xref: /btstack/example/a2dp_source_demo.c (revision 1d79cae3b74147454aeb193290279af87c1bf6ab)
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__ "a2dp_source_demo.c"
39 
40 /*
41  * a2dp_source_demo.c
42  */
43 
44 // *****************************************************************************
45 /* EXAMPLE_START(a2dp_source_demo): A2DP Source - Stream Audio and Control Volume
46  *
47  * @text This A2DP Source example demonstrates how to send an audio data stream
48  * to a remote A2DP Sink device and how to switch between two audio data sources.
49  * In addition, the AVRCP Target is used to answer queries on currently played media,
50  * as well as to handle remote playback control, i.e. play, stop, repeat, etc. If HAVE_BTSTACK_STDIN
51  * is set, press SPACE on the console to show the available AVDTP and AVRCP commands.
52  *
53  * @text To test with a remote device, e.g. a Bluetooth speaker,
54  * set the device_addr_string to the Bluetooth address of your
55  * remote device in the code, and use the UI to connect and start playback.
56  *
57  * @text For more info on BTstack audio, see our blog post
58  * [A2DP Sink and Source on STM32 F4 Discovery Board](http://bluekitchen-gmbh.com/a2dp-sink-and-source-on-stm32-f4-discovery-board/).
59  *
60  */
61 // *****************************************************************************
62 
63 
64 #include <stdint.h>
65 #include <stdio.h>
66 #include <stdlib.h>
67 #include <string.h>
68 
69 #include "btstack.h"
70 #include "hxcmod.h"
71 #include "mods/mod.h"
72 
73 // logarithmic volume reduction, samples are divided by 2^x
74 // #define VOLUME_REDUCTION 3
75 // #undef  HAVE_BTSTACK_STDIN
76 
77 //#define AVRCP_BROWSING_ENABLED
78 
79 #define NUM_CHANNELS                2
80 #define BYTES_PER_AUDIO_SAMPLE      (2*NUM_CHANNELS)
81 #define AUDIO_TIMEOUT_MS            10
82 #define TABLE_SIZE_441HZ            100
83 
84 #define SBC_STORAGE_SIZE 1030
85 
86 typedef enum {
87     STREAM_SINE = 0,
88     STREAM_MOD,
89     STREAM_PTS_TEST
90 } stream_data_source_t;
91 
92 typedef struct {
93     uint16_t a2dp_cid;
94     uint8_t  local_seid;
95     uint8_t  remote_seid;
96     uint8_t  stream_opened;
97     uint16_t avrcp_cid;
98 
99     uint32_t time_audio_data_sent; // ms
100     uint32_t acc_num_missed_samples;
101     uint32_t samples_ready;
102     btstack_timer_source_t audio_timer;
103     uint8_t  streaming;
104     int      max_media_payload_size;
105 
106     uint8_t  sbc_storage[SBC_STORAGE_SIZE];
107     uint16_t sbc_storage_count;
108     uint8_t  sbc_ready_to_send;
109 
110     uint16_t volume;
111 } a2dp_media_sending_context_t;
112 
113 static  uint8_t media_sbc_codec_capabilities[] = {
114     (AVDTP_SBC_44100 << 4) | AVDTP_SBC_STEREO,
115     0xFF,//(AVDTP_SBC_BLOCK_LENGTH_16 << 4) | (AVDTP_SBC_SUBBANDS_8 << 2) | AVDTP_SBC_ALLOCATION_METHOD_LOUDNESS,
116     2, 53
117 };
118 
119 // input signal: pre-computed int16 sine wave, 44100 Hz at 441 Hz
120 static const int16_t sine_int16_44100[] = {
121      0,    2057,    4107,    6140,    8149,   10126,   12062,   13952,   15786,   17557,
122  19260,   20886,   22431,   23886,   25247,   26509,   27666,   28714,   29648,   30466,
123  31163,   31738,   32187,   32509,   32702,   32767,   32702,   32509,   32187,   31738,
124  31163,   30466,   29648,   28714,   27666,   26509,   25247,   23886,   22431,   20886,
125  19260,   17557,   15786,   13952,   12062,   10126,    8149,    6140,    4107,    2057,
126      0,   -2057,   -4107,   -6140,   -8149,  -10126,  -12062,  -13952,  -15786,  -17557,
127 -19260,  -20886,  -22431,  -23886,  -25247,  -26509,  -27666,  -28714,  -29648,  -30466,
128 -31163,  -31738,  -32187,  -32509,  -32702,  -32767,  -32702,  -32509,  -32187,  -31738,
129 -31163,  -30466,  -29648,  -28714,  -27666,  -26509,  -25247,  -23886,  -22431,  -20886,
130 -19260,  -17557,  -15786,  -13952,  -12062,  -10126,   -8149,   -6140,   -4107,   -2057,
131 };
132 
133 static const int num_samples_sine_int16_44100 = sizeof(sine_int16_44100) / 2;
134 
135 // input signal: pre-computed int16 sine wave, 48000 Hz at 441 Hz
136 static const int16_t sine_int16_48000[] = {
137      0,    1905,    3804,    5690,    7557,    9398,   11207,   12978,   14706,   16383,
138  18006,   19567,   21062,   22486,   23834,   25101,   26283,   27376,   28377,   29282,
139  30087,   30791,   31390,   31884,   32269,   32545,   32712,   32767,   32712,   32545,
140  32269,   31884,   31390,   30791,   30087,   29282,   28377,   27376,   26283,   25101,
141  23834,   22486,   21062,   19567,   18006,   16383,   14706,   12978,   11207,    9398,
142   7557,    5690,    3804,    1905,       0,   -1905,   -3804,   -5690,   -7557,   -9398,
143 -11207,  -12978,  -14706,  -16384,  -18006,  -19567,  -21062,  -22486,  -23834,  -25101,
144 -26283,  -27376,  -28377,  -29282,  -30087,  -30791,  -31390,  -31884,  -32269,  -32545,
145 -32712,  -32767,  -32712,  -32545,  -32269,  -31884,  -31390,  -30791,  -30087,  -29282,
146 -28377,  -27376,  -26283,  -25101,  -23834,  -22486,  -21062,  -19567,  -18006,  -16384,
147 -14706,  -12978,  -11207,   -9398,   -7557,   -5690,   -3804,   -1905,  };
148 
