xref: /btstack/example/a2dp_source_demo.c (revision 30bfaab154dac2ac9bb506bf3eab43431dde856f)
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): Serve audio stream and handle remote playback control and queries.
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     int num_channels;
154     int sampling_frequency;
155     int channel_mode;
156     int block_length;
157     int subbands;
158     int allocation_method;
159     int min_bitpool_value;
160     int max_bitpool_value;
161     int frames_per_buffer;
162 } avdtp_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 static bd_addr_t device_addr;
179 
180 static uint8_t sdp_a2dp_source_service_buffer[150];
181 static uint8_t sdp_avrcp_target_service_buffer[200];
182 static uint8_t sdp_avrcp_controller_service_buffer[200];
183 
184 static avdtp_media_codec_configuration_sbc_t sbc_configuration;
185 static btstack_sbc_encoder_state_t sbc_encoder_state;
186 
187 static uint8_t media_sbc_codec_configuration[4];
188 static a2dp_media_sending_context_t media_tracker;
189 
190 static stream_data_source_t data_source;
191 
192 static int sine_phase;
193 static int sample_rate = 44100;
194 
195 static int hxcmod_initialized;
196 static modcontext mod_context;
197 static tracker_buffer_state trkbuf;
198 
199 /* AVRCP Target context START */
200 static const uint8_t subunit_info[] = {
201     0,0,0,0,
202     1,1,1,1,
203     2,2,2,2,
204     3,3,3,3,
205     4,4,4,4,
206     5,5,5,5,
207     6,6,6,6,
208     7,7,7,7
209 };
210 
211 static uint32_t company_id = 0x112233;
212 static uint8_t  companies_num = 1;
213 static uint8_t  companies[] = {
214     0x00, 0x19, 0x58 //BT SIG registered CompanyID
215 };
216 
217 static uint8_t events_num = 12;
218 static uint8_t events[] = {
219     AVRCP_NOTIFICATION_EVENT_PLAYBACK_STATUS_CHANGED,
220     AVRCP_NOTIFICATION_EVENT_TRACK_CHANGED,
221     AVRCP_NOTIFICATION_EVENT_TRACK_REACHED_END,
222     AVRCP_NOTIFICATION_EVENT_TRACK_REACHED_START,
223     AVRCP_NOTIFICATION_EVENT_PLAYBACK_POS_CHANGED,
224     AVRCP_NOTIFICATION_EVENT_BATT_STATUS_CHANGED,
225     AVRCP_NOTIFICATION_EVENT_SYSTEM_STATUS_CHANGED,
226     AVRCP_NOTIFICATION_EVENT_PLAYER_APPLICATION_SETTING_CHANGED,
227     AVRCP_NOTIFICATION_EVENT_NOW_PLAYING_CONTENT_CHANGED,
228     AVRCP_NOTIFICATION_EVENT_AVAILABLE_PLAYERS_CHANGED,
229     AVRCP_NOTIFICATION_EVENT_ADDRESSED_PLAYER_CHANGED,
230     AVRCP_NOTIFICATION_EVENT_UIDS_CHANGED
231 };
232 
233 typedef struct {
234     uint8_t track_id[8];
235     uint32_t song_length_ms;
236     avrcp_playback_status_t status;
237     uint32_t song_position_ms; // 0xFFFFFFFF if not supported
238 } avrcp_play_status_info_t;
239 
240 // python -c "print('a'*512)"
241 static const char title[] = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
242 
243 avrcp_track_t tracks[] = {
244     {{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01}, 1, "Sine", "Generated", "A2DP Source Demo", "monotone", 12345},
245     {{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02}, 2, "Nao-deceased", "Decease", "A2DP Source Demo", "vivid", 12345},
246     {{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03}, 3, (char *)title, "Decease", "A2DP Source Demo", "vivid", 12345},
247 };
248 int current_track_index;
249 avrcp_play_status_info_t play_info;
250 
251 /* AVRCP Target context END */
252 
253 /* @section Main Application Setup
254  *
255  * @text The Listing MainConfiguration shows how to setup AD2P Source and AVRCP services.
256  * Besides calling init() method for each service, you'll also need to register several packet handlers:
257  * - hci_packet_handler - handles legacy pairing, here by using fixed '0000' pin code.
258  * - 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).
259  * - avrcp_packet_handler - receives connect/disconnect event.
260  * - avrcp_controller_packet_handler - receives answers for sent AVRCP commands.
261  * - avrcp_target_packet_handler - receives AVRCP commands, and registered notifications.
262  * - 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.
263  *
264  * @text To announce A2DP Source and AVRCP services, you need to create corresponding
265  * SDP records and register them with the SDP service.
266  */
267 
268 /* LISTING_START(MainConfiguration): Setup Audio Source and AVRCP Target services */
269 static void hci_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
270 static void a2dp_source_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t * event, uint16_t event_size);
271 static void avrcp_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
272 static void avrcp_target_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
273 static void avrcp_controller_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
274 #ifdef HAVE_BTSTACK_STDIN
275 static void stdin_process(char cmd);
276 #endif
277 
278 static void a2dp_demo_reconfigure_sample_rate(int new_sample_rate);
279 
280 static int a2dp_source_and_avrcp_services_init(void){
281     // request role change on reconnecting headset to always use them in slave mode
282     hci_set_master_slave_policy(0);
283 
284     l2cap_init();
285     // Initialize  A2DP Source.
