| /* |
| * The copyright in this software is being made available under the 2-clauses |
| * BSD License, included below. This software may be subject to other third |
| * party and contributor rights, including patent rights, and no such rights |
| * are granted under this license. |
| * |
| * Copyright (c) 2002-2014, Universite catholique de Louvain (UCL), Belgium |
| * Copyright (c) 2002-2014, Professor Benoit Macq |
| * Copyright (c) 2001-2003, David Janssens |
| * Copyright (c) 2002-2003, Yannick Verschueren |
| * Copyright (c) 2003-2007, Francois-Olivier Devaux |
| * Copyright (c) 2003-2014, Antonin Descampe |
| * Copyright (c) 2005, Herve Drolon, FreeImage Team |
| * Copyright (c) 2008, Jerome Fimes, Communications & Systemes <jerome.fimes@c-s.fr> |
| * 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 "opj_includes.h" |
| |
| #include <assert.h> |
| |
| /** @defgroup MQC MQC - Implementation of an MQ-Coder */ |
| /*@{*/ |
| |
| /** @name Local static functions */ |
| /*@{*/ |
| |
| /** |
| Output a byte, doing bit-stuffing if necessary. |
| After a 0xff byte, the next byte must be smaller than 0x90. |
| @param mqc MQC handle |
| */ |
| static void opj_mqc_byteout(opj_mqc_t *mqc); |
| /** |
| Renormalize mqc->a and mqc->c while encoding, so that mqc->a stays between 0x8000 and 0x10000 |
| @param mqc MQC handle |
| */ |
| static void opj_mqc_renorme(opj_mqc_t *mqc); |
| /** |
| Encode the most probable symbol |
| @param mqc MQC handle |
| */ |
| static void opj_mqc_codemps(opj_mqc_t *mqc); |
| /** |
| Encode the most least symbol |
| @param mqc MQC handle |
| */ |
| static void opj_mqc_codelps(opj_mqc_t *mqc); |
| /** |
| Fill mqc->c with 1's for flushing |
| @param mqc MQC handle |
| */ |
| static void opj_mqc_setbits(opj_mqc_t *mqc); |
| /*@}*/ |
| |
| /*@}*/ |
| |
| /* <summary> */ |
| /* This array defines all the possible states for a context. */ |
| /* </summary> */ |
| static const opj_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]}, |
| }; |
| |
| /* |
| ========================================================== |
| local functions |
| ========================================================== |
| */ |
| |
| static void opj_mqc_byteout(opj_mqc_t *mqc) |
| { |
| /* bp is initialized to start - 1 in opj_mqc_init_enc() */ |
| /* but this is safe, see opj_tcd_code_block_enc_allocate_data() */ |
| assert(mqc->bp >= mqc->start - 1); |
| if (*mqc->bp == 0xff) { |
| mqc->bp++; |
| *mqc->bp = (OPJ_BYTE)(mqc->c >> 20); |
| mqc->c &= 0xfffff; |
| mqc->ct = 7; |
| } else { |
| if ((mqc->c & 0x8000000) == 0) { |
| mqc->bp++; |
| *mqc->bp = (OPJ_BYTE)(mqc->c >> 19); |
| mqc->c &= 0x7ffff; |
| mqc->ct = 8; |
| } else { |
| (*mqc->bp)++; |
| if (*mqc->bp == 0xff) { |
| mqc->c &= 0x7ffffff; |
| mqc->bp++; |
| *mqc->bp = (OPJ_BYTE)(mqc->c >> 20); |
| mqc->c &= 0xfffff; |
| mqc->ct = 7; |
| } else { |
| mqc->bp++; |
| *mqc->bp = (OPJ_BYTE)(mqc->c >> 19); |
| mqc->c &= 0x7ffff; |
| mqc->ct = 8; |
| } |
| } |
| } |
| } |
| |
| static void opj_mqc_renorme(opj_mqc_t *mqc) |
| { |
| do { |
| mqc->a <<= 1; |
| mqc->c <<= 1; |
| mqc->ct--; |
| if (mqc->ct == 0) { |
| opj_mqc_byteout(mqc); |
