xref: /btstack/example/a2dp_sink_demo.c (revision 4930cef6e21e6da2d7571b9259c7f0fb8bed3d01)
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 BLUEKITCHEN
24  * GMBH 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_sink_demo.c"
39 
40 /*
41  * a2dp_sink_demo.c
42  */
43 
44 // *****************************************************************************
45 /* EXAMPLE_START(a2dp_sink_demo): A2DP Sink - Receive Audio Stream and Control Playback
46  *
47  * @text This A2DP Sink example demonstrates how to use the A2DP Sink service to
48  * receive an audio data stream from a remote A2DP Source device. In addition,
49  * the AVRCP Controller is used to get information on currently played media,
50  * such are title, artist and album, as well as to control the playback,
51  * i.e. to play, stop, repeat, etc. If HAVE_BTSTACK_STDIN is set, press SPACE on
52  * the console to show the available AVDTP and AVRCP commands.
53  *
54  * @text To test with a remote device, e.g. a mobile phone,
55  * pair from the remote device with the demo, then start playing music on the remote device.
56  * Alternatively, set the device_addr_string to the Bluetooth address of your
57  * remote device in the code, and call connect from the UI.
58  *
59  * @text For more info on BTstack audio, see our blog post
60  * [A2DP Sink and Source on STM32 F4 Discovery Board](http://bluekitchen-gmbh.com/a2dp-sink-and-source-on-stm32-f4-discovery-board/).
61  *
62  */
63 // *****************************************************************************
64 
65 #include <inttypes.h>
66 #include <stdint.h>
67 #include <stdio.h>
68 #include <stdlib.h>
69 #include <string.h>
70 
71 #include "btstack.h"
72 #include "btstack_resample.h"
73 
74 //#define AVRCP_BROWSING_ENABLED
75 
76 // if volume control not supported by btstack_audio_sink, you can try to disable volume change notification
77 // to force the A2DP Source to reduce volume by attenuating the audio stream
78 #define SUPPORT_VOLUME_CHANGE_NOTIFICATION
79 
80 #ifdef HAVE_BTSTACK_STDIN
81 #include "btstack_stdin.h"
82 #endif
83 
84 #include "btstack_ring_buffer.h"
85 
86 #ifdef HAVE_POSIX_FILE_IO
87 #include "wav_util.h"
88 #define STORE_TO_WAV_FILE
89 #endif
90 
91 #define NUM_CHANNELS 2
92 #define BYTES_PER_FRAME     (2*NUM_CHANNELS)
93 #define MAX_SBC_FRAME_SIZE 120
94 
95 // SBC Decoder for WAV file or live playback
96 static btstack_sbc_decoder_state_t state;
97 static btstack_sbc_mode_t mode = SBC_MODE_STANDARD;
98 
99 // ring buffer for SBC Frames
100 // below 30: add samples, 30-40: fine, above 40: drop samples
101 #define OPTIMAL_FRAMES_MIN 30
102 #define OPTIMAL_FRAMES_MAX 40
103 #define ADDITIONAL_FRAMES  20
104 static uint8_t sbc_frame_storage[(OPTIMAL_FRAMES_MAX + ADDITIONAL_FRAMES) * MAX_SBC_FRAME_SIZE];
105 static btstack_ring_buffer_t sbc_frame_ring_buffer;
106 static unsigned int sbc_frame_size;
107 
108 // rest buffer for not fully used sbc frames, with additional frames for resampling
109 static uint8_t decoded_audio_storage[(128+16) * BYTES_PER_FRAME];
110 static btstack_ring_buffer_t decoded_audio_ring_buffer;
111 
112 static int audio_stream_started;
113 
114 // temp storage of lower-layer request
115 static int16_t * request_buffer;
116 static int       request_frames;
117 
118 #define STORE_FROM_PLAYBACK
119 
120 // WAV File
121 #ifdef STORE_TO_WAV_FILE
122 static uint32_t audio_frame_count = 0;
123 static char * wav_filename = "a2dp_sink_demo.wav";
124 #endif
125 
126 typedef struct {
127     int reconfigure;
128 
129     int num_channels;
130     int sampling_frequency;
131     int block_length;
132     int subbands;
133     int min_bitpool_value;
134     int max_bitpool_value;
135     btstack_sbc_channel_mode_t      channel_mode;
136     btstack_sbc_allocation_method_t allocation_method;
137 } media_codec_configuration_sbc_t;
138 
139 static media_codec_configuration_sbc_t sbc_configuration;
140 static int volume_percentage = 0;
141 static avrcp_battery_status_t battery_status = AVRCP_BATTERY_STATUS_WARNING;
142 
143 #ifdef HAVE_BTSTACK_STDIN
144 // pts:
145 static const char * device_addr_string = "5C:F3:70:60:7B:87";
146 // mac 2013:  static const char * device_addr_string = "84:38:35:65:d1:15";
147 // iPhone 5S: static const char * device_addr_string = "54:E4:3A:26:A2:39";
148 static bd_addr_t device_addr;
149 #endif
150 
151 static btstack_packet_callback_registration_t hci_event_callback_registration;
152 
153 static uint8_t  sdp_avdtp_sink_service_buffer[150];
154 static uint8_t  sdp_avrcp_target_service_buffer[150];
155 static uint8_t  sdp_avrcp_controller_service_buffer[200];
156 static uint8_t  device_id_sdp_service_buffer[100];
157 
158 static uint16_t a2dp_cid = 0;
159 static uint8_t  a2dp_local_seid = 0;
160 
161 static uint16_t avrcp_cid = 0;
162 static uint8_t  avrcp_connected = 0;
163 static uint8_t  avrcp_subevent_value[255];
164 
165 static uint8_t media_sbc_codec_capabilities[] = {
166     0xFF,//(AVDTP_SBC_44100 << 4) | AVDTP_SBC_STEREO,
167     0xFF,//(AVDTP_SBC_BLOCK_LENGTH_16 << 4) | (AVDTP_SBC_SUBBANDS_8 << 2) | AVDTP_SBC_ALLOCATION_METHOD_LOUDNESS,
168     2, 53
169 };
170 
171 static uint8_t media_sbc_codec_configuration[4];
172 
173 static int media_initialized = 0;
174 static btstack_resample_t resample_instance;
175 
176 /* @section Main Application Setup
177  *
178  * @text The Listing MainConfiguration shows how to setup AD2P Sink and AVRCP services.
179  * Besides calling init() method for each service, you'll also need to register several packet handlers:
180  * - hci_packet_handler - handles legacy pairing, here by using fixed '0000' pin code.