286     a2dp_source_init();
287     a2dp_source_register_packet_handler(&a2dp_source_packet_handler);
288 
289     // Create stream endpoint.
290     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));
291     if (!local_stream_endpoint){
292         printf("A2DP Source: not enough memory to create local stream endpoint\n");
293         return 1;
294     }
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_SF_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 = (1 << AVRCP_TARGET_SUPPORTED_FEATURE_CATEGORY_PLAYER_OR_RECORDER);
319 #ifdef AVRCP_BROWSING_ENABLED
320     supported_features |= (1 << AVRCP_TARGET_SUPPORTED_FEATURE_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     // setup AVRCP Controller
326     memset(sdp_avrcp_controller_service_buffer, 0, sizeof(sdp_avrcp_controller_service_buffer));
327     uint16_t controller_supported_features = (1 << AVRCP_CONTROLLER_SUPPORTED_FEATURE_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     // Set local name with a template Bluetooth address, that will be automatically
332     // replaced with a actual address once it is available, i.e. when BTstack boots
333     // up and starts talking to a Bluetooth module.
334     gap_set_local_name("A2DP Source 00:00:00:00:00:00");
335     gap_discoverable_control(1);
336     gap_set_class_of_device(0x200408);
337 
338     // Register for HCI events.
339     hci_event_callback_registration.callback = &hci_packet_handler;
340     hci_add_event_handler(&hci_event_callback_registration);
341 
342     a2dp_demo_reconfigure_sample_rate(sample_rate);
343 
344 #ifdef HAVE_BTSTACK_STDIN
345     // Parse human readable Bluetooth address.
346     sscanf_bd_addr(device_addr_string, device_addr);
347     btstack_stdin_setup(stdin_process);
348 #endif
349     return 0;
350 }
351 /* LISTING_END */
352 
353 static void a2dp_demo_reconfigure_sample_rate(int new_sample_rate){
354     if (!hxcmod_initialized){
355         hxcmod_initialized = hxcmod_init(&mod_context);
356         if (!hxcmod_initialized) {
357             printf("could not initialize hxcmod\n");
358             return;
359         }
360     }
361     sample_rate = new_sample_rate;
362     media_tracker.sbc_storage_count = 0;
363     media_tracker.samples_ready = 0;
364     hxcmod_unload(&mod_context);
365     hxcmod_setcfg(&mod_context, sample_rate, 16, 1, 1, 1);
366     hxcmod_load(&mod_context, (void *) &mod_data, mod_len);
367 }
368 
369 static void a2dp_demo_send_media_packet(void){
370     int num_bytes_in_frame = btstack_sbc_encoder_sbc_buffer_length();
371     int bytes_in_storage = media_tracker.sbc_storage_count;
372     uint8_t num_frames = bytes_in_storage / num_bytes_in_frame;
373     a2dp_source_stream_send_media_payload(media_tracker.a2dp_cid, media_tracker.local_seid, media_tracker.sbc_storage, bytes_in_storage, num_frames, 0);
374     media_tracker.sbc_storage_count = 0;
375     media_tracker.sbc_ready_to_send = 0;
376 }
377 
378 static void produce_sine_audio(int16_t * pcm_buffer, int num_samples_to_write){
379     int count;
380     for (count = 0; count < num_samples_to_write ; count++){
381         switch (sample_rate){
382             case 44100:
383                 pcm_buffer[count * 2]     = sine_int16_44100[sine_phase];
384                 pcm_buffer[count * 2 + 1] = sine_int16_44100[sine_phase];
385                 sine_phase++;
386                 if (sine_phase >= num_samples_sine_int16_44100){
387                     sine_phase -= num_samples_sine_int16_44100;
388                 }
389                 break;
390             case 48000:
391                 pcm_buffer[count * 2]     = sine_int16_48000[sine_phase];
392                 pcm_buffer[count * 2 + 1] = sine_int16_48000[sine_phase];
393                 sine_phase++;
394                 if (sine_phase >= num_samples_sine_int16_48000){
395                     sine_phase -= num_samples_sine_int16_48000;
396                 }
397                 break;
398             default:
399                 break;
400         }
401 
402 
403     }
404 }
405 
406 static void produce_mod_audio(int16_t * pcm_buffer, int num_samples_to_write){
407     hxcmod_fillbuffer(&mod_context, (unsigned short *) &pcm_buffer[0], num_samples_to_write, &trkbuf);
408 }
409 
410 static void produce_audio(int16_t * pcm_buffer, int num_samples){
411     switch (data_source){
412         case STREAM_SINE:
413             produce_sine_audio(pcm_buffer, num_samples);
414             break;
415         case STREAM_MOD:
416             produce_mod_audio(pcm_buffer, num_samples);
417             break;
418         default:
419             break;
420     }
421 #ifdef VOLUME_REDUCTION
422     int i;
423     for (i=0;i<num_samples*2;i++){
424         if (pcm_buffer[i] > 0){
425             pcm_buffer[i] =     pcm_buffer[i]  >> VOLUME_REDUCTION;
426         } else {
427             pcm_buffer[i] = -((-pcm_buffer[i]) >> VOLUME_REDUCTION);
428         }
429     }
430 #endif
431 }
432 
