yunTune/main/bt_app_av.c

/*
 * SPDX-FileCopyrightText: 2021-2022 Espressif Systems (Shanghai) CO LTD
 *
 * SPDX-License-Identifier: Unlicense OR CC0-1.0
 */

#include <stdint.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <inttypes.h>
#include "esp_log.h"

#include "bt_app_core.h"
#include "bt_app_av.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"

#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#ifdef CONFIG_EXAMPLE_A2DP_SINK_OUTPUT_INTERNAL_DAC
#include "driver/dac_continuous.h"
#else
#include "driver/i2s_std.h"
#endif

#include "sys/lock.h"

#include "audio.h"

/* AVRCP used transaction labels */
#define APP_RC_CT_TL_GET_CAPS            (0)
#define APP_RC_CT_TL_GET_META_DATA       (1)
#define APP_RC_CT_TL_RN_TRACK_CHANGE     (2)
#define APP_RC_CT_TL_RN_PLAYBACK_CHANGE  (3)
#define APP_RC_CT_TL_RN_PLAY_POS_CHANGE  (4)

/* Application layer causes delay value */
#define APP_DELAY_VALUE                  50  // 5ms

/*******************************
 * STATIC FUNCTION DECLARATIONS
 ******************************/

/* allocate new meta buffer */
static void bt_app_alloc_meta_buffer(esp_avrc_ct_cb_param_t *param);
/* handler for new track is loaded */
static void bt_av_new_track(void);
/* handler for track status change */
static void bt_av_playback_changed(void);
/* handler for track playing position change */
static void bt_av_play_pos_changed(void);
/* notification event handler */
static void bt_av_notify_evt_handler(uint8_t event_id, esp_avrc_rn_param_t *event_parameter);
/* installation for i2s */
static void bt_i2s_driver_install(void);
/* uninstallation for i2s */
static void bt_i2s_driver_uninstall(void);
/* set volume by remote controller */
static void volume_set_by_controller(uint8_t volume);
/* set volume by local host */
static void volume_set_by_local_host(uint8_t volume);
/* simulation volume change */
static void volume_change_simulation(void *arg);
/* a2dp event handler */
static void bt_av_hdl_a2d_evt(uint16_t event, void *p_param);
/* avrc controller event handler */
static void bt_av_hdl_avrc_ct_evt(uint16_t event, void *p_param);
/* avrc target event handler */
static void bt_av_hdl_avrc_tg_evt(uint16_t event, void *p_param);

/*******************************
 * STATIC VARIABLE DEFINITIONS
 ******************************/

static uint32_t s_pkt_cnt = 0;               /* count for audio packet */
static esp_a2d_audio_state_t s_audio_state = ESP_A2D_AUDIO_STATE_STOPPED;
                                             /* audio stream datapath state */
static const char *s_a2d_conn_state_str[] = {"Disconnected", "Connecting", "Connected", "Disconnecting"};
                                             /* connection state in string */
static const char *s_a2d_audio_state_str[] = {"Suspended", "Started"};
                                             /* audio stream datapath state in string */
static esp_avrc_rn_evt_cap_mask_t s_avrc_peer_rn_cap;
                                             /* AVRC target notification capability bit mask */
static _lock_t s_volume_lock;
// static TaskHandle_t s_vcs_task_hdl = NULL;    /* handle for volume change simulation task */
// 定义音量增益（全局变量需在外部声明）
               /* local volume value */
static bool s_volume_notify;                 /* notify volume change or not */
#ifndef CONFIG_EXAMPLE_A2DP_SINK_OUTPUT_INTERNAL_DAC
i2s_chan_handle_t tx_chan = NULL;
#else
dac_continuous_handle_t tx_chan;
#endif

