squeezelite-esp32/main/output_bt.c

#include "squeezelite.h"
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/timers.h"
#include "nvs.h"
#include "nvs_flash.h"
#include "esp_system.h"
#include "esp_log.h"


#include "esp_bt.h"
#include "bt_app_core.h"
#include "esp_bt_main.h"
#include "esp_bt_device.h"
#include "esp_gap_bt_api.h"
#include "esp_a2dp_api.h"
#include "esp_avrc_api.h"

#define BT_AV_TAG               "BT_AV"

static log_level loglevel;

static bool running = true;

extern struct outputstate output;
extern struct buffer *outputbuf;
extern struct buffer *streambuf;

#define LOCK   mutex_lock(outputbuf->mutex)
#define UNLOCK mutex_unlock(outputbuf->mutex)

#define FRAME_BLOCK MAX_SILENCE_FRAMES

extern u8_t *silencebuf;
static u8_t *optr;

static int _write_frames(frames_t out_frames, bool silence, s32_t gainL, s32_t gainR,
								s32_t cross_gain_in, s32_t cross_gain_out, ISAMPLE_T **cross_ptr);

void set_volume(unsigned left, unsigned right) {
	LOG_DEBUG("setting internal gain left: %u right: %u", left, right);
	LOCK;
	output.gainL = left;
	output.gainR = right;
	// TODO
	output.gainL = FIXED_ONE;
	output.gainR = FIXED_ONE;
	UNLOCK;
}

/* event for handler "bt_av_hdl_stack_up */
enum {
    BT_APP_EVT_STACK_UP = 0,
};

/* A2DP global state */
enum {
    APP_AV_STATE_IDLE,
    APP_AV_STATE_DISCOVERING,
    APP_AV_STATE_DISCOVERED,
    APP_AV_STATE_UNCONNECTED,
    APP_AV_STATE_CONNECTING,
    APP_AV_STATE_CONNECTED,
    APP_AV_STATE_DISCONNECTING,
};

/* sub states of APP_AV_STATE_CONNECTED */
enum {
    APP_AV_MEDIA_STATE_IDLE,
    APP_AV_MEDIA_STATE_STARTING,
    APP_AV_MEDIA_STATE_STARTED,
    APP_AV_MEDIA_STATE_STOPPING,
};

#define BT_APP_HEART_BEAT_EVT                (0xff00)

/// handler for bluetooth stack enabled events
static void bt_av_hdl_stack_evt(uint16_t event, void *p_param);

/// callback function for A2DP source
static void bt_app_a2d_cb(esp_a2d_cb_event_t event, esp_a2d_cb_param_t *param);

/// callback function for A2DP source audio data stream
static int32_t bt_app_a2d_data_cb(uint8_t *data, int32_t len);

static void a2d_app_heart_beat(void *arg);

/// A2DP application state machine
static void bt_app_av_sm_hdlr(uint16_t event, void *param);

/* A2DP application state machine handler for each state */
static void bt_app_av_state_unconnected(uint16_t event, void *param);
static void bt_app_av_state_connecting(uint16_t event, void *param);
static void bt_app_av_state_connected(uint16_t event, void *param);
static void bt_app_av_state_disconnecting(uint16_t event, void *param);

static esp_bd_addr_t s_peer_bda = {0};
static uint8_t s_peer_bdname[ESP_BT_GAP_MAX_BDNAME_LEN + 1];
static int s_a2d_state = APP_AV_STATE_IDLE;
static int s_media_state = APP_AV_MEDIA_STATE_IDLE;
static int s_intv_cnt = 0;
static int s_connecting_intv = 0;
static uint32_t s_pkt_cnt = 0;

static TimerHandle_t s_tmr;

static char *bda2str(esp_bd_addr_t bda, char *str, size_t size)
{
    if (bda == NULL || str == NULL || size < 18) {
        return NULL;
    }

    uint8_t *p = bda;
    sprintf(str, "%02x:%02x:%02x:%02x:%02x:%02x",
            p[0], p[1], p[2], p[3], p[4], p[5]);
    return str;
}


void output_init_dac(log_level level, char *device, unsigned output_buf_size, char *params, unsigned rates[], unsigned rate_delay, unsigned idle) {
	loglevel = level;