181  * - a2dp_sink_packet_handler - handles events on stream connection status (established, released), the media codec configuration, and, the status of the stream itself (opened, paused, stopped).
182  * - handle_l2cap_media_data_packet - used to receive streaming data. If STORE_TO_WAV_FILE directive (check btstack_config.h) is used, the SBC decoder will be used to decode the SBC data into PCM frames. The resulting PCM frames are then processed in the SBC Decoder callback.
183  * - avrcp_packet_handler - receives connect/disconnect event.
184  * - avrcp_controller_packet_handler - receives answers for sent AVRCP commands.
185  * - avrcp_target_packet_handler - receives AVRCP commands, and registered notifications.
186  * - 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.
187  *
188  * @text To announce A2DP Sink and AVRCP services, you need to create corresponding
189  * SDP records and register them with the SDP service.
190  *
191  * @text Note, currently only the SBC codec is supported.
192  * If you want to store the audio data in a file, you'll need to define STORE_TO_WAV_FILE.
193  * If STORE_TO_WAV_FILE directive is defined, the SBC decoder needs to get initialized when a2dp_sink_packet_handler receives event A2DP_SUBEVENT_STREAM_STARTED.
194  * The initialization of the SBC decoder requires a callback that handles PCM data:
195  * - handle_pcm_data - handles PCM audio frames. Here, they are stored a in wav file if STORE_TO_WAV_FILE is defined, and/or played using the audio library.
196  */
197 
198 /* LISTING_START(MainConfiguration): Setup Audio Sink and AVRCP services */
199 static void hci_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
200 static void a2dp_sink_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t * event, uint16_t event_size);
201 static void handle_l2cap_media_data_packet(uint8_t seid, uint8_t *packet, uint16_t size);
202 static void avrcp_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
203 static void avrcp_controller_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
204 static void avrcp_target_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
205 #ifdef HAVE_BTSTACK_STDIN
206 static void stdin_process(char cmd);
207 #endif
208 
209 static int a2dp_and_avrcp_setup(void){
210 
211     l2cap_init();
212 
213 #ifdef ENABLE_BLE
214     // Initialize LE Security Manager. Needed for cross-transport key derivation
215     sm_init();
216 #endif
217 
218     // Initialize AVDTP Sink
219     a2dp_sink_init();
220     a2dp_sink_register_packet_handler(&a2dp_sink_packet_handler);
221     a2dp_sink_register_media_handler(&handle_l2cap_media_data_packet);
222 
223     // Create stream endpoint
224     avdtp_stream_endpoint_t * local_stream_endpoint = a2dp_sink_create_stream_endpoint(AVDTP_AUDIO,
225         AVDTP_CODEC_SBC, media_sbc_codec_capabilities, sizeof(media_sbc_codec_capabilities),
226         media_sbc_codec_configuration, sizeof(media_sbc_codec_configuration));
227     if (!local_stream_endpoint){
228         printf("A2DP Sink: not enough memory to create local stream endpoint\n");
229         return 1;
230     }
231 
232     // Store stream enpoint's SEP ID, as it is used by A2DP API to indentify the stream endpoint
233     a2dp_local_seid = avdtp_local_seid(local_stream_endpoint);
234 
235     // Initialize AVRCP service
236     avrcp_init();
237     avrcp_register_packet_handler(&avrcp_packet_handler);
238 
239     // Initialize AVRCP Controller
240     avrcp_controller_init();
241     avrcp_controller_register_packet_handler(&avrcp_controller_packet_handler);
242 
243      // Initialize AVRCP Target
244     avrcp_target_init();
245     avrcp_target_register_packet_handler(&avrcp_target_packet_handler);
246 
247     // Initialize SDP
248     sdp_init();
249 
250     // Create A2DP Sink service record and register it with SDP
251     memset(sdp_avdtp_sink_service_buffer, 0, sizeof(sdp_avdtp_sink_service_buffer));
252     a2dp_sink_create_sdp_record(sdp_avdtp_sink_service_buffer, 0x10001, AVDTP_SINK_FEATURE_MASK_HEADPHONE, NULL, NULL);
253     sdp_register_service(sdp_avdtp_sink_service_buffer);
254 
255     // Create AVRCP Controller service record and register it with SDP. We send Category 1 commands to the media player, e.g. play/pause
256     memset(sdp_avrcp_controller_service_buffer, 0, sizeof(sdp_avrcp_controller_service_buffer));
257     uint16_t controller_supported_features = AVRCP_FEATURE_MASK_CATEGORY_PLAYER_OR_RECORDER;
258 #ifdef AVRCP_BROWSING_ENABLED
259     controller_supported_features |= AVRCP_FEATURE_MASK_BROWSING;
260 #endif
261     avrcp_controller_create_sdp_record(sdp_avrcp_controller_service_buffer, 0x10002, controller_supported_features, NULL, NULL);
262     sdp_register_service(sdp_avrcp_controller_service_buffer);
263 
264     // Create AVRCP Target service record and register it with SDP. We receive Category 2 commands from the media player, e.g. volume up/down
265     memset(sdp_avrcp_target_service_buffer, 0, sizeof(sdp_avrcp_target_service_buffer));
266     uint16_t target_supported_features = AVRCP_FEATURE_MASK_CATEGORY_MONITOR_OR_AMPLIFIER;
267     avrcp_target_create_sdp_record(sdp_avrcp_target_service_buffer, 0x10003, target_supported_features, NULL, NULL);
268     sdp_register_service(sdp_avrcp_target_service_buffer);
269 
270     // Create Device ID (PnP) service record and register it with SDP
271     memset(device_id_sdp_service_buffer, 0, sizeof(device_id_sdp_service_buffer));
272     device_id_create_sdp_record(device_id_sdp_service_buffer, 0x10004, DEVICE_ID_VENDOR_ID_SOURCE_BLUETOOTH, BLUETOOTH_COMPANY_ID_BLUEKITCHEN_GMBH, 1, 1);
273     sdp_register_service(device_id_sdp_service_buffer);
274 
275     // Set local name with a template Bluetooth address, that will be automatically
276     // replaced with a actual address once it is available, i.e. when BTstack boots
277     // up and starts talking to a Bluetooth module.