/********************************
 * STATIC FUNCTION DEFINITIONS
 *******************************/

static void bt_app_alloc_meta_buffer(esp_avrc_ct_cb_param_t *param)
{
    esp_avrc_ct_cb_param_t *rc = (esp_avrc_ct_cb_param_t *)(param);
    uint8_t *attr_text = (uint8_t *) malloc (rc->meta_rsp.attr_length + 1);

    memcpy(attr_text, rc->meta_rsp.attr_text, rc->meta_rsp.attr_length);
    attr_text[rc->meta_rsp.attr_length] = 0;
    rc->meta_rsp.attr_text = attr_text;
}

static void bt_av_new_track(void)
{
    /* request metadata */
    uint8_t attr_mask = ESP_AVRC_MD_ATTR_TITLE |
                        ESP_AVRC_MD_ATTR_ARTIST |
                        ESP_AVRC_MD_ATTR_ALBUM |
                        ESP_AVRC_MD_ATTR_GENRE;
    esp_avrc_ct_send_metadata_cmd(APP_RC_CT_TL_GET_META_DATA, attr_mask);

    /* register notification if peer support the event_id */
    if (esp_avrc_rn_evt_bit_mask_operation(ESP_AVRC_BIT_MASK_OP_TEST, &s_avrc_peer_rn_cap,
                                           ESP_AVRC_RN_TRACK_CHANGE)) {
        esp_avrc_ct_send_register_notification_cmd(APP_RC_CT_TL_RN_TRACK_CHANGE,
                                                   ESP_AVRC_RN_TRACK_CHANGE, 0);
    }
}

static void bt_av_playback_changed(void)
{
    /* register notification if peer support the event_id */
    if (esp_avrc_rn_evt_bit_mask_operation(ESP_AVRC_BIT_MASK_OP_TEST, &s_avrc_peer_rn_cap,
                                           ESP_AVRC_RN_PLAY_STATUS_CHANGE)) {
        esp_avrc_ct_send_register_notification_cmd(APP_RC_CT_TL_RN_PLAYBACK_CHANGE,
                                                   ESP_AVRC_RN_PLAY_STATUS_CHANGE, 0);
    }
}

static void bt_av_play_pos_changed(void)
{
    /* register notification if peer support the event_id */
    if (esp_avrc_rn_evt_bit_mask_operation(ESP_AVRC_BIT_MASK_OP_TEST, &s_avrc_peer_rn_cap,
                                           ESP_AVRC_RN_PLAY_POS_CHANGED)) {
        esp_avrc_ct_send_register_notification_cmd(APP_RC_CT_TL_RN_PLAY_POS_CHANGE,
                                                   ESP_AVRC_RN_PLAY_POS_CHANGED, 10);
    }
}

static void bt_av_notify_evt_handler(uint8_t event_id, esp_avrc_rn_param_t *event_parameter)
{
    switch (event_id) {
    /* when new track is loaded, this event comes */
    case ESP_AVRC_RN_TRACK_CHANGE:
        bt_av_new_track();
        break;
    /* when track status changed, this event comes */
    case ESP_AVRC_RN_PLAY_STATUS_CHANGE:
        ESP_LOGI(BT_AV_TAG, "Playback status changed: 0x%x", event_parameter->playback);
        bt_av_playback_changed();
        break;
    /* when track playing position changed, this event comes */
    case ESP_AVRC_RN_PLAY_POS_CHANGED:
        ESP_LOGI(BT_AV_TAG, "Play position changed: %"PRIu32"-ms", event_parameter->play_pos);
        bt_av_play_pos_changed();
        break;
    /* others */
    default:
        ESP_LOGI(BT_AV_TAG, "unhandled event: %d", event_id);
        break;
    }
}