149 static const int num_samples_sine_int16_48000 = sizeof(sine_int16_48000) / 2;
150 
151 typedef struct {
152     int reconfigure;
153 
154     int num_channels;
155     int sampling_frequency;
156     int block_length;
157     int subbands;
158     int min_bitpool_value;
159     int max_bitpool_value;
160     btstack_sbc_channel_mode_t      channel_mode;
161     btstack_sbc_allocation_method_t allocation_method;
162 } media_codec_configuration_sbc_t;
163 
164 static btstack_packet_callback_registration_t hci_event_callback_registration;
165 
166 // pts:             static const char * device_addr_string = "00:1B:DC:08:0A:A5";
167 // pts:             static const char * device_addr_string = "00:1B:DC:08:E2:72";
168 // mac 2013:        static const char * device_addr_string = "84:38:35:65:d1:15";
169 // phone 2013:      static const char * device_addr_string = "D8:BB:2C:DF:F0:F2";
170 // Minijambox:
171 static const char * device_addr_string = "00:21:3C:AC:F7:38";
172 // Philips SHB9100: static const char * device_addr_string = "00:22:37:05:FD:E8";
173 // RT-B6:           static const char * device_addr_string = "00:75:58:FF:C9:7D";
174 // BT dongle:       static const char * device_addr_string = "00:1A:7D:DA:71:0A";
175 // Sony MDR-ZX330BT static const char * device_addr_string = "00:18:09:28:50:18";
176 // Panda (BM6)      static const char * device_addr_string = "4F:3F:66:52:8B:E0";
177 // BeatsX:          static const char * device_addr_string = "DC:D3:A2:89:57:FB";
178 // Green mushroom:  static const char * device_addr_string = "41:42:2A:ED:D6:F3";
179 
180 static bd_addr_t device_addr;
181 
182 static uint8_t sdp_a2dp_source_service_buffer[150];
183 static uint8_t sdp_avrcp_target_service_buffer[200];
184 static uint8_t sdp_avrcp_controller_service_buffer[200];
185 static uint8_t device_id_sdp_service_buffer[100];
186 
187 static media_codec_configuration_sbc_t sbc_configuration;
188 static btstack_sbc_encoder_state_t sbc_encoder_state;
189 
190 static uint8_t media_sbc_codec_configuration[4];
191 static a2dp_media_sending_context_t media_tracker;
192 
193 static stream_data_source_t data_source;
194 
195 static int sine_phase;
196 static int current_sample_rate = 44100;
197 static int new_sample_rate = 44100;
198 
199 static int hxcmod_initialized;
200 static modcontext mod_context;
201 static tracker_buffer_state trkbuf;
202 
203 /* AVRCP Target context START */
204 static const uint8_t subunit_info[] = {
205     0,0,0,0,
206     1,1,1,1,
207     2,2,2,2,
208     3,3,3,3,
209     4,4,4,4,
210     5,5,5,5,
211     6,6,6,6,
212     7,7,7,7
213 };
214 
215 static uint32_t company_id = 0x112233;
216 static uint8_t  companies_num = 1;
217 static uint8_t  companies[] = {
218     0x00, 0x19, 0x58 //BT SIG registered CompanyID
219 };
220 
221 static uint8_t events_num = 6;
222 static uint8_t events[] = {
223     AVRCP_NOTIFICATION_EVENT_PLAYBACK_STATUS_CHANGED,
224     AVRCP_NOTIFICATION_EVENT_TRACK_CHANGED,
225     AVRCP_NOTIFICATION_EVENT_PLAYER_APPLICATION_SETTING_CHANGED,
226     AVRCP_NOTIFICATION_EVENT_NOW_PLAYING_CONTENT_CHANGED,
227     AVRCP_NOTIFICATION_EVENT_AVAILABLE_PLAYERS_CHANGED,
228     AVRCP_NOTIFICATION_EVENT_ADDRESSED_PLAYER_CHANGED
229 };
230 
231 typedef struct {
232     uint8_t track_id[8];
233     uint32_t song_length_ms;
234     avrcp_playback_status_t status;
235     uint32_t song_position_ms; // 0xFFFFFFFF if not supported
236 } avrcp_play_status_info_t;
237 
238 // python -c "print('a'*512)"
239 static const char title[] = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
240 
241 avrcp_track_t tracks[] = {
242     {{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01}, 1, "Sine", "Generated", "A2DP Source Demo", "monotone", 12345},
243     {{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02}, 2, "Nao-deceased", "Decease", "A2DP Source Demo", "vivid", 12345},
244     {{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03}, 3, (char *)title, "Decease", "A2DP Source Demo", "vivid", 12345},
245 };
246 int current_track_index;
247 avrcp_play_status_info_t play_info;
248 
249 /* AVRCP Target context END */
250 
251 /* @section Main Application Setup
252  *
253  * @text The Listing MainConfiguration shows how to setup AD2P Source and AVRCP services.
254  * Besides calling init() method for each service, you'll also need to register several packet handlers:
255  * - hci_packet_handler - handles legacy pairing, here by using fixed '0000' pin code.
256  * - a2dp_source_packet_handler - handles events on stream connection status (established, released), the media codec configuration, and, the commands on stream itself (open, pause, stopp).
257  * - avrcp_packet_handler - receives connect/disconnect event.
258  * - avrcp_controller_packet_handler - receives answers for sent AVRCP commands.
259  * - avrcp_target_packet_handler - receives AVRCP commands, and registered notifications.
260  * - stdin_process - used to trigger AVRCP commands to the A2DP Source device, such are get now playing info, start, stop, volume control. Requires HAVE_BTSTACK_STDIN.
261  *
262  * @text To announce A2DP Source and AVRCP services, you need to create corresponding
263  * SDP records and register them with the SDP service.
