/*

* Copyright (C) 2023 BlueKitchen GmbH

*

* Redistribution and use in source and binary forms, with or without

* modification, are permitted provided that the following conditions

* are met:

*

* 1. Redistributions of source code must retain the above copyright

* notice, this list of conditions and the following disclaimer.

* 2. Redistributions in binary form must reproduce the above copyright

* notice, this list of conditions and the following disclaimer in the

* documentation and/or other materials provided with the distribution.

* 3. Neither the name of the copyright holders nor the names of

* contributors may be used to endorse or promote products derived

* from this software without specific prior written permission.

* 4. Any redistribution, use, or modification is done solely for

* personal benefit and not for any commercial purpose or for

* monetary gain.

*

* THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS

* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS

* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL BLUEKITCHEN

* GMBH OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,

* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,

* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS

* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED

* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,

* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF

* THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

* SUCH DAMAGE.

*

* Please inquire about commercial licensing options at

* contact@bluekitchen-gmbh.com

*

*/

#define BTSTACK_FILE__ "a2dp_sink_demo.c"

/*

* a2dp_sink_demo.c

*/

// *****************************************************************************

/* EXAMPLE_START(a2dp_sink_demo): A2DP Sink - Receive Audio Stream and Control Playback

*

* @text This A2DP Sink example demonstrates how to use the A2DP Sink service to

* receive an audio data stream from a remote A2DP Source device. In addition,

* the AVRCP Controller is used to get information on currently played media,

* such are title, artist and album, as well as to control the playback,

* i.e. to play, stop, repeat, etc. If HAVE_BTSTACK_STDIN is set, press SPACE on

* the console to show the available AVDTP and AVRCP commands.

*

* @text To test with a remote device, e.g. a mobile phone,

* pair from the remote device with the demo, then start playing music on the remote device.

* Alternatively, set the device_addr_string to the Bluetooth address of your

* remote device in the code, and call connect from the UI.

*

* @text For more info on BTstack audio, see our blog post

* [A2DP Sink and Source on STM32 F4 Discovery Board](http://bluekitchen-gmbh.com/a2dp-sink-and-source-on-stm32-f4-discovery-board/).

*

*/

// *****************************************************************************

#include <inttypes.h>

#include <stdint.h>

#include <stdio.h>

#include <string.h>

#include "btstack.h"

#include "btstack_resample.h"

//#define AVRCP_BROWSING_ENABLED

#ifdef HAVE_BTSTACK_STDIN

#include "btstack_stdin.h"

#endif

#ifdef HAVE_BTSTACK_AUDIO_EFFECTIVE_SAMPLERATE

#include "btstack_sample_rate_compensation.h"

#endif

#include "btstack_ring_buffer.h"

#ifdef HAVE_POSIX_FILE_IO

#include "wav_util.h"

#define STORE_TO_WAV_FILE

#ifdef _MSC_VER

// ignore deprecated warning for fopen

#pragma warning(disable : 4996)

#endif

#endif

#define NUM_CHANNELS 2

#define BYTES_PER_FRAME (2*NUM_CHANNELS)

#define MAX_SBC_FRAME_SIZE 120

#ifdef HAVE_BTSTACK_STDIN

static const char * device_addr_string = "00:1B:DC:08:E2:72"; // pts v5.0

static bd_addr_t device_addr;

#endif

#ifdef HAVE_BTSTACK_AUDIO_EFFECTIVE_SAMPLERATE

static btstack_sample_rate_compensation_t sample_rate_compensation;

#endif

static btstack_packet_callback_registration_t hci_event_callback_registration;

static uint8_t sdp_avdtp_sink_service_buffer[150];

static uint8_t sdp_avrcp_target_service_buffer[150];

static uint8_t sdp_avrcp_controller_service_buffer[200];

static uint8_t device_id_sdp_service_buffer[100];

// we support all configurations with bitpool 2-53

static uint8_t media_sbc_codec_capabilities[] = {

0xFF,//(AVDTP_SBC_44100 << 4) | AVDTP_SBC_STEREO,

0xFF,//(AVDTP_SBC_BLOCK_LENGTH_16 << 4) | (AVDTP_SBC_SUBBANDS_8 << 2) | AVDTP_SBC_ALLOCATION_METHOD_LOUDNESS,

2, 53

};

// WAV File

#ifdef STORE_TO_WAV_FILE

static uint32_t audio_frame_count = 0;

static char * wav_filename = "a2dp_sink_demo.wav";

#endif

// SBC Decoder for WAV file or live playback

static const btstack_sbc_decoder_t * sbc_decoder_instance;

static btstack_sbc_decoder_bluedroid_t sbc_decoder_context;

// ring buffer for SBC Frames

// below 30: add samples, 30-40: fine, above 40: drop samples

#define OPTIMAL_FRAMES_MIN 60

#define OPTIMAL_FRAMES_MAX 80

#define ADDITIONAL_FRAMES 30

static uint8_t sbc_frame_storage[(OPTIMAL_FRAMES_MAX + ADDITIONAL_FRAMES) * MAX_SBC_FRAME_SIZE];

static btstack_ring_buffer_t sbc_frame_ring_buffer;

static unsigned int sbc_frame_size;

// overflow buffer for not fully used sbc frames, with additional frames for resampling

static uint8_t decoded_audio_storage[(128+16) * BYTES_PER_FRAME];

static btstack_ring_buffer_t decoded_audio_ring_buffer;

static int media_initialized = 0;

static int audio_stream_started;

