Playback of ESP embedded audio in conjunction with BluetoothA2DPSink

[KiShiVi]

Good afternoon, I was very interested in playing back audio stored in FLASH memory using BluetoothA2DPSink. I managed to solve my problem as follows:

1. In BluetoothA2DPSink.h I changed the access modifier of bool is_output = true; from protected to public (which is very bad).
2. In BluetoothA2DPSink.h I changed the access modifier of virtual size_t write_audio(const uint8_t *data, size_t size) from protected to public.
3. In BluetoothA2DPSink.cpp in the function size_t BluetoothA2DPSink::i2s_write_data(const uint8_t *data, size_t item_size) I commented out the check if (!is_output) return item_size;.

This way I managed to get my own audio playback (even without AudioTools).

a2dp_sink.is_output = false;
a2dp_sink.write_audio(StarWars30_raw, StarWars30_raw_len);
a2dp_sink.is_output = true;

(StarWars30.h from your project's examples was taken as an example).

This code works simultaneously with a2dp_sink.start("name") and does its job perfectly. The Bluetooth sound is muted, then a fragment of audio is played back, then the Bluetooth sound is resumed.

Is it possible to modify your library in such a simple way? So that it would be possible to play your audio by interfering with the Bluetooth stream (without conflicts).

I would create Pull Request myself, but I'm sure that I may not know many nuances and consequences of my modifications (especially since they are not quite correct and made for the sake of experimentation). Thank you very much!

[KiShiVi]

Also, during testing, I found that when I turn on the ESP32 for the first time BEFORE establishing a Bluetooth connection, my method works. After connecting via Bluetooth and while playing something via Bluetooth, my method also works. But as soon as I pause the music (without breaking the connection), my method stops working and the recorded signal does not play back.
W (213932) BT_AV: i2s_write_data failed - inactive
I understand perfectly well that there is another check inside that detects the presence of a signal via Bluetooth and, if it is absent, stops playing EVERYTHING, but I am writing all this to the fact that probably when the controller is turned on for the first time, the I2S output should also be blocked (but it is open) . Perhaps you would be interested

[pschatzmann]

I don't quite understand: what is the point of this ?

Why don't you use a i2s.write() directly ?

[KiShiVi]

As far as I understand, this is not able to stop the receiver ring buffer. Wouldn't there be a situation where two sources would try to access i2s at once? Will there be a conflict?

[pschatzmann]

Currently you can call e.g. set_stream_reader(nullptr, flag); to update the i2s_output flag.
I have added the new method set_output_active(flag) to make it a bit more explicit...

[KiShiVi]

Thank you very much! I am very grateful for your prompt feedback!