[FFmpeg-devel] [PATCH 2/2] avcodec/jpeg2000dec: Add support for High Throughput HTJ2K decoding.
Caleb Etemesi
etemesicaleb at gmail.com
Fri Dec 16 17:41:51 EET 2022
Hi Andreas, thanks for the review,
> Use "" instead of <>.
Will do
> I really don't like that you are adding a new bitreader here. Can you
explain why this is supposed to be necessary?
The reasons are:
1. The spec has some byte streams read from back to front,I didn't see that
functionality present in get_bits.h(which I assumed contained the bit
reading API).
2. It doesn't handle unstuffing correctly.
3. Doesn't handle EOB correctly, the spec has some arrays when there are no
more bytes, the bit-reader should be filled with 0, others with 0xFF.
> Generally, it is not ok to read array[-1] even if the result is that is
> vmasked 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.
Hi that is the case, the stream in question is a backward read array, hence
array[-1] would point to the last byte in the MEL
byte stream which is forward read, the paper on HTJ2K @
https://www.htj2k.com/wp-content/uploads/white-paper.pdf on page 20 shows
an image description
of how the bytes are arranged.
> Branchlessly? I see four branches below.
Sorry stray comment, will remove
> 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.
This array[-1] covered by the MEL bytestream, but a solution would be to
have a check to see if we are close to the end
Didn't know about AV_RB32, replaced the manual shifts with it.
> Are you sure you want to have <= instead of < here? This could read
> length + 1 bytes of array.
Yes, this is that way because of a bug Tomas Hardin found in the first
iteration of the patches.
> Why is this av_noinline? It is normally good, to inline functions only
> called once.
Will change.
> Why does a function called jpeg2000_decode_ht_cleanup perform
> allocations? And why all the other stuff below?
It decodes the cleanup segment, it's not a cleanup function.
> Could use a smaller scope.
Hi what exactly ? the whole code below that?
> This is inconsistent with our naming conventions.
Hi, what section of the naming conventions?
> 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.
Sounds like a good idea,
On Fri, Dec 16, 2022 at 3:29 AM Andreas Rheinhardt <
andreas.rheinhardt at outlook.com> wrote:
> 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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