#ifdef HAVE_BTSTACK_AUDIO_EFFECTIVE_SAMPLERATE

static int l2cap_stream_started;

#endif

static btstack_resample_t resample_instance;

// temp storage of lower-layer request for audio samples

static int16_t * request_buffer;

static int request_frames;

// sink state

static int volume_percentage = 0;

static avrcp_battery_status_t battery_status = AVRCP_BATTERY_STATUS_WARNING;

#ifdef ENABLE_AVRCP_COVER_ART

static char a2dp_sink_demo_image_handle[8];

static avrcp_cover_art_client_t a2dp_sink_demo_cover_art_client;

static bool a2dp_sink_demo_cover_art_client_connected;

static uint16_t a2dp_sink_demo_cover_art_cid;

static uint8_t a2dp_sink_demo_ertm_buffer[2000];

static l2cap_ertm_config_t a2dp_sink_demo_ertm_config = {

1, // ertm mandatory

2, // max transmit, some tests require > 1

2000,

12000,

512, // l2cap ertm mtu

2,

2,

1, // 16-bit FCS

};

static bool a2dp_sink_cover_art_download_active;

static uint32_t a2dp_sink_cover_art_file_size;

#ifdef HAVE_POSIX_FILE_IO

static const char * a2dp_sink_demo_thumbnail_path = "cover.jpg";

static FILE * a2dp_sink_cover_art_file;

#endif

#endif

typedef struct {

uint8_t reconfigure;

uint8_t num_channels;

uint16_t sampling_frequency;

uint8_t block_length;

uint8_t subbands;

uint8_t min_bitpool_value;

uint8_t max_bitpool_value;

btstack_sbc_channel_mode_t channel_mode;

btstack_sbc_allocation_method_t allocation_method;

} media_codec_configuration_sbc_t;

typedef enum {

STREAM_STATE_CLOSED,

STREAM_STATE_OPEN,

STREAM_STATE_PLAYING,

STREAM_STATE_PAUSED,

} stream_state_t;

typedef struct {

uint8_t a2dp_local_seid;

uint8_t media_sbc_codec_configuration[4];

} a2dp_sink_demo_stream_endpoint_t;

static a2dp_sink_demo_stream_endpoint_t a2dp_sink_demo_stream_endpoint;

typedef struct {

bd_addr_t addr;

uint16_t a2dp_cid;

uint8_t a2dp_local_seid;

stream_state_t stream_state;

media_codec_configuration_sbc_t sbc_configuration;

} a2dp_sink_demo_a2dp_connection_t;

static a2dp_sink_demo_a2dp_connection_t a2dp_sink_demo_a2dp_connection;

typedef struct {

bd_addr_t addr;

uint16_t avrcp_cid;

bool playing;

uint16_t notifications_supported_by_target;

} a2dp_sink_demo_avrcp_connection_t;

static a2dp_sink_demo_avrcp_connection_t a2dp_sink_demo_avrcp_connection;

/* @section Main Application Setup

*

* @text The Listing MainConfiguration shows how to set up AD2P Sink and AVRCP services.

* Besides calling init() method for each service, you'll also need to register several packet handlers:

* - hci_packet_handler - handles legacy pairing, here by using fixed '0000' pin code.

* - 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).

* - 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.

* - avrcp_packet_handler - receives AVRCP connect/disconnect event.

* - avrcp_controller_packet_handler - receives answers for sent AVRCP commands.

* - avrcp_target_packet_handler - receives AVRCP commands, and registered notifications.

* - 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.

*

* @text To announce A2DP Sink and AVRCP services, you need to create corresponding

* SDP records and register them with the SDP service.

*

* @text Note, currently only the SBC codec is supported.

* If you want to store the audio data in a file, you'll need to define STORE_TO_WAV_FILE.

* 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.

* The initialization of the SBC decoder requires a callback that handles PCM data:

* - handle_pcm_data - handles PCM audio frames. Here, they are stored in a wav file if STORE_TO_WAV_FILE is defined, and/or played using the audio library.

*/

/* LISTING_START(MainConfiguration): Setup Audio Sink and AVRCP services */

static void hci_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);

static void a2dp_sink_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t event_size);

static void handle_l2cap_media_data_packet(uint8_t seid, uint8_t *packet, uint16_t size);

static void avrcp_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);

static void avrcp_controller_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);

static void avrcp_target_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);

#ifdef HAVE_BTSTACK_STDIN

static void stdin_process(char cmd);

#endif

static int setup_demo(void){

// init protocols

l2cap_init();

sdp_init();

#ifdef ENABLE_BLE

// Initialize LE Security Manager. Needed for cross-transport key derivation

sm_init();

#endif

#ifdef ENABLE_AVRCP_COVER_ART

goep_client_init();

avrcp_cover_art_client_init();

#endif

// Init profiles

a2dp_sink_init();

avrcp_init();

avrcp_controller_init();

avrcp_target_init();

// Configure A2DP Sink

a2dp_sink_register_packet_handler(&a2dp_sink_packet_handler);

a2dp_sink_register_media_handler(&handle_l2cap_media_data_packet);

a2dp_sink_demo_stream_endpoint_t * stream_endpoint = &a2dp_sink_demo_stream_endpoint;

avdtp_stream_endpoint_t * local_stream_endpoint = a2dp_sink_create_stream_endpoint(AVDTP_AUDIO,

AVDTP_CODEC_SBC, media_sbc_codec_capabilities, sizeof(media_sbc_codec_capabilities),

stream_endpoint->media_sbc_codec_configuration, sizeof(stream_endpoint->media_sbc_codec_configuration));

btstack_assert(local_stream_endpoint != NULL);