	LOG_INFO("init output BT");

	memset(&output, 0, sizeof(output));

	output.start_frames = FRAME_BLOCK * 2;
	output.write_cb = &_write_frames;
	output.rate_delay = rate_delay;

	// ensure output rate is specified to avoid test open
	if (!rates[0]) {
		rates[0] = 44100;
	}
	/*
	 * Bluetooth audio source init Start
	 */
	bt_set_log_level(level);
	ESP_ERROR_CHECK(esp_bt_controller_mem_release(ESP_BT_MODE_BLE));

	esp_bt_controller_config_t bt_cfg = BT_CONTROLLER_INIT_CONFIG_DEFAULT();

	if (esp_bt_controller_init(&bt_cfg) != ESP_OK) {
		LOG_ERROR("%s initialize controller failed\n", __func__);
		return;
	}

	if (esp_bt_controller_enable(ESP_BT_MODE_CLASSIC_BT) != ESP_OK) {
		LOG_ERROR("%s enable controller failed\n", __func__);
		return;
	}

	if (esp_bluedroid_init() != ESP_OK) {
		LOG_ERROR("%s initialize bluedroid failed\n", __func__);
		return;
	}

	if (esp_bluedroid_enable() != ESP_OK) {
		LOG_ERROR("%s enable bluedroid failed\n", __func__);
		return;
	}
   /* create application task */
	bt_app_task_start_up();

	/* Bluetooth device name, connection mode and profile set up */
	bt_app_work_dispatch(bt_av_hdl_stack_evt, BT_APP_EVT_STACK_UP, NULL, 0, NULL);

	#if (CONFIG_BT_SSP_ENABLED == true)
	/* Set default parameters for Secure Simple Pairing */
	esp_bt_sp_param_t param_type = ESP_BT_SP_IOCAP_MODE;
	esp_bt_io_cap_t iocap = ESP_BT_IO_CAP_IO;
	esp_bt_gap_set_security_param(param_type, &iocap, sizeof(uint8_t));
	#endif

	/*
	 * Set default parameters for Legacy Pairing
	 * Use variable pin, input pin code when pairing
	 */
	esp_bt_pin_type_t pin_type = ESP_BT_PIN_TYPE_VARIABLE;
	esp_bt_pin_code_t pin_code;
	esp_bt_gap_set_pin(pin_type, 0, pin_code);

/*
 * Bluetooth audio source init Start
 */
	device = "BT";
	output_init_common(level, device, output_buf_size, rates, idle);

//#if LINUX || OSX || FREEBSD || POSIX
//	pthread_attr_t attr;
//	pthread_attr_init(&attr);
//#ifdef PTHREAD_STACK_MIN
//	pthread_attr_setstacksize(&attr, PTHREAD_STACK_MIN + OUTPUT_THREAD_STACK_SIZE);
//#endif
//	pthread_create(&thread, &attr, output_thread, NULL);
//	pthread_attr_destroy(&attr);
//#endif
//#if WIN
//	thread = CreateThread(NULL, OUTPUT_THREAD_STACK_SIZE, (LPTHREAD_START_ROUTINE)&output_thread, NULL, 0, NULL);
//#endif
}

void output_close_dac(void) {
	LOG_INFO("close output");

	LOCK;
	running = false;
	UNLOCK;

	output_close_common();
}

static int _write_frames(frames_t out_frames, bool silence, s32_t gainL, s32_t gainR,
						 s32_t cross_gain_in, s32_t cross_gain_out, ISAMPLE_T **cross_ptr) {
	
	if (!silence) {
		
		/* TODO need 16 bit fix 
		if (output.fade == FADE_ACTIVE && output.fade_dir == FADE_CROSS && *cross_ptr) {
			_apply_cross(outputbuf, out_frames, cross_gain_in, cross_gain_out, cross_ptr);
		}
		
		if (gainL != FIXED_ONE || gainR!= FIXED_ONE) {
			_apply_gain(outputbuf, out_frames, gainL, gainR);
		}
		*/

#if BYTES_PER_FRAME == 4		
		memcpy(optr, outputbuf->readp, out_frames * BYTES_PER_FRAME);
#else
	{	
		frames_t count = out_frames;
		s32_t *_iptr = (s32_t*) outputbuf->readp;
		s16_t *_optr = (s16_t*) optr;
		while (count--) {
			*_optr++ = *_iptr++ >> 16;
			*_optr++ = *_iptr++ >> 16;
		}
	}	
#endif	

