xref: /btstack/example/avrcp_browsing_client.c (revision 02d2f9ca1b1c19161ac9dd48ed2418a43dd0c49b)
1 /*
2  * Copyright (C) 2016 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
24  * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at
34  * [email protected]
35  *
36  */
37 
38 #define BTSTACK_FILE__ "avrcp_browsing_client.c"
39 
40 /*
41  * avrcp_browsing_client.c
42  */
43 
44 // *****************************************************************************
45 /* EXAMPLE_START(avrcp_browsing_client): Browse media players and media information on a remote device.
46  *
47  * @text This example demonstrates how to use the AVRCP Controller Browsing service to
48  * browse madia players and media information on a remote AVRCP Source device.
49  *
50  * @test To test with a remote device, e.g. a mobile phone,
51  * pair from the remote device with the demo, then use the UI for browsing (tap
52  * SPACE on the console to show the available AVRCP commands).
53  *
54  */
55 // *****************************************************************************
56 
57 #include <stdint.h>
58 #include <inttypes.h>
59 #include <stdio.h>
60 #include <stdlib.h>
61 #include <string.h>
62 
63 #include "btstack.h"
64 
65 #ifdef HAVE_BTSTACK_STDIN
66 #include "btstack_stdin.h"
67 #endif
68 
69 #define AVRCP_BROWSING_ENABLED
70 
71 #define AVRCP_BROWSING_MAX_PLAYERS          10
72 #define AVRCP_BROWSING_MAX_FOLDERS          10
73 #define AVRCP_BROWSING_MAX_FOLDER_NAME_LEN  30
74 
75 #ifdef HAVE_BTSTACK_STDIN
76 // mac 2011: static bd_addr_t remote = {0x04, 0x0C, 0xCE, 0xE4, 0x85, 0xD3};
77 // pts: static bd_addr_t remote = {0x00, 0x1B, 0xDC, 0x08, 0x0A, 0xA5};
78 // mac 2013:
79 // static const char * device_addr_string = "84:38:35:65:d1:15";
80 // iPhone 5S: static const char * device_addr_string = "54:E4:3A:26:A2:39";
81 // phone 2013:
82 // static const char * device_addr_string = "B0:34:95:CB:97:C4";
83 // iPod
84 static const char * device_addr_string = "B0:34:95:CB:97:C4";
85 
86 static bd_addr_t device_addr;
87 #endif
88 
89 static uint16_t avrcp_cid = 0;
90 static uint8_t  avrcp_connected = 0;
91 
92 static uint16_t browsing_cid = 0;
93 static uint8_t  avrcp_browsing_connected = 0;
94 static uint8_t  sdp_avrcp_browsing_controller_service_buffer[200];
95 
96 static uint8_t browsing_query_active = 0;
97 static avrcp_media_item_context_t media_item_context;
98 
99 typedef struct {
100     uint16_t  charset;
101     uint8_t   depth;
102     uint16_t  name_len;
103     char      name[AVRCP_BROWSING_MAX_FOLDER_NAME_LEN];
104 } avrcp_browsing_root_folder_t;
105 
106 typedef struct {
107     uint8_t  uid[8];
108     uint16_t name_len;
109     char     name[AVRCP_BROWSING_MAX_FOLDER_NAME_LEN];
110 } avrcp_browsing_folders_t;
111 
112 static uint8_t  parent_folder_set = 0;
113 static uint8_t  parent_folder_uid[8];
114 static char     parent_folder_name[AVRCP_BROWSING_MAX_FOLDER_NAME_LEN];
115 static avrcp_browsing_folders_t folders[AVRCP_BROWSING_MAX_FOLDERS];
116 static int folder_index = -1;
117 static uint16_t players[AVRCP_BROWSING_MAX_PLAYERS];
118 static int player_index = -1;
119 static uint16_t browsing_uid_counter = 0;
120 
121 static btstack_packet_callback_registration_t hci_event_callback_registration;
122 
123 static uint8_t ertm_buffer[10000];
124 static l2cap_ertm_config_t ertm_config = {
125     1,  // ertm mandatory
126     2,  // max transmit, some tests require > 1
127     2000,
128     12000,
129     144,    // l2cap ertm mtu
130     4,
131     4,
132     0,      // No FCS
133 };
134 
135 static inline int next_index(int * index, int max_value){
136     if ((*index) < max_value){
137         (*index)++;
138     } else {
139         (*index) = 0;
140     }
141     return (*index);
142 }
143 
144 static int next_folder_index(void){
145     return next_index(&folder_index, AVRCP_BROWSING_MAX_FOLDERS);
146 }
147 
148 static int next_player_index(void){
149     return next_index(&player_index, AVRCP_BROWSING_MAX_PLAYERS);
150 }
151 
152 
153 /* @section Main Application Setup
154  *
155  * @text The Listing MainConfiguration shows how to setup AVRCP Controller Browsing service.
