[FFmpeg-devel] [PATCH 2/2] avcodec/jpeg2000dec: Add support for High Throughput HTJ2K decoding.
Andreas Rheinhardt
andreas.rheinhardt at outlook.com
Fri Dec 16 02:29:16 EET 2022
etemesicaleb at gmail.com:
> From: caleb <etemesicaleb at gmail.com>
>
> This is a revised patch with suggested changes from earlier and satisfies the Google Summer of
> Code 2022 FFmpeg project to add a HTJ2K decoder to FFmpeg.
>
> ---
> libavcodec/Makefile | 2 +-
> libavcodec/jpeg2000.h | 3 +
> libavcodec/jpeg2000dec.c | 69 +-
> libavcodec/jpeg2000dec.h | 2 +
> libavcodec/jpeg2000htdec.c | 1441 ++++++++++++++++++++++++++++++++++++
> libavcodec/jpeg2000htdec.h | 28 +
> 6 files changed, 1529 insertions(+), 16 deletions(-)
> create mode 100644 libavcodec/jpeg2000htdec.c
> create mode 100644 libavcodec/jpeg2000htdec.h
>
> diff --git a/libavcodec/Makefile b/libavcodec/Makefile
> index 98841ed07c..1ba9e09528 100644
> --- a/libavcodec/Makefile
> +++ b/libavcodec/Makefile
> @@ -464,7 +464,7 @@ 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..b2a8e13244 100644
> --- a/libavcodec/jpeg2000.h
> +++ b/libavcodec/jpeg2000.h
> @@ -189,6 +189,9 @@ typedef struct Jpeg2000Cblk {
> Jpeg2000Pass *passes;
> Jpeg2000Layer *layers;
> int coord[2][2]; // border coordinates {{x0, x1}, {y0, y1}}
> + /*HTJ2K settings */
> + int zbp;
> + int pass_lengths[2];
> } Jpeg2000Cblk; // code block
>
> typedef struct Jpeg2000Prec {
> diff --git a/libavcodec/jpeg2000dec.c b/libavcodec/jpeg2000dec.c
> index 7fc09cb558..5c92baa88e 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"
>
> /* get_bits functions for JPEG2000 packet bitstream
> * It is a get_bit function with a bit-stuffing routine. If the value of the
> @@ -428,12 +429,13 @@ 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");
> + s->is_htj2k = 1;
> + } 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 */
> @@ -1058,13 +1060,15 @@ 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)
> @@ -1105,8 +1109,29 @@ 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 && s->is_htj2k) {
> + // Retrieve pass lengths for each pass
> + int href_passes = (cblk->npasses + newpasses - 1) % 3;
> + int segment_passes = newpasses - href_passes;
> + int pass_bound = 2;
> + int eb = 0;
> + int extra_bit = newpasses > 2 ? 1 : 0;
> + while (pass_bound <=segment_passes) {
> + eb++;
> + pass_bound +=pass_bound;
> + }
> + 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);
> @@ -1857,7 +1882,10 @@ static inline void tile_codeblocks(const Jpeg2000DecoderContext *s, Jpeg2000Tile
> for (compno = 0; compno < s->ncomponents; 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;
>
> @@ -1865,7 +1893,7 @@ 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;
> @@ -1885,12 +1913,23 @@ 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;
> + // Annex E (Equation E-2) ISO/IEC 15444-1:2019
> + 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 (s->is_htj2k)
> + 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/jpeg2000dec.h b/libavcodec/jpeg2000dec.h
> index b6410c1432..9728529026 100644
> --- a/libavcodec/jpeg2000dec.h
> +++ b/libavcodec/jpeg2000dec.h
> @@ -121,6 +121,8 @@ typedef struct Jpeg2000DecoderContext {
>
> /*options parameters*/
> int reduction_factor;
> + /*HTJ2K params*/
> + uint8_t is_htj2k;
> } Jpeg2000DecoderContext;
>
> #endif //AVCODEC_JPEG2000DEC_H
> diff --git a/libavcodec/jpeg2000htdec.c b/libavcodec/jpeg2000htdec.c
> new file mode 100644
> index 0000000000..8ea901855f
> --- /dev/null
> +++ b/libavcodec/jpeg2000htdec.c
> @@ -0,0 +1,1441 @@
> +/*
> + * Copyright (c) 2022 Caleb Etemesi <etemesicaleb at 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
> + */
> +#include "jpeg2000htdec.h"
> +#include "jpeg2000.h"
> +#include "jpeg2000dec.h"
> +#include <stdint.h>
> +#include <libavutil/attributes.h>
> +#include <libavutil/common.h>
> +#include <libavutil/avassert.h>
Use "" instead of <>.
