[libmp3lame] Несколько вопросов.

    const int BUFFLEN = 8192;
    short int pcmbuff[BUFFLEN*2];
    unsigned char mp3buff[BUFFLEN];

    lame_global_flags *gf;
    gf = lame_init();
    lame_set_in_samplerate(gf, format.frequency());
    lame_set_num_channels(gf, format.channels());
    lame_init_params(gf);

    do
    {
        read = fread(pcmbuff, 2*sizeof(short int), BUFFLEN, in);
        if (read == 0)
        {
            write = lame_encode_flush(gf, mp3buff, BUFFLEN);
        }
        else
        {       
            write = lame_encode_buffer_interleaved(gf, pcmbuff, read, mp3buff, BUFFLEN);
         
        }
        fwrite(mp3buff, write, 1, out);
    }
    while (read != 0);