xref: /btstack/example/a2dp_source_demo.c (revision 7bbeb3ad8cec0c1816689843bf9383cf4c644ef8)
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     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 // 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 avdtp_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     a2dp_source_stream_send_media_payload(media_tracker.a2dp_cid, media_tracker.local_seid, media_tracker.sbc_storage, bytes_in_storage, num_frames, 0);
379     media_tracker.sbc_storage_count = 0;
380     media_tracker.sbc_ready_to_send = 0;
381 }
382 
383 static void produce_sine_audio(int16_t * pcm_buffer, int num_samples_to_write){
384     int count;
385     for (count = 0; count < num_samples_to_write ; count++){
386         switch (current_sample_rate){
387             case 44100:
388                 pcm_buffer[count * 2]     = sine_int16_44100[sine_phase];
389                 pcm_buffer[count * 2 + 1] = sine_int16_44100[sine_phase];
390                 sine_phase++;
391                 if (sine_phase >= num_samples_sine_int16_44100){
392                     sine_phase -= num_samples_sine_int16_44100;
393                 }
394                 break;
395             case 48000:
396                 pcm_buffer[count * 2]     = sine_int16_48000[sine_phase];
397                 pcm_buffer[count * 2 + 1] = sine_int16_48000[sine_phase];
398                 sine_phase++;
399                 if (sine_phase >= num_samples_sine_int16_48000){
400                     sine_phase -= num_samples_sine_int16_48000;
401                 }
402                 break;
403             default:
404                 break;
405         }
406     }
407 }
408 
409 static void produce_mod_audio(int16_t * pcm_buffer, int num_samples_to_write){
410     hxcmod_fillbuffer(&mod_context, (unsigned short *) &pcm_buffer[0], num_samples_to_write, &trkbuf);
411 }
412 
413 static void produce_audio(int16_t * pcm_buffer, int num_samples){
414     switch (data_source){
415         case STREAM_SINE:
416             produce_sine_audio(pcm_buffer, num_samples);
417             break;
418         case STREAM_MOD:
419             produce_mod_audio(pcm_buffer, num_samples);
420             break;
421         default:
422             break;
423     }
424 #ifdef VOLUME_REDUCTION
425     int i;
426     for (i=0;i<num_samples*2;i++){
427         if (pcm_buffer[i] > 0){
428             pcm_buffer[i] =     pcm_buffer[i]  >> VOLUME_REDUCTION;
429         } else {
430             pcm_buffer[i] = -((-pcm_buffer[i]) >> VOLUME_REDUCTION);
431         }
432     }
433 #endif
434 }
435 
436 static int a2dp_demo_fill_sbc_audio_buffer(a2dp_media_sending_context_t * context){
437     // perform sbc encoding
438     int total_num_bytes_read = 0;
439     unsigned int num_audio_samples_per_sbc_buffer = btstack_sbc_encoder_num_audio_frames();
440     while (context->samples_ready >= num_audio_samples_per_sbc_buffer
441         && (context->max_media_payload_size - context->sbc_storage_count) >= btstack_sbc_encoder_sbc_buffer_length()){
442 
443         int16_t pcm_frame[256*NUM_CHANNELS];
444 
445         produce_audio(pcm_frame, num_audio_samples_per_sbc_buffer);
446         btstack_sbc_encoder_process_data(pcm_frame);
447 
448         uint16_t sbc_frame_size = btstack_sbc_encoder_sbc_buffer_length();
449         uint8_t * sbc_frame = btstack_sbc_encoder_sbc_buffer();
450 
451         total_num_bytes_read += num_audio_samples_per_sbc_buffer;
452         memcpy(&context->sbc_storage[context->sbc_storage_count], sbc_frame, sbc_frame_size);
453         context->sbc_storage_count += sbc_frame_size;
454         context->samples_ready -= num_audio_samples_per_sbc_buffer;
455     }
456     return total_num_bytes_read;
457 }
458 
459 static void a2dp_demo_audio_timeout_handler(btstack_timer_source_t * timer){
460     a2dp_media_sending_context_t * context = (a2dp_media_sending_context_t *) btstack_run_loop_get_timer_context(timer);