> +
> +#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
> +/**
> + * @brief Table 2 in clause 7.3.3
> + */
> +const static uint8_t MEL_E[13] = {0, 0, 0, 1, 1, 1, 2, 2, 2, 3, 3, 4, 5};
> +// Decode tables, found at the end of this
> +static const uint16_t dec_CxtVLC_table1[1024];
> +static const uint16_t dec_CxtVLC_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;
> +
I really don't like that you are adding a new bitreader here. Can you
explain why this is supposed to be necessary?
> +typedef struct MelDecoderState {
> + uint8_t k;
> + uint8_t run;
> + uint8_t one;
> +} MelDecoderState;
> +
> +/**
> + * Given a precomputed c, checks whether n % d == 0
> + *
> + * precomputed c for d is created by the precompute_c function
> + */
> +static av_always_inline uint32_t is_divisible(uint32_t n, uint64_t c)
> +{
> + return n * c <= c - 1;
> +}
> +/**
> + * Precompute a number c given d that when combined with a dividend n
> + * returns whether n % d == 0
> + *
> + * Combined with is_divisible function
> + */
> +static av_always_inline uint64_t precompute_c(uint32_t divisor)
> +{
> +
> + return 1 + (0xfffffffffffffffful / divisor);
> +}
> +/* Initializers */
> +
> +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;
> +}
> +
> +/**
> + * @brief 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;
> + uint32_t mask;
> +
> + if (buffer->bits_left > 32)
> + return 0; // enough data, no need to pull in more bits
> +
> + /*
> + * We are reading bits from end to start, and we need to handle them in LE.
> + * therefore, if we read bytes ABCD, we need to convert
> + * them to DCBA, but the bitstream is constructed in such a way that it is
> + * BE when reading from back to front,so we need to swap bytes
> + * but this doesn't work when position is less than 3,
> + * we end up reading bits from the MEL byte-stream which
> + * is a recipe for sleepless nights.
> + *
> + * So the trick is to branchlessly read and mask
> + * depending on whatever was the initial position,
> + * the mask is simply either 32 bits, 24 bits ,8 bits or 0 bits.
> + * depending on how many bytes are available, with this, we don't
> + * read past the end of the buffer,we mask
> + * bits we already read ensuring we don't read twice.
> + * and we can do it branchlessly without checking for positions.
Generally, it is not ok to read array[-1] even if the result is that is
masked away later. It is ok if array actually points into the middle of
a buffer, so that array[-1] and the other bytes accessed are actually
part of the buffer. Your remark about MEL bytestream indicates that this
might be the case here, but I'm not sure.
> + *
> + * We need to watch out for negative shift values which are UB in C hence
> + * the MAX declarative.
> + */
> +
> + position -= 4;
> + mask = (UINT64_C(1) << (FFMIN(4, buffer->pos + 1)) * 8) - 1;
In case buffer->pos + 1 < 4, position + 1 < 0 and therefore the next
lines will read array[-1]. And given that you are using FFMIN, there is
an implicit branch anyway. I suggest you use AV_RB32 to read only from a
position that is known to be in the buffer and then shift unwanted bytes
away.
> + tmp = array[position + 1] * (1ull << 24);
(uint32_t)array[position + 1] << 24 works as well and avoids the 64bit
intermediate and the multiplication hack.
> + tmp |= array[position + 2] << 16;
> + tmp |= array[position + 3] << 8;
> + tmp |= array[position + 4];
> + tmp &= mask;
> +
> + // Branchlessly unstuff bits
Branchlessly? I see four branches below.
