aboutsummaryrefslogtreecommitdiff
path: root/stack/avrc/avrc_bld_ct.cc
blob: 4d85d17979c9cecc30ee386a0164827fed0bff2d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
/******************************************************************************
 *
 *  Copyright 2006-2013 Broadcom Corporation
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at:
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 ******************************************************************************/
#include <string.h>

#include "avrc_api.h"
#include "avrc_defs.h"
#include "avrc_int.h"
#include "bt_common.h"

/*****************************************************************************
 *  Global data
 ****************************************************************************/

/*******************************************************************************
 *
 * Function         avrc_bld_next_cmd
 *
 * Description      This function builds the Request Continue or Abort command.
 *
 * Returns          AVRC_STS_NO_ERROR, if the command is built successfully
 *                  Otherwise, the error code.
 *
 ******************************************************************************/
static tAVRC_STS avrc_bld_next_cmd(tAVRC_NEXT_CMD* p_cmd, BT_HDR* p_pkt) {
  uint8_t *p_data, *p_start;

  AVRC_TRACE_API("avrc_bld_next_cmd");

  /* get the existing length, if any, and also the num attributes */
  p_start = (uint8_t*)(p_pkt + 1) + p_pkt->offset;
  p_data = p_start + 2; /* pdu + rsvd */

  /* add fixed lenth 1 - pdu_id (1) */
  UINT16_TO_BE_STREAM(p_data, 1);
  UINT8_TO_BE_STREAM(p_data, p_cmd->target_pdu);
  p_pkt->len = (p_data - p_start);

  return AVRC_STS_NO_ERROR;
}

/*****************************************************************************
 *  the following commands are introduced in AVRCP 1.4
 ****************************************************************************/

#if (AVRC_ADV_CTRL_INCLUDED == TRUE)
/*******************************************************************************
 *
 * Function         avrc_bld_set_abs_volume_cmd
 *
 * Description      This function builds the Set Absolute Volume command.
 *
 * Returns          AVRC_STS_NO_ERROR, if the command is built successfully
 *                  Otherwise, the error code.
 *
 ******************************************************************************/
static tAVRC_STS avrc_bld_set_abs_volume_cmd(tAVRC_SET_VOLUME_CMD* p_cmd,
                                             BT_HDR* p_pkt) {
  uint8_t *p_data, *p_start;

  AVRC_TRACE_API("avrc_bld_set_abs_volume_cmd");
  /* get the existing length, if any, and also the num attributes */
  p_start = (uint8_t*)(p_pkt + 1) + p_pkt->offset;
  p_data = p_start + 2; /* pdu + rsvd */
  /* add fixed lenth 1 - volume (1) */
  UINT16_TO_BE_STREAM(p_data, 1);
  UINT8_TO_BE_STREAM(p_data, (AVRC_MAX_VOLUME & p_cmd->volume));
  p_pkt->len = (p_data - p_start);
  return AVRC_STS_NO_ERROR;
}

/*******************************************************************************
 *
 * Function         avrc_bld_register_notifn
 *
 * Description      This function builds the register notification.
 *
 * Returns          AVRC_STS_NO_ERROR, if the command is built successfully
 *                  Otherwise, the error code.
 *
 ******************************************************************************/
static tAVRC_STS avrc_bld_register_notifn(BT_HDR* p_pkt, uint8_t event_id,
                                          uint32_t event_param) {
  uint8_t *p_data, *p_start;

  AVRC_TRACE_API("avrc_bld_register_notifn");
  /* get the existing length, if any, and also the num attributes */
  // Set the notify value
  p_start = (uint8_t*)(p_pkt + 1) + p_pkt->offset;
  p_data = p_start + 2; /* pdu + rsvd */
  /* add fixed length 5 -*/
  UINT16_TO_BE_STREAM(p_data, 5);
  UINT8_TO_BE_STREAM(p_data, event_id);
  UINT32_TO_BE_STREAM(p_data, event_param);
  p_pkt->len = (p_data - p_start);
  return AVRC_STS_NO_ERROR;
}
#endif

