libopenjpeg/mqc.c - external/github.com/uclouvain/openjpeg - Git at Google

 /*
  * Copyright (c) 2001-2002, David Janssens
  * Copyright (c) 2002-2003, Yannick Verschueren
  * Copyright (c) 2002-2003,  Communications and remote sensing Laboratory, Universite catholique de Louvain, Belgium
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS `AS IS'
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.
  */

 #include "mqc.h"
 #include <stdio.h>

 /* <summary> */
 /* This struct defines the state of a context. */
 /* </summary> */
 typedef struct mqc_state_s {
 	unsigned int qeval;	        /* the probability of the Least Probable Symbol (0.75->0x8000, 1.5->0xffff) */
 	int mps;		        /* the Most Probable Symbol (0 or 1) */
 	struct mqc_state_s *nmps;	/* next state if the next encoded symbol is the MPS */
 	struct mqc_state_s *nlps;	/* next state if the next encoded symbol is the LPS */
 } mqc_state_t;

 /* <summary> */
 /* This array defines all the possible states for a context. */
 /* </summary> */
 mqc_state_t mqc_states[47 * 2] = {
 	{0x5601, 0, &mqc_states[2], &mqc_states[3]},
 	{0x5601, 1, &mqc_states[3], &mqc_states[2]},
 	{0x3401, 0, &mqc_states[4], &mqc_states[12]},
 	{0x3401, 1, &mqc_states[5], &mqc_states[13]},
 	{0x1801, 0, &mqc_states[6], &mqc_states[18]},
 	{0x1801, 1, &mqc_states[7], &mqc_states[19]},
 	{0x0ac1, 0, &mqc_states[8], &mqc_states[24]},
 	{0x0ac1, 1, &mqc_states[9], &mqc_states[25]},
 	{0x0521, 0, &mqc_states[10], &mqc_states[58]},
 	{0x0521, 1, &mqc_states[11], &mqc_states[59]},
 	{0x0221, 0, &mqc_states[76], &mqc_states[66]},
 	{0x0221, 1, &mqc_states[77], &mqc_states[67]},
 	{0x5601, 0, &mqc_states[14], &mqc_states[13]},
 	{0x5601, 1, &mqc_states[15], &mqc_states[12]},
 	{0x5401, 0, &mqc_states[16], &mqc_states[28]},
 	{0x5401, 1, &mqc_states[17], &mqc_states[29]},
 	{0x4801, 0, &mqc_states[18], &mqc_states[28]},
 	{0x4801, 1, &mqc_states[19], &mqc_states[29]},
 	{0x3801, 0, &mqc_states[20], &mqc_states[28]},
 	{0x3801, 1, &mqc_states[21], &mqc_states[29]},
 	{0x3001, 0, &mqc_states[22], &mqc_states[34]},
 	{0x3001, 1, &mqc_states[23], &mqc_states[35]},
 	{0x2401, 0, &mqc_states[24], &mqc_states[36]},
 	{0x2401, 1, &mqc_states[25], &mqc_states[37]},
 	{0x1c01, 0, &mqc_states[26], &mqc_states[40]},
 	{0x1c01, 1, &mqc_states[27], &mqc_states[41]},
 	{0x1601, 0, &mqc_states[58], &mqc_states[42]},
 	{0x1601, 1, &mqc_states[59], &mqc_states[43]},
 	{0x5601, 0, &mqc_states[30], &mqc_states[29]},
 	{0x5601, 1, &mqc_states[31], &mqc_states[28]},
 	{0x5401, 0, &mqc_states[32], &mqc_states[28]},
 	{0x5401, 1, &mqc_states[33], &mqc_states[29]},
 	{0x5101, 0, &mqc_states[34], &mqc_states[30]},
 	{0x5101, 1, &mqc_states[35], &mqc_states[31]},
 	{0x4801, 0, &mqc_states[36], &mqc_states[32]},
 	{0x4801, 1, &mqc_states[37], &mqc_states[33]},
 	{0x3801, 0, &mqc_states[38], &mqc_states[34]},
 	{0x3801, 1, &mqc_states[39], &mqc_states[35]},
 	{0x3401, 0, &mqc_states[40], &mqc_states[36]},
 	{0x3401, 1, &mqc_states[41], &mqc_states[37]},
 	{0x3001, 0, &mqc_states[42], &mqc_states[38]},
 	{0x3001, 1, &mqc_states[43], &mqc_states[39]},
 	{0x2801, 0, &mqc_states[44], &mqc_states[38]},
 	{0x2801, 1, &mqc_states[45], &mqc_states[39]},
 	{0x2401, 0, &mqc_states[46], &mqc_states[40]},
 	{0x2401, 1, &mqc_states[47], &mqc_states[41]},
 	{0x2201, 0, &mqc_states[48], &mqc_states[42]},
 	{0x2201, 1, &mqc_states[49], &mqc_states[43]},
 	{0x1c01, 0, &mqc_states[50], &mqc_states[44]},
 	{0x1c01, 1, &mqc_states[51], &mqc_states[45]},
 	{0x1801, 0, &mqc_states[52], &mqc_states[46]},
 	{0x1801, 1, &mqc_states[53], &mqc_states[47]},
 	{0x1601, 0, &mqc_states[54], &mqc_states[48]},
 	{0x1601, 1, &mqc_states[55], &mqc_states[49]},
 	{0x1401, 0, &mqc_states[56], &mqc_states[50]},
 	{0x1401, 1, &mqc_states[57], &mqc_states[51]},
 	{0x1201, 0, &mqc_states[58], &mqc_states[52]},
 	{0x1201, 1, &mqc_states[59], &mqc_states[53]},
 	{0x1101, 0, &mqc_states[60], &mqc_states[54]},
 	{0x1101, 1, &mqc_states[61], &mqc_states[55]},
 	{0x0ac1, 0, &mqc_states[62], &mqc_states[56]},
 	{0x0ac1, 1, &mqc_states[63], &mqc_states[57]},
 	{0x09c1, 0, &mqc_states[64], &mqc_states[58]},
 	{0x09c1, 1, &mqc_states[65], &mqc_states[59]},
 	{0x08a1, 0, &mqc_states[66], &mqc_states[60]},
 	{0x08a1, 1, &mqc_states[67], &mqc_states[61]},
 	{0x0521, 0, &mqc_states[68], &mqc_states[62]},
 	{0x0521, 1, &mqc_states[69], &mqc_states[63]},
 	{0x0441, 0, &mqc_states[70], &mqc_states[64]},
 	{0x0441, 1, &mqc_states[71], &mqc_states[65]},
 	{0x02a1, 0, &mqc_states[72], &mqc_states[66]},
 	{0x02a1, 1, &mqc_states[73], &mqc_states[67]},
 	{0x0221, 0, &mqc_states[74], &mqc_states[68]},
 	{0x0221, 1, &mqc_states[75], &mqc_states[69]},
 	{0x0141, 0, &mqc_states[76], &mqc_states[70]},
 	{0x0141, 1, &mqc_states[77], &mqc_states[71]},
 	{0x0111, 0, &mqc_states[78], &mqc_states[72]},
 	{0x0111, 1, &mqc_states[79], &mqc_states[73]},
 	{0x0085, 0, &mqc_states[80], &mqc_states[74]},
 	{0x0085, 1, &mqc_states[81], &mqc_states[75]},
 	{0x0049, 0, &mqc_states[82], &mqc_states[76]},
 	{0x0049, 1, &mqc_states[83], &mqc_states[77]},
 	{0x0025, 0, &mqc_states[84], &mqc_states[78]},
 	{0x0025, 1, &mqc_states[85], &mqc_states[79]},
 	{0x0015, 0, &mqc_states[86], &mqc_states[80]},
 	{0x0015, 1, &mqc_states[87], &mqc_states[81]},
 	{0x0009, 0, &mqc_states[88], &mqc_states[82]},
 	{0x0009, 1, &mqc_states[89], &mqc_states[83]},
 	{0x0005, 0, &mqc_states[90], &mqc_states[84]},
 	{0x0005, 1, &mqc_states[91], &mqc_states[85]},
 	{0x0001, 0, &mqc_states[90], &mqc_states[86]},
 	{0x0001, 1, &mqc_states[91], &mqc_states[87]},
 	{0x5601, 0, &mqc_states[92], &mqc_states[92]},
 	{0x5601, 1, &mqc_states[93], &mqc_states[93]},
 };

