_buffer = packet + pos - 9;
1202                             avrcp_controller_prepare_custom_command_response(connection, param_length,
1203                                                                              in_place_buffer);
1204                             (*avrcp_controller_context.avrcp_callback)(HCI_EVENT_PACKET, 0, in_place_buffer,
1205                                                                        param_length + 9);
1206 
1207                             break;
1208                     }
1209                     break;
1210             }
1211             break;
1212         case AVRCP_CMD_OPCODE_PASS_THROUGH:{
1213             if ((size - pos) < 1) return;
1214             uint8_t operation_id = packet[pos++];
1215             UNUSED(pos);
1216             switch (connection->state){
1217                 case AVCTP_W2_RECEIVE_PRESS_RESPONSE:
1218                     // trigger release for simple command:
1219                     if (!connection->controller_press_and_hold_cmd_active){
1220                         connection->state = AVCTP_W2_SEND_RELEASE_COMMAND;
1221                         break;
1222                     }
1223                     // for press and hold, send release if it just has been requested, otherwise, wait for next repeat
1224                     if (connection->controller_press_and_hold_cmd_release){
1225                         connection->controller_press_and_hold_cmd_release = false;
1226                         connection->state = AVCTP_W2_SEND_RELEASE_COMMAND;
1227                     } else {
1228                         connection->state = AVCTP_W4_STOP;
1229                     }
1230                     break;
1231                 case AVCTP_W2_RECEIVE_RESPONSE:
1232                     connection->state = AVCTP_CONNECTION_OPENED;
1233                     break;
1234                 default:
1235                     break;
1236             }
1237             if (connection->state == AVCTP_W4_STOP){
1238                 avrcp_controller_emit_operation_status(avrcp_controller_context.avrcp_callback, AVRCP_SUBEVENT_OPERATION_START, connection->avrcp_cid, ctype, operation_id);
1239             }
1240             if (connection->state == AVCTP_CONNECTION_OPENED) {
1241                 // RELEASE response
1242                 operation_id = operation_id & 0x7F;
1243                 avrcp_controller_emit_operation_status(avrcp_controller_context.avrcp_callback, AVRCP_SUBEVENT_OPERATION_COMPLETE, connection->avrcp_cid, ctype, operation_id);
1244             }
1245             if (connection->state == AVCTP_W2_SEND_RELEASE_COMMAND){
1246                 // PRESS response
1247                 avrcp_controller_request_pass_through_release_control_cmd(connection);
1248             }
1249             break;
1250         }
1251         default:
1252             break;
1253     }
1254 
1255     // trigger pending notification reqistrations
1256     if ((connection->state == AVCTP_CONNECTION_OPENED) && connection->controller_notifications_to_register){
1257         avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1258     }
1259 }
1260 
1261 static void avrcp_controller_handle_can_send_now(avrcp_connection_t * connection){
1262     // identifier (9) + num attributes (1) + attributes (4 * num attributes)
1263     uint8_t get_element_attributes_command[9+8*((AVRCP_MEDIA_ATTR_RESERVED-AVRCP_MEDIA_ATTR_TITLE) + 1)];
1264     uint16_t pos;
1265     uint16_t num_attributes_index;
1266     uint8_t i;
1267 
1268     switch (connection->state){
1269         case AVCTP_W2_SEND_PRESS_COMMAND:
1270             avrcp_send_cmd_with_avctp_fragmentation(connection);
1271             connection->state = AVCTP_W2_RECEIVE_PRESS_RESPONSE;
1272             return;
1273 
1274         case AVCTP_W2_SEND_RELEASE_COMMAND:
1275             avrcp_send_cmd_with_avctp_fragmentation(connection);
1276             connection->state = AVCTP_W2_RECEIVE_RESPONSE;
1277             return;
1278 
1279         case AVCTP_W2_SEND_COMMAND:
1280             avrcp_send_cmd_with_avctp_fragmentation(connection);
1281             if (connection->data_offset < connection->data_len){
1282                 // continue AVCTP fragmentation
1283                 avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1284                 return;
1285             }