264  */
265 
266 /* LISTING_START(MainConfiguration): Setup Audio Source and AVRCP Target services */
267 static void hci_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
268 static void a2dp_source_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t * event, uint16_t event_size);
269 static void avrcp_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
270 static void avrcp_target_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
271 static void avrcp_controller_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
272 #ifdef HAVE_BTSTACK_STDIN
273 static void stdin_process(char cmd);
274 #endif
275 
276 static void a2dp_demo_hexcmod_configure_sample_rate(int sample_rate);
277 
278 static int a2dp_source_and_avrcp_services_init(void){
279     // Request role change on reconnecting headset to always use them in slave mode
280     hci_set_master_slave_policy(0);
281 
282     l2cap_init();
283     // Initialize  A2DP Source
284     a2dp_source_init();
285     a2dp_source_register_packet_handler(&a2dp_source_packet_handler);
286 
287     // Create stream endpoint
288     avdtp_stream_endpoint_t * local_stream_endpoint = a2dp_source_create_stream_endpoint(AVDTP_AUDIO, AVDTP_CODEC_SBC, media_sbc_codec_capabilities, sizeof(media_sbc_codec_capabilities), media_sbc_codec_configuration, sizeof(media_sbc_codec_configuration));
289     if (!local_stream_endpoint){
290         printf("A2DP Source: not enough memory to create local stream endpoint\n");
291         return 1;
292     }
293 
294     // Store stream enpoint's SEP ID, as it is used by A2DP API to indentify the stream endpoint
295     media_tracker.local_seid = avdtp_local_seid(local_stream_endpoint);
296     avdtp_source_register_delay_reporting_category(media_tracker.local_seid);
297 
298     // Initialize AVRCP Service
299     avrcp_init();
300     avrcp_register_packet_handler(&avrcp_packet_handler);
301     // Initialize AVRCP Target
302     avrcp_target_init();
303     avrcp_target_register_packet_handler(&avrcp_target_packet_handler);
304     // Initialize AVRCP Controller
305     avrcp_controller_init();
306     avrcp_controller_register_packet_handler(&avrcp_controller_packet_handler);
307 
308     // Initialize SDP,
309     sdp_init();
310 
311     // Create A2DP Source service record and register it with SDP
312     memset(sdp_a2dp_source_service_buffer, 0, sizeof(sdp_a2dp_source_service_buffer));
313     a2dp_source_create_sdp_record(sdp_a2dp_source_service_buffer, 0x10001, AVDTP_SOURCE_FEATURE_MASK_PLAYER, NULL, NULL);
314     sdp_register_service(sdp_a2dp_source_service_buffer);
315 
316     // Create AVRCP target service record and register it with SDP
317     memset(sdp_avrcp_target_service_buffer, 0, sizeof(sdp_avrcp_target_service_buffer));
318     uint16_t supported_features = AVRCP_FEATURE_MASK_CATEGORY_PLAYER_OR_RECORDER;
319 #ifdef AVRCP_BROWSING_ENABLED
320     supported_features |= AVRCP_FEATURE_MASK_BROWSING;
321 #endif
322     avrcp_target_create_sdp_record(sdp_avrcp_target_service_buffer, 0x10002, supported_features, NULL, NULL);
323     sdp_register_service(sdp_avrcp_target_service_buffer);
324 
325     // Register AVRCP Controller
326     memset(sdp_avrcp_controller_service_buffer, 0, sizeof(sdp_avrcp_controller_service_buffer));
327     uint16_t controller_supported_features = AVRCP_FEATURE_MASK_CATEGORY_PLAYER_OR_RECORDER;
328     avrcp_controller_create_sdp_record(sdp_avrcp_controller_service_buffer, 0x10003, controller_supported_features, NULL, NULL);
329     sdp_register_service(sdp_avrcp_controller_service_buffer);
330 
331     // Register Device ID (PnP) service SDP record
332     memset(device_id_sdp_service_buffer, 0, sizeof(device_id_sdp_service_buffer));
333     device_id_create_sdp_record(device_id_sdp_service_buffer, 0x10004, DEVICE_ID_VENDOR_ID_SOURCE_BLUETOOTH, BLUETOOTH_COMPANY_ID_BLUEKITCHEN_GMBH, 1, 1);
334     sdp_register_service(device_id_sdp_service_buffer);
335 
336     // Set local name with a template Bluetooth address, that will be automatically
337     // replaced with a actual address once it is available, i.e. when BTstack boots
338     // up and starts talking to a Bluetooth module.
339     gap_set_local_name("A2DP Source 00:00:00:00:00:00");
340     gap_discoverable_control(1);
341     gap_set_class_of_device(0x200408);
342 
343     // Register for HCI events.
344     hci_event_callback_registration.callback = &hci_packet_handler;
345     hci_add_event_handler(&hci_event_callback_registration);
346 
347     a2dp_demo_hexcmod_configure_sample_rate(current_sample_rate);
348 
349 #ifdef HAVE_BTSTACK_STDIN
350     // Parse human readable Bluetooth address.
351     sscanf_bd_addr(device_addr_string, device_addr);
352     btstack_stdin_setup(stdin_process);
353 #endif
354     return 0;
355 }
356 /* LISTING_END */
357 
358 static void a2dp_demo_hexcmod_configure_sample_rate(int sample_rate){
359     if (!hxcmod_initialized){
360         hxcmod_initialized = hxcmod_init(&mod_context);
361         if (!hxcmod_initialized) {
362             printf("could not initialize hxcmod\n");
363             return;
364         }
365     }
366     current_sample_rate = sample_rate;
367     media_tracker.sbc_storage_count = 0;
368     media_tracker.samples_ready = 0;
369     hxcmod_unload(&mod_context);
370     hxcmod_setcfg(&mod_context, current_sample_rate, 16, 1, 1, 1);
371     hxcmod_load(&mod_context, (void *) &mod_data, mod_len);
372 }
373 
374 static void a2dp_demo_send_media_packet(void){
375     int num_bytes_in_frame = btstack_sbc_encoder_sbc_buffer_length();
376     int bytes_in_storage = media_tracker.sbc_storage_count;
377     uint8_t num_frames = bytes_in_storage / num_bytes_in_frame;
378     // Prepend SBC Header
379     media_tracker.sbc_storage[0] = num_frames;  // (fragmentation << 7) | (starting_packet << 6) | (last_packet << 5) | num_frames;
380     avdtp_source_stream_send_media_payload_rtp(media_tracker.a2dp_cid, media_tracker.local_seid, 0, media_tracker.sbc_storage, bytes_in_storage + 1);
381 
382     media_tracker.sbc_storage_count = 0;
383     media_tracker.sbc_ready_to_send = 0;
384 }
385 
386 static void produce_sine_audio(int16_t * pcm_buffer, int num_samples_to_write){
387     int count;
388     for (count = 0; count < num_samples_to_write ; count++){
389         switch (current_sample_rate){