> +
> + // load temporary byte, which preceeds 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--;
> + }
> + /* remove temporary byte loaded. */
> + tmp >>= 8;
> +
> + /* 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;
> +}
> +
> +/**
> + * @brief 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) {
Are you sure you want to have <= instead of < here? This could read
length + 1 bytes of array.
> + 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;
> + }
> +}
> +
> +/**
> + * @brief Drops bits from lower bits in the bit buffer
> + *
> + * @param buf: Struct containing bit buffers
> + * @param nbits: Number of bits to remove.
> + */
> +static av_always_inline void jpeg2000_bitbuf_drop_bits_lsb(StateVars *buf,
> + uint8_t nbits)
> +{
> + if (buf->bits_left < nbits) {
> + av_log(NULL, AV_LOG_ERROR, "Invalid bit read of %d, bits in buffer are %d\n", nbits, buf->bits_left);
> + av_assert0(0);
> + }
> + buf->bit_buf >>= nbits;
> + buf->bits_left -= nbits;
> +}
> +
> +/**
> + * @brief 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.
> + */
> +static av_always_inline 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;
> +}
> +
> +/**
> + * @brief 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
> + */
> +static av_always_inline 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;
> +}
> +
> +/**
> + * @brief Look ahead bit buffer without discarding bits
> + */
> +static av_always_inline uint64_t jpeg2000_bitbuf_peek_bits_lsb(StateVars *stream, uint8_t nbits)
> +{
> + uint64_t mask = (1ull << nbits) - 1;
> + return stream->bit_buf & mask;
> +}
> +
> +/**
> + * Variable Length Decoding Routines
> + */
> +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.
> + */
> +static int av_always_inline 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)
> +{
> + /* Described in clause 7.3.5 */
> + 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);
> +
> + /* decode table has 1024 entries so ensure array access is in bounds */
> + av_assert0(index < 1024);
> +
> + 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;
> +}
> +
> +/**
> + * @brief Decode variable length u-vlc prefix
> + */
> +static av_always_inline uint8_t
> +vlc_decode_u_prefix(StateVars *vlc_stream, const uint8_t *refill_array)
> +{
> + /* clause 7.3.6
> + * procedure : decodeUPrefix.
> + */
> + 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];
> +}
> +
> +/**
> + * @brief Decode variable length u-vlc suffix
> + */
> +static av_always_inline uint8_t vlc_decode_u_suffix(
> + StateVars *vlc_stream, uint8_t suffix, const uint8_t *refill_array)
> +{
> + /* clause 7.3.6
> + * procedure: decodeUSuffix
> + */
> + 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];
> +}
> +
> +/**
> + * @brief Decode variable length u-vlc suffix
> + */
> +static av_always_inline uint8_t vlc_decode_u_extension(
> + StateVars *vlc_stream, uint8_t suffix, const uint8_t *refill_array)
> +{
> + /* clause 7.3.6
> + * procedure decodeUExtension.
> + */
> + return jpeg2000_bitbuf_get_bits_lsb(vlc_stream, 4 * (suffix >= 28), refill_array);
> +}
> +
> +/**
> + * Magnitude and Sign decode procedures
> + */
> +static int32_t av_always_inline jpeg2000_decode_mag_sgn(StateVars *mag_sgn_stream, int32_t m_n,
> + int32_t i_n, const uint8_t *buf, uint32_t length)
> +{
> + /* clause 7.3.8
> + * procedure: decodeMagSgnValue
> + */
> + 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;
> +}
> +
> +static av_always_inline 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;
> + }
> +}
> +
> +/**
> + * @brief Magref decoding procedures
> + */
> +static av_always_inline int jpeg2000_import_magref_bit(StateVars *stream, const uint8_t *array, uint32_t length)
> +{
> + return jpeg2000_bitbuf_get_bits_lsb(stream, 1, array);
> +}
> +
> +/**
> + * @brief 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);
> +}
> +
> +static av_always_inline 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;
> +}
> +
> +static av_always_inline 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;
> +}
> +
> +static int av_noinline
Why is this av_noinline? It is normally good, to inline functions only
called once.