 #define MQC_NUMCTXS 32

 unsigned int mqc_c;
 unsigned int mqc_a;
 unsigned int mqc_ct;
 unsigned char *mqc_bp;
 unsigned char *mqc_start;
 unsigned char *mqc_end;
 mqc_state_t *mqc_ctxs[MQC_NUMCTXS];
 mqc_state_t **mqc_curctx;

 /* <summary> */
 /* Return the number of bytes already encoded. */
 /* </summary> */
 int mqc_numbytes()
 {
 	return mqc_bp - mqc_start;
 }

 /* <summary> */
 /* Output a byte, doing bit-stuffing if necessary. */
 /* After a 0xff byte, the next byte must be smaller than 0x90 */
 /* </summary> */
 void mqc_byteout()
 {
 	if (*mqc_bp == 0xff) {
 		mqc_bp++;
 		*mqc_bp = mqc_c >> 20;
 		mqc_c &= 0xfffff;
 		mqc_ct = 7;
 	} else {
 		if ((mqc_c & 0x8000000) == 0) {	/* ((mqc_c&0x8000000)==0) CHANGE */
 			mqc_bp++;
 			*mqc_bp = mqc_c >> 19;
 			mqc_c &= 0x7ffff;
 			mqc_ct = 8;
 		} else {
 			(*mqc_bp)++;
 			if (*mqc_bp == 0xff) {
 				mqc_c &= 0x7ffffff;
 				mqc_bp++;
 				*mqc_bp = mqc_c >> 20;
 				mqc_c &= 0xfffff;
 				mqc_ct = 7;
 			} else {
 				mqc_bp++;
 				*mqc_bp = mqc_c >> 19;
 				mqc_c &= 0x7ffff;
 				mqc_ct = 8;
 			}
 		}
 	}
 }