278     gap_set_local_name("A2DP Sink Demo 00:00:00:00:00:00");
279 
280     // allot to show up in Bluetooth inquiry
281     gap_discoverable_control(1);
282 
283     // Service Class: Audio, Major Device Class: Audio, Minor: Loudspeaker
284     gap_set_class_of_device(0x200414);
285 
286     // allow for role switch in general and sniff mode
287     gap_set_default_link_policy_settings( LM_LINK_POLICY_ENABLE_ROLE_SWITCH | LM_LINK_POLICY_ENABLE_SNIFF_MODE );
288 
289     // allow for role switch on outgoing connections - this allows A2DP Source, e.g. smartphone, to become master when we re-connect to it
290     gap_set_allow_role_switch(true);
291 
292     // Register for HCI events
293     hci_event_callback_registration.callback = &hci_packet_handler;
294     hci_add_event_handler(&hci_event_callback_registration);
295 
296 #ifdef HAVE_POSIX_FILE_IO
297     if (!btstack_audio_sink_get_instance()){
298         printf("No audio playback.\n");
299     } else {
300         printf("Audio playback supported.\n");
301     }
302 #ifdef STORE_TO_WAV_FILE
303    printf("Audio will be stored to \'%s\' file.\n",  wav_filename);
304 #endif
305 #endif
306     return 0;
307 }
308 /* LISTING_END */
309 
310 static void playback_handler(int16_t * buffer, uint16_t num_audio_frames){
311 
312 #ifdef STORE_TO_WAV_FILE
313     int       wav_samples = num_audio_frames * NUM_CHANNELS;
314     int16_t * wav_buffer  = buffer;
315 #endif
316 
317     // called from lower-layer but guaranteed to be on main thread
318     if (sbc_frame_size == 0){
319         memset(buffer, 0, num_audio_frames * BYTES_PER_FRAME);
320         return;
321     }
322 
323     // first fill from resampled audio
324     uint32_t bytes_read;
325     btstack_ring_buffer_read(&decoded_audio_ring_buffer, (uint8_t *) buffer, num_audio_frames * BYTES_PER_FRAME, &bytes_read);
326     buffer          += bytes_read / NUM_CHANNELS;
327     num_audio_frames   -= bytes_read / BYTES_PER_FRAME;
328 
329     // then start decoding sbc frames using request_* globals
330     request_buffer = buffer;
331     request_frames = num_audio_frames;
332     while (request_frames && btstack_ring_buffer_bytes_available(&sbc_frame_ring_buffer) >= sbc_frame_size){
333         // decode frame
334         uint8_t sbc_frame[MAX_SBC_FRAME_SIZE];
335         btstack_ring_buffer_read(&sbc_frame_ring_buffer, sbc_frame, sbc_frame_size, &bytes_read);
336         btstack_sbc_decoder_process_data(&state, 0, sbc_frame, sbc_frame_size);
337     }
338 
339 #ifdef STORE_TO_WAV_FILE
340     audio_frame_count += num_audio_frames;
341     wav_writer_write_int16(wav_samples, wav_buffer);
342 #endif
343 }
344 
345 static void handle_pcm_data(int16_t * data, int num_audio_frames, int num_channels, int sample_rate, void * context){
346     UNUSED(sample_rate);
347     UNUSED(context);
348     UNUSED(num_channels);   // must be stereo == 2
349 
350     const btstack_audio_sink_t * audio_sink = btstack_audio_sink_get_instance();
351     if (!audio_sink){
352 #ifdef STORE_TO_WAV_FILE
353         audio_frame_count += num_audio_frames;
354         wav_writer_write_int16(num_audio_frames * NUM_CHANNELS, data);
355 #endif
356         return;
357     }
358 
359     // resample into request buffer - add some additional space for resampling
360     int16_t  output_buffer[(128+16) * NUM_CHANNELS]; // 16 * 8 * 2
361     uint32_t resampled_frames = btstack_resample_block(&resample_instance, data, num_audio_frames, output_buffer);
362 
363     // store data in btstack_audio buffer first
364     int frames_to_copy = btstack_min(resampled_frames, request_frames);
365     memcpy(request_buffer, output_buffer, frames_to_copy * BYTES_PER_FRAME);
366     request_frames  -= frames_to_copy;
367     request_buffer  += frames_to_copy * NUM_CHANNELS;
368 
369     // and rest in ring buffer
370     int frames_to_store = resampled_frames - frames_to_copy;
371     if (frames_to_store){
372         int status = btstack_ring_buffer_write(&decoded_audio_ring_buffer, (uint8_t *)&output_buffer[frames_to_copy * NUM_CHANNELS], frames_to_store * BYTES_PER_FRAME);
373         if (status){
374             printf("Error storing samples in PCM ring buffer!!!\n");
375         }
376     }
377 }
378 
379 static int media_processing_init(media_codec_configuration_sbc_t configuration){
380     if (media_initialized) return 0;
381 
382     btstack_sbc_decoder_init(&state, mode, handle_pcm_data, NULL);
383 
384 #ifdef STORE_TO_WAV_FILE
385     wav_writer_open(wav_filename, configuration.num_channels, configuration.sampling_frequency);
386 #endif
387 
388     btstack_ring_buffer_init(&sbc_frame_ring_buffer, sbc_frame_storage, sizeof(sbc_frame_storage));
389     btstack_ring_buffer_init(&decoded_audio_ring_buffer, decoded_audio_storage, sizeof(decoded_audio_storage));
390     btstack_resample_init(&resample_instance, configuration.num_channels);
391 
392     // setup audio playback
393     const btstack_audio_sink_t * audio = btstack_audio_sink_get_instance();
394     if (audio){
395         audio->init(NUM_CHANNELS, configuration.sampling_frequency, &playback_handler);
396     }
397 
398     audio_stream_started = 0;
399     media_initialized = 1;
400     return 0;
401 }
402 
403 static void media_processing_start(void){
404     if (!media_initialized) return;
405     // setup audio playback
406     const btstack_audio_sink_t * audio = btstack_audio_sink_get_instance();
407     if (audio){
408         audio->start_stream();
409     }
410     audio_stream_started = 1;
411 }
412 
413 static void media_processing_pause(void){
414     if (!media_initialized) return;
415     // stop audio playback
416     audio_stream_started = 0;
417     const btstack_audio_sink_t * audio = btstack_audio_sink_get_instance();
418     if (audio){
419         audio->stop_stream();
420     }
421 }
422 
423 static void media_processing_close(void){
424     if (!media_initialized) return;
425     media_initialized = 0;
426     audio_stream_started = 0;
427     sbc_frame_size = 0;
428 
429 #ifdef STORE_TO_WAV_FILE
430     wav_writer_close();
431     uint32_t total_frames_nr = state.good_frames_nr + state.bad_frames_nr + state.zero_frames_nr;
432 
433     printf("WAV Writer: Decoding done. Processed %u SBC frames:\n - %d good\n - %d bad\n", total_frames_nr, state.good_frames_nr, total_frames_nr - state.good_frames_nr);
434     printf("WAV Writer: Wrote %u audio frames to wav file: %s\n", audio_frame_count, wav_filename);
435 #endif
436 
437     // stop audio playback
438     const btstack_audio_sink_t * audio = btstack_audio_sink_get_instance();
439     if (audio){
440         printf("close stream\n");
441         audio->close();
442     }
443 }
444 
445 /* @section Handle Media Data Packet
446  *
447  * @text Here the audio data, are received through the handle_l2cap_media_data_packet callback.