156  * To announce AVRCP Controller Browsing service, you need to create corresponding
157  * SDP record and register it with the SDP service.
158  * You'll also need to register several packet handlers:
159  * - stdin_process callback - used to trigger AVRCP commands, such are get media players, playlists, albums, etc. Requires HAVE_BTSTACK_STDIN.
160  * - avrcp_browsing_controller_packet_handler - used to receive answers for AVRCP commands.
161  *
162  */
163 
164 /* LISTING_START(MainConfiguration): Setup Audio Sink and AVRCP Controller services */
165 static void avrcp_browsing_controller_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
166 static void avrcp_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
167 
168 #ifdef HAVE_BTSTACK_STDIN
169 static void stdin_process(char cmd);
170 #endif
171 
172 
173 int btstack_main(int argc, const char * argv[]);
174 int btstack_main(int argc, const char * argv[]){
175     (void)argc;
176     (void)argv;
177 
178     // Initialize L2CAP.
179     l2cap_init();
180 
181     // Initialize AVRCP service.
182     avrcp_init();
183     // Initialize AVRCP Controller & Target Service.
184     avrcp_controller_init();
185     avrcp_target_init();
186 
187     avrcp_register_packet_handler(&avrcp_packet_handler);
188     avrcp_controller_register_packet_handler(&avrcp_packet_handler);
189     avrcp_target_register_packet_handler(&avrcp_packet_handler);
190 
191     // Initialize AVRCP Browsing Controller, HCI events will be sent to the AVRCP Controller callback.
192     avrcp_browsing_controller_init();
193     // // Register AVRCP for HCI events.
194     avrcp_browsing_controller_register_packet_handler(&avrcp_browsing_controller_packet_handler);
195 
196     // Initialize SDP.
197     sdp_init();
198 
199     // Create AVRCP service record and register it with SDP.
200     memset(sdp_avrcp_browsing_controller_service_buffer, 0, sizeof(sdp_avrcp_browsing_controller_service_buffer));
201 
202     uint16_t supported_features = (1 << AVRCP_CONTROLLER_SUPPORTED_FEATURE_CATEGORY_PLAYER_OR_RECORDER);
203 #ifdef AVRCP_BROWSING_ENABLED
204     supported_features |= (1 << AVRCP_CONTROLLER_SUPPORTED_FEATURE_BROWSING);
205 #endif
206     avrcp_controller_create_sdp_record(sdp_avrcp_browsing_controller_service_buffer, 0x10001, supported_features, NULL, NULL);
207     sdp_register_service(sdp_avrcp_browsing_controller_service_buffer);
208 
209     // Set local name with a template Bluetooth address, that will be automatically
210     // replaced with a actual address once it is available, i.e. when BTstack boots
211     // up and starts talking to a Bluetooth module.
212     gap_set_local_name("AVRCP Browsing Client 00:00:00:00:00:00");
213     gap_discoverable_control(1);
214     gap_set_class_of_device(0x200408);
215 
216     // Register for HCI events.
217     hci_event_callback_registration.callback = &avrcp_browsing_controller_packet_handler;
218     hci_add_event_handler(&hci_event_callback_registration);
219 
220     // Register for AVRCP events.
221     avrcp_controller_register_packet_handler(&avrcp_browsing_controller_packet_handler);
222 
223 
224 #ifdef HAVE_BTSTACK_STDIN
225     // Parse human readable Bluetooth address.