void bt_i2s_driver_install(void)
{
#ifdef CONFIG_EXAMPLE_A2DP_SINK_OUTPUT_INTERNAL_DAC
    dac_continuous_config_t cont_cfg = {
        .chan_mask = DAC_CHANNEL_MASK_ALL,
        .desc_num = 8,
        .buf_size = 2048,
        .freq_hz = 44100,
        .offset = 127,
        .clk_src = DAC_DIGI_CLK_SRC_DEFAULT,   // Using APLL as clock source to get a wider frequency range
        .chan_mode = DAC_CHANNEL_MODE_ALTER,
    };
    /* Allocate continuous channels */
    ESP_ERROR_CHECK(dac_continuous_new_channels(&cont_cfg, &tx_chan));
    /* Enable the continuous channels */
    ESP_ERROR_CHECK(dac_continuous_enable(tx_chan));
#else
    i2s_chan_config_t chan_cfg = I2S_CHANNEL_DEFAULT_CONFIG(I2S_NUM_0, I2S_ROLE_MASTER);
    chan_cfg.auto_clear = true;
    i2s_std_config_t std_cfg = {
        .clk_cfg = I2S_STD_CLK_DEFAULT_CONFIG(44100),
        .slot_cfg = I2S_STD_MSB_SLOT_DEFAULT_CONFIG(I2S_DATA_BIT_WIDTH_16BIT, I2S_SLOT_MODE_STEREO),
        .gpio_cfg = {
            .mclk = I2S_MCK_IO,//3
            .bclk = I2S_BCK_IO,//26
            .ws = I2S_WS_IO,//25
            .dout = I2S_DO_IO,//27
            .din = I2S_GPIO_UNUSED,
            .invert_flags = {
                .mclk_inv = false,
                .bclk_inv = false,
                .ws_inv = false,
            },
        },
    };
    /* enable I2S */
    ESP_ERROR_CHECK(i2s_new_channel(&chan_cfg, &tx_chan, NULL));
    ESP_ERROR_CHECK(i2s_channel_init_std_mode(tx_chan, &std_cfg));
    ESP_ERROR_CHECK(i2s_channel_enable(tx_chan));
#endif
}

void bt_i2s_driver_uninstall(void)
{
#ifdef CONFIG_EXAMPLE_A2DP_SINK_OUTPUT_INTERNAL_DAC
    ESP_ERROR_CHECK(dac_continuous_disable(tx_chan));
    ESP_ERROR_CHECK(dac_continuous_del_channels(tx_chan));
#else
    ESP_ERROR_CHECK(i2s_channel_disable(tx_chan));
    ESP_ERROR_CHECK(i2s_del_channel(tx_chan));
#endif
}

static void volume_set_by_controller(uint8_t volume)
{
    ESP_LOGI(BT_RC_TG_TAG, "Volume is set by remote controller to: %"PRIu32"%%", (uint32_t)volume * 100 / 0x7f);
    /* set the volume in protection of lock */
    _lock_acquire(&s_volume_lock);
    s_volume = volume;
    _lock_release(&s_volume_lock);
}

static void volume_set_by_local_host(uint8_t volume)
{
    ESP_LOGI(BT_RC_TG_TAG, "Volume is set locally to: %"PRIu32"%%", (uint32_t)volume * 100 / 0x7f);
    /* set the volume in protection of lock */
    _lock_acquire(&s_volume_lock);
    s_volume = volume;
    _lock_release(&s_volume_lock);

    /* send notification response to remote AVRCP controller */
    if (s_volume_notify) {
        esp_avrc_rn_param_t rn_param;
        rn_param.volume = s_volume;
        esp_avrc_tg_send_rn_rsp(ESP_AVRC_RN_VOLUME_CHANGE, ESP_AVRC_RN_RSP_CHANGED, &rn_param);
        s_volume_notify = false;
    }
}

static void volume_change_simulation(void *arg)
{
    ESP_LOGI(BT_RC_TG_TAG, "start volume change simulation");

    for (;;) {
        /* volume up locally every 10 seconds */
        vTaskDelay(10000 / portTICK_PERIOD_MS);
        uint8_t volume = (s_volume + 5) & 0x7f;
        volume_set_by_local_host(volume);
    }
}

static void bt_av_hdl_a2d_evt(uint16_t event, void *p_param)
{
    ESP_LOGD(BT_AV_TAG, "%s event: %d", __func__, event);

    esp_a2d_cb_param_t *a2d = NULL;

    switch (event) {
    /* when connection state changed, this event comes */
    case ESP_A2D_CONNECTION_STATE_EVT: {
        a2d = (esp_a2d_cb_param_t *)(p_param);
        uint8_t *bda = a2d->conn_stat.remote_bda;
        ESP_LOGI(BT_AV_TAG, "A2DP connection state: %s, [%02x:%02x:%02x:%02x:%02x:%02x]",
            s_a2d_conn_state_str[a2d->conn_stat.state], bda[0], bda[1], bda[2], bda[3], bda[4], bda[5]);
        if (a2d->conn_stat.state == ESP_A2D_CONNECTION_STATE_DISCONNECTED) {
            // 切换为可发现模式, 并且断开i2s驱动
            esp_bt_gap_set_scan_mode(ESP_BT_CONNECTABLE, ESP_BT_GENERAL_DISCOVERABLE);
            bt_i2s_driver_uninstall();
            bt_i2s_task_shut_down();
            // todo 自动重连回设备
            // 如果启用了自动重连，尝试重新连接
        } else if (a2d->conn_stat.state == ESP_A2D_CONNECTION_STATE_CONNECTED){
            esp_bt_gap_set_scan_mode(ESP_BT_NON_CONNECTABLE, ESP_BT_NON_DISCOVERABLE);
            bt_i2s_task_start_up();
            // 保存连接的设备信息到NVS
            // todo 获取设备名称