433 static int a2dp_demo_fill_sbc_audio_buffer(a2dp_media_sending_context_t * context){
434     // perform sbc encodin
435     int total_num_bytes_read = 0;
436     unsigned int num_audio_samples_per_sbc_buffer = btstack_sbc_encoder_num_audio_frames();
437     while (context->samples_ready >= num_audio_samples_per_sbc_buffer
438         && (context->max_media_payload_size - context->sbc_storage_count) >= btstack_sbc_encoder_sbc_buffer_length()){
439 
440         int16_t pcm_frame[256*NUM_CHANNELS];
441 
442         produce_audio(pcm_frame, num_audio_samples_per_sbc_buffer);
443         btstack_sbc_encoder_process_data(pcm_frame);
444 
445         uint16_t sbc_frame_size = btstack_sbc_encoder_sbc_buffer_length();
446         uint8_t * sbc_frame = btstack_sbc_encoder_sbc_buffer();
447 
448         total_num_bytes_read += num_audio_samples_per_sbc_buffer;
449         memcpy(&context->sbc_storage[context->sbc_storage_count], sbc_frame, sbc_frame_size);
450         context->sbc_storage_count += sbc_frame_size;
451         context->samples_ready -= num_audio_samples_per_sbc_buffer;
452     }
453     return total_num_bytes_read;
454 }
455 
456 static void a2dp_demo_audio_timeout_handler(btstack_timer_source_t * timer){
457     a2dp_media_sending_context_t * context = (a2dp_media_sending_context_t *) btstack_run_loop_get_timer_context(timer);
458     btstack_run_loop_set_timer(&context->audio_timer, AUDIO_TIMEOUT_MS);
459     btstack_run_loop_add_timer(&context->audio_timer);
460     uint32_t now = btstack_run_loop_get_time_ms();
461 
462     uint32_t update_period_ms = AUDIO_TIMEOUT_MS;
463     if (context->time_audio_data_sent > 0){
464         update_period_ms = now - context->time_audio_data_sent;
465     }
466 
467     uint32_t num_samples = (update_period_ms * sample_rate) / 1000;
468     context->acc_num_missed_samples += (update_period_ms * sample_rate) % 1000;
469 
470     while (context->acc_num_missed_samples >= 1000){
471         num_samples++;
472         context->acc_num_missed_samples -= 1000;
473     }
474     context->time_audio_data_sent = now;
475     context->samples_ready += num_samples;
476 
477     if (context->sbc_ready_to_send) return;
478 
479     a2dp_demo_fill_sbc_audio_buffer(context);
480 
481     if ((context->sbc_storage_count + btstack_sbc_encoder_sbc_buffer_length()) > context->max_media_payload_size){
482         // schedule sending
483         context->sbc_ready_to_send = 1;
484         a2dp_source_stream_endpoint_request_can_send_now(context->a2dp_cid, context->local_seid);
485     }
486 }
487 
488 static void a2dp_demo_timer_start(a2dp_media_sending_context_t * context){
489     context->max_media_payload_size = btstack_min(a2dp_max_media_payload_size(context->a2dp_cid, context->local_seid), SBC_STORAGE_SIZE);
490     context->sbc_storage_count = 0;
491     context->sbc_ready_to_send = 0;
492     context->streaming = 1;
493     btstack_run_loop_remove_timer(&context->audio_timer);
494     btstack_run_loop_set_timer_handler(&context->audio_timer, a2dp_demo_audio_timeout_handler);
495     btstack_run_loop_set_timer_context(&context->audio_timer, context);
496     btstack_run_loop_set_timer(&context->audio_timer, AUDIO_TIMEOUT_MS);
497     btstack_run_loop_add_timer(&context->audio_timer);
498 }
499 
500 static void a2dp_demo_timer_stop(a2dp_media_sending_context_t * context){
501     context->time_audio_data_sent = 0;
502     context->acc_num_missed_samples = 0;
503     context->samples_ready = 0;
504     context->streaming = 1;
505     context->sbc_storage_count = 0;
506     context->sbc_ready_to_send = 0;
507     btstack_run_loop_remove_timer(&context->audio_timer);
508 }
509 
510 static void dump_sbc_configuration(avdtp_media_codec_configuration_sbc_t * configuration){
511     printf("Received media codec configuration:\n");
512     printf("    - num_channels: %d\n", configuration->num_channels);
513     printf("    - sampling_frequency: %d\n", configuration->sampling_frequency);
514     printf("    - channel_mode: %d\n", configuration->channel_mode);
515     printf("    - block_length: %d\n", configuration->block_length);
516     printf("    - subbands: %d\n", configuration->subbands);
517     printf("    - allocation_method: %d\n", configuration->allocation_method);
518     printf("    - bitpool_value [%d, %d] \n", configuration->min_bitpool_value, configuration->max_bitpool_value);
519 }
520 
521 static void hci_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
522     UNUSED(channel);
523     UNUSED(size);
524     if (packet_type != HCI_EVENT_PACKET) return;
525 
526 #ifndef HAVE_BTSTACK_STDIN
527     if (hci_event_packet_get_type(packet) == BTSTACK_EVENT_STATE){
528         if (btstack_event_state_get_state(packet) != HCI_STATE_WORKING) return;
529         printf("Create A2DP Source connection to addr %s.\n", bd_addr_to_str(device_addr));
530         uint8_t status = a2dp_source_establish_stream(device_addr, media_tracker.local_seid, &media_tracker.a2dp_cid);