461     btstack_run_loop_set_timer(&context->audio_timer, AUDIO_TIMEOUT_MS);
462     btstack_run_loop_add_timer(&context->audio_timer);
463     uint32_t now = btstack_run_loop_get_time_ms();
464 
465     uint32_t update_period_ms = AUDIO_TIMEOUT_MS;
466     if (context->time_audio_data_sent > 0){
467         update_period_ms = now - context->time_audio_data_sent;
468     }
469 
470     uint32_t num_samples = (update_period_ms * current_sample_rate) / 1000;
471     context->acc_num_missed_samples += (update_period_ms * current_sample_rate) % 1000;
472 
473     while (context->acc_num_missed_samples >= 1000){
474         num_samples++;
475         context->acc_num_missed_samples -= 1000;
476     }
477     context->time_audio_data_sent = now;
478     context->samples_ready += num_samples;
479 
480     if (context->sbc_ready_to_send) return;
481 
482     a2dp_demo_fill_sbc_audio_buffer(context);
483 
484     if ((context->sbc_storage_count + btstack_sbc_encoder_sbc_buffer_length()) > context->max_media_payload_size){
485         // schedule sending
486         context->sbc_ready_to_send = 1;
487         a2dp_source_stream_endpoint_request_can_send_now(context->a2dp_cid, context->local_seid);
488     }
489 }
490 
491 static void a2dp_demo_timer_start(a2dp_media_sending_context_t * context){
492     context->max_media_payload_size = btstack_min(a2dp_max_media_payload_size(context->a2dp_cid, context->local_seid), SBC_STORAGE_SIZE);
493     context->sbc_storage_count = 0;
494     context->sbc_ready_to_send = 0;
495     context->streaming = 1;
496     btstack_run_loop_remove_timer(&context->audio_timer);
497     btstack_run_loop_set_timer_handler(&context->audio_timer, a2dp_demo_audio_timeout_handler);
498     btstack_run_loop_set_timer_context(&context->audio_timer, context);
499     btstack_run_loop_set_timer(&context->audio_timer, AUDIO_TIMEOUT_MS);
500     btstack_run_loop_add_timer(&context->audio_timer);
501 }
502 
503 static void a2dp_demo_timer_stop(a2dp_media_sending_context_t * context){
504     context->time_audio_data_sent = 0;
505     context->acc_num_missed_samples = 0;
506     context->samples_ready = 0;
507     context->streaming = 1;
508     context->sbc_storage_count = 0;
509     context->sbc_ready_to_send = 0;
510     btstack_run_loop_remove_timer(&context->audio_timer);
511 }
512 
513 static void dump_sbc_configuration(avdtp_media_codec_configuration_sbc_t * configuration){
514     printf("Received media codec configuration:\n");
515     printf("    - num_channels: %d\n", configuration->num_channels);
516     printf("    - sampling_frequency: %d\n", configuration->sampling_frequency);
517     printf("    - channel_mode: %d\n", configuration->channel_mode);
518     printf("    - block_length: %d\n", configuration->block_length);
519     printf("    - subbands: %d\n", configuration->subbands);
520     printf("    - allocation_method: %d\n", configuration->allocation_method);
521     printf("    - bitpool_value [%d, %d] \n", configuration->min_bitpool_value, configuration->max_bitpool_value);
522 }
523 
524 static void hci_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
525     UNUSED(channel);
526     UNUSED(size);
527     if (packet_type != HCI_EVENT_PACKET) return;
528 
529 #ifndef HAVE_BTSTACK_STDIN
530     if (hci_event_packet_get_type(packet) == BTSTACK_EVENT_STATE){
531         if (btstack_event_state_get_state(packet) != HCI_STATE_WORKING) return;
532         printf("Create A2DP Source connection to addr %s.\n", bd_addr_to_str(device_addr));
533         uint8_t status = a2dp_source_establish_stream(device_addr, media_tracker.local_seid, &media_tracker.a2dp_cid);
534         if (status != ERROR_CODE_SUCCESS){
535             printf("Could not perform command, status 0x%2x\n", status);
536         }
537         return;
538     }
539 #endif
540 
541     if (hci_event_packet_get_type(packet) == HCI_EVENT_PIN_CODE_REQUEST) {
542         bd_addr_t address;
543         printf("Pin code request - using '0000'\n");