/*******************************************************************************
 *
 * Function         avrc_bld_get_capability_cmd
 *
 * Description      This function builds the get capability command.
 *
 * Returns          AVRC_STS_NO_ERROR, if the command is built successfully
 *                  Otherwise, the error code.
 *
 ******************************************************************************/
static tAVRC_STS avrc_bld_get_capability_cmd(BT_HDR* p_pkt, uint8_t cap_id) {
  AVRC_TRACE_API("avrc_bld_get_capability_cmd");
  uint8_t* p_start = (uint8_t*)(p_pkt + 1) + p_pkt->offset;
  uint8_t* p_data = p_start + 2; /* pdu + rsvd */
  /* add fixed length 1 -*/
  UINT16_TO_BE_STREAM(p_data, 1);
  UINT8_TO_BE_STREAM(p_data, cap_id);
  p_pkt->len = (p_data - p_start);
  return AVRC_STS_NO_ERROR;
}

/*******************************************************************************
 *
 * Function         avrc_bld_list_player_app_attr_cmd
 *
 * Description      This function builds the list player app attrib command.
 *
 * Returns          AVRC_STS_NO_ERROR, if the command is built successfully
 *                  Otherwise, the error code.
 *
 ******************************************************************************/
static tAVRC_STS avrc_bld_list_player_app_attr_cmd(BT_HDR* p_pkt) {
  AVRC_TRACE_API("avrc_bld_list_player_app_attr_cmd");
  uint8_t* p_start = (uint8_t*)(p_pkt + 1) + p_pkt->offset;
  uint8_t* p_data = p_start + 2; /* pdu + rsvd */
  /* add fixed length 1 -*/
  UINT16_TO_BE_STREAM(p_data, 0);
  p_pkt->len = (p_data - p_start);
  return AVRC_STS_NO_ERROR;
}

/*******************************************************************************
 *
 * Function         avrc_bld_list_player_app_values_cmd
 *
 * Description      This function builds the list player app values command.
 *
 * Returns          AVRC_STS_NO_ERROR, if the command is built successfully
 *                  Otherwise, the error code.
 *
 ******************************************************************************/
static tAVRC_STS avrc_bld_list_player_app_values_cmd(BT_HDR* p_pkt,
                                                     uint8_t attrib_id) {
  AVRC_TRACE_API("avrc_bld_list_player_app_values_cmd");
  uint8_t* p_start = (uint8_t*)(p_pkt + 1) + p_pkt->offset;
  uint8_t* p_data = p_start + 2; /* pdu + rsvd */
  /* add fixed length 1 -*/
  UINT16_TO_BE_STREAM(p_data, 1);
  UINT8_TO_BE_STREAM(p_data, attrib_id);
  p_pkt->len = (p_data - p_start);
  return AVRC_STS_NO_ERROR;
}

/*******************************************************************************
 *
 * Function         avrc_bld_get_current_player_app_values_cmd
 *
 * Description      This function builds the get current player app setting
 *                  values command.
 *
 * Returns          AVRC_STS_NO_ERROR, if the command is built successfully
 *                  Otherwise, the error code.
 *
 ******************************************************************************/
static tAVRC_STS avrc_bld_get_current_player_app_values_cmd(
    BT_HDR* p_pkt, uint8_t num_attrib_id, uint8_t* attrib_ids) {
  AVRC_TRACE_API("avrc_bld_get_current_player_app_values_cmd");
  uint8_t* p_start = (uint8_t*)(p_pkt + 1) + p_pkt->offset;
  uint8_t* p_data = p_start + 2; /* pdu + rsvd */
  uint8_t param_len =
      num_attrib_id + 1;  // 1 additional to hold num attributes feild
  /* add length -*/
  UINT16_TO_BE_STREAM(p_data, param_len);
  UINT8_TO_BE_STREAM(p_data, num_attrib_id);
  for (int count = 0; count < num_attrib_id; count++) {
    UINT8_TO_BE_STREAM(p_data, attrib_ids[count]);
  }
  p_pkt->len = (p_data - p_start);
  return AVRC_STS_NO_ERROR;
}