531         if (status != ERROR_CODE_SUCCESS){
532             printf("Could not perform command, status 0x%2x\n", status);
533         }
534         return;
535     }
536 #endif
537 
538     if (hci_event_packet_get_type(packet) == HCI_EVENT_PIN_CODE_REQUEST) {
539         bd_addr_t address;
540         printf("Pin code request - using '0000'\n");
541         hci_event_pin_code_request_get_bd_addr(packet, address);
542         gap_pin_code_response(address, "0000");
543     }
544 }
545 
546 static void a2dp_source_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
547     UNUSED(channel);
548     UNUSED(size);
549     uint8_t status;
550     uint8_t local_seid;
551     bd_addr_t address;
552     uint16_t cid;
553 
554     if (packet_type != HCI_EVENT_PACKET) return;
555     if (hci_event_packet_get_type(packet) != HCI_EVENT_A2DP_META) return;
556 
557     switch (hci_event_a2dp_meta_get_subevent_code(packet)){
558         case A2DP_SUBEVENT_SIGNALING_CONNECTION_ESTABLISHED:
559             a2dp_subevent_signaling_connection_established_get_bd_addr(packet, address);
560             cid = a2dp_subevent_signaling_connection_established_get_a2dp_cid(packet);
561             status = a2dp_subevent_signaling_connection_established_get_status(packet);
562 
563             if (status != ERROR_CODE_SUCCESS){
564                 printf("A2DP Source: Connection failed, status 0x%02x, cid 0x%02x, a2dp_cid 0x%02x \n", status, cid, media_tracker.a2dp_cid);
565                 media_tracker.a2dp_cid = 0;
566                 break;
567             }
568             media_tracker.a2dp_cid = cid;
569             media_tracker.volume = 64;
570 
571             printf("A2DP Source: Connected to address %s, a2dp cid 0x%02x, local seid %d.\n", bd_addr_to_str(address), media_tracker.a2dp_cid, media_tracker.local_seid);
572             break;
573 
574          case A2DP_SUBEVENT_SIGNALING_MEDIA_CODEC_SBC_CONFIGURATION:{
575             cid  = avdtp_subevent_signaling_media_codec_sbc_configuration_get_avdtp_cid(packet);
576             if (cid != media_tracker.a2dp_cid) return;
577             media_tracker.remote_seid = a2dp_subevent_signaling_media_codec_sbc_configuration_get_acp_seid(packet);
578 
579             sbc_configuration.reconfigure = a2dp_subevent_signaling_media_codec_sbc_configuration_get_reconfigure(packet);
580             sbc_configuration.num_channels = a2dp_subevent_signaling_media_codec_sbc_configuration_get_num_channels(packet);
581             sbc_configuration.sampling_frequency = a2dp_subevent_signaling_media_codec_sbc_configuration_get_sampling_frequency(packet);
582             sbc_configuration.channel_mode = a2dp_subevent_signaling_media_codec_sbc_configuration_get_channel_mode(packet);
583             sbc_configuration.block_length = a2dp_subevent_signaling_media_codec_sbc_configuration_get_block_length(packet);
584             sbc_configuration.subbands = a2dp_subevent_signaling_media_codec_sbc_configuration_get_subbands(packet);
585             sbc_configuration.allocation_method = a2dp_subevent_signaling_media_codec_sbc_configuration_get_allocation_method(packet);
586             sbc_configuration.min_bitpool_value = a2dp_subevent_signaling_media_codec_sbc_configuration_get_min_bitpool_value(packet);
587             sbc_configuration.max_bitpool_value = a2dp_subevent_signaling_media_codec_sbc_configuration_get_max_bitpool_value(packet);
588             sbc_configuration.frames_per_buffer = sbc_configuration.subbands * sbc_configuration.block_length;
589             printf("A2DP Source: Received SBC codec configuration, sampling frequency %u, a2dp_cid 0x%02x, local seid %d (expected %d), remote seid %d .\n",
590                 sbc_configuration.sampling_frequency, cid,
591                 a2dp_subevent_signaling_media_codec_sbc_configuration_get_int_seid(packet),
592                 media_tracker.local_seid,
593                 media_tracker.remote_seid);
594 
595             // Adapt Bluetooth spec definition to SBC Encoder expected input
596             sbc_configuration.allocation_method -= 1;
597             sbc_configuration.num_channels = 2;
598             switch (sbc_configuration.channel_mode){
599                 case AVDTP_SBC_JOINT_STEREO:
600                     sbc_configuration.channel_mode = 3;
601                     break;
602                 case AVDTP_SBC_STEREO:
603                     sbc_configuration.channel_mode = 2;
604                     break;
605                 case AVDTP_SBC_DUAL_CHANNEL:
606                     sbc_configuration.channel_mode = 1;
607                     break;
608                 case AVDTP_SBC_MONO:
609                     sbc_configuration.channel_mode = 0;
610                     sbc_configuration.num_channels = 1;
611                     break;
612             }
613             dump_sbc_configuration(&sbc_configuration);
614 
615             btstack_sbc_encoder_init(&sbc_encoder_state, SBC_MODE_STANDARD,