 /* <summary> */
 /* Renormalize mqc_a and mqc_c while encoding, so that mqc_a stays between 0x8000 and 0x10000 */
 /* </summary> */
 void mqc_renorme()
 {
 	do {
 		mqc_a <<= 1;
 		mqc_c <<= 1;
 		mqc_ct--;
 		if (mqc_ct == 0) {
 			mqc_byteout();
 		}
 	} while ((mqc_a & 0x8000) == 0);
 }

 /* <summary> */
 /* Encode the most probable symbol. */
 /* </summary> */
 void mqc_codemps()
 {
 	mqc_a -= (*mqc_curctx)->qeval;
 	if ((mqc_a & 0x8000) == 0) {
 		if (mqc_a < (*mqc_curctx)->qeval) {
 			mqc_a = (*mqc_curctx)->qeval;
 		} else {
 			mqc_c += (*mqc_curctx)->qeval;
 		}
 		*mqc_curctx = (*mqc_curctx)->nmps;
 		mqc_renorme();
 	} else {
 		mqc_c += (*mqc_curctx)->qeval;
 	}
 }

 /* <summary> */
 /* Encode the most least symbol. */
 /* </summary> */
 void mqc_codelps()
 {
 	mqc_a -= (*mqc_curctx)->qeval;
 	if (mqc_a < (*mqc_curctx)->qeval) {
 		mqc_c += (*mqc_curctx)->qeval;
 	} else {
 		mqc_a = (*mqc_curctx)->qeval;
 	}
 	*mqc_curctx = (*mqc_curctx)->nlps;
 	mqc_renorme();
 }

 /* <summary> */
 /* Initialize encoder. */
 /* </summary> */
 /* <param name="bp">Output buffer.</param> */
 void mqc_init_enc(unsigned char *bp)
 {
 	mqc_setcurctx(0);
 	mqc_a = 0x8000;
 	mqc_c = 0;
 	mqc_bp = bp - 1;
 	mqc_ct = 12;
 	if (*mqc_bp == 0xff) {
 		mqc_ct = 13;
 	}
 	mqc_start = bp;
 }

 /* <summary> */
 /* Set current context. */
 /* </summary> */
 /* <param name="ctxno">Context number.</param> */
 void mqc_setcurctx(int ctxno)
 {
 	mqc_curctx = &mqc_ctxs[ctxno];
 }

 /* <summary> */
 /* Encode a symbol using the MQ-coder. */
 /* </summary> */
 /* <param name="d"> The symbol to be encoded (0 or 1).</param> */
 void mqc_encode(int d)
 {
 	if ((*mqc_curctx)->mps == d) {
 		mqc_codemps();
 	} else {
 		mqc_codelps();
 	}
 }

 /* <summary> */
 /* Fill mqc_c with 1's for flushing */
 /* </summary> */
 void mqc_setbits()
 {
 	unsigned int tempc = mqc_c + mqc_a;
 	mqc_c |= 0xffff;
 	if (mqc_c >= tempc) {
 		mqc_c -= 0x8000;
 	}
 }

 /* <summary> */
 /* Flush encoded data. */
 /* </summary> */
 void mqc_flush()
 {
 	mqc_setbits();
 	mqc_c <<= mqc_ct;
 	mqc_byteout();
 	mqc_c <<= mqc_ct;
 	mqc_byteout();

 	if (*mqc_bp != 0xff) {
 		mqc_bp++;
 	}
 }

 /* <summary> */
 /* not fully implemented and tested !! */
 /* BYPASS mode switch, initialization operation */
 /* JPEG 2000 p 505 */
 /* </summary> */
 void mqc_bypass_init_enc()
 {
 	mqc_c = 0;
 	mqc_ct = 8;
 	/*if (*mqc_bp == 0xff) {
 	  mqc_ct = 7;
 	  }*/
 }

 /* <summary> */
 /* not fully implemented and tested !! */
 /* BYPASS mode switch, coding operation */
 /* JPEG 2000 p 505 */
 /* </summary> */
 void mqc_bypass_enc(int d)
 {
 	mqc_ct--;
 	mqc_c = mqc_c + (d << mqc_ct);
 	if (mqc_ct == 0)
 	  {
 	    mqc_bp++;
 	    *mqc_bp = mqc_c;
 	    mqc_ct = 8;
 	    if (*mqc_bp == 0xff) {
 	      mqc_ct = 7;
 	    }
 	    mqc_c = 0;
 	  }
 }

 /* <summary> */
 /* not fully implemented and tested !! */
 /* BYPASS mode switch, flush operation */
 /* </summary> */
 int mqc_bypass_flush_enc()
 {
 	unsigned char bit_padding;

 	bit_padding = 0;

 	if (mqc_ct != 0) {
 		while (mqc_ct > 0) {
 			mqc_ct--;
 			mqc_c += bit_padding << mqc_ct;
 			bit_padding = (bit_padding + 1) & 0x01;
 		}
 		mqc_bp++;
 		*mqc_bp = mqc_c;
 		mqc_ct = 8;
 		mqc_c = 0;
 	}

 	return 1;
 }

 /* <summary> */
 /* RESET mode switch */
 /* </summary> */
 void mqc_reset_enc()
 {
 	mqc_resetstates();
 	mqc_setstate(18, 0, 46);
 	mqc_setstate(0, 0, 3);
 	mqc_setstate(1, 0, 4);
 }