// - Store stream enpoint's SEP ID, as it is used by A2DP API to identify the stream endpoint

stream_endpoint->a2dp_local_seid = avdtp_local_seid(local_stream_endpoint);

// Configure AVRCP Controller + Target

avrcp_register_packet_handler(&avrcp_packet_handler);

avrcp_controller_register_packet_handler(&avrcp_controller_packet_handler);

avrcp_target_register_packet_handler(&avrcp_target_packet_handler);

// Configure SDP

// - Create and register A2DP Sink service record

memset(sdp_avdtp_sink_service_buffer, 0, sizeof(sdp_avdtp_sink_service_buffer));

a2dp_sink_create_sdp_record(sdp_avdtp_sink_service_buffer, sdp_create_service_record_handle(),

AVDTP_SINK_FEATURE_MASK_HEADPHONE, NULL, NULL);

btstack_assert(de_get_len( sdp_avdtp_sink_service_buffer) <= sizeof(sdp_avdtp_sink_service_buffer));

sdp_register_service(sdp_avdtp_sink_service_buffer);

// - Create AVRCP Controller service record and register it with SDP. We send Category 1 commands to the media player, e.g. play/pause

memset(sdp_avrcp_controller_service_buffer, 0, sizeof(sdp_avrcp_controller_service_buffer));

uint16_t controller_supported_features = 1 << AVRCP_CONTROLLER_SUPPORTED_FEATURE_CATEGORY_PLAYER_OR_RECORDER;

#ifdef AVRCP_BROWSING_ENABLED

controller_supported_features |= 1 << AVRCP_CONTROLLER_SUPPORTED_FEATURE_BROWSING;

#endif

#ifdef ENABLE_AVRCP_COVER_ART

controller_supported_features |= 1 << AVRCP_CONTROLLER_SUPPORTED_FEATURE_COVER_ART_GET_LINKED_THUMBNAIL;

#endif

avrcp_controller_create_sdp_record(sdp_avrcp_controller_service_buffer, sdp_create_service_record_handle(),

controller_supported_features, NULL, NULL);

btstack_assert(de_get_len( sdp_avrcp_controller_service_buffer) <= sizeof(sdp_avrcp_controller_service_buffer));

sdp_register_service(sdp_avrcp_controller_service_buffer);

// - Create and register A2DP Sink service record

// - We receive Category 2 commands from the media player, e.g. volume up/down

memset(sdp_avrcp_target_service_buffer, 0, sizeof(sdp_avrcp_target_service_buffer));

uint16_t target_supported_features = 1 << AVRCP_TARGET_SUPPORTED_FEATURE_CATEGORY_MONITOR_OR_AMPLIFIER;

avrcp_target_create_sdp_record(sdp_avrcp_target_service_buffer,

sdp_create_service_record_handle(), target_supported_features, NULL, NULL);

btstack_assert(de_get_len( sdp_avrcp_target_service_buffer) <= sizeof(sdp_avrcp_target_service_buffer));

sdp_register_service(sdp_avrcp_target_service_buffer);

// - Create and register Device ID (PnP) service record

memset(device_id_sdp_service_buffer, 0, sizeof(device_id_sdp_service_buffer));

device_id_create_sdp_record(device_id_sdp_service_buffer,

sdp_create_service_record_handle(), DEVICE_ID_VENDOR_ID_SOURCE_BLUETOOTH, BLUETOOTH_COMPANY_ID_BLUEKITCHEN_GMBH, 1, 1);

btstack_assert(de_get_len( device_id_sdp_service_buffer) <= sizeof(device_id_sdp_service_buffer));

sdp_register_service(device_id_sdp_service_buffer);

// Configure GAP - discovery / connection

// - Set local name with a template Bluetooth address, that will be automatically

// replaced with an actual address once it is available, i.e. when BTstack boots

// up and starts talking to a Bluetooth module.

gap_set_local_name("A2DP Sink Demo 00:00:00:00:00:00");

// - Allow to show up in Bluetooth inquiry

gap_discoverable_control(1);

// - Set Class of Device - Service Class: Audio, Major Device Class: Audio, Minor: Headphone

gap_set_class_of_device(0x200404);

// - Allow for role switch in general and sniff mode

gap_set_default_link_policy_settings( LM_LINK_POLICY_ENABLE_ROLE_SWITCH | LM_LINK_POLICY_ENABLE_SNIFF_MODE );

// - Allow for role switch on outgoing connections

// - This allows A2DP Source, e.g. smartphone, to become master when we re-connect to it.

gap_set_allow_role_switch(true);

// Register for HCI events

hci_event_callback_registration.callback = &hci_packet_handler;

hci_add_event_handler(&hci_event_callback_registration);

// Inform about audio playback / test options

#ifdef HAVE_POSIX_FILE_IO

if (!btstack_audio_sink_get_instance()){

printf("No audio playback.\n");

} else {

printf("Audio playback supported.\n");

}

#ifdef STORE_TO_WAV_FILE

printf("Audio will be stored to \'%s\' file.\n", wav_filename);

#endif

#endif

return 0;

}

/* LISTING_END */

static void playback_handler(int16_t * buffer, uint16_t num_audio_frames){

#ifdef STORE_TO_WAV_FILE

int wav_samples = num_audio_frames * NUM_CHANNELS;

int16_t * wav_buffer = buffer;