544         hci_event_pin_code_request_get_bd_addr(packet, address);
545         gap_pin_code_response(address, "0000");
546     }
547 }
548 
549 static void a2dp_source_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
550     UNUSED(channel);
551     UNUSED(size);
552     uint8_t status;
553     uint8_t local_seid;
554     bd_addr_t address;
555     uint16_t cid;
556 
557     if (packet_type != HCI_EVENT_PACKET) return;
558     if (hci_event_packet_get_type(packet) != HCI_EVENT_A2DP_META) return;
559 
560     switch (hci_event_a2dp_meta_get_subevent_code(packet)){
561         case A2DP_SUBEVENT_SIGNALING_CONNECTION_ESTABLISHED:
562             a2dp_subevent_signaling_connection_established_get_bd_addr(packet, address);
563             cid = a2dp_subevent_signaling_connection_established_get_a2dp_cid(packet);
564             status = a2dp_subevent_signaling_connection_established_get_status(packet);
565 
566             if (status != ERROR_CODE_SUCCESS){
567                 printf("A2DP Source: Connection failed, status 0x%02x, cid 0x%02x, a2dp_cid 0x%02x \n", status, cid, media_tracker.a2dp_cid);
568                 media_tracker.a2dp_cid = 0;
569                 break;
570             }
571             media_tracker.a2dp_cid = cid;
572             media_tracker.volume = 32;
573 
574             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);
575             break;
576 
577          case A2DP_SUBEVENT_SIGNALING_MEDIA_CODEC_SBC_CONFIGURATION:{
578             cid  = avdtp_subevent_signaling_media_codec_sbc_configuration_get_avdtp_cid(packet);
579             if (cid != media_tracker.a2dp_cid) return;
580 
581             media_tracker.remote_seid = a2dp_subevent_signaling_media_codec_sbc_configuration_get_acp_seid(packet);
582 
583             sbc_configuration.reconfigure = a2dp_subevent_signaling_media_codec_sbc_configuration_get_reconfigure(packet);
584             sbc_configuration.num_channels = a2dp_subevent_signaling_media_codec_sbc_configuration_get_num_channels(packet);
585             sbc_configuration.sampling_frequency = a2dp_subevent_signaling_media_codec_sbc_configuration_get_sampling_frequency(packet);
586             sbc_configuration.channel_mode = a2dp_subevent_signaling_media_codec_sbc_configuration_get_channel_mode(packet);
587             sbc_configuration.block_length = a2dp_subevent_signaling_media_codec_sbc_configuration_get_block_length(packet);
588             sbc_configuration.subbands = a2dp_subevent_signaling_media_codec_sbc_configuration_get_subbands(packet);
589             sbc_configuration.allocation_method = a2dp_subevent_signaling_media_codec_sbc_configuration_get_allocation_method(packet);
590             sbc_configuration.min_bitpool_value = a2dp_subevent_signaling_media_codec_sbc_configuration_get_min_bitpool_value(packet);
591             sbc_configuration.max_bitpool_value = a2dp_subevent_signaling_media_codec_sbc_configuration_get_max_bitpool_value(packet);
592             sbc_configuration.frames_per_buffer = sbc_configuration.subbands * sbc_configuration.block_length;
593             printf("A2DP Source: Received SBC codec configuration, sampling frequency %u, a2dp_cid 0x%02x, local seid 0x%02x, remote seid 0x%02x.\n",
594                 sbc_configuration.sampling_frequency, cid,
595                 a2dp_subevent_signaling_media_codec_sbc_configuration_get_int_seid(packet),
596                 a2dp_subevent_signaling_media_codec_sbc_configuration_get_acp_seid(packet));
597 
598             // Adapt Bluetooth spec definition to SBC Encoder expected input
599             sbc_configuration.allocation_method -= 1;
600             sbc_configuration.num_channels = 2;
601             switch (sbc_configuration.channel_mode){
602                 case AVDTP_SBC_JOINT_STEREO:
603                     sbc_configuration.channel_mode = 3;
604                     break;
605                 case AVDTP_SBC_STEREO:
606                     sbc_configuration.channel_mode = 2;