	} else {

		u8_t *buf = silencebuf;

		memcpy(optr, buf, out_frames * 4);
	}
	
	optr += out_frames * 4;

	return (int)out_frames;
}

//static void *output_thread() {
//
//
//	while (running) {
//
//		//nothing to do here, for now.  Feeding the buffer is
//			usleep(500000);
//			continue;
//		}
//
//		output.device_frames = 0;
//		output.updated = gettime_ms();
//		output.frames_played_dmp = output.frames_played;
//
//		_output_frames(FRAME_BLOCK);
//
//		UNLOCK;
//
//		if (buffill) {
//// Do Stuff here
//			usleep((buffill * 1000 * 1000) / output.current_sample_rate);
//			buffill = 0;
//		} else {
//			usleep((FRAME_BLOCK * 1000 * 1000) / output.current_sample_rate);
//		}
//
//	}
//
//	return 0;
//}



static bool get_name_from_eir(uint8_t *eir, uint8_t *bdname, uint8_t *bdname_len)
{
    uint8_t *rmt_bdname = NULL;
    uint8_t rmt_bdname_len = 0;

    if (!eir) {
        return false;
    }

    rmt_bdname = esp_bt_gap_resolve_eir_data(eir, ESP_BT_EIR_TYPE_CMPL_LOCAL_NAME, &rmt_bdname_len);
    if (!rmt_bdname) {
        rmt_bdname = esp_bt_gap_resolve_eir_data(eir, ESP_BT_EIR_TYPE_SHORT_LOCAL_NAME, &rmt_bdname_len);
    }

    if (rmt_bdname) {
        if (rmt_bdname_len > ESP_BT_GAP_MAX_BDNAME_LEN) {
            rmt_bdname_len = ESP_BT_GAP_MAX_BDNAME_LEN;
        }

        if (bdname) {
            memcpy(bdname, rmt_bdname, rmt_bdname_len);
            bdname[rmt_bdname_len] = '\0';
        }
        if (bdname_len) {
            *bdname_len = rmt_bdname_len;
        }
        return true;
    }

    return false;
}

static void filter_inquiry_scan_result(esp_bt_gap_cb_param_t *param)
{
    char bda_str[18];
    uint32_t cod = 0;
    int32_t rssi = -129; /* invalid value */
    uint8_t *eir = NULL;
    esp_bt_gap_dev_prop_t *p;

    LOG_INFO("Scanned device: %s", bda2str(param->disc_res.bda, bda_str, 18));
    for (int i = 0; i < param->disc_res.num_prop; i++) {
        p = param->disc_res.prop + i;
        switch (p->type) {
        case ESP_BT_GAP_DEV_PROP_COD:
            cod = *(uint32_t *)(p->val);
            LOG_INFO("--Class of Device: 0x%x", cod);
            break;
        case ESP_BT_GAP_DEV_PROP_RSSI:
            rssi = *(int8_t *)(p->val);
            LOG_INFO("--RSSI: %d", rssi);
            break;
        case ESP_BT_GAP_DEV_PROP_EIR:
            eir = (uint8_t *)(p->val);
            break;
        case ESP_BT_GAP_DEV_PROP_BDNAME:
        default:
            break;
        }
    }

    /* search for device with MAJOR service class as "rendering" in COD */
    if (!esp_bt_gap_is_valid_cod(cod) ||
            !(esp_bt_gap_get_cod_srvc(cod) & ESP_BT_COD_SRVC_RENDERING)) {
        return;
    }

    /* search for device named "ESP_SPEAKER" in its extended inqury response */
    if (eir) {
        get_name_from_eir(eir, s_peer_bdname, NULL);
        if (strcmp((char *)s_peer_bdname, CONFIG_A2DP_SINK_NAME) != 0) {
            return;
        }

