avcodec/jpeg2000dec: add support for HTJ2K block decoding

Signed-off-by: Pierre-Anthony Lemieux <pal@palemieux.com>

5 files changed, 1539 insertions, 19 deletions

diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index a1a8b8b88e..b0971ce833 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -469,7 +469,7 @@ OBJS-$(CONFIG_JACOSUB_DECODER)         += jacosubdec.o ass.o
 OBJS-$(CONFIG_JPEG2000_ENCODER)        += j2kenc.o mqcenc.o mqc.o jpeg2000.o \
                                           jpeg2000dwt.o
 OBJS-$(CONFIG_JPEG2000_DECODER)        += jpeg2000dec.o jpeg2000.o jpeg2000dsp.o \
-                                          jpeg2000dwt.o mqcdec.o mqc.o
+                                          jpeg2000dwt.o mqcdec.o mqc.o jpeg2000htdec.o
 OBJS-$(CONFIG_JPEGLS_DECODER)          += jpeglsdec.o jpegls.o
 OBJS-$(CONFIG_JPEGLS_ENCODER)          += jpeglsenc.o jpegls.o
 OBJS-$(CONFIG_JV_DECODER)              += jvdec.o
diff --git a/libavcodec/jpeg2000.h b/libavcodec/jpeg2000.h
index e5ecb4cbf9..d004c08f10 100644
--- a/libavcodec/jpeg2000.h
+++ b/libavcodec/jpeg2000.h
@@ -111,7 +111,7 @@ enum Jpeg2000Quantsty { // quantization style
 #define JPEG2000_CSTY_SOP       0x02 // SOP marker present
 #define JPEG2000_CSTY_EPH       0x04 // EPH marker present
 #define JPEG2000_CTSY_HTJ2K_F   0x40 // Only HT code-blocks (Rec. ITU-T T.814 | ISO/IEC 15444-15) are present
-#define JPEG2000_CTSY_HTJ2K_M   0xC0 // HT code blocks (Rec. ITU-T T.814 | ISO/IEC 15444-15) can be present
+#define JPEG2000_CTSY_HTJ2K_M   0xC0 // HT code-blocks (Rec. ITU-T T.814 | ISO/IEC 15444-15) can be present
 
 // Progression orders
 #define JPEG2000_PGOD_LRCP      0x00  // Layer-resolution level-component-position progression
@@ -189,6 +189,9 @@ typedef struct Jpeg2000Cblk {
     Jpeg2000Pass *passes;
     Jpeg2000Layer *layers;
     int coord[2][2]; // border coordinates {{x0, x1}, {y0, y1}}
+    /* specific to HT code-blocks */
+    int zbp;
+    int pass_lengths[2];
 } Jpeg2000Cblk; // code block
 
 typedef struct Jpeg2000Prec {
diff --git a/libavcodec/jpeg2000dec.c b/libavcodec/jpeg2000dec.c
index 2319efdd77..40e6650110 100644
--- a/libavcodec/jpeg2000dec.c
+++ b/libavcodec/jpeg2000dec.c
@@ -43,6 +43,7 @@
 #include "jpeg2000dsp.h"
 #include "profiles.h"
 #include "jpeg2000dec.h"
+#include "jpeg2000htdec.h"
 
 #define JP2_SIG_TYPE    0x6A502020
 #define JP2_SIG_VALUE   0x0D0A870A
@@ -440,12 +441,12 @@ static int get_cox(Jpeg2000DecoderContext *s, Jpeg2000CodingStyle *c)
     c->cblk_style = bytestream2_get_byteu(&s->g);
     if (c->cblk_style != 0) { // cblk style
         if (c->cblk_style & JPEG2000_CTSY_HTJ2K_M || c->cblk_style & JPEG2000_CTSY_HTJ2K_F) {
-            av_log(s->avctx, AV_LOG_ERROR, "Support for High throughput JPEG 2000 is not yet available\n");
-            return AVERROR_PATCHWELCOME;
+            av_log(s->avctx,AV_LOG_TRACE,"High Throughput jpeg 2000 codestream.\n");
+        } else {
+            av_log(s->avctx, AV_LOG_WARNING, "extra cblk styles %X\n", c->cblk_style);
+            if (c->cblk_style & JPEG2000_CBLK_BYPASS)
+                av_log(s->avctx, AV_LOG_WARNING, "Selective arithmetic coding bypass\n");
         }
-        av_log(s->avctx, AV_LOG_WARNING, "extra cblk styles %X\n", c->cblk_style);
-        if (c->cblk_style & JPEG2000_CBLK_BYPASS)
-            av_log(s->avctx, AV_LOG_WARNING, "Selective arithmetic coding bypass\n");
     }
     c->transform = bytestream2_get_byteu(&s->g); // DWT transformation type
     /* set integer 9/7 DWT in case of BITEXACT flag */
@@ -1070,13 +1071,15 @@ static int jpeg2000_decode_packet(Jpeg2000DecoderContext *s, Jpeg2000Tile *tile,
                 return incl;
 
             if (!cblk->npasses) {
-                int v = expn[bandno] + numgbits - 1 -
-                        tag_tree_decode(s, prec->zerobits + cblkno, 100);
+                int zbp = tag_tree_decode(s, prec->zerobits + cblkno, 100);
+                int v = expn[bandno] + numgbits - 1 - zbp;
+
                 if (v < 0 || v > 30) {
                     av_log(s->avctx, AV_LOG_ERROR,
                            "nonzerobits %d invalid or unsupported\n", v);
                     return AVERROR_INVALIDDATA;
                 }
+                cblk->zbp = zbp;
                 cblk->nonzerobits = v;
             }
             if ((newpasses = getnpasses(s)) < 0)
@@ -1117,8 +1120,23 @@ static int jpeg2000_decode_packet(Jpeg2000DecoderContext *s, Jpeg2000Tile *tile,
                     }
                 }
 
-                if ((ret = get_bits(s, av_log2(newpasses1) + cblk->lblock)) < 0)
-                    return ret;
+                if (newpasses > 1 && (codsty->cblk_style & JPEG2000_CTSY_HTJ2K_F)) {
+                    // Retrieve pass lengths for each pass
+                    int href_passes =  (cblk->npasses + newpasses - 1) % 3;
+                    int eb = av_log2(newpasses - href_passes);
+                    int extra_bit = newpasses > 2 ? 1 : 0;
+                    if ((ret = get_bits(s, llen + eb + 3)) < 0)
+                        return ret;
+                    cblk->pass_lengths[0] = ret;
+                    if ((ret = get_bits(s, llen + 3 + extra_bit)) < 0)
+                        return ret;
+                    cblk->pass_lengths[1] = ret;
+                    ret = cblk->pass_lengths[0] + cblk->pass_lengths[1];
+                } else {
+                    if ((ret = get_bits(s, av_log2(newpasses1) + cblk->lblock)) < 0)
+                        return ret;
+                    cblk->pass_lengths[0] = ret;
+                }
                 if (ret > cblk->data_allocated) {
                     size_t new_size = FFMAX(2*cblk->data_allocated, ret);
                     void *new = av_realloc(cblk->data, new_size);
@@ -1867,9 +1885,12 @@ static inline void tile_codeblocks(const Jpeg2000DecoderContext *s, Jpeg2000Tile
 
     /* Loop on tile components */
     for (compno = 0; compno < s->ncomponents; compno++) {
-        Jpeg2000Component *comp     = tile->comp + compno;
-        Jpeg2000CodingStyle *codsty = tile->codsty + compno;
+        Jpeg2000Component *comp      = tile->comp   + compno;
+        Jpeg2000CodingStyle *codsty  = tile->codsty + compno;
+        Jpeg2000QuantStyle *quantsty = tile->qntsty + compno;
+
         int coded = 0;
+        int subbandno = 0;
 
         t1.stride = (1<<codsty->log2_cblk_width) + 2;
 
@@ -1877,7 +1898,7 @@ static inline void tile_codeblocks(const Jpeg2000DecoderContext *s, Jpeg2000Tile
         for (reslevelno = 0; reslevelno < codsty->nreslevels2decode; reslevelno++) {
             Jpeg2000ResLevel *rlevel = comp->reslevel + reslevelno;
             /* Loop on bands */
-            for (bandno = 0; bandno < rlevel->nbands; bandno++) {
+            for (bandno = 0; bandno < rlevel->nbands; bandno++, subbandno++) {
                 int nb_precincts, precno;
                 Jpeg2000Band *band = rlevel->band + bandno;
                 int cblkno = 0, bandpos;
@@ -1897,12 +1918,23 @@ static inline void tile_codeblocks(const Jpeg2000DecoderContext *s, Jpeg2000Tile
                     for (cblkno = 0;
                          cblkno < prec->nb_codeblocks_width * prec->nb_codeblocks_height;
                          cblkno++) {
-                        int x, y;
+                        int x, y, ret;
+                        /* See Rec. ITU-T T.800, Equation E-2 */
+                        int magp = quantsty->expn[subbandno] + quantsty->nguardbits - 1;
+
                         Jpeg2000Cblk *cblk = prec->cblk + cblkno;
-                        int ret = decode_cblk(s, codsty, &t1, cblk,
-                                    cblk->coord[0][1] - cblk->coord[0][0],
-                                    cblk->coord[1][1] - cblk->coord[1][0],
-                                    bandpos, comp->roi_shift);
+
+                        if (codsty->cblk_style & JPEG2000_CTSY_HTJ2K_F)
+                            ret = ff_jpeg2000_decode_htj2k(s, codsty, &t1, cblk,
+                                                           cblk->coord[0][1] - cblk->coord[0][0],
+                                                           cblk->coord[1][1] - cblk->coord[1][0],
+                                                           magp, comp->roi_shift);
+                        else
+                            ret = decode_cblk(s, codsty, &t1, cblk,
+                                              cblk->coord[0][1] - cblk->coord[0][0],
+                                              cblk->coord[1][1] - cblk->coord[1][0],
+                                              bandpos, comp->roi_shift);
+
                         if (ret)
                             coded = 1;
                         else
diff --git a/libavcodec/jpeg2000htdec.c b/libavcodec/jpeg2000htdec.c
new file mode 100644
index 0000000000..51cd96e0f1
--- /dev/null
+++ b/libavcodec/jpeg2000htdec.c
@@ -0,0 +1,1451 @@
+/*
+ * Copyright (c) 2022 Caleb Etemesi <etemesicaleb@gmail.com>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/*
+ * Copyright 2019 - 2021, Osamu Watanabe
+ *
+ * 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.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software without
+ *    specific prior written permission.
+ *
+ * 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 HOLDER 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 <stdint.h>
+#include "libavutil/attributes.h"
+#include "libavutil/common.h"
+#include "libavutil/avassert.h"
+#include "jpeg2000htdec.h"
+#include "jpeg2000.h"
+#include "jpeg2000dec.h"
+
+#define J2K_Q1 0
+#define J2K_Q2 1
+
+#define HT_SHIFT_SIGMA 0
+#define HT_SHIFT_SCAN 4
+#define HT_SHIFT_REF 3
+#define HT_SHIFT_REF_IND 2
+
+/* See Rec. ITU-T T.800, Table 2 */
+const static uint8_t mel_e[13] = { 0, 0, 0, 1, 1, 1, 2, 2, 2, 3, 3, 4, 5 };
+
+static const uint16_t dec_cxt_vlc_table1[1024];
+static const uint16_t dec_cxt_vlc_table0[1024];
+
+typedef struct StateVars {
+    int32_t pos;
+    uint32_t bits;
+    uint32_t tmp;
+    uint32_t last;
+    uint8_t bits_left;
+    uint64_t bit_buf;
+} StateVars;
+
+typedef struct MelDecoderState {
+    uint8_t k;
+    uint8_t run;
+    uint8_t one;
+} MelDecoderState;
+
+/**
+ *  Given a precomputed c, checks whether n % d == 0. c is precomputed from d
+ *  using precompute_c().
+ */
+av_always_inline
+static uint32_t is_divisible(uint32_t n, uint64_t c)
+{
+    return n * c <= c - 1;
+}
+
+/**
+ *  Precompute the number c used by is_divisible().
+ */
+av_always_inline
+static uint64_t precompute_c(uint32_t d)
+{
+    return 1 + (0xffffffffffffffffull / d);
+}
+
+static void jpeg2000_init_zero(StateVars *s)
+{
+    s->bits_left = 0;
+    s->bit_buf   = 0;
+    s->tmp       = 0;
+    s->bits      = 0;
+    s->pos       = 0;
+    s->last      = 0;
+}
+
+static void jpeg2000_init_mel(StateVars *s, uint32_t Pcup)
+{
+    jpeg2000_init_zero(s);
+    s->pos = Pcup;
+}
+
+static void jpeg2000_init_mag_ref(StateVars *s, uint32_t Lref)
+{
+    s->pos       = Lref - 2;
+    s->bits      = 0;
+    s->last      = 0xFF;
+    s->tmp       = 0;
+    s->bits_left = 0;
+    s->bit_buf   = 0;
+}
+
+static void jpeg2000_init_mel_decoder(MelDecoderState *mel_state)
+{
+    mel_state->k   = 0;
+    mel_state->run = 0;
+    mel_state->one = 0;
+}
+
+/**
+ * Refill the buffer backwards in little endian while skipping over stuffing
+ * bits. Stuffing bits are those that appear in the position of any byte whose
+ * LSBs are all 1's if the last consumed byte was larger than 0x8F.