| } |
| } while ((mqc->a & 0x8000) == 0); |
| } |
| |
| static void opj_mqc_codemps(opj_mqc_t *mqc) |
| { |
| 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; |
| opj_mqc_renorme(mqc); |
| } else { |
| mqc->c += (*mqc->curctx)->qeval; |
| } |
| } |
| |
| static void opj_mqc_codelps(opj_mqc_t *mqc) |
| { |
| 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; |
| opj_mqc_renorme(mqc); |
| } |
| |
| static void opj_mqc_setbits(opj_mqc_t *mqc) |
| { |
| OPJ_UINT32 tempc = mqc->c + mqc->a; |
| mqc->c |= 0xffff; |
| if (mqc->c >= tempc) { |
| mqc->c -= 0x8000; |
| } |
| } |
| |
| /* |
| ========================================================== |
| MQ-Coder interface |
| ========================================================== |
| */ |
| |
| OPJ_UINT32 opj_mqc_numbytes(opj_mqc_t *mqc) |
| { |
| const ptrdiff_t diff = mqc->bp - mqc->start; |
| #if 0 |
| assert(diff <= 0xffffffff && diff >= 0); /* UINT32_MAX */ |
| #endif |
| return (OPJ_UINT32)diff; |
| } |
| |
| void opj_mqc_init_enc(opj_mqc_t *mqc, OPJ_BYTE *bp) |
| { |
| /* To avoid the curctx pointer to be dangling, but not strictly */ |
| /* required as the current context is always set before encoding */ |
| opj_mqc_setcurctx(mqc, 0); |
| |
| /* As specified in Figure C.10 - Initialization of the encoder */ |
| /* (C.2.8 Initialization of the encoder (INITENC)) */ |
| mqc->a = 0x8000; |
| mqc->c = 0; |
| /* Yes, we point before the start of the buffer, but this is safe */ |
| /* given opj_tcd_code_block_enc_allocate_data() */ |
| mqc->bp = bp - 1; |
| mqc->ct = 12; |
| /* At this point we should test *(mqc->bp) against 0xFF, but this is not */ |
| /* necessary, as this is only used at the beginning of the code block */ |
| /* and our initial fake byte is set at 0 */ |
| assert(*(mqc->bp) != 0xff); |
| |
| mqc->start = bp; |
| mqc->end_of_byte_stream_counter = 0; |
| } |
| |
| void opj_mqc_encode(opj_mqc_t *mqc, OPJ_UINT32 d) |
| { |
| if ((*mqc->curctx)->mps == d) { |
| opj_mqc_codemps(mqc); |
| } else { |
| opj_mqc_codelps(mqc); |
| } |
| } |
| |
| void opj_mqc_flush(opj_mqc_t *mqc) |
| { |
| /* C.2.9 Termination of coding (FLUSH) */ |
| /* Figure C.11 – FLUSH procedure */ |
| opj_mqc_setbits(mqc); |
| mqc->c <<= mqc->ct; |
| opj_mqc_byteout(mqc); |
| mqc->c <<= mqc->ct; |
| opj_mqc_byteout(mqc); |
| |
| /* It is forbidden that a coding pass ends with 0xff */ |
| if (*mqc->bp != 0xff) { |
| /* Advance pointer so that opj_mqc_numbytes() returns a valid value */ |
| mqc->bp++; |
| } |
| } |
| |
| #define BYPASS_CT_INIT 0xDEADBEEF |
| |
| void opj_mqc_bypass_init_enc(opj_mqc_t *mqc) |
| { |
| /* This function is normally called after at least one opj_mqc_flush() */ |
| /* which will have advance mqc->bp by at least 2 bytes beyond its */ |
| /* initial position */ |
| assert(mqc->bp >= mqc->start); |
| mqc->c = 0; |
| /* in theory we should initialize to 8, but use this special value */ |
| /* as a hint that opj_mqc_bypass_enc() has never been called, so */ |
| /* as to avoid the 0xff 0x7f elimination trick in opj_mqc_bypass_flush_enc() */ |
| /* to trigger when we don't have output any bit during this bypass sequence */ |