390             case 44100:
391                 pcm_buffer[count * 2]     = sine_int16_44100[sine_phase];
392                 pcm_buffer[count * 2 + 1] = sine_int16_44100[sine_phase];
393                 sine_phase++;
394                 if (sine_phase >= num_samples_sine_int16_44100){
395                     sine_phase -= num_samples_sine_int16_44100;
396                 }
397                 break;
398             case 48000:
399                 pcm_buffer[count * 2]     = sine_int16_48000[sine_phase];
400                 pcm_buffer[count * 2 + 1] = sine_int16_48000[sine_phase];
401                 sine_phase++;
402                 if (sine_phase >= num_samples_sine_int16_48000){
403                     sine_phase -= num_samples_sine_int16_48000;
404                 }
405                 break;
406             default:
407                 break;
408         }
409     }
410 }
411 
412 static void produce_mod_audio(int16_t * pcm_buffer, int num_samples_to_write){
413     hxcmod_fillbuffer(&mod_context, (unsigned short *) &pcm_buffer[0], num_samples_to_write, &trkbuf);
414 }
415 
416 static void produce_audio(int16_t * pcm_buffer, int num_samples){
417     switch (data_source){
418         case STREAM_SINE:
419             produce_sine_audio(pcm_buffer, num_samples);
420             break;
421         case STREAM_MOD:
422             produce_mod_audio(pcm_buffer, num_samples);
423             break;
424         default:
425             break;
426     }
427 #ifdef VOLUME_REDUCTION
428     int i;
429     for (i=0;i<num_samples*2;i++){
430         if (pcm_buffer[i] > 0){
431             pcm_buffer[i] =     pcm_buffer[i]  >> VOLUME_REDUCTION;
432         } else {
433             pcm_buffer[i] = -((-pcm_buffer[i]) >> VOLUME_REDUCTION);
434         }
435     }
436 #endif
437 }
438 
439 static int a2dp_demo_fill_sbc_audio_buffer(a2dp_media_sending_context_t * context){
440     // perform sbc encoding
441     int total_num_bytes_read = 0;
442     unsigned int num_audio_samples_per_sbc_buffer = btstack_sbc_encoder_num_audio_frames();
443     while (context->samples_ready >= num_audio_samples_per_sbc_buffer
444         && (context->max_media_payload_size - context->sbc_storage_count) >= btstack_sbc_encoder_sbc_buffer_length()){
445 
446         int16_t pcm_frame[256*NUM_CHANNELS];
447 
448         produce_audio(pcm_frame, num_audio_samples_per_sbc_buffer);
449         btstack_sbc_encoder_process_data(pcm_frame);
450 
451         uint16_t sbc_frame_size = btstack_sbc_encoder_sbc_buffer_length();
452         uint8_t * sbc_frame = btstack_sbc_encoder_sbc_buffer();
453 
454         total_num_bytes_read += num_audio_samples_per_sbc_buffer;
455         // first byte in sbc storage contains sbc media header
456         memcpy(&context->sbc_storage[1 + context->sbc_storage_count], sbc_frame, sbc_frame_size);
457         context->sbc_storage_count += sbc_frame_size;
458         context->samples_ready -= num_audio_samples_per_sbc_buffer;
459     }
460     return total_num_bytes_read;
461 }
462 
463 static void a2dp_demo_audio_timeout_handler(btstack_timer_source_t * timer){
464     a2dp_media_sending_context_t * context = (a2dp_media_sending_context_t *) btstack_run_loop_get_timer_context(timer);
465     btstack_run_loop_set_timer(&context->audio_timer, AUDIO_TIMEOUT_MS);
466     btstack_run_loop_add_timer(&context->audio_timer);
467     uint32_t now = btstack_run_loop_get_time_ms();
468 
469     uint32_t update_period_ms = AUDIO_TIMEOUT_MS;
470     if (context->time_audio_data_sent > 0){
471         update_period_ms = now - context->time_audio_data_sent;
472     }
473 
474     uint32_t num_samples = (update_period_ms * current_sample_rate) / 1000;
475     context->acc_num_missed_samples += (update_period_ms * current_sample_rate) % 1000;
476 
477     while (context->acc_num_missed_samples >= 1000){
478         num_samples++;
479         context->acc_num_missed_samples -= 1000;
480     }
481     context->time_audio_data_sent = now;
482     context->samples_ready += num_samples;
483 
484     if (context->sbc_ready_to_send) return;
485 
486     a2dp_demo_fill_sbc_audio_buffer(context);
487 
488     if ((context->sbc_storage_count + btstack_sbc_encoder_sbc_buffer_length()) > context->max_media_payload_size){
489         // schedule sending
490         context->sbc_ready_to_send = 1;
491         a2dp_source_stream_endpoint_request_can_send_now(context->a2dp_cid, context->local_seid);
492     }
493 }
494 
495 static void a2dp_demo_timer_start(a2dp_media_sending_context_t * context){
496     context->max_media_payload_size = btstack_min(a2dp_max_media_payload_size(context->a2dp_cid, context->local_seid), SBC_STORAGE_SIZE);
497     context->sbc_storage_count = 0;
498     context->sbc_ready_to_send = 0;
499     context->streaming = 1;
500     btstack_run_loop_remove_timer(&context->audio_timer);
501     btstack_run_loop_set_timer_handler(&context->audio_timer, a2dp_demo_audio_timeout_handler);
502     btstack_run_loop_set_timer_context(&context->audio_timer, context);
503     btstack_run_loop_set_timer(&context->audio_timer, AUDIO_TIMEOUT_MS);
504     btstack_run_loop_add_timer(&context->audio_timer);
505 }
506 
507 static void a2dp_demo_timer_stop(a2dp_media_sending_context_t * context){
508     context->time_audio_data_sent = 0;
509     context->acc_num_missed_samples = 0;
510     context->samples_ready = 0;
511     context->streaming = 1;
512     context->sbc_storage_count = 0;
513     context->sbc_ready_to_send = 0;
514     btstack_run_loop_remove_timer(&context->audio_timer);
515 }
516 
517 static void dump_sbc_configuration(media_codec_configuration_sbc_t * configuration){
518     printf("Received media codec configuration:\n");
519     printf("    - num_channels: %d\n", configuration->num_channels);
520     printf("    - sampling_frequency: %d\n", configuration->sampling_frequency);
521     printf("    - channel_mode: %d\n", configuration->channel_mode);
522     printf("    - block_length: %d\n", configuration->block_length);
523     printf("    - subbands: %d\n", configuration->subbands);
524     printf("    - allocation_method: %d\n", configuration->allocation_method);
525     printf("    - bitpool_value [%d, %d] \n", configuration->min_bitpool_value, configuration->max_bitpool_value);
526 }
527 
