Media Foundation Encoder to convert Wav to Mp3 adds silence at beginning and end of final mp3 file.

[Febz]

HI! I'm using the following code to convert a bunch of wav files into mp3

using (var reader = new WaveFileReader(wavFilePath))
{
    try
    {
        MediaFoundationEncoder.EncodeToMp3(reader, mp3FilePath);
    }
    catch (InvalidOperationException ex)
    {
        Console.WriteLine(ex.Message);
    }
}

but when I compare the wav and mp3 files inside a sequencer or similar (Audacity for example) the mp3 file always has extra silence at both ends, making it longer.
Unfortunately just trimming both ends of the file would be tricky because some of the wav files already have silences and I need to keep them of the same length in the mp3 files.

Any help will be greatly appreciated <3