Stream data in the moment we choose

[pablofr918]

Hello there!! First of all thank you for all your work, because this repository helped me a lot.

I wanted to know if it is possible to make the out->read(data, len) out of the callback function.
For example, I would make a a2dp_source.start("Beats_Pablo"), without calling the callback and then I think there is another function that makes the WriteData(Data). So is it possible to do this, creating a data variable to use in the WritData()?
(The data variable could be written with *out->read (Channels Data, size_t len) but out of the callback).

[pschatzmann]

I propose to switch to using Streams - this hides all the complexity around callbacks. Then you just read from the source A2DPStream and write to the Sink Stream - or you let the StreamCopy class do the copy… https://github.com/pschatzmann/arduino-audio-tools/tree/main/sandbox/streams-a2dp-serial

…

On 11 May 2021, at 08:16, pablofr918 ***@***.***> wrote: Hello there!! First of all thank you for all your work, because this repository helped me a lot. I wanted to know if it is possible to make the out->read(data, len) out of the callback function. For example, I would make a a2dp_source.start("Beats_Pablo"), without calling the callback and then I think there is another function that makes the WriteData(Data). So is it possible to do this, creating a data variable to use in the WritData()? (The data variable could be written with *out->read (Channels Data, size_t len) but out of the callback). — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub, or unsubscribe.

[pablofr918]

I will check it and tell you, thank you very much!

[pablofr918]

I'm not sure how it works, so what I think it could be the way is:

1. Create an out as: A2DPStream out::A2DPStream::instance();
2. The out in the setup() will be in TX mode as: in.begin(TX_MODE, "Beats_Pablo");
   But after this, I need to create the in from which I'll make the copy, that needs to be the mp3 stream. Thats the part I don't know how to do.
   I don't know if it has to be an A2DPStream class too or what.

[pschatzmann]

OK...you want to send an MP3 input to an A2DP sink:
Simplest way - do it like in the provided example https://github.com/pschatzmann/arduino-audio-tools/tree/main/basic-api/base-file_mp3-a2dp
My more complex way: Implement a MP3 Decoder class and share it with the community. I have an example for for processing a WAV file https://github.com/pschatzmann/arduino-audio-tools/tree/main/sandbox/streams-file_wav-I2S_external

[pablofr918]

Yes, I'm using the mp3-a2dp but the problem is that I would like to do a connexion to a sink without sending the data instantly, and then when I want to send it, make the mp3.begin and send. But that's what I'm stuck in.

[pschatzmann]

Why not just move the audio logic from the setup into the loop - but protect it from being executed by a boolean flag. When you want to start the playback set the flag to true and the setup will execute…

…

On 11 May 2021, at 09:17, pablofr918 ***@***.***> wrote: Yes, I'm using the mp3-a2dp but the problem is that I would like to do a connexion to a sink without sending the data instantly, and then when I want to send it, make the mp3.begin and send. But that's what I'm stuck in. — You are receiving this because you commented. Reply to this email directly, view it on GitHub, or unsubscribe.

[pablofr918]

Yes, that's what I was trying, but the thing is, if the callback isn't called anytime I want to play a different mp3 file, it will play the same, won't it? That was why I was trying to make it with a writeData() function.
The main goal is to connect, and then play different songs, first one, after a time, set the flag to true, but using another mp3 file. But if the callback isn't called, the data that will be sent is the one that read the first time, isn't it? But that is not possible I think.

[pschatzmann]

The callback will be automatically called after A2DP has been started. You just need to feed it with data. So at the end of your mp3 file move to the next and feed it with data by calling mp3->begin(file, out);
I think that should work....

[pablofr918]

I will try it, thank you very much for the support!

[pablofr918]

Hi again, I'm trying to do what you said, but doesn't work. What I'm doing is calling the start() and then when I want I send an MQTT message that makes the mp3->begin(file,out). The first time I do it it works, but if I want to do it again it crashes and does nothing. I would like to know how the get_sound_data works, so maybe I could do it using another way. For example, there is a function in BluetoothA2DPSource.h whichi is *bool writeData(SoundData data); and if I could convert my mp3 file to that data it would be easy to send via a2dp, do you know any way to get to this point?

[pschatzmann]

In order to simplify the usage I have added a simple AudioPlayer class ...
https://www.pschatzmann.ch/home/2021/10/11/a-simple-arduino-mp3-player/