popping issues while stopping and starting playback and when switching streams

[techexplorers123]

hi,
i manage to build a good code and it works fine
but, there seams to be a popping issue while pausing or starting playback as well as while trying to play other sounds for audio feedback of the status of speacker.
here is a small recording showing this problem: https://next.techclub.co.in/s/EaZ2dHaYkyK2YQg
i am using the internal DAC of the esp32 connected to a class d 15w AMP.
note: try to play both sounds at the same time, but that doesn't go well.
try to use mixer as well but got no where with that as i can't figure out how to add that to this code.
wish there is a better newbie docs for those.
here is my code:

#include "AudioTools.h"
#include "BluetoothA2DPSink.h"
#include "SPIFFS.h"

AnalogAudioStream analogOut;
NullStream noth;
BluetoothA2DPOutputAudioTools btOutput;
BluetoothA2DPSink a2dp_sink(btOutput);
EncodedAudioStream decoder(&analogOut, new WAVDecoder());
WAVDecoder wavDec;
void playEventSound(const String &filename)
{
  AudioInfo c_info = analogOut.audioInfo();
  btOutput.set_output(noth);
  decoder.begin();
  File f = SPIFFS.open(filename);
  StreamCopy copier(decoder, f);
  copier.copyAll();
  f.close();
  decoder.end();
  analogOut.setAudioInfo(c_info);
  btOutput.set_output(analogOut);
}

void on_connection_state_changed(esp_a2d_connection_state_t state, void *ptr)
{
  if (state == ESP_A2D_CONNECTION_STATE_CONNECTED)
  {
    playEventSound("/connect.wav");
  }
  else if (state == ESP_A2D_CONNECTION_STATE_DISCONNECTED)
  {
    playEventSound("/disconnect.wav");
  }
}

void setup()
{
  SPIFFS.begin();
  auto cfg = analogOut.defaultConfig();
  analogOut.begin(cfg);
  a2dp_sink.set_on_connection_state_changed(on_connection_state_changed);
  a2dp_sink.set_auto_reconnect(true, 10);
  a2dp_sink.set_volume(150);
  a2dp_sink.set_mono_downmix(true);
  playEventSound("/poweron.wav");
  a2dp_sink.start("esp32");
}

void loop()
{
}

[pschatzmann]

Did you try my proposed solution with the A2DPStream ? So I suggest you try the easy solution first before digging into the complicated ones...

[techexplorers123]

hi,
i fixed that playback issue, But can't figure out how to handle the pop sounds.
decided to create new post since i didn't get any reply on the previous one.
hope you could help me with this.
sorry for the trouble, i am new to this so i only have limited understanding of how this works
i try to see if there is other projects that try to do what i am trying, but got nothing.

[pschatzmann]

My original answer still stands....

[techexplorers123]

Can you explain to me how would I approach this? I can't figure it out myself using a2dp stream like you said.
Thanks for the help.

[pschatzmann]

Just look at the examples that start with streams-a2dp and replace the audio sink

[techexplorers123]

hi,
tried to use the a2dpstream. The popping is gone but a new issue came up.
the wav playback works but the PC audio sounds strange.
here is a recording: https://next.techclub.co.in/s/Yq6LQLZyWMb5zxz
so, to solve that, i thought it might be the audio info so i copied the audio info before starting decoder and applied it back after ending the playback.
then the WAV file sounds strange but the PC audio sounds fine.
here is a recording: https://next.techclub.co.in/s/222NdP5NXjnDyzJ
thanks for the help.
code:

#include "AudioTools.h"
#include "SPIFFS.h"
#include "AudioTools/AudioLibs/A2DPStream.h"

AnalogAudioStream out;
A2DPStream a2dpStream;
EncodedAudioStream decoder(&out, new WAVDecoder());
File f;
StreamCopy *stat_copy = nullptr;
bool eff_play = false;
StreamCopy copier1(out, a2dpStream);
AudioInfo c_info;
void playEventSound(const String &filename) {
  if (!SPIFFS.exists(filename))
    return;
  // backup audio info before change
  c_info = out.audioInfo();
  eff_play = true;
  f = SPIFFS.open(filename, "r");
  decoder.begin(c_info);
  stat_copy = new StreamCopy(decoder, f);
}

void on_connection_state_changed(esp_a2d_connection_state_t state, void *ptr) {
  if (state == ESP_A2D_CONNECTION_STATE_CONNECTED) {
    playEventSound("/connect.wav");
  } else if (state == ESP_A2D_CONNECTION_STATE_DISCONNECTED) {
    playEventSound("/disconnect.wav");
  }
}