| /* Any value > 8 will do */ |
| mqc->ct = BYPASS_CT_INIT; |
| /* Given that we are called after opj_mqc_flush(), the previous byte */ |
| /* cannot be 0xff. */ |
| assert(mqc->bp[-1] != 0xff); |
| } |
| |
| void opj_mqc_bypass_enc(opj_mqc_t *mqc, OPJ_UINT32 d) |
| { |
| if (mqc->ct == BYPASS_CT_INIT) { |
| mqc->ct = 8; |
| } |
| mqc->ct--; |
| mqc->c = mqc->c + (d << mqc->ct); |
| if (mqc->ct == 0) { |
| *mqc->bp = (OPJ_BYTE)mqc->c; |
| mqc->ct = 8; |
| /* If the previous byte was 0xff, make sure that the next msb is 0 */ |
| if (*mqc->bp == 0xff) { |
| mqc->ct = 7; |
| } |
| mqc->bp++; |
| mqc->c = 0; |
| } |
| } |
| |
| OPJ_UINT32 opj_mqc_bypass_get_extra_bytes(opj_mqc_t *mqc, OPJ_BOOL erterm) |
| { |
| return (mqc->ct < 7 || |
| (mqc->ct == 7 && (erterm || mqc->bp[-1] != 0xff))) ? 1 : 0; |
| } |
| |
| void opj_mqc_bypass_flush_enc(opj_mqc_t *mqc, OPJ_BOOL erterm) |
| { |
| /* Is there any bit remaining to be flushed ? */ |
| /* If the last output byte is 0xff, we can discard it, unless */ |
| /* erterm is required (I'm not completely sure why in erterm */ |
| /* we must output 0xff 0x2a if the last byte was 0xff instead of */ |
| /* discarding it, but Kakadu requires it when decoding */ |
| /* in -fussy mode) */ |
| if (mqc->ct < 7 || (mqc->ct == 7 && (erterm || mqc->bp[-1] != 0xff))) { |
| OPJ_BYTE bit_value = 0; |
| /* If so, fill the remaining lsbs with an alternating sequence of */ |
| /* 0,1,... */ |
| /* Note: it seems the standard only requires that for a ERTERM flush */ |
| /* and doesn't specify what to do for a regular BYPASS flush */ |
| while (mqc->ct > 0) { |
| mqc->ct--; |
| mqc->c += (OPJ_UINT32)(bit_value << mqc->ct); |
| bit_value = (OPJ_BYTE)(1U - bit_value); |
| } |
| *mqc->bp = (OPJ_BYTE)mqc->c; |
| /* Advance pointer so that opj_mqc_numbytes() returns a valid value */ |
| mqc->bp++; |
| } else if (mqc->ct == 7 && mqc->bp[-1] == 0xff) { |
| /* Discard last 0xff */ |
| assert(!erterm); |
| mqc->bp --; |
| } else if (mqc->ct == 8 && !erterm && |
| mqc->bp[-1] == 0x7f && mqc->bp[-2] == 0xff) { |
| /* Tiny optimization: discard terminating 0xff 0x7f since it is */ |
| /* interpreted as 0xff 0x7f [0xff 0xff] by the decoder, and given */ |
| /* the bit stuffing, in fact as 0xff 0xff [0xff ..] */ |
| /* Happens once on opj_compress -i ../MAPA.tif -o MAPA.j2k -M 1 */ |
| mqc->bp -= 2; |
| } |
| |
| assert(mqc->bp[-1] != 0xff); |
| } |
| |
| void opj_mqc_reset_enc(opj_mqc_t *mqc) |
| { |
| opj_mqc_resetstates(mqc); |
| opj_mqc_setstate(mqc, T1_CTXNO_UNI, 0, 46); |
| opj_mqc_setstate(mqc, T1_CTXNO_AGG, 0, 3); |
| opj_mqc_setstate(mqc, T1_CTXNO_ZC, 0, 4); |
| } |
| |
| #ifdef notdef |
| OPJ_UINT32 opj_mqc_restart_enc(opj_mqc_t *mqc) |
| { |
| OPJ_UINT32 correction = 1; |
| |
| /* <flush part> */ |
| OPJ_INT32 n = (OPJ_INT32)(27 - 15 - mqc->ct); |
| mqc->c <<= mqc->ct; |
| while (n > 0) { |
| opj_mqc_byteout(mqc); |
| n -= (OPJ_INT32)mqc->ct; |
| mqc->c <<= mqc->ct; |
| } |
| opj_mqc_byteout(mqc); |
| |
| return correction; |
| } |
| #endif |
| |
| void opj_mqc_restart_init_enc(opj_mqc_t *mqc) |
| { |
| /* <Re-init part> */ |
| |
| /* As specified in Figure C.10 - Initialization of the encoder */ |