        } else if (a2d->conn_stat.state == ESP_A2D_CONNECTION_STATE_CONNECTING) {
            bt_i2s_driver_install();
        }
        break;
    }
    /* when audio stream transmission state changed, this event comes */
    case ESP_A2D_AUDIO_STATE_EVT: {
        a2d = (esp_a2d_cb_param_t *)(p_param);
        ESP_LOGI(BT_AV_TAG, "A2DP audio state: %s", s_a2d_audio_state_str[a2d->audio_stat.state]);
        s_audio_state = a2d->audio_stat.state;
        if (ESP_A2D_AUDIO_STATE_STARTED == a2d->audio_stat.state) {
            s_pkt_cnt = 0;
        }
        break;
    }
    /* when audio codec is configured, this event comes */
    case ESP_A2D_AUDIO_CFG_EVT: {
        a2d = (esp_a2d_cb_param_t *)(p_param);
        ESP_LOGI(BT_AV_TAG, "A2DP audio stream configuration, codec type: %d", a2d->audio_cfg.mcc.type);
        /* for now only SBC stream is supported */
        if (a2d->audio_cfg.mcc.type == ESP_A2D_MCT_SBC) {
            int sample_rate = 16000;
            int ch_count = 2;
            char oct0 = a2d->audio_cfg.mcc.cie.sbc[0];
            if (oct0 & (0x01 << 6)) {
                sample_rate = 32000;
            } else if (oct0 & (0x01 << 5)) {
                sample_rate = 44100;
            } else if (oct0 & (0x01 << 4)) {
                sample_rate = 48000;
            }