607                     break;
608                 case AVDTP_SBC_DUAL_CHANNEL:
609                     sbc_configuration.channel_mode = 1;
610                     break;
611                 case AVDTP_SBC_MONO:
612                     sbc_configuration.channel_mode = 0;
613                     sbc_configuration.num_channels = 1;
614                     break;
615                 default:
616                     btstack_assert(false);
617                     break;
618             }
619             dump_sbc_configuration(&sbc_configuration);
620 
621             btstack_sbc_encoder_init(&sbc_encoder_state, SBC_MODE_STANDARD,
622                 sbc_configuration.block_length, sbc_configuration.subbands,
623                 sbc_configuration.allocation_method, sbc_configuration.sampling_frequency,
624                 sbc_configuration.max_bitpool_value,
625                 sbc_configuration.channel_mode);
626             break;
627         }
628 
629         case A2DP_SUBEVENT_SIGNALING_DELAY_REPORTING_CAPABILITY:
630             printf("A2DP Source: remote supports delay report, remote seid %d\n",
631                 avdtp_subevent_signaling_delay_reporting_capability_get_remote_seid(packet));
632             break;
633         case A2DP_SUBEVENT_SIGNALING_CAPABILITIES_DONE:
634             printf("A2DP Source: All capabilities reported, remote seid %d\n",
635                 avdtp_subevent_signaling_capabilities_done_get_remote_seid(packet));
636             break;
637 
638         case A2DP_SUBEVENT_SIGNALING_DELAY_REPORT:
639             printf("A2DP Source: Received delay report of %d.%0d ms, local seid %d\n",
640                 avdtp_subevent_signaling_delay_report_get_delay_100us(packet)/10, avdtp_subevent_signaling_delay_report_get_delay_100us(packet)%10,
641                 avdtp_subevent_signaling_delay_report_get_local_seid(packet));
642             break;
643 
644         case A2DP_SUBEVENT_STREAM_ESTABLISHED:
645             a2dp_subevent_stream_established_get_bd_addr(packet, address);
646             status = a2dp_subevent_stream_established_get_status(packet);
647             if (status){
648                 printf("A2DP Source: Stream failed, status 0x%02x.\n", status);
649                 break;
650             }
651 
652             local_seid = a2dp_subevent_stream_established_get_local_seid(packet);
653             cid = a2dp_subevent_stream_established_get_a2dp_cid(packet);
654 
655             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));
656 
657             a2dp_demo_hexcmod_configure_sample_rate(current_sample_rate);
658             media_tracker.stream_opened = 1;
659             data_source = STREAM_MOD;
660             status = a2dp_source_start_stream(media_tracker.a2dp_cid, media_tracker.local_seid);
661             break;
662 
663         case A2DP_SUBEVENT_STREAM_RECONFIGURED:
664             status = a2dp_subevent_stream_reconfigured_get_status(packet);
665             local_seid = a2dp_subevent_stream_reconfigured_get_local_seid(packet);
666             cid = a2dp_subevent_stream_reconfigured_get_a2dp_cid(packet);
667 
668             if (status != ERROR_CODE_SUCCESS){
669                 printf("A2DP Source: Stream reconfiguration failed with status 0x%02x\n", status);
670                 break;
671             }
672 
673             printf("A2DP Source: Stream reconfigured a2dp_cid 0x%02x, local_seid 0x%02x\n", cid, local_seid);
674             a2dp_demo_hexcmod_configure_sample_rate(new_sample_rate);
675             status = a2dp_source_start_stream(media_tracker.a2dp_cid, media_tracker.local_seid);
676             break;
677 
678         case A2DP_SUBEVENT_STREAM_STARTED:
679             local_seid = a2dp_subevent_stream_started_get_local_seid(packet);
680             cid = a2dp_subevent_stream_started_get_a2dp_cid(packet);
681 
682             play_info.status = AVRCP_PLAYBACK_STATUS_PLAYING;
683             if (media_tracker.avrcp_cid){
