[FFmpeg-devel] [PATCH 1/2] avcodec/jpeg2000dec: Add support for placeholder passes, CAP, and CPF markers

Pierre-Anthony Lemieux pal at sandflow.com
Sat Jun 15 09:00:21 EEST 2024


Hi Osamu,

Can you provide the list of J2K reference codestreams that this code
allows FFMPEG to support -- not including those already supported [1]?

[1] https://github.com/FFmpeg/FFmpeg/blob/master/tests/fate/jpeg2000.mak

Best,

-- Pierre

On Fri, Jun 14, 2024 at 8:15 PM Osamu Watanabe
<owatanab at es.takushoku-u.ac.jp> wrote:
>
> Signed-off-by: Osamu Watanabe <owatanab at es.takushoku-u.ac.jp>
> ---
>  libavcodec/jpeg2000.h      |  10 +
>  libavcodec/jpeg2000dec.c   | 454 ++++++++++++++++++++++++++++++-------
>  libavcodec/jpeg2000dec.h   |   7 +
>  libavcodec/jpeg2000htdec.c | 225 ++++++++++--------
>  libavcodec/jpeg2000htdec.h |   2 +-
>  5 files changed, 518 insertions(+), 180 deletions(-)
>
> diff --git a/libavcodec/jpeg2000.h b/libavcodec/jpeg2000.h
> index d004c08f10..93221d90ca 100644
> --- a/libavcodec/jpeg2000.h
> +++ b/libavcodec/jpeg2000.h
> @@ -37,12 +37,14 @@
>
>  enum Jpeg2000Markers {
>      JPEG2000_SOC = 0xff4f, // start of codestream
> +    JPEG2000_CAP = 0xff50, // extended capabilities
>      JPEG2000_SIZ = 0xff51, // image and tile size
>      JPEG2000_COD,          // coding style default
>      JPEG2000_COC,          // coding style component
>      JPEG2000_TLM = 0xff55, // tile-part length, main header
>      JPEG2000_PLM = 0xff57, // packet length, main header
>      JPEG2000_PLT,          // packet length, tile-part header
> +    JPEG2000_CPF,          // corresponding profile
>      JPEG2000_QCD = 0xff5c, // quantization default
>      JPEG2000_QCC,          // quantization component
>      JPEG2000_RGN,          // region of interest
> @@ -58,6 +60,12 @@ enum Jpeg2000Markers {
>      JPEG2000_EOC = 0xffd9, // end of codestream
>  };
>
> +enum JPEG2000_Ccap15_b14_15_params {
> +    HTJ2K_HTONLY = 0,      // HTONLY, bit 14 and 15 are 0
> +    HTJ2K_HTDECLARED,      // HTDECLARED, bit 14 = 1 and bit 15 = 0
> +    HTJ2K_MIXED = 3,       // MIXED, bit 14 and 15 are 1
> +};
> +
>  #define JPEG2000_SOP_FIXED_BYTES 0xFF910004
>  #define JPEG2000_SOP_BYTE_LENGTH 6
>
> @@ -192,6 +200,8 @@ typedef struct Jpeg2000Cblk {
>      /* specific to HT code-blocks */
>      int zbp;
>      int pass_lengths[2];
> +    uint8_t modes; // copy of SPcod/SPcoc field to parse HT-MIXED mode
> +    uint8_t ht_plhd; // are we looking for HT placeholder passes?
>  } Jpeg2000Cblk; // code block
>
>  typedef struct Jpeg2000Prec {
> diff --git a/libavcodec/jpeg2000dec.c b/libavcodec/jpeg2000dec.c
> index d15502a527..d299c67cc7 100644
> --- a/libavcodec/jpeg2000dec.c
> +++ b/libavcodec/jpeg2000dec.c
> @@ -54,6 +54,15 @@
>  #define HAD_COC 0x01
>  #define HAD_QCC 0x02
>
> +// Values of flag for placeholder passes
> +enum HT_PLHD_STATUS {
> +    HT_PLHD_OFF,
> +    HT_PLHD_ON
> +};
> +
> +#define HT_MIXED 0x80 // bit 7 of SPcod/SPcoc
> +
> +
>  /* get_bits functions for JPEG2000 packet bitstream
>   * It is a get_bit function with a bit-stuffing routine. If the value of the
>   * byte is 0xFF, the next byte includes an extra zero bit stuffed into the MSB.
> @@ -382,6 +391,9 @@ static int get_siz(Jpeg2000DecoderContext *s)
>          } else if (ncomponents == 1 && s->precision == 8) {
>              s->avctx->pix_fmt = AV_PIX_FMT_GRAY8;
>              i = 0;
> +        } else if (ncomponents == 1 && s->precision == 12) {
> +            s->avctx->pix_fmt = AV_PIX_FMT_GRAY16LE;
> +            i = 0;
>          }
>      }
>
> @@ -408,6 +420,73 @@ static int get_siz(Jpeg2000DecoderContext *s)