 /* <summary> */
 /* mode switch RESTART (TERMALL) */
 /* </summary> */
 int mqc_restart_enc()
 {
 	int correction = 1;

 	/* <flush part> */
 	int n = 27 - 15 - mqc_ct;
 	mqc_c <<= mqc_ct;
 	while (n > 0) {
 		mqc_byteout();
 		n -= mqc_ct;
 		mqc_c <<= mqc_ct;
 	}
 	mqc_byteout();

 	return correction;
 }

 /* <summary> */
 /* mode switch RESTART (TERMALL) reinitialisation */
 /* </summary> */
 void mqc_restart_init_enc()
 {
 	/* <Re-init part> */
         mqc_setcurctx(0);
 	mqc_a = 0x8000;
 	mqc_c = 0;
 	mqc_ct = 12;
 	mqc_bp--;
 	if (*mqc_bp == 0xff) {
 		mqc_ct = 13;
 	}
 }


 /* <summary> */
 /* ERTERM mode switch  */
 /* </summary> */
 void mqc_erterm_enc()
 {
 	int k = 11 - mqc_ct + 1;

 	while (k > 0) {
 		mqc_c <<= mqc_ct;
 		mqc_ct = 0;
 		mqc_byteout();
 		k -= mqc_ct;
 	}

 	if (*mqc_bp != 0xff) {
 		mqc_byteout();
 	}
 }

 /* <summary> */
 /* SEGMARK mode switch (SEGSYM) */
 /* </summary> */
 void mqc_segmark_enc()
 {
 	int i;
 	mqc_setcurctx(18);

 	for (i = 1; i < 5; i++) {
 		mqc_encode(i % 2);
 	}
 }

 /* <summary> */
 /* </summary> */
 int mqc_mpsexchange()
 {
 	int d;
 	if (mqc_a < (*mqc_curctx)->qeval) {
 		d = 1 - (*mqc_curctx)->mps;
 		*mqc_curctx = (*mqc_curctx)->nlps;
 	} else {
 		d = (*mqc_curctx)->mps;
 		*mqc_curctx = (*mqc_curctx)->nmps;
 	}
 	return d;
 }

 /* <summary> */
 /* </summary> */
 int mqc_lpsexchange()
 {
 	int d;
 	if (mqc_a < (*mqc_curctx)->qeval) {
 		mqc_a = (*mqc_curctx)->qeval;
 		d = (*mqc_curctx)->mps;
 		*mqc_curctx = (*mqc_curctx)->nmps;
 	} else {
 		mqc_a = (*mqc_curctx)->qeval;
 		d = 1 - (*mqc_curctx)->mps;
 		*mqc_curctx = (*mqc_curctx)->nlps;
 	}
 	return d;
 }

 /* <summary> */
 /* Input a byte. */
 /* </summary> */
 void mqc_bytein()
 {
 	if (mqc_bp != mqc_end) {
 		unsigned int c;
 		if (mqc_bp + 1 != mqc_end) {
 			c = *(mqc_bp + 1);
 		} else {
 			c = 0xff;
 		}
 		if (*mqc_bp == 0xff) {
 			if (c > 0x8f) {
 				mqc_c += 0xff00;
 				mqc_ct = 8;
 			} else {
 				mqc_bp++;
 				mqc_c += c << 9;
 				mqc_ct = 7;
 			}
 		} else {
 			mqc_bp++;
 			mqc_c += c << 8;
 			mqc_ct = 8;
 		}
 	} else {
 		mqc_c += 0xff00;
 		mqc_ct = 8;
 	}
 }

 /* <summary> */
 /* Renormalize mqc_a and mqc_c while decoding. */
 /* </summary> */
 void mqc_renormd()
 {
 	do {
 		if (mqc_ct == 0) {
 			mqc_bytein();
 		}
 		mqc_a <<= 1;
 		mqc_c <<= 1;
 		mqc_ct--;
 	} while (mqc_a < 0x8000);
 }

 /* <summary> */
 /* Initialize decoder. */
 /* </summary> */
 void mqc_init_dec(unsigned char *bp, int len)
 {
 	mqc_setcurctx(0);
 	mqc_start = bp;
 	mqc_end = bp + len;
 	mqc_bp = bp;
 	mqc_c = *mqc_bp << 16;
 	mqc_bytein();
 	mqc_c <<= 7;
 	mqc_ct -= 7;
 	mqc_a = 0x8000;
 }

 /* <summary> */
 /* Decode a symbol. */
 /* </summary> */
 int mqc_decode()
 {
 	int d;
 	mqc_a -= (*mqc_curctx)->qeval;
 	if ((mqc_c >> 16) < (*mqc_curctx)->qeval) {
 		d = mqc_lpsexchange();
 		mqc_renormd();
 	} else {
 		mqc_c -= (*mqc_curctx)->qeval << 16;
 		if ((mqc_a & 0x8000) == 0) {
 			d = mqc_mpsexchange();
 			mqc_renormd();
 		} else {
 			d = (*mqc_curctx)->mps;
 		}
 	}
 	return d;
 }

 /* <summary> */
 /* Reset states of all contexts. */
 /* </summary> */
 void mqc_resetstates()
 {
 	int i;
 	for (i = 0; i < MQC_NUMCTXS; i++) {
 		mqc_ctxs[i] = mqc_states;
 	}
 }

