another pure data question

[KatePimbleton]

Hello,

I'm using arduino-audio-tools ( cloned with git )
and an esp32-audio-kit

i'm trying to merge 2 mono FileLoops, copy the stereo stream to puredata, and output from pd to I2S.
It seems to work, kind of, the sound stutters ( a bit in the same way as when LOG is left to Info or Debug )
I tried to use a bigger buffer for stream copy but if it is set to 1024 my audiokit keeps rebooting.

the puredata patch used is the same as in the stream example, 2 in 2 outs, nothing else.

Am I exceeding the audiokit or sdcard capabilities ?

here's the code I came up with:

#include <SPI.h>
#include <SD.h>
#include "AudioTools.h"
#include "AudioLibs/AudioBoardStream.h"
#include "AudioLibs/FileLoop.h"
#include "Heavy_fileLoopPd.hpp"
#include "AudioLibs/PureDataStream.h"

const int chipSelect = PIN_AUDIO_KIT_SD_CARD_CS;

AudioInfo info(44100, 2, 16);
InputMerge<int16_t> merge;
Heavy_fileLoopPd pd_test(44100);
PureDataStream pd(pd_test);

AudioBoardStream i2s(AudioKitEs8388V1);  // final output of decoded stream
FileLoop loopingFile;
FileLoop loopingFile2;
EncodedAudioStream decoder(&loopingFile, new WAVDecoder());
EncodedAudioStream decoder2(&loopingFile2, new WAVDecoder());
StreamCopy copierToPd(pd, merge,256);
StreamCopy copierFromPd(i2s, pd,256);


void setup() {
  Serial.begin(115200);
  AudioLogger::instance().begin(Serial, AudioLogger::Warning);
  auto config = i2s.defaultConfig(TX_MODE);
  config.copyFrom(info);
  config.sd_active = true;
  i2s.begin(config);
  SD.begin(chipSelect);
  loopingFile.setFile(SD.open("/seanMono.wav"));
  loopingFile2.setFile(SD.open("/pianoMono.wav"));
  loopingFile.begin();
  loopingFile2.begin();
  merge.add(loopingFile);
  merge.add(loopingFile2);
  merge.begin(info);
  decoder.begin();
  decoder2.begin();
  pd.begin();
}
void loop() {
  copierToPd.copy();
  copierFromPd.copy();
}

[pschatzmann]

Difficult to say: I suggest that you try to test the different pieces separately before you integrate them into PD: e.g. input only & copy to i2s, input merge & copy to I2S

A couple of additional thoughts:

• you can try to lower the sample rate
• try to upgrade the AudioTools library: I don't know if you have the FileLoop implementation already which removes the WAV header automatically when moving back to the beginning. You can compare your local version with the actual implementation. Or call setStartPos(44) to ignore the header.

[KatePimbleton]

Cheers, I lowered the sample rate by half (22050hz), and it works fine.
I also tried bypassing Puredata, it works fine at 44100hz.
Maybe I could increase buffers, I did it in AudioConfig.h but
without exactly knowing what I do and with no luck.
How do I increase the buffers ?

[pschatzmann]

• Make sure that the log level is set to warning.
• In the constructor of the PureDataStream you can indicate the max buffer size: Currently this is 2K which is a bit too high and should better match with the copy size.
• In the constructor of the copier you can indicate how many bytes should be copied with each loop step. Try to increase the number. I think you might then also need to increase the stack size.
• The other place where you could play with is the i2s configuration in the sketch by setting the cfg.buffer_size and cfg.buffer_count.

[KatePimbleton]

cheers!

[pschatzmann]

I changed the PureDataStream to avoid any arrays on the stack. With the updated version it should be possible to increase the copy size e.g. to 1024