How to play MemoryStream audio files on demand

[xXxOlivierxXx]

Hello everyone, sorry if this has been asked before, I checked the wiki but could not find any similar discussions.

After multiple tests attempting to play Audio files on the ESP32-S2 and ESP32-S3, i've had the most success with the arduino-audio-tools library, and managed to get the "streams-memory_raw-i2s" example working successfully over I2S with an max98357a amplifier, and was able to generate my own sample audio files and play them.

My next attempt is to get this audio file to play on demand, for instance, when I push a button, but I'm having problems with the right syntax for this. In the library example, most of the code is in the setup function, and void only does is:

void loop(){ if (!copier.copy()){ i2s.end(); stop(); } }

This is my code so far:

/**
 * @file streams-memory_raw-i2s.ino
 * @author Phil Schatzmann
 * @brief Compile with Partition Scheme Hughe APP!
 * @version 0.1
 * @date 2021-01-24
 * 
 * @copyright Copyright (c) 2021
 * 
 */

#include "AudioTools.h"
#include "1000.h"

#define I2S_LRC       18
#define I2S_BCLK      17
#define I2S_DOUT      9
const int buttonPin = 8;  // the number of the pushbutton pin
int buttonState = 0;  // variable for reading the pushbutton status

AudioInfo info(22050, 1, 16); //First number is the sample rate, second is number of channels (1 = mono), third is bits per sample
I2SStream i2s;  // Output to I2S
MemoryStream music(en1000_raw, en1000_raw_len);
StreamCopy copier(i2s, music); // copies sound into i2s

auto config = i2s.defaultConfig(TX_MODE);

void setup(){
    Serial.begin(115200);
    delay(2000);
    AudioLogger::instance().begin(Serial, AudioLogger::Info);   
    pinMode(buttonPin, INPUT);
    pinMode(LED_BUILTIN, OUTPUT);
}


void loop(){
    if (!copier.copy()){
      i2s.end();
      stop();
    }

checkButton();

}

void checkButton(){

  buttonState = digitalRead(buttonPin);

  // check if the pushbutton is pressed. If it is, the buttonState is HIGH:
  if (buttonState == HIGH) {
    // turn LED on:
    digitalWrite(LED_BUILTIN, HIGH);
    playAudio();
    
  } else {
    // turn LED off:
    digitalWrite(LED_BUILTIN, LOW);
  }
  
}

void playAudio(){

  music(en1000_raw, en1000_raw_len);
  copier(i2s, music); // copies sound into i2s

    config.copyFrom(info);
    config.pin_bck  = I2S_BCLK;
    config.pin_ws   = I2S_LRC;
    config.pin_data = I2S_DOUT;
    i2s.begin(config);  

}

I'm primarily having issues understanding how to instantiate and call the "MemoryStream music" and "StreamCopy copier" lines on demand, when I run this code I get:

.........\PlayAudioButtonPush\PlayAudioButtonPush.ino:66:8: error: no match for call to '(audio_tools::MemoryStream) (const unsigned char [53978], unsigned int&)'
66 | music(en1000_raw, en1000_raw_len);
| ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
.........\PlayAudioButtonPush.ino:67:9: error: no match for call to '(audio_tools::StreamCopy) (audio_tools::I2SStream&, audio_tools::MemoryStream&)'
67 | copier(i2s, music); // copies sound into i2s
| ~~~~~~^~~~~~~~~~~~

Any guidance will be greatly appreciated!

[pschatzmann]

I think the error messages are pretty speaking: this is not valid C++ syntax!

Please check the Class documentation for the methods that are available.
In addition your logic is completely flawed: if you press the butten, you will call playAudio() servarl thousend times per second as long as it is pressed!

I suggest that you read the second chapter in the Wiki or you google the topc how to debouce the input...

[xXxOlivierxXx]

Thanks for your answer. I have mostly experience with C# but not enough with C++ as you might have seen.
I'm ashamed to admit I had to get some help from Claude.AI but I finally got my test code to work:

/**
 * @file streams-memory_raw-i2s.ino
 * @author Phil Schatzmann
 * @brief Compile with Partition Scheme Hughe APP!
 * @version 0.1
 * @date 2021-01-24
 * 
 * @copyright Copyright (c) 2021
 */

#include "AudioTools.h"
#include "1000.h"

#define I2S_LRC       18
#define I2S_BCLK      17
#define I2S_DOUT      9
const int buttonPin = 8;  // the number of the pushbutton pin

// Button State Variables
int buttonState = 0;  // variable for reading the pushbutton status
bool buttonReleased = true; //if true means the button was already released and can be pressed again
bool isPlaying = false;  // track if audio is currently playing

// Audio Objects
AudioInfo info(22050, 1, 16); //First number is the sample rate, second is number of channels (1 = mono), third is bits per sample
I2SStream i2s;  // Output to I2S
MemoryStream* music = nullptr;
StreamCopy* copier = nullptr;

auto config = i2s.defaultConfig(TX_MODE);

void setup() {
    Serial.begin(115200);
    delay(2000);
    AudioLogger::instance().begin(Serial, AudioLogger::Info);   
    pinMode(buttonPin, INPUT);
    pinMode(LED_BUILTIN, OUTPUT);

    // Initial I2S configuration
   
    config.copyFrom(info);
    config.pin_bck = I2S_BCLK;
    config.pin_ws = I2S_LRC;
    config.pin_data = I2S_DOUT;
    i2s.begin(config);
}

void loop() {
    checkButton();
    
    if (isPlaying && copier != nullptr) {
        if (!copier->copy()) {
            stopAudio();
        }
    }
}

void checkButton() {
    buttonState = digitalRead(buttonPin);

    // check if the pushbutton is pressed. If it is, the buttonState is HIGH:
    if (buttonState == HIGH) {
        // turn LED on:
        digitalWrite(LED_BUILTIN, HIGH);
        
        if (buttonReleased && !isPlaying) {  // Only play if button was released and not currently playing
            buttonReleased = false;
            playAudio();
        }
    } else {
        // turn LED off:
        digitalWrite(LED_BUILTIN, LOW);
        buttonReleased = true;  // Button is released
    }
}

void playAudio() {
    // Clean up any existing objects
    stopAudio();
    
    // Create new audio objects
    music = new MemoryStream(en1000_raw, en1000_raw_len);
    copier = new StreamCopy(i2s, *music);
    isPlaying = true;
    i2s.begin(config);
}

void stopAudio() {
    isPlaying = false;
    
    if (copier != nullptr) {
        delete copier;
        copier = nullptr;
    }
    
    if (music != nullptr) {
        delete music;
        music = nullptr;
    }
    
    i2s.end();
}

WhatsApp.Video.2024-10-24.at.12.37.55.PM.mp4