/*******************************************************************************
 *
 * Function         avrc_bld_set_current_player_app_values_cmd
 *
 * Description      This function builds the set current player app setting
 *                  values command.
 *
 * Returns          AVRC_STS_NO_ERROR, if the command is built successfully
 *                  Otherwise, the error code.
 *
 ******************************************************************************/
static tAVRC_STS avrc_bld_set_current_player_app_values_cmd(
    BT_HDR* p_pkt, uint8_t num_attrib_id, tAVRC_APP_SETTING* p_val) {
  AVRC_TRACE_API("avrc_bld_set_current_player_app_values_cmd");
  uint8_t* p_start = (uint8_t*)(p_pkt + 1) + p_pkt->offset;
  uint8_t* p_data = p_start + 2; /* pdu + rsvd */
  /* we have to store attrib- value pair
   * 1 additional to store num elements
   */
  uint8_t param_len = (2 * num_attrib_id) + 1;
  /* add length */
  UINT16_TO_BE_STREAM(p_data, param_len);
  UINT8_TO_BE_STREAM(p_data, num_attrib_id);
  for (int count = 0; count < num_attrib_id; count++) {
    UINT8_TO_BE_STREAM(p_data, p_val[count].attr_id);
    UINT8_TO_BE_STREAM(p_data, p_val[count].attr_val);
  }
  p_pkt->len = (p_data - p_start);
  return AVRC_STS_NO_ERROR;
}

/*******************************************************************************
 *
 * Function         avrc_bld_get_player_app_setting_attr_text_cmd
 *
 * Description      This function builds the get player app setting attribute
 *                  text command.
 *
 * Returns          AVRC_STS_NO_ERROR, if the command is built successfully
 *                  Otherwise, the error code.
 *
 ******************************************************************************/
static tAVRC_STS avrc_bld_get_player_app_setting_attr_text_cmd(
    BT_HDR* p_pkt, tAVRC_GET_APP_ATTR_TXT_CMD* p_cmd) {
  AVRC_TRACE_API("%s", __func__);

  uint8_t* p_start = (uint8_t*)(p_pkt + 1) + p_pkt->offset;
  uint8_t* p_data = p_start + 2; /* pdu + rsvd */

  uint8_t param_len = p_cmd->num_attr + 1;
  /* add length */
  UINT16_TO_BE_STREAM(p_data, param_len);
  UINT8_TO_BE_STREAM(p_data, p_cmd->num_attr);
  for (int count = 0; count < p_cmd->num_attr; count++) {
    UINT8_TO_BE_STREAM(p_data, p_cmd->attrs[count]);
  }
  p_pkt->len = (p_data - p_start);
  return AVRC_STS_NO_ERROR;
}

/*******************************************************************************
 *
 * Function         avrc_bld_get_player_app_setting_value_text_cmd
 *
 * Description      This function builds the get player app setting value
 *                  text command.
 *
 * Returns          AVRC_STS_NO_ERROR, if the command is built successfully
 *                  Otherwise, the error code.
 *
 ******************************************************************************/
static tAVRC_STS avrc_bld_get_player_app_setting_value_text_cmd(
    BT_HDR* p_pkt, tAVRC_GET_APP_VAL_TXT_CMD* p_cmd) {
  AVRC_TRACE_API("%s", __func__);

  uint8_t* p_start = (uint8_t*)(p_pkt + 1) + p_pkt->offset;
  uint8_t* p_data = p_start + 2; /* pdu + rsvd */

  uint8_t param_len = p_cmd->num_val + 1;
  /* add length */
  UINT16_TO_BE_STREAM(p_data, param_len);
  UINT8_TO_BE_STREAM(p_data, p_cmd->num_val);
  for (int count = 0; count < p_cmd->num_val; count++) {
    UINT8_TO_BE_STREAM(p_data, p_cmd->vals[count]);
  }
  p_pkt->len = (p_data - p_start);
  return AVRC_STS_NO_ERROR;
}

/*******************************************************************************
 *
 * Function         avrc_bld_get_element_attr_cmd
 *
 * Description      This function builds the get element attribute command.
 *
 * Returns          AVRC_STS_NO_ERROR, if the command is built successfully
 *                  Otherwise, the error code.
 *
 ******************************************************************************/
static tAVRC_STS avrc_bld_get_element_attr_cmd(BT_HDR* p_pkt,
                                               uint8_t num_attrib,
                                               uint32_t* attrib_ids) {
  AVRC_TRACE_API("avrc_bld_get_element_attr_cmd");
  uint8_t* p_start = (uint8_t*)(p_pkt + 1) + p_pkt->offset;
  uint8_t* p_data = p_start + 2; /* pdu + rsvd */
  /* we have to store attrib- value pair
   * 1 additional to store num elements
   */
  uint8_t param_len = (4 * num_attrib) + 9;
  /* add length */
  UINT16_TO_BE_STREAM(p_data, param_len);
  /* 8 bytes of identifier as 0 (playing)*/
  UINT32_TO_BE_STREAM(p_data, 0);
  UINT32_TO_BE_STREAM(p_data, 0);
  UINT8_TO_BE_STREAM(p_data, num_attrib);
  for (int count = 0; count < num_attrib; count++) {
    UINT32_TO_BE_STREAM(p_data, attrib_ids[count]);
  }
  p_pkt->len = (p_data - p_start);
  return AVRC_STS_NO_ERROR;
}

