How to use

computeDuration

method

in

javax.media.format.AudioFormat

/**
 * Get the length of the audio in this {@link TranscriptionRequest} in
 * milliseconds
 *
 * @return the duration of the audio in milliseconds or -1 when unknown
 */
public long getDurationInMs()
{
  if(this.format == null)
  {
    return -1;
  }
  return TimeUnit.NANOSECONDS.toMillis(
    this.format.computeDuration(this.audio.length));
}

/**
 * Gets the length in milliseconds of the media in a specific
 * <tt>Buffer</tt> (often referred to as duration).
 *
 * @param buffer the <tt>Buffer</tt> which contains media the length in
 * milliseconds of which is to be calculated
 * @return the length in milliseconds of the media in <tt>buffer</tt> if
 * there actually is media in <tt>buffer</tt> and its length in milliseconds
 * can be calculated; otherwise, <tt>0</tt>
 */
private long getLengthInMillis(Buffer buffer)
{
  int length = buffer.getLength();
  if (length < 1)
    return 0;
  Format format = buffer.getFormat();
  if (format == null)
  {
    format = getFormat();
    if (format == null)
      return 0;
  }
  if (!(format instanceof AudioFormat))
    return 0;
  AudioFormat audioFormat = (AudioFormat) format;
  long duration = audioFormat.computeDuration(length);
  return (duration < 1) ? 0 : (duration / 1000000);
}

= (audioStreamFormat.computeDuration(audioStreamLength)
    + 999999)
  / 1000000;