684                 avrcp_target_set_now_playing_info(media_tracker.avrcp_cid, &tracks[data_source], sizeof(tracks)/sizeof(avrcp_track_t));
685                 avrcp_target_set_playback_status(media_tracker.avrcp_cid, AVRCP_PLAYBACK_STATUS_PLAYING);
686             }
687             a2dp_demo_timer_start(&media_tracker);
688             printf("A2DP Source: Stream started, a2dp_cid 0x%02x, local_seid 0x%02x\n", cid, local_seid);
689             break;
690 
691         case A2DP_SUBEVENT_STREAMING_CAN_SEND_MEDIA_PACKET_NOW:
692             local_seid = a2dp_subevent_streaming_can_send_media_packet_now_get_local_seid(packet);
693             cid = a2dp_subevent_signaling_media_codec_sbc_configuration_get_a2dp_cid(packet);
694             a2dp_demo_send_media_packet();
695             break;
696 
697         case A2DP_SUBEVENT_STREAM_SUSPENDED:
698             local_seid = a2dp_subevent_stream_suspended_get_local_seid(packet);
699             cid = a2dp_subevent_stream_suspended_get_a2dp_cid(packet);
700 
701             play_info.status = AVRCP_PLAYBACK_STATUS_PAUSED;
702             if (media_tracker.avrcp_cid){
703                 avrcp_target_set_playback_status(media_tracker.avrcp_cid, AVRCP_PLAYBACK_STATUS_PAUSED);
704             }
705             printf("A2DP Source: Stream paused, a2dp_cid 0x%02x, local_seid 0x%02x\n", cid, local_seid);
706 
707             a2dp_demo_timer_stop(&media_tracker);
708             break;
709 
710         case A2DP_SUBEVENT_STREAM_RELEASED:
711             play_info.status = AVRCP_PLAYBACK_STATUS_STOPPED;
712             cid = a2dp_subevent_stream_released_get_a2dp_cid(packet);
713             local_seid = a2dp_subevent_stream_released_get_local_seid(packet);
714 
715             printf("A2DP Source: Stream released, a2dp_cid 0x%02x, local_seid 0x%02x\n", cid, local_seid);
716 
717             if (cid == media_tracker.a2dp_cid) {
718                 media_tracker.stream_opened = 0;
719                 printf("A2DP Source: Stream released.\n");
720             }
721             if (media_tracker.avrcp_cid){
722                 avrcp_target_set_now_playing_info(media_tracker.avrcp_cid, NULL, sizeof(tracks)/sizeof(avrcp_track_t));
723                 avrcp_target_set_playback_status(media_tracker.avrcp_cid, AVRCP_PLAYBACK_STATUS_STOPPED);
724             }
725             a2dp_demo_timer_stop(&media_tracker);
726             break;
727         case A2DP_SUBEVENT_SIGNALING_CONNECTION_RELEASED:
728             cid = a2dp_subevent_signaling_connection_released_get_a2dp_cid(packet);
729             if (cid == media_tracker.a2dp_cid) {
730                 media_tracker.avrcp_cid = 0;
731                 media_tracker.a2dp_cid = 0;
732                 printf("A2DP Source: Signaling released.\n\n");
733             }
734             break;
735         default:
736             break;
737     }
738 }
739 
740 static void avrcp_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
741     UNUSED(channel);
742     UNUSED(size);
743     bd_addr_t event_addr;
744     uint16_t local_cid;
745     uint8_t  status = ERROR_CODE_SUCCESS;
746 
747     if (packet_type != HCI_EVENT_PACKET) return;
748     if (hci_event_packet_get_type(packet) != HCI_EVENT_AVRCP_META) return;
749 
750     switch (packet[2]){
751         case AVRCP_SUBEVENT_CONNECTION_ESTABLISHED:
752             local_cid = avrcp_subevent_connection_established_get_avrcp_cid(packet);
753             status = avrcp_subevent_connection_established_get_status(packet);
754             if (status != ERROR_CODE_SUCCESS){
755                 printf("AVRCP: Connection failed, local cid 0x%02x, status 0x%02x\n", local_cid, status);
756                 return;
757             }
758             media_tracker.avrcp_cid = local_cid;
759             avrcp_subevent_connection_established_get_bd_addr(packet, event_addr);
760 
761             avrcp_target_set_now_playing_info(media_tracker.avrcp_cid, NULL, sizeof(tracks)/sizeof(avrcp_track_t));