+ */
+static int jpeg2000_bitbuf_refill_backwards(StateVars *buffer, const uint8_t *array)
+{
+    uint64_t tmp = 0;
+    int32_t position = buffer->pos;
+    uint32_t new_bits = 32;
+
+    if (buffer->bits_left >= 32)
+        return 0; // enough data, no need to pull in more bits
+
+    /**
+     * We are reading bytes from end to start and need to handle being close to
+     * the end. Subtracting by 4 means we will read some of the bytes of the MEL
+     * byte stream since the MEL byte stream ends at the start of the VLC byte
+     * stream. This is okay as they are masked away since we check for cases
+     * where that occurs (when the position is less than 4).
+     */
+    position -= 4;
+
+    tmp = AV_RB32(&array[position + 1]);
+
+    if (buffer->pos < 4){
+        /* mask un-needed bits if we are close to input end */
+        uint64_t mask = (1ull << (buffer->pos + 1) * 8) - 1;
+        tmp &= mask;
+    }
+
+    /**
+     *  Unstuff bits. Load a temporary byte, which precedes the position we
+     *  currently at, to ensure that we can also un-stuff if the stuffed bit is
+     *  the bottom most bits.
+     */
+    tmp <<= 8;
+    tmp |= array[buffer->pos + 1];
+
+    if ((tmp & 0x7FFF000000) > 0x7F8F000000) {
+        tmp &= 0x7FFFFFFFFF;
+        new_bits--;
+    }
+    if ((tmp & 0x007FFF0000) > 0x007F8F0000) {
+        tmp = (tmp & 0x007FFFFFFF) + ((tmp & 0xFF00000000) >> 1);
+        new_bits--;
+    }
+    if ((tmp & 0x00007FFF00) > 0x00007F8F00) {
+        tmp = (tmp & 0x00007FFFFF) + ((tmp & 0xFFFF000000) >> 1);
+        new_bits--;
+    }
+    if ((tmp & 0x0000007FFF) > 0x0000007F8F) {
+        tmp = (tmp & 0x0000007FFF) + ((tmp & 0xFFFFFF0000) >> 1);
+        new_bits--;
+    }
+
+    tmp >>= 8; // Remove temporary byte loaded
+
+    /* Add bits to the MSB of the bit buffer */
+    buffer->bit_buf |= tmp << buffer->bits_left;
+    buffer->bits_left += new_bits;
+    buffer->pos = FFMAX(0, position);
+    return 0;
+}
+
+/**
+ * Refill the bit-buffer reading new bits going forward
+ * in the stream while skipping over stuffed bits.
+ */
+static void jpeg2000_bitbuf_refill_forward(StateVars *buffer, const uint8_t *array,
+                                           uint32_t length)
+{
+    while (buffer->bits_left < 32) {
+        buffer->tmp = 0xFF;
+        buffer->bits = (buffer->last == 0xFF) ? 7 : 8;
+        if (buffer->pos <= length) {
+            buffer->tmp = array[buffer->pos];
+            buffer->pos += 1;
+            buffer->last = buffer->tmp;
+        }
+        buffer->bit_buf |= ((uint64_t) buffer->tmp) << buffer->bits_left;
+        buffer->bits_left += buffer->bits;
+    }
+}
+
+/**
+ * Drops bits from lower bits in the bit buffer. buf contains the bit buffers.
+ * nbits is the number of bits to remove.
+ */
+av_always_inline
+static void jpeg2000_bitbuf_drop_bits_lsb(StateVars *buf, uint8_t nbits)
+{
+    av_assert2(buf->bits_left >= nbits); // cannot read more bits than available
+    buf->bit_buf >>= nbits;
+    buf->bits_left -= nbits;
+}
+
+/**
+ * Get bits from the bit buffer reading them from the least significant bits
+ * moving to the most significant bits. In case there are fewer bits, refill
+ * from buf moving backwards.
+ */
+av_always_inline
+static uint64_t jpeg2000_bitbuf_get_bits_lsb(StateVars *bit_stream, uint8_t nbits,
+                                             const uint8_t *buf)
+{
+    uint64_t bits;
+    uint64_t mask = (1ull << nbits) - 1;
+    if (bit_stream->bits_left < nbits)
+        jpeg2000_bitbuf_refill_backwards(bit_stream, buf);
+    bits = bit_stream->bit_buf & mask;
+    jpeg2000_bitbuf_drop_bits_lsb(bit_stream, nbits);
+    return bits;
+}
+
+/**
+ * Get bits from the bit buffer reading them from the least significant bits
+ * moving to the most significant bits. In case there are fewer bits, refill from
+ * buf moving forward.
+ */
+av_always_inline
+static uint64_t jpeg2000_bitbuf_get_bits_lsb_forward(StateVars *bit_stream,
+                                                     uint8_t nbits, const uint8_t *buf,
+                                                     uint32_t length)
+{
+    uint64_t bits;
+    uint64_t mask = (1ull << nbits) - 1;
+
+    if (bit_stream->bits_left <= nbits)
+        jpeg2000_bitbuf_refill_forward(bit_stream, buf, length);
+    bits = bit_stream->bit_buf & mask;
+    jpeg2000_bitbuf_drop_bits_lsb(bit_stream, nbits);
+    return bits;
+}
+
+/**
+ * Look ahead bit buffer without discarding bits.
+ */
+av_always_inline
+static uint64_t jpeg2000_bitbuf_peek_bits_lsb(StateVars *stream, uint8_t nbits)
+{
+    uint64_t mask = (1ull << nbits) - 1;
+    return stream->bit_buf & mask;
+}
+
+static void jpeg2000_init_vlc(StateVars *s, uint32_t Lcup, uint32_t Pcup,
+                              const uint8_t *Dcup)
+{
+    s->bits_left = 0;
+    s->bit_buf   = 0;
+    s->pos       = Lcup - 2 - Pcup;
+    s->last      = Dcup[Lcup - 2];
+    s->tmp       = (s->last) >> 4;
+    s->bits      = ((s->tmp & 7) < 7) ? 4 : 3;
+
+    jpeg2000_bitbuf_refill_backwards(s, Dcup + Pcup);
+    jpeg2000_bitbuf_drop_bits_lsb(s, 4);
+}
+
+/**
+ * Decode prefix codes for VLC segment. See Rec. ITU-T T.814, 7.3.5.
+ */
+av_always_inline
+static int  jpeg2000_decode_ctx_vlc(const Jpeg2000DecoderContext *s,
+                                    StateVars *vlc_stream, const uint16_t *table,
+                                    const uint8_t *Dcup, uint8_t *sig_pat,
+                                    uint8_t *res_off, uint8_t *emb_pat_k,
+                                    uint8_t *emb_pat_1, uint8_t pos,
+                                    uint32_t Pcup, uint16_t context)
+{
+    uint32_t value;
+    uint8_t len;
+    uint64_t index;
+    uint64_t code_word;
+
+    jpeg2000_bitbuf_refill_backwards(vlc_stream, Dcup + Pcup);
+
+    code_word = vlc_stream->bit_buf & 0x7f;
+    index = code_word + (context << 7);
+
+    av_assert0(index < 1024); // The CxtVLC table has 1024 entries.
+
+    value = table[index];
+
+    len = (value & 0x000F) >> 1;
+
+    res_off[pos] = (uint8_t) (value & 1);
+    sig_pat[pos] = (uint8_t) ((value & 0x00F0) >> 4);
+    emb_pat_k[pos] = (uint8_t) ((value & 0x0F00) >> 8);
+    emb_pat_1[pos] = (uint8_t) ((value & 0xF000) >> 12);
+
+    jpeg2000_bitbuf_drop_bits_lsb(vlc_stream, len);
+    return 0;
+}
+
+/**
+ * Decode variable length u-vlc prefix. See decodeUPrefix procedure at Rec.
+ * ITU-T T.814, 7.3.6.
+ */
+av_always_inline
+static uint8_t vlc_decode_u_prefix(StateVars *vlc_stream, const uint8_t *refill_array)
+{
+    static const uint8_t return_value[8] = { 5, 1, 2, 1, 3, 1, 2, 1 };
+    static const uint8_t drop_bits[8]    = { 3, 1, 2, 1, 3, 1, 2, 1 };
+
+    uint8_t bits;
+
+    if (vlc_stream->bits_left < 3)
+        jpeg2000_bitbuf_refill_backwards(vlc_stream, refill_array);
+
+    bits = jpeg2000_bitbuf_peek_bits_lsb(vlc_stream, 3);
+
+    jpeg2000_bitbuf_drop_bits_lsb(vlc_stream, drop_bits[bits]);
+    return return_value[bits];
+}
+
+/**
+ * Decode variable length u-vlc suffix. See decodeUSuffix procedure at Rec.
+ * ITU-T T.814, 7.3.6.
+ */
+av_always_inline
+static uint8_t vlc_decode_u_suffix(StateVars *vlc_stream, uint8_t suffix,
+                                   const uint8_t *refill_array)
+{
+    static const int mask[]      = { 1, 31 };
+    static const int drop_bits[] = { 1, 5  };
+
+    uint8_t bits;
+    int cond = suffix != 3;
+    if (suffix < 3)
+        return 0;
+
+    if (vlc_stream->bits_left < 5)
+        jpeg2000_bitbuf_refill_backwards(vlc_stream, refill_array);
+
+    bits = jpeg2000_bitbuf_peek_bits_lsb(vlc_stream, 5);
+
+    jpeg2000_bitbuf_drop_bits_lsb(vlc_stream, drop_bits[cond]);
+    return bits & mask[cond];
+}
+
+/**
+ * Decode u-vlc extension values. See decodeUExtension procedure at Rec. ITU-T
+ * T.814, 7.3.6.
+ */
+av_always_inline
+static uint8_t vlc_decode_u_extension(StateVars *vlc_stream, uint8_t suffix,
+                                      const uint8_t *refill_array)
+{
+    return jpeg2000_bitbuf_get_bits_lsb(vlc_stream, 4 * (suffix >= 28), refill_array);
+}
+
+/**
+ * Magnitude and Sign decode procedures. See decodeMagSgnValue procedure at Rec.
+ * ITU-T T.814, 7.3.8.
+ */
+av_always_inline
+static int32_t jpeg2000_decode_mag_sgn(StateVars *mag_sgn_stream, int32_t m_n,
+                                       int32_t i_n, const uint8_t *buf, uint32_t length)
+{
+    int32_t val = 0;
+    if (m_n > 0) {
+        val = jpeg2000_bitbuf_get_bits_lsb_forward(mag_sgn_stream,m_n,buf,length);
+        val += (i_n << m_n);
+    }
+    return val;
+}
+
+av_always_inline
+static void recover_mag_sgn(StateVars *mag_sgn, uint8_t pos, uint16_t q, int32_t m_n[2],
+                            int32_t known_1[2], const uint8_t emb_pat_1[2],
+                            int32_t v[2][4], int32_t m[2][4], uint8_t *E,
+                            uint32_t *mu_n, const uint8_t *Dcup, uint32_t Pcup,
+                            uint32_t pLSB)
+{
+    for (int i = 0; i < 4; i++) {
+        int32_t n = 4 * q + i;
+        m_n[pos] = m[pos][i];
+        known_1[pos] = (emb_pat_1[pos] >> i) & 1;
+        v[pos][i] = jpeg2000_decode_mag_sgn(mag_sgn, m_n[pos], known_1[pos], Dcup, Pcup);
+
+        if (m_n[pos] != 0) {
+            E[n] = 32 - ff_clz(v[pos][i] | 1);
+            mu_n[n] = (v[pos][i] >> 1) + 1;
+            mu_n[n] <<= pLSB;
+            mu_n[n] |= ((uint32_t) (v[pos][i] & 1)) << 31; // sign bit.