528 static void hci_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
529     UNUSED(channel);
530     UNUSED(size);
531     if (packet_type != HCI_EVENT_PACKET) return;
532 
533 #ifndef HAVE_BTSTACK_STDIN
534     if (hci_event_packet_get_type(packet) == BTSTACK_EVENT_STATE){
535         if (btstack_event_state_get_state(packet) != HCI_STATE_WORKING) return;
536         printf("Create A2DP Source connection to addr %s.\n", bd_addr_to_str(device_addr));
537         uint8_t status = a2dp_source_establish_stream(device_addr, media_tracker.local_seid, &media_tracker.a2dp_cid);
538         if (status != ERROR_CODE_SUCCESS){
539             printf("Could not perform command, status 0x%2x\n", status);
540         }
541         return;
542     }
543 #endif
544 
545     if (hci_event_packet_get_type(packet) == HCI_EVENT_PIN_CODE_REQUEST) {
546         bd_addr_t address;
547         printf("Pin code request - using '0000'\n");
548         hci_event_pin_code_request_get_bd_addr(packet, address);
549         gap_pin_code_response(address, "0000");
550     }
551 }
552 
553 static void a2dp_source_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
554     UNUSED(channel);
555     UNUSED(size);
556     uint8_t status;
557     uint8_t local_seid;
558     bd_addr_t address;
559     uint16_t cid;
560 
561     uint8_t channel_mode;
562     uint8_t allocation_method;
563 
564     if (packet_type != HCI_EVENT_PACKET) return;
565     if (hci_event_packet_get_type(packet) != HCI_EVENT_A2DP_META) return;
566 
567     switch (hci_event_a2dp_meta_get_subevent_code(packet)){
568         case A2DP_SUBEVENT_SIGNALING_CONNECTION_ESTABLISHED:
569             a2dp_subevent_signaling_connection_established_get_bd_addr(packet, address);
570             cid = a2dp_subevent_signaling_connection_established_get_a2dp_cid(packet);
571             status = a2dp_subevent_signaling_connection_established_get_status(packet);
572 
573             if (status != ERROR_CODE_SUCCESS){
574                 printf("A2DP Source: Connection failed, status 0x%02x, cid 0x%02x, a2dp_cid 0x%02x \n", status, cid, media_tracker.a2dp_cid);
575                 media_tracker.a2dp_cid = 0;
576                 break;
577             }
578             media_tracker.a2dp_cid = cid;
579             media_tracker.volume = 32;
580 
581             printf("A2DP Source: Connected to address %s, a2dp cid 0x%02x, local seid 0x%02x.\n", bd_addr_to_str(address), media_tracker.a2dp_cid, media_tracker.local_seid);
582             break;
583 
584          case A2DP_SUBEVENT_SIGNALING_MEDIA_CODEC_SBC_CONFIGURATION:{
585             cid  = avdtp_subevent_signaling_media_codec_sbc_configuration_get_avdtp_cid(packet);
586             if (cid != media_tracker.a2dp_cid) return;
587 
588             media_tracker.remote_seid = a2dp_subevent_signaling_media_codec_sbc_configuration_get_remote_seid(packet);
589 
590             sbc_configuration.reconfigure = a2dp_subevent_signaling_media_codec_sbc_configuration_get_reconfigure(packet);
591             sbc_configuration.num_channels = a2dp_subevent_signaling_media_codec_sbc_configuration_get_num_channels(packet);
592             sbc_configuration.sampling_frequency = a2dp_subevent_signaling_media_codec_sbc_configuration_get_sampling_frequency(packet);
593             sbc_configuration.block_length = a2dp_subevent_signaling_media_codec_sbc_configuration_get_block_length(packet);
594             sbc_configuration.subbands = a2dp_subevent_signaling_media_codec_sbc_configuration_get_subbands(packet);
595             sbc_configuration.min_bitpool_value = a2dp_subevent_signaling_media_codec_sbc_configuration_get_min_bitpool_value(packet);
596             sbc_configuration.max_bitpool_value = a2dp_subevent_signaling_media_codec_sbc_configuration_get_max_bitpool_value(packet);
597 
598             channel_mode = a2dp_subevent_signaling_media_codec_sbc_configuration_get_channel_mode(packet);
599             allocation_method = a2dp_subevent_signaling_media_codec_sbc_configuration_get_allocation_method(packet);
600 
601             printf("A2DP Source: Received SBC codec configuration, sampling frequency %u, a2dp_cid 0x%02x, local seid 0x%02x, remote seid 0x%02x.\n",
602                 sbc_configuration.sampling_frequency, cid,
603                    a2dp_subevent_signaling_media_codec_sbc_configuration_get_local_seid(packet),
604                    a2dp_subevent_signaling_media_codec_sbc_configuration_get_remote_seid(packet));
605 
606             // Adapt Bluetooth spec definition to SBC Encoder expected input
607             sbc_configuration.allocation_method = (btstack_sbc_allocation_method_t)(allocation_method - 1);
608             sbc_configuration.num_channels = SBC_CHANNEL_MODE_STEREO;
609             switch (channel_mode){
610                 case AVDTP_SBC_JOINT_STEREO:
611                     sbc_configuration.channel_mode = SBC_CHANNEL_MODE_JOINT_STEREO;
612                     break;
613                 case AVDTP_SBC_STEREO:
614                     sbc_configuration.channel_mode = SBC_CHANNEL_MODE_STEREO;
615                     break;
616                 case AVDTP_SBC_DUAL_CHANNEL:
617                     sbc_configuration.channel_mode = SBC_CHANNEL_MODE_DUAL_CHANNEL;
618                     break;
619                 case AVDTP_SBC_MONO:
620                     sbc_configuration.channel_mode = SBC_CHANNEL_MODE_MONO;
621                     sbc_configuration.num_channels = 1;
622                     break;
623                 default:
624                     btstack_assert(false);
625                     break;
626             }
627             dump_sbc_configuration(&sbc_configuration);
628 
629             btstack_sbc_encoder_init(&sbc_encoder_state, SBC_MODE_STANDARD,
630                 sbc_configuration.block_length, sbc_configuration.subbands,
631                 sbc_configuration.allocation_method, sbc_configuration.sampling_frequency,
632                 sbc_configuration.max_bitpool_value,
633                 sbc_configuration.channel_mode);
634             break;
635         }
636 
637         case A2DP_SUBEVENT_SIGNALING_DELAY_REPORTING_CAPABILITY:
638             printf("A2DP Source: remote supports delay report, remote seid %d\n",
639                 avdtp_subevent_signaling_delay_reporting_capability_get_remote_seid(packet));
640             break;