            if (oct0 & (0x01 << 3)) {
                ch_count = 1;
            }
        #ifdef CONFIG_EXAMPLE_A2DP_SINK_OUTPUT_INTERNAL_DAC
            dac_continuous_disable(tx_chan);
            dac_continuous_del_channels(tx_chan);
            dac_continuous_config_t cont_cfg = {
                .chan_mask = DAC_CHANNEL_MASK_ALL,
                .desc_num = 8,
                .buf_size = 2048,
                .freq_hz = sample_rate,
                .offset = 127,
                .clk_src = DAC_DIGI_CLK_SRC_DEFAULT,   // Using APLL as clock source to get a wider frequency range
                .chan_mode = (ch_count == 1) ? DAC_CHANNEL_MODE_SIMUL : DAC_CHANNEL_MODE_ALTER,
            };
            /* Allocate continuous channels */
            dac_continuous_new_channels(&cont_cfg, &tx_chan);
            /* Enable the continuous channels */
            dac_continuous_enable(tx_chan);
        #else
            i2s_channel_disable(tx_chan);
            i2s_std_clk_config_t clk_cfg = I2S_STD_CLK_DEFAULT_CONFIG(sample_rate);
            i2s_std_slot_config_t slot_cfg = I2S_STD_MSB_SLOT_DEFAULT_CONFIG(I2S_DATA_BIT_WIDTH_16BIT, ch_count);
            i2s_channel_reconfig_std_clock(tx_chan, &clk_cfg);
            i2s_channel_reconfig_std_slot(tx_chan, &slot_cfg);
            i2s_channel_enable(tx_chan);
        #endif
            ESP_LOGI(BT_AV_TAG, "Configure audio player: %x-%x-%x-%x",
                     a2d->audio_cfg.mcc.cie.sbc[0],
                     a2d->audio_cfg.mcc.cie.sbc[1],
                     a2d->audio_cfg.mcc.cie.sbc[2],
                     a2d->audio_cfg.mcc.cie.sbc[3]);
            ESP_LOGI(BT_AV_TAG, "Audio player configured, sample rate: %d", sample_rate);
        }
        break;
    }
    /* when a2dp init or deinit completed, this event comes */
    case ESP_A2D_PROF_STATE_EVT: {
        a2d = (esp_a2d_cb_param_t *)(p_param);
        if (ESP_A2D_INIT_SUCCESS == a2d->a2d_prof_stat.init_state) {
            ESP_LOGI(BT_AV_TAG, "A2DP PROF STATE: Init Complete");
        } else {
            ESP_LOGI(BT_AV_TAG, "A2DP PROF STATE: Deinit Complete");
        }
        break;
    }
    /* When protocol service capabilities configured, this event comes */
    case ESP_A2D_SNK_PSC_CFG_EVT: {
        a2d = (esp_a2d_cb_param_t *)(p_param);
        ESP_LOGI(BT_AV_TAG, "protocol service capabilities configured: 0x%x ", a2d->a2d_psc_cfg_stat.psc_mask);
        if (a2d->a2d_psc_cfg_stat.psc_mask & ESP_A2D_PSC_DELAY_RPT) {
            ESP_LOGI(BT_AV_TAG, "Peer device support delay reporting");
        } else {
            ESP_LOGI(BT_AV_TAG, "Peer device unsupport delay reporting");
        }
        break;
    }
    /* when set delay value completed, this event comes */
    case ESP_A2D_SNK_SET_DELAY_VALUE_EVT: {
        a2d = (esp_a2d_cb_param_t *)(p_param);
        if (ESP_A2D_SET_INVALID_PARAMS == a2d->a2d_set_delay_value_stat.set_state) {
            ESP_LOGI(BT_AV_TAG, "Set delay report value: fail");
        } else {
            ESP_LOGI(BT_AV_TAG, "Set delay report value: success, delay_value: %u * 1/10 ms", a2d->a2d_set_delay_value_stat.delay_value);
        }
        break;
    }
    /* when get delay value completed, this event comes */
    case ESP_A2D_SNK_GET_DELAY_VALUE_EVT: {
        a2d = (esp_a2d_cb_param_t *)(p_param);
        ESP_LOGI(BT_AV_TAG, "Get delay report value: delay_value: %u * 1/10 ms", a2d->a2d_get_delay_value_stat.delay_value);
        /* Default delay value plus delay caused by application layer */
        esp_a2d_sink_set_delay_value(a2d->a2d_get_delay_value_stat.delay_value + APP_DELAY_VALUE);
        break;
    }
    /* others */
    default:
        ESP_LOGE(BT_AV_TAG, "%s unhandled event: %d", __func__, event);
        break;
    }
}

static void bt_av_hdl_avrc_ct_evt(uint16_t event, void *p_param)
{
    ESP_LOGD(BT_RC_CT_TAG, "%s event: %d", __func__, event);

    esp_avrc_ct_cb_param_t *rc = (esp_avrc_ct_cb_param_t *)(p_param);

    switch (event) {
    /* when connection state changed, this event comes */
    case ESP_AVRC_CT_CONNECTION_STATE_EVT: {
        uint8_t *bda = rc->conn_stat.remote_bda;
        ESP_LOGI(BT_RC_CT_TAG, "AVRC conn_state event: state %d, [%02x:%02x:%02x:%02x:%02x:%02x]",
                 rc->conn_stat.connected, bda[0], bda[1], bda[2], bda[3], bda[4], bda[5]);