 /* <summary> */
 /* Set the state for a context. */
 /* </summary> */
 /* <param name="ctxno">Context number</param> */
 /* <param name="msb">Most significant bit</param> */
 /* <param name="prob">Index to the probability of symbols</param> */
 void mqc_setstate(int ctxno, int msb, int prob)
 {
 	mqc_ctxs[ctxno] = &mqc_states[msb + (prob << 1)];
 }
	/*
	* Copyright (c) 2001-2002, David Janssens
	* Copyright (c) 2002-2003, Yannick Verschueren
	* Copyright (c) 2002-2003, Communications and remote sensing Laboratory, Universite catholique de Louvain, Belgium
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS `AS IS'
	* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
	* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
	* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
	* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
	* POSSIBILITY OF SUCH DAMAGE.
	*/

	#include "mqc.h"
	#include <stdio.h>

	/* <summary> */
	/* This struct defines the state of a context. */
	/* </summary> */
	typedef struct mqc_state_s {
	unsigned int qeval; /* the probability of the Least Probable Symbol (0.75->0x8000, 1.5->0xffff) */
	int mps; /* the Most Probable Symbol (0 or 1) */
	struct mqc_state_s nmps; / next state if the next encoded symbol is the MPS */
	struct mqc_state_s nlps; / next state if the next encoded symbol is the LPS */
	} mqc_state_t;

	/* <summary> */
	/* This array defines all the possible states for a context. */
	/* </summary> */
	mqc_state_t mqc_states[47 * 2] = {
	{0x5601, 0, &mqc_states[2], &mqc_states[3]},
	{0x5601, 1, &mqc_states[3], &mqc_states[2]},
	{0x3401, 0, &mqc_states[4], &mqc_states[12]},
	{0x3401, 1, &mqc_states[5], &mqc_states[13]},
	{0x1801, 0, &mqc_states[6], &mqc_states[18]},
	{0x1801, 1, &mqc_states[7], &mqc_states[19]},
	{0x0ac1, 0, &mqc_states[8], &mqc_states[24]},
	{0x0ac1, 1, &mqc_states[9], &mqc_states[25]},
	{0x0521, 0, &mqc_states[10], &mqc_states[58]},
	{0x0521, 1, &mqc_states[11], &mqc_states[59]},
	{0x0221, 0, &mqc_states[76], &mqc_states[66]},
	{0x0221, 1, &mqc_states[77], &mqc_states[67]},
	{0x5601, 0, &mqc_states[14], &mqc_states[13]},
	{0x5601, 1, &mqc_states[15], &mqc_states[12]},
	{0x5401, 0, &mqc_states[16], &mqc_states[28]},
	{0x5401, 1, &mqc_states[17], &mqc_states[29]},
	{0x4801, 0, &mqc_states[18], &mqc_states[28]},
	{0x4801, 1, &mqc_states[19], &mqc_states[29]},
	{0x3801, 0, &mqc_states[20], &mqc_states[28]},
	{0x3801, 1, &mqc_states[21], &mqc_states[29]},
	{0x3001, 0, &mqc_states[22], &mqc_states[34]},
	{0x3001, 1, &mqc_states[23], &mqc_states[35]},
	{0x2401, 0, &mqc_states[24], &mqc_states[36]},
	{0x2401, 1, &mqc_states[25], &mqc_states[37]},
	{0x1c01, 0, &mqc_states[26], &mqc_states[40]},
	{0x1c01, 1, &mqc_states[27], &mqc_states[41]},
	{0x1601, 0, &mqc_states[58], &mqc_states[42]},
	{0x1601, 1, &mqc_states[59], &mqc_states[43]},
	{0x5601, 0, &mqc_states[30], &mqc_states[29]},
	{0x5601, 1, &mqc_states[31], &mqc_states[28]},
	{0x5401, 0, &mqc_states[32], &mqc_states[28]},
	{0x5401, 1, &mqc_states[33], &mqc_states[29]},
	{0x5101, 0, &mqc_states[34], &mqc_states[30]},
	{0x5101, 1, &mqc_states[35], &mqc_states[31]},
	{0x4801, 0, &mqc_states[36], &mqc_states[32]},
	{0x4801, 1, &mqc_states[37], &mqc_states[33]},
	{0x3801, 0, &mqc_states[38], &mqc_states[34]},
	{0x3801, 1, &mqc_states[39], &mqc_states[35]},
	{0x3401, 0, &mqc_states[40], &mqc_states[36]},
	{0x3401, 1, &mqc_states[41], &mqc_states[37]},
	{0x3001, 0, &mqc_states[42], &mqc_states[38]},
	{0x3001, 1, &mqc_states[43], &mqc_states[39]},
	{0x2801, 0, &mqc_states[44], &mqc_states[38]},
	{0x2801, 1, &mqc_states[45], &mqc_states[39]},
	{0x2401, 0, &mqc_states[46], &mqc_states[40]},
	{0x2401, 1, &mqc_states[47], &mqc_states[41]},
	{0x2201, 0, &mqc_states[48], &mqc_states[42]},
	{0x2201, 1, &mqc_states[49], &mqc_states[43]},
	{0x1c01, 0, &mqc_states[50], &mqc_states[44]},
	{0x1c01, 1, &mqc_states[51], &mqc_states[45]},
	{0x1801, 0, &mqc_states[52], &mqc_states[46]},
	{0x1801, 1, &mqc_states[53], &mqc_states[47]},
	{0x1601, 0, &mqc_states[54], &mqc_states[48]},
	{0x1601, 1, &mqc_states[55], &mqc_states[49]},
	{0x1401, 0, &mqc_states[56], &mqc_states[50]},
	{0x1401, 1, &mqc_states[57], &mqc_states[51]},
	{0x1201, 0, &mqc_states[58], &mqc_states[52]},
	{0x1201, 1, &mqc_states[59], &mqc_states[53]},
	{0x1101, 0, &mqc_states[60], &mqc_states[54]},
	{0x1101, 1, &mqc_states[61], &mqc_states[55]},
	{0x0ac1, 0, &mqc_states[62], &mqc_states[56]},
	{0x0ac1, 1, &mqc_states[63], &mqc_states[57]},
	{0x09c1, 0, &mqc_states[64], &mqc_states[58]},
	{0x09c1, 1, &mqc_states[65], &mqc_states[59]},
	{0x08a1, 0, &mqc_states[66], &mqc_states[60]},
	{0x08a1, 1, &mqc_states[67], &mqc_states[61]},
	{0x0521, 0, &mqc_states[68], &mqc_states[62]},
	{0x0521, 1, &mqc_states[69], &mqc_states[63]},
	{0x0441, 0, &mqc_states[70], &mqc_states[64]},
	{0x0441, 1, &mqc_states[71], &mqc_states[65]},
	{0x02a1, 0, &mqc_states[72], &mqc_states[66]},
	{0x02a1, 1, &mqc_states[73], &mqc_states[67]},
	{0x0221, 0, &mqc_states[74], &mqc_states[68]},
	{0x0221, 1, &mqc_states[75], &mqc_states[69]},
	{0x0141, 0, &mqc_states[76], &mqc_states[70]},
	{0x0141, 1, &mqc_states[77], &mqc_states[71]},
	{0x0111, 0, &mqc_states[78], &mqc_states[72]},
	{0x0111, 1, &mqc_states[79], &mqc_states[73]},
	{0x0085, 0, &mqc_states[80], &mqc_states[74]},
	{0x0085, 1, &mqc_states[81], &mqc_states[75]},
	{0x0049, 0, &mqc_states[82], &mqc_states[76]},
	{0x0049, 1, &mqc_states[83], &mqc_states[77]},
	{0x0025, 0, &mqc_states[84], &mqc_states[78]},
	{0x0025, 1, &mqc_states[85], &mqc_states[79]},
	{0x0015, 0, &mqc_states[86], &mqc_states[80]},
	{0x0015, 1, &mqc_states[87], &mqc_states[81]},
	{0x0009, 0, &mqc_states[88], &mqc_states[82]},
	{0x0009, 1, &mqc_states[89], &mqc_states[83]},
	{0x0005, 0, &mqc_states[90], &mqc_states[84]},
	{0x0005, 1, &mqc_states[91], &mqc_states[85]},
	{0x0001, 0, &mqc_states[90], &mqc_states[86]},
	{0x0001, 1, &mqc_states[91], &mqc_states[87]},
	{0x5601, 0, &mqc_states[92], &mqc_states[92]},
	{0x5601, 1, &mqc_states[93], &mqc_states[93]},
	};