448  * Currently, only the SBC media codec is supported. Hence, the media data consists of the media packet header and the SBC packet.
449  * The SBC frame will be stored in a ring buffer for later processing (instead of decoding it to PCM right away which would require a much larger buffer).
450  * If the audio stream wasn't started already and there are enough SBC frames in the ring buffer, start playback.
451  */
452 
453 static int read_media_data_header(uint8_t * packet, int size, int * offset, avdtp_media_packet_header_t * media_header);
454 static int read_sbc_header(uint8_t * packet, int size, int * offset, avdtp_sbc_codec_header_t * sbc_header);
455 
456 static void handle_l2cap_media_data_packet(uint8_t seid, uint8_t *packet, uint16_t size){
457     UNUSED(seid);
458     int pos = 0;
459 
460     avdtp_media_packet_header_t media_header;
461     if (!read_media_data_header(packet, size, &pos, &media_header)) return;
462 
463     avdtp_sbc_codec_header_t sbc_header;
464     if (!read_sbc_header(packet, size, &pos, &sbc_header)) return;
465 
466     const btstack_audio_sink_t * audio = btstack_audio_sink_get_instance();
467     // process data right away if there's no audio implementation active, e.g. on posix systems to store as .wav
468     if (!audio){
469         btstack_sbc_decoder_process_data(&state, 0, packet+pos, size-pos);
470         return;
471     }
472 
473     // store sbc frame size for buffer management
474     sbc_frame_size = (size-pos)/ sbc_header.num_frames;
475 
476     int status = btstack_ring_buffer_write(&sbc_frame_ring_buffer, packet+pos, size-pos);
477     if (status != ERROR_CODE_SUCCESS){
478         printf("Error storing samples in SBC ring buffer!!!\n");
479     }
480 
481     // decide on audio sync drift based on number of sbc frames in queue
482     int sbc_frames_in_buffer = btstack_ring_buffer_bytes_available(&sbc_frame_ring_buffer) / sbc_frame_size;
483     uint32_t resampling_factor;
484 
485     // nomimal factor (fixed-point 2^16) and compensation offset
486     uint32_t nomimal_factor = 0x10000;
487     uint32_t compensation   = 0x00100;
488 
489     if (sbc_frames_in_buffer < OPTIMAL_FRAMES_MIN){
490     	resampling_factor = nomimal_factor - compensation;    // stretch samples
491     } else if (sbc_frames_in_buffer <= OPTIMAL_FRAMES_MAX){
492     	resampling_factor = nomimal_factor;                   // nothing to do
493     } else {
494     	resampling_factor = nomimal_factor + compensation;    // compress samples
495     }
496 
497     btstack_resample_set_factor(&resample_instance, resampling_factor);
498 
499     // start stream if enough frames buffered
500     if (!audio_stream_started && sbc_frames_in_buffer >= OPTIMAL_FRAMES_MIN){
501         media_processing_start();
502     }
503 }
504 
505 static int read_sbc_header(uint8_t * packet, int size, int * offset, avdtp_sbc_codec_header_t * sbc_header){
506     int sbc_header_len = 12; // without crc
507     int pos = *offset;
508 
509     if (size - pos < sbc_header_len){
510         printf("Not enough data to read SBC header, expected %d, received %d\n", sbc_header_len, size-pos);
511         return 0;
512     }
513 
514     sbc_header->fragmentation = get_bit16(packet[pos], 7);
515     sbc_header->starting_packet = get_bit16(packet[pos], 6);
516     sbc_header->last_packet = get_bit16(packet[pos], 5);
517     sbc_header->num_frames = packet[pos] & 0x0f;
518     pos++;
519     *offset = pos;
520     return 1;
521 }
522 
523 static int read_media_data_header(uint8_t *packet, int size, int *offset, avdtp_media_packet_header_t *media_header){
524     int media_header_len = 12; // without crc
525     int pos = *offset;
526 
527     if (size - pos < media_header_len){
528         printf("Not enough data to read media packet header, expected %d, received %d\n", media_header_len, size-pos);
529         return 0;
530     }
531 
532     media_header->version = packet[pos] & 0x03;
533     media_header->padding = get_bit16(packet[pos],2);
534     media_header->extension = get_bit16(packet[pos],3);
535     media_header->csrc_count = (packet[pos] >> 4) & 0x0F;
536     pos++;
537 
538     media_header->marker = get_bit16(packet[pos],0);
539     media_header->payload_type  = (packet[pos] >> 1) & 0x7F;
540     pos++;
541 
542     media_header->sequence_number = big_endian_read_16(packet, pos);
543     pos+=2;
544 
545     media_header->timestamp = big_endian_read_32(packet, pos);
546     pos+=4;
547 
548     media_header->synchronization_source = big_endian_read_32(packet, pos);
549     pos+=4;
550     *offset = pos;
551     return 1;
552 }
553 
554 static void dump_sbc_configuration(media_codec_configuration_sbc_t configuration){
555     printf("    - num_channels: %d\n", configuration.num_channels);
556     printf("    - sampling_frequency: %d\n", configuration.sampling_frequency);
557     printf("    - channel_mode: %d\n", configuration.channel_mode);
558     printf("    - block_length: %d\n", configuration.block_length);
559     printf("    - subbands: %d\n", configuration.subbands);
560     printf("    - allocation_method: %d\n", configuration.allocation_method);
561     printf("    - bitpool_value [%d, %d] \n", configuration.min_bitpool_value, configuration.max_bitpool_value);
562     printf("\n");
563 }
564 
565 static void avrcp_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
566     UNUSED(channel);
567     UNUSED(size);
568     uint16_t local_cid;
569     uint8_t  status;
570     bd_addr_t address;
571 
572     if (packet_type != HCI_EVENT_PACKET) return;
573     if (hci_event_packet_get_type(packet) != HCI_EVENT_AVRCP_META) return;
574     switch (packet[2]){
575         case AVRCP_SUBEVENT_CONNECTION_ESTABLISHED: {
576             local_cid = avrcp_subevent_connection_established_get_avrcp_cid(packet);
577             status = avrcp_subevent_connection_established_get_status(packet);
578             if (status != ERROR_CODE_SUCCESS){
579                 printf("AVRCP: Connection failed: status 0x%02x\n", status);
580                 avrcp_cid = 0;
581                 return;
582             }