        LOG_INFO("Found a target device, address %s, name %s", bda_str, s_peer_bdname);
        s_a2d_state = APP_AV_STATE_DISCOVERED;
        memcpy(s_peer_bda, param->disc_res.bda, ESP_BD_ADDR_LEN);
        LOG_INFO("Cancel device discovery ...");
        esp_bt_gap_cancel_discovery();
    }
}


void bt_app_gap_cb(esp_bt_gap_cb_event_t event, esp_bt_gap_cb_param_t *param)
{
    switch (event) {
    case ESP_BT_GAP_DISC_RES_EVT: {
        filter_inquiry_scan_result(param);
        break;
    }
    case ESP_BT_GAP_DISC_STATE_CHANGED_EVT: {
        if (param->disc_st_chg.state == ESP_BT_GAP_DISCOVERY_STOPPED) {
            if (s_a2d_state == APP_AV_STATE_DISCOVERED) {
                s_a2d_state = APP_AV_STATE_CONNECTING;
                LOG_INFO("Device discovery stopped.");
                LOG_INFO("a2dp connecting to peer: %s", s_peer_bdname);
                esp_a2d_source_connect(s_peer_bda);
            } else {
                // not discovered, continue to discover
                LOG_INFO("Device discovery failed, continue to discover...");
                esp_bt_gap_start_discovery(ESP_BT_INQ_MODE_GENERAL_INQUIRY, 10, 0);
            }
        } else if (param->disc_st_chg.state == ESP_BT_GAP_DISCOVERY_STARTED) {
            LOG_INFO("Discovery started.");
        }
        break;
    }
    case ESP_BT_GAP_RMT_SRVCS_EVT:
    case ESP_BT_GAP_RMT_SRVC_REC_EVT:
        break;
    case ESP_BT_GAP_AUTH_CMPL_EVT: {
        if (param->auth_cmpl.stat == ESP_BT_STATUS_SUCCESS) {
            LOG_INFO("authentication success: %s", param->auth_cmpl.device_name);
            //esp_log_buffer_hex(param->auth_cmpl.bda, ESP_BD_ADDR_LEN);
        } else {
            LOG_ERROR("authentication failed, status:%d", param->auth_cmpl.stat);
        }
        break;
    }
    case ESP_BT_GAP_PIN_REQ_EVT: {
        LOG_INFO("ESP_BT_GAP_PIN_REQ_EVT min_16_digit:%d", param->pin_req.min_16_digit);
        if (param->pin_req.min_16_digit) {
            LOG_INFO("Input pin code: 0000 0000 0000 0000");
            esp_bt_pin_code_t pin_code = {0};
            esp_bt_gap_pin_reply(param->pin_req.bda, true, 16, pin_code);
        } else {
            LOG_INFO("Input pin code: 1234");
            esp_bt_pin_code_t pin_code;
            pin_code[0] = '1';
            pin_code[1] = '2';
            pin_code[2] = '3';
            pin_code[3] = '4';
            esp_bt_gap_pin_reply(param->pin_req.bda, true, 4, pin_code);
        }
        break;
    }

#if (CONFIG_BT_SSP_ENABLED == true)
    case ESP_BT_GAP_CFM_REQ_EVT:
        LOG_INFO("ESP_BT_GAP_CFM_REQ_EVT Please compare the numeric value: %d", param->cfm_req.num_val);
        esp_bt_gap_ssp_confirm_reply(param->cfm_req.bda, true);
        break;
    case ESP_BT_GAP_KEY_NOTIF_EVT:
        LOG_INFO("ESP_BT_GAP_KEY_NOTIF_EVT passkey:%d", param->key_notif.passkey);
        break;
    case ESP_BT_GAP_KEY_REQ_EVT:
        LOG_INFO("ESP_BT_GAP_KEY_REQ_EVT Please enter passkey!");
        break;
#endif

    default: {
        LOG_INFO("event: %d", event);
        break;
    }
    }
    return;
}

static void bt_av_hdl_stack_evt(uint16_t event, void *p_param)
{
	LOG_DEBUG("%s evt %d", __func__, event);
    switch (event) {
    case BT_APP_EVT_STACK_UP: {
        /* set up device name */
        char *dev_name = CONFIG_A2DP_DEV_NAME;
        esp_bt_dev_set_device_name(dev_name);

        /* register GAP callback function */
        esp_bt_gap_register_callback(bt_app_gap_cb);