	#define MQC_NUMCTXS 32

	unsigned int mqc_c;
	unsigned int mqc_a;
	unsigned int mqc_ct;
	unsigned char *mqc_bp;
	unsigned char *mqc_start;
	unsigned char *mqc_end;
	mqc_state_t *mqc_ctxs[MQC_NUMCTXS];
	mqc_state_t **mqc_curctx;

	/* <summary> */
	/* Return the number of bytes already encoded. */
	/* </summary> */
	int mqc_numbytes()
	{
	return mqc_bp - mqc_start;
	}

	/* <summary> */
	/* Output a byte, doing bit-stuffing if necessary. */
	/* After a 0xff byte, the next byte must be smaller than 0x90 */
	/* </summary> */
	void mqc_byteout()
	{
	if (*mqc_bp == 0xff) {
	mqc_bp++;
	*mqc_bp = mqc_c >> 20;
	mqc_c &= 0xfffff;
	mqc_ct = 7;
	} else {
	if ((mqc_c & 0x8000000) == 0) { /* ((mqc_c&0x8000000)==0) CHANGE */
	mqc_bp++;
	*mqc_bp = mqc_c >> 19;
	mqc_c &= 0x7ffff;
	mqc_ct = 8;
	} else {
	(*mqc_bp)++;
	if (*mqc_bp == 0xff) {
	mqc_c &= 0x7ffffff;
	mqc_bp++;
	*mqc_bp = mqc_c >> 20;
	mqc_c &= 0xfffff;
	mqc_ct = 7;
	} else {
	mqc_bp++;
	*mqc_bp = mqc_c >> 19;
	mqc_c &= 0x7ffff;
	mqc_ct = 8;
	}
	}
	}
	}