+        }
+    }
+}
+
+static int jpeg2000_import_bit(StateVars *stream, const uint8_t *array, uint32_t length)
+{
+    int cond = stream->pos <= length;
+    int pos = FFMIN(stream->pos, length);
+    if (stream->bits == 0) {
+        stream->bits = (stream->tmp == 0xFF) ? 7 : 8;
+        stream->pos += cond;
+        stream->tmp = cond ? array[pos] : 0xFF;
+    }
+    stream->bits -= 1;
+    return (stream->tmp >> stream->bits) & 1;
+}
+
+static int jpeg2000_peek_bit(StateVars *stream, const uint8_t *array, uint32_t length)
+{
+    if (stream->bits == 0) {
+        int cond = stream->pos <= length;
+        int pos = FFMIN(stream->pos, length);
+        stream->bits = (stream->tmp == 0xFF) ? 7 : 8;
+        stream->pos += cond;
+        stream->tmp = cond ? array[pos] : 0xFF;
+    }
+    return (stream->tmp >> stream->bits) & 1;
+}
+
+static int jpeg2000_decode_mel_sym(MelDecoderState *mel_state,
+                                   StateVars *mel_stream,
+                                   const uint8_t *Dcup,
+                                   uint32_t Lcup)
+{
+
+    if (mel_state->run == 0 && mel_state->one == 0) {
+        uint8_t eval;
+        uint8_t bit;
+
+        eval = mel_e[mel_state->k];
+        bit = jpeg2000_import_bit(mel_stream, Dcup, Lcup);
+        if (bit == 1) {
+            mel_state->run = 1 << eval;
+            mel_state->k = FFMIN(12, mel_state->k + 1);
+        } else {
+            mel_state->run = 0;
+            while (eval > 0) {
+                bit = jpeg2000_import_bit(mel_stream, Dcup, Lcup);
+                mel_state->run = (2 * (mel_state->run)) + bit;
+                eval -= 1;
+            }
+            mel_state->k = FFMAX(0, mel_state->k - 1);
+            mel_state->one = 1;
+        }
+    }
+    if (mel_state->run > 0) {
+        mel_state->run -= 1;
+        return 0;
+    } else {
+        mel_state->one = 0;
+        return 1;
+    }
+}
+
+/**
+ * Magref decoding procedures.
+ */
+av_always_inline
+static int jpeg2000_import_magref_bit(StateVars *stream, const uint8_t *array,
+                                      uint32_t length)
+{
+    return jpeg2000_bitbuf_get_bits_lsb(stream, 1, array);
+}
+
+/**
+ * Signal EMB decode.
+ */
+static int jpeg2000_decode_sig_emb(const Jpeg2000DecoderContext *s, MelDecoderState *mel_state,
+                                   StateVars *mel_stream, StateVars *vlc_stream,
+                                   const uint16_t *vlc_table, const uint8_t *Dcup,
+                                   uint8_t *sig_pat, uint8_t *res_off, uint8_t *emb_pat_k,
+                                   uint8_t *emb_pat_1, uint8_t pos, uint16_t context,
+                                   uint32_t Lcup, uint32_t Pcup)
+{
+    if (context == 0) {
+        uint8_t sym;
+        sym = jpeg2000_decode_mel_sym(mel_state, mel_stream, Dcup, Lcup);
+        if (sym == 0) {
+            sig_pat[pos] = 0;
+            res_off[pos] = 0;
+            emb_pat_k[pos] = 0;
+            emb_pat_1[pos] = 0;
+            return 0;
+        }
+    }
+    return jpeg2000_decode_ctx_vlc(s, vlc_stream, vlc_table, Dcup, sig_pat,
+                                   res_off, emb_pat_k, emb_pat_1, pos, Pcup,
+                                   context);
+}
+
+av_always_inline
+static int jpeg2000_get_state(int x1, int x2, int width, int shift_by,
+                              const uint8_t *block_states)
+{
+    return (block_states[(x1 + 1) * (width + 2) + (x2 + 1)] >> shift_by) & 1;
+}
+
+av_always_inline
+static void jpeg2000_modify_state(int x1, int x2, int width,
+                                 int value, uint8_t *block_states)
+{
+    block_states[(x1 + 1) * (width + 2) + (x2 + 1)] |= value;
+}
+
+av_always_inline
+static int jpeg2000_decode_ht_cleanup_segment(const Jpeg2000DecoderContext *s,
+                                              Jpeg2000Cblk *cblk, Jpeg2000T1Context *t1,
+                                              MelDecoderState *mel_state,
+                                              StateVars *mel_stream, StateVars *vlc_stream,
+                                              StateVars *mag_sgn_stream, const uint8_t *Dcup,
+                                              uint32_t Lcup, uint32_t Pcup, uint8_t pLSB,
+                                              int width, int height, int32_t *sample_buf,
+                                              uint8_t *block_states)
+{
+    uint16_t q                      = 0;     // Represents current quad position
+    uint16_t q1, q2;
+    uint16_t context1, context2;
+    uint16_t context                = 0;
+
+    uint8_t sig_pat[2]              = { 0 }; // significance pattern
+    uint8_t res_off[2]              = { 0 }; // residual offset
+    uint8_t emb_pat_k[2]            = { 0 }; // exponent Max Bound pattern K
+    uint8_t emb_pat_1[2]            = { 0 }; // exponent Max Bound pattern 1
+    uint8_t gamma[2]                = { 0 };
+
+    uint8_t E_n[2]                  = { 0 };
+    uint8_t E_ne[2]                 = { 0 };
+    uint8_t E_nw[2]                 = { 0 };
+    uint8_t E_nf[2]                 = { 0 };
+
+    uint8_t max_e[2]                = { 0 };
+    uint8_t u_pfx[2]                = { 0 };
+    uint8_t u_sfx[2]                = { 0 };
+    uint8_t u_ext[2]                = { 0 };
+
+    int32_t u[2]                    = { 0 };
+    int32_t U[2]                    = { 0 }; // exponent bound
+    int32_t m_n[2]                  = { 0 };
+    int32_t known_1[2]              = { 0 };
+
+    int32_t m[2][4]                 = { 0 };
+    int32_t v[2][4]                 = { 0 };
+
+    uint8_t kappa[2]                = { 1, 1 };
+
+    int ret                         = 0;
+
+    int sp;
+
+    uint64_t c;
+
+    uint8_t *sigma;
+    uint32_t *mu;
+
+    const uint8_t *vlc_buf = Dcup + Pcup;
+
+    /* convert to raster-scan */
+    const uint16_t is_border_x = width % 2;
+    const uint16_t is_border_y = height % 2;
+
+    const uint16_t quad_width  = ff_jpeg2000_ceildivpow2(width, 1);
+    const uint16_t quad_height = ff_jpeg2000_ceildivpow2(height, 1);
+
+    size_t buf_size = 4 * quad_width * quad_height;
+
+    uint8_t *sigma_n = av_calloc(buf_size, sizeof(uint8_t));
+    uint8_t *E       = av_calloc(buf_size, sizeof(uint8_t));
+    uint32_t *mu_n   = av_calloc(buf_size, sizeof(uint32_t));
+
+    if (!sigma_n || !E || !mu_n) {
+        ret = AVERROR(ENOMEM);
+        goto free;
+    }
+
+    sigma = sigma_n;
+    mu = mu_n;
+
+    while (q < quad_width - 1) {
+        q1 = q;
+        q2 = q1 + 1;
+
+        if ((ret = jpeg2000_decode_sig_emb(s, mel_state, mel_stream, vlc_stream,
+                                           dec_cxt_vlc_table0, Dcup, sig_pat, res_off,
+                                           emb_pat_k, emb_pat_1, J2K_Q1, context, Lcup,
+                                           Pcup)) < 0)
+            goto free;
+
+        for (int i = 0; i < 4; i++)
+            sigma_n[4 * q1 + i] = (sig_pat[J2K_Q1] >> i) & 1;
+
+        /* calculate context */
+        context  = sigma_n[4 * q1];           // f
+        context |= sigma_n[4 * q1 + 1];       // sf
+        context += sigma_n[4 * q1 + 2] << 1;  // w << 1
+        context += sigma_n[4 * q1 + 3] << 2;
+
+        if ((ret = jpeg2000_decode_sig_emb(s, mel_state, mel_stream, vlc_stream,
+                                           dec_cxt_vlc_table0, Dcup, sig_pat, res_off,
+                                           emb_pat_k, emb_pat_1, J2K_Q2, context, Lcup,
+                                           Pcup)) < 0)
+            goto free;
+
+        for (int i = 0; i < 4; i++)
+            sigma_n[4 * q2 + i] = (sig_pat[J2K_Q2] >> i) & 1;
+
+        /* calculate context for the next quad */
+        context  = sigma_n[4 * q2];           // f
+        context |= sigma_n[4 * q2 + 1];       // sf
+        context += sigma_n[4 * q2 + 2] << 1;  // w << 1
+        context += sigma_n[4 * q2 + 3] << 2;  // sw << 2
+
+        u[0] = 0;
+        u[1] = 0;
+
+        jpeg2000_bitbuf_refill_backwards(vlc_stream, vlc_buf);
+
+        if (res_off[J2K_Q1] == 1 && res_off[J2K_Q2] == 1) {
+
+            if (jpeg2000_decode_mel_sym(mel_state, mel_stream, Dcup, Lcup) == 1) {
+
+                u_pfx[J2K_Q1] = vlc_decode_u_prefix(vlc_stream, vlc_buf);
+                u_pfx[J2K_Q2] = vlc_decode_u_prefix(vlc_stream, vlc_buf);
+
+                u_sfx[J2K_Q1] = vlc_decode_u_suffix(vlc_stream, u_pfx[J2K_Q1], vlc_buf);
+                u_sfx[J2K_Q2] = vlc_decode_u_suffix(vlc_stream, u_pfx[J2K_Q2], vlc_buf);
+
+                u_ext[J2K_Q1] = vlc_decode_u_extension(vlc_stream, u_sfx[J2K_Q1], vlc_buf);
+                u_ext[J2K_Q2] = vlc_decode_u_extension(vlc_stream, u_sfx[J2K_Q2], vlc_buf);
+
+                u[J2K_Q1] = 2 + u_pfx[J2K_Q1] + u_sfx[J2K_Q1] + (u_ext[J2K_Q1] * 4);
+                u[J2K_Q2] = 2 + u_pfx[J2K_Q2] + u_sfx[J2K_Q2] + (u_ext[J2K_Q2] * 4);
+
+            } else {
+                u_pfx[J2K_Q1] = vlc_decode_u_prefix(vlc_stream, vlc_buf);
+
+                if (u_pfx[J2K_Q1] > 2) {
+                    u[J2K_Q2] = jpeg2000_bitbuf_get_bits_lsb(vlc_stream, 1, vlc_buf) + 1;
+                    u_sfx[J2K_Q1] = vlc_decode_u_suffix(vlc_stream, u_pfx[J2K_Q1], vlc_buf);
+                    u_ext[J2K_Q1] = vlc_decode_u_extension(vlc_stream, u_sfx[J2K_Q1], vlc_buf);
+                } else {
+                    u_pfx[J2K_Q2] = vlc_decode_u_prefix(vlc_stream, vlc_buf);
+                    u_sfx[J2K_Q1] = vlc_decode_u_suffix(vlc_stream, u_pfx[J2K_Q1], vlc_buf);
+                    u_sfx[J2K_Q2] = vlc_decode_u_suffix(vlc_stream, u_pfx[J2K_Q2], vlc_buf);
+                    u_ext[J2K_Q1] = vlc_decode_u_extension(vlc_stream, u_sfx[J2K_Q1], vlc_buf);
+                    u_ext[J2K_Q2] = vlc_decode_u_extension(vlc_stream, u_sfx[J2K_Q2], vlc_buf);
+                    u[J2K_Q2] = u_pfx[J2K_Q2] + u_sfx[J2K_Q2] + (u_ext[J2K_Q2] * 4);
+                }
+                /* See Rec. ITU-T T.814, 7.3.6(3) */
+                u[J2K_Q1] = u_pfx[J2K_Q1] + u_sfx[J2K_Q1] + (u_ext[J2K_Q1] * 4);
+            }
+
+        } else if (res_off[J2K_Q1] == 1 || res_off[J2K_Q2] == 1) {
+            uint8_t pos = res_off[J2K_Q1] == 1 ? 0 : 1;
+            u_pfx[pos] = vlc_decode_u_prefix(vlc_stream, vlc_buf);
+            u_sfx[pos] = vlc_decode_u_suffix(vlc_stream, u_pfx[pos], vlc_buf);
+            u_ext[pos] = vlc_decode_u_extension(vlc_stream, u_sfx[pos], vlc_buf);
+            u[pos] = u_pfx[pos] + u_sfx[pos] + (u_ext[pos] * 4);
+        }
+        U[J2K_Q1] = kappa[J2K_Q1] + u[J2K_Q1];
+        U[J2K_Q2] = kappa[J2K_Q2] + u[J2K_Q2];
+
+        for (int i = 0; i < 4; i++) {
+            m[J2K_Q1][i] = sigma_n[4 * q1 + i] * U[J2K_Q1] - ((emb_pat_k[J2K_Q1] >> i) & 1);
+            m[J2K_Q2][i] = sigma_n[4 * q2 + i] * U[J2K_Q2] - ((emb_pat_k[J2K_Q2] >> i) & 1);
+        }
+
+        recover_mag_sgn(mag_sgn_stream, J2K_Q1, q1, m_n, known_1, emb_pat_1, v, m,
+                        E, mu_n, Dcup, Pcup, pLSB);
+
+        recover_mag_sgn(mag_sgn_stream, J2K_Q2, q2, m_n, known_1, emb_pat_1, v, m,
+                        E, mu_n, Dcup, Pcup, pLSB);
+
+        q += 2; // Move to the next quad pair
+    }
+
+    if (quad_width % 2 == 1) {
+        q1 = q;
+
+        if ((ret = jpeg2000_decode_sig_emb(s, mel_state, mel_stream, vlc_stream,
+                                           dec_cxt_vlc_table0, Dcup, sig_pat, res_off,
+                                           emb_pat_k, emb_pat_1, J2K_Q1, context, Lcup,
+                                           Pcup)) < 0)
+            goto free;
+
+        for (int i = 0; i < 4; i++)
+            sigma_n[4 * q1 + i] = (sig_pat[J2K_Q1] >> i) & 1;
+
+        u[J2K_Q1] = 0;
+
+        if (res_off[J2K_Q1] == 1) {
+            u_pfx[J2K_Q1] = vlc_decode_u_prefix(vlc_stream, vlc_buf);
+            u_sfx[J2K_Q1] = vlc_decode_u_suffix(vlc_stream, u_pfx[J2K_Q1], vlc_buf);
+            u_ext[J2K_Q1] = vlc_decode_u_extension(vlc_stream, u_sfx[J2K_Q1], vlc_buf);
+            u[J2K_Q1] = u_pfx[J2K_Q1] + u_sfx[J2K_Q1] + (u_ext[J2K_Q1] * 4);
+        }
+
+        U[J2K_Q1] = kappa[J2K_Q1] + u[J2K_Q1];
+
+        for (int i = 0; i < 4; i++)
+            m[J2K_Q1][i] = sigma_n[4 * q1 + i] * U[J2K_Q1] - ((emb_pat_k[J2K_Q1] >> i) & 1);
+
+        recover_mag_sgn(mag_sgn_stream, J2K_Q1, q1, m_n, known_1, emb_pat_1, v, m,
+                        E, mu_n, Dcup, Pcup, pLSB);
+
+        q++; // move to next quad pair
+    }
+
+    /**
+     * Initial line pair end. As an optimization, we can replace modulo
+     * operations with checking if a number is divisible , since that's the only
+     * thing we need. This is paired with is_divisible. Credits to Daniel Lemire
+     * blog post [1].