583 
584             avrcp_cid = local_cid;
585             avrcp_connected = 1;
586             avrcp_subevent_connection_established_get_bd_addr(packet, address);
587             printf("AVRCP: Connected to %s, cid 0x%02x\n", bd_addr_to_str(address), avrcp_cid);
588 
589             avrcp_target_support_event(avrcp_cid, AVRCP_NOTIFICATION_EVENT_VOLUME_CHANGED);
590             avrcp_target_support_event(avrcp_cid, AVRCP_NOTIFICATION_EVENT_BATT_STATUS_CHANGED);
591             avrcp_target_battery_status_changed(avrcp_cid, battery_status);
592 
593             // automatically enable notifications
594             avrcp_controller_enable_notification(avrcp_cid, AVRCP_NOTIFICATION_EVENT_PLAYBACK_STATUS_CHANGED);
595             avrcp_controller_enable_notification(avrcp_cid, AVRCP_NOTIFICATION_EVENT_NOW_PLAYING_CONTENT_CHANGED);
596             avrcp_controller_enable_notification(avrcp_cid, AVRCP_NOTIFICATION_EVENT_TRACK_CHANGED);
597             return;
598         }
599 
600         case AVRCP_SUBEVENT_CONNECTION_RELEASED:
601             printf("AVRCP: Channel released: cid 0x%02x\n", avrcp_subevent_connection_released_get_avrcp_cid(packet));
602             avrcp_cid = 0;
603             avrcp_connected = 0;
604             return;
605         default:
606             break;
607     }
608 }
609 
610 static void avrcp_controller_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
611     UNUSED(channel);
612     UNUSED(size);
613 
614     if (packet_type != HCI_EVENT_PACKET) return;
615     if (hci_event_packet_get_type(packet) != HCI_EVENT_AVRCP_META) return;
616     if (!avrcp_cid) return;
617 
618     memset(avrcp_subevent_value, 0, sizeof(avrcp_subevent_value));
619     switch (packet[2]){
620         case AVRCP_SUBEVENT_NOTIFICATION_PLAYBACK_POS_CHANGED:
621             printf("AVRCP Controller: Playback position changed, position %d ms\n", (unsigned int) avrcp_subevent_notification_playback_pos_changed_get_playback_position_ms(packet));
622             break;
623         case AVRCP_SUBEVENT_NOTIFICATION_PLAYBACK_STATUS_CHANGED:
624             printf("AVRCP Controller: Playback status changed %s\n", avrcp_play_status2str(avrcp_subevent_notification_playback_status_changed_get_play_status(packet)));
625             return;
626         case AVRCP_SUBEVENT_NOTIFICATION_NOW_PLAYING_CONTENT_CHANGED:
627             printf("AVRCP Controller: Playing content changed\n");
628             return;
629         case AVRCP_SUBEVENT_NOTIFICATION_TRACK_CHANGED:
630             printf("AVRCP Controller: Track changed\n");
631             return;
632         case AVRCP_SUBEVENT_NOTIFICATION_AVAILABLE_PLAYERS_CHANGED:
633             printf("AVRCP Controller: Changed\n");
634             return;
635         case AVRCP_SUBEVENT_SHUFFLE_AND_REPEAT_MODE:{
636             uint8_t shuffle_mode = avrcp_subevent_shuffle_and_repeat_mode_get_shuffle_mode(packet);
637             uint8_t repeat_mode  = avrcp_subevent_shuffle_and_repeat_mode_get_repeat_mode(packet);
638             printf("AVRCP Controller: %s, %s\n", avrcp_shuffle2str(shuffle_mode), avrcp_repeat2str(repeat_mode));
639             break;
640         }
641         case AVRCP_SUBEVENT_NOW_PLAYING_TRACK_INFO:
642             printf("AVRCP Controller:     Track: %d\n", avrcp_subevent_now_playing_track_info_get_track(packet));
643             break;
644 
645         case AVRCP_SUBEVENT_NOW_PLAYING_TOTAL_TRACKS_INFO:
646             printf("AVRCP Controller:     Total Tracks: %d\n", avrcp_subevent_now_playing_total_tracks_info_get_total_tracks(packet));
647             break;
648 
649         case AVRCP_SUBEVENT_NOW_PLAYING_TITLE_INFO:
650             if (avrcp_subevent_now_playing_title_info_get_value_len(packet) > 0){
651                 memcpy(avrcp_subevent_value, avrcp_subevent_now_playing_title_info_get_value(packet), avrcp_subevent_now_playing_title_info_get_value_len(packet));
652                 printf("AVRCP Controller:     Title: %s\n", avrcp_subevent_value);
653             }
654             break;
655 
656         case AVRCP_SUBEVENT_NOW_PLAYING_ARTIST_INFO:
657             if (avrcp_subevent_now_playing_artist_info_get_value_len(packet) > 0){
658                 memcpy(avrcp_subevent_value, avrcp_subevent_now_playing_artist_info_get_value(packet), avrcp_subevent_now_playing_artist_info_get_value_len(packet));
659                 printf("AVRCP Controller:     Artist: %s\n", avrcp_subevent_value);
660             }
661             break;
662 
663         case AVRCP_SUBEVENT_NOW_PLAYING_ALBUM_INFO:
664             if (avrcp_subevent_now_playing_album_info_get_value_len(packet) > 0){
665                 memcpy(avrcp_subevent_value, avrcp_subevent_now_playing_album_info_get_value(packet), avrcp_subevent_now_playing_album_info_get_value_len(packet));
666                 printf("AVRCP Controller:     Album: %s\n", avrcp_subevent_value);
667             }
668             break;
669 
670         case AVRCP_SUBEVENT_NOW_PLAYING_GENRE_INFO:
671             if (avrcp_subevent_now_playing_genre_info_get_value_len(packet) > 0){
672                 memcpy(avrcp_subevent_value, avrcp_subevent_now_playing_genre_info_get_value(packet), avrcp_subevent_now_playing_genre_info_get_value_len(packet));
673                 printf("AVRCP Controller:     Genre: %s\n", avrcp_subevent_value);
674             }
675             break;
676 
677         case AVRCP_SUBEVENT_PLAY_STATUS:
678             printf("AVRCP Controller: Song length %"PRIu32" ms, Song position %"PRIu32" ms, Play status %s\n",
679                 avrcp_subevent_play_status_get_song_length(packet),
680                 avrcp_subevent_play_status_get_song_position(packet),
681                 avrcp_play_status2str(avrcp_subevent_play_status_get_play_status(packet)));
682             break;
683 
684         case AVRCP_SUBEVENT_OPERATION_COMPLETE:
685             printf("AVRCP Controller: %s complete\n", avrcp_operation2str(avrcp_subevent_operation_complete_get_operation_id(packet)));
686             break;
687 
688         case AVRCP_SUBEVENT_OPERATION_START:
689             printf("AVRCP Controller: %s start\n", avrcp_operation2str(avrcp_subevent_operation_start_get_operation_id(packet)));
690             break;
691 
692         case AVRCP_SUBEVENT_NOTIFICATION_EVENT_TRACK_REACHED_END:
693             printf("AVRCP Controller: Track reached end\n");
694             break;
695 
696         case AVRCP_SUBEVENT_PLAYER_APPLICATION_VALUE_RESPONSE:
697             printf("AVRCP Controller: Set Player App Value %s\n", avrcp_ctype2str(avrcp_subevent_player_application_value_response_get_command_type(packet)));
698             break;
699 
700         default:
701             break;
702     }
703 }
704 
705 static void avrcp_volume_changed(uint8_t volume){
706     const btstack_audio_sink_t * audio = btstack_audio_sink_get_instance();
707     if (audio){
708         audio->set_volume(volume);
709     }
710 }
711 
712 static void avrcp_target_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
713     UNUSED(channel);
714     UNUSED(size);
715 
716     if (packet_type != HCI_EVENT_PACKET) return;
717     if (hci_event_packet_get_type(packet) != HCI_EVENT_AVRCP_META) return;
718 
719     uint8_t volume;
720     char const * button_state;
721     avrcp_operation_id_t operation_id;
722 
723     switch (packet[2]){
724         case AVRCP_SUBEVENT_NOTIFICATION_VOLUME_CHANGED:
725             volume = avrcp_subevent_notification_volume_changed_get_absolute_volume(packet);
726             volume_percentage = volume * 100 / 127;
727             printf("AVRCP Target    : Volume set to %d%% (%d)\n", volume_percentage, volume);
728             avrcp_volume_changed(volume);
729             break;
730 
731         case AVRCP_SUBEVENT_OPERATION:
732             operation_id = avrcp_subevent_operation_get_operation_id(packet);
733             button_state = avrcp_subevent_operation_get_button_pressed(packet) > 0 ? "PRESS" : "RELEASE";
734             switch (operation_id){
735                 case AVRCP_OPERATION_ID_VOLUME_UP:
736                     printf("AVRCP Target    : VOLUME UP (%s)\n", button_state);
737                     break;
738                 case AVRCP_OPERATION_ID_VOLUME_DOWN:
739                     printf("AVRCP Target    : VOLUME UP (%s)\n", button_state);
740                     break;
741                 default:
742                     return;
743             }
744             break;
745         default:
746             printf("AVRCP Target    : Event 0x%02x is not parsed\n", packet[2]);
747             break;
748     }
749 }
750 
751 static void hci_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
752     UNUSED(channel);
753     UNUSED(size);
754     if (packet_type != HCI_EVENT_PACKET) return;
755     if (hci_event_packet_get_type(packet) == HCI_EVENT_PIN_CODE_REQUEST) {
756         bd_addr_t address;
757         printf("Pin code request - using '0000'\n");
758         hci_event_pin_code_request_get_bd_addr(packet, address);
759         gap_pin_code_response(address, "0000");
760     }
761 }
762 
763 static void a2dp_sink_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
764     UNUSED(channel);
765     UNUSED(size);
766     bd_addr_t address;
767     uint8_t status;
768 
769     uint8_t allocation_method;
770 
771     if (packet_type != HCI_EVENT_PACKET) return;
772     if (hci_event_packet_get_type(packet) != HCI_EVENT_A2DP_META) return;
773 
774     switch (packet[2]){
775         case A2DP_SUBEVENT_SIGNALING_MEDIA_CODEC_OTHER_CONFIGURATION:
776             printf("A2DP  Sink      : Received non SBC codec - not implemented\n");
777             break;
778         case A2DP_SUBEVENT_SIGNALING_MEDIA_CODEC_SBC_CONFIGURATION:{
779             printf("A2DP  Sink      : Received SBC codec configuration\n");
780             sbc_configuration.reconfigure = a2dp_subevent_signaling_media_codec_sbc_configuration_get_reconfigure(packet);
781             sbc_configuration.num_channels = a2dp_subevent_signaling_media_codec_sbc_configuration_get_num_channels(packet);
782             sbc_configuration.sampling_frequency = a2dp_subevent_signaling_media_codec_sbc_configuration_get_sampling_frequency(packet);
783             sbc_configuration.block_length = a2dp_subevent_signaling_media_codec_sbc_configuration_get_block_length(packet);
784             sbc_configuration.subbands = a2dp_subevent_signaling_media_codec_sbc_configuration_get_subbands(packet);
785             sbc_configuration.min_bitpool_value = a2dp_subevent_signaling_media_codec_sbc_configuration_get_min_bitpool_value(packet);
786             sbc_configuration.max_bitpool_value = a2dp_subevent_signaling_media_codec_sbc_configuration_get_max_bitpool_value(packet);
787 
788             allocation_method = a2dp_subevent_signaling_media_codec_sbc_configuration_get_allocation_method(packet);
789 
790             // Adapt Bluetooth spec definition to SBC Encoder expected input
791             sbc_configuration.allocation_method = (btstack_sbc_allocation_method_t)(allocation_method - 1);
792 
793             switch (a2dp_subevent_signaling_media_codec_sbc_configuration_get_channel_mode(packet)){
794                 case AVDTP_CHANNEL_MODE_JOINT_STEREO:
795                     sbc_configuration.channel_mode = SBC_CHANNEL_MODE_JOINT_STEREO;
796                     break;
797                 case AVDTP_CHANNEL_MODE_STEREO:
798                     sbc_configuration.channel_mode = SBC_CHANNEL_MODE_STEREO;
799                     break;
800                 case AVDTP_CHANNEL_MODE_DUAL_CHANNEL:
801                     sbc_configuration.channel_mode = SBC_CHANNEL_MODE_DUAL_CHANNEL;
802                     break;
803                 case AVDTP_CHANNEL_MODE_MONO:
804                     sbc_configuration.channel_mode = SBC_CHANNEL_MODE_MONO;
805                     break;
806                 default:
807                     btstack_assert(false);
808                     break;
809             }
810             dump_sbc_configuration(sbc_configuration);
811 
812             if (sbc_configuration.reconfigure){
813                 media_processing_close();
814             }
815             // prepare media processing
816             media_processing_init(sbc_configuration);