226     sscanf_bd_addr(device_addr_string, device_addr);
227     btstack_stdin_setup(stdin_process);
228 #endif
229     printf("Starting BTstack ...\n");
230     hci_power_control(HCI_POWER_ON);
231     return 0;
232 }
233 /* LISTING_END */
234 
235 static void avrcp_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
236     UNUSED(channel);
237     UNUSED(size);
238     uint16_t local_cid;
239     uint8_t  status = 0xFF;
240     bd_addr_t adress;
241 
242     if (packet_type != HCI_EVENT_PACKET) return;
243     if (hci_event_packet_get_type(packet) != HCI_EVENT_AVRCP_META) return;
244     switch (packet[2]){
245         case AVRCP_SUBEVENT_CONNECTION_ESTABLISHED: {
246             local_cid = avrcp_subevent_connection_established_get_avrcp_cid(packet);
247             status = avrcp_subevent_connection_established_get_status(packet);
248             if (status != ERROR_CODE_SUCCESS){
249                 printf("AVRCP: Connection failed: status 0x%02x\n", status);
250                 avrcp_cid = 0;
251                 return;
252             }
253 
254             avrcp_cid = local_cid;
255             avrcp_connected = 1;
256             avrcp_subevent_connection_established_get_bd_addr(packet, adress);
257             printf("AVRCP: Connected to %s, cid 0x%02x\n", bd_addr_to_str(adress), avrcp_cid);
258             return;
259         }
260 
261         case AVRCP_SUBEVENT_CONNECTION_RELEASED:
262             printf("AVRCP: Channel released: cid 0x%02x\n", avrcp_subevent_connection_released_get_avrcp_cid(packet));
263             avrcp_cid = 0;
264             avrcp_connected = 0;
265             return;
266         default:
267             break;
268     }
269 }
270 static void avrcp_browsing_controller_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
271     UNUSED(channel);
272     int pos;
273 
274     switch(packet_type){
275         case AVRCP_BROWSING_DATA_PACKET:
276             pos = 0;
277             browsing_query_active = 1;
278             avrcp_browsing_item_type_t data_type = (avrcp_browsing_item_type_t)packet[pos++];
279             pos += 2; // length
280 
281             switch (data_type){
282                 case AVRCP_BROWSING_MEDIA_ROOT_FOLDER:{
283                     avrcp_browsing_root_folder_t root_folder;
284                     root_folder.charset = big_endian_read_16(packet, pos);
285                     pos += 2;
286                     root_folder.depth = packet[pos++];
287                     root_folder.name_len = big_endian_read_16(packet, pos);
288                     pos += 2;
289 
290                     memset(root_folder.name, 0, AVRCP_BROWSING_MAX_FOLDER_NAME_LEN);
291                     root_folder.name_len = btstack_min(big_endian_read_16(packet, pos), AVRCP_BROWSING_MAX_FOLDER_NAME_LEN - 1);
292                     memcpy(root_folder.name, packet+pos, root_folder.name_len);
293                     printf("Found root folder: name %s, depth %d \n", (char *)root_folder.name, root_folder.depth);
294                     break;
295                 }
296                 case AVRCP_BROWSING_MEDIA_PLAYER_ITEM:{
297                     printf("Received media player:  ");
298                     uint16_t player_id = big_endian_read_16(packet, pos);
299                     pos += 2;
300                     avrcp_browsing_media_player_major_type_t major_type = packet[pos++];
301                     avrcp_browsing_media_player_subtype_t subtype = big_endian_read_32(packet, pos);
302                     pos += 4;
303                     uint8_t status = packet[pos++];
304                     uint8_t feature_bitmask[16];
305                     memcpy(feature_bitmask, packet, 16);
306                     pos += 16;
307                     printf("player ID 0x%04x, major_type %d, subtype %d, status %d\n", player_id, major_type, subtype, status);
308                     players[next_player_index()] = player_id;
309                     break;
310                 }
311                 case AVRCP_BROWSING_FOLDER_ITEM:{
312                     int index = next_folder_index();
313                     // printf("Found folder [%d]: ", index);
314                     memcpy(folders[index].uid, packet+pos, 8);
315                     uint32_t folder_uid_high = big_endian_read_32(packet, pos);
316                     pos += 4;
317                     uint32_t folder_uid_low  = big_endian_read_32(packet, pos);
318                     pos += 4;
319                     avrcp_browsing_folder_type_t folder_type = packet[pos++];