+     *
+     * [1]
+     * https://lemire.me/blog/2019/02/08/faster-remainders-when-the-divisor-is-a-constant-beating-compilers-and-libdivide/
+     *
+     * It's UB on zero, but the spec doesn't allow a quad being zero, so we
+     * error out early in case that's the case.
+     */
+    c = precompute_c(quad_width);
+
+    for (int row = 1; row < quad_height; row++) {
+        while ((q - (row * quad_width)) < quad_width - 1 && q < (quad_height * quad_width)) {
+            q1 = q;
+            q2 = q + 1;
+            context1  = sigma_n[4 * (q1 - quad_width) + 1];
+            context1 += sigma_n[4 * (q1 - quad_width) + 3] << 2;              // ne
+
+            if (!is_divisible(q1, c)) {
+                context1 |= sigma_n[4 * (q1 - quad_width) - 1];               // nw
+                context1 += (sigma_n[4 * q1 - 1] | sigma_n[4 * q1 - 2]) << 1; // sw | q
+            }
+            if (!is_divisible(q1 + 1, c))
+                context1 |= sigma_n[4 * (q1 - quad_width) + 5] << 2;
+
+            if ((ret = jpeg2000_decode_sig_emb(s, mel_state, mel_stream, vlc_stream,
+                                               dec_cxt_vlc_table1, Dcup, sig_pat, res_off,
+                                               emb_pat_k, emb_pat_1, J2K_Q1, context1, Lcup,
+                                               Pcup))
+                < 0)
+                goto free;
+
+            for (int i = 0; i < 4; i++)
+                sigma_n[4 * q1 + i] = (sig_pat[J2K_Q1] >> i) & 1;
+
+            context2  = sigma_n[4 * (q2 - quad_width) + 1];
+            context2 += sigma_n[4 * (q2 - quad_width) + 3] << 2;
+
+            if (!is_divisible(q2, c)) {
+                context2 |= sigma_n[4 * (q2 - quad_width) - 1];
+                context2 += (sigma_n[4 * q2 - 1] | sigma_n[4 * q2 - 2]) << 1;
+            }
+            if (!is_divisible(q2 + 1, c))
+                context2 |= sigma_n[4 * (q2 - quad_width) + 5] << 2;
+
+            if ((ret = jpeg2000_decode_sig_emb(s, mel_state, mel_stream, vlc_stream,
+                                               dec_cxt_vlc_table1, Dcup, sig_pat, res_off,
+                                               emb_pat_k, emb_pat_1, J2K_Q2, context2, Lcup,
+                                               Pcup))
+                < 0)
+                goto free;
+
+            for (int i = 0; i < 4; i++)
+                sigma_n[4 * q2 + i] = (sig_pat[J2K_Q2] >> i) & 1;
+
+            u[J2K_Q1] = 0;
+            u[J2K_Q2] = 0;
+
+            jpeg2000_bitbuf_refill_backwards(vlc_stream, vlc_buf);
+
+            if (res_off[J2K_Q1] == 1 && res_off[J2K_Q2] == 1) {
+                u_pfx[J2K_Q1] = vlc_decode_u_prefix(vlc_stream, vlc_buf);
+                u_pfx[J2K_Q2] = vlc_decode_u_prefix(vlc_stream, vlc_buf);
+
+                u_sfx[J2K_Q1] = vlc_decode_u_suffix(vlc_stream, u_pfx[J2K_Q1], vlc_buf);
+                u_sfx[J2K_Q2] = vlc_decode_u_suffix(vlc_stream, u_pfx[J2K_Q2], vlc_buf);
+
+                u_ext[J2K_Q1] = vlc_decode_u_extension(vlc_stream, u_sfx[J2K_Q1], vlc_buf);
+                u_ext[J2K_Q2] = vlc_decode_u_extension(vlc_stream, u_sfx[J2K_Q2], vlc_buf);
+
+                u[J2K_Q1] = u_pfx[J2K_Q1] + u_sfx[J2K_Q1] + (u_ext[J2K_Q1] << 2);
+                u[J2K_Q2] = u_pfx[J2K_Q2] + u_sfx[J2K_Q2] + (u_ext[J2K_Q2] << 2);
+
+            } else if (res_off[J2K_Q1] == 1 || res_off[J2K_Q2] == 1) {
+                uint8_t pos = res_off[J2K_Q1] == 1 ? 0 : 1;
+
+                u_pfx[pos] = vlc_decode_u_prefix(vlc_stream, vlc_buf);
+                u_sfx[pos] = vlc_decode_u_suffix(vlc_stream, u_pfx[pos], vlc_buf);
+                u_ext[pos] = vlc_decode_u_extension(vlc_stream, u_sfx[pos], vlc_buf);
+
+                u[pos] = u_pfx[pos] + u_sfx[pos] + (u_ext[pos] << 2);
+            }
+            sp = sig_pat[J2K_Q1];
+
+            gamma[J2K_Q1] = 1;
+
+            if (sp == 0 || sp == 1 || sp == 2 || sp == 4 || sp == 8)
+                gamma[J2K_Q1] = 0;
+
+            sp = sig_pat[J2K_Q2];
+
+            gamma[J2K_Q2] = 1;
+
+            if (sp == 0 || sp == 1 || sp == 2 || sp == 4 || sp == 8)
+                gamma[J2K_Q2] = 0;
+
+            E_n[J2K_Q1] = E[4 * (q1 - quad_width) + 1];
+            E_n[J2K_Q2] = E[4 * (q2 - quad_width) + 1];
+
+            E_ne[J2K_Q1] = E[4 * (q1 - quad_width) + 3];
+            E_ne[J2K_Q2] = E[4 * (q2 - quad_width) + 3];
+
+            E_nw[J2K_Q1] = (!is_divisible(q1, c)) * E[FFMAX((4 * (q1 - quad_width) - 1), 0)];
+            E_nw[J2K_Q2] = (!is_divisible(q2, c)) * E[FFMAX((4 * (q2 - quad_width) - 1), 0)];
+
+            E_nf[J2K_Q1] = (!is_divisible(q1 + 1, c)) * E[4 * (q1 - quad_width) + 5];
+            E_nf[J2K_Q2] = (!is_divisible(q2 + 1, c)) * E[4 * (q2 - quad_width) + 5];
+
+            max_e[J2K_Q1] = FFMAX(E_nw[J2K_Q1], FFMAX3(E_n[J2K_Q1], E_ne[J2K_Q1], E_nf[J2K_Q1]));
+            max_e[J2K_Q2] = FFMAX(E_nw[J2K_Q2], FFMAX3(E_n[J2K_Q2], E_ne[J2K_Q2], E_nf[J2K_Q2]));
+
+            kappa[J2K_Q1] = FFMAX(1, gamma[J2K_Q1] * (max_e[J2K_Q1] - 1));
+            kappa[J2K_Q2] = FFMAX(1, gamma[J2K_Q2] * (max_e[J2K_Q2] - 1));
+
+            U[J2K_Q1] = kappa[J2K_Q1] + u[J2K_Q1];
+            U[J2K_Q2] = kappa[J2K_Q2] + u[J2K_Q2];
+
+            for (int i = 0; i < 4; i++) {
+                m[J2K_Q1][i] = sigma_n[4 * q1 + i] * U[J2K_Q1] - ((emb_pat_k[J2K_Q1] >> i) & 1);
+                m[J2K_Q2][i] = sigma_n[4 * q2 + i] * U[J2K_Q2] - ((emb_pat_k[J2K_Q2] >> i) & 1);
+            }
+            recover_mag_sgn(mag_sgn_stream, J2K_Q1, q1, m_n, known_1, emb_pat_1, v, m,
+                            E, mu_n, Dcup, Pcup, pLSB);
+
+            recover_mag_sgn(mag_sgn_stream, J2K_Q2, q2, m_n, known_1, emb_pat_1, v, m,
+                            E, mu_n, Dcup, Pcup, pLSB);
+
+            q += 2; // Move to the next quad pair
+        }
+
+        if (quad_width % 2 == 1) {
+            q1 = q;
+
+            /* calculate context for current quad */
+            context1  = sigma_n[4 * (q1 - quad_width) + 1];
+            context1 += (sigma_n[4 * (q1 - quad_width) + 3] << 2);
+
+            if (!is_divisible(q1, c)) {
+                context1 |= sigma_n[4 * (q1 - quad_width) - 1];
+                context1 += (sigma_n[4 * q1 - 1] | sigma_n[4 * q1 - 2]) << 1;
+            }
+            if (!is_divisible(q1 + 1, c))
+                context1 |= sigma_n[4 * (q1 - quad_width) + 5] << 2;
+
+            if ((ret = jpeg2000_decode_sig_emb(s, mel_state, mel_stream, vlc_stream,
+                                               dec_cxt_vlc_table1, Dcup, sig_pat, res_off,
+                                               emb_pat_k, emb_pat_1, J2K_Q1, context1, Lcup,
+                                               Pcup)) < 0)
+                goto free;
+
+            for (int i = 0; i < 4; i++)
+                sigma_n[4 * q1 + i] = (sig_pat[J2K_Q1] >> i) & 1;
+
+            u[J2K_Q1] = 0;
+
+            /* Recover mag_sgn value */
+            if (res_off[J2K_Q1] == 1) {
+                u_pfx[J2K_Q1] = vlc_decode_u_prefix(vlc_stream, vlc_buf);
+                u_sfx[J2K_Q1] = vlc_decode_u_suffix(vlc_stream, u_pfx[J2K_Q1], vlc_buf);
+                u_ext[J2K_Q1] = vlc_decode_u_extension(vlc_stream, u_sfx[J2K_Q1], vlc_buf);
+
+                u[J2K_Q1] = u_pfx[J2K_Q1] + u_sfx[J2K_Q1] + (u_ext[J2K_Q1] << 2);
+            }
+
+            sp = sig_pat[J2K_Q1];
+
+            gamma[J2K_Q1] = 1;
+
+            if (sp == 0 || sp == 1 || sp == 2 || sp == 4 || sp == 8)
+                gamma[J2K_Q1] = 0;
+
+            E_n[J2K_Q1] = E[4 * (q1 - quad_width) + 1];
+
+            E_ne[J2K_Q1] = E[4 * (q1 - quad_width) + 3];
+
+            E_nw[J2K_Q1] = (!is_divisible(q1, c)) * E[FFMAX((4 * (q1 - quad_width) - 1), 0)];
+
+            E_nf[J2K_Q1] = (!is_divisible(q1 + 1, c)) * E[4 * (q1 - quad_width) + 5];
+
+            max_e[J2K_Q1] = FFMAX(E_nw[J2K_Q1], FFMAX3(E_n[J2K_Q1], E_ne[J2K_Q1], E_nf[J2K_Q1]));
+
+            kappa[J2K_Q1] = FFMAX(1, gamma[J2K_Q1] * (max_e[J2K_Q1] - 1));
+
+            U[J2K_Q1] = kappa[J2K_Q1] + u[J2K_Q1];
+
+            for (int i = 0; i < 4; i++)
+                m[J2K_Q1][i] = sigma_n[4 * q1 + i] * U[J2K_Q1] - ((emb_pat_k[J2K_Q1] >> i) & 1);
+
+            recover_mag_sgn(mag_sgn_stream, J2K_Q1, q1, m_n, known_1, emb_pat_1, v, m,
