Converting on the output side issue

[alw1746]

Hardware: Waveshare ESP32-S3-Zero
Software: ESP32S3 Module, Audio Tools 1.2.0, Arduino 2.3.6

I ran the 32-to-16bit conversion example shown on wiki,

https://github.com/pschatzmann/arduino-audio-tools/wiki/Converting-the-Data-Format

but the output is all 0,0. I modified the sketch to run for 800ms to read the output and saw this error line at startup:

[E] AudioStreamsConverter.h : 161 - toChannels is 0

Could this somehow be causing the issue of the 0,0? I expected to see a 16-bit plot on the Serial plotter but obviously nothing came out. I did try setting all 16-bit parameters to 32 and the plot works fine(despite the error line).

Sketch

#include "AudioTools.h"

SineWaveGenerator<int32_t> sine_wave;                   // subclass of SoundGenerator with max amplitude of 32000
GeneratedSoundStream<int32_t> in_stream(sine_wave);     // Stream generated from sine wave
CsvOutput<int16_t> out(Serial);                         // Output to Serial
AudioInfo from(44100, 2, 32);                                           
AudioInfo to(44100, 2, 16);                                           
FormatConverterStream conv(out);
StreamCopy copier(conv, in_stream);                     // copies sound to out

unsigned long timer1=0;            //loop timer
unsigned int period1 = 800;       //elapsed time(ms)
bool timer1Enabled=true;          //set false to disable timer
bool run=true;

void setup()
{
  Serial.begin(115200);
  delay(2000);            //needed for ESP32-S3
  AudioLogger::instance().begin(Serial, AudioLogger::Info);  

  sine_wave.begin(from, N_B4);
  in_stream.begin(from);
  conv.begin(from, to);

  out.begin(to);
}

void loop(){
  if (run) {
    copier.copy();
  }
  if ((millis() - timer1 > period1) && timer1Enabled) {       //heartbeat timer expired?
    timer1 = millis();                                        //reset HB timer expiry
    timer1Enabled=false;
    run=false;    //stop after period1 elapsed.
  }
}

Serial monitor output

[I] SoundGenerator.h : 165 - SineWaveGenerator::begin(channels=2, sample_rate=44100, frequency=493.88)
[I] SoundGenerator.h : 150 - bool audio_tools::SineWaveGenerator<T>::begin() [with T = long int]
[I] AudioTypes.h : 126 - SoundGenerator: sample_rate: 44100 / channels: 2 / bits_per_sample: 32
[I] Buffers.h : 418 - resize: 8
[I] SoundGenerator.h : 194 - setFrequency: 493.88
[I] SoundGenerator.h : 195 - active: true
[I] SoundGenerator.h : 157 - SineWaveGenerator::begin(channels=2, sample_rate=44100)
[I] SoundGenerator.h : 150 - bool audio_tools::SineWaveGenerator<T>::begin() [with T = long int]
[I] AudioTypes.h : 126 - SoundGenerator: sample_rate: 44100 / channels: 2 / bits_per_sample: 32
[I] AudioStreamsConverter.h : 790 - virtual void audio_tools::FormatConverterStream::setAudioInfo(audio_tools::AudioInfo)
[I] AudioTypes.h : 126 - FormatConverterStream sample_rate: 44100 / channels: 2 / bits_per_sample: 32
[I] AudioTypes.h : 126 - in: sample_rate: 44100 / channels: 2 / bits_per_sample: 32
[I] AudioTypes.h : 126 - out: sample_rate: 44100 / channels: 2 / bits_per_sample: 16
[I] AudioOutput.h : 165 - void audio_tools::CsvOutput<T>::setAudioInfo(audio_tools::AudioInfo) [with T = short int]
[I] AudioTypes.h : 126 -  sample_rate: 44100 / channels: 2 / bits_per_sample: 16
[E] AudioStreamsConverter.h : 161 - toChannels is 0
[I] AudioStreamsConverter.h : 168 - --> ChannelFormatConverterStream
[I] AudioTypes.h : 126 - in: sample_rate: 44100 / channels: 2 / bits_per_sample: 32
[I] AudioTypes.h : 126 - out: sample_rate: 44100 / channels: 2 / bits_per_sample: 32
[I] AudioStreamsConverter.h : 471 - -> NumberFormatConverterStream:
[I] AudioTypes.h : 126 - in: sample_rate: 44100 / channels: 2 / bits_per_sample: 32
[I] AudioStreamsConverter.h : 170 - begin 2 -> 2 channels
[I] AudioStreamsConverter.h : 24 - begin 2 -> 2 channels
[I] AudioStreamsConverter.h : 508 - begin 32 -> 16 bits
[I] ResampleStream.h : 64 - begin step_size: 1.000000
[I] ResampleStream.h : 145 - setStepSize: 1.000000
[I] ResampleStream.h : 145 - setStepSize: 1.000000
[I] ResampleStream.h : 129 - -> ResampleStream:
[I] AudioTypes.h : 126 - out: sample_rate: 44100 / channels: 2 / bits_per_sample: 16
[I] AudioOutput.h : 165 - void audio_tools::CsvOutput<T>::setAudioInfo(audio_tools::AudioInfo) [with T = short int]
[I] AudioTypes.h : 126 -  sample_rate: 44100 / channels: 2 / bits_per_sample: 16
0,0
: <42 lines of 0,0>
0,0
[I] StreamCopy.h : 176 - StreamCopy::copy  1024 -> 1024 -> 1024 bytes - in 1 hops

[pschatzmann]

I committed a correction. Alternatively you can try with conv.setBuffered(false);

Usually I recommend to use the NumberFormatConverterStream when you just want to change the bits_per_sample, but in this case the issue was in the NumberFormatConverterStream itself.