1286             connection->state = AVCTP_W2_RECEIVE_RESPONSE;
1287             return;
1288         case AVCTP_W2_SEND_GET_ELEMENT_ATTRIBUTES_REQUEST:
1289             // build command in local buffer
1290             pos = 0;
1291             connection->data = get_element_attributes_command;
1292             // write identifier
1293             memset(connection->data, 0, 8);
1294             pos += 8;
1295             num_attributes_index = pos;
1296             // If num_attributes is set to zero, all attribute information shall be returned,
1297             // and the AttributeID field is omitted
1298             connection->data[num_attributes_index] = 0;
1299             pos++;
1300             for (i = 0; i < (uint8_t)AVRCP_MEDIA_ATTR_RESERVED - (uint8_t)AVRCP_MEDIA_ATTR_TITLE; i++){
1301                 if ((connection->controller_element_attributes & (1<<i)) != 0){
1302                     // every attribute is 4 bytes long
1303                     big_endian_store_32(connection->data, pos, AVRCP_MEDIA_ATTR_TITLE + i);
1304                     pos += 4;
1305                     connection->data[num_attributes_index]++;
1306                 }
1307             }
1308 
1309             // Parameter Length
1310             connection->data_len = pos;
1311 
1312             log_info("AVCTP_W2_SEND_GET_ELEMENT_ATTRIBUTES_REQUEST, len %u", connection->data_len);
1313 
1314             // send data - assume it will fit into one packet
1315             avrcp_send_cmd_with_avctp_fragmentation(connection);
1316             connection->state = AVCTP_W2_RECEIVE_RESPONSE;
1317             return;
1318         default:
1319             break;
1320     }
1321 
1322     // send register notification if queued,
1323     // avrcp_handle_l2cap_data_packet_for_signaling_connection will trigger next one
1324     if (connection->controller_notifications_to_register != 0){
1325         uint8_t event_id;
1326         for (event_id = (uint8_t)AVRCP_NOTIFICATION_EVENT_FIRST_INDEX; event_id < (uint8_t)AVRCP_NOTIFICATION_EVENT_LAST_INDEX; event_id++){
1327             if (connection->controller_notifications_to_register & (1 << event_id)){
1328                 connection->controller_notifications_to_register &= ~ (1 << event_id);
1329                 avrcp_send_register_notification(connection, event_id);
1330                 return;
1331             }
1332         }
1333     }
1334 }
1335 
1336 static void avrcp_controller_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
1337     avrcp_connection_t * connection;
1338 
1339     switch (packet_type) {
1340         case L2CAP_DATA_PACKET:
1341             connection = avrcp_get_connection_for_l2cap_signaling_cid_for_role(AVRCP_CONTROLLER, channel);
1342             avrcp_handle_l2cap_data_packet_for_signaling_connection(connection, packet, size);
1343             break;
1344 
1345         case HCI_EVENT_PACKET:
1346             switch (hci_event_packet_get_type(packet)){
1347                 case L2CAP_EVENT_CAN_SEND_NOW:
1348                     connection = avrcp_get_connection_for_l2cap_signaling_cid_for_role(AVRCP_CONTROLLER, channel);
1349                     avrcp_controller_handle_can_send_now(connection);
1350                     break;
1351             default:
1352                 break;
1353         }
1354         default:
1355             break;
1356     }
1357 }
1358 
1359 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){
1360     if (service_name == NULL){
1361         service_name = avrcp_default_controller_service_name;
1362     }
1363     if (service_provider_name == NULL){
1364         service_provider_name = avrcp_default_controller_service_provider_name;
1365     }
1366     avrcp_create_sdp_record(true, service, service_record_handle, avrcp_controller_supports_browsing(supported_features), supported_features, service_name, service_provider_name);
1367 }
1368 
1369 void avrcp_controller_init(void){
1370     avrcp_controller_context.role = AVRCP_CONTROLLER;
1371     avrcp_controller_context.packet_handler = avrcp_controller_packet_handler;
1372     avrcp_register_controller_packet_handler(&avrcp_controller_packet_handler);
1373 }
1374 
1375 void avrcp_controller_deinit(void){
1376     memset(&avrcp_controller_context, 0, sizeof(avrcp_context_t));
1377 }
1378 
1379 void avrcp_controller_register_packet_handler(btstack_packet_handler_t callback){