	/* <summary> */
	/* Renormalize mqc_a and mqc_c while encoding, so that mqc_a stays between 0x8000 and 0x10000 */
	/* </summary> */
	void mqc_renorme()
	{
	do {
	mqc_a <<= 1;
	mqc_c <<= 1;
	mqc_ct--;
	if (mqc_ct == 0) {
	mqc_byteout();
	}
	} while ((mqc_a & 0x8000) == 0);
	}

	/* <summary> */
	/* Encode the most probable symbol. */
	/* </summary> */
	void mqc_codemps()
	{
	mqc_a -= (*mqc_curctx)->qeval;
	if ((mqc_a & 0x8000) == 0) {
	if (mqc_a < (*mqc_curctx)->qeval) {
	mqc_a = (*mqc_curctx)->qeval;
	} else {
	mqc_c += (*mqc_curctx)->qeval;
	}
	mqc_curctx = (mqc_curctx)->nmps;
	mqc_renorme();
	} else {
	mqc_c += (*mqc_curctx)->qeval;
	}
	}

	/* <summary> */
	/* Encode the most least symbol. */
	/* </summary> */
	void mqc_codelps()
	{
	mqc_a -= (*mqc_curctx)->qeval;
	if (mqc_a < (*mqc_curctx)->qeval) {
	mqc_c += (*mqc_curctx)->qeval;
	} else {
	mqc_a = (*mqc_curctx)->qeval;
	}
	mqc_curctx = (mqc_curctx)->nlps;
	mqc_renorme();
	}

	/* <summary> */
	/* Initialize encoder. */
	/* </summary> */
	/* <param name="bp">Output buffer.</param> */
	void mqc_init_enc(unsigned char *bp)
	{
	mqc_setcurctx(0);
	mqc_a = 0x8000;
	mqc_c = 0;
	mqc_bp = bp - 1;
	mqc_ct = 12;
	if (*mqc_bp == 0xff) {
	mqc_ct = 13;
	}
	mqc_start = bp;
	}

	/* <summary> */
	/* Set current context. */
	/* </summary> */
	/* <param name="ctxno">Context number.</param> */
	void mqc_setcurctx(int ctxno)
	{
	mqc_curctx = &mqc_ctxs[ctxno];
	}

	/* <summary> */
	/* Encode a symbol using the MQ-coder. */
	/* </summary> */
	/* <param name="d"> The symbol to be encoded (0 or 1).</param> */
	void mqc_encode(int d)
	{
	if ((*mqc_curctx)->mps == d) {
	mqc_codemps();
	} else {
	mqc_codelps();
	}
	}

	/* <summary> */
	/* Fill mqc_c with 1's for flushing */
	/* </summary> */
	void mqc_setbits()
	{
	unsigned int tempc = mqc_c + mqc_a;
	mqc_c \|= 0xffff;
	if (mqc_c >= tempc) {
	mqc_c -= 0x8000;
	}
	}

	/* <summary> */
	/* Flush encoded data. */
	/* </summary> */
	void mqc_flush()
	{
	mqc_setbits();
	mqc_c <<= mqc_ct;
	mqc_byteout();
	mqc_c <<= mqc_ct;
	mqc_byteout();

	if (*mqc_bp != 0xff) {
	mqc_bp++;
	}
	}

	/* <summary> */
	/* not fully implemented and tested !! */
	/* BYPASS mode switch, initialization operation */
	/* JPEG 2000 p 505 */
	/* </summary> */
	void mqc_bypass_init_enc()
	{
	mqc_c = 0;
	mqc_ct = 8;
	/if (mqc_bp == 0xff) {
	mqc_ct = 7;
	}*/
	}

	/* <summary> */
	/* not fully implemented and tested !! */
	/* BYPASS mode switch, coding operation */
	/* JPEG 2000 p 505 */
	/* </summary> */
	void mqc_bypass_enc(int d)
	{
	mqc_ct--;
	mqc_c = mqc_c + (d << mqc_ct);
	if (mqc_ct == 0)
	{
	mqc_bp++;
	*mqc_bp = mqc_c;
	mqc_ct = 8;
	if (*mqc_bp == 0xff) {
	mqc_ct = 7;
	}
	mqc_c = 0;
	}
	}

	/* <summary> */
	/* not fully implemented and tested !! */
	/* BYPASS mode switch, flush operation */
	/* </summary> */
	int mqc_bypass_flush_enc()
	{
	unsigned char bit_padding;

	bit_padding = 0;

	if (mqc_ct != 0) {
	while (mqc_ct > 0) {
	mqc_ct--;
	mqc_c += bit_padding << mqc_ct;
	bit_padding = (bit_padding + 1) & 0x01;
	}
	mqc_bp++;
	*mqc_bp = mqc_c;
	mqc_ct = 8;
	mqc_c = 0;
	}

	return 1;
	}

	/* <summary> */
	/* RESET mode switch */
	/* </summary> */
	void mqc_reset_enc()
	{
	mqc_resetstates();
	mqc_setstate(18, 0, 46);
	mqc_setstate(0, 0, 3);
	mqc_setstate(1, 0, 4);
	}

	/* <summary> */
	/* mode switch RESTART (TERMALL) */
	/* </summary> */
	int mqc_restart_enc()
	{
	int correction = 1;