        if (rc->conn_stat.connected) {
            /* get remote supported event_ids of peer AVRCP Target */
            esp_avrc_ct_send_get_rn_capabilities_cmd(APP_RC_CT_TL_GET_CAPS);
        } else {
            /* clear peer notification capability record */
            s_avrc_peer_rn_cap.bits = 0;
        }
        break;
    }
    /* when passthrough responsed, this event comes */
    case ESP_AVRC_CT_PASSTHROUGH_RSP_EVT: {
        ESP_LOGI(BT_RC_CT_TAG, "AVRC passthrough rsp: key_code 0x%x, key_state %d, rsp_code %d", rc->psth_rsp.key_code,
                    rc->psth_rsp.key_state, rc->psth_rsp.rsp_code);
        break;
    }
    /* when metadata responsed, this event comes */
    case ESP_AVRC_CT_METADATA_RSP_EVT: {
        ESP_LOGI(BT_RC_CT_TAG, "AVRC metadata rsp: attribute id 0x%x, %s", rc->meta_rsp.attr_id, rc->meta_rsp.attr_text);
        free(rc->meta_rsp.attr_text);
        break;
    }
    /* when notified, this event comes */
    case ESP_AVRC_CT_CHANGE_NOTIFY_EVT: {
        ESP_LOGI(BT_RC_CT_TAG, "AVRC event notification: %d", rc->change_ntf.event_id);
        bt_av_notify_evt_handler(rc->change_ntf.event_id, &rc->change_ntf.event_parameter);
        break;
    }
    /* when feature of remote device indicated, this event comes */
    case ESP_AVRC_CT_REMOTE_FEATURES_EVT: {
        ESP_LOGI(BT_RC_CT_TAG, "AVRC remote features %"PRIx32", TG features %x", rc->rmt_feats.feat_mask, rc->rmt_feats.tg_feat_flag);
        break;
    }
    /* when notification capability of peer device got, this event comes */
    case ESP_AVRC_CT_GET_RN_CAPABILITIES_RSP_EVT: {
        ESP_LOGI(BT_RC_CT_TAG, "remote rn_cap: count %d, bitmask 0x%x", rc->get_rn_caps_rsp.cap_count,
                 rc->get_rn_caps_rsp.evt_set.bits);
        s_avrc_peer_rn_cap.bits = rc->get_rn_caps_rsp.evt_set.bits;
        bt_av_new_track();
        bt_av_playback_changed();
        bt_av_play_pos_changed();
        break;
    }
    /* others */
    default:
        ESP_LOGE(BT_RC_CT_TAG, "%s unhandled event: %d", __func__, event);
        break;
    }
}

static void bt_av_hdl_avrc_tg_evt(uint16_t event, void *p_param)
{
    ESP_LOGD(BT_RC_TG_TAG, "%s event: %d", __func__, event);

    esp_avrc_tg_cb_param_t *rc = (esp_avrc_tg_cb_param_t *)(p_param);

    switch (event) {
    /* when connection state changed, this event comes */
    case ESP_AVRC_TG_CONNECTION_STATE_EVT: {
        uint8_t *bda = rc->conn_stat.remote_bda;
        ESP_LOGI(BT_RC_TG_TAG, "AVRC conn_state evt: state %d, [%02x:%02x:%02x:%02x:%02x:%02x]",
                 rc->conn_stat.connected, bda[0], bda[1], bda[2], bda[3], bda[4], bda[5]);
        if (rc->conn_stat.connected) {
            /* create task to simulate volume change */
            // xTaskCreate(volume_change_simulation, "vcsTask", 2048, NULL, 5, &s_vcs_task_hdl);
        } else {
            // vTaskDelete(s_vcs_task_hdl);
            ESP_LOGI(BT_RC_TG_TAG, "Stop volume change simulation");
        }
        break;
    }
    /* when passthrough commanded, this event comes */
    case ESP_AVRC_TG_PASSTHROUGH_CMD_EVT: {
        ESP_LOGI(BT_RC_TG_TAG, "AVRC passthrough cmd: key_code 0x%x, key_state %d", rc->psth_cmd.key_code, rc->psth_cmd.key_state);
        break;
    }
    /* when absolute volume command from remote device set, this event comes */
    case ESP_AVRC_TG_SET_ABSOLUTE_VOLUME_CMD_EVT: {
        ESP_LOGI(BT_RC_TG_TAG, "AVRC set absolute volume: %d%%", (int)rc->set_abs_vol.volume * 100 / 0x7f);
        volume_set_by_controller(rc->set_abs_vol.volume);
        volume_set_by_local_host(rc->set_abs_vol.volume);
        break;
    }
    /* when notification registered, this event comes */
    case ESP_AVRC_TG_REGISTER_NOTIFICATION_EVT: {
        ESP_LOGI(BT_RC_TG_TAG, "AVRC register event notification: %d, param: 0x%"PRIx32, rc->reg_ntf.event_id, rc->reg_ntf.event_parameter);
        if (rc->reg_ntf.event_id == ESP_AVRC_RN_VOLUME_CHANGE) {
            s_volume_notify = true;
            esp_avrc_rn_param_t rn_param;
            rn_param.volume = s_volume;
            esp_avrc_tg_send_rn_rsp(ESP_AVRC_RN_VOLUME_CHANGE, ESP_AVRC_RN_RSP_INTERIM, &rn_param);
        }
        break;
    }
    /* when feature of remote device indicated, this event comes */
    case ESP_AVRC_TG_REMOTE_FEATURES_EVT: {
        ESP_LOGI(BT_RC_TG_TAG, "AVRC remote features: %"PRIx32", CT features: %x", rc->rmt_feats.feat_mask, rc->rmt_feats.ct_feat_flag);
        break;
    }
    /* others */
    default:
        ESP_LOGE(BT_RC_TG_TAG, "%s unhandled event: %d", __func__, event);
        break;
    }
}