/*******************************************************************************
 *
 * Function         avrc_bld_play_item_cmd
 *
 * Description      This function builds the play item cmd
 *
 * Returns          AVRC_STS_NO_ERROR, if the command is built successfully
 *                  Otherwise, the error code.
 *
 ******************************************************************************/
static tAVRC_STS avrc_bld_play_item_cmd(BT_HDR* p_pkt, uint8_t scope,
                                        uint8_t* uid, uint16_t uid_counter) {
  AVRC_TRACE_API("avrc_bld_get_element_attr_cmd");
  uint8_t* p_start = (uint8_t*)(p_pkt + 1) + p_pkt->offset;
  uint8_t* p_data = p_start + 2; /* pdu + rsvd */
  /* add fixed length 11 */
  UINT16_TO_BE_STREAM(p_data, 0xb);
  /* Add scope */
  UINT8_TO_BE_STREAM(p_data, scope);
  /* Add UID */
  ARRAY_TO_BE_STREAM(p_data, uid, AVRC_UID_SIZE);
  /* Add UID Counter */
  UINT16_TO_BE_STREAM(p_data, uid_counter);
  p_pkt->len = (p_data - p_start);
  return AVRC_STS_NO_ERROR;
}

/*******************************************************************************
 *
 * Function         avrc_bld_get_play_status_cmd
 *
 * Description      This function builds the get play status command.
 *
 * Returns          AVRC_STS_NO_ERROR, if the command is built successfully
 *                  Otherwise, the error code.
 *
 ******************************************************************************/
static tAVRC_STS avrc_bld_get_play_status_cmd(BT_HDR* p_pkt) {
  AVRC_TRACE_API("avrc_bld_list_player_app_attr_cmd");
  uint8_t* p_start = (uint8_t*)(p_pkt + 1) + p_pkt->offset;
  uint8_t* p_data = p_start + 2; /* pdu + rsvd */
  /* add fixed length 0 -*/
  UINT16_TO_BE_STREAM(p_data, 0);
  p_pkt->len = (p_data - p_start);
  return AVRC_STS_NO_ERROR;
}

/*******************************************************************************
 *
 * Function         avrc_bld_get_folder_items_cmd
 *
 * Description      This function builds the get folder items cmd.
 *
 * Returns          AVRC_STS_NO_ERROR, if the command is built successfully
 *                  Otherwise, the error code.
 *
 ******************************************************************************/
static tAVRC_STS avrc_bld_get_folder_items_cmd(BT_HDR* p_pkt,
                                               const tAVRC_GET_ITEMS_CMD* cmd) {
  AVRC_TRACE_API(
      "avrc_bld_get_folder_items_cmd scope %d, start_item %d, end_item %d",
      cmd->scope, cmd->start_item, cmd->end_item);
  uint8_t* p_start = (uint8_t*)(p_pkt + 1) + p_pkt->offset;
  /* This is where the PDU specific for AVRC starts
   * AVRCP Spec 1.4 section 22.19 */
  uint8_t* p_data = p_start + 1; /* pdu */

  /* To get the list of all media players we simply need to use the predefined
   * PDU mentioned in above spec. */
  /* scope (1) + st item (4) + end item (4) + attr (1) */
  UINT16_TO_BE_STREAM(p_data, 10);
  UINT8_TO_BE_STREAM(p_data, cmd->scope);       /* scope (1bytes) */
  UINT32_TO_BE_STREAM(p_data, cmd->start_item); /* start item (4bytes) */
  UINT32_TO_BE_STREAM(p_data, cmd->end_item);   /* end item (4bytes) */
  UINT8_TO_BE_STREAM(p_data, 0); /* attribute count = 0 (1bytes) */
  p_pkt->len = (p_data - p_start);
  return AVRC_STS_NO_ERROR;
}