817             break;
818         }
819         case A2DP_SUBEVENT_STREAM_ESTABLISHED:
820             a2dp_subevent_stream_established_get_bd_addr(packet, address);
821             status = a2dp_subevent_stream_established_get_status(packet);
822             if (status != ERROR_CODE_SUCCESS){
823                 printf("A2DP  Sink      : Streaming connection failed, status 0x%02x\n", status);
824                 break;
825             }
826 
827             a2dp_cid = a2dp_subevent_stream_established_get_a2dp_cid(packet);
828             printf("A2DP  Sink      : Streaming connection is established, address %s, cid 0x%02X, local seid %d\n", bd_addr_to_str(address), a2dp_cid, a2dp_local_seid);
829 #ifdef HAVE_BTSTACK_STDIN
830             // use address for outgoing connections
831             memcpy(device_addr, address, 6);
832 #endif
833             break;
834 
835 #ifdef ENABLE_AVDTP_ACCEPTOR_EXPLICIT_START_STREAM_CONFIRMATION
836         case A2DP_SUBEVENT_START_STREAM_REQUESTED:
837             printf("A2DP  Sink      : Explicit Accept to start stream, local_seid 0x%02x\n", a2dp_subevent_start_stream_requested_get_local_seid(packet));
838             a2dp_sink_start_stream_accept(a2dp_cid, a2dp_local_seid);
839             break;
840 #endif
841         case A2DP_SUBEVENT_STREAM_STARTED:
842             printf("A2DP  Sink      : Stream started\n");
843             // audio stream is started when buffer reaches minimal level
844             break;
845 
846         case A2DP_SUBEVENT_STREAM_SUSPENDED:
847             printf("A2DP  Sink      : Stream paused\n");
848             media_processing_pause();
849             break;
850 
851         case A2DP_SUBEVENT_STREAM_RELEASED:
852             printf("A2DP  Sink      : Stream released\n");
853             media_processing_close();
854             break;
855 
856         case A2DP_SUBEVENT_SIGNALING_CONNECTION_RELEASED:
857             printf("A2DP  Sink      : Signaling connection released\n");
858             media_processing_close();
859             break;
860 
861         default:
862             break;
863     }
864 }
865 
866 #ifdef HAVE_BTSTACK_STDIN
867 static void show_usage(void){
868     bd_addr_t      iut_address;
869     gap_local_bd_addr(iut_address);
870     printf("\n--- Bluetooth AVDTP Sink/AVRCP Connection Test Console %s ---\n", bd_addr_to_str(iut_address));
871     printf("b      - AVDTP Sink create  connection to addr %s\n", bd_addr_to_str(device_addr));
872     printf("B      - AVDTP Sink disconnect\n");
873     printf("c      - AVRCP create connection to addr %s\n", bd_addr_to_str(device_addr));
874     printf("C      - AVRCP disconnect\n");
875 
876     printf("w - delay report\n");
877 
878     printf("\n--- Bluetooth AVRCP Commands %s ---\n", bd_addr_to_str(iut_address));
879     printf("O - get play status\n");
880     printf("j - get now playing info\n");
881     printf("k - play\n");
882     printf("K - stop\n");
883     printf("L - pause\n");
884     printf("u - start fast forward\n");
885     printf("U - stop  fast forward\n");
886     printf("n - start rewind\n");
887     printf("N - stop rewind\n");
888     printf("i - forward\n");
889     printf("I - backward\n");
890     printf("M - mute\n");
891     printf("r - skip\n");
892     printf("q - query repeat and shuffle mode\n");
893     printf("v - repeat single track\n");
894     printf("x - repeat all tracks\n");
895     printf("X - disable repeat mode\n");
896     printf("z - shuffle all tracks\n");
897     printf("Z - disable shuffle mode\n");
898 
899     printf("a/A - register/deregister TRACK_CHANGED\n");
900     printf("R/P - register/deregister PLAYBACK_POS_CHANGED\n");
901 
902     printf("s/S - send/release long button press REWIND\n");
903 
904     printf("\n--- Volume and Battery Control ---\n");
905     printf("t - volume up   for 10 percent\n");
906     printf("T - volume down for 10 percent\n");
907     printf("V - toggle Battery status from AVRCP_BATTERY_STATUS_NORMAL to AVRCP_BATTERY_STATUS_FULL_CHARGE\n");
908     printf("---\n");
909 }
910 #endif
911 
912 #ifdef HAVE_BTSTACK_STDIN
913 static void stdin_process(char cmd){
914     uint8_t status = ERROR_CODE_SUCCESS;
915     uint8_t volume;
916     avrcp_battery_status_t old_battery_status;
917 
918     switch (cmd){
919         case 'b':
920             status = a2dp_sink_establish_stream(device_addr, a2dp_local_seid, &a2dp_cid);
921             printf(" - Create AVDTP connection to addr %s, and local seid %d, expected cid 0x%02x.\n", bd_addr_to_str(device_addr), a2dp_local_seid, a2dp_cid);
922             break;
923         case 'B':
924             printf(" - AVDTP disconnect from addr %s.\n", bd_addr_to_str(device_addr));
925             a2dp_sink_disconnect(a2dp_cid);
926             break;
927         case 'c':
928             printf(" - Create AVRCP connection to addr %s.\n", bd_addr_to_str(device_addr));
929             status = avrcp_connect(device_addr, &avrcp_cid);
930             break;
931         case 'C':
932             printf(" - AVRCP disconnect from addr %s.\n", bd_addr_to_str(device_addr));
933             status = avrcp_disconnect(avrcp_cid);
934             break;
935 
936         case '\n':
937         case '\r':
938             break;
939         case 'w':
940             printf("Send delay report\n");
941             avdtp_sink_delay_report(a2dp_cid, a2dp_local_seid, 100);
942             break;
943         // Volume Control
944         case 't':
945             volume_percentage = volume_percentage <= 90 ? volume_percentage + 10 : 100;
946             volume = volume_percentage * 127 / 100;
947             printf(" - volume up   for 10 percent, %d%% (%d) \n", volume_percentage, volume);
948             status = avrcp_target_volume_changed(avrcp_cid, volume);
949             avrcp_volume_changed(volume);
950             break;
951         case 'T':
952             volume_percentage = volume_percentage >= 10 ? volume_percentage - 10 : 0;
953             volume = volume_percentage * 127 / 100;
954             printf(" - volume down for 10 percent, %d%% (%d) \n", volume_percentage, volume);