320                     uint8_t  is_playable = packet[pos++];
321                     uint16_t charset = big_endian_read_16(packet, pos);
322                     pos += 2;
323                     uint16_t displayable_name_length = big_endian_read_16(packet, pos);
324                     pos += 2;
325 
326                     char value[AVRCP_BROWSING_MAX_FOLDER_NAME_LEN];
327 
328                     memset(value, 0, AVRCP_BROWSING_MAX_FOLDER_NAME_LEN);
329                     uint16_t value_len = btstack_min(displayable_name_length, AVRCP_BROWSING_MAX_FOLDER_NAME_LEN - 1);
330                     memcpy(value, packet+pos, value_len);
331 
332                     printf("UID 0x%08" PRIx32 "%08" PRIx32 ", type 0x%02x, is_playable %d, charset 0x%02x, name %s\n",
333                         folder_uid_high, folder_uid_low, folder_type, is_playable, charset, value);
334                     memcpy(folders[index].name, value, value_len);
335                     folders[index].name_len = value_len;
336                     break;
337                 }
338                 case AVRCP_BROWSING_MEDIA_ELEMENT_ITEM:{
339                     printf("Found media: ");
340 
341                     uint32_t media_uid_high = big_endian_read_32(packet, pos);
342                     pos += 4;
343                     uint32_t media_uid_low  = big_endian_read_32(packet, pos+4);
344                     pos += 4;
345                     avrcp_browsing_media_type_t media_type = packet[pos++];
346                     uint16_t charset = big_endian_read_16(packet, pos);
347                     pos += 2;
348                     uint16_t displayable_name_length = big_endian_read_16(packet, pos);
349                     pos += 2;
350                     pos += displayable_name_length;
351                     printf("Media UID: 0x%08" PRIx32 "%08" PRIx32 ", media_type 0x%02x, charset 0x%02x, displayable_name_length %d\n", media_uid_high, media_uid_low, media_type, charset, displayable_name_length);
352 
353                     uint8_t num_attributes = packet[pos++];
354                     printf("Num media attributes %d\n", num_attributes);
355 
356                     for (avrcp_media_item_iterator_init(&media_item_context, size-pos, packet+pos); avrcp_media_item_iterator_has_more(&media_item_context); avrcp_media_item_iterator_next(&media_item_context)){
357                         uint32_t attr_id            = avrcp_media_item_iterator_get_attr_id(&media_item_context);
358                         uint16_t attr_charset       = avrcp_media_item_iterator_get_attr_charset(&media_item_context);
359                         uint16_t attr_value_length  = avrcp_media_item_iterator_get_attr_value_len(&media_item_context);
360                         const uint8_t * attr_value  = avrcp_media_item_iterator_get_attr_value(&media_item_context);
361 
362                         printf("Attr ID 0x%08" PRIx32 ", charset %d, attr_value_length %d, value %s", attr_id, attr_charset, attr_value_length, attr_value);
363                     }
364                     break;
365                 }
366 
367                 default:
368                     log_error("AVRCP browsing: unknown browsable item type 0%02x", data_type);
369                     break;
370             }
371             break;
372         case HCI_EVENT_PACKET:
373             if (hci_event_packet_get_type(packet) != HCI_EVENT_AVRCP_META) return;
374             uint16_t local_cid;
375             uint8_t  status = 0xFF;
376             bd_addr_t address;
377 
378             if (packet[0] != HCI_EVENT_AVRCP_META) break;
379             switch (packet[2]){
380 
381                 case AVRCP_SUBEVENT_INCOMING_BROWSING_CONNECTION:
382                     local_cid = avrcp_subevent_incoming_browsing_connection_get_browsing_cid(packet);
383                     printf("AVRCP_SUBEVENT_INCOMING_BROWSING_CONNECTION cid 0x%02x\n", local_cid);
384                     if (browsing_cid != 0 && browsing_cid != local_cid) {
385                         printf("AVRCP Browsing Client connection failed, expected 0x%02X l2cap cid, received 0x%02X\n", browsing_cid, local_cid);
386                         avrcp_browsing_controller_decline_incoming_connection(browsing_cid);
387                         return;
388                     }
389                     browsing_cid = local_cid;
390                     printf("AVRCP Browsing Client configure incoming connection, browsing cid 0x%02x\n", browsing_cid);