1380     btstack_assert(callback != NULL);
1381     avrcp_controller_context.avrcp_callback = callback;
1382 }
1383 
1384 
1385 uint8_t avrcp_controller_play(uint16_t avrcp_cid){
1386     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PLAY, 0);
1387 }
1388 
1389 uint8_t avrcp_controller_stop(uint16_t avrcp_cid){
1390     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_STOP, 0);
1391 }
1392 
1393 uint8_t avrcp_controller_pause(uint16_t avrcp_cid){
1394     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PAUSE, 0);
1395 }
1396 
1397 uint8_t avrcp_controller_forward(uint16_t avrcp_cid){
1398     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FORWARD, 0);
1399 }
1400 
1401 uint8_t avrcp_controller_backward(uint16_t avrcp_cid){
1402     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_BACKWARD, 0);
1403 }
1404 
1405 uint8_t avrcp_controller_volume_up(uint16_t avrcp_cid){
1406     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_UP, 0);
1407 }
1408 
1409 uint8_t avrcp_controller_volume_down(uint16_t avrcp_cid){
1410     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_DOWN, 0);
1411 }
1412 
1413 uint8_t avrcp_controller_mute(uint16_t avrcp_cid){
1414     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_MUTE, 0);
1415 }
1416 
1417 uint8_t avrcp_controller_skip(uint16_t avrcp_cid){
1418     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_SKIP, 0);
1419 }
1420 
1421 uint8_t avrcp_controller_fast_forward(uint16_t avrcp_cid){
1422     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FAST_FORWARD, 0);
1423 }
1424 
1425 uint8_t avrcp_controller_rewind(uint16_t avrcp_cid){
1426     return request_single_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_REWIND, 0);
1427 }
1428 
1429 /* start continuous cmds */
1430 
1431 uint8_t avrcp_controller_start_press_and_hold_cmd(uint16_t avrcp_cid, avrcp_operation_id_t operation_id){
1432     return request_continuous_pass_through_press_control_cmd(avrcp_cid, operation_id, 0);
1433 }
1434 
1435 uint8_t avrcp_controller_press_and_hold_play(uint16_t avrcp_cid){
1436     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PLAY, 0);
1437 }
1438 uint8_t avrcp_controller_press_and_hold_stop(uint16_t avrcp_cid){
1439     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_STOP, 0);
1440 }
1441 uint8_t avrcp_controller_press_and_hold_pause(uint16_t avrcp_cid){
1442     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_PAUSE, 0);
1443 }
1444 uint8_t avrcp_controller_press_and_hold_forward(uint16_t avrcp_cid){
1445     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FORWARD, 0);
1446 }
1447 uint8_t avrcp_controller_press_and_hold_backward(uint16_t avrcp_cid){
1448     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_BACKWARD, 0);
1449 }
1450 uint8_t avrcp_controller_press_and_hold_fast_forward(uint16_t avrcp_cid){
1451     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_FAST_FORWARD, 0);
1452 }
1453 uint8_t avrcp_controller_press_and_hold_rewind(uint16_t avrcp_cid){
1454     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_REWIND, 0);
1455 }
1456 uint8_t avrcp_controller_press_and_hold_volume_up(uint16_t avrcp_cid){
1457     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_UP, 0);
1458 }
1459 uint8_t avrcp_controller_press_and_hold_volume_down(uint16_t avrcp_cid){
1460     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_VOLUME_DOWN, 0);
1461 }
1462 uint8_t avrcp_controller_press_and_hold_mute(uint16_t avrcp_cid){
1463     return request_continuous_pass_through_press_control_cmd(avrcp_cid, AVRCP_OPERATION_ID_MUTE, 0);
1464 }
1465 
1466 /* stop continuous cmds */
1467 uint8_t avrcp_controller_release_press_and_hold_cmd(uint16_t avrcp_cid){
1468     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1469     if (!connection){
1470         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1471     }
1472 
1473     switch (connection->state){
1474         // respond when we receive response for (repeated) press command
1475         case AVCTP_W2_RECEIVE_PRESS_RESPONSE:
1476             connection->controller_press_and_hold_cmd_release = true;
1477             break;
1478 
1479         // release already sent or on the way, nothing to do
1480         case AVCTP_W2_RECEIVE_RESPONSE:
1481         case AVCTP_W2_SEND_RELEASE_COMMAND:
1482             break;
1483 
1484         // about to send next repeated press command or wait for it -> release right away
1485         case AVCTP_W2_SEND_PRESS_COMMAND:
1486         case AVCTP_W4_STOP:
1487             return avrcp_controller_request_pass_through_release_control_cmd(connection);
1488 
1489         // otherwise reject request
1490         default:
1491             return ERROR_CODE_COMMAND_DISALLOWED;
1492     }
1493     return ERROR_CODE_SUCCESS;
1494 }
1495 
1496 uint8_t avrcp_controller_enable_notification(uint16_t avrcp_cid, avrcp_notification_event_id_t event_id){
1497     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1498     if (!connection){
1499         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1500     }
1501     return avrcp_controller_register_notification(connection, event_id);
1502 }
1503 
1504 uint8_t avrcp_controller_disable_notification(uint16_t avrcp_cid, avrcp_notification_event_id_t event_id){
1505     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1506     if (!connection){
1507         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1508     }
1509     if (connection->remote_capabilities_state != AVRCP_REMOTE_CAPABILITIES_KNOWN){
1510         return ERROR_CODE_COMMAND_DISALLOWED;
1511     }
1512 
1513     if ((connection->notifications_supported_by_target & (1 << event_id)) == 0){
1514         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
1515     }
1516 
1517     if ((connection->notifications_enabled & (1 << event_id)) == 0){
1518         return ERROR_CODE_SUCCESS;
1519     }
1520 
1521     connection->controller_notifications_to_deregister |= (1 << event_id);
1522     return ERROR_CODE_SUCCESS;
1523 }
1524 
1525 uint8_t avrcp_controller_unit_info(uint16_t avrcp_cid){
1526     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1527     if (!connection){
1528         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1529     }
1530     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1531 
1532     connection->state = AVCTP_W2_SEND_COMMAND;
1533     avrcp_controller_custom_command_data_init(connection, AVRCP_CMD_OPCODE_UNIT_INFO, AVRCP_CTYPE_STATUS,
1534                                               AVRCP_SUBUNIT_TYPE_UNIT, AVRCP_SUBUNIT_ID_IGNORE, AVRCP_PDU_ID_UNDEFINED,
1535                                               0);
1536 
1537     connection->data = connection->message_body;
1538     memset(connection->data, 0xFF, 5);
1539     connection->data_len = 5;
1540     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1541     return ERROR_CODE_SUCCESS;
1542 }
1543 
1544 uint8_t avrcp_controller_subunit_info(uint16_t avrcp_cid){
1545     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1546     if (!connection){
1547         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1548     }
1549     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1550 
1551     connection->state = AVCTP_W2_SEND_COMMAND;
1552     avrcp_controller_custom_command_data_init(connection, AVRCP_CMD_OPCODE_SUBUNIT_INFO, AVRCP_CTYPE_STATUS,
1553                                               AVRCP_SUBUNIT_TYPE_UNIT, AVRCP_SUBUNIT_ID_IGNORE, AVRCP_PDU_ID_UNDEFINED,
1554                                               0);
1555 
1556     connection->data = connection->message_body;
1557     memset(connection->data, 0xFF, 5);
1558     connection->data[0] = 7; // page: 0, extension_code: 7
1559     connection->data_len = 5;
1560     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1561     return ERROR_CODE_SUCCESS;
1562 }
1563 
1564 uint8_t avrcp_controller_get_supported_company_ids(uint16_t avrcp_cid){
1565     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1566     if (!connection){
1567         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1568     }
1569     if (connection->state != AVCTP_CONNECTION_OPENED){
1570         return ERROR_CODE_COMMAND_DISALLOWED;
1571     }
1572     avrcp_controller_get_capabilities_for_connection(connection, AVRCP_CAPABILITY_ID_COMPANY);
1573     return ERROR_CODE_SUCCESS;
1574 }
1575 
1576 uint8_t avrcp_controller_get_supported_events(uint16_t avrcp_cid){
1577     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1578     if (!connection){
1579         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1580     }
1581     if (connection->state != AVCTP_CONNECTION_OPENED){
