audio.getAudioFileDuration() returns zero seconds

[JTElectronicsNZ]

GitHub newbie so be gentle... Thanks :-)

I want to display the MP3 file approximate total play time (in minutes and seconds) so when I use the audio.getAudioFileDuration() function it always returns zero seconds. I can successfully calculate the play time in seconds using audio.getFileSize() and audio.getBitRate() to be 68 seconds but I don't know why audio.getAudioFileDuration() always returns zero seconds. I wait for "BitRate:" info to be displayed before I try to obtain the getAudioFileDuration information as in the code snippet below, and substitute me calculated playTime value if getAudioFileDuration is zero. Also at the bottom is the serial output (from Arduino IDE serial monitor) showing the various values with "playTime" being my calculated value. Not that it probably matters but board type is set to "ESP32 Dev Module" and the sounds play perfectly fine. I have downloaded the latest ESP32-audioI2s library code today. I get the same problem of zero file duration returned when playing MP3's from SD card or from SPIFFS, but I can always calculate them correctly. Please let me know if you need more code to replicate the problem.

Code to play file from SD card, or maybe SPIFFS

  if (!audio.connecttoFS(SD,"/waiting.mp3") ) {
    audio.connecttoFS(SPIFFS, "CantFindTheSoundFile.mp3");
    errorBlinker(5);  //SD card file not found
  }

Code to display audio file information

void audio_info(const char *info) {
  Serial.print("Audio:info       "); Serial.println(info);
  const char* searchForBitRate = "BitRate:";
  if ( strstr(info, searchForBitRate) ) { //detect when "BitRate" info is displayed
    unsigned long audioFileDuration = audio.getAudioFileDuration();
    Serial.print("audioFileDuration: "); Serial.println(audioFileDuration);
    if (audioFileDuration == 0) {  //yeah, getAudioFileDuration ALWAYS returns zero...
      unsigned long fileSize = audio.getFileSize();
      Serial.print("fileSize: "); Serial.println(fileSize);
      unsigned long bitRate = audio.getBitRate();
      Serial.print("bitRate: "); Serial.println(bitRate);
      unsigned long playTime = audio.getFileSize()*8 / bitRate;
      Serial.print("playTime: "); Serial.println(playTime);
      audioFileDuration = playTime; //update to use my calculated audio play time
    }
    Serial.print("Sound will be playing for ");
    if (audioFileDuration > 59) {
      Serial.print(audioFileDuration / 60); //get whole minutes
      Serial.print(" minutes and ");
    }
    Serial.print(audioFileDuration % 60); //get remainder seconds
    Serial.print(" seconds at volume "); Serial.println(audio.getVolume() );
  }
}

21:32:37.048 -> Starting SD Card... 21:32:37.142 -> SD Card Type: SDHC 21:32:37.142 -> SD Card size: 3724MB 21:32:37.142 -> SD Card files: 21:32:37.142 -> Listing directory: / 21:32:37.142 -> DIR : System Volume Information 21:32:37.142 -> FILE: waiting.mp3 SIZE: 2735168 21:32:37.142 -> Audio:info PSRAM found, inputBufferSize: 283615 bytes 21:32:37.142 -> Audio:info buffers freed, free Heap: 270348 bytes 21:32:37.142 -> Audio:info Reading file: "/waiting.mp3" 21:32:37.142 -> Audio:info MP3Decoder has been initialized, free Heap: 242628 bytes 21:32:37.835 -> Audio:info Content-Length: 2735168 21:32:37.835 -> Audio:info ID3 framesSize: 10 21:32:37.835 -> Audio:info ID3 version: 2.3 21:32:37.835 -> Audio:info ID3 normal frames 21:32:37.882 -> Audio:info Audio-Length: 2735158 21:32:37.882 -> Audio:info stream ready 21:32:37.882 -> Audio:info syncword found at pos 950 21:32:37.882 -> Audio:info syncword found at pos 0 21:32:37.929 -> Audio:info Channels: 2 21:32:37.929 -> Audio:info SampleRate: 48000 21:32:37.929 -> Audio:info BitsPerSample: 16 21:32:37.929 -> Audio:info BitRate: 320000 21:32:37.929 -> audioFileDuration: 0 21:32:37.929 -> fileSize: 2735168 21:32:37.929 -> bitRate: 320000 21:32:37.929 -> playTime: 68 21:32:37.929 -> Sound will be playing for 1 minutes and 8 seconds at volume 10 21:33:46.245 -> Audio:info Closing audio file 21:33:46.245 -> Audio:info End of file "waiting.mp3" 21:33:46.245 -> Audio:eof_mp3 waiting.mp3 21:33:46.245 -> Sound has stopped playing.

[JTElectronicsNZ]

It looks like m_avr_bitrate is zero so I added this line of code near the beginning of the Audio::getAudioFileDuration() function in file Audio.cpp and the audio.getAudioFileDuration() function now returns 64 seconds (instead of zero) which is close to correct.

m_avr_bitrate = m_bitRate;

[schreibfaul1]

Hello JTElectronicsNZ, the bit rate can be variable, I determine the bit rate several times at the beginning of the file and then form the mean value. this is my test code, the timer is called every second

ticker.attach(1, tcr1s);

void tcr1s(){
   uint32_t act=audio.getAudioCurrentTime();
   uint32_t afd=audio.getAudioFileDuration();
    if(audio.isRunning())log_i("audioCurrentTime: %i:%02d - duration: %i:%02d", (act/60), (act%60) , (afd/60), (afd%60));
}

[ 5191][I][main.cpp:405] tcr1s(): audioCurrentTime: 0:00 - duration: 5:04 [ 6191][I][main.cpp:405] tcr1s(): audioCurrentTime: 0:01 - duration: 5:12 [ 7191][I][main.cpp:405] tcr1s(): audioCurrentTime: 0:02 - duration: 5:04 [ 8191][I][main.cpp:405] tcr1s(): audioCurrentTime: 0:03 - duration: 5:04 [ 9191][I][main.cpp:405] tcr1s(): audioCurrentTime: 0:04 - duration: 4:56 [ 10191][I][main.cpp:405] tcr1s(): audioCurrentTime: 0:05 - duration: 4:56 [ 11191][I][main.cpp:405] tcr1s(): audioCurrentTime: 0:06 - duration: 4:56 [ 12191][I][main.cpp:405] tcr1s(): audioCurrentTime: 0:07 - duration: 4:56 [ 13191][I][main.cpp:405] tcr1s(): audioCurrentTime: 0:08 - duration: 4:56 [ 14191][I][main.cpp:405] tcr1s(): audioCurrentTime: 0:09 - duration: 4:56

tested with this mp3 file seconds-VBR.mp3.txt

[stale[bot]]

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