641         case A2DP_SUBEVENT_SIGNALING_CAPABILITIES_DONE:
642             printf("A2DP Source: All capabilities reported, remote seid %d\n",
643                 avdtp_subevent_signaling_capabilities_done_get_remote_seid(packet));
644             break;
645 
646         case A2DP_SUBEVENT_SIGNALING_DELAY_REPORT:
647             printf("A2DP Source: Received delay report of %d.%0d ms, local seid %d\n",
648                 avdtp_subevent_signaling_delay_report_get_delay_100us(packet)/10, avdtp_subevent_signaling_delay_report_get_delay_100us(packet)%10,
649                 avdtp_subevent_signaling_delay_report_get_local_seid(packet));
650             break;
651 
652         case A2DP_SUBEVENT_STREAM_ESTABLISHED:
653             a2dp_subevent_stream_established_get_bd_addr(packet, address);
654             status = a2dp_subevent_stream_established_get_status(packet);
655             if (status){
656                 printf("A2DP Source: Stream failed, status 0x%02x.\n", status);
657                 break;
658             }
659 
660             local_seid = a2dp_subevent_stream_established_get_local_seid(packet);
661             cid = a2dp_subevent_stream_established_get_a2dp_cid(packet);
662 
663             printf("A2DP Source: Stream established a2dp_cid 0x%02x, local_seid 0x%02x, remote_seid 0x%02x\n", cid, local_seid, a2dp_subevent_stream_established_get_remote_seid(packet));
664 
665             a2dp_demo_hexcmod_configure_sample_rate(current_sample_rate);
666             media_tracker.stream_opened = 1;
667             data_source = STREAM_MOD;
668             status = a2dp_source_start_stream(media_tracker.a2dp_cid, media_tracker.local_seid);
669             break;
670 
671         case A2DP_SUBEVENT_STREAM_RECONFIGURED:
672             status = a2dp_subevent_stream_reconfigured_get_status(packet);
673             local_seid = a2dp_subevent_stream_reconfigured_get_local_seid(packet);
674             cid = a2dp_subevent_stream_reconfigured_get_a2dp_cid(packet);
675 
676             if (status != ERROR_CODE_SUCCESS){
677                 printf("A2DP Source: Stream reconfiguration failed with status 0x%02x\n", status);
678                 break;
679             }
680 
681             printf("A2DP Source: Stream reconfigured a2dp_cid 0x%02x, local_seid 0x%02x\n", cid, local_seid);
682             a2dp_demo_hexcmod_configure_sample_rate(new_sample_rate);
683             status = a2dp_source_start_stream(media_tracker.a2dp_cid, media_tracker.local_seid);
684             break;
685 
686         case A2DP_SUBEVENT_STREAM_STARTED:
687             local_seid = a2dp_subevent_stream_started_get_local_seid(packet);
688             cid = a2dp_subevent_stream_started_get_a2dp_cid(packet);
689 
690             play_info.status = AVRCP_PLAYBACK_STATUS_PLAYING;
691             if (media_tracker.avrcp_cid){
692                 avrcp_target_set_now_playing_info(media_tracker.avrcp_cid, &tracks[data_source], sizeof(tracks)/sizeof(avrcp_track_t));
693                 avrcp_target_set_playback_status(media_tracker.avrcp_cid, AVRCP_PLAYBACK_STATUS_PLAYING);
694             }
695             a2dp_demo_timer_start(&media_tracker);
696             printf("A2DP Source: Stream started, a2dp_cid 0x%02x, local_seid 0x%02x\n", cid, local_seid);
697             break;
698 
699         case A2DP_SUBEVENT_STREAMING_CAN_SEND_MEDIA_PACKET_NOW:
700             local_seid = a2dp_subevent_streaming_can_send_media_packet_now_get_local_seid(packet);
701             cid = a2dp_subevent_signaling_media_codec_sbc_configuration_get_a2dp_cid(packet);
702             a2dp_demo_send_media_packet();
703             break;
704 
705         case A2DP_SUBEVENT_STREAM_SUSPENDED:
706             local_seid = a2dp_subevent_stream_suspended_get_local_seid(packet);
707             cid = a2dp_subevent_stream_suspended_get_a2dp_cid(packet);
708 
709             play_info.status = AVRCP_PLAYBACK_STATUS_PAUSED;
710             if (media_tracker.avrcp_cid){
711                 avrcp_target_set_playback_status(media_tracker.avrcp_cid, AVRCP_PLAYBACK_STATUS_PAUSED);
712             }
713             printf("A2DP Source: Stream paused, a2dp_cid 0x%02x, local_seid 0x%02x\n", cid, local_seid);
714 
715             a2dp_demo_timer_stop(&media_tracker);
716             break;
717 
718         case A2DP_SUBEVENT_STREAM_RELEASED:
719             play_info.status = AVRCP_PLAYBACK_STATUS_STOPPED;
720             cid = a2dp_subevent_stream_released_get_a2dp_cid(packet);
721             local_seid = a2dp_subevent_stream_released_get_local_seid(packet);
722 
723             printf("A2DP Source: Stream released, a2dp_cid 0x%02x, local_seid 0x%02x\n", cid, local_seid);
724 
725             if (cid == media_tracker.a2dp_cid) {
726                 media_tracker.stream_opened = 0;
727                 printf("A2DP Source: Stream released.\n");
728             }
729             if (media_tracker.avrcp_cid){
730                 avrcp_target_set_now_playing_info(media_tracker.avrcp_cid, NULL, sizeof(tracks)/sizeof(avrcp_track_t));
731                 avrcp_target_set_playback_status(media_tracker.avrcp_cid, AVRCP_PLAYBACK_STATUS_STOPPED);
732             }
733             a2dp_demo_timer_stop(&media_tracker);
734             break;
735         case A2DP_SUBEVENT_SIGNALING_CONNECTION_RELEASED:
736             cid = a2dp_subevent_signaling_connection_released_get_a2dp_cid(packet);
737             if (cid == media_tracker.a2dp_cid) {
738                 media_tracker.avrcp_cid = 0;
739                 media_tracker.a2dp_cid = 0;
740                 printf("A2DP Source: Signaling released.\n\n");
741             }
742             break;
743         default:
744             break;
745     }
746 }
747 
748 static void avrcp_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
749     UNUSED(channel);
750     UNUSED(size);
751     bd_addr_t event_addr;
752     uint16_t local_cid;
753     uint8_t  status = ERROR_CODE_SUCCESS;
754 
755     if (packet_type != HCI_EVENT_PACKET) return;
756     if (hci_event_packet_get_type(packet) != HCI_EVENT_AVRCP_META) return;
757 
758     switch (packet[2]){
759         case AVRCP_SUBEVENT_CONNECTION_ESTABLISHED:
760             local_cid = avrcp_subevent_connection_established_get_avrcp_cid(packet);
761             status = avrcp_subevent_connection_established_get_status(packet);
