humble-video-noarch/src/main/java/io/humble/video/customio/DataInputOutputHandler.java
public long seek(long offset, int whence)
  {
    if (mOpenStream == null)
      return -1;
    if (!(mOpenStream instanceof RandomAccessFile))
      return -1;
    final RandomAccessFile file = (RandomAccessFile) mOpenStream;
    try
    {
      final long seek;
      if (whence == SEEK_SET)
        seek = offset;
      else if (whence == SEEK_CUR)
        seek = file.getFilePointer() + offset;
      else if (whence == SEEK_END)
        seek = file.length() + offset;
      else if (whence == SEEK_SIZE)
        // odd feature of the protocol handler; this request
        // just returns the file size without actually seeking
        return (int) file.length();
      else
      {
        log.error("invalid seek value \"{}\" for file: {}", whence, file);
        return -1;
      }

      file.seek(seek);
      return seek;
    }
    catch (IOException e)
    {
      log.debug("got io exception \"{}\" while seeking in: {}", e
          .getMessage(), file);
      return -1;
    }
  }
public long seek(long offset, int whence)
  {
    if (mOpenStream == null)
      return -1;
    if (!(mOpenStream instanceof RandomAccessFile))
      return -1;
    final RandomAccessFile file = (RandomAccessFile) mOpenStream;
    try
    {
      final long seek;
      if (whence == SEEK_SET)
        seek = offset;
      else if (whence == SEEK_CUR)
        seek = file.getFilePointer() + offset;
      else if (whence == SEEK_END)
        seek = file.length() + offset;
      else if (whence == SEEK_SIZE)
        // odd feature of the protocol handler; this request
        // just returns the file size without actually seeking
        return (int) file.length();
      else
      {
        log.error("invalid seek value \"{}\" for file: {}", whence, file);
        return -1;
      }

      file.seek(seek);
      return seek;
    }
    catch (IOException e)
    {
      log.debug("got io exception \"{}\" while seeking in: {}", e
          .getMessage(), file);
      return -1;
    }
  }
{@inheritDoc}

This method is not supported on this class and always return -1;