#endif

// called from lower-layer but guaranteed to be on main thread

if (sbc_frame_size == 0){

memset(buffer, 0, num_audio_frames * BYTES_PER_FRAME);

return;

}

// first fill from resampled audio

uint32_t bytes_read;

btstack_ring_buffer_read(&decoded_audio_ring_buffer, (uint8_t *) buffer, num_audio_frames * BYTES_PER_FRAME, &bytes_read);

buffer += bytes_read / NUM_CHANNELS;

num_audio_frames -= bytes_read / BYTES_PER_FRAME;

// then start decoding sbc frames using request_* globals

request_buffer = buffer;

request_frames = num_audio_frames;

while (request_frames && btstack_ring_buffer_bytes_available(&sbc_frame_ring_buffer) >= sbc_frame_size){

// decode frame

uint8_t sbc_frame[MAX_SBC_FRAME_SIZE];

btstack_ring_buffer_read(&sbc_frame_ring_buffer, sbc_frame, sbc_frame_size, &bytes_read);

sbc_decoder_instance->decode_signed_16(&sbc_decoder_context, 0, sbc_frame, sbc_frame_size);

}

#ifdef STORE_TO_WAV_FILE

audio_frame_count += num_audio_frames;

wav_writer_write_int16(wav_samples, wav_buffer);

#endif

}

static void handle_pcm_data(int16_t * data, int num_audio_frames, int num_channels, int sample_rate, void * context){

UNUSED(sample_rate);

UNUSED(context);

UNUSED(num_channels); // must be stereo == 2

const btstack_audio_sink_t * audio_sink = btstack_audio_sink_get_instance();

if (!audio_sink){

#ifdef STORE_TO_WAV_FILE

audio_frame_count += num_audio_frames;

wav_writer_write_int16(num_audio_frames * NUM_CHANNELS, data);

#endif

return;

}

// resample into request buffer - add some additional space for resampling

int16_t output_buffer[(128+16) * NUM_CHANNELS]; // 16 * 8 * 2

uint32_t resampled_frames = btstack_resample_block(&resample_instance, data, num_audio_frames, output_buffer);

// store data in btstack_audio buffer first

int frames_to_copy = btstack_min(resampled_frames, request_frames);

memcpy(request_buffer, output_buffer, frames_to_copy * BYTES_PER_FRAME);

request_frames -= frames_to_copy;

request_buffer += frames_to_copy * NUM_CHANNELS;

// and rest in ring buffer

int frames_to_store = resampled_frames - frames_to_copy;

if (frames_to_store){

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);

if (status){

printf("Error storing samples in PCM ring buffer!!!\n");

}

}

}

static int media_processing_init(media_codec_configuration_sbc_t * configuration){

if (media_initialized) return 0;

sbc_decoder_instance = btstack_sbc_decoder_bluedroid_init_instance(&sbc_decoder_context);

sbc_decoder_instance->configure(&sbc_decoder_context, SBC_MODE_STANDARD, handle_pcm_data, NULL);

#ifdef STORE_TO_WAV_FILE

wav_writer_open(wav_filename, configuration->num_channels, configuration->sampling_frequency);

#endif

btstack_ring_buffer_init(&sbc_frame_ring_buffer, sbc_frame_storage, sizeof(sbc_frame_storage));

btstack_ring_buffer_init(&decoded_audio_ring_buffer, decoded_audio_storage, sizeof(decoded_audio_storage));

btstack_resample_init(&resample_instance, configuration->num_channels);

// setup audio playback

const btstack_audio_sink_t * audio = btstack_audio_sink_get_instance();

if (audio){

audio->init(NUM_CHANNELS, configuration->sampling_frequency, &playback_handler);

}

audio_stream_started = 0;

media_initialized = 1;

return 0;

}

static void media_processing_start(void){

if (!media_initialized) return;

#ifdef HAVE_BTSTACK_AUDIO_EFFECTIVE_SAMPLERATE

btstack_sample_rate_compensation_reset( &sample_rate_compensation, btstack_run_loop_get_time_ms() );

#endif

// setup audio playback

const btstack_audio_sink_t * audio = btstack_audio_sink_get_instance();

if (audio){

audio->start_stream();

}

audio_stream_started = 1;

}

static void media_processing_pause(void){

if (!media_initialized) return;

// stop audio playback

audio_stream_started = 0;

#ifdef HAVE_BTSTACK_AUDIO_EFFECTIVE_SAMPLERATE

l2cap_stream_started = 0;

#endif

const btstack_audio_sink_t * audio = btstack_audio_sink_get_instance();

if (audio){

audio->stop_stream();

}

// discard pending data

btstack_ring_buffer_reset(&decoded_audio_ring_buffer);

btstack_ring_buffer_reset(&sbc_frame_ring_buffer);

}

static void media_processing_close(void){

if (!media_initialized) return;

media_initialized = 0;

audio_stream_started = 0;

sbc_frame_size = 0;

#ifdef HAVE_BTSTACK_AUDIO_EFFECTIVE_SAMPLERATE

l2cap_stream_started = 0;

#endif

#ifdef STORE_TO_WAV_FILE

wav_writer_close();

uint32_t total_frames_nr = sbc_decoder_context.good_frames_nr + sbc_decoder_context.bad_frames_nr + sbc_decoder_context.zero_frames_nr;

printf("WAV Writer: Decoding done. Processed %u SBC frames:\n - %d good\n - %d bad\n", total_frames_nr, sbc_decoder_context.good_frames_nr, total_frames_nr - sbc_decoder_context.good_frames_nr);

printf("WAV Writer: Wrote %u audio frames to wav file: %s\n", audio_frame_count, wav_filename);

#endif

// stop audio playback

const btstack_audio_sink_t * audio = btstack_audio_sink_get_instance();

if (audio){

printf("close stream\n");

audio->close();

}

}

/* @section Handle Media Data Packet

*

* @text Here the audio data, are received through the handle_l2cap_media_data_packet callback.