void setup() {
  SPIFFS.begin();
  auto btconf = a2dpStream.defaultConfig(RX_MODE);
  btconf.auto_reconnect = true;
  btconf.name = "esp32 player";
  btconf.silence_on_nodata = true;
  a2dpStream.begin(btconf);
  auto cfg = out.defaultConfig(TX_MODE);
  cfg.copyFrom(a2dpStream.audioInfo());
  out.begin(cfg);
  playEventSound("/poweron.wav");
}

void loop() {
  if (!eff_play) {
    copier1.copy();
  } else {
    if (stat_copy && f) {
      if (stat_copy->copy() == 0) {
        decoder.end();
        f.close();
        delete stat_copy;
        stat_copy = nullptr;
        eff_play = false;
      }
    }
    // reset audio info back
    out.setAudioInfo(c_info);
  }
}

[techexplorers123]

You think it'll be an easy thing to add?
Even the cheapest Bluetooth speaker you could find sold on the street have it and works great for crying out loud.
I've been at it for days now and still no progress.

[pschatzmann]

I think you should clean up your sketch first: this is very difficult to follow:

• dont use new and just define a global StreamCopy stat_copy(decoder, file); or define it a local object along the file in playEventSound
• in the playEventSound() then just do a stat_copy.copyAll() to play the whole file

You might have a missunderstanding with the decoder.begin(c_info); The WAV decoder contains already the audio info and will notify the output defined in EncodedAudioStream() about any changes. The best thing however would be to provide audio files with the same sample rate, channels and bits per sample, so that no changes are necessary: Double check in the info log what is happening. If you want to restore the settings for A2DP, the best thing is to get them from the A2DPStream.

I think in the AnalogAudioStream changing the audio info will shut down the DAC and restart it again with the new info. I am not sure if this is audible.

Finally I would recommend to use AnalogAudioStream only for testing. For a production applicatioin I definitly recommend a proper I2S DAC..

Finally I recommend to follow these instructions when building and testing a sketch!

[techexplorers123]

hi,
yeah, that seams to be the case. it seam to pop when the decoder is started and stopped and when the c_info is set.
the audio files are 44100, 16 bits, 2 channel output
it seams like the a2dp stream is the same.
however if i didn't copy the info before starting WAV playback and restore it afterwards, the audio sounds very low pitched and bad.
the opposite effect happens if i force the decoder to output with the info from the out before starting decoder. It comes out as high pitched audio.
no idea what is causing it or fixes for it without introducing pops by letting it switch the info and switching it back from the copy made once the streaming is done.
here is the new code, I've made some changes as you suggested.
it works just like the old code with the bluetooth a2dp but now doesn't need an extra nullstream to mute a2dp.
Also, is it possible to lower the volume of bluetooth and play some audio and bring it back up?
haven't found a way to do it.
thanks for the help. Even if i didn't get it working yet, learned a bunch of stuff at least.

#include "AudioTools.h"
#include "SPIFFS.h"
#include "AudioTools/AudioLibs/A2DPStream.h"
bool l_state, state, eff_play = false;
AnalogAudioStream out;
A2DPStream a2dpStream;
EncodedAudioStream decoder(&out, new WAVDecoder());
File f;
StreamCopy stat_copy(decoder, f);
StreamCopy copier1(out, a2dpStream);
AudioInfo c_info;
void playEventSound(const String &filename)
{
  if (!SPIFFS.exists(filename))
    return;
  c_info = out.audioInfo();
  eff_play = true;
  f = SPIFFS.open(filename, "r");
  decoder.begin();
}

void setup()
{
  SPIFFS.begin();
  auto cfg = out.defaultConfig(TX_MODE);
  cfg.copyFrom(a2dpStream.audioInfo());
  cfg.channels = 1;
  out.begin(cfg);
  auto btconf = a2dpStream.defaultConfig(RX_MODE);
  btconf.auto_reconnect = true;
  btconf.name = "esp32 player";
  btconf.silence_on_nodata = true;
  a2dpStream.begin(btconf);
  playEventSound("/poweron.wav");
}

void loop()
{
  if (!eff_play)
  {
    copier1.copy();
  }
  else
  {
    stat_copy.copyAll();
    decoder.end();
    out.setAudioInfo(c_info);
    eff_play = false;
  }
  state = a2dpStream.isConnected();
  if (state != l_state)
  {
    if (state)
    {
      playEventSound("/connect.wav");
    }
    else
    {
      playEventSound("/disconnect.wav");
    }
    l_state = state;
  }
}

[pschatzmann]

I would expect that your forcing the channel to 1 might be problematic.
Here is a better structured code: I would be surprised if this has your issue..