762             avrcp_target_set_unit_info(media_tracker.avrcp_cid, AVRCP_SUBUNIT_TYPE_AUDIO, company_id);
763             avrcp_target_set_subunit_info(media_tracker.avrcp_cid, AVRCP_SUBUNIT_TYPE_AUDIO, (uint8_t *)subunit_info, sizeof(subunit_info));
764 
765             avrcp_controller_get_supported_events(media_tracker.avrcp_cid);
766 
767             printf("AVRCP: Channel successfully opened:  media_tracker.avrcp_cid 0x%02x\n", media_tracker.avrcp_cid);
768             return;
769 
770         case AVRCP_SUBEVENT_CONNECTION_RELEASED:
771             printf("AVRCP Target: Disconnected, avrcp_cid 0x%02x\n", avrcp_subevent_connection_released_get_avrcp_cid(packet));
772             media_tracker.avrcp_cid = 0;
773             return;
774         default:
775             break;
776     }
777 
778     if (status != ERROR_CODE_SUCCESS){
779         printf("Responding to event 0x%02x failed with status 0x%02x\n", packet[2], status);
780     }
781 }
782 
783 static void avrcp_target_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
784     UNUSED(channel);
785     UNUSED(size);
786     uint8_t  status = ERROR_CODE_SUCCESS;
787 
788     if (packet_type != HCI_EVENT_PACKET) return;
789     if (hci_event_packet_get_type(packet) != HCI_EVENT_AVRCP_META) return;
790 
791     switch (packet[2]){
792         case AVRCP_SUBEVENT_NOTIFICATION_VOLUME_CHANGED:
793             media_tracker.volume = avrcp_subevent_notification_volume_changed_get_absolute_volume(packet);
794             printf("AVRCP Target: Volume set to %d%% (%d)\n", media_tracker.volume * 127/100, media_tracker.volume);
795             break;
796         case AVRCP_SUBEVENT_EVENT_IDS_QUERY:
797             status = avrcp_target_supported_events(media_tracker.avrcp_cid, events_num, events, sizeof(events));
798             break;
799         case AVRCP_SUBEVENT_COMPANY_IDS_QUERY:
800             status = avrcp_target_supported_companies(media_tracker.avrcp_cid, companies_num, companies, sizeof(companies));
801             break;
802         case AVRCP_SUBEVENT_PLAY_STATUS_QUERY:
803             status = avrcp_target_play_status(media_tracker.avrcp_cid, play_info.song_length_ms, play_info.song_position_ms, play_info.status);
804             break;
805         // case AVRCP_SUBEVENT_NOW_PLAYING_INFO_QUERY:
806         //     status = avrcp_target_now_playing_info(avrcp_cid);
807         //     break;
808         case AVRCP_SUBEVENT_OPERATION:{
809             avrcp_operation_id_t operation_id = avrcp_subevent_operation_get_operation_id(packet);
810             switch (operation_id){
811                 case AVRCP_OPERATION_ID_PLAY:
812                     printf("AVRCP Target: PLAY\n");
813                     status = a2dp_source_start_stream(media_tracker.a2dp_cid, media_tracker.local_seid);
814                     break;
815                 case AVRCP_OPERATION_ID_PAUSE:
816                     printf("AVRCP Target: PAUSE\n");
817                     status = a2dp_source_pause_stream(media_tracker.a2dp_cid, media_tracker.local_seid);
818                     break;
819                 case AVRCP_OPERATION_ID_STOP:
820                     printf("AVRCP Target: STOP\n");
821                     status = a2dp_source_disconnect(media_tracker.a2dp_cid);
822                     break;
823                 default:
824                     printf("AVRCP Target: operation 0x%2x is not handled\n", operation_id);
825                     return;
826             }
827             break;
828         }
829 
830         default:
831             break;
832     }
833 
834     if (status != ERROR_CODE_SUCCESS){
835         printf("Responding to event 0x%02x failed with status 0x%02x\n", packet[2], status);
836     }
837 }
838 
839 static void avrcp_controller_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
840     UNUSED(channel);
841     UNUSED(size);
842     uint8_t  status = 0xFF;
843 
844     if (packet_type != HCI_EVENT_PACKET) return;
845     if (hci_event_packet_get_type(packet) != HCI_EVENT_AVRCP_META) return;