* Currently, only the SBC media codec is supported. Hence, the media data consists of the media packet header and the SBC packet.

* 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).

* If the audio stream wasn't started already and there are enough SBC frames in the ring buffer, start playback.

*/

static int read_media_data_header(uint8_t * packet, int size, int * offset, avdtp_media_packet_header_t * media_header);

static int read_sbc_header(uint8_t * packet, int size, int * offset, avdtp_sbc_codec_header_t * sbc_header);

static void handle_l2cap_media_data_packet(uint8_t seid, uint8_t *packet, uint16_t size){

UNUSED(seid);

int pos = 0;

avdtp_media_packet_header_t media_header;

if (!read_media_data_header(packet, size, &pos, &media_header)) return;

avdtp_sbc_codec_header_t sbc_header;

if (!read_sbc_header(packet, size, &pos, &sbc_header)) return;

int packet_length = size-pos;

uint8_t *packet_begin = packet+pos;

const btstack_audio_sink_t * audio = btstack_audio_sink_get_instance();

// process data right away if there's no audio implementation active, e.g. on posix systems to store as .wav

if (!audio){

sbc_decoder_instance->decode_signed_16(&sbc_decoder_context, 0, packet_begin, packet_length);

return;

}

// store sbc frame size for buffer management

sbc_frame_size = packet_length / sbc_header.num_frames;

int status = btstack_ring_buffer_write(&sbc_frame_ring_buffer, packet_begin, packet_length);

if (status != ERROR_CODE_SUCCESS){

printf("Error storing samples in SBC ring buffer!!!\n");

}

// decide on audio sync drift based on number of sbc frames in queue

int sbc_frames_in_buffer = btstack_ring_buffer_bytes_available(&sbc_frame_ring_buffer) / sbc_frame_size;

#ifdef HAVE_BTSTACK_AUDIO_EFFECTIVE_SAMPLERATE

if( !l2cap_stream_started && audio_stream_started ) {

l2cap_stream_started = 1;

btstack_sample_rate_compensation_init( &sample_rate_compensation, btstack_run_loop_get_time_ms(), a2dp_sink_demo_a2dp_connection.sbc_configuration.sampling_frequency, FLOAT_TO_Q15(1.f) );

}

// update sample rate compensation

if( audio_stream_started && (audio != NULL)) {

uint32_t resampling_factor = btstack_sample_rate_compensation_update( &sample_rate_compensation, btstack_run_loop_get_time_ms(), sbc_header.num_frames*128, audio->get_samplerate() );

btstack_resample_set_factor(&resample_instance, resampling_factor);

// printf("sbc buffer level : %"PRIu32"\n", btstack_ring_buffer_bytes_available(&sbc_frame_ring_buffer));

}

#else

uint32_t resampling_factor;

// nominal factor (fixed-point 2^16) and compensation offset

uint32_t nominal_factor = 0x10000;

uint32_t compensation = 0x00100;

if (sbc_frames_in_buffer < OPTIMAL_FRAMES_MIN){

resampling_factor = nominal_factor - compensation; // stretch samples

} else if (sbc_frames_in_buffer <= OPTIMAL_FRAMES_MAX){

resampling_factor = nominal_factor; // nothing to do

} else {

resampling_factor = nominal_factor + compensation; // compress samples

}

btstack_resample_set_factor(&resample_instance, resampling_factor);

#endif

// start stream if enough frames buffered

if (!audio_stream_started && sbc_frames_in_buffer >= OPTIMAL_FRAMES_MIN){

media_processing_start();

}

}

static int read_sbc_header(uint8_t * packet, int size, int * offset, avdtp_sbc_codec_header_t * sbc_header){

int sbc_header_len = 12; // without crc

int pos = *offset;

if (size - pos < sbc_header_len){

printf("Not enough data to read SBC header, expected %d, received %d\n", sbc_header_len, size-pos);

return 0;

}

sbc_header->fragmentation = get_bit16(packet[pos], 7);

sbc_header->starting_packet = get_bit16(packet[pos], 6);

sbc_header->last_packet = get_bit16(packet[pos], 5);

sbc_header->num_frames = packet[pos] & 0x0f;

pos++;

*offset = pos;

return 1;

}

static int read_media_data_header(uint8_t *packet, int size, int *offset, avdtp_media_packet_header_t *media_header){

int media_header_len = 12; // without crc

int pos = *offset;

if (size - pos < media_header_len){

printf("Not enough data to read media packet header, expected %d, received %d\n", media_header_len, size-pos);

return 0;

}

media_header->version = packet[pos] & 0x03;

media_header->padding = get_bit16(packet[pos],2);

media_header->extension = get_bit16(packet[pos],3);

media_header->csrc_count = (packet[pos] >> 4) & 0x0F;

pos++;

media_header->marker = get_bit16(packet[pos],0);

media_header->payload_type = (packet[pos] >> 1) & 0x7F;

pos++;

media_header->sequence_number = big_endian_read_16(packet, pos);

pos+=2;

media_header->timestamp = big_endian_read_32(packet, pos);

pos+=4;

media_header->synchronization_source = big_endian_read_32(packet, pos);

pos+=4;