/*******************************************************************************
 *
 * Function         avrc_bld_change_folder_cmd
 *
 * Description      This function builds the change folder command
 *
 * Returns          AVRC_STS_NO_ERROR, if the command is built successfully
 *                  Otherwise, the error code.
 *
 ******************************************************************************/
static tAVRC_STS avrc_bld_change_folder_cmd(BT_HDR* p_pkt,
                                            const tAVRC_CHG_PATH_CMD* cmd) {
  AVRC_TRACE_API("avrc_bld_change_folder_cmd");
  uint8_t* p_start = (uint8_t*)(p_pkt + 1) + p_pkt->offset;
  /* This is where the PDU specific for AVRC starts
   * AVRCP Spec 1.4 section 22.19 */
  uint8_t* p_data = p_start + 1; /* pdu */

  /* To change folder we need to provide the following:
   * UID Counter (2) + Direction (1) + UID (8) = 11bytes
   */
  UINT16_TO_BE_STREAM(p_data, 11);
  UINT16_TO_BE_STREAM(p_data, cmd->uid_counter);
  UINT8_TO_BE_STREAM(p_data, cmd->direction);
  ARRAY_TO_BE_STREAM(p_data, cmd->folder_uid, AVRC_UID_SIZE);
  p_pkt->len = (p_data - p_start);
  return AVRC_STS_NO_ERROR;
}
static tAVRC_STS avrc_bld_get_item_attributes_cmd(
    BT_HDR* p_pkt, const tAVRC_GET_ATTRS_CMD* cmd) {
  AVRC_TRACE_API("%s", __func__);
  uint8_t* p_start = (uint8_t*)(p_pkt + 1) + p_pkt->offset;
  /* This is where the PDU specific for AVRC starts
   * AVRCP Spec 1.4 section 22.19 */
  uint8_t* p_data = p_start + 1; /* pdu */
  UINT16_TO_BE_STREAM(p_data, 12 + 4 * cmd->attr_count);
  UINT8_TO_BE_STREAM(p_data, cmd->scope);
  uint64_t uid;
  memcpy(&uid, cmd->uid, 8);
  UINT64_TO_BE_STREAM(p_data, uid);
  UINT16_TO_BE_STREAM(p_data, cmd->uid_counter);
  UINT8_TO_BE_STREAM(p_data, cmd->attr_count);
  ARRAY_TO_BE_STREAM(p_data, cmd->p_attr_list, 4 * cmd->attr_count);
  p_pkt->len = (p_data - p_start);
  return AVRC_STS_NO_ERROR;
}
/*******************************************************************************
 *
 * Function         avrc_bld_set_browsed_player_cmd
 *
 * Description      This function builds the set browsed player cmd.
 *
 * Returns          AVRC_STS_NO_ERROR, if the command is built successfully
 *                  Otherwise, the error code.
 *
 ******************************************************************************/
static tAVRC_STS avrc_bld_set_browsed_player_cmd(
    BT_HDR* p_pkt, const tAVRC_SET_BR_PLAYER_CMD* cmd) {
  AVRC_TRACE_API("%s", __func__);
  uint8_t* p_start = (uint8_t*)(p_pkt + 1) + p_pkt->offset;
  /* This is where the PDU specific for AVRC starts
   * AVRCP Spec 1.4 section 22.19 */
  uint8_t* p_data = p_start + 1; /* pdu */

  /* To change browsed player the following is the total length:
   * Player ID (2)
   */
  UINT16_TO_BE_STREAM(p_data, 2); /* fixed length */
  UINT16_TO_BE_STREAM(p_data, cmd->player_id);
  p_pkt->len = (p_data - p_start);
  return AVRC_STS_NO_ERROR;
}

/*******************************************************************************
 *
 * Function         avrc_bld_set_addressed_player_cmd
 *
 * Description      This function builds the set addressed player cmd.
 *
 * Returns          AVRC_STS_NO_ERROR, if the command is built successfully
 *                  Otherwise, the error code.
 *
 ******************************************************************************/
static tAVRC_STS avrc_bld_set_addressed_player_cmd(
    BT_HDR* p_pkt, const tAVRC_SET_ADDR_PLAYER_CMD* cmd) {
  AVRC_TRACE_API("%s", __func__);
  /* get the existing length, if any, and also the num attributes */
  uint8_t* p_start = (uint8_t*)(p_pkt + 1) + p_pkt->offset;
  uint8_t* p_data = p_start + 2; /* pdu + rsvd */