+                            E, mu_n, Dcup, Pcup, pLSB);
+            q += 1;
+        }
+    }
+
+    // convert to raster-scan
+    for (int y = 0; y < quad_height; y++) {
+        for (int x = 0; x < quad_width; x++) {
+            int j1, j2;
+            int x1, x2 , x3;
+
+            j1 = 2 * y;
+            j2 = 2 * x;
+
+            sample_buf[j2 + (j1 * width)] = (int32_t)*mu;
+            jpeg2000_modify_state(j1, j2, width, *sigma, block_states);
+            sigma += 1;
+            mu += 1;
+
+            x1 = y != quad_height - 1 || is_border_y == 0;
+            sample_buf[j2 + ((j1 + 1) * width)] = ((int32_t)*mu) * x1;
+            jpeg2000_modify_state(j1 + 1, j2, width, (*sigma) * x1, block_states);
+            sigma += 1;
+            mu += 1;
+
+            x2 = x != quad_width - 1 || is_border_x == 0;
+            sample_buf[(j2 + 1) + (j1 * width)] = ((int32_t)*mu) * x2;
+            jpeg2000_modify_state(j1, j2 + 1, width, (*sigma) * x2, block_states);
+            sigma += 1;
+            mu += 1;
+
+            x3 = x1 | x2;
+            sample_buf[(j2 + 1) + (j1 + 1) * width] = ((int32_t)*mu) * x3;
+            jpeg2000_modify_state(j1 + 1, j2 + 1, width, (*sigma) * x3, block_states);
+            sigma += 1;
+            mu += 1;
+        }
+    }
+    ret = 1;
+free:
+    av_freep(&sigma_n);
+    av_freep(&E);
+    av_freep(&mu_n);
+    return ret;
+}
+
+static void jpeg2000_calc_mbr(uint8_t *mbr, const uint16_t i, const uint16_t j,
+                              const uint32_t mbr_info, uint8_t causal_cond,
+                              uint8_t *block_states, int width)
+{
+    int local_mbr = 0;
+
+    local_mbr |= jpeg2000_get_state(i - 1, j - 1, width, HT_SHIFT_SIGMA, block_states);
+    local_mbr |= jpeg2000_get_state(i - 1, j + 0, width, HT_SHIFT_SIGMA, block_states);
+    local_mbr |= jpeg2000_get_state(i - 1, j + 1, width, HT_SHIFT_SIGMA, block_states);
+
+    local_mbr |= jpeg2000_get_state(i + 0, j - 1, width, HT_SHIFT_SIGMA, block_states);
+    local_mbr |= jpeg2000_get_state(i + 0, j + 1, width, HT_SHIFT_SIGMA, block_states);
+
+    local_mbr |= jpeg2000_get_state(i + 1, j - 1, width, HT_SHIFT_SIGMA, block_states) * causal_cond;
+    local_mbr |= jpeg2000_get_state(i + 1, j + 0, width, HT_SHIFT_SIGMA, block_states) * causal_cond;
+    local_mbr |= jpeg2000_get_state(i + 1, j + 1, width, HT_SHIFT_SIGMA, block_states) * causal_cond;
+
+    local_mbr |= jpeg2000_get_state(i - 1, j - 1, width, HT_SHIFT_REF,   block_states) *
+                 jpeg2000_get_state(i - 1, j - 1, width, HT_SHIFT_SCAN,  block_states);
+    local_mbr |= jpeg2000_get_state(i - 1, j + 0, width, HT_SHIFT_REF,   block_states) *
+                 jpeg2000_get_state(i - 1, j - 1, width, HT_SHIFT_SCAN,  block_states);
+    local_mbr |= jpeg2000_get_state(i - 1, j + 1, width, HT_SHIFT_REF,   block_states) *
+                 jpeg2000_get_state(i - 1, j + 1, width, HT_SHIFT_SCAN,  block_states);
+
+    local_mbr |= jpeg2000_get_state(i + 0, j - 1, width, HT_SHIFT_REF,   block_states) *
+                 jpeg2000_get_state(i + 0, j - 1, width, HT_SHIFT_SCAN,  block_states);
+    local_mbr |= jpeg2000_get_state(i + 0, j + 1, width, HT_SHIFT_REF,   block_states) *
+                 jpeg2000_get_state(i + 0, j + 1, width, HT_SHIFT_SCAN,  block_states);
+
+    local_mbr |= jpeg2000_get_state(i + 1, j - 1, width, HT_SHIFT_REF,  block_states) *
+                 jpeg2000_get_state(i + 1, j - 1, width, HT_SHIFT_SCAN, block_states) * causal_cond;
+    local_mbr |= jpeg2000_get_state(i + 1, j + 0, width, HT_SHIFT_REF,  block_states) *
+                 jpeg2000_get_state(i + 1, j + 0, width, HT_SHIFT_SCAN, block_states) * causal_cond;
+    local_mbr |= jpeg2000_get_state(i + 1, j + 1, width, HT_SHIFT_REF,  block_states) *
+                 jpeg2000_get_state(i + 1, j + 1, width, HT_SHIFT_SCAN, block_states) * causal_cond;
+
+    *mbr |= local_mbr;
+}
+
+static void jpeg2000_process_stripes_block(StateVars *sig_prop, int i_s, int j_s,
+                                           int width, int height, int stride, int pLSB,
+                                           int32_t *sample_buf, uint8_t *block_states,
+                                           uint8_t *magref_segment, uint32_t magref_length)
+{
+    for (int j = j_s; j < j_s + width; j++) {
+        uint32_t  mbr_info = 0;
+        for (int i = i_s; i < i_s + height; i++) {
+            int modify_state, cond;
+            uint8_t bit;
+            uint8_t causal_cond = i != (i_s + height - 1);
+            int32_t *sp = &sample_buf[j + (i * (stride - 2))];
+            uint8_t mbr = 0;
+
+            if (jpeg2000_get_state(i, j, stride - 2, HT_SHIFT_SIGMA, block_states) == 0)
+                jpeg2000_calc_mbr(&mbr, i, j, mbr_info & 0x1EF, causal_cond, block_states, stride - 2);
+            mbr_info >>= 3;
+            cond = mbr != 0;
+            bit = jpeg2000_peek_bit(sig_prop, magref_segment, magref_length);
+            *sp |= (bit * cond) << pLSB;
+            sig_prop->bits -= cond;
+            modify_state = (((1 << HT_SHIFT_REF_IND) | (1 << HT_SHIFT_REF)) * cond) | 1 << HT_SHIFT_SCAN;
+            jpeg2000_modify_state(i, j, stride - 2, modify_state, block_states);
+        }
+    }
+}
+
+/**
+ * See procedure decodeSigPropMag at Rec. ITU-T T.814, 7.4.
+*/
+av_noinline
+static void jpeg2000_decode_sigprop_segment(Jpeg2000Cblk *cblk, uint16_t width,
+                                            uint16_t height, uint8_t *magref_segment,
+                                            uint32_t magref_length, uint8_t pLSB,
+                                            int32_t *sample_buf, uint8_t *block_states)
+{
+    StateVars sp_dec;
+
+    const uint16_t num_v_stripe = height / 4;
+    const uint16_t num_h_stripe = width / 4;
+    int b_width                 = 4;
+    int b_height                = 4;
+    int stride                  = width + 2;
+
+    int last_width;
+    uint16_t i = 0, j = 0;
+
+    jpeg2000_init_zero(&sp_dec);
+
+    for (int n1 = 0; n1 < num_v_stripe; n1++) {
+        j = 0;
+        for (int n2 = 0; n2 < num_h_stripe; n2++) {
+            jpeg2000_process_stripes_block(&sp_dec, i, j, b_width, b_height, stride,
+                                           pLSB, sample_buf, block_states, magref_segment,
+                                           magref_length);
+            j += 4;
+        }
+        last_width = width % 4;
+        if (last_width)
+            jpeg2000_process_stripes_block(&sp_dec, i, j, last_width, b_height, stride,
+                                           pLSB, sample_buf, block_states, magref_segment,
+                                           magref_length);
+        i += 4;
+    }
+
+    /* Decode remaining height stripes */
+    b_height = height % 4;
+    j = 0;
+    for (int n2 = 0; n2 < num_h_stripe; n2++) {
+        jpeg2000_process_stripes_block(&sp_dec, i, j, b_width, b_height, stride,
+                                       pLSB, sample_buf, block_states, magref_segment,
+                                       magref_length);
+        j += 4;
+    }
+    last_width = width % 4;
+    if (last_width)
+        jpeg2000_process_stripes_block(&sp_dec, i, j, last_width, b_height, stride,
+                                       pLSB, sample_buf, block_states, magref_segment,
+                                       magref_length);
+}
+
+/**
+ * See procedure decodeSigPropMag at Rec. ITU-T T.814, 7.5.
+*/
+static int
+jpeg2000_decode_magref_segment(Jpeg2000Cblk *cblk, uint16_t width, uint16_t block_height, uint8_t *magref_segment,
+                       uint32_t magref_length, uint8_t pLSB, int32_t *sample_buf, uint8_t *block_states)
+{
+
+    StateVars mag_ref           = { 0 };
+    const uint16_t num_v_stripe = block_height / 4;
+    uint16_t height             = 4;
+    uint16_t i_start            = 0;
+    int32_t *sp;
+
+    jpeg2000_init_mag_ref(&mag_ref, magref_length);
+
+    for (int n1 = 0; n1 < num_v_stripe; n1++) {
+        for (int j = 0; j < width; j++) {
+            for (int i = i_start; i < i_start + height; i++) {
+                /**
+                 *  We move column wise, going from one quad to another. See
+                 *  Rec. ITU-T T.814, Figure 7.
