How to properly use ICYStreamBufferedESP32?

[davidg5678]

Hi all,

I am building an internet radio with an ESP32-S3, and have run into an issue where the audio drops out for a fraction of a second. In the serial log, the dropouts manifest as:

[I] StreamCopy.h : 173 - StreamCopy::copy 167 -> 0 -> 0 bytes - in 0 hops [I] StreamCopy.h : 173 - StreamCopy::copy 167 -> 0 -> 0 bytes - in 0 hops [I] StreamCopy.h : 173 - StreamCopy::copy 167 -> 0 -> 0 bytes - in 0 hops

I believe using a buffered audio stream would help resolve this issue, as I read in the following discussion post: #432

When I attempt to use this kind of stream object however, I am provided with a large number of compiler errors. I think I'm misunderstanding how to properly use this object, and could really use some guidance!

Thank you for your help!

Here's my current code:

#include <AudioLogger.h>
#include <AudioTools.h>
#include <AudioToolsConfig.h>
#include "AudioTools/AudioCodecs/CodecMP3Helix.h"  // install https://github.com/pschatzmann/arduino-libhelix
#include <AudioTools/CoreAudio/AudioHttp/URLStreamESP32.h>
#include <AudioTools/CoreAudio/AudioHttp/URLStreamBufferedT.h>

#define URL_STREAM_BUFFER_COUNT 64  //use this to combat dropouts in the stream.

const char* ssid = "myssidgoeshere";
const char* pwd = "mypasswordgoeshere";
const char* streamURL = "http://stream.live.vc.bbcmedia.co.uk/bbc_world_service";

ICYStreamBufferedESP32 url(ssid, pwd);

I2SStream i2s;  // final output of decoded stream
MP3DecoderHelix codec;
EncodedAudioStream dec(&i2s, &codec);  // Decoding stream
StreamCopy copier(dec, url);           // copy url to decoder

// callback for meta data --Extract the metadata from the Icecast internet radio stream and print it to the serial console.
void printMetaData(MetaDataType type, const char* str, int len) {
  Serial.print("==> ");
  Serial.print(MetaDataTypeStr[type]);
  Serial.print(": ");
  Serial.println(str);
}

void setup() {
  Serial.begin(115200);
  AudioToolsLogger.begin(Serial, AudioToolsLogLevel::Info);
  Serial.println("ESP32 has restarted!");
  // setup i2s
  auto config = i2s.defaultConfig(TX_MODE);
  // Manually define the pins for the off-brand ESP32-S3.
  config.pin_bck = 5;
  config.pin_data = 14;
  config.pin_ws = 6;
  //config.mode = I2S_STD_FORMAT;
  i2s.begin(config);

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

  // mp3 radio
  url.setMetadataCallback(printMetaData);
  url.begin(streamURL, "audio/mp3");
}

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

Here are the errors I'm getting:

error: cannot declare variable 'url' to be of abstract type 'audio_tools::URLStreamBufferedT<audio_tools::ICYStreamT<audio_tools::URLStreamESP32> >'
   16 | ICYStreamBufferedESP32 url(ssid, pwd);
      |                        ^~~
In file included from /Users/me/Documents/Arduino/libraries/arduino-audio-tools/src/AudioTools/CoreAudio/AudioHttp/URLStream.h:17,
                 from /Users/me/Documents/Arduino/libraries/arduino-audio-tools/src/AudioTools/CoreAudio/AudioHttp/AudioHttp.h:8,
                 from /Users/me/Documents/Arduino/libraries/arduino-audio-tools/src/AudioTools/CoreAudio/AudioPlayer.h:5,
                 from /Users/me/Documents/Arduino/libraries/arduino-audio-tools/src/AudioTools/CoreAudio.h:18,
                 from /Users/me/Documents/Arduino/libraries/arduino-audio-tools/src/AudioTools.h:74,
                 from /private/var/folders/xw/flky0pj94qq8_44kp95ll_th0000gn/T/.arduinoIDE-unsaved2025627-15258-149goub.saue/sketch_jul27a/sketch_jul27a.ino:2:
/Users/me/Documents/Arduino/libraries/arduino-audio-tools/src/AudioTools/CoreAudio/AudioHttp/URLStreamBufferedT.h:154:7: note:   because the following virtual functions are pure within 'audio_tools::URLStreamBufferedT<audio_tools::ICYStreamT<audio_tools::URLStreamESP32> >':
  154 | class URLStreamBufferedT : public AbstractURLStream {
      |       ^~~~~~~~~~~~~~~~~~
In file included from /Users/me/Documents/Arduino/libraries/arduino-audio-tools/src/AudioTools/AudioCodecs/MultiDecoder.h:6,
                 from /Users/me/Documents/Arduino/libraries/arduino-audio-tools/src/AudioTools/AudioCodecs/AudioCodecs.h:28,
                 from /Users/me/Documents/Arduino/libraries/arduino-audio-tools/src/AudioTools/CoreAudio/AudioPlayer.h:3:
/Users/me/Documents/Arduino/libraries/arduino-audio-tools/src/AudioTools/CoreAudio/AudioHttp/AbstractURLStream.h:60:16: note:     'virtual void audio_tools::AbstractURLStream::setConnectionClose(bool)'
   60 |   virtual void setConnectionClose(bool flag) = 0;
      |                ^~~~~~~~~~~~~~~~~~
/Users/me/Documents/Arduino/libraries/arduino-audio-tools/src/AudioTools/CoreAudio/AudioHttp/AbstractURLStream.h:63:23: note:     'virtual const char* audio_tools::AbstractURLStream::urlStr()'
   63 |   virtual const char* urlStr() = 0;
      |                       ^~~~~~
/Users/me/Documents/Arduino/libraries/arduino-audio-tools/src/AudioTools/CoreAudio/AudioHttp/AbstractURLStream.h:66:18: note:     'virtual size_t audio_tools::AbstractURLStream::totalRead()'
   66 |   virtual size_t totalRead() = 0;
      |                  ^~~~~~~~~
/Users/me/Documents/Arduino/libraries/arduino-audio-tools/src/AudioTools/CoreAudio/AudioHttp/AbstractURLStream.h:69:15: note:     'virtual int audio_tools::AbstractURLStream::contentLength()'
   69 |   virtual int contentLength() = 0;
      |               ^~~~~~~~~~~~~
/Users/me/Documents/Arduino/libraries/arduino-audio-tools/src/AudioTools/CoreAudio/AudioHttp/AbstractURLStream.h:73:16: note:     'virtual bool audio_tools::AbstractURLStream::waitForData(int)'
   73 |   virtual bool waitForData(int timeout) = 0;
      |                ^~~~~~~~~~~
exit status 1

Compilation error: cannot declare variable 'url' to be of abstract type 'audio_tools::URLStreamBufferedT<audio_tools::ICYStreamT<audio_tools::URLStreamESP32> >'

[pschatzmann]

I committed some corrections.
If you have performance problems, try URLStream which should have a bit less overhead.
I am not sure how the ESP32 specific classes compare to the regular Arduino implementations...

[davidg5678]

Thanks so much for your help, Phil!

Using your corrections, my code now compiles as expected. Additionally, ICYStreamBufferedESP32 seems to have solved the choppy audio issues I'd been having. I'll have to experiment and see if I hear any difference between ICYStreamBufferedESP32 and ICYStreamBuffered.

Also, it's good to know that URLStream has better performance than ICYStream. If I don't end up putting a display on my internet radio, I don't think Icecast metadata will be terribly important to me.