391                     avrcp_browsing_controller_configure_incoming_connection(browsing_cid, ertm_buffer, sizeof(ertm_buffer), &ertm_config);
392                     break;
393 
394                 case AVRCP_SUBEVENT_BROWSING_CONNECTION_ESTABLISHED: {
395                     local_cid = avrcp_subevent_browsing_connection_established_get_browsing_cid(packet);
396                     printf("AVRCP_SUBEVENT_BROWSING_CONNECTION_ESTABLISHED cid 0x%02x\n", local_cid);
397                     if (browsing_cid != 0 && browsing_cid != local_cid) {
398                         printf("AVRCP Browsing Client connection failed, expected 0x%02X l2cap cid, received 0x%02X\n", browsing_cid, local_cid);
399                         return;
400                     }
401 
402                     status = avrcp_subevent_browsing_connection_established_get_status(packet);
403                     if (status != ERROR_CODE_SUCCESS){
404                         printf("AVRCP Browsing Client connection failed: status 0x%02x\n", status);
405                         browsing_cid = 0;
406                         return;
407                     }
408 
409                     browsing_cid = local_cid;
410                     avrcp_browsing_connected = 1;
411                     avrcp_subevent_browsing_connection_established_get_bd_addr(packet, address);
412                     printf("AVRCP Browsing Client connected\n");
413                     return;
414                 }
415                 case AVRCP_SUBEVENT_BROWSING_CONNECTION_RELEASED:
416                     printf("AVRCP Browsing Controller released\n");
417                     browsing_cid = 0;
418                     avrcp_browsing_connected = 0;
419                     return;
420 
421                 case AVRCP_SUBEVENT_BROWSING_DONE:
422                     browsing_query_active = 0;
423                     browsing_uid_counter = 0;
424                     if (avrcp_subevent_browsing_done_get_browsing_status(packet) != AVRCP_BROWSING_ERROR_CODE_SUCCESS){
425                         printf("AVRCP Browsing query done with browsing status 0x%02x, bluetooth status 0x%02x.\n",
426                             avrcp_subevent_browsing_done_get_browsing_status(packet),
427                             avrcp_subevent_browsing_done_get_bluetooth_status(packet));
428                         break;
429                     }
430                     browsing_uid_counter = avrcp_subevent_browsing_done_get_uid_counter(packet);
431                     printf("DONE, browsing_uid_counter %d.\n", browsing_uid_counter);
432                     break;
433 
434                 default:
435                     break;
436             }
437             break;
438 
439         default:
440             break;
441     }
442 
443 }
444 
445 #ifdef HAVE_BTSTACK_STDIN
446 static void show_usage(void){
447     bd_addr_t      iut_address;
448     gap_local_bd_addr(iut_address);
449     printf("\n--- Bluetooth AVRCP Controller Connection Test Console %s ---\n", bd_addr_to_str(iut_address));
450     printf("c      - AVRCP create connection to addr %s\n", bd_addr_to_str(device_addr));
451     printf("C      - AVRCP disconnect\n");
452     printf("e      - AVRCP Browsing Controller create connection to addr %s\n", bd_addr_to_str(device_addr));
453     printf("E      - AVRCP Browsing Controller disconnect\n");
454 
455     printf("I      - Set first found player as addressed player\n");
456     printf("O      - Set first found player as browsed player\n");
457 
458     printf("p      - Get media players\n");
459     printf("Q      - Browse folders\n");
460     printf("P      - Go up one level\n");
461     printf("W      - Go down one level\n");
462     printf("T      - Browse media items\n");
463     printf("---\n");
464 }
465 #endif
466 
467 
468 #ifdef HAVE_BTSTACK_STDIN
469 static void stdin_process(char cmd){
470     uint8_t status = ERROR_CODE_SUCCESS;
471 
472     if (cmd != 'a' && cmd != 'A' && cmd != 'c' && cmd != 'C'){
473         if (browsing_query_active){
474             printf("Query active, try later!\n");
475             return;
476         }
477     }
478 
479     switch (cmd){
480         case 'c':
481             printf(" - Create AVRCP connection for control to addr %s.\n", bd_addr_to_str(device_addr));
482             status = avrcp_connect(device_addr, &avrcp_cid);
483             break;
484         case 'C':
485             if (avrcp_connected){
486                 printf(" - AVRCP disconnect from addr %s.\n", bd_addr_to_str(device_addr));
