Added VU meter level read function

[Frank-Bemelman]

Hi Cellie,

Still having fun with my never ending project.

Noticed that some stations do connect, but sometimes apperently 'off line' as they just stream the sound of silence...
So I considered skipping those, and pick the next station in my list. Could do that after perhaps 5 seconds of continious silence.

For that I need the level of the actual sound being played. So I made this new member:

uint8_t ESP32_VS1053_Stream::getVuMeter()
{ // read  VU-meter registers
  // turn on Vu meter if need be

  if(!_http && !_playingFile)return 0;

  uint16_t regvalue = _vs1053->readRegister(SCI_STATUS); 
  if((regvalue & 0x0200)==0) _vs1053->writeRegister(SCI_STATUS, (regvalue | 0x200)); 
    
  uint16_t vu_values = _vs1053->readRegister(SCI_AICTRL3); 
  uint8_t left_channel = highByte(vu_values);
  uint8_t right_channel = lowByte(vu_values);

  return max(left_channel, right_channel);
}

And in ESP32_VS1053_Stream.h:

uint8_t getVuMeter();
...
const uint8_t SCI_AICTRL3 = 0x0F;
const uint8_t SCI_STATUS = 0x01;

So now I can check the real audio level, with stream.getVuMeter(). When nothing plays, return values are 0, when streaming music the average is 70-90. Pauses between tracks, maybe as low as 6.

A while back I added _vs1053->switchToMp3Mode(); in various spots, as I thought that was good for... yes for what, Since that also removes the loaded patches, I had no Vu meter functionality. So I had removed all those calls, and today it doesn't seem to cause new undesireable behviour, so it was probably a silly move of me to put those in, in the first place. Oh well ;-)

Cheers,
Frank

[CelliesProjects]

Hey Frank,

Good idea.

I would like to implement a vu meter, but atm I am rather busy irl.
And I have some coding ideas/work on the back burner already.

Thanks for showing how simple it can be.
-simple after all the head banging and lots of detours, same here-

[Frank-Bemelman]

No worries. Btw, later I read that turning on the vu meter also eats a bit more processing power of the VS1053.
Could cause stuttering - not that I noticed, but ok.

So, you might want to turn it off, at every start or end of a stream:

regvalue = _vs1053->readRegister(SCI_STATUS); 
if((regvalue & 0x0200)!=0) _vs1053->writeRegister(SCI_STATUS, (regvalue ^ 0x200)); 

And turn it on when you read the values.

Right now I am running all 120.000 urls in a sequential test, but only when my radio is off/asleep. And write the ones that fail to a log file.
About 2-4 seconds for each one. So that will take ~100 hours.. It stops when turned on and resumes testing when off. Since it's not off all the time, it will probably take a week. Almost feels like abuse, connecting to all those urls and quit immediately once connected ;-)

Cheers,
Frank