846 
847     status = packet[5];
848     if (!media_tracker.avrcp_cid) return;
849 
850     // ignore INTERIM status
851     if (status == AVRCP_CTYPE_RESPONSE_INTERIM) return;
852 
853     switch (packet[2]){
854         case AVRCP_SUBEVENT_NOTIFICATION_VOLUME_CHANGED:
855             printf("AVRCP Controller: notification absolute volume changed %d %%\n", avrcp_subevent_notification_volume_changed_get_absolute_volume(packet) * 100 / 127);
856             break;
857         case AVRCP_SUBEVENT_GET_CAPABILITY_EVENT_ID:
858             printf("Remote supports EVENT_ID 0x%02x\n", avrcp_subevent_get_capability_event_id_get_event_id(packet));
859             break;
860         case AVRCP_SUBEVENT_GET_CAPABILITY_EVENT_ID_DONE:
861             printf("automatically enable notifications\n");
862             avrcp_controller_enable_notification(media_tracker.avrcp_cid, AVRCP_NOTIFICATION_EVENT_VOLUME_CHANGED);
863             break;
864         default:
865             break;
866     }
867 }
868 
869 #ifdef HAVE_BTSTACK_STDIN
870 static void show_usage(void){
871     bd_addr_t      iut_address;
872     gap_local_bd_addr(iut_address);
873     printf("\n--- Bluetooth  A2DP Source/AVRCP Demo %s ---\n", bd_addr_to_str(iut_address));
874     printf("b      - A2DP Source create connection to addr %s\n", device_addr_string);
875     printf("B      - A2DP Source disconnect\n");
876     printf("c      - AVRCP create connection to addr %s\n", device_addr_string);
877     printf("C      - AVRCP disconnect\n");
878 
879     printf("x      - start streaming sine\n");
880     if (hxcmod_initialized){
881         printf("z      - start streaming '%s'\n", mod_name);
882     }
883     printf("p      - pause streaming\n");
884     printf("w      - reconfigure stream for 44100 Hz\n");
885     printf("e      - reconfigure stream for 48000 Hz\n");
886     printf("t      - volume up\n");
887     printf("T      - volume down\n");
888     printf("v      - volume up (via set absolute volume)\n");
889     printf("V      - volume down (via set absolute volume)\n");
890 
891     printf("---\n");
892 }
893 
894 static void stdin_process(char cmd){
895     uint8_t status = ERROR_CODE_SUCCESS;
896     switch (cmd){
897         case 'b':
898             status = a2dp_source_establish_stream(device_addr, media_tracker.local_seid, &media_tracker.a2dp_cid);
899             printf("%c - Create A2DP Source connection to addr %s, cid 0x%02x.\n", cmd, bd_addr_to_str(device_addr), media_tracker.a2dp_cid);
900             break;
901         case 'B':
902             printf("%c - A2DP Source Disconnect from cid 0x%2x\n", cmd, media_tracker.a2dp_cid);
903             status = a2dp_source_disconnect(media_tracker.a2dp_cid);
904             break;
905         case 'c':
906             printf("%c - Create AVRCP connection to addr %s.\n", cmd, bd_addr_to_str(device_addr));
907             status = avrcp_connect(device_addr, &media_tracker.avrcp_cid);
908             break;
909         case 'C':
910             printf("%c - AVRCP disconnect\n", cmd);
911             status = avrcp_disconnect(media_tracker.avrcp_cid);
912             break;
913 
914         case '\n':
915         case '\r':
916             break;
917 
918         case 't':
919             printf(" - volume up\n");
920             status = avrcp_controller_volume_up(media_tracker.avrcp_cid);
921             break;
922         case 'T':
923             printf(" - volume down\n");
924             status = avrcp_controller_volume_down(media_tracker.avrcp_cid);
925             break;
926 
927         case 'v':
928             if (media_tracker.volume > 117){
929                 media_tracker.volume = 127;
930             } else {
931                 media_tracker.volume += 10;
932             }
933             printf(" - volume up (via set absolute volume) %d%% (%d)\n",  media_tracker.volume * 127/100,  media_tracker.volume);
934             status = avrcp_controller_set_absolute_volume(media_tracker.avrcp_cid, media_tracker.volume);