616                 sbc_configuration.block_length, sbc_configuration.subbands,
617                 sbc_configuration.allocation_method, sbc_configuration.sampling_frequency,
618                 sbc_configuration.max_bitpool_value,
619                 sbc_configuration.channel_mode);
620             break;
621         }
622 
623         case A2DP_SUBEVENT_SIGNALING_DELAY_REPORTING_CAPABILITY:
624             printf("A2DP Source: remote supports delay report, remote seid %d\n",
625                 avdtp_subevent_signaling_delay_reporting_capability_get_remote_seid(packet));
626             break;
627         case A2DP_SUBEVENT_SIGNALING_CAPABILITIES_DONE:
628             printf("A2DP Source: All capabilities reported, remote seid %d\n",
629                 avdtp_subevent_signaling_capabilities_done_get_remote_seid(packet));
630             break;
631 
632         case A2DP_SUBEVENT_SIGNALING_DELAY_REPORT:
633             printf("A2DP Source: Received delay report of %d.%0d ms, local seid %d\n",
634                 avdtp_subevent_signaling_delay_report_get_delay_100us(packet)/10, avdtp_subevent_signaling_delay_report_get_delay_100us(packet)%10,
635                 avdtp_subevent_signaling_delay_report_get_local_seid(packet));
636             break;
637 
638         case A2DP_SUBEVENT_STREAM_ESTABLISHED:
639             a2dp_subevent_stream_established_get_bd_addr(packet, address);
640             status = a2dp_subevent_stream_established_get_status(packet);
641             if (status){
642                 printf("A2DP Source: Stream failed, status 0x%02x.\n", status);
643                 break;
644             }
645 
646             local_seid = a2dp_subevent_stream_established_get_local_seid(packet);
647             cid = a2dp_subevent_stream_established_get_a2dp_cid(packet);
648             printf("A2DP_SUBEVENT_STREAM_ESTABLISHED:  a2dp_cid [expected 0x%02x, received 0x%02x], local_seid %d (expected %d), remote_seid %d (expected %d)\n",
649                      media_tracker.a2dp_cid, cid,
650                      local_seid, media_tracker.local_seid,
651                      a2dp_subevent_stream_established_get_remote_seid(packet), media_tracker.remote_seid);
652 
653             if (local_seid != media_tracker.local_seid){
654                 printf("A2DP Source: Stream failed, wrong local seid %d, expected %d.\n", local_seid, media_tracker.local_seid);
655                 break;
656             }
657             printf("A2DP Source: Stream established, address %s, a2dp cid 0x%02x, local seid %d, remote seid %d.\n", bd_addr_to_str(address),
658                 media_tracker.a2dp_cid, media_tracker.local_seid, a2dp_subevent_stream_established_get_remote_seid(packet));
659             media_tracker.stream_opened = 1;
660             data_source = STREAM_MOD;
661             status = a2dp_source_start_stream(media_tracker.a2dp_cid, media_tracker.local_seid);
662             break;
663 
664         case A2DP_SUBEVENT_STREAM_RECONFIGURED:
665             status = a2dp_subevent_stream_reconfigured_get_status(packet);
666             local_seid = a2dp_subevent_stream_reconfigured_get_local_seid(packet);
667             cid = a2dp_subevent_stream_reconfigured_get_a2dp_cid(packet);
668 
669             printf("A2DP Source: Reconfigured: a2dp_cid [expected 0x%02x, received 0x%02x], local_seid [expected %d, received %d]\n", media_tracker.a2dp_cid, cid, media_tracker.local_seid, local_seid);
670             printf("Status 0x%02x\n", status);
671             break;
672 
673         case A2DP_SUBEVENT_STREAM_STARTED:
674             local_seid = a2dp_subevent_stream_started_get_local_seid(packet);
675             cid = a2dp_subevent_stream_started_get_a2dp_cid(packet);
676 
677             play_info.status = AVRCP_PLAYBACK_STATUS_PLAYING;
678             if (media_tracker.avrcp_cid){
679                 avrcp_target_set_now_playing_info(media_tracker.avrcp_cid, &tracks[data_source], sizeof(tracks)/sizeof(avrcp_track_t));
680                 avrcp_target_set_playback_status(media_tracker.avrcp_cid, AVRCP_PLAYBACK_STATUS_PLAYING);
681             }
682             a2dp_demo_timer_start(&media_tracker);
683             printf("A2DP Source: Stream started: a2dp_cid [expected 0x%02x, received 0x%02x], local_seid [expected %d, received %d]\n", media_tracker.a2dp_cid, cid, media_tracker.local_seid, local_seid);
684             break;
685 
686         case A2DP_SUBEVENT_STREAMING_CAN_SEND_MEDIA_PACKET_NOW:
687             local_seid = a2dp_subevent_streaming_can_send_media_packet_now_get_local_seid(packet);
688             cid = a2dp_subevent_signaling_media_codec_sbc_configuration_get_a2dp_cid(packet);
689             // printf("A2DP Source: can send media packet: a2dp_cid [expected 0x%02x, received 0x%02x], local_seid [expected %d, received %d]\n", media_tracker.a2dp_cid, cid, media_tracker.local_seid, local_seid);
690             a2dp_demo_send_media_packet();
691             break;
692 