*offset = pos;

return 1;

}

static void dump_sbc_configuration(media_codec_configuration_sbc_t * configuration){

printf(" - num_channels: %d\n", configuration->num_channels);

printf(" - sampling_frequency: %d\n", configuration->sampling_frequency);

printf(" - channel_mode: %d\n", configuration->channel_mode);

printf(" - block_length: %d\n", configuration->block_length);

printf(" - subbands: %d\n", configuration->subbands);

printf(" - allocation_method: %d\n", configuration->allocation_method);

printf(" - bitpool_value [%d, %d] \n", configuration->min_bitpool_value, configuration->max_bitpool_value);

printf("\n");

}

static void hci_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){

UNUSED(channel);

UNUSED(size);

if (packet_type != HCI_EVENT_PACKET) return;

if (hci_event_packet_get_type(packet) == HCI_EVENT_PIN_CODE_REQUEST) {

bd_addr_t address;

printf("Pin code request - using '0000'\n");

hci_event_pin_code_request_get_bd_addr(packet, address);

gap_pin_code_response(address, "0000");

}

}

#ifdef ENABLE_AVRCP_COVER_ART

static void a2dp_sink_demo_cover_art_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size) {

UNUSED(channel);

UNUSED(size);

uint8_t status;

uint16_t cid;

switch (packet_type){

case BIP_DATA_PACKET:

if (a2dp_sink_cover_art_download_active){

a2dp_sink_cover_art_file_size += size;

#ifdef HAVE_POSIX_FILE_IO

fwrite(packet, 1, size, a2dp_sink_cover_art_file);

#else

printf("Cover art : TODO - store %u bytes image data\n", size);

#endif

} else {

uint16_t i;

for (i=0;i<size;i++){

putchar(packet[i]);

}

printf("\n");

}

break;

case HCI_EVENT_PACKET:

switch (hci_event_packet_get_type(packet)){

case HCI_EVENT_AVRCP_META:

switch (hci_event_avrcp_meta_get_subevent_code(packet)){

case AVRCP_SUBEVENT_COVER_ART_CONNECTION_ESTABLISHED:

status = avrcp_subevent_cover_art_connection_established_get_status(packet);

cid = avrcp_subevent_cover_art_connection_established_get_cover_art_cid(packet);

if (status == ERROR_CODE_SUCCESS){

printf("Cover Art : connection established, cover art cid 0x%02x\n", cid);

a2dp_sink_demo_cover_art_client_connected = true;

} else {

printf("Cover Art : connection failed, status 0x%02x\n", status);

a2dp_sink_demo_cover_art_cid = 0;

}

break;

case AVRCP_SUBEVENT_COVER_ART_OPERATION_COMPLETE:

if (a2dp_sink_cover_art_download_active){

a2dp_sink_cover_art_download_active = false;

#ifdef HAVE_POSIX_FILE_IO

printf("Cover Art : download of '%s complete, size %u bytes'\n",

a2dp_sink_demo_thumbnail_path, a2dp_sink_cover_art_file_size);

fclose(a2dp_sink_cover_art_file);

a2dp_sink_cover_art_file = NULL;

#else

printf("Cover Art: download completed\n");

#endif

}

break;

case AVRCP_SUBEVENT_COVER_ART_CONNECTION_RELEASED:

a2dp_sink_demo_cover_art_client_connected = false;

a2dp_sink_demo_cover_art_cid = 0;

printf("Cover Art : connection released 0x%02x\n",

avrcp_subevent_cover_art_connection_released_get_cover_art_cid(packet));

break;

default:

break;

}

break;

default:

break;

}

break;

default:

break;

}

}

static uint8_t a2dp_sink_demo_cover_art_connect(void) {

uint8_t status;

status = avrcp_cover_art_client_connect(&a2dp_sink_demo_cover_art_client, a2dp_sink_demo_cover_art_packet_handler,

device_addr, a2dp_sink_demo_ertm_buffer,

sizeof(a2dp_sink_demo_ertm_buffer), &a2dp_sink_demo_ertm_config,

&a2dp_sink_demo_cover_art_cid);

return status;

}

#endif

static void avrcp_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){

UNUSED(channel);

UNUSED(size);

uint16_t local_cid;

uint8_t status;

bd_addr_t address;

a2dp_sink_demo_avrcp_connection_t * connection = &a2dp_sink_demo_avrcp_connection;

if (packet_type != HCI_EVENT_PACKET) return;

if (hci_event_packet_get_type(packet) != HCI_EVENT_AVRCP_META) return;

switch (packet[2]){

case AVRCP_SUBEVENT_CONNECTION_ESTABLISHED: {

local_cid = avrcp_subevent_connection_established_get_avrcp_cid(packet);

status = avrcp_subevent_connection_established_get_status(packet);

if (status != ERROR_CODE_SUCCESS){

printf("AVRCP: Connection failed, status 0x%02x\n", status);

connection->avrcp_cid = 0;

return;

}

connection->avrcp_cid = local_cid;

avrcp_subevent_connection_established_get_bd_addr(packet, address);

printf("AVRCP: Connected to %s, cid 0x%02x\n", bd_addr_to_str(address), connection->avrcp_cid);

#ifdef HAVE_BTSTACK_STDIN

// use address for outgoing connections

avrcp_subevent_connection_established_get_bd_addr(packet, device_addr);

