Why WAV is not recordered to 8 bits sample resolution?

[hash6iron]

Hi @pschatzmann.

This below is my sketch. I don't achieve to WAV recording at 8-bits samples resolution. The audio is output to kitstrem (speaker) and wav file when WAV_8BIT_MONO=false, but nothing is recordered to file when WAV_8BIT_MONO=true (but yes to output speaker)
What is wrong?
Thanks in advance.

bool WAV_8BIT_MONO = true;

size_t wavfilesize = 0;
auto new_sr = kitStream.defaultConfig(RXTX_MODE);

const size_t BUFFER_SIZE = 4096;
int16_t buffer[BUFFER_SIZE];

EncodedAudioStream encoder(&wavfile, new WAVEncoder());       
NumberFormatConverterStreamT<int16_t, uint8_t> nfc(encoder); 

MultiOutput multi(kitStream);

if (WAV_8BIT_MONO) 
{
  hmi.writeString("tape.wavind.txt=\"WAV8\"");
  multi.add(nfc);
}
else
{
  multi.add(encoder);
}

multi.begin();

StreamCopy copier(multi, kitStream); // copies data to both file and line_out
copier.setSynchAudioInfo(true);

auto ecfg = encoder.defaultConfig();

if (WAV_8BIT_MONO)
{
  ecfg.sample_rate = DEFAULT_8BIT_WAV_SAMPLING_RATE_REC;
  ecfg.channels = 1; // Mono
  encoder.begin(ecfg);
  nfc.begin();
}
else
{
  ecfg.sample_rate = DEFAULT_WAV_SAMPLING_RATE_REC;
  ecfg.bits_per_sample = 16; 
  ecfg.channels = 2; // Stereo
  encoder.begin(ecfg);
}

copier.begin();

// loop de grabacion
while (!STOP)
{
    wavfilesize += copier.copy();        
}

Serial.write("File size: " + String(wavfilesize/1024) + " KB");

copier.end();
encoder.end();
multi.end();
wavfile.flush();
wavfile.close();

[pschatzmann]

You can't apply a NumberFormatConverterStreamT on a EncodedAudioStream: This is also converting non audio data like the header and will thus distroy it.

Apply the conversion on the source!

[hash6iron]

@pschatzmann ok,

I had those changes. The sketch now is as below, but nothing was recorded with WAV_8BIT_MONO=true (but WAV_8BIT_MONO=false was ok)

Any idea?
Thanks in advance.

  bool WAV_8BIT_MONO = true;
  
  size_t wavfilesize = 0;
  void WavRecording()

  auto new_sr = kitStream.defaultConfig(RXTX_MODE);
  kitStream.setAudioInfo(new_sr);       
  
  EncodedAudioStream encoder(&wavfile, new WAVEncoder());         
  NumberFormatConverterStreamT<int16_t, uint8_t> nfc(kitStream);  

  MultiOutput multi(kitStream);
  StreamCopy copier;
  multi.add(encoder);

  // to ear the input
  multi.add(kitStream);
  // Starting multi
  multi.begin();
    
  copier.setSynchAudioInfo(true);

  // Agregamos las salidas al multiple
  auto ecfg = encoder.defaultConfig();

  if (WAV_8BIT_MONO)
  {
    ecfg.sample_rate = 22050;
    //ecfg.bits_per_sample = 16; 
    ecfg.channels = 1; // Mono
    nfc.begin();
  }
  else
  {
    ecfg.sample_rate = 44100;
    ecfg.bits_per_sample = 16; 
    ecfg.channels = 2; // Stereo
  }

  encoder.begin(ecfg);

  if (WAV_8BIT_MONO) 
  {
    copier.begin(encoder,nfc);
  }
  else
  {
    copier.begin(encoder,kitStream);
  }

  while (!STOP)
  {
    wavfilesize += copier.copy();        
  }

  logln("Recording finish!");

  copier.end();
  encoder.end();
  multi.end();

  if (WAV_8BIT_MONO) nfc.end();

  wavfile.flush();
  wavfile.close();

}