/********************************
 * EXTERNAL FUNCTION DEFINITIONS
 *******************************/

void bt_app_a2d_cb(esp_a2d_cb_event_t event, esp_a2d_cb_param_t *param)
{
    switch (event) {
    case ESP_A2D_CONNECTION_STATE_EVT:
    case ESP_A2D_AUDIO_STATE_EVT:
    case ESP_A2D_AUDIO_CFG_EVT:
    case ESP_A2D_PROF_STATE_EVT:
    case ESP_A2D_SNK_PSC_CFG_EVT:
    case ESP_A2D_SNK_SET_DELAY_VALUE_EVT:
    case ESP_A2D_SNK_GET_DELAY_VALUE_EVT: {
        bt_app_work_dispatch(bt_av_hdl_a2d_evt, event, param, sizeof(esp_a2d_cb_param_t), NULL);
        break;
    }
    default:
        ESP_LOGE(BT_AV_TAG, "Invalid A2DP event: %d", event);
        break;
    }
}

void bt_app_a2d_data_cb(const uint8_t *data, uint32_t len)
{

    write_ringbuf(data, len);

    /* log the number every 100 packets */
    if (++s_pkt_cnt % 100 == 0) {
        ESP_LOGI(BT_AV_TAG, "Audio packet count: %"PRIu32, s_pkt_cnt);
    }
}

void bt_app_rc_ct_cb(esp_avrc_ct_cb_event_t event, esp_avrc_ct_cb_param_t *param)
{
    switch (event) {
    case ESP_AVRC_CT_METADATA_RSP_EVT:
        bt_app_alloc_meta_buffer(param);
        /* fall through */
    case ESP_AVRC_CT_CONNECTION_STATE_EVT:
    case ESP_AVRC_CT_PASSTHROUGH_RSP_EVT:
    case ESP_AVRC_CT_CHANGE_NOTIFY_EVT:
    case ESP_AVRC_CT_REMOTE_FEATURES_EVT:
    case ESP_AVRC_CT_GET_RN_CAPABILITIES_RSP_EVT: {
        bt_app_work_dispatch(bt_av_hdl_avrc_ct_evt, event, param, sizeof(esp_avrc_ct_cb_param_t), NULL);
        break;
    }
    default:
        ESP_LOGE(BT_RC_CT_TAG, "Invalid AVRC event: %d", event);
        break;
    }
}

void bt_app_rc_tg_cb(esp_avrc_tg_cb_event_t event, esp_avrc_tg_cb_param_t *param)
{
    switch (event) {
    case ESP_AVRC_TG_CONNECTION_STATE_EVT:
    case ESP_AVRC_TG_REMOTE_FEATURES_EVT:
    case ESP_AVRC_TG_PASSTHROUGH_CMD_EVT:
    case ESP_AVRC_TG_SET_ABSOLUTE_VOLUME_CMD_EVT:
    case ESP_AVRC_TG_REGISTER_NOTIFICATION_EVT:
    case ESP_AVRC_TG_SET_PLAYER_APP_VALUE_EVT:
        bt_app_work_dispatch(bt_av_hdl_avrc_tg_evt, event, param, sizeof(esp_avrc_tg_cb_param_t), NULL);
        break;
    default:
        ESP_LOGE(BT_RC_TG_TAG, "Invalid AVRC event: %d", event);
        break;
    }
}