>      s->avctx->bits_per_raw_sample = s->precision;
>      return 0;
>  }
> +/* get extended capabilities (CAP) marker segment */
> +static int get_cap(Jpeg2000DecoderContext *s, Jpeg2000CodingStyle *c)
> +{
> +    uint32_t Pcap;
> +    uint16_t Ccap_i[32] = { 0 };
> +    uint16_t Ccap_15;
> +    uint8_t P;
> +
> +    if (bytestream2_get_bytes_left(&s->g) < 6) {
> +        av_log(s->avctx, AV_LOG_ERROR, "Insufficient space for CAP\n");
> +        return AVERROR_INVALIDDATA;
> +    }
> +
> +    Pcap = bytestream2_get_be32u(&s->g);
> +    s->isHT = (Pcap >> (31 - (15 - 1))) & 1;
> +    for (int i = 0; i < 32; i++) {
> +        if ((Pcap >> (31 - i)) & 1)
> +            Ccap_i[i] = bytestream2_get_be16u(&s->g);
> +    }
> +    Ccap_15 = Ccap_i[14];
> +    if (s->isHT == 1) {
> +    av_log(s->avctx, AV_LOG_INFO, "This is an HTJ2K codestream.\n");
> +    // Bits 14-15
> +    switch ((Ccap_15 >> 14) & 0x3) {
> +        case 0x3:
> +            s->Ccap15_b14_15 = HTJ2K_MIXED;
> +            break;
> +        case 0x1:
> +            s->Ccap15_b14_15 = HTJ2K_HTDECLARED;
> +            break;
> +        case 0x0:
> +            s->Ccap15_b14_15 = HTJ2K_HTONLY;
> +            break;
> +        default:
> +                av_log(s->avctx, AV_LOG_ERROR, "Unknown CCap value.\n");
> +            return AVERROR(EINVAL);
> +            break;
> +    }
> +    // Bit 13
> +    if ((Ccap_15 >> 13) & 1) {
> +        av_log(s->avctx, AV_LOG_ERROR, "MULTIHT set is not supported.\n");
> +        return AVERROR_PATCHWELCOME;
> +    }
> +    // Bit 12
> +    s->Ccap15_b12 = (Ccap_15 >> 12) & 1;
> +    // Bit 11
> +    s->Ccap15_b11 = (Ccap_15 >> 11) & 1;
> +    // Bit 5
> +    s->Ccap15_b05 = (Ccap_15 >> 5) & 1;
> +    // Bit 0-4
> +    P = Ccap_15 & 0x1F;
> +    if (!P)
> +        s->HT_MAGB = 8;
> +    else if (P < 20)
> +        s->HT_MAGB = P + 8;
> +    else if (P < 31)
> +        s->HT_MAGB = 4 * (P - 19) + 27;
> +    else
> +        s->HT_MAGB = 74;
> +
> +    if (s->HT_MAGB > 31) {
> +            av_log(s->avctx, AV_LOG_ERROR, "Available internal precision is exceeded (MAGB> 31).\n");
> +        return AVERROR_PATCHWELCOME;
> +    }
> +    }
> +    return 0;
> +}
>
>  /* get common part for COD and COC segments */
>  static int get_cox(Jpeg2000DecoderContext *s, Jpeg2000CodingStyle *c)
> @@ -802,6 +881,15 @@ static int read_crg(Jpeg2000DecoderContext *s, int n)
>      bytestream2_skip(&s->g, n - 2);
>      return 0;
>  }
> +
> +static int read_cpf(Jpeg2000DecoderContext *s, int n)
> +{
> +    if (bytestream2_get_bytes_left(&s->g) < (n - 2))
> +        return AVERROR_INVALIDDATA;
> +    bytestream2_skip(&s->g, n - 2);
> +    return 0;
> +}
> +
>  /* Tile-part lengths: see ISO 15444-1:2002, section A.7.1
>   * Used to know the number of tile parts and lengths.
>   * There may be multiple TLMs in the header.
> @@ -965,6 +1053,10 @@ static int init_tile(Jpeg2000DecoderContext *s, int tileno)
>              comp->roi_shift = s->roi_shift[compno];
>          if (!codsty->init)
>              return AVERROR_INVALIDDATA;
> +        if (s->isHT && (!s->Ccap15_b05) && (!codsty->transform))
> +            av_log(s->avctx, AV_LOG_WARNING, "Transformation = 0 (lossy DWT) is found in HTREV HT set\n");
> +        if (s->isHT && s->Ccap15_b14_15 != (codsty->cblk_style >> 6) && s->Ccap15_b14_15 != HTJ2K_HTONLY)
> +            av_log(s->avctx, AV_LOG_WARNING, "SPcod/SPcoc value does not match bit 14-15 values of Ccap15\n");
>          if (ret = ff_jpeg2000_init_component(comp, codsty, qntsty,
>                                               s->cbps[compno], s->cdx[compno],