+                 */
+                sp = &sample_buf[j + i * width];
+                if (jpeg2000_get_state(i, j, width, HT_SHIFT_SIGMA, block_states) != 0) {
+                    jpeg2000_modify_state(i, j, width, 1 << HT_SHIFT_REF_IND, block_states);
+                    *sp |= jpeg2000_import_magref_bit(&mag_ref, magref_segment, magref_length) << pLSB;
+                }
+            }
+        }
+        i_start += 4;
+    }
+    height = block_height % 4;
+    for (int j = 0; j < width; j++) {
+        for (int i = i_start; i < i_start + height; i++) {
+            sp = &sample_buf[j + i * width];
+            if (jpeg2000_get_state(i, j, width, HT_SHIFT_SIGMA, block_states) != 0) {
+                jpeg2000_modify_state(i, j, width, 1 << HT_SHIFT_REF_IND, block_states);
+                *sp |= jpeg2000_import_magref_bit(&mag_ref, magref_segment, magref_length) << pLSB;
+            }
+        }
+    }
+    return 1;
+}
+
+
+int
+ff_jpeg2000_decode_htj2k(const Jpeg2000DecoderContext *s, Jpeg2000CodingStyle *codsty, Jpeg2000T1Context *t1, Jpeg2000Cblk *cblk,
+                         int width, int height, int magp, uint8_t roi_shift)
+{
+    uint8_t p0 = 0;             // Number of placeholder passes
+    uint32_t Lcup;              // Length of HT cleanup segment
+    uint32_t Lref;              // Length of Refinement segment
+    uint32_t Scup;              // HT cleanup segment suffix length
+    uint32_t Pcup;              // HT cleanup segment prefix length
+
+    uint8_t S_blk;              // Number of skipped magnitude bitplanes
+    uint8_t pLSB;
+
+    uint8_t *Dcup;              // Byte of an HT cleanup segment
+    uint8_t *Dref;              // Byte of an HT refinement segment
+
+    int z_blk;                  // Number of ht coding pass
+
+    uint8_t empty_passes;
+
+    StateVars mag_sgn;          // Magnitude and Sign
+    StateVars mel;              // Adaptive run-length coding
+    StateVars vlc;              // Variable Length coding
+    StateVars sig_prop;         // Significance propagation
+
+    MelDecoderState mel_state;
+
+    int ret;
+
+    /* Temporary buffers */
+    int32_t *sample_buf;
+    uint8_t *block_states;
+
+    int32_t n, val;             // Post-processing
+
+    int32_t M_b = magp;
+
+    /* codeblock size as constrained by Rec. ITU-T T.800, Table A.18 */
+    av_assert0(width <= 1024U && height <= 1024U);
+    av_assert0(width * height <= 4096);
+    av_assert0(width * height > 0);
+
+    memset(t1->data, 0, t1->stride * height * sizeof(*t1->data));
+    memset(t1->flags, 0, t1->stride * (height + 2) * sizeof(*t1->flags));
+
+    if (cblk->npasses == 0)
+        return 0;
+
+    if (cblk->npasses > 3)
+        p0 = 0;
+    else if (cblk->length == 0)
+        p0 = 1;
+
+    empty_passes = p0 * 3;
+    z_blk = cblk->npasses - empty_passes;
+
+    if (z_blk <= 0)
+        return 0; // No passes within this set, continue
+
+    Lcup = cblk->pass_lengths[0];
+    Lref = cblk->pass_lengths[1];
+
+    if (Lcup < 2) {
+        av_log(s->avctx, AV_LOG_ERROR,
+               "Cleanup pass length must be at least 2 bytes in length\n");
+        return AVERROR_INVALIDDATA;
+    }
+    Dcup = cblk->data;
+    Dref  = cblk->data + Lcup; // Dref comes after the refinement segment
+    S_blk = p0 + cblk->zbp;
+    pLSB  = 30 - S_blk;
+
+    Scup = (Dcup[Lcup - 1] << 4) + (Dcup[Lcup - 2] & 0x0F);
+
+    if (Scup < 2 || Scup > Lcup || Scup > 4079) {
+        av_log(s->avctx, AV_LOG_ERROR, "Cleanup pass suffix length is invalid %d\n",
+               Scup);
+        ret = AVERROR_INVALIDDATA;
+        goto free;
+    }
+    Pcup = Lcup - Scup;
+
+    /* modDcup shall be done before the creation of vlc instance. */
+    Dcup[Lcup - 1] = 0xFF;
+    Dcup[Lcup - 2] |= 0x0F;
+
+    /* Magnitude and refinement */
+    jpeg2000_init_zero(&mag_sgn);
+    jpeg2000_bitbuf_refill_forward(&mag_sgn, Dcup, Pcup);
+
+    /* Significance propagation */
+    jpeg2000_init_zero(&sig_prop);
+
+    /* Adaptive run length */
+    jpeg2000_init_mel(&mel, Pcup);
+
+    /* Variable Length coding */
+    jpeg2000_init_vlc(&vlc, Lcup, Pcup, Dcup);
+
+    jpeg2000_init_mel_decoder(&mel_state);
+
+    sample_buf = av_calloc((width + 4) * (height + 4), sizeof(int32_t));
+    block_states = av_calloc((width + 4) * (height + 4), sizeof(uint8_t));
+
+    if (!sample_buf || !block_states) {
+        ret = AVERROR(ENOMEM);
+        goto free;
+    }
+    if ((ret = jpeg2000_decode_ht_cleanup_segment(s, cblk, t1, &mel_state, &mel, &vlc,
+                                          &mag_sgn, Dcup, Lcup, Pcup, pLSB, width,
+                                          height, sample_buf, block_states)) < 0)
+        goto free;
+
+    if (cblk->npasses > 1)
+        jpeg2000_decode_sigprop_segment(cblk, width, height, Dref, Lref,
+                                pLSB - 1, sample_buf, block_states);
+
+    if (cblk->npasses > 2)
+        if ((ret = jpeg2000_decode_magref_segment(cblk, width, height, Dref, Lref,
+                                          pLSB - 1, sample_buf, block_states)) < 0)
+            goto free;
+
+    pLSB = 31 - M_b;
+
+    /* Reconstruct the sample values */
+    for (int y = 0; y < height; y++) {
+        for (int x = 0; x < width; x++) {
+            n = x + (y * t1->stride);
+            val = sample_buf[x + (y * width)];
+            /* Convert sign-magnitude to two's complement. */
+            val = val >> 31 ? 0x80000000 - val : val;
+            val >>= (pLSB - 1);
+            t1->data[n] = val;
+        }
+    }
+free:
+    av_freep(&sample_buf);
+    av_freep(&block_states);
+    return ret;
+}
+
+/**
+ * CtxVLC tables (see Rec. ITU-T T.800, Annex C) as found at
+ * https://github.com/osamu620/OpenHTJ2K (author: Osamu Watanabe)
+ */
+static const uint16_t dec_cxt_vlc_table1[1024] = {
+        0x0016, 0x006A, 0x0046, 0x00DD, 0x0086, 0x888B, 0x0026, 0x444D, 0x0016, 0x00AA, 0x0046, 0x88AD, 0x0086,
+        0x003A, 0x0026, 0x00DE, 0x0016, 0x00CA, 0x0046, 0x009D, 0x0086, 0x005A, 0x0026, 0x222D, 0x0016, 0x009A,
+        0x0046, 0x007D, 0x0086, 0x01FD, 0x0026, 0x007E, 0x0016, 0x006A, 0x0046, 0x88CD, 0x0086, 0x888B, 0x0026,
+        0x111D, 0x0016, 0x00AA, 0x0046, 0x005D, 0x0086, 0x003A, 0x0026, 0x00EE, 0x0016, 0x00CA, 0x0046, 0x00BD,
+        0x0086, 0x005A, 0x0026, 0x11FF, 0x0016, 0x009A, 0x0046, 0x003D, 0x0086, 0x04ED, 0x0026, 0x2AAF, 0x0016,
+        0x006A, 0x0046, 0x00DD, 0x0086, 0x888B, 0x0026, 0x444D, 0x0016, 0x00AA, 0x0046, 0x88AD, 0x0086, 0x003A,
+        0x0026, 0x44EF, 0x0016, 0x00CA, 0x0046, 0x009D, 0x0086, 0x005A, 0x0026, 0x222D, 0x0016, 0x009A, 0x0046,
+        0x007D, 0x0086, 0x01FD, 0x0026, 0x00BE, 0x0016, 0x006A, 0x0046, 0x88CD, 0x0086, 0x888B, 0x0026, 0x111D,
+        0x0016, 0x00AA, 0x0046, 0x005D, 0x0086, 0x003A, 0x0026, 0x4CCF, 0x0016, 0x00CA, 0x0046, 0x00BD, 0x0086,
+        0x005A, 0x0026, 0x00FE, 0x0016, 0x009A, 0x0046, 0x003D, 0x0086, 0x04ED, 0x0026, 0x006F, 0x0002, 0x0088,
+        0x0002, 0x005C, 0x0002, 0x0018, 0x0002, 0x00DE, 0x0002, 0x0028, 0x0002, 0x009C, 0x0002, 0x004A, 0x0002,
+        0x007E, 0x0002, 0x0088, 0x0002, 0x00CC, 0x0002, 0x0018, 0x0002, 0x888F, 0x0002, 0x0028, 0x0002, 0x00FE,
+        0x0002, 0x003A, 0x0002, 0x222F, 0x0002, 0x0088, 0x0002, 0x04FD, 0x0002, 0x0018, 0x0002, 0x00BE, 0x0002,
+        0x0028, 0x0002, 0x00BF, 0x0002, 0x004A, 0x0002, 0x006E, 0x0002, 0x0088, 0x0002, 0x00AC, 0x0002, 0x0018,
+        0x0002, 0x444F, 0x0002, 0x0028, 0x0002, 0x00EE, 0x0002, 0x003A, 0x0002, 0x113F, 0x0002, 0x0088, 0x0002,
+        0x005C, 0x0002, 0x0018, 0x0002, 0x00CF, 0x0002, 0x0028, 0x0002, 0x009C, 0x0002, 0x004A, 0x0002, 0x006F,
+        0x0002, 0x0088, 0x0002, 0x00CC, 0x0002, 0x0018, 0x0002, 0x009F, 0x0002, 0x0028, 0x0002, 0x00EF, 0x0002,
+        0x003A, 0x0002, 0x233F, 0x0002, 0x0088, 0x0002, 0x04FD, 0x0002, 0x0018, 0x0002, 0x00AF, 0x0002, 0x0028,
+        0x0002, 0x44FF, 0x0002, 0x004A, 0x0002, 0x005F, 0x0002, 0x0088, 0x0002, 0x00AC, 0x0002, 0x0018, 0x0002,
+        0x007F, 0x0002, 0x0028, 0x0002, 0x00DF, 0x0002, 0x003A, 0x0002, 0x111F, 0x0002, 0x0028, 0x0002, 0x005C,
+        0x0002, 0x008A, 0x0002, 0x00BF, 0x0002, 0x0018, 0x0002, 0x00FE, 0x0002, 0x00CC, 0x0002, 0x007E, 0x0002,
