How to play multiple WAV-Files or MP3 files (want to build a Drum Module

[basementmedia2]

Hi,

How can you play several mp3s or wav-files SIMULTANEOUSLY with you library?
I found this example:

/**

• @file streams-generator_inputmixer-audiokit.ino
• @brief Tesing input mixer
• @author Phil Schatzmann
• @copyright GPLv3
  */

#include "AudioTools.h"
#include "AudioTools/AudioLibs/AudioBoardStream.h"

AudioInfo info(32000, 2, 16);
SineWaveGenerator<int16_t> sineWave1(32000); // subclass of SoundGenerator with max amplitude of 32000
SineWaveGenerator<int16_t> sineWave2(32000); // subclass of SoundGenerator with max amplitude of 32000
GeneratedSoundStream<int16_t> sound1(sineWave1); // Stream generated from sine wave
GeneratedSoundStream<int16_t> sound2(sineWave2); // Stream generated from sine wave
InputMixer<int16_t> mixer;
AudioBoardStream out(AudioKitEs8388V1);
StreamCopy copier(out, mixer); // copies sound into i2s

// Arduino Setup
void setup(void) {
// Open Serial
Serial.begin(115200);
AudioToolsLogger.begin(Serial, AudioToolsLogLevel::Info);

// start I2S
Serial.println("starting I2S...");
auto config = out.defaultConfig(TX_MODE);
config.copyFrom(info);
out.begin(config);

// Setup sine wave
sineWave1.begin(info, N_B4);
sineWave2.begin(info, N_E4);

mixer.add(sound1);
mixer.add(sound2);
mixer.begin(info);

Serial.println("started...");
}

// Arduino loop - copy sound to out
void loop() {
copier.copy();
}

But as i am a beginner in coding, i am not able to change the code in a way, that MP3s are played instead of the SINE-WAVES.

I hope this is the last question i have to ask you.
As you helped me perfectly on my last questions my project (a MIDI drum module for connection of Drum-Pads) is nearly finished now :-)

[pschatzmann]

Please read the Wiki about Codecs and the one about Mixing and Merging Audio!
If your files have a different AudioInfo (e.g. sample rate) you will also need to read the Wiki about Changing the Format!

I suggest that you keep things simple and stick with WAV files.
With MP3 you will run into all sorts of problems if you try this...

[basementmedia2]

Hey Phil,

i have searched the wiki for "merging audio" but i find only this:

https://github.com/pschatzmann/arduino-audio-tools/wiki/Splitting-and-Merging-Audio
--> In this link i find only examples that explain how to mix sinus-waves but not MP3 or Wavs

What i want to do is the following:

I have connected a MIDI-IN circuit to the ESP32 Audiokit Board and assigned WAV-Samples to incoming MIDI-Notes of a electronic drumkit. E.g. if Note C2 is coming --> playback of "Bassdrum.wav" should be started, if Note D2 is coming --> playback of "Snaredrum.wav" should be started and so on.

At the moment i do something like that (simplified example) which works in principle:

if (midiSerial.available() >= 3) {
      byte statusByte = midiSerial.read();
      byte command = statusByte & 0xF0;
      
      byte note = midiSerial.read();
      byte velocity = midiSerial.read();

      note_pressed = getNoteName(note);
      note_pressed_val = note;

      // Zuweisung der Note zu einem Sample aus SPIFFS laden
      NoteConfig config = loadNoteConfig(note);

      if (command == 0x90 && velocity > 0) {
        if (config.filename != "") {
          playSampleByName(config.filename);
        }
      } 

  }

But Problem is, that when playback of a new sample is started, the playback of currently running sample is stopped.
But as i want to be able to play multiple drum-parts simultaneously, new "players" must be created on the fly depending on the incoming Midi-Notes (respectively new samples must be "merged" or "mixed" to the already playing samples but the already playing samples must not be restarted when a new sample playback is started. Means when a cymbal-Sample is started and directly after that the bassdrum-sample is started the rest of the cymbal should be played simultaneously.

Is this possible with your library and do you have an example for me?

Best regards
Daniel

[pschatzmann]

I never tried something like this, so I don't know into what probems you might run.

From a conceptual point of view there is not differerence if you process a GeneratedSoundStream like in the example or an EncodedAudioStream: You can replace data source from the example with any other!

I guess the only complexity is the housekeeping that needs to be done to remove completed files in your sketch.

ps. I added some more methods that should support you in the housekeeping...

[basementmedia2]

I think i am not able to transfer the sinus-example to my case (wav-files) :-(

Maybe you want to do a good deed today and give me even more support :-)

First question i am not able to answer is:
Do I need the input mixer example as starting point or the output mixer example?
I guess the input mixer, correct?
If yes, how do i have to declare the wav-sources?

/**
 * @file streams-generator_inputmixer-audiokit.ino
 * @brief Tesing input mixer
 * @author Phil Schatzmann
 * @copyright GPLv3
 */
 
#include "AudioTools.h"
#include "AudioTools/AudioLibs/AudioBoardStream.h"

AudioInfo info(32000, 2, 16);

InputMixer<int16_t> mixer;
AudioSourceSD source(startFilePath, ext, PIN_AUDIO_KIT_SD_CARD_CS);
AudioBoardStream kit(AudioKitEs8388V1);
WAVDecoder decoder; 
AudioPlayer player(source, kit, decoder);

StreamCopy copier(out, mixer);

// Arduino Setup
void setup(void) {  
  // Open Serial 
  Serial.begin(115200);
  AudioToolsLogger.begin(Serial, AudioToolsLogLevel::Info);

  // start I2S
  Serial.println("starting I2S...");
  auto config = out.defaultConfig(TX_MODE);
  config.copyFrom(info); 
  out.begin(config);


  mixer.add(player.setPath("/pathtowavfile1")); // This way??
  mixer.add(player.setPath("/pathtowavfile2")); // This way??
  mixer.begin(info);

  Serial.println("started...");
}

// Arduino loop - copy sound to out 
void loop() {
  copier.copy();
}

Sorry... maybe this project is a little bit to complex for me, but i want to try it anyway.
I have seen youtube videos of persons that made piano-moduls using the ESP32 Audiokit so i think in principle it should be possible to also make a drum-sampler...

[pschatzmann]

• Both should work
• The second question I have already aswered serveral times with
  • read the Wiki about Codecs
  • EncodedAudioStream