Is There a Way to Save the Audio Sound Level?

[AUTACE]

Hi there,
first of all, thank you so much for providing this insane library, it has helped me a lot so far!

But nevertheless, I have come upon an issue I couldn't find a solution for. Every time I reconnect to the ESP, the audio sound level of my device is reset to zero. I have tried different devices (iOS, Android) but they all seem to have the same issue.

As this only happens with the ESP32 and works just fine on all other Bluetooth devices, I wanted to ask, if there's a possibility to save the sound level internally, so it automatically adopts it when reconnecting?

Thanks in advance!

Also here's my code in case this helps:

#include "BluetoothA2DPSinkQueued.h"

BluetoothA2DPSinkQueued a2dp_sink;

// Globale Variablen zur Speicherung des aktuellen Zustands
bool isConnected = false;
bool isAudioStarted = false;

void setup() {
    static const i2s_config_t i2s_config = {
        .mode = (i2s_mode_t) (I2S_MODE_MASTER | I2S_MODE_TX | I2S_MODE_DAC_BUILT_IN),
        .sample_rate = 44100, // corrected by info from bluetooth
        .bits_per_sample = (i2s_bits_per_sample_t) 16, /* the DAC module will only take the 8bits from MSB */
        .channel_format = I2S_CHANNEL_FMT_RIGHT_LEFT,
        .communication_format = (i2s_comm_format_t)I2S_COMM_FORMAT_STAND_MSB,
        .intr_alloc_flags = 0, // default interrupt priority
        .dma_buf_count = 8,
        .dma_buf_len = 64,
        .use_apll = false
    };
    Serial.begin(115200);
    a2dp_sink.set_i2s_config(i2s_config);
    a2dp_sink.set_on_connection_state_changed(connection_state_changed);
    a2dp_sink.set_on_audio_state_changed(audio_state_changed);
    a2dp_sink.set_auto_reconnect(true);
    a2dp_sink.start("Music");
}

void loop() {
    delay(1000);
}


// für esp_a2d_connection_state_t siehe https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-reference/bluetooth/esp_a2dp.html#_CPPv426esp_a2d_connection_state_t
void connection_state_changed(esp_a2d_connection_state_t state, void *ptr){
    isConnected = (state == ESP_A2D_CONNECTION_STATE_CONNECTED);
}

// für esp_a2d_audio_state_t siehe https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-reference/bluetooth/esp_a2dp.html#_CPPv421esp_a2d_audio_state_t
void audio_state_changed(esp_a2d_audio_state_t state, void *ptr){
    isAudioStarted = (state == ESP_A2D_AUDIO_STATE_STARTED);
}

[pschatzmann]

It is my understanding that the volume is sent by your phone, so I don't see any point is saving this on the esp32 when it will be overwritten anyhow.

Apart from this: did you try to call set_volume() to define an initial volume if the phone does not provide any volume ?