        /* initialize A2DP source */
        esp_a2d_register_callback(&bt_app_a2d_cb);
        esp_a2d_source_register_data_callback(bt_app_a2d_data_cb);
        esp_a2d_source_init();

        /* set discoverable and connectable mode */
        esp_bt_gap_set_scan_mode(ESP_BT_CONNECTABLE, ESP_BT_GENERAL_DISCOVERABLE);

        /* start device discovery */
        LOG_INFO("Starting device discovery...");
        s_a2d_state = APP_AV_STATE_DISCOVERING;
        esp_bt_gap_start_discovery(ESP_BT_INQ_MODE_GENERAL_INQUIRY, 10, 0);

        /* create and start heart beat timer */
        do {
            int tmr_id = 0;
            s_tmr = xTimerCreate("connTmr", (10000 / portTICK_RATE_MS),
                               pdTRUE, (void *)tmr_id, a2d_app_heart_beat);
            xTimerStart(s_tmr, portMAX_DELAY);
        } while (0);
        break;
    }
    default:
        LOG_ERROR("%s unhandled evt %d", __func__, event);
        break;
    }
}

static void bt_app_a2d_cb(esp_a2d_cb_event_t event, esp_a2d_cb_param_t *param)
{
    bt_app_work_dispatch(bt_app_av_sm_hdlr, event, param, sizeof(esp_a2d_cb_param_t), NULL);
}

static int32_t bt_app_a2d_data_cb(uint8_t *data, int32_t len)
{
	frames_t frames;
	static int count = 0;
	static unsigned min_o = -1, max_o = 0, min_s = -1, max_s = 0;
	unsigned o, s;
	
	if (len < 0 || data == NULL) {
        return 0;
    }
    
   	LOCK;
	
/* TODO
	Normally, we would want BT to not call us back unless we are not in BUFFERING state. 
	That requires BT to not start until we are > OUTPUT_BUFFER
	// come back later, we are buffering (or stopped, need to handle that case ...) but we don't want silence 
	if (output.state <= OUTPUT_BUFFER) {
		UNLOCK;
		return 0;
	}		
*/	

   	frames = len / 4;
   	output.device_frames = 0;
   	output.updated = gettime_ms();
   	output.frames_played_dmp = output.frames_played;
	if (output.threshold < 20) output.threshold = 20;

	optr = data;
  	frames = _output_frames(frames);
	
	UNLOCK;
	
	o = _buf_used(outputbuf);
	if (o < min_o) min_o = o;
	if (o > max_o) max_o = o;
	
	s = _buf_used(streambuf);
	if (s < min_s) min_s = s;
	if (s > max_s) max_s = s;
	
	if (!(count++ & 0x1ff)) {
		LOG_INFO("frames %d (count:%d) (out:%d/%d/%d, stream:%d/%d/%d)", frames, count, max_o, min_o, o, max_s, min_s, s);
		min_o = min_s = -1;
		max_o = max_s = -0;
	}
	
	return frames * 4;
}

bool test_open(const char *device, unsigned rates[], bool userdef_rates) {
	memset(rates, 0, MAX_SUPPORTED_SAMPLERATES * sizeof(unsigned));
	if (!strcmp(device, "BT")) {
		rates[0] = 44100;
	} else {
		unsigned _rates[] = { 96000, 88200, 48000, 44100, 32000, 0 };	
		memcpy(rates, _rates, sizeof(_rates));
	}
	return true;
}

static void a2d_app_heart_beat(void *arg)
{
    bt_app_work_dispatch(bt_app_av_sm_hdlr, BT_APP_HEART_BEAT_EVT, NULL, 0, NULL);
}

static void bt_app_av_sm_hdlr(uint16_t event, void *param)
{
    LOG_INFO("%s state %d, evt 0x%x", __func__, s_a2d_state, event);
    switch (s_a2d_state) {
    case APP_AV_STATE_DISCOVERING:
    case APP_AV_STATE_DISCOVERED:
        break;
    case APP_AV_STATE_UNCONNECTED:
        bt_app_av_state_unconnected(event, param);
        break;
    case APP_AV_STATE_CONNECTING:
        bt_app_av_state_connecting(event, param);
        break;
    case APP_AV_STATE_CONNECTED:
        bt_app_av_state_connected(event, param);
        break;
    case APP_AV_STATE_DISCONNECTING:
        bt_app_av_state_disconnecting(event, param);
        break;
    default:
        LOG_ERROR("%s invalid state %d", __func__, s_a2d_state);
        break;
    }
}

