/*
   Copyright (C) 2009 Red Hat, Inc.

   This software is licensed under the GNU General Public License,
   version 2 (GPLv2) (see COPYING for details), subject to the
   following clarification.

   With respect to binaries built using the Microsoft(R) Windows
   Driver Kit (WDK), GPLv2 does not extend to any code contained in or
   derived from the WDK ("WDK Code").  As to WDK Code, by using or
   distributing such binaries you agree to be bound by the Microsoft
   Software License Terms for the WDK.  All WDK Code is considered by
   the GPLv2 licensors to qualify for the special exception stated in
   section 3 of GPLv2 (commonly known as the system library
   exception).

   There is NO WARRANTY for this software, express or implied,
   including the implied warranties of NON-INFRINGEMENT, TITLE,
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
*/

#ifdef QUIC_FAMILY_8BPC
#undef QUIC_FAMILY_8BPC
#define FNAME(name) name##_8bpc
#define VNAME(name) name##_8bpc
#define BPC 8
#endif


#ifdef QUIC_FAMILY_5BPC
#undef QUIC_FAMILY_5BPC
#define FNAME(name) name##_5bpc
#define VNAME(name) name##_5bpc
#define BPC 5
#endif


static unsigned int FNAME(golomb_code_len)(const BYTE n, const unsigned int l)
{
    if (n < VNAME(family).nGRcodewords[l]) {
        return (n >> l) + 1 + l;
    } else {
        return VNAME(family).notGRcwlen[l];
    }
}

static void FNAME(golomb_coding)(const BYTE n, const unsigned int l, unsigned int * const codeword,
                                 unsigned int * const codewordlen)
{
    if (n < VNAME(family).nGRcodewords[l]) {
        (*codeword) = bitat[l] | (n & bppmask[l]);
        (*codewordlen) = (n >> l) + l + 1;
    } else {
        (*codeword) = n - VNAME(family).nGRcodewords[l];
        (*codewordlen) = VNAME(family).notGRcwlen[l];
    }
}

unsigned int FNAME(golomb_decoding)(const unsigned int l, const unsigned int bits,
                                    unsigned int * const codewordlen)
{
    if (bits > VNAME(family).notGRprefixmask[l]) { /*GR*/
        const unsigned int zeroprefix = cnt_l_zeroes(bits);       /* leading zeroes in codeword */
        const unsigned int cwlen = zeroprefix + 1 + l;            /* codeword length */
        (*codewordlen) = cwlen;
        return (zeroprefix << l) | ((bits >> (32 - cwlen)) & bppmask[l]);
    } else { /* not-GR */
        const unsigned int cwlen = VNAME(family).notGRcwlen[l];
        (*codewordlen) = cwlen;
        return VNAME(family).nGRcodewords[l] + ((bits) >> (32 - cwlen) &
                                                bppmask[VNAME(family).notGRsuffixlen[l]]);
    }
}

/* update the bucket using just encoded curval */
static void FNAME(update_model)(CommonState *state, s_bucket * const bucket,
                                const BYTE curval, unsigned int bpp)
{
    COUNTER * const pcounters = bucket->pcounters;
    unsigned int i;
    unsigned int bestcode;
    unsigned int bestcodelen;
    //unsigned int bpp = encoder->bpp;

    /* update counters, find minimum */

    bestcode = bpp - 1;
    bestcodelen = (pcounters[bestcode] += FNAME(golomb_code_len)(curval, bestcode));

    for (i = bpp - 2; i < bpp; i--) { /* NOTE: expression i<bpp for signed int i would be: i>=0 */
        const unsigned int ithcodelen = (pcounters[i] += FNAME(golomb_code_len)(curval, i));

        if (ithcodelen < bestcodelen) {
            bestcode = i;
            bestcodelen = ithcodelen;
        }
    }

    bucket->bestcode = bestcode; /* store the found minimum */

    if (bestcodelen > state->wm_trigger) { /* halving counters? */
        for (i = 0; i < bpp; i++) {
            pcounters[i] >>= 1;
        }
    }
}

static s_bucket *FNAME(find_bucket)(Channel *channel, const unsigned int val)
{
    ASSERT(channel->encoder->usr, val < (0x1U << BPC));

    return channel->_buckets_ptrs[val];
}

#undef FNAME
#undef VNAME
#undef BPC