Looping on Files

[pschatzmann]

So far it has been easy to loop over memory based streams by just setting setLoop(true). For files, I am relying on the different file implementations that are provided by different libraries. Nevertheless, I decided to provide a new FileLoop or the more generic FileLoopT classes. These classes have quite a few options:

• You can define the loop count
• You can define the total size in bytes to be provided
• You can request to be notified about each rewind

Here is the example sketch that is endlessly playing the same file:

#include <SPI.h>
#include <SD.h>
#include "AudioTools.h"
#include "AudioLibs/AudioKit.h"
#include "AudioLibs/FileLoop.h"
#include "AudioCodecs/CodecMP3Helix.h"

const int chipSelect=PIN_AUDIO_KIT_SD_CARD_CS;
AudioKitStream i2s; // final output of decoded stream
EncodedAudioStream decoder(&i2s, new MP3DecoderHelix()); // Decoding stream
FileLoop loopingFile;
StreamCopy copier(decoder, loopingFile); 

void setup(){
  Serial.begin(115200);
  AudioLogger::instance().begin(Serial, AudioLogger::Info);  

  // setup audiokit before SD!
  auto config = i2s.defaultConfig(TX_MODE);
  config.sd_active = true;
  i2s.begin(config);

  // setup file
  SD.begin(chipSelect);
  loopingFile.setFile(SD.open("/ZZ Top/Unknown Album/Lowrider.mp3"));
  //loopingFile.setLoopCount(-1); // define loop count
  //audioFile.setStartPos(44); // restart from pos 44 for wav files
  //if ((audioFile.size()-44) % 1024!=0) audioFile.setSize((((audioFile.size()-44)/1024)+1)*1024+44);

  // setup I2S based on sampling rate provided by decoder
  decoder.begin();
}

void loop(){
  copier.copy();
}