>                                               s->cdy[compno], s->avctx))
> @@ -1067,100 +1159,275 @@ static int jpeg2000_decode_packet(Jpeg2000DecoderContext *s, Jpeg2000Tile *tile,
>              int incl, newpasses, llen;
>              void *tmp;
>
> -            if (cblk->npasses)
> -                incl = get_bits(s, 1);
> -            else
> +            if (!cblk->incl) {
> +                incl = 0;
> +                cblk->modes = codsty->cblk_style;
> +                if (cblk->modes >= JPEG2000_CTSY_HTJ2K_F)
> +                    cblk->ht_plhd = HT_PLHD_ON;
> +                if (layno > 0)
> +                    incl = tag_tree_decode(s, prec->cblkincl + cblkno, 0 + 1) == 0;
>                  incl = tag_tree_decode(s, prec->cblkincl + cblkno, layno + 1) == layno;
> -            if (!incl)
> -                continue;
> -            else if (incl < 0)
> -                return incl;
> -
> -            if (!cblk->npasses) {
> -                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;
> +                if (incl) {
> +                    int zbp = tag_tree_decode(s, prec->zerobits + cblkno, 100);
> +                    int v = expn[bandno] + numgbits - 1 - (zbp - tile->comp->roi_shift);
> +                    if (v < 0 || v > 30) {
> +                        av_log(s->avctx, AV_LOG_ERROR,
> +                               "nonzerobits %d invalid or unsupported\n", v);
> +                        return AVERROR_INVALIDDATA;
> +                    }
> +                    cblk->incl = 1;
> +                    cblk->nonzerobits = v;
> +                    cblk->zbp = zbp;
> +                    cblk->lblock = 3;
>                  }
> -                cblk->zbp = zbp;
> -                cblk->nonzerobits = v;
> -            }
> -            if ((newpasses = getnpasses(s)) < 0)
> -                return newpasses;
> -            av_assert2(newpasses > 0);
> -            if (cblk->npasses + newpasses >= JPEG2000_MAX_PASSES) {
> -                avpriv_request_sample(s->avctx, "Too many passes");
> -                return AVERROR_PATCHWELCOME;
> -            }
> -            if ((llen = getlblockinc(s)) < 0)
> -                return llen;
> -            if (cblk->lblock + llen + av_log2(newpasses) > 16) {
> -                avpriv_request_sample(s->avctx,
> -                                      "Block with length beyond 16 bits");
> -                return AVERROR_PATCHWELCOME;
> +            } else {
> +                incl = get_bits(s, 1);
>              }
>
> -            cblk->lblock += llen;
> -
> -            cblk->nb_lengthinc = 0;
> -            cblk->nb_terminationsinc = 0;
> -            av_free(cblk->lengthinc);
> -            cblk->lengthinc = av_calloc(newpasses, sizeof(*cblk->lengthinc));
> -            if (!cblk->lengthinc)
> -                return AVERROR(ENOMEM);
> -            tmp = av_realloc_array(cblk->data_start, cblk->nb_terminations + newpasses + 1, sizeof(*cblk->data_start));
> -            if (!tmp)
> -                return AVERROR(ENOMEM);
> -            cblk->data_start = tmp;
> -            do {
> -                int newpasses1 = 0;
> -
> -                while (newpasses1 < newpasses) {
> -                    newpasses1 ++;
> -                    if (needs_termination(codsty->cblk_style, cblk->npasses + newpasses1 - 1)) {
> -                        cblk->nb_terminationsinc ++;
> -                        break;
> +            if (incl) {
> +                uint8_t bypass_term_threshold = 0;
> +                uint8_t bits_to_read = 0;
> +                uint32_t