static void bt_app_av_state_unconnected(uint16_t event, void *param)
{
    switch (event) {
    case ESP_A2D_CONNECTION_STATE_EVT:
    case ESP_A2D_AUDIO_STATE_EVT:
    case ESP_A2D_AUDIO_CFG_EVT:
    case ESP_A2D_MEDIA_CTRL_ACK_EVT:
        break;
    case BT_APP_HEART_BEAT_EVT: {
        uint8_t *p = s_peer_bda;
        LOG_INFO("a2dp connecting to peer: %02x:%02x:%02x:%02x:%02x:%02x",
                 p[0], p[1], p[2], p[3], p[4], p[5]);
        esp_a2d_source_connect(s_peer_bda);
        s_a2d_state = APP_AV_STATE_CONNECTING;
        s_connecting_intv = 0;
        break;
    }
    default:
        LOG_ERROR("%s unhandled evt %d", __func__, event);
        break;
    }
}

static void bt_app_av_state_connecting(uint16_t event, void *param)
{
    esp_a2d_cb_param_t *a2d = NULL;
    switch (event) {
    case ESP_A2D_CONNECTION_STATE_EVT: {
        a2d = (esp_a2d_cb_param_t *)(param);
        if (a2d->conn_stat.state == ESP_A2D_CONNECTION_STATE_CONNECTED) {
            LOG_INFO("a2dp connected");
            s_a2d_state =  APP_AV_STATE_CONNECTED;
            s_media_state = APP_AV_MEDIA_STATE_IDLE;
            esp_bt_gap_set_scan_mode(ESP_BT_NON_CONNECTABLE, ESP_BT_NON_DISCOVERABLE);
        } else if (a2d->conn_stat.state == ESP_A2D_CONNECTION_STATE_DISCONNECTED) {
            s_a2d_state =  APP_AV_STATE_UNCONNECTED;
        }
        break;
    }
    case ESP_A2D_AUDIO_STATE_EVT:
    case ESP_A2D_AUDIO_CFG_EVT:
    case ESP_A2D_MEDIA_CTRL_ACK_EVT:
        break;
    case BT_APP_HEART_BEAT_EVT:
        if (++s_connecting_intv >= 2) {
            s_a2d_state = APP_AV_STATE_UNCONNECTED;
            s_connecting_intv = 0;
        }
        break;
    default:
        LOG_ERROR("%s unhandled evt %d", __func__, event);
        break;
    }
}