+        0x0028, 0x0002, 0x8FFF, 0x0002, 0x004A, 0x0002, 0x007F, 0x0002, 0x0018, 0x0002, 0x00DF, 0x0002, 0x00AC,
+        0x0002, 0x133F, 0x0002, 0x0028, 0x0002, 0x222D, 0x0002, 0x008A, 0x0002, 0x00BE, 0x0002, 0x0018, 0x0002,
+        0x44EF, 0x0002, 0x2AAD, 0x0002, 0x006E, 0x0002, 0x0028, 0x0002, 0x15FF, 0x0002, 0x004A, 0x0002, 0x009E,
+        0x0002, 0x0018, 0x0002, 0x00CF, 0x0002, 0x003C, 0x0002, 0x223F, 0x0002, 0x0028, 0x0002, 0x005C, 0x0002,
+        0x008A, 0x0002, 0x2BBF, 0x0002, 0x0018, 0x0002, 0x04EF, 0x0002, 0x00CC, 0x0002, 0x006F, 0x0002, 0x0028,
+        0x0002, 0x27FF, 0x0002, 0x004A, 0x0002, 0x009F, 0x0002, 0x0018, 0x0002, 0x00DE, 0x0002, 0x00AC, 0x0002,
+        0x444F, 0x0002, 0x0028, 0x0002, 0x222D, 0x0002, 0x008A, 0x0002, 0x8AAF, 0x0002, 0x0018, 0x0002, 0x00EE,
+        0x0002, 0x2AAD, 0x0002, 0x005F, 0x0002, 0x0028, 0x0002, 0x44FF, 0x0002, 0x004A, 0x0002, 0x888F, 0x0002,
+        0x0018, 0x0002, 0xAAAF, 0x0002, 0x003C, 0x0002, 0x111F, 0x0004, 0x8FFD, 0x0028, 0x005C, 0x0004, 0x00BC,
+        0x008A, 0x66FF, 0x0004, 0x00CD, 0x0018, 0x111D, 0x0004, 0x009C, 0x003A, 0x8AAF, 0x0004, 0x00FC, 0x0028,
+        0x133D, 0x0004, 0x00AC, 0x004A, 0x3BBF, 0x0004, 0x2BBD, 0x0018, 0x5FFF, 0x0004, 0x006C, 0x157D, 0x455F,
+        0x0004, 0x2FFD, 0x0028, 0x222D, 0x0004, 0x22AD, 0x008A, 0x44EF, 0x0004, 0x00CC, 0x0018, 0x4FFF, 0x0004,
+        0x007C, 0x003A, 0x447F, 0x0004, 0x04DD, 0x0028, 0x233D, 0x0004, 0x009D, 0x004A, 0x00DE, 0x0004, 0x88BD,
+        0x0018, 0xAFFF, 0x0004, 0x115D, 0x1FFD, 0x444F, 0x0004, 0x8FFD, 0x0028, 0x005C, 0x0004, 0x00BC, 0x008A,
+        0x8CEF, 0x0004, 0x00CD, 0x0018, 0x111D, 0x0004, 0x009C, 0x003A, 0x888F, 0x0004, 0x00FC, 0x0028, 0x133D,
+        0x0004, 0x00AC, 0x004A, 0x44DF, 0x0004, 0x2BBD, 0x0018, 0x8AFF, 0x0004, 0x006C, 0x157D, 0x006F, 0x0004,
+        0x2FFD, 0x0028, 0x222D, 0x0004, 0x22AD, 0x008A, 0x00EE, 0x0004, 0x00CC, 0x0018, 0x2EEF, 0x0004, 0x007C,
+        0x003A, 0x277F, 0x0004, 0x04DD, 0x0028, 0x233D, 0x0004, 0x009D, 0x004A, 0x1BBF, 0x0004, 0x88BD, 0x0018,
+        0x37FF, 0x0004, 0x115D, 0x1FFD, 0x333F, 0x0002, 0x0088, 0x0002, 0x02ED, 0x0002, 0x00CA, 0x0002, 0x4CCF,
+        0x0002, 0x0048, 0x0002, 0x23FF, 0x0002, 0x001A, 0x0002, 0x888F, 0x0002, 0x0088, 0x0002, 0x006C, 0x0002,
+        0x002A, 0x0002, 0x00AF, 0x0002, 0x0048, 0x0002, 0x22EF, 0x0002, 0x00AC, 0x0002, 0x005F, 0x0002, 0x0088,
+        0x0002, 0x444D, 0x0002, 0x00CA, 0x0002, 0xCCCF, 0x0002, 0x0048, 0x0002, 0x00FE, 0x0002, 0x001A, 0x0002,
+        0x006F, 0x0002, 0x0088, 0x0002, 0x005C, 0x0002, 0x002A, 0x0002, 0x009F, 0x0002, 0x0048, 0x0002, 0x00DF,
+        0x0002, 0x03FD, 0x0002, 0x222F, 0x0002, 0x0088, 0x0002, 0x02ED, 0x0002, 0x00CA, 0x0002, 0x8CCF, 0x0002,
+        0x0048, 0x0002, 0x11FF, 0x0002, 0x001A, 0x0002, 0x007E, 0x0002, 0x0088, 0x0002, 0x006C, 0x0002, 0x002A,
+        0x0002, 0x007F, 0x0002, 0x0048, 0x0002, 0x00EE, 0x0002, 0x00AC, 0x0002, 0x003E, 0x0002, 0x0088, 0x0002,
+        0x444D, 0x0002, 0x00CA, 0x0002, 0x00BE, 0x0002, 0x0048, 0x0002, 0x00BF, 0x0002, 0x001A, 0x0002, 0x003F,
+        0x0002, 0x0088, 0x0002, 0x005C, 0x0002, 0x002A, 0x0002, 0x009E, 0x0002, 0x0048, 0x0002, 0x00DE, 0x0002,
+        0x03FD, 0x0002, 0x111F, 0x0004, 0x8AED, 0x0048, 0x888D, 0x0004, 0x00DC, 0x00CA, 0x3FFF, 0x0004, 0xCFFD,
+        0x002A, 0x003D, 0x0004, 0x00BC, 0x005A, 0x8DDF, 0x0004, 0x8FFD, 0x0048, 0x006C, 0x0004, 0x027D, 0x008A,
+        0x99FF, 0x0004, 0x00EC, 0x00FA, 0x003C, 0x0004, 0x00AC, 0x001A, 0x009F, 0x0004, 0x2FFD, 0x0048, 0x007C,
+        0x0004, 0x44CD, 0x00CA, 0x67FF, 0x0004, 0x1FFD, 0x002A, 0x444D, 0x0004, 0x00AD, 0x005A, 0x8CCF, 0x0004,
+        0x4FFD, 0x0048, 0x445D, 0x0004, 0x01BD, 0x008A, 0x4EEF, 0x0004, 0x45DD, 0x00FA, 0x111D, 0x0004, 0x009C,
+        0x001A, 0x222F, 0x0004, 0x8AED, 0x0048, 0x888D, 0x0004, 0x00DC, 0x00CA, 0xAFFF, 0x0004, 0xCFFD, 0x002A,
+        0x003D, 0x0004, 0x00BC, 0x005A, 0x11BF, 0x0004, 0x8FFD, 0x0048, 0x006C, 0x0004, 0x027D, 0x008A, 0x22EF,
+        0x0004, 0x00EC, 0x00FA, 0x003C, 0x0004, 0x00AC, 0x001A, 0x227F, 0x0004, 0x2FFD, 0x0048, 0x007C, 0x0004,
+        0x44CD, 0x00CA, 0x5DFF, 0x0004, 0x1FFD, 0x002A, 0x444D, 0x0004, 0x00AD, 0x005A, 0x006F, 0x0004, 0x4FFD,
+        0x0048, 0x445D, 0x0004, 0x01BD, 0x008A, 0x11DF, 0x0004, 0x45DD, 0x00FA, 0x111D, 0x0004, 0x009C, 0x001A,
+        0x155F, 0x0006, 0x00FC, 0x0018, 0x111D, 0x0048, 0x888D, 0x00AA, 0x4DDF, 0x0006, 0x2AAD, 0x005A, 0x67FF,
+        0x0028, 0x223D, 0x00BC, 0xAAAF, 0x0006, 0x00EC, 0x0018, 0x5FFF, 0x0048, 0x006C, 0x008A, 0xCCCF, 0x0006,
+        0x009D, 0x00CA, 0x44EF, 0x0028, 0x003C, 0x8FFD, 0x137F, 0x0006, 0x8EED, 0x0018, 0x1FFF, 0x0048, 0x007C,
+        0x00AA, 0x4CCF, 0x0006, 0x227D, 0x005A, 0x1DDF, 0x0028, 0x444D, 0x4FFD, 0x155F, 0x0006, 0x00DC, 0x0018,
+        0x2EEF, 0x0048, 0x445D, 0x008A, 0x22BF, 0x0006, 0x009C, 0x00CA, 0x8CDF, 0x0028, 0x222D, 0x2FFD, 0x226F,
+        0x0006, 0x00FC, 0x0018, 0x111D, 0x0048, 0x888D, 0x00AA, 0x1BBF, 0x0006, 0x2AAD, 0x005A, 0x33FF, 0x0028,
+        0x223D, 0x00BC, 0x8AAF, 0x0006, 0x00EC, 0x0018, 0x9BFF, 0x0048, 0x006C, 0x008A, 0x8ABF, 0x0006, 0x009D,
+        0x00CA, 0x4EEF, 0x0028, 0x003C, 0x8FFD, 0x466F, 0x0006, 0x8EED, 0x0018, 0xCFFF, 0x0048, 0x007C, 0x00AA,
+        0x8CCF, 0x0006, 0x227D, 0x005A, 0xAEEF, 0x0028, 0x444D, 0x4FFD, 0x477F, 0x0006, 0x00DC, 0x0018, 0xAFFF,
+        0x0048, 0x445D, 0x008A, 0x2BBF, 0x0006, 0x009C, 0x00CA, 0x44DF, 0x0028, 0x222D, 0x2FFD, 0x133F, 0x00F6,
+        0xAFFD, 0x1FFB, 0x003C, 0x0008, 0x23BD, 0x007A, 0x11DF, 0x00F6, 0x45DD, 0x2FFB, 0x4EEF, 0x00DA, 0x177D,
+        0xCFFD, 0x377F, 0x00F6, 0x3FFD, 0x8FFB, 0x111D, 0x0008, 0x009C, 0x005A, 0x1BBF, 0x00F6, 0x00CD, 0x00BA,
+        0x8DDF, 0x4FFB, 0x006C, 0x9BFD, 0x455F, 0x00F6, 0x67FD, 0x1FFB, 0x002C, 0x0008, 0x00AC, 0x007A, 0x009F,
+        0x00F6, 0x00AD, 0x2FFB, 0x7FFF, 0x00DA, 0x004C, 0x5FFD, 0x477F, 0x00F6, 0x00EC, 0x8FFB, 0x001C, 0x0008,
+        0x008C, 0x005A, 0x888F, 0x00F6, 0x00CC, 0x00BA, 0x2EEF, 0x4FFB, 0x115D, 0x8AED, 0x113F, 0x00F6, 0xAFFD,
+        0x1FFB, 0x003C, 0x0008, 0x23BD, 0x007A, 0x1DDF, 0x00F6, 0x45DD, 0x2FFB, 0xBFFF, 0x00DA, 0x177D, 0xCFFD,
+        0x447F, 0x00F6, 0x3FFD, 0x8FFB, 0x111D, 0x0008, 0x009C, 0x005A, 0x277F, 0x00F6, 0x00CD, 0x00BA, 0x22EF,
+        0x4FFB, 0x006C, 0x9BFD, 0x444F, 0x00F6, 0x67FD, 0x1FFB, 0x002C, 0x0008, 0x00AC, 0x007A, 0x11BF, 0x00F6,
+        0x00AD, 0x2FFB, 0xFFFF, 0x00DA, 0x004C, 0x5FFD, 0x233F, 0x00F6, 0x00EC, 0x8FFB, 0x001C, 0x0008, 0x008C,
+        0x005A, 0x006F, 0x00F6, 0x00CC, 0x00BA, 0x8BBF, 0x4FFB, 0x115D, 0x8AED, 0x222F};
+
+static const uint16_t dec_cxt_vlc_table0[1024] = {
+        0x0026, 0x00AA, 0x0046, 0x006C, 0x0086, 0x8AED, 0x0018, 0x8DDF, 0x0026, 0x01BD, 0x0046, 0x5FFF, 0x0086,
+        0x027D, 0x005A, 0x155F, 0x0026, 0x003A, 0x0046, 0x444D, 0x0086, 0x4CCD, 0x0018, 0xCCCF, 0x0026, 0x2EFD,
+        0x0046, 0x99FF, 0x0086, 0x009C, 0x00CA, 0x133F, 0x0026, 0x00AA, 0x0046, 0x445D, 0x0086, 0x8CCD, 0x0018,
+        0x11DF, 0x0026, 0x4FFD, 0x0046, 0xCFFF, 0x0086, 0x009D, 0x005A, 0x007E, 0x0026, 0x003A, 0x0046, 0x1FFF,
+        0x0086, 0x88AD, 0x0018, 0x00BE, 0x0026, 0x8FFD, 0x0046, 0x4EEF, 0x0086, 0x888D, 0x00CA, 0x111F, 0x0026,
+        0x00AA, 0x0046, 0x006C, 0x0086, 0x8AED, 0x0018, 0x45DF, 0x0026, 0x01BD, 0x0046, 0x22EF, 0x0086, 0x027D,
+        0x005A, 0x227F, 0x0026, 0x003A, 0x0046, 0x444D, 0x0086, 0x4CCD, 0x0018, 0x11BF, 0x0026, 0x2EFD, 0x0046,
+        0x00FE, 0x0086, 0x009C, 0x00CA, 0x223F, 0x0026, 0x00AA, 0x0046, 0x445D, 0x0086, 0x8CCD, 0x0018, 0x00DE,
+        0x0026, 0x4FFD, 0x0046, 0xABFF, 0x0086, 0x009D, 0x005A, 0x006F, 0x0026, 0x003A, 0x0046, 0x6EFF, 0x0086,
+        0x88AD, 0x0018, 0x2AAF, 0x0026, 0x8FFD, 0x0046, 0x00EE, 0x0086, 0x888D, 0x00CA, 0x222F, 0x0004, 0x00CA,
+        0x0088, 0x027D, 0x0004, 0x4CCD, 0x0028, 0x00FE, 0x0004, 0x2AFD, 0x0048, 0x005C, 0x0004, 0x009D, 0x0018,
+        0x00DE, 0x0004, 0x01BD, 0x0088, 0x006C, 0x0004, 0x88AD, 0x0028, 0x11DF, 0x0004, 0x8AED, 0x0048, 0x003C,
+        0x0004, 0x888D, 0x0018, 0x111F, 0x0004, 0x00CA, 0x0088, 0x006D, 0x0004, 0x88CD, 0x0028, 0x88FF, 0x0004,