762             if (status != ERROR_CODE_SUCCESS){
763                 printf("AVRCP: Connection failed, local cid 0x%02x, status 0x%02x\n", local_cid, status);
764                 return;
765             }
766             media_tracker.avrcp_cid = local_cid;
767             avrcp_subevent_connection_established_get_bd_addr(packet, event_addr);
768 
769             avrcp_target_set_now_playing_info(media_tracker.avrcp_cid, NULL, sizeof(tracks)/sizeof(avrcp_track_t));
770             avrcp_target_set_unit_info(media_tracker.avrcp_cid, AVRCP_SUBUNIT_TYPE_AUDIO, company_id);
771             avrcp_target_set_subunit_info(media_tracker.avrcp_cid, AVRCP_SUBUNIT_TYPE_AUDIO, (uint8_t *)subunit_info, sizeof(subunit_info));
772 
773             avrcp_controller_get_supported_events(media_tracker.avrcp_cid);
774 
775             printf("AVRCP: Channel successfully opened:  media_tracker.avrcp_cid 0x%02x\n", media_tracker.avrcp_cid);
776             return;
777 
778         case AVRCP_SUBEVENT_CONNECTION_RELEASED:
779             printf("AVRCP Target: Disconnected, avrcp_cid 0x%02x\n", avrcp_subevent_connection_released_get_avrcp_cid(packet));
780             media_tracker.avrcp_cid = 0;
781             return;
782         default:
783             break;
784     }
785 
786     if (status != ERROR_CODE_SUCCESS){
787         printf("Responding to event 0x%02x failed with status 0x%02x\n", packet[2], status);
788     }
789 }
790 
791 static void avrcp_target_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
792     UNUSED(channel);
793     UNUSED(size);
794     uint8_t  status = ERROR_CODE_SUCCESS;
795 
796     if (packet_type != HCI_EVENT_PACKET) return;
797     if (hci_event_packet_get_type(packet) != HCI_EVENT_AVRCP_META) return;
798 
799     switch (packet[2]){
800         case AVRCP_SUBEVENT_NOTIFICATION_VOLUME_CHANGED:
801             media_tracker.volume = avrcp_subevent_notification_volume_changed_get_absolute_volume(packet);
802             printf("AVRCP Target: Volume set to %d%% (%d)\n", media_tracker.volume * 127/100, media_tracker.volume);
803             break;
804         case AVRCP_SUBEVENT_EVENT_IDS_QUERY:
805             status = avrcp_target_supported_events(media_tracker.avrcp_cid, events_num, events, sizeof(events));
806             break;
807         case AVRCP_SUBEVENT_COMPANY_IDS_QUERY:
808             status = avrcp_target_supported_companies(media_tracker.avrcp_cid, companies_num, companies, sizeof(companies));
809             break;
810         case AVRCP_SUBEVENT_PLAY_STATUS_QUERY:
811             status = avrcp_target_play_status(media_tracker.avrcp_cid, play_info.song_length_ms, play_info.song_position_ms, play_info.status);
812             break;
813         // case AVRCP_SUBEVENT_NOW_PLAYING_INFO_QUERY:
814         //     status = avrcp_target_now_playing_info(avrcp_cid);
815         //     break;
816         case AVRCP_SUBEVENT_OPERATION:{
817             avrcp_operation_id_t operation_id = avrcp_subevent_operation_get_operation_id(packet);
818             switch (operation_id){
819                 case AVRCP_OPERATION_ID_PLAY:
820                     printf("AVRCP Target: PLAY\n");
821                     status = a2dp_source_start_stream(media_tracker.a2dp_cid, media_tracker.local_seid);
822                     break;
823                 case AVRCP_OPERATION_ID_PAUSE:
824                     printf("AVRCP Target: PAUSE\n");
825                     status = a2dp_source_pause_stream(media_tracker.a2dp_cid, media_tracker.local_seid);
826                     break;
827                 case AVRCP_OPERATION_ID_STOP:
828                     printf("AVRCP Target: STOP\n");
829                     status = a2dp_source_disconnect(media_tracker.a2dp_cid);
830                     break;
831                 default:
832                     printf("AVRCP Target: operation 0x%2x is not handled\n", operation_id);
833                     return;
834             }
835             break;
836         }
837 
838         default:
839             break;
840     }
841 
842     if (status != ERROR_CODE_SUCCESS){
843         printf("Responding to event 0x%02x failed with status 0x%02x\n", packet[2], status);
844     }
845 }
846 
847 static void avrcp_controller_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
848     UNUSED(channel);
849     UNUSED(size);
850     uint8_t  status = 0xFF;
851 
852     if (packet_type != HCI_EVENT_PACKET) return;
853     if (hci_event_packet_get_type(packet) != HCI_EVENT_AVRCP_META) return;
854 
855     status = packet[5];
856     if (!media_tracker.avrcp_cid) return;
857 
858     // ignore INTERIM status
859     if (status == AVRCP_CTYPE_RESPONSE_INTERIM) return;
860 
861     switch (packet[2]){
862         case AVRCP_SUBEVENT_NOTIFICATION_VOLUME_CHANGED:
863             printf("AVRCP Controller: notification absolute volume changed %d %%\n", avrcp_subevent_notification_volume_changed_get_absolute_volume(packet) * 100 / 127);
864             break;
865         case AVRCP_SUBEVENT_GET_CAPABILITY_EVENT_ID:
866             printf("Remote supports EVENT_ID 0x%02x\n", avrcp_subevent_get_capability_event_id_get_event_id(packet));
867             break;
868         case AVRCP_SUBEVENT_GET_CAPABILITY_EVENT_ID_DONE:
869             printf("automatically enable notifications\n");
870             avrcp_controller_enable_notification(media_tracker.avrcp_cid, AVRCP_NOTIFICATION_EVENT_VOLUME_CHANGED);
871             break;
872         default:
873             break;
874     }
875 }
876 
877 #ifdef HAVE_BTSTACK_STDIN
878 static void show_usage(void){
879     bd_addr_t      iut_address;
880     gap_local_bd_addr(iut_address);
881     printf("\n--- Bluetooth  A2DP Source/AVRCP Demo %s ---\n", bd_addr_to_str(iut_address));
882     printf("b      - A2DP Source create connection to addr %s\n", device_addr_string);
883     printf("B      - A2DP Source disconnect\n");
884     printf("c      - AVRCP create connection to addr %s\n", device_addr_string);
885     printf("C      - AVRCP disconnect\n");
886     printf("D      - delete all link keys\n");
887 
888     printf("x      - start streaming sine\n");
889     if (hxcmod_initialized){
890         printf("z      - start streaming '%s'\n", mod_name);
891     }
892     printf("p      - pause streaming\n");