#endif

avrcp_target_support_event(connection->avrcp_cid, AVRCP_NOTIFICATION_EVENT_VOLUME_CHANGED);

avrcp_target_support_event(connection->avrcp_cid, AVRCP_NOTIFICATION_EVENT_BATT_STATUS_CHANGED);

avrcp_target_battery_status_changed(connection->avrcp_cid, battery_status);

// query supported events:

avrcp_controller_get_supported_events(connection->avrcp_cid);

return;

}

case AVRCP_SUBEVENT_CONNECTION_RELEASED:

printf("AVRCP: Channel released: cid 0x%02x\n", avrcp_subevent_connection_released_get_avrcp_cid(packet));

connection->avrcp_cid = 0;

connection->notifications_supported_by_target = 0;

return;

default:

break;

}

}

static void avrcp_controller_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){

UNUSED(channel);

UNUSED(size);

// helper to print c strings

uint8_t avrcp_subevent_value[256];

uint8_t play_status;

uint8_t event_id;

a2dp_sink_demo_avrcp_connection_t * avrcp_connection = &a2dp_sink_demo_avrcp_connection;

if (packet_type != HCI_EVENT_PACKET) return;

if (hci_event_packet_get_type(packet) != HCI_EVENT_AVRCP_META) return;

if (avrcp_connection->avrcp_cid == 0) return;

memset(avrcp_subevent_value, 0, sizeof(avrcp_subevent_value));

switch (packet[2]){

case AVRCP_SUBEVENT_GET_CAPABILITY_EVENT_ID:

avrcp_connection->notifications_supported_by_target |= (1 << avrcp_subevent_get_capability_event_id_get_event_id(packet));

break;

case AVRCP_SUBEVENT_GET_CAPABILITY_EVENT_ID_DONE:

printf("AVRCP Controller: supported notifications by target:\n");

for (event_id = (uint8_t) AVRCP_NOTIFICATION_EVENT_FIRST_INDEX; event_id < (uint8_t) AVRCP_NOTIFICATION_EVENT_LAST_INDEX; event_id++){

printf(" - [%s] %s\n",

(avrcp_connection->notifications_supported_by_target & (1 << event_id)) != 0 ? "X" : " ",

avrcp_notification2str((avrcp_notification_event_id_t)event_id));

}

printf("\n\n");

// automatically enable notifications

avrcp_controller_enable_notification(avrcp_connection->avrcp_cid, AVRCP_NOTIFICATION_EVENT_PLAYBACK_STATUS_CHANGED);

avrcp_controller_enable_notification(avrcp_connection->avrcp_cid, AVRCP_NOTIFICATION_EVENT_NOW_PLAYING_CONTENT_CHANGED);

avrcp_controller_enable_notification(avrcp_connection->avrcp_cid, AVRCP_NOTIFICATION_EVENT_TRACK_CHANGED);

#ifdef ENABLE_AVRCP_COVER_ART

// image handles become invalid on player change, registe for notifications

avrcp_controller_enable_notification(a2dp_sink_demo_avrcp_connection.avrcp_cid, AVRCP_NOTIFICATION_EVENT_UIDS_CHANGED);

// trigger cover art client connection

a2dp_sink_demo_cover_art_connect();

#endif

break;

case AVRCP_SUBEVENT_NOTIFICATION_STATE:

event_id = (avrcp_notification_event_id_t)avrcp_subevent_notification_state_get_event_id(packet);

printf("AVRCP Controller: %s notification registered\n", avrcp_notification2str(event_id));

break;

case AVRCP_SUBEVENT_NOTIFICATION_PLAYBACK_POS_CHANGED:

printf("AVRCP Controller: Playback position changed, position %d ms\n", (unsigned int) avrcp_subevent_notification_playback_pos_changed_get_playback_position_ms(packet));

break;

case AVRCP_SUBEVENT_NOTIFICATION_PLAYBACK_STATUS_CHANGED:

printf("AVRCP Controller: Playback status changed %s\n", avrcp_play_status2str(avrcp_subevent_notification_playback_status_changed_get_play_status(packet)));

play_status = avrcp_subevent_notification_playback_status_changed_get_play_status(packet);

switch (play_status){

case AVRCP_PLAYBACK_STATUS_PLAYING:

avrcp_connection->playing = true;

break;

default:

avrcp_connection->playing = false;

break;

}

break;

case AVRCP_SUBEVENT_NOTIFICATION_NOW_PLAYING_CONTENT_CHANGED:

printf("AVRCP Controller: Playing content changed\n");

break;

case AVRCP_SUBEVENT_NOTIFICATION_TRACK_CHANGED:

printf("AVRCP Controller: Track changed\n");

break;

case AVRCP_SUBEVENT_NOTIFICATION_AVAILABLE_PLAYERS_CHANGED:

printf("AVRCP Controller: Available Players Changed\n");

break;

case AVRCP_SUBEVENT_SHUFFLE_AND_REPEAT_MODE:{

uint8_t shuffle_mode = avrcp_subevent_shuffle_and_repeat_mode_get_shuffle_mode(packet);

uint8_t repeat_mode = avrcp_subevent_shuffle_and_repeat_mode_get_repeat_mode(packet);

printf("AVRCP Controller: %s, %s\n", avrcp_shuffle2str(shuffle_mode), avrcp_repeat2str(repeat_mode));

break;