static void bt_app_av_media_proc(uint16_t event, void *param)
{
    esp_a2d_cb_param_t *a2d = NULL;
    switch (s_media_state) {
    case APP_AV_MEDIA_STATE_IDLE: {
        if (event == BT_APP_HEART_BEAT_EVT) {
            LOG_INFO("a2dp media ready checking ...");
            esp_a2d_media_ctrl(ESP_A2D_MEDIA_CTRL_CHECK_SRC_RDY);
        } else if (event == ESP_A2D_MEDIA_CTRL_ACK_EVT) {
            a2d = (esp_a2d_cb_param_t *)(param);
            if (a2d->media_ctrl_stat.cmd == ESP_A2D_MEDIA_CTRL_CHECK_SRC_RDY &&
                    a2d->media_ctrl_stat.status == ESP_A2D_MEDIA_CTRL_ACK_SUCCESS) {
                LOG_INFO("a2dp media ready, starting ...");
                esp_a2d_media_ctrl(ESP_A2D_MEDIA_CTRL_START);
                s_media_state = APP_AV_MEDIA_STATE_STARTING;
            }
        }
        break;
    }
    case APP_AV_MEDIA_STATE_STARTING: {
        if (event == ESP_A2D_MEDIA_CTRL_ACK_EVT) {
            a2d = (esp_a2d_cb_param_t *)(param);
            if (a2d->media_ctrl_stat.cmd == ESP_A2D_MEDIA_CTRL_START &&
                    a2d->media_ctrl_stat.status == ESP_A2D_MEDIA_CTRL_ACK_SUCCESS) {
                LOG_INFO("a2dp media start successfully.");
                s_intv_cnt = 0;
                s_media_state = APP_AV_MEDIA_STATE_STARTED;
            } else {
                // not started succesfully, transfer to idle state
                LOG_INFO("a2dp media start failed.");
                s_media_state = APP_AV_MEDIA_STATE_IDLE;
            }
        }
        break;
    }
    case APP_AV_MEDIA_STATE_STARTED: {
        if (event == BT_APP_HEART_BEAT_EVT) {
            if (++s_intv_cnt >= 10) {
                LOG_INFO("a2dp media stopping...");
                esp_a2d_media_ctrl(ESP_A2D_MEDIA_CTRL_STOP);
                s_media_state = APP_AV_MEDIA_STATE_STOPPING;
                s_intv_cnt = 0;
            }
        }
        break;
    }
    case APP_AV_MEDIA_STATE_STOPPING: {
        if (event == ESP_A2D_MEDIA_CTRL_ACK_EVT) {
            a2d = (esp_a2d_cb_param_t *)(param);
            if (a2d->media_ctrl_stat.cmd == ESP_A2D_MEDIA_CTRL_STOP &&
                    a2d->media_ctrl_stat.status == ESP_A2D_MEDIA_CTRL_ACK_SUCCESS) {
                LOG_INFO("a2dp media stopped successfully, disconnecting...");
                s_media_state = APP_AV_MEDIA_STATE_IDLE;
                esp_a2d_source_disconnect(s_peer_bda);
                s_a2d_state = APP_AV_STATE_DISCONNECTING;
            } else {
                LOG_INFO("a2dp media stopping...");
                esp_a2d_media_ctrl(ESP_A2D_MEDIA_CTRL_STOP);
            }
        }
        break;
    }
    }
}

static void bt_app_av_state_connected(uint16_t event, void *param)
{
    esp_a2d_cb_param_t *a2d = NULL;
    switch (event) {
    case ESP_A2D_CONNECTION_STATE_EVT: {
        a2d = (esp_a2d_cb_param_t *)(param);
        if (a2d->conn_stat.state == ESP_A2D_CONNECTION_STATE_DISCONNECTED) {
            LOG_INFO("a2dp disconnected");
            s_a2d_state = APP_AV_STATE_UNCONNECTED;
            esp_bt_gap_set_scan_mode(ESP_BT_CONNECTABLE, ESP_BT_GENERAL_DISCOVERABLE);
        }
        break;
    }
    case ESP_A2D_AUDIO_STATE_EVT: {
        a2d = (esp_a2d_cb_param_t *)(param);
        if (ESP_A2D_AUDIO_STATE_STARTED == a2d->audio_stat.state) {
            s_pkt_cnt = 0;
        }
        break;
    }
    case ESP_A2D_AUDIO_CFG_EVT:
        // not suppposed to occur for A2DP source
        break;
    case ESP_A2D_MEDIA_CTRL_ACK_EVT:
    case BT_APP_HEART_BEAT_EVT: {
        bt_app_av_media_proc(event, param);
        break;
    }
    default:
        LOG_ERROR("%s unhandled evt %d", __func__, event);
        break;
    }
}

static void bt_app_av_state_disconnecting(uint16_t event, void *param)
{
    esp_a2d_cb_param_t *a2d = NULL;
    switch (event) {
    case ESP_A2D_CONNECTION_STATE_EVT: {
        a2d = (esp_a2d_cb_param_t *)(param);
        if (a2d->conn_stat.state == ESP_A2D_CONNECTION_STATE_DISCONNECTED) {
            LOG_INFO("a2dp disconnected");
            s_a2d_state =  APP_AV_STATE_UNCONNECTED;
            esp_bt_gap_set_scan_mode(ESP_BT_CONNECTABLE, ESP_BT_GENERAL_DISCOVERABLE);
        }
        break;
    }
    case ESP_A2D_AUDIO_STATE_EVT:
    case ESP_A2D_AUDIO_CFG_EVT:
    case ESP_A2D_MEDIA_CTRL_ACK_EVT:
    case BT_APP_HEART_BEAT_EVT:
        break;
    default:
        LOG_ERROR("%s unhandled evt %d", __func__, event);
        break;
    }
}