Exemple #1
0
        /*
         * int init_encode(StaticCodeBook s){
         *      //memset(c,0,sizeof(codebook));
         *      c=s;
         *      entries=s.entries;
         *      dim=s.dim;
         *      codelist=make_words(s.lengthlist, s.entries);
         *      valuelist=s.unquantize();
         *      return(0);
         * }
         */

        internal int init_decode(StaticCodeBook s)
        {
            //memset(c,0,sizeof(codebook));
            c         = s;
            entries   = s.entries;
            dim       = s.dim;
            valuelist = s.unquantize();

            decode_tree = make_decode_tree();
            if (decode_tree == null)
            {
                //goto err_out;
                clear();
                return(-1);
            }
            return(0);
            //  err_out:
            //    vorbis_book_clear(c);
            //    return(-1);
        }
Exemple #2
0
        // Decode side is specced and easier, because we don't need to find
        // matches using different criteria; we simply read and map.  There are
        // two things we need to do 'depending':
        //
        // We may need to support interleave.  We don't really, but it's
        // convenient to do it here rather than rebuild the vector later.
        //
        // Cascades may be additive or multiplicitive; this is not inherent in
        // the codebook, but set in the code using the codebook.  Like
        // interleaving, it's easiest to do it here.
        // stage==0 -> declarative (set the value)
        // stage==1 -> additive
        // stage==2 -> multiplicitive

        // returns the entry number or -1 on eof
        internal int decode(csBuffer b)
        {
            int       ptr = 0;
            DecodeAux t   = decode_tree;
            int       lok = b.look(t.tabn);

            //System.err.println(this+" "+t+" lok="+lok+", tabn="+t.tabn);

            if (lok >= 0)
            {
                ptr = t.tab[lok];
                b.adv(t.tabl[lok]);
                if (ptr <= 0)
                {
                    return(-ptr);
                }
            }
            do
            {
                switch (b.read1())
                {
                case 0:
                    ptr = t.ptr0[ptr];
                    break;

                case 1:
                    ptr = t.ptr1[ptr];
                    break;

                case -1:
                default:
                    return(-1);
                }
            }while(ptr > 0);
            return(-ptr);
        }
Exemple #3
0
        // build the decode helper tree from the codewords
        internal DecodeAux make_decode_tree()
        {
            int       top = 0;
            DecodeAux t   = new DecodeAux();

            int[] ptr0     = t.ptr0 = new int[entries * 2];
            int[] ptr1     = t.ptr1 = new int[entries * 2];
            int[] codelist = make_words(c.lengthlist, c.entries);

            if (codelist == null)
            {
                return(null);
            }
            t.aux = entries * 2;

            for (int i = 0; i < entries; i++)
            {
                if (c.lengthlist[i] > 0)
                {
                    int ptr = 0;
                    int j;
                    for (j = 0; j < c.lengthlist[i] - 1; j++)
                    {
                        int bit = (int)(((uint)codelist[i] >> j) & 1);
                        if (bit == 0)
                        {
                            if (ptr0[ptr] == 0)
                            {
                                ptr0[ptr] = ++top;
                            }
                            ptr = ptr0[ptr];
                        }
                        else
                        {
                            if (ptr1[ptr] == 0)
                            {
                                ptr1[ptr] = ++top;
                            }
                            ptr = ptr1[ptr];
                        }
                    }

                    if ((((uint)codelist[i] >> j) & 1) == 0)
                    {
                        ptr0[ptr] = -i;
                    }
                    else
                    {
                        ptr1[ptr] = -i;
                    }
                }
            }
            //free(codelist);

            t.tabn = ilog(entries) - 4;

            if (t.tabn < 5)
            {
                t.tabn = 5;
            }
            int n = 1 << t.tabn;

            t.tab  = new int[n];
            t.tabl = new int[n];
            for (int i = 0; i < n; i++)
            {
                int p = 0;
                int j = 0;
                for (j = 0; j < t.tabn && (p > 0 || j == 0); j++)
                {
                    if ((i & (1 << j)) != 0)
                    {
                        p = ptr1[p];
                    }
                    else
                    {
                        p = ptr0[p];
                    }
                }
                t.tab[i]  = p;               // -code
                t.tabl[i] = j;               // length
            }

            return(t);
        }