fh = ((FrameHeader *)(mp3DecInfo->FrameHeaderPS));

    /* read header fields - use bitmasks instead of GetBits() for speed, since format never varies */
    verIdx =         (buf[1] >> 3) & 0x03;
    fh->ver =        (MPEGVersion)( verIdx == 0 ? MPEG25 : ((verIdx & 0x01) ? MPEG1 : MPEG2) );
    fh->layer = 4 - ((buf[1] >> 1) & 0x03);     /* easy mapping of index to layer number, 4 = error */
    fh->crc =   1 - ((buf[1] >> 0) & 0x01);
    fh->brIdx =      (buf[2] >> 4) & 0x0f;
    fh->srIdx =      (buf[2] >> 2) & 0x03;
    fh->paddingBit = (buf[2] >> 1) & 0x01;
    fh->privateBit = (buf[2] >> 0) & 0x01;
    fh->sMode =      (StereoMode)((buf[3] >> 6) & 0x03);      /* maps to correct enum (see definition) */    
    fh->modeExt =    (buf[3] >> 4) & 0x03;
    fh->copyFlag =   (buf[3] >> 3) & 0x01;
    fh->origFlag =   (buf[3] >> 2) & 0x01;
    fh->emphasis =   (buf[3] >> 0) & 0x03;

    /* check parameters to avoid indexing tables with bad values */
    if (fh->srIdx == 3 || fh->layer == 4 || fh->brIdx == 15)
        {  
        return -1;
        }