955             status = avrcp_target_volume_changed(avrcp_cid, volume);
956             avrcp_volume_changed(volume);
957             break;
958         case 'V':
959             old_battery_status = battery_status;
960 
961             if (battery_status < AVRCP_BATTERY_STATUS_FULL_CHARGE){
962                 battery_status = (avrcp_battery_status_t)((uint8_t) battery_status + 1);
963             } else {
964                 battery_status = AVRCP_BATTERY_STATUS_NORMAL;
965             }
966             printf(" - toggle battery value, old %d, new %d\n", old_battery_status, battery_status);
967             status = avrcp_target_battery_status_changed(avrcp_cid, battery_status);
968             break;
969         case 'O':
970             printf(" - get play status\n");
971             status = avrcp_controller_get_play_status(avrcp_cid);
972             break;
973         case 'j':
974             printf(" - get now playing info\n");
975             status = avrcp_controller_get_now_playing_info(avrcp_cid);
976             break;
977         case 'k':
978             printf(" - play\n");
979             status = avrcp_controller_play(avrcp_cid);
980             break;
981         case 'K':
982             printf(" - stop\n");
983             status = avrcp_controller_stop(avrcp_cid);
984             break;
985         case 'L':
986             printf(" - pause\n");
987             status = avrcp_controller_pause(avrcp_cid);
988             break;
989         case 'u':
990             printf(" - start fast forward\n");
991             status = avrcp_controller_press_and_hold_fast_forward(avrcp_cid);
992             break;
993         case 'U':
994             printf(" - stop fast forward\n");
995             status = avrcp_controller_release_press_and_hold_cmd(avrcp_cid);
996             break;
997         case 'n':
998             printf(" - start rewind\n");
999             status = avrcp_controller_press_and_hold_rewind(avrcp_cid);
1000             break;
1001         case 'N':
1002             printf(" - stop rewind\n");
1003             status = avrcp_controller_release_press_and_hold_cmd(avrcp_cid);
1004             break;
1005         case 'i':
1006             printf(" - forward\n");
1007             status = avrcp_controller_forward(avrcp_cid);
1008             break;
1009         case 'I':
1010             printf(" - backward\n");
1011             status = avrcp_controller_backward(avrcp_cid);
1012             break;
1013         case 'M':
1014             printf(" - mute\n");
1015             status = avrcp_controller_mute(avrcp_cid);
1016             break;
1017         case 'r':
1018             printf(" - skip\n");
1019             status = avrcp_controller_skip(avrcp_cid);
1020             break;
1021         case 'q':
1022             printf(" - query repeat and shuffle mode\n");
1023             status = avrcp_controller_query_shuffle_and_repeat_modes(avrcp_cid);
1024             break;
1025         case 'v':
1026             printf(" - repeat single track\n");
1027             status = avrcp_controller_set_repeat_mode(avrcp_cid, AVRCP_REPEAT_MODE_SINGLE_TRACK);
1028             break;
1029         case 'x':
1030             printf(" - repeat all tracks\n");
1031             status = avrcp_controller_set_repeat_mode(avrcp_cid, AVRCP_REPEAT_MODE_ALL_TRACKS);
1032             break;
1033         case 'X':
1034             printf(" - disable repeat mode\n");
1035             status = avrcp_controller_set_repeat_mode(avrcp_cid, AVRCP_REPEAT_MODE_OFF);
1036             break;
1037         case 'z':
1038             printf(" - shuffle all tracks\n");
1039             status = avrcp_controller_set_shuffle_mode(avrcp_cid, AVRCP_SHUFFLE_MODE_ALL_TRACKS);
1040             break;
1041         case 'Z':
1042             printf(" - disable shuffle mode\n");
1043             status = avrcp_controller_set_shuffle_mode(avrcp_cid, AVRCP_SHUFFLE_MODE_OFF);
1044             break;
1045         case 'a':
1046             printf("AVRCP: enable notification TRACK_CHANGED\n");
1047             avrcp_controller_enable_notification(avrcp_cid, AVRCP_NOTIFICATION_EVENT_TRACK_CHANGED);
1048             break;
1049         case 'A':
1050             printf("AVRCP: disable notification TRACK_CHANGED\n");
1051             avrcp_controller_disable_notification(avrcp_cid, AVRCP_NOTIFICATION_EVENT_TRACK_CHANGED);
1052             break;
1053         case 'R':
1054             printf("AVRCP: enable notification PLAYBACK_POS_CHANGED\n");
1055             avrcp_controller_enable_notification(avrcp_cid, AVRCP_NOTIFICATION_EVENT_PLAYBACK_POS_CHANGED);
1056             break;
1057         case 'P':
1058             printf("AVRCP: disable notification PLAYBACK_POS_CHANGED\n");
1059             avrcp_controller_disable_notification(avrcp_cid, AVRCP_NOTIFICATION_EVENT_PLAYBACK_POS_CHANGED);
1060             break;
1061          case 's':
1062             printf("AVRCP: send long button press REWIND\n");
1063             avrcp_controller_start_press_and_hold_cmd(avrcp_cid, AVRCP_OPERATION_ID_REWIND);
1064             break;
1065         case 'S':
1066             printf("AVRCP: release long button press REWIND\n");
1067             avrcp_controller_release_press_and_hold_cmd(avrcp_cid);
1068             break;
1069         default:
1070             show_usage();
1071             return;
1072     }
1073     if (status != ERROR_CODE_SUCCESS){
1074         printf("Could not perform command, status 0x%02x\n", status);
1075     }
1076 }
1077 #endif
1078 
1079 int btstack_main(int argc, const char * argv[]);
1080 int btstack_main(int argc, const char * argv[]){
1081     UNUSED(argc);
1082     (void)argv;
1083 
1084     a2dp_and_avrcp_setup();
1085 
1086 #ifdef HAVE_BTSTACK_STDIN
1087     // parse human readable Bluetooth address
1088     sscanf_bd_addr(device_addr_string, device_addr);
1089     btstack_stdin_setup(stdin_process);
1090 #endif
1091 
1092     // turn on!
1093     printf("Starting BTstack ...\n");
1094     hci_power_control(HCI_POWER_ON);
1095     return 0;
1096 }
1097 /* EXAMPLE_END */
1098