693         case A2DP_SUBEVENT_STREAM_SUSPENDED:
694             local_seid = a2dp_subevent_stream_suspended_get_local_seid(packet);
695             cid = a2dp_subevent_stream_suspended_get_a2dp_cid(packet);
696 
697             play_info.status = AVRCP_PLAYBACK_STATUS_PAUSED;
698             if (media_tracker.avrcp_cid){
699                 avrcp_target_set_playback_status(media_tracker.avrcp_cid, AVRCP_PLAYBACK_STATUS_PAUSED);
700             }
701             printf("A2DP Source: Stream paused: a2dp_cid [expected 0x%02x, received 0x%02x], local_seid [expected %d, received %d]\n", media_tracker.a2dp_cid, cid, media_tracker.local_seid, local_seid);
702 
703             a2dp_demo_timer_stop(&media_tracker);
704             break;
705 
706         case A2DP_SUBEVENT_STREAM_RELEASED:
707             play_info.status = AVRCP_PLAYBACK_STATUS_STOPPED;
708             cid = a2dp_subevent_stream_released_get_a2dp_cid(packet);
709             local_seid = a2dp_subevent_stream_released_get_local_seid(packet);
710 
711             printf("A2DP Source: Stream released: a2dp_cid [expected 0x%02x, received 0x%02x], local_seid [expected %d, received %d]\n", media_tracker.a2dp_cid, cid, media_tracker.local_seid, local_seid);
712 
713             if (cid == media_tracker.a2dp_cid) {
714                 media_tracker.stream_opened = 0;
715                 printf("A2DP Source: Stream released.\n");
716             }
717             if (media_tracker.avrcp_cid){
718                 avrcp_target_set_now_playing_info(media_tracker.avrcp_cid, NULL, sizeof(tracks)/sizeof(avrcp_track_t));
719                 avrcp_target_set_playback_status(media_tracker.avrcp_cid, AVRCP_PLAYBACK_STATUS_STOPPED);
720             }
721 
722             a2dp_demo_timer_stop(&media_tracker);
723             break;
724         case A2DP_SUBEVENT_SIGNALING_CONNECTION_RELEASED:
725             cid = a2dp_subevent_signaling_connection_released_get_a2dp_cid(packet);
726             if (cid == media_tracker.a2dp_cid) {
727                 media_tracker.avrcp_cid = 0;
728                 media_tracker.a2dp_cid = 0;
729                 printf("A2DP Source: Signaling released.\n\n");
730             }
731             break;
732         default:
733             break;
734     }
735 }
736 
737 static void avrcp_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
738     UNUSED(channel);
739     UNUSED(size);
740     bd_addr_t event_addr;
741     uint16_t local_cid;
742     uint8_t  status = ERROR_CODE_SUCCESS;
743 
744     if (packet_type != HCI_EVENT_PACKET) return;
745     if (hci_event_packet_get_type(packet) != HCI_EVENT_AVRCP_META) return;
746 
747     switch (packet[2]){
748         case AVRCP_SUBEVENT_CONNECTION_ESTABLISHED:
749             local_cid = avrcp_subevent_connection_established_get_avrcp_cid(packet);
750             status = avrcp_subevent_connection_established_get_status(packet);
751             if (status != ERROR_CODE_SUCCESS){
752                 printf("AVRCP: Connection failed, local cid 0x%02x, status 0x%02x\n", local_cid, status);
753                 return;
754             }
755             media_tracker.avrcp_cid = local_cid;
756             avrcp_subevent_connection_established_get_bd_addr(packet, event_addr);
757 
758             avrcp_target_set_now_playing_info(media_tracker.avrcp_cid, NULL, sizeof(tracks)/sizeof(avrcp_track_t));
759             avrcp_target_set_unit_info(media_tracker.avrcp_cid, AVRCP_SUBUNIT_TYPE_AUDIO, company_id);
760             avrcp_target_set_subunit_info(media_tracker.avrcp_cid, AVRCP_SUBUNIT_TYPE_AUDIO, (uint8_t *)subunit_info, sizeof(subunit_info));
761 
762             // automatically enable notifications
763             avrcp_controller_enable_notification(media_tracker.avrcp_cid, AVRCP_NOTIFICATION_EVENT_VOLUME_CHANGED);
764             printf("AVRCP: Channel successfully opened:  media_tracker.avrcp_cid 0x%02x\n", media_tracker.avrcp_cid);
765             return;
766 
767         case AVRCP_SUBEVENT_CONNECTION_RELEASED:
768             printf("AVRCP Target: Disconnected, avrcp_cid 0x%02x\n", avrcp_subevent_connection_released_get_avrcp_cid(packet));
769             media_tracker.avrcp_cid = 0;
770             return;
771         default:
772             break;
773     }
774 
775     if (status != ERROR_CODE_SUCCESS){
776         printf("Responding to event 0x%02x failed with status 0x%02x\n", packet[2], status);
777     }
778 }
779 
780 static void avrcp_target_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
781     UNUSED(channel);
782     UNUSED(size);
783     uint8_t  status = ERROR_CODE_SUCCESS;
784 
785     if (packet_type != HCI_EVENT_PACKET) return;
786     if (hci_event_packet_get_type(packet) != HCI_EVENT_AVRCP_META) return;
787 
788     switch (packet[2]){
789         case AVRCP_SUBEVENT_NOTIFICATION_VOLUME_CHANGED:
790             media_tracker.volume = avrcp_subevent_notification_volume_changed_get_absolute_volume(packet);
