BitMiracle.LibJpeg.Classic.Internal.huff_entropy_decoder.jpeg_huff_decode C# (CSharp) Method

        protected static int jpeg_huff_decode(ref bitread_working_state state, int get_buffer, int bits_left, d_derived_tbl htbl, int min_bits)
        {
            /* HUFF_DECODE has determined that the code is at least min_bits */
            /* bits long, so fetch that many bits in one swoop. */
            int l = min_bits;
            if (!CHECK_BIT_BUFFER(ref state, l, ref get_buffer, ref bits_left))
                return -1;

            int code = GET_BITS(l, get_buffer, ref bits_left);

            /* Collect the rest of the Huffman code one bit at a time. */
            /* This is per Figure F.16 in the JPEG spec. */

            while (code > htbl.maxcode[l])
            {
                code <<= 1;
                if (!CHECK_BIT_BUFFER(ref state, 1, ref get_buffer, ref bits_left))
                    return -1;

                code |= GET_BITS(1, get_buffer, ref bits_left);
                l++;
            }

            /* Unload the local registers */
            state.get_buffer = get_buffer;
            state.bits_left = bits_left;

            /* With garbage input we may reach the sentinel value l = 17. */

            if (l > 16)
            {
                state.cinfo.WARNMS(J_MESSAGE_CODE.JWRN_HUFF_BAD_CODE);
                /* fake a zero as the safest result */
                return 0;
            }

            return htbl.pub.Huffval[code + htbl.valoffset[l]];
        }
    }