1582         return ERROR_CODE_COMMAND_DISALLOWED;
1583     }
1584 
1585     switch (connection->remote_capabilities_state){
1586         case AVRCP_REMOTE_CAPABILITIES_NONE:
1587             connection->remote_capabilities_state = AVRCP_REMOTE_CAPABILITIES_W4_QUERY_RESULT;
1588             avrcp_controller_get_capabilities_for_connection(connection, AVRCP_CAPABILITY_ID_EVENT);
1589             break;
1590         case AVRCP_REMOTE_CAPABILITIES_KNOWN:
1591             avrcp_controller_emit_supported_events(connection);
1592             break;
1593         default:
1594             break;
1595     }
1596     return ERROR_CODE_SUCCESS;
1597 }
1598 
1599 uint8_t avrcp_controller_get_play_status(uint16_t avrcp_cid){
1600     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1601     if (!connection){
1602         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1603     }
1604     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1605 
1606     connection->state = AVCTP_W2_SEND_COMMAND;
1607     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_STATUS, AVRCP_PDU_ID_GET_PLAY_STATUS, true);
1608 
1609     connection->data_len = 0;
1610     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1611     return ERROR_CODE_SUCCESS;
1612 }
1613 
1614 uint8_t avrcp_controller_set_addressed_player(uint16_t avrcp_cid, uint16_t addressed_player_id){
1615     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1616     if (!connection){
1617         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1618     }
1619     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1620 
1621     connection->state = AVCTP_W2_SEND_COMMAND;
1622     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, AVRCP_PDU_ID_SET_ADDRESSED_PLAYER, true);
1623 
1624     connection->data_len = 2;
1625     big_endian_store_16(connection->data, 0, addressed_player_id);
1626 
1627     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1628     return ERROR_CODE_SUCCESS;
1629 }
1630 
1631 uint8_t avrcp_controller_get_element_attributes(uint16_t avrcp_cid, uint8_t num_attributes, avrcp_media_attribute_id_t * attributes){
1632     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1633     if (!connection){
1634         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1635     }
1636 
1637     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1638 
1639     if (num_attributes >= AVRCP_MEDIA_ATTR_RESERVED) {
1640         return ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS;
1641     }
1642 
1643     connection->state = AVCTP_W2_SEND_GET_ELEMENT_ATTRIBUTES_REQUEST;
1644     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_STATUS, AVRCP_PDU_ID_GET_ELEMENT_ATTRIBUTES, true);
1645 
1646     // collect element attributes
1647     uint8_t i;
1648     uint16_t attributes_set = 0;
1649     for (i = 0; i < num_attributes; i++){
1650         // ignore invalid attribute ID and "get all attributes"
1651         if (AVRCP_MEDIA_ATTR_ALL < attributes[i] && attributes[i] < AVRCP_MEDIA_ATTR_RESERVED){
1652             attributes_set |= 1 << (attributes[i] - AVRCP_MEDIA_ATTR_TITLE);
1653         }
1654     }
1655     connection->controller_element_attributes = attributes_set;
1656 
1657     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1658     return ERROR_CODE_SUCCESS;
1659 }
1660 
1661 uint8_t avrcp_controller_get_now_playing_info(uint16_t avrcp_cid){
1662     return avrcp_controller_get_element_attributes(avrcp_cid, 0, NULL);
1663 }
1664 
1665 uint8_t avrcp_controller_get_now_playing_info_for_media_attribute_id(uint16_t avrcp_cid, avrcp_media_attribute_id_t media_attribute_id){
1666     if (media_attribute_id == AVRCP_MEDIA_ATTR_ALL){
1667         return avrcp_controller_get_now_playing_info(avrcp_cid);
1668     }
1669     avrcp_media_attribute_id_t media_attrs[1];
1670     media_attrs[0] = media_attribute_id;
1671     return avrcp_controller_get_element_attributes(avrcp_cid, 1, media_attrs);
1672 }
1673 
1674 uint8_t avrcp_controller_set_absolute_volume(uint16_t avrcp_cid, uint8_t volume){
1675      avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1676     if (!connection){
1677         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1678     }
1679 
1680     //
1681     // allow sending of multiple set abs volume commands without waiting for response