791             printf("AVRCP Target: Volume set to %d%% (%d)\n", media_tracker.volume * 127/100, media_tracker.volume);
792             break;
793         case AVRCP_SUBEVENT_EVENT_IDS_QUERY:
794             status = avrcp_target_supported_events(media_tracker.avrcp_cid, events_num, events, sizeof(events));
795             break;
796         case AVRCP_SUBEVENT_COMPANY_IDS_QUERY:
797             status = avrcp_target_supported_companies(media_tracker.avrcp_cid, companies_num, companies, sizeof(companies));
798             break;
799         case AVRCP_SUBEVENT_PLAY_STATUS_QUERY:
800             status = avrcp_target_play_status(media_tracker.avrcp_cid, play_info.song_length_ms, play_info.song_position_ms, play_info.status);
801             break;
802         // case AVRCP_SUBEVENT_NOW_PLAYING_INFO_QUERY:
803         //     status = avrcp_target_now_playing_info(avrcp_cid);
804         //     break;
805         case AVRCP_SUBEVENT_OPERATION:{
806             avrcp_operation_id_t operation_id = avrcp_subevent_operation_get_operation_id(packet);
807             switch (operation_id){
808                 case AVRCP_OPERATION_ID_PLAY:
809                     printf("AVRCP Target: PLAY\n");
810                     status = a2dp_source_start_stream(media_tracker.a2dp_cid, media_tracker.local_seid);
811                     break;
812                 case AVRCP_OPERATION_ID_PAUSE:
813                     printf("AVRCP Target: PAUSE\n");
814                     status = a2dp_source_pause_stream(media_tracker.a2dp_cid, media_tracker.local_seid);
815                     break;
816                 case AVRCP_OPERATION_ID_STOP:
817                     printf("AVRCP Target: STOP\n");
818                     status = a2dp_source_disconnect(media_tracker.a2dp_cid);
819                     break;
820                 default:
821                     printf("AVRCP Target: operation 0x%2x is not handled\n", operation_id);
822                     return;
823             }
824             break;
825         }
826 
827         default:
828             break;
829     }
830 
831     if (status != ERROR_CODE_SUCCESS){
832         printf("Responding to event 0x%02x failed with status 0x%02x\n", packet[2], status);
833     }
834 }
835 
836 static void avrcp_controller_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
837     UNUSED(channel);
838     UNUSED(size);
839     uint8_t  status = 0xFF;
840 
841     if (packet_type != HCI_EVENT_PACKET) return;
842     if (hci_event_packet_get_type(packet) != HCI_EVENT_AVRCP_META) return;
843 
844     status = packet[5];
845     if (!media_tracker.avrcp_cid) return;
846 
847     // ignore INTERIM status
848     if (status == AVRCP_CTYPE_RESPONSE_INTERIM) return;
849 
850     switch (packet[2]){
851         case AVRCP_SUBEVENT_NOTIFICATION_VOLUME_CHANGED:{
852             int volume_percentage = avrcp_subevent_notification_volume_changed_get_absolute_volume(packet) * 100 / 127;
853             printf("AVRCP Controller: notification absolute volume changed %d %%\n", volume_percentage);
854             return;
855         }
856         default:
857             break;
858     }
859 }
860 
861 #ifdef HAVE_BTSTACK_STDIN
862 static void show_usage(void){
863     bd_addr_t      iut_address;
864     gap_local_bd_addr(iut_address);
865     printf("\n--- Bluetooth  A2DP Source/AVRCP Demo %s ---\n", bd_addr_to_str(iut_address));
866     printf("b      - A2DP Source create connection to addr %s\n", device_addr_string);
867     printf("B      - A2DP Source disconnect\n");
868     printf("c      - AVRCP create connection to addr %s\n", device_addr_string);
869     printf("C      - AVRCP disconnect\n");
870 
871     printf("x      - start streaming sine\n");
872     if (hxcmod_initialized){
873         printf("z      - start streaming '%s'\n", mod_name);
874     }
875     printf("p      - pause streaming\n");
876     printf("w      - reconfigure stream for 44100 Hz\n");
877     printf("e      - reconfigure stream for 48000 Hz\n");
878     printf("t      - volume up\n");
879     printf("T      - volume down\n");
880     printf("v      - volume up (via set absolute volume)\n");
881     printf("V      - volume down (via set absolute volume)\n");
882 
883     printf("---\n");
884 }
885 
886 static void stdin_process(char cmd){
887     uint8_t status = ERROR_CODE_SUCCESS;
888     switch (cmd){
889         case 'b':
890             status = a2dp_source_establish_stream(device_addr, media_tracker.local_seid, &media_tracker.a2dp_cid);
891             printf("%c - Create A2DP Source connection to addr %s, cid 0x%02x.\n", cmd, bd_addr_to_str(device_addr), media_tracker.a2dp_cid);
892             break;
893         case 'B':
894             printf("%c - A2DP Source Disconnect from cid 0x%2x\n", cmd, media_tracker.a2dp_cid);
895             status = a2dp_source_disconnect(media_tracker.a2dp_cid);
896             break;
897         case 'c':
898             printf("%c - Create AVRCP connection to addr %s.\n", cmd, bd_addr_to_str(device_addr));