487                 status = avrcp_disconnect(avrcp_cid);
488                 break;
489             }
490             printf("AVRCP service already disconnected\n");
491             break;
492 
493         case 'e':
494             if (!avrcp_connected) {
495                 printf(" You must first create AVRCP connection for control to addr %s.\n", bd_addr_to_str(device_addr));
496                 break;
497             }
498             printf(" - Create AVRCP connection for browsing to addr %s.\n", bd_addr_to_str(device_addr));
499             status = avrcp_browsing_controller_connect(device_addr, ertm_buffer, sizeof(ertm_buffer), &ertm_config, &browsing_cid);
500             break;
501         case 'E':
502             if (avrcp_browsing_connected){
503                 printf(" - AVRCP Browsing Controller disconnect from addr %s.\n", bd_addr_to_str(device_addr));
504                 status = avrcp_browsing_controller_disconnect(browsing_cid);
505                 break;
506             }
507             printf("AVRCP Browsing Controller already disconnected\n");
508             break;
509         case '\n':
510         case '\r':
511             break;
512 
513         default:
514             if (!avrcp_browsing_connected){
515                 show_usage();
516                 printf("Please connect the AVRCP Browsing client\n");
517                 break;
518             }
519 
520             switch (cmd) {
521                 case 'I':
522                     if (player_index < 0) {
523                         printf("Get media players first\n");
524                         break;
525                     }
526                     printf("Set addressed player\n");
527                     status = avrcp_controller_set_addressed_player(avrcp_cid, players[0]);
528                     break;
529                 case 'O':
530                     if (player_index < 0) {
531                         printf("Get media players first\n");
532                         break;
533                     }
534                     printf("Set browsed player\n");
535                     status = avrcp_browsing_controller_set_browsed_player(browsing_cid, players[0]);
536                     break;
537                 case 'p':
538                     printf("AVRCP Browsing: get media players\n");
539                     player_index = -1;
540                     status = avrcp_browsing_controller_get_media_players(browsing_cid, 0, 0xFFFFFFFF, AVRCP_MEDIA_ATTR_ALL);
541                     break;
542                 case 'Q':
543                     printf("AVRCP Browsing: browse folders\n");
544                     folder_index = -1;
545                     status = avrcp_browsing_controller_browse_file_system(browsing_cid, 0, 0xFFFFFFFF, AVRCP_MEDIA_ATTR_ALL);
546                     break;
547                 case 'P':
548                     printf("AVRCP Browsing: browse media items\n");
549                     avrcp_browsing_controller_browse_media(browsing_cid, 0, 0xFFFFFFFF, AVRCP_MEDIA_ATTR_ALL);
550                     break;
551                 case 'W':
552                     printf("AVRCP Browsing: go up one level\n");
553                     status = avrcp_browsing_controller_go_up_one_level(browsing_cid);
554                     folder_index = -1;
555                     break;
556                 case 'T':
557                     if (folder_index < 0 && !parent_folder_set){
558                         printf("AVRCP Browsing: no folders available\n");
559                         break;
560                     }
561                     if (!parent_folder_set){
562                         parent_folder_set = 1;
563                         memcpy(parent_folder_name, folders[0].name, folders[0].name_len);
564                         memcpy(parent_folder_uid, folders[0].uid, 8);
565                     }
566                     printf("AVRCP Browsing: go down one level of %s\n", (char *)parent_folder_name);
567                     status = avrcp_browsing_controller_go_down_one_level(browsing_cid, parent_folder_uid);
568                     folder_index = -1;
569                     break;
570                 default:
571                     show_usage();
572                     break;
573             }
574             break;
575     }
576 
577     if (status != ERROR_CODE_SUCCESS){
578         printf("Could not perform command, status 0x%2x\n", status);
579     }
580 }
581 #endif
582 /* EXAMPLE_END */
583