	/* <flush part> */
	int n = 27 - 15 - mqc_ct;
	mqc_c <<= mqc_ct;
	while (n > 0) {
	mqc_byteout();
	n -= mqc_ct;
	mqc_c <<= mqc_ct;
	}
	mqc_byteout();

	return correction;
	}

	/* <summary> */
	/* mode switch RESTART (TERMALL) reinitialisation */
	/* </summary> */
	void mqc_restart_init_enc()
	{
	/* <Re-init part> */
	mqc_setcurctx(0);
	mqc_a = 0x8000;
	mqc_c = 0;
	mqc_ct = 12;
	mqc_bp--;
	if (*mqc_bp == 0xff) {
	mqc_ct = 13;
	}
	}


	/* <summary> */
	/* ERTERM mode switch */
	/* </summary> */
	void mqc_erterm_enc()
	{
	int k = 11 - mqc_ct + 1;

	while (k > 0) {
	mqc_c <<= mqc_ct;
	mqc_ct = 0;
	mqc_byteout();
	k -= mqc_ct;
	}

	if (*mqc_bp != 0xff) {
	mqc_byteout();
	}
	}

	/* <summary> */
	/* SEGMARK mode switch (SEGSYM) */
	/* </summary> */
	void mqc_segmark_enc()
	{
	int i;
	mqc_setcurctx(18);

	for (i = 1; i < 5; i++) {
	mqc_encode(i % 2);
	}
	}

	/* <summary> */
	/* </summary> */
	int mqc_mpsexchange()
	{
	int d;
	if (mqc_a < (*mqc_curctx)->qeval) {
	d = 1 - (*mqc_curctx)->mps;
	mqc_curctx = (mqc_curctx)->nlps;
	} else {
	d = (*mqc_curctx)->mps;
	mqc_curctx = (mqc_curctx)->nmps;
	}
	return d;
	}

	/* <summary> */
	/* </summary> */
	int mqc_lpsexchange()
	{
	int d;
	if (mqc_a < (*mqc_curctx)->qeval) {
	mqc_a = (*mqc_curctx)->qeval;
	d = (*mqc_curctx)->mps;
	mqc_curctx = (mqc_curctx)->nmps;
	} else {
	mqc_a = (*mqc_curctx)->qeval;
	d = 1 - (*mqc_curctx)->mps;
	mqc_curctx = (mqc_curctx)->nlps;
	}
	return d;
	}

	/* <summary> */
	/* Input a byte. */
	/* </summary> */
	void mqc_bytein()
	{
	if (mqc_bp != mqc_end) {
	unsigned int c;
	if (mqc_bp + 1 != mqc_end) {
	c = *(mqc_bp + 1);
	} else {
	c = 0xff;
	}
	if (*mqc_bp == 0xff) {
	if (c > 0x8f) {
	mqc_c += 0xff00;
	mqc_ct = 8;
	} else {
	mqc_bp++;
	mqc_c += c << 9;
	mqc_ct = 7;
	}
	} else {
	mqc_bp++;
	mqc_c += c << 8;
	mqc_ct = 8;
	}
	} else {
	mqc_c += 0xff00;
	mqc_ct = 8;
	}
	}

	/* <summary> */
	/* Renormalize mqc_a and mqc_c while decoding. */
	/* </summary> */
	void mqc_renormd()
	{
	do {
	if (mqc_ct == 0) {
	mqc_bytein();
	}
	mqc_a <<= 1;
	mqc_c <<= 1;
	mqc_ct--;
	} while (mqc_a < 0x8000);
	}

	/* <summary> */
	/* Initialize decoder. */
	/* </summary> */
	void mqc_init_dec(unsigned char *bp, int len)
	{
	mqc_setcurctx(0);
	mqc_start = bp;
	mqc_end = bp + len;
	mqc_bp = bp;
	mqc_c = *mqc_bp << 16;
	mqc_bytein();
	mqc_c <<= 7;
	mqc_ct -= 7;
	mqc_a = 0x8000;
	}

	/* <summary> */
	/* Decode a symbol. */
	/* </summary> */
	int mqc_decode()
	{
	int d;
	mqc_a -= (*mqc_curctx)->qeval;
	if ((mqc_c >> 16) < (*mqc_curctx)->qeval) {
	d = mqc_lpsexchange();
	mqc_renormd();
	} else {
	mqc_c -= (*mqc_curctx)->qeval << 16;
	if ((mqc_a & 0x8000) == 0) {
	d = mqc_mpsexchange();
	mqc_renormd();
	} else {
	d = (*mqc_curctx)->mps;
	}
	}
	return d;
	}

	/* <summary> */
	/* Reset states of all contexts. */
	/* </summary> */
	void mqc_resetstates()
	{
	int i;
	for (i = 0; i < MQC_NUMCTXS; i++) {
	mqc_ctxs[i] = mqc_states;
	}
	}

	/* <summary> */
	/* Set the state for a context. */
	/* </summary> */
	/* <param name="ctxno">Context number</param> */
	/* <param name="msb">Most significant bit</param> */
	/* <param name="prob">Index to the probability of symbols</param> */
	void mqc_setstate(int ctxno, int msb, int prob)
	{
	mqc_ctxs[ctxno] = &mqc_states[msb + (prob << 1)];
	}