899             status = avrcp_connect(device_addr, &media_tracker.avrcp_cid);
900             break;
901         case 'C':
902             printf("%c - AVRCP disconnect\n", cmd);
903             status = avrcp_disconnect(media_tracker.avrcp_cid);
904             break;
905 
906         case '\n':
907         case '\r':
908             break;
909 
910         case 't':
911             printf(" - volume up\n");
912             status = avrcp_controller_volume_up(media_tracker.avrcp_cid);
913             break;
914         case 'T':
915             printf(" - volume down\n");
916             status = avrcp_controller_volume_down(media_tracker.avrcp_cid);
917             break;
918 
919         case 'v':
920             if (media_tracker.volume > 117){
921                 media_tracker.volume = 127;
922             } else {
923                 media_tracker.volume += 10;
924             }
925             printf(" - volume up (via set absolute volume) %d%% (%d)\n",  media_tracker.volume * 127/100,  media_tracker.volume);
926             status = avrcp_controller_set_absolute_volume(media_tracker.avrcp_cid, media_tracker.volume);
927             break;
928         case 'V':
929             if (media_tracker.volume < 10){
930                 media_tracker.volume = 0;
931             } else {
932                 media_tracker.volume -= 10;
933             }
934             printf(" - volume down (via set absolute volume) %d%% (%d)\n",  media_tracker.volume * 127/100,  media_tracker.volume);
935             status = avrcp_controller_set_absolute_volume(media_tracker.avrcp_cid, media_tracker.volume);
936             break;
937 
938         case 'x':
939             if (media_tracker.avrcp_cid){
940                 avrcp_target_set_now_playing_info(media_tracker.avrcp_cid, &tracks[data_source], sizeof(tracks)/sizeof(avrcp_track_t));
941             }
942             printf("%c - Play sine.\n", cmd);
943             data_source = STREAM_SINE;
944             if (!media_tracker.stream_opened) break;
945             status = a2dp_source_start_stream(media_tracker.a2dp_cid, media_tracker.local_seid);
946             break;
947         case 'z':
948             if (media_tracker.avrcp_cid){
949                 avrcp_target_set_now_playing_info(media_tracker.avrcp_cid, &tracks[data_source], sizeof(tracks)/sizeof(avrcp_track_t));
950             }
951             printf("%c - Play mod.\n", cmd);
952             data_source = STREAM_MOD;
953             if (!media_tracker.stream_opened) break;
954             status = a2dp_source_start_stream(media_tracker.a2dp_cid, media_tracker.local_seid);
955             if (status == ERROR_CODE_SUCCESS){
956                 a2dp_demo_reconfigure_sample_rate(sample_rate);
957             }
958             break;
959 
960         case 'p':
961             if (!media_tracker.stream_opened) break;
962             printf("%c - Pause stream.\n", cmd);
963             status = a2dp_source_pause_stream(media_tracker.a2dp_cid, media_tracker.local_seid);
964             break;
965 
966         case 'w':
967             if (!media_tracker.stream_opened) break;
968             if (play_info.status == AVRCP_PLAYBACK_STATUS_PLAYING){
969                 printf("Stream cannot be reconfigured while playing, please pause stream first\n");
970                 break;
971             }
972             printf("%c - Reconfigure for %d Hz.\n", cmd, sample_rate);
973             status = a2dp_source_reconfigure_stream_sampling_frequency(media_tracker.a2dp_cid, 44100);
974             if (status == ERROR_CODE_SUCCESS){
975                 a2dp_demo_reconfigure_sample_rate(44100);
976             }
977             break;
978 
979         case 'e':
980             if (!media_tracker.stream_opened) break;
981             if (play_info.status == AVRCP_PLAYBACK_STATUS_PLAYING){
982                 printf("Stream cannot be reconfigured while playing, please pause stream first\n");
983                 break;
984             }
985             printf("%c - Reconfigure for %d Hz.\n", cmd, sample_rate);
986             status = a2dp_source_reconfigure_stream_sampling_frequency(media_tracker.a2dp_cid, 48000);
987             if (status == ERROR_CODE_SUCCESS){
988                 a2dp_demo_reconfigure_sample_rate(48000);
989             }
990             break;
991 
992         default:
993             show_usage();
994             return;
995     }
996     if (status != ERROR_CODE_SUCCESS){
997         printf("Could not perform command \'%c\', status 0x%02x\n", cmd, status);
998     }
999 }
1000 #endif
1001 
1002 
1003 int btstack_main(int argc, const char * argv[]);
1004 int btstack_main(int argc, const char * argv[]){
1005     (void)argc;
1006     (void)argv;
1007 
1008     int err = a2dp_source_and_avrcp_services_init();
1009     if (err) return err;
1010     // turn on!
1011     hci_power_control(HCI_POWER_ON);
1012     return 0;
1013 }
1014 /* EXAMPLE_END */
1015