#include "AudioTools.h"
#include "SPIFFS.h"
#include "AudioTools/AudioLibs/A2DPStream.h"

AnalogAudioStream out;
A2DPStream a2dpStream;
StreamCopy copier(out, a2dpStream);

// for esp_a2d_connection_state_t see https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-reference/bluetooth/esp_a2dp.html#_CPPv426esp_a2d_connection_state_t
void connection_state_changed(esp_a2d_connection_state_t state, void *ptr) {
  switch (state) {
    case ESP_A2D_CONNECTION_STATE_CONNECTED:
      playEventSound("/connect.wav");
      break;
    case ESP_A2D_CONNECTION_STATE_DISCONNECTED:
      playEventSound("/disconnect.wav");
      break;
  }
}

void playEventSound(const String &filename) {
  File f = SPIFFS.open(filename, "r");
  if (!f) return;
  // play file
  WAVDecoder wav;
  EncodedAudioStream decoder(&out, &wav);
  decoder.begin();
  StreamCopy stat_copy(decoder, f);
  stat_copy.copyAll();

  // restore audio info from a2dp
  out.setAudioInfo(a2dpStream.audioInfo());
}

void setup() {
  AudioToolsLogger.begin(Serial, AudioToolsLogLevel::Info);

  SPIFFS.begin();
  auto cfg = out.defaultConfig(TX_MODE);
  out.begin(cfg);

  playEventSound("/poweron.wav");

  auto btconf = a2dpStream.defaultConfig(RX_MODE);
  btconf.auto_reconnect = true;
  btconf.name = "esp32 player";
  // btconf.silence_on_nodata = true;  // I don't think this is needed
  a2dpStream.begin(btconf);

  // register connection state callback
  a2dpStream.sink().set_on_connection_state_changed(connection_state_changed);

  // wait for connection
  while (!a2dpStream.isConnected())
    delay(100);
}

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

[techexplorers123]

hi,
It seams to be fixed. thanks a lot.
I'd see if i can pick up a DAC for better audio. The audio from the internal DAC is surprisingly good on this board though.
i have to change up the code you send a little bit though. I added decodor.begin () on setup and made the declaration of them global.
otherwise, the audio doesn't play.
also, somehow, the connection detection you did seams to be not working as it doesn't trigger playback of the wav file. so i switched to the one on the previous code i send.
again, thanks for the help.
here is my new code if anyone needs it.

#include "AudioTools.h"
#include "SPIFFS.h"
#include "AudioTools/AudioLibs/A2DPStream.h"

// the other one is not working, so switched to the old one
bool state, l_state;
AnalogAudioStream out;

A2DPStream a2dpStream;
StreamCopy copier(out, a2dpStream);

// brought them here so i can call begin for decoder  on setup. otherwise, not working
WAVDecoder wav;
EncodedAudioStream decoder(&out, &wav);

void playEventSound(const String &filename)
{
  File f = SPIFFS.open(filename, "r");
  StreamCopy stat_copy(decoder, f);
  stat_copy.copyAll();
}

void setup()
{
  SPIFFS.begin();
  auto cfg = out.defaultConfig(TX_MODE);
  cfg.use_apll = false; // seams to improve audio on internal DAC
  out.begin(cfg);
  decoder.begin();
  auto btconf = a2dpStream.defaultConfig(RX_MODE);
  btconf.name = "esp32 player";
  btconf.silence_on_nodata = true;
  btconf.auto_reconnect = true;
  playEventSound("/poweron.wav");
  a2dpStream.begin(btconf);
}

void loop()
{
  copier.copy();
  state = a2dpStream.isConnected();
  if (state != l_state)
  {
    if (state)
    {
      playEventSound("/connect.wav");
    }
    else
    {
      playEventSound("/disconnect.wav");
    }
    l_state = state;
  }
}

[techexplorers123]

forgot to say one more thing, I removed the audio info thingy and some how it works well even without it

[pschatzmann]

Yes that is a fact in computer science: less is often more

[techexplorers123]

yeah, seams like it. Just have to figure out how to do it well and not over complicate stuff
I am getting started in programming so sorry for the trouble.
it was a frustrating but fun few weeks. Tought me allot.
and at the end, the satisfaction of getting it working is worth all the work.
again thanks for helping me through out that instead of ignoring me.