> +jpeg2000_decode_ht_cleanup(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 (7.3.7) */
> + 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;
> +
> + int j1, j2;
> + int x1 = 0, x2 = 0, x3 = 0;
> +
> + 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));
> +
Why does a function called jpeg2000_decode_ht_cleanup perform
allocations? And why all the other stuff below?
> + 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_CxtVLC_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_CxtVLC_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);
> + }
> + // clause 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);
> +
> + // prepare context for the next quad
> +
> + // move to the next quad pair
> + q += 2;
> + }
> + if (quad_width % 2 == 1) {
> + q1 = q;
> +
> + if ((ret = jpeg2000_decode_sig_emb(s, mel_state, mel_stream, vlc_stream,
> + dec_CxtVLC_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:
> + * 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 we can't have a quad being zero, the spec doesn't allow,
> + * 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_CxtVLC_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_CxtVLC_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);
> +
> + /* move to the next quad pair */
> + q += 2;
> + }
> + 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_CxtVLC_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++) {
> + 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)
> +{
> + int32_t *sp;
> + uint8_t causal_cond = 0;
> + uint8_t bit;
> + uint8_t mbr;
> + uint32_t mbr_info;
> + int modify_state = 0;
> + int cond;
> +
> + for (int j = j_s; j < j_s + width; j++) {
> + mbr_info = 0;
Could use a smaller scope.
> + for (int i = i_s; i < i_s + height; i++) {
> + sp = &sample_buf[j + (i * (stride - 2))];
> + mbr = 0;
> + causal_cond = i != (i_s + height - 1);
> + 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);
> + }
> + }
> +}
> +
> +static void av_noinline
> +jpeg2000_decode_sigprop(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)
> +{
> + /* Described in clause 7.4
> + * procedure: decodeSigPropMag
> + */
> + 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);
> +}
> +
> +static int av_noinline
> +jpeg2000_decode_magref(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)
> +{
> + /*
> + * Described in clause 7.5
> + * procedure: decodeSigPropMag
> + */
> +
> + 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 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;
> +
> + /* Post-processing */
> + int32_t n, val;
> +
> + int32_t M_b = magp;
> + 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)
> + /* no passes within this set, continue */
> + return 0;
> +
> + 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 comes after the refinement segment. */
> + Dref = cblk->data + Lcup;
> + 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(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(cblk, width, height, Dref, Lref,
> + pLSB - 1, sample_buf, block_states);
> +
> + if (cblk->npasses > 2)
> + if ((ret = jpeg2000_decode_magref(cblk, width, height, Dref, Lref,
> + pLSB - 1, sample_buf, block_states))
> + < 0)
> + goto free;
> +
> + pLSB = 31 - M_b;
> + /* Reconstruct the 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 twos 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;
> +}
> +
> +/**
> + * @brief CtxVLC tables, borrowed from openhtj2k (https://github.com/osamu620/OpenHTJ2K) (credits to Osamu Watanabe)
> + */
> +static const uint16_t dec_CxtVLC_table1[1024] = {
This is inconsistent with our naming conventions.
> + 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_CxtVLC_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..62cf1450c2
> --- /dev/null
> +++ b/libavcodec/jpeg2000htdec.h
> @@ -0,0 +1,28 @@
> +/*
> +* JPEG2000 High Throughput block decoder
> +* Copyright (c) 2022 Caleb Etemesi <etemesicaleb at 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"
> +
> +int ff_jpeg2000_decode_htj2k(const Jpeg2000DecoderContext *s, Jpeg2000CodingStyle *codsty, Jpeg2000T1Context *t1, Jpeg2000Cblk *cblk, int width, int height, int magp, uint8_t roi_shift);
> +
jpeg2000dec.c seems to be the only intended user of this function, so
one could make a header/template out of jpeg2000htdec.c and include this
in jpeg2000dec.c. This would allow to make this function static and
would avoid exposing the jpeg2000dec.c structures via a header.
> +#endif /* AVCODEC_JPEG2000HTDEC_H */
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