1682     //
1683     uint8_t status = ERROR_CODE_COMMAND_DISALLOWED;
1684     switch (connection->state){
1685         case AVCTP_CONNECTION_OPENED:
1686             status = ERROR_CODE_SUCCESS;
1687             break;
1688         case AVCTP_W2_RECEIVE_RESPONSE:
1689             // - is pending response also set abs volume
1690             if (connection->command_opcode  != AVRCP_CMD_OPCODE_VENDOR_DEPENDENT) break;
1691             if (connection->command_type    != AVRCP_CTYPE_CONTROL)               break;
1692             if (connection->subunit_type    != AVRCP_SUBUNIT_TYPE_PANEL)          break;
1693             if (connection->subunit_id      != AVRCP_SUBUNIT_ID)                  break;
1694             if (connection->pdu_id          != AVRCP_PDU_ID_SET_ABSOLUTE_VOLUME)  break;
1695             // - is next transaction id valid in window
1696             if (avrcp_controller_is_transaction_id_valid(connection, avrcp_controller_calc_next_transaction_label(connection->transaction_id_counter)) == false) break;
1697             status = ERROR_CODE_SUCCESS;
1698             break;
1699         default:
1700             break;
1701     }
1702     if (status != ERROR_CODE_SUCCESS) return status;
1703 
1704     connection->state = AVCTP_W2_SEND_COMMAND;
1705     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, AVRCP_PDU_ID_SET_ABSOLUTE_VOLUME, true);
1706 
1707     // Parameter Length
1708     connection->data_len = 1;
1709     connection->data[0] = volume;
1710 
1711     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1712     return ERROR_CODE_SUCCESS;
1713 }
1714 
1715 uint8_t avrcp_controller_query_shuffle_and_repeat_modes(uint16_t avrcp_cid){
1716     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1717     if (!connection){
1718         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1719     }
1720     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1721 
1722     connection->state = AVCTP_W2_SEND_COMMAND;
1723     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_STATUS, AVRCP_PDU_ID_GET_CURRENT_PLAYER_APPLICATION_SETTING_VALUE, true);
1724 
1725     connection->data_len = 5;
1726     connection->data[0] = 4;                     // NumPlayerApplicationSettingAttributeID
1727     // PlayerApplicationSettingAttributeID1 AVRCP Spec, Appendix F, 133
1728     connection->data[1] = 0x01;   // equalizer  (1-OFF, 2-ON)
1729     connection->data[2] = 0x02;   // repeat     (1-off, 2-single track, 3-all tracks, 4-group repeat)
1730     connection->data[3] = 0x03;   // shuffle    (1-off, 2-all tracks, 3-group shuffle)
1731     connection->data[4] = 0x04;   // scan       (1-off, 2-all tracks, 3-group scan)
1732 
1733     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1734     return ERROR_CODE_SUCCESS;
1735 }
1736 
1737 static uint8_t avrcp_controller_set_current_player_application_setting_value(uint16_t avrcp_cid, uint8_t attr_id, uint8_t attr_value){
1738     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1739     if (!connection){
1740         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1741     }
1742     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1743 
1744     connection->state = AVCTP_W2_SEND_COMMAND;
1745     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, AVRCP_PDU_ID_SET_PLAYER_APPLICATION_SETTING_VALUE, true);
1746 
1747     // Parameter Length
1748     connection->data_len = 3;
1749     connection->data[0]  = 2;
1750     connection->data[1]  = attr_id;
1751     connection->data[2]  = attr_value;
1752 
1753     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1754     return ERROR_CODE_SUCCESS;
1755 }
1756 
1757 uint8_t avrcp_controller_set_shuffle_mode(uint16_t avrcp_cid, avrcp_shuffle_mode_t mode){
1758     if ((mode < AVRCP_SHUFFLE_MODE_OFF) || (mode > AVRCP_SHUFFLE_MODE_GROUP)) return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
1759     return avrcp_controller_set_current_player_application_setting_value(avrcp_cid, 0x03, mode);
1760 }
1761 
1762 uint8_t avrcp_controller_set_repeat_mode(uint16_t avrcp_cid, avrcp_repeat_mode_t mode){
1763     if ((mode < AVRCP_REPEAT_MODE_OFF) || (mode > AVRCP_REPEAT_MODE_GROUP)) return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
1764     return avrcp_controller_set_current_player_application_setting_value(avrcp_cid, 0x02, mode);