| /* (C.2.8 Initialization of the encoder (INITENC)) */ |
| mqc->a = 0x8000; |
| mqc->c = 0; |
| mqc->ct = 12; |
| /* This function is normally called after at least one opj_mqc_flush() */ |
| /* which will have advance mqc->bp by at least 2 bytes beyond its */ |
| /* initial position */ |
| mqc->bp --; |
| assert(mqc->bp >= mqc->start - 1); |
| assert(*mqc->bp != 0xff); |
| if (*mqc->bp == 0xff) { |
| mqc->ct = 13; |
| } |
| } |
| |
| void opj_mqc_erterm_enc(opj_mqc_t *mqc) |
| { |
| OPJ_INT32 k = (OPJ_INT32)(11 - mqc->ct + 1); |
| |
| while (k > 0) { |
| mqc->c <<= mqc->ct; |
| mqc->ct = 0; |
| opj_mqc_byteout(mqc); |
| k -= (OPJ_INT32)mqc->ct; |
| } |
| |
| if (*mqc->bp != 0xff) { |
| opj_mqc_byteout(mqc); |
| } |
| } |
| |
| void opj_mqc_segmark_enc(opj_mqc_t *mqc) |
| { |
| OPJ_UINT32 i; |
| opj_mqc_setcurctx(mqc, 18); |
| |
| for (i = 1; i < 5; i++) { |
| opj_mqc_encode(mqc, i % 2); |
| } |
| } |
| |
| static void opj_mqc_init_dec_common(opj_mqc_t *mqc, |
| OPJ_BYTE *bp, |
| OPJ_UINT32 len, |
| OPJ_UINT32 extra_writable_bytes) |
| { |
| (void)extra_writable_bytes; |
| |
| assert(extra_writable_bytes >= OPJ_COMMON_CBLK_DATA_EXTRA); |
| mqc->start = bp; |
| mqc->end = bp + len; |
| /* Insert an artificial 0xFF 0xFF marker at end of the code block */ |
| /* data so that the bytein routines stop on it. This saves us comparing */ |
| /* the bp and end pointers */ |
| /* But before inserting it, backup th bytes we will overwrite */ |
| memcpy(mqc->backup, mqc->end, OPJ_COMMON_CBLK_DATA_EXTRA); |
| mqc->end[0] = 0xFF; |
| mqc->end[1] = 0xFF; |
| mqc->bp = bp; |
| } |
| void opj_mqc_init_dec(opj_mqc_t *mqc, OPJ_BYTE *bp, OPJ_UINT32 len, |
| OPJ_UINT32 extra_writable_bytes) |
| { |
| /* Implements ISO 15444-1 C.3.5 Initialization of the decoder (INITDEC) */ |
| /* Note: alternate "J.1 - Initialization of the software-conventions */ |
| /* decoder" has been tried, but does */ |
| /* not bring any improvement. */ |
| /* See https://github.com/uclouvain/openjpeg/issues/921 */ |
| opj_mqc_init_dec_common(mqc, bp, len, extra_writable_bytes); |
| opj_mqc_setcurctx(mqc, 0); |
| mqc->end_of_byte_stream_counter = 0; |
| if (len == 0) { |
| mqc->c = 0xff << 16; |
| } else { |
| mqc->c = (OPJ_UINT32)(*mqc->bp << 16); |
| } |
| |
| opj_mqc_bytein(mqc); |
| mqc->c <<= 7; |
| mqc->ct -= 7; |
| mqc->a = 0x8000; |
| } |
| |
| |
| void opj_mqc_raw_init_dec(opj_mqc_t *mqc, OPJ_BYTE *bp, OPJ_UINT32 len, |
| OPJ_UINT32 extra_writable_bytes) |
| { |
| opj_mqc_init_dec_common(mqc, bp, len, extra_writable_bytes); |
| mqc->c = 0; |
| mqc->ct = 0; |
| } |
| |
| |
| void opq_mqc_finish_dec(opj_mqc_t *mqc) |
| { |
| /* Restore the bytes overwritten by opj_mqc_init_dec_common() */ |
| memcpy(mqc->end, mqc->backup, OPJ_COMMON_CBLK_DATA_EXTRA); |
| } |
| |
| void opj_mqc_resetstates(opj_mqc_t *mqc) |
| { |
| OPJ_UINT32 i; |
| for (i = 0; i < MQC_NUMCTXS; i++) { |
| mqc->ctxs[i] = mqc_states; |
| } |
| } |
| |
| void opj_mqc_setstate(opj_mqc_t *mqc, OPJ_UINT32 ctxno, OPJ_UINT32 msb, |
| OPJ_INT32 prob) |
| { |
| mqc->ctxs[ctxno] = &mqc_states[msb + (OPJ_UINT32)(prob << 1)]; |
| } |
| |
| |