  /* To change addressed player the following is the total length:
   * Player ID (2)
   */
  UINT16_TO_BE_STREAM(p_data, 2); /* fixed length */
  UINT16_TO_BE_STREAM(p_data, cmd->player_id);
  p_pkt->len = (p_data - p_start);
  return AVRC_STS_NO_ERROR;
}

/*******************************************************************************
 *
 * Function         avrc_bld_init_cmd_buffer
 *
 * Description      This function initializes the command buffer based on PDU
 *
 * Returns          NULL, if no GKI buffer or failure to build the message.
 *                  Otherwise, the GKI buffer that contains the initialized
 *                  message.
 *
 ******************************************************************************/
static BT_HDR* avrc_bld_init_cmd_buffer(tAVRC_COMMAND* p_cmd) {
  uint16_t chnl = AVCT_DATA_CTRL;
  uint8_t opcode = avrc_opcode_from_pdu(p_cmd->pdu);
  AVRC_TRACE_API("avrc_bld_init_cmd_buffer: pdu=%x, opcode=%x", p_cmd->pdu,
                 opcode);

  uint16_t offset = 0;
  switch (opcode) {
    case AVRC_OP_BROWSE:
      chnl = AVCT_DATA_BROWSE;
      offset = AVCT_BROWSE_OFFSET;
      break;

    case AVRC_OP_PASS_THRU:
      offset = AVRC_MSG_PASS_THRU_OFFSET;
      break;

    case AVRC_OP_VENDOR:
      offset = AVRC_MSG_VENDOR_OFFSET;
      break;
  }

  /* allocate and initialize the buffer */
  BT_HDR* p_pkt = (BT_HDR*)osi_calloc(AVRC_META_CMD_BUF_SIZE);
  uint8_t *p_data, *p_start;

  p_pkt->layer_specific = chnl;
  p_pkt->event = opcode;
  p_pkt->offset = offset;
  p_data = (uint8_t*)(p_pkt + 1) + p_pkt->offset;
  p_start = p_data;

  /* pass thru - group navigation - has a two byte op_id, so dont do it here */
  if (opcode != AVRC_OP_PASS_THRU) *p_data++ = p_cmd->pdu;

  switch (opcode) {
    case AVRC_OP_VENDOR:
      /* reserved 0, packet_type 0 */
      UINT8_TO_BE_STREAM(p_data, 0);
      /* continue to the next "case to add length */
      /* add fixed lenth - 0 */
      UINT16_TO_BE_STREAM(p_data, 0);
      break;
  }

  p_pkt->len = (p_data - p_start);
  p_cmd->cmd.opcode = opcode;

  return p_pkt;
}

/*******************************************************************************
 *
 * Function         AVRC_BldCommand
 *
 * Description      This function builds the given AVRCP command to the given
 *                  GKI buffer
 *
 * Returns          AVRC_STS_NO_ERROR, if the command is built successfully
 *                  Otherwise, the error code.
 *
 ******************************************************************************/
tAVRC_STS AVRC_BldCommand(tAVRC_COMMAND* p_cmd, BT_HDR** pp_pkt) {
  tAVRC_STS status = AVRC_STS_BAD_PARAM;
  bool alloc = false;
  AVRC_TRACE_API("AVRC_BldCommand: pdu=%x status=%x", p_cmd->cmd.pdu,
                 p_cmd->cmd.status);
  if (!p_cmd || !pp_pkt) {
    AVRC_TRACE_API(
        "AVRC_BldCommand. Invalid parameters passed. p_cmd=%p, pp_pkt=%p",
        p_cmd, pp_pkt);
    return AVRC_STS_BAD_PARAM;
  }

  if (*pp_pkt == NULL) {
    *pp_pkt = avrc_bld_init_cmd_buffer(p_cmd);
    if (*pp_pkt == NULL) {
      AVRC_TRACE_API("AVRC_BldCommand: Failed to initialize command buffer");
      return AVRC_STS_INTERNAL_ERR;
    }
    alloc = true;
  }
  status = AVRC_STS_NO_ERROR;
  BT_HDR* p_pkt = *pp_pkt;