893     printf("w      - reconfigure stream for 44100 Hz\n");
894     printf("e      - reconfigure stream for 48000 Hz\n");
895     printf("t      - volume up\n");
896     printf("T      - volume down\n");
897     printf("v      - volume up (via set absolute volume)\n");
898     printf("V      - volume down (via set absolute volume)\n");
899 
900     printf("---\n");
901 }
902 
903 static void stdin_process(char cmd){
904     uint8_t status = ERROR_CODE_SUCCESS;
905     switch (cmd){
906         case 'b':
907             status = a2dp_source_establish_stream(device_addr, &media_tracker.a2dp_cid);
908             printf("%c - Create A2DP Source connection to addr %s, cid 0x%02x.\n", cmd, bd_addr_to_str(device_addr), media_tracker.a2dp_cid);
909             break;
910         case 'B':
911             printf("%c - A2DP Source Disconnect from cid 0x%2x\n", cmd, media_tracker.a2dp_cid);
912             status = a2dp_source_disconnect(media_tracker.a2dp_cid);
913             break;
914         case 'c':
915             printf("%c - Create AVRCP connection to addr %s.\n", cmd, bd_addr_to_str(device_addr));
916             status = avrcp_connect(device_addr, &media_tracker.avrcp_cid);
917             break;
918         case 'C':
919             printf("%c - AVRCP disconnect\n", cmd);
920             status = avrcp_disconnect(media_tracker.avrcp_cid);
921             break;
922         case 'D':
923             printf("Deleting all link keys\n");
924             gap_delete_all_link_keys();
925             break;
926         case '\n':
927         case '\r':
928             break;
929 
930         case 't':
931             printf(" - volume up\n");
932             status = avrcp_controller_volume_up(media_tracker.avrcp_cid);
933             break;
934         case 'T':
935             printf(" - volume down\n");
936             status = avrcp_controller_volume_down(media_tracker.avrcp_cid);
937             break;
938 
939         case 'v':
940             if (media_tracker.volume > 117){
941                 media_tracker.volume = 127;
942             } else {
943                 media_tracker.volume += 10;
944             }
945             printf(" - volume up (via set absolute volume) %d%% (%d)\n",  media_tracker.volume * 127/100,  media_tracker.volume);
946             status = avrcp_controller_set_absolute_volume(media_tracker.avrcp_cid, media_tracker.volume);
947             break;
948         case 'V':
949             if (media_tracker.volume < 10){
950                 media_tracker.volume = 0;
951             } else {
952                 media_tracker.volume -= 10;
953             }
954             printf(" - volume down (via set absolute volume) %d%% (%d)\n",  media_tracker.volume * 127/100,  media_tracker.volume);
955             status = avrcp_controller_set_absolute_volume(media_tracker.avrcp_cid, media_tracker.volume);
956             break;
957 
958         case 'x':
959             if (media_tracker.avrcp_cid){
960                 avrcp_target_set_now_playing_info(media_tracker.avrcp_cid, &tracks[data_source], sizeof(tracks)/sizeof(avrcp_track_t));
961             }
962             printf("%c - Play sine.\n", cmd);
963             data_source = STREAM_SINE;
964             if (!media_tracker.stream_opened) break;
965             status = a2dp_source_start_stream(media_tracker.a2dp_cid, media_tracker.local_seid);
966             break;
967         case 'z':
968             if (media_tracker.avrcp_cid){
969                 avrcp_target_set_now_playing_info(media_tracker.avrcp_cid, &tracks[data_source], sizeof(tracks)/sizeof(avrcp_track_t));
970             }
971             printf("%c - Play mod.\n", cmd);
972             data_source = STREAM_MOD;
973             if (!media_tracker.stream_opened) break;
974             status = a2dp_source_start_stream(media_tracker.a2dp_cid, media_tracker.local_seid);
975             break;
976 
977         case 'p':
978             if (!media_tracker.stream_opened) break;
979             printf("%c - Pause stream.\n", cmd);
980             status = a2dp_source_pause_stream(media_tracker.a2dp_cid, media_tracker.local_seid);
981             break;
982 
983         case 'w':
984             if (!media_tracker.stream_opened) break;
985             if (play_info.status == AVRCP_PLAYBACK_STATUS_PLAYING){
986                 printf("Stream cannot be reconfigured while playing, please pause stream first\n");
987                 break;
988             }
989             new_sample_rate = 44100;
990             if (current_sample_rate == new_sample_rate){
991                 printf("%c - Stream already configured for %d Hz.\n", cmd, new_sample_rate);
992             } else {
993                 printf("%c - Reconfigure for %d Hz.\n", cmd, new_sample_rate);
994                 status = a2dp_source_reconfigure_stream_sampling_frequency(media_tracker.a2dp_cid, new_sample_rate);
995             }
996             break;
997 
998         case 'e':
999             if (!media_tracker.stream_opened) break;
1000             if (play_info.status == AVRCP_PLAYBACK_STATUS_PLAYING){
1001                 printf("Stream cannot be reconfigured while playing, please pause stream first\n");
1002                 break;
1003             }
1004             new_sample_rate = 48000;
1005             if (current_sample_rate == new_sample_rate){
1006                 printf("%c - Stream already configured for %d Hz.\n", cmd, new_sample_rate);
1007             } else {
1008                 printf("%c - Reconfigure for %d Hz.\n", cmd, new_sample_rate);
1009                 status = a2dp_source_reconfigure_stream_sampling_frequency(media_tracker.a2dp_cid, new_sample_rate);
1010             }
1011             break;
1012 
1013         default:
1014             show_usage();
1015             return;
1016     }
1017     if (status != ERROR_CODE_SUCCESS){
1018         printf("Could not perform command \'%c\', status 0x%02x\n", cmd, status);
1019     }
1020 }
1021 #endif
1022 
1023 
1024 int btstack_main(int argc, const char * argv[]);
1025 int btstack_main(int argc, const char * argv[]){
1026     (void)argc;
1027     (void)argv;
1028 
1029     int err = a2dp_source_and_avrcp_services_init();
1030     if (err) return err;
1031     // turn on!
1032     hci_power_control(HCI_POWER_ON);
1033     return 0;
1034 }
1035 /* EXAMPLE_END */
1036