1765 }
1766 
1767 uint8_t avrcp_controller_play_item_for_scope(uint16_t avrcp_cid, uint8_t * uid, uint16_t uid_counter, avrcp_browsing_scope_t scope){
1768     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1769     if (!connection){
1770         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1771     }
1772     if (connection->state != AVCTP_CONNECTION_OPENED){
1773         log_error("Connection in wrong state, expected %d, received %d", AVCTP_CONNECTION_OPENED, connection->state);
1774         return ERROR_CODE_COMMAND_DISALLOWED;
1775     }
1776     connection->state = AVCTP_W2_SEND_COMMAND;
1777     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, AVRCP_PDU_ID_PLAY_ITEM, true);
1778 
1779     // Parameter Length
1780     connection->data_len = 11;
1781     connection->data[0]  = scope;
1782     memset(&connection->data[1], 0, 8);
1783     if (uid){
1784         (void)memcpy(&connection->data[1], uid, 8);
1785     }
1786     big_endian_store_16(connection->data, 9, uid_counter);
1787 
1788     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1789     return ERROR_CODE_SUCCESS;
1790 }
1791 
1792 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){
1793     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1794     if (!connection){
1795         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1796     }
1797     if (connection->state != AVCTP_CONNECTION_OPENED){
1798         log_error("Connection in wrong state, expected %d, received %d", AVCTP_CONNECTION_OPENED, connection->state);
1799         return ERROR_CODE_COMMAND_DISALLOWED;
1800     }
1801 
1802     connection->state = AVCTP_W2_SEND_COMMAND;
1803     avrcp_controller_vendor_dependent_command_data_init(connection, AVRCP_CTYPE_CONTROL, AVRCP_PDU_ID_ADD_TO_NOW_PLAYING, true);
1804 
1805     // Parameter Length
1806     connection->data_len = 11;
1807     connection->data[0]  = scope;
1808     memset(&connection->data[1], 0, 8);
1809     if (uid){
1810         (void)memcpy(&connection->data[1], uid, 8);
1811     }
1812     big_endian_store_16(connection->data, 9, uid_counter);
1813 
1814     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1815     return ERROR_CODE_SUCCESS;
1816 }
1817 
1818 uint8_t avrcp_controller_set_max_num_fragments(uint16_t avrcp_cid, uint8_t max_num_fragments){
1819     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1820     if (!connection){
1821         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1822     }
1823     connection->controller_max_num_fragments = max_num_fragments;
1824     return ERROR_CODE_SUCCESS;
1825 }
1826 
1827 
1828 uint8_t avrcp_controller_send_custom_command(uint16_t avrcp_cid,
1829     avrcp_command_type_t command_type,
1830     avrcp_subunit_type_t subunit_type, avrcp_subunit_id_t subunit_id,
1831     avrcp_pdu_id_t pdu_id, uint32_t company_id,
1832     const uint8_t * data, uint16_t data_len){
1833 
1834     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1835     if (!connection){
1836         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1837     }
1838     if (connection->state != AVCTP_CONNECTION_OPENED) return ERROR_CODE_COMMAND_DISALLOWED;
1839 
1840     connection->state = AVCTP_W2_SEND_COMMAND;
1841     avrcp_controller_custom_command_data_init(connection, AVRCP_CMD_OPCODE_VENDOR_DEPENDENT, command_type, subunit_type,
1842                                               subunit_id, pdu_id, company_id);
1843 
1844     connection->data = (uint8_t *)data;
1845     connection->data_len = data_len;
1846 
1847     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1848     return ERROR_CODE_SUCCESS;
1849 }
1850 
1851 uint8_t avrcp_controller_force_send_press_cmd(uint16_t avrcp_cid, avrcp_operation_id_t opid){
1852     avrcp_connection_t * connection = avrcp_get_connection_for_avrcp_cid_for_role(AVRCP_CONTROLLER, avrcp_cid);
1853     if (!connection){
1854         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
1855     }
1856     if (connection->state < AVCTP_CONNECTION_OPENED){
1857         return ERROR_CODE_COMMAND_DISALLOWED;
1858     }
1859 
1860     connection->state = AVCTP_W2_SEND_COMMAND;
1861     avrcp_controller_pass_through_command_data_init(connection, opid);
1862     avrcp_request_can_send_now(connection, connection->l2cap_signaling_cid);
1863     return ERROR_CODE_SUCCESS;
1864 }