When using Input mixer, how do I ensure a looped sound continues after additional sounds are finished?

[MJenkings]

I am using the input mixer function to mix 2 wav streams from an SD card, it works perfectly. However, one file is 2 seconds long and must loop indefinitely while another is about 30 secs long and only plays once. The problem I have is that, when the 30 second file is finished, the short file just stops. I want it to continue looping but cannot figure out how to do this. Any help would be appreciated.

[pschatzmann]

Just wrap the file in a FileLoop!
and use the file loop as data source.

[MJenkings]

Thanks for the assist. I have used the FileLoop as suggested but it still isn't looping indefinitely. The problem appears to be that when the longer file finishes, the ESP32-S3 just hangs hence why it isn't continuing the looping. Because it hangs, I get no error message. Only a hard power cycle brings it to life again.

This is the entire code in the sketch

#include "AudioTools.h"
#include "AudioLibs/AudioSourceSD.h"
#include "AudioLibs/AudioKit.h"
#include "Audiotools/AudioOutput.h"
#include "Audiotools/AudioIO.h"
#include "AudioLibs/FileLoop.h"
#include <SPI.h>
#include <SD.h>
#include "AudioCodecs/CodecWAV.h"

//config for sd card reader
#define SD_CS 5
#define SPI_MOSI 41
#define SPI_MISO 40
#define SPI_SCK 39

File audioFile1;

uint16_t sample_rate=44100;
InputMixer<int16_t> mixer;

I2SStream i2s; // final output of decoded stream
MultiOutput multi;
VolumeStream vol(i2s); // sets volume and passes audio to i2s
StreamCopy sfx(multi, mixer); // copies sound into vol & out from mixer (destination , source)
EncodedAudioStream decoder(&vol, new MP3DecoderHelix()); // Decoding stream

VolumeOutput out;

void printMetaData(MetaDataType type, const char* str, int len){
Serial.print("==> ");
Serial.print(toStr(type));
Serial.print(": ");
Serial.println(str);
}

FileLoop loopingFile;

void setup() {

Serial.begin(115200);
decoder.setNotifyAudioChange(i2s);
decoder.begin();
multi.add(vol);
multi.add(out);

AudioLogger::instance().begin(Serial, AudioLogger::Info);

// setup output

auto config = i2s.defaultConfig(TX_MODE);

config.pin_ws = 14;
config.pin_bck = 13;
config.pin_data = 11;
config.sample_rate = sample_rate ;
config.channels = 1;
i2s.begin(config);
out.begin(config);

SPI.begin(SPI_SCK, SPI_MISO, SPI_MOSI);

SD.begin(SD_CS);

vol.begin(config); // we need to provide the bits_per_sample and channels
vol.setVolume(0.2);

audioFile1 = SD.open("/audio/theme.wav");

loopingFile.setFile(SD.open("/audio/scanner.wav"));
loopingFile.setLoopCount(-1); // define loop count
loopingFile.begin();

mixer.add(audioFile1,25); //theme
mixer.add(loopingFile,75);
mixer.begin(config);

}

void loop() {
sfx.copy();
Serial.print("Volume: ");
Serial.println(out.volume());

}

[pschatzmann]

Wouln't you need to wrap both files if you want to play endlessly ?

[MJenkings]

I only want one file to play on loop and the other to play one time. This works at the start, with the longer file (audioFile1) playing once while the other loops. However, once the longer file has finished playing once, everything stops and the ESP32 hangs.

[pschatzmann]

On the mixer try to call setLimitToAvailableData(true)

[MJenkings]

Good news; it fixed the hanging issue. The ESP32 no longer hangs. However, both audio streams stop when the longer one comes to an end. The looping one still doesn't continue to loop.

[pschatzmann]

This is up to you now: You need to remove the ended input out of the mixer or just stop using the mixer if you want to continue with the output of the loop

[MJenkings]

Ok that sounds like it will do what I need then. Fantastic. One final question. How can I tell if the steam on a channel has come to the end of the file? For a non-looping sound, it would be useful to detect when the sound has finished playing.

[pschatzmann]

Usually just calling available() on the stream will tell you if there is still more data

[MJenkings]

I did try that in the mixer.available() and the Stream it feeds the mixer to, but they just continue to return a value of 1024 even after the mixer streams had ended.

[pschatzmann]

For loopingFile I would expect this (since it is endless), but not for audioFile1: there I would expect that you should get the remaining bytes and 0 when it is at the end.

Alternatively you can get the file position and compare it with the file size.

[MJenkings]

Thank you, I have now resolved all this issues with this. It's all working perfectly.