+        0x8BFD, 0x0048, 0x444D, 0x0004, 0x009C, 0x0018, 0x00BE, 0x0004, 0x4EFD, 0x0088, 0x445D, 0x0004, 0x00AC,
+        0x0028, 0x00EE, 0x0004, 0x45DD, 0x0048, 0x222D, 0x0004, 0x003D, 0x0018, 0x007E, 0x0004, 0x00CA, 0x0088,
+        0x027D, 0x0004, 0x4CCD, 0x0028, 0x1FFF, 0x0004, 0x2AFD, 0x0048, 0x005C, 0x0004, 0x009D, 0x0018, 0x11BF,
+        0x0004, 0x01BD, 0x0088, 0x006C, 0x0004, 0x88AD, 0x0028, 0x22EF, 0x0004, 0x8AED, 0x0048, 0x003C, 0x0004,
+        0x888D, 0x0018, 0x227F, 0x0004, 0x00CA, 0x0088, 0x006D, 0x0004, 0x88CD, 0x0028, 0x4EEF, 0x0004, 0x8BFD,
+        0x0048, 0x444D, 0x0004, 0x009C, 0x0018, 0x2AAF, 0x0004, 0x4EFD, 0x0088, 0x445D, 0x0004, 0x00AC, 0x0028,
+        0x8DDF, 0x0004, 0x45DD, 0x0048, 0x222D, 0x0004, 0x003D, 0x0018, 0x155F, 0x0004, 0x005A, 0x0088, 0x006C,
+        0x0004, 0x88DD, 0x0028, 0x23FF, 0x0004, 0x11FD, 0x0048, 0x444D, 0x0004, 0x00AD, 0x0018, 0x00BE, 0x0004,
+        0x137D, 0x0088, 0x155D, 0x0004, 0x00CC, 0x0028, 0x00DE, 0x0004, 0x02ED, 0x0048, 0x111D, 0x0004, 0x009D,
+        0x0018, 0x007E, 0x0004, 0x005A, 0x0088, 0x455D, 0x0004, 0x44CD, 0x0028, 0x00EE, 0x0004, 0x1FFD, 0x0048,
+        0x003C, 0x0004, 0x00AC, 0x0018, 0x555F, 0x0004, 0x47FD, 0x0088, 0x113D, 0x0004, 0x02BD, 0x0028, 0x477F,
+        0x0004, 0x4CDD, 0x0048, 0x8FFF, 0x0004, 0x009C, 0x0018, 0x222F, 0x0004, 0x005A, 0x0088, 0x006C, 0x0004,
+        0x88DD, 0x0028, 0x00FE, 0x0004, 0x11FD, 0x0048, 0x444D, 0x0004, 0x00AD, 0x0018, 0x888F, 0x0004, 0x137D,
+        0x0088, 0x155D, 0x0004, 0x00CC, 0x0028, 0x8CCF, 0x0004, 0x02ED, 0x0048, 0x111D, 0x0004, 0x009D, 0x0018,
+        0x006F, 0x0004, 0x005A, 0x0088, 0x455D, 0x0004, 0x44CD, 0x0028, 0x1DDF, 0x0004, 0x1FFD, 0x0048, 0x003C,
+        0x0004, 0x00AC, 0x0018, 0x227F, 0x0004, 0x47FD, 0x0088, 0x113D, 0x0004, 0x02BD, 0x0028, 0x22BF, 0x0004,
+        0x4CDD, 0x0048, 0x22EF, 0x0004, 0x009C, 0x0018, 0x233F, 0x0006, 0x4DDD, 0x4FFB, 0xCFFF, 0x0018, 0x113D,
+        0x005A, 0x888F, 0x0006, 0x23BD, 0x008A, 0x00EE, 0x002A, 0x155D, 0xAAFD, 0x277F, 0x0006, 0x44CD, 0x8FFB,
+        0x44EF, 0x0018, 0x467D, 0x004A, 0x2AAF, 0x0006, 0x00AC, 0x555B, 0x99DF, 0x1FFB, 0x003C, 0x5FFD, 0x266F,
+        0x0006, 0x1DDD, 0x4FFB, 0x6EFF, 0x0018, 0x177D, 0x005A, 0x1BBF, 0x0006, 0x88AD, 0x008A, 0x5DDF, 0x002A,
+        0x444D, 0x2FFD, 0x667F, 0x0006, 0x00CC, 0x8FFB, 0x2EEF, 0x0018, 0x455D, 0x004A, 0x119F, 0x0006, 0x009C,
+        0x555B, 0x8CCF, 0x1FFB, 0x111D, 0x8CED, 0x006E, 0x0006, 0x4DDD, 0x4FFB, 0x3FFF, 0x0018, 0x113D, 0x005A,
+        0x11BF, 0x0006, 0x23BD, 0x008A, 0x8DDF, 0x002A, 0x155D, 0xAAFD, 0x222F, 0x0006, 0x44CD, 0x8FFB, 0x00FE,
+        0x0018, 0x467D, 0x004A, 0x899F, 0x0006, 0x00AC, 0x555B, 0x00DE, 0x1FFB, 0x003C, 0x5FFD, 0x446F, 0x0006,
+        0x1DDD, 0x4FFB, 0x9BFF, 0x0018, 0x177D, 0x005A, 0x00BE, 0x0006, 0x88AD, 0x008A, 0xCDDF, 0x002A, 0x444D,
+        0x2FFD, 0x007E, 0x0006, 0x00CC, 0x8FFB, 0x4EEF, 0x0018, 0x455D, 0x004A, 0x377F, 0x0006, 0x009C, 0x555B,
+        0x8BBF, 0x1FFB, 0x111D, 0x8CED, 0x233F, 0x0004, 0x00AA, 0x0088, 0x047D, 0x0004, 0x01DD, 0x0028, 0x11DF,
+        0x0004, 0x27FD, 0x0048, 0x005C, 0x0004, 0x8AAD, 0x0018, 0x2BBF, 0x0004, 0x009C, 0x0088, 0x006C, 0x0004,
+        0x00CC, 0x0028, 0x00EE, 0x0004, 0x8CED, 0x0048, 0x222D, 0x0004, 0x888D, 0x0018, 0x007E, 0x0004, 0x00AA,
+        0x0088, 0x006D, 0x0004, 0x88CD, 0x0028, 0x00FE, 0x0004, 0x19FD, 0x0048, 0x003C, 0x0004, 0x2AAD, 0x0018,
+        0xAAAF, 0x0004, 0x8BFD, 0x0088, 0x005D, 0x0004, 0x00BD, 0x0028, 0x4CCF, 0x0004, 0x44ED, 0x0048, 0x4FFF,
+        0x0004, 0x223D, 0x0018, 0x111F, 0x0004, 0x00AA, 0x0088, 0x047D, 0x0004, 0x01DD, 0x0028, 0x99FF, 0x0004,
+        0x27FD, 0x0048, 0x005C, 0x0004, 0x8AAD, 0x0018, 0x00BE, 0x0004, 0x009C, 0x0088, 0x006C, 0x0004, 0x00CC,
+        0x0028, 0x00DE, 0x0004, 0x8CED, 0x0048, 0x222D, 0x0004, 0x888D, 0x0018, 0x444F, 0x0004, 0x00AA, 0x0088,
+        0x006D, 0x0004, 0x88CD, 0x0028, 0x2EEF, 0x0004, 0x19FD, 0x0048, 0x003C, 0x0004, 0x2AAD, 0x0018, 0x447F,
+        0x0004, 0x8BFD, 0x0088, 0x005D, 0x0004, 0x00BD, 0x0028, 0x009F, 0x0004, 0x44ED, 0x0048, 0x67FF, 0x0004,
+        0x223D, 0x0018, 0x133F, 0x0006, 0x00CC, 0x008A, 0x9DFF, 0x2FFB, 0x467D, 0x1FFD, 0x99BF, 0x0006, 0x2AAD,
+        0x002A, 0x66EF, 0x4FFB, 0x005C, 0x2EED, 0x377F, 0x0006, 0x89BD, 0x004A, 0x00FE, 0x8FFB, 0x006C, 0x67FD,
+        0x889F, 0x0006, 0x888D, 0x001A, 0x5DDF, 0x00AA, 0x222D, 0x89DD, 0x444F, 0x0006, 0x2BBD, 0x008A, 0xCFFF,
+        0x2FFB, 0x226D, 0x009C, 0x00BE, 0x0006, 0xAAAD, 0x002A, 0x1DDF, 0x4FFB, 0x003C, 0x4DDD, 0x466F, 0x0006,
+        0x8AAD, 0x004A, 0xAEEF, 0x8FFB, 0x445D, 0x8EED, 0x177F, 0x0006, 0x233D, 0x001A, 0x4CCF, 0x00AA, 0xAFFF,
+        0x88CD, 0x133F, 0x0006, 0x00CC, 0x008A, 0x77FF, 0x2FFB, 0x467D, 0x1FFD, 0x3BBF, 0x0006, 0x2AAD, 0x002A,
+        0x00EE, 0x4FFB, 0x005C, 0x2EED, 0x007E, 0x0006, 0x89BD, 0x004A, 0x4EEF, 0x8FFB, 0x006C, 0x67FD, 0x667F,
+        0x0006, 0x888D, 0x001A, 0x00DE, 0x00AA, 0x222D, 0x89DD, 0x333F, 0x0006, 0x2BBD, 0x008A, 0x57FF, 0x2FFB,
+        0x226D, 0x009C, 0x199F, 0x0006, 0xAAAD, 0x002A, 0x99DF, 0x4FFB, 0x003C, 0x4DDD, 0x155F, 0x0006, 0x8AAD,
+        0x004A, 0xCEEF, 0x8FFB, 0x445D, 0x8EED, 0x277F, 0x0006, 0x233D, 0x001A, 0x1BBF, 0x00AA, 0x3FFF, 0x88CD,
+        0x111F, 0x0006, 0x45DD, 0x2FFB, 0x111D, 0x0018, 0x467D, 0x8FFD, 0xCCCF, 0x0006, 0x19BD, 0x004A, 0x22EF,
+        0x002A, 0x222D, 0x3FFD, 0x888F, 0x0006, 0x00CC, 0x008A, 0x00FE, 0x0018, 0x115D, 0xCFFD, 0x8AAF, 0x0006,
+        0x00AC, 0x003A, 0x8CDF, 0x1FFB, 0x133D, 0x66FD, 0x466F, 0x0006, 0x8CCD, 0x2FFB, 0x5FFF, 0x0018, 0x006C,
+        0x4FFD, 0xABBF, 0x0006, 0x22AD, 0x004A, 0x00EE, 0x002A, 0x233D, 0xAEFD, 0x377F, 0x0006, 0x2BBD, 0x008A,
+        0x55DF, 0x0018, 0x005C, 0x177D, 0x119F, 0x0006, 0x009C, 0x003A, 0x4CCF, 0x1FFB, 0x333D, 0x8EED, 0x444F,
+        0x0006, 0x45DD, 0x2FFB, 0x111D, 0x0018, 0x467D, 0x8FFD, 0x99BF, 0x0006, 0x19BD, 0x004A, 0x2EEF, 0x002A,
+        0x222D, 0x3FFD, 0x667F, 0x0006, 0x00CC, 0x008A, 0x4EEF, 0x0018, 0x115D, 0xCFFD, 0x899F, 0x0006, 0x00AC,
+        0x003A, 0x00DE, 0x1FFB, 0x133D, 0x66FD, 0x226F, 0x0006, 0x8CCD, 0x2FFB, 0x9BFF, 0x0018, 0x006C, 0x4FFD,
+        0x00BE, 0x0006, 0x22AD, 0x004A, 0x1DDF, 0x002A, 0x233D, 0xAEFD, 0x007E, 0x0006, 0x2BBD, 0x008A, 0xCEEF,
+        0x0018, 0x005C, 0x177D, 0x277F, 0x0006, 0x009C, 0x003A, 0x8BBF, 0x1FFB, 0x333D, 0x8EED, 0x455F, 0x1FF9,
+        0x1DDD, 0xAFFB, 0x00DE, 0x8FF9, 0x001C, 0xFFFB, 0x477F, 0x4FF9, 0x177D, 0x3FFB, 0x3BBF, 0x2FF9, 0xAEEF,
+        0x8EED, 0x444F, 0x1FF9, 0x22AD, 0x000A, 0x8BBF, 0x8FF9, 0x00FE, 0xCFFD, 0x007E, 0x4FF9, 0x115D, 0x5FFB,
+        0x577F, 0x2FF9, 0x8DDF, 0x2EED, 0x333F, 0x1FF9, 0x2BBD, 0xAFFB, 0x88CF, 0x8FF9, 0xBFFF, 0xFFFB, 0x377F,
+        0x4FF9, 0x006D, 0x3FFB, 0x00BE, 0x2FF9, 0x66EF, 0x9FFD, 0x133F, 0x1FF9, 0x009D, 0x000A, 0xABBF, 0x8FF9,
+        0xDFFF, 0x6FFD, 0x006E, 0x4FF9, 0x002C, 0x5FFB, 0x888F, 0x2FF9, 0xCDDF, 0x4DDD, 0x222F, 0x1FF9, 0x1DDD,
+        0xAFFB, 0x4CCF, 0x8FF9, 0x001C, 0xFFFB, 0x277F, 0x4FF9, 0x177D, 0x3FFB, 0x99BF, 0x2FF9, 0xCEEF, 0x8EED,
+        0x004E, 0x1FF9, 0x22AD, 0x000A, 0x00AE, 0x8FF9, 0x7FFF, 0xCFFD, 0x005E, 0x4FF9, 0x115D, 0x5FFB, 0x009E,
+        0x2FF9, 0x5DDF, 0x2EED, 0x003E, 0x1FF9, 0x2BBD, 0xAFFB, 0x00CE, 0x8FF9, 0xEFFF, 0xFFFB, 0x667F, 0x4FF9,
+        0x006D, 0x3FFB, 0x8AAF, 0x2FF9, 0x00EE, 0x9FFD, 0x233F, 0x1FF9, 0x009D, 0x000A, 0x1BBF, 0x8FF9, 0x4EEF,
+        0x6FFD, 0x455F, 0x4FF9, 0x002C, 0x5FFB, 0x008E, 0x2FF9, 0x99DF, 0x4DDD, 0x111F};
diff --git a/libavcodec/jpeg2000htdec.h b/libavcodec/jpeg2000htdec.h
new file mode 100644
index 0000000000..572d095c92
--- /dev/null
+++ b/libavcodec/jpeg2000htdec.h
@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2022 Caleb Etemesi <etemesicaleb@gmail.com>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVCODEC_JPEG2000HTDEC_H
+#define AVCODEC_JPEG2000HTDEC_H
+
+#include "jpeg2000dec.h"
+
+/**
+ * HT Block decoder as specified in Rec. ITU-T T.814 | ISO/IEC 15444-15
+ */
+
+int ff_jpeg2000_decode_htj2k(const Jpeg2000DecoderContext *s, Jpeg2000CodingStyle *codsty,
+                            Jpeg2000T1Context *t1, Jpeg2000Cblk *cblk, int width,
+                            int height, int magp, uint8_t roi_shift);
+
+#endif /* AVCODEC_JPEG2000HTDEC_H */