935             break;
936         case 'V':
937             if (media_tracker.volume < 10){
938                 media_tracker.volume = 0;
939             } else {
940                 media_tracker.volume -= 10;
941             }
942             printf(" - volume down (via set absolute volume) %d%% (%d)\n",  media_tracker.volume * 127/100,  media_tracker.volume);
943             status = avrcp_controller_set_absolute_volume(media_tracker.avrcp_cid, media_tracker.volume);
944             break;
945 
946         case 'x':
947             if (media_tracker.avrcp_cid){
948                 avrcp_target_set_now_playing_info(media_tracker.avrcp_cid, &tracks[data_source], sizeof(tracks)/sizeof(avrcp_track_t));
949             }
950             printf("%c - Play sine.\n", cmd);
951             data_source = STREAM_SINE;
952             if (!media_tracker.stream_opened) break;
953             status = a2dp_source_start_stream(media_tracker.a2dp_cid, media_tracker.local_seid);
954             break;
955         case 'z':
956             if (media_tracker.avrcp_cid){
957                 avrcp_target_set_now_playing_info(media_tracker.avrcp_cid, &tracks[data_source], sizeof(tracks)/sizeof(avrcp_track_t));
958             }
959             printf("%c - Play mod.\n", cmd);
960             data_source = STREAM_MOD;
961             if (!media_tracker.stream_opened) break;
962             status = a2dp_source_start_stream(media_tracker.a2dp_cid, media_tracker.local_seid);
963             break;
964 
965         case 'p':
966             if (!media_tracker.stream_opened) break;
967             printf("%c - Pause stream.\n", cmd);
968             status = a2dp_source_pause_stream(media_tracker.a2dp_cid, media_tracker.local_seid);
969             break;
970 
971         case 'w':
972             if (!media_tracker.stream_opened) break;
973             if (play_info.status == AVRCP_PLAYBACK_STATUS_PLAYING){
974                 printf("Stream cannot be reconfigured while playing, please pause stream first\n");
975                 break;
976             }
977             new_sample_rate = 44100;
978             if (current_sample_rate == new_sample_rate){
979                 printf("%c - Stream already configured for %d Hz.\n", cmd, new_sample_rate);
980             } else {
981                 printf("%c - Reconfigure for %d Hz.\n", cmd, new_sample_rate);
982                 status = a2dp_source_reconfigure_stream_sampling_frequency(media_tracker.a2dp_cid, new_sample_rate);
983             }
984             break;
985 
986         case 'e':
987             if (!media_tracker.stream_opened) break;
988             if (play_info.status == AVRCP_PLAYBACK_STATUS_PLAYING){
989                 printf("Stream cannot be reconfigured while playing, please pause stream first\n");
990                 break;
991             }
992             new_sample_rate = 48000;
993             if (current_sample_rate == new_sample_rate){
994                 printf("%c - Stream already configured for %d Hz.\n", cmd, new_sample_rate);
995             } else {
996                 printf("%c - Reconfigure for %d Hz.\n", cmd, new_sample_rate);
997                 status = a2dp_source_reconfigure_stream_sampling_frequency(media_tracker.a2dp_cid, new_sample_rate);
998             }
999             break;
1000 
1001         default:
1002             show_usage();
1003             return;
1004     }
1005     if (status != ERROR_CODE_SUCCESS){
1006         printf("Could not perform command \'%c\', status 0x%02x\n", cmd, status);
1007     }
1008 }
1009 #endif
1010 
1011 
1012 int btstack_main(int argc, const char * argv[]);
1013 int btstack_main(int argc, const char * argv[]){
1014     (void)argc;
1015     (void)argv;
1016 
1017     int err = a2dp_source_and_avrcp_services_init();
1018     if (err) return err;
1019     // turn on!
1020     hci_power_control(HCI_POWER_ON);
1021     return 0;
1022 }
1023 /* EXAMPLE_END */
1024