  switch (p_cmd->pdu) {
    case AVRC_PDU_REQUEST_CONTINUATION_RSP: /*        0x40 */
      status = avrc_bld_next_cmd(&p_cmd->continu, p_pkt);
      break;

    case AVRC_PDU_ABORT_CONTINUATION_RSP: /*          0x41 */
      status = avrc_bld_next_cmd(&p_cmd->abort, p_pkt);
      break;
#if (AVRC_ADV_CTRL_INCLUDED == TRUE)
    case AVRC_PDU_SET_ABSOLUTE_VOLUME: /* 0x50 */
      status = avrc_bld_set_abs_volume_cmd(&p_cmd->volume, p_pkt);
      break;
#endif
    case AVRC_PDU_REGISTER_NOTIFICATION: /* 0x31 */
#if (AVRC_ADV_CTRL_INCLUDED == TRUE)
      status = avrc_bld_register_notifn(p_pkt, p_cmd->reg_notif.event_id,
                                        p_cmd->reg_notif.param);
#endif
      break;
    case AVRC_PDU_GET_CAPABILITIES:
      status =
          avrc_bld_get_capability_cmd(p_pkt, p_cmd->get_caps.capability_id);
      break;
    case AVRC_PDU_LIST_PLAYER_APP_ATTR:
      status = avrc_bld_list_player_app_attr_cmd(p_pkt);
      break;
    case AVRC_PDU_LIST_PLAYER_APP_VALUES:
      status = avrc_bld_list_player_app_values_cmd(
          p_pkt, p_cmd->list_app_values.attr_id);
      break;
    case AVRC_PDU_GET_CUR_PLAYER_APP_VALUE:
      status = avrc_bld_get_current_player_app_values_cmd(
          p_pkt, p_cmd->get_cur_app_val.num_attr, p_cmd->get_cur_app_val.attrs);
      break;
    case AVRC_PDU_SET_PLAYER_APP_VALUE:
      status = avrc_bld_set_current_player_app_values_cmd(
          p_pkt, p_cmd->set_app_val.num_val, p_cmd->set_app_val.p_vals);
      break;
    case AVRC_PDU_GET_PLAYER_APP_ATTR_TEXT:
      avrc_bld_get_player_app_setting_attr_text_cmd(p_pkt,
                                                    &p_cmd->get_app_attr_txt);
      break;
    case AVRC_PDU_GET_PLAYER_APP_VALUE_TEXT:
      avrc_bld_get_player_app_setting_value_text_cmd(p_pkt,
                                                     &p_cmd->get_app_val_txt);
      break;
    case AVRC_PDU_GET_ELEMENT_ATTR:
      status = avrc_bld_get_element_attr_cmd(
          p_pkt, p_cmd->get_elem_attrs.num_attr, p_cmd->get_elem_attrs.attrs);
      break;
    case AVRC_PDU_PLAY_ITEM:
      status = avrc_bld_play_item_cmd(p_pkt, p_cmd->play_item.scope,
                                      p_cmd->play_item.uid,
                                      p_cmd->play_item.uid_counter);
      break;
    case AVRC_PDU_GET_PLAY_STATUS:
      status = avrc_bld_get_play_status_cmd(p_pkt);
      break;
    case AVRC_PDU_GET_FOLDER_ITEMS:
      status = avrc_bld_get_folder_items_cmd(p_pkt, &(p_cmd->get_items));
      break;
    case AVRC_PDU_CHANGE_PATH:
      status = avrc_bld_change_folder_cmd(p_pkt, &(p_cmd->chg_path));
      break;
    case AVRC_PDU_GET_ITEM_ATTRIBUTES:
      status = avrc_bld_get_item_attributes_cmd(p_pkt, &(p_cmd->get_attrs));
      break;
    case AVRC_PDU_SET_BROWSED_PLAYER:
      status = avrc_bld_set_browsed_player_cmd(p_pkt, &(p_cmd->br_player));
      break;
    case AVRC_PDU_SET_ADDRESSED_PLAYER:
      status = avrc_bld_set_addressed_player_cmd(p_pkt, &(p_cmd->addr_player));
      break;
  }

  if (alloc && (status != AVRC_STS_NO_ERROR)) {
    osi_free(p_pkt);
    *pp_pkt = NULL;
  }
  AVRC_TRACE_API("AVRC_BldCommand: returning %d", status);
  return status;
}