Determine the duration of an mp3 file

[SzymonWojd]

Hi, is there any way to determine the duration in seconds of an mp3 file using this library? Also, I would be grateful if you could help me with checking how much time is left to the end of a playing file. I am building A2DP audio player which streams mp3 files and this information would be really helpful for me.

[pschatzmann]

For the first question: google is your friend!

For the second: just read the actual file position and compare it with the total file size

[SzymonWojd]

Thank you for the answer. How can I read the actual file position? Is there a function in your library that does that?

[pschatzmann]

The AudioPlayer provides you a pointer to the actual stream.: In your case this is a pointer to a File, so you can just cast it to (File*).

[SzymonWojd]

I wrote this lines of code:
File pFile = (File)player.getStream();
Serial.println(pFile->position());
However when I try to run the code my ESP32 just keeps resetting. Do you know what might be a problem?

[pschatzmann]

It should be
File* pFile = (File*)player.getStream();
And before using it, you must make sure that it is not nullptr!

[SzymonWojd]

I have been trying to figure out why my code is not working (problem with resetting esp32 still occurs (on serial monitor i get information that it is Guru Meditation Error: Core 1 panic'ed)). This is my code:
if(playerI2S.getStream() != nullptr){
File* pFile = (File*)player.getStream();
Serial.println(pFile->position());
}
For me code this line was a problem: Serial.println(pFile->position()); and to be specific this function: pFile->position() even if I changed it to something like pFile->size() it still didn't feel like working...

[pschatzmann]

Which example are you using ?
Please confirm that you are using the SD library...

[SzymonWojd]

I am using player-sdfat-a2dp example and yes i am using SD library.

[pschatzmann]

No. you are using the SDFAT library and not the SD library!
So you need to use the data types and functionality provided by that library which would be File32, I think!