}

case AVRCP_SUBEVENT_NOW_PLAYING_TRACK_INFO:

printf("AVRCP Controller: Track %d\n", avrcp_subevent_now_playing_track_info_get_track(packet));

break;

case AVRCP_SUBEVENT_NOW_PLAYING_TOTAL_TRACKS_INFO:

printf("AVRCP Controller: Total Tracks %d\n", avrcp_subevent_now_playing_total_tracks_info_get_total_tracks(packet));

break;

case AVRCP_SUBEVENT_NOW_PLAYING_TITLE_INFO:

if (avrcp_subevent_now_playing_title_info_get_value_len(packet) > 0){

memcpy(avrcp_subevent_value, avrcp_subevent_now_playing_title_info_get_value(packet), avrcp_subevent_now_playing_title_info_get_value_len(packet));

printf("AVRCP Controller: Title %s\n", avrcp_subevent_value);

}

break;

case AVRCP_SUBEVENT_NOW_PLAYING_ARTIST_INFO:

if (avrcp_subevent_now_playing_artist_info_get_value_len(packet) > 0){

memcpy(avrcp_subevent_value, avrcp_subevent_now_playing_artist_info_get_value(packet), avrcp_subevent_now_playing_artist_info_get_value_len(packet));

printf("AVRCP Controller: Artist %s\n", avrcp_subevent_value);

}

break;

case AVRCP_SUBEVENT_NOW_PLAYING_ALBUM_INFO:

if (avrcp_subevent_now_playing_album_info_get_value_len(packet) > 0){

memcpy(avrcp_subevent_value, avrcp_subevent_now_playing_album_info_get_value(packet), avrcp_subevent_now_playing_album_info_get_value_len(packet));

printf("AVRCP Controller: Album %s\n", avrcp_subevent_value);

}

break;

case AVRCP_SUBEVENT_NOW_PLAYING_GENRE_INFO:

if (avrcp_subevent_now_playing_genre_info_get_value_len(packet) > 0){

memcpy(avrcp_subevent_value, avrcp_subevent_now_playing_genre_info_get_value(packet), avrcp_subevent_now_playing_genre_info_get_value_len(packet));

printf("AVRCP Controller: Genre %s\n", avrcp_subevent_value);

}

break;

case AVRCP_SUBEVENT_PLAY_STATUS:

printf("AVRCP Controller: Song length %"PRIu32" ms, Song position %"PRIu32" ms, Play status %s\n",

avrcp_subevent_play_status_get_song_length(packet),

avrcp_subevent_play_status_get_song_position(packet),

avrcp_play_status2str(avrcp_subevent_play_status_get_play_status(packet)));

break;

case AVRCP_SUBEVENT_OPERATION_COMPLETE:

printf("AVRCP Controller: %s complete\n", avrcp_operation2str(avrcp_subevent_operation_complete_get_operation_id(packet)));

break;

case AVRCP_SUBEVENT_OPERATION_START:

printf("AVRCP Controller: %s start\n", avrcp_operation2str(avrcp_subevent_operation_start_get_operation_id(packet)));

break;

case AVRCP_SUBEVENT_NOTIFICATION_EVENT_TRACK_REACHED_END:

printf("AVRCP Controller: Track reached end\n");

break;

case AVRCP_SUBEVENT_PLAYER_APPLICATION_VALUE_RESPONSE:

printf("AVRCP Controller: Set Player App Value %s\n", avrcp_ctype2str(avrcp_subevent_player_application_value_response_get_command_type(packet)));

break;

#ifdef ENABLE_AVRCP_COVER_ART

case AVRCP_SUBEVENT_NOTIFICATION_EVENT_UIDS_CHANGED:

if (a2dp_sink_demo_cover_art_client_connected){

printf("AVRCP Controller: UIDs changed -> disconnect cover art client\n");

avrcp_cover_art_client_disconnect(a2dp_sink_demo_cover_art_cid);

}

break;

case AVRCP_SUBEVENT_NOW_PLAYING_COVER_ART_INFO:

if (avrcp_subevent_now_playing_cover_art_info_get_value_len(packet) == 7){

memcpy(a2dp_sink_demo_image_handle, avrcp_subevent_now_playing_cover_art_info_get_value(packet), 7);

printf("AVRCP Controller: Cover Art %s\n", a2dp_sink_demo_image_handle);

}

break;

#endif

default:

break;

}

}

static void avrcp_volume_changed(uint8_t volume){

const btstack_audio_sink_t * audio = btstack_audio_sink_get_instance();

if (audio){

audio->set_volume(volume);

}

}

static void avrcp_target_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){

UNUSED(channel);

UNUSED(size);

if (packet_type != HCI_EVENT_PACKET) return;

if (hci_event_packet_get_type(packet) != HCI_EVENT_AVRCP_META) return;

uint8_t volume;

char const * button_state;

avrcp_operation_id_t operation_id;

switch (packet[2]){

case AVRCP_SUBEVENT_NOTIFICATION_VOLUME_CHANGED:

volume = avrcp_subevent_notification_volume_changed_get_absolute_volume(packet);

volume_percentage = volume * 100 / 127;

printf("AVRCP Target : Volume set to %d%% (%d)\n", volume_percentage, volume);

avrcp_volume_changed(volume);

break;

case AVRCP_SUBEVENT_OPERATION:

operation_id = (avrcp_operation_id_t) avrcp_subevent_operation_get_operation_id(packet);

button_state = avrcp_subevent_operation_get_button_pressed(packet) > 0 ? "PRESS" : "RELEASE";

switch (operation_id){

case AVRCP_OPERATION_ID_VOLUME_UP:

printf("AVRCP Target : VOLUME UP (%s)\n", button_state);

break;

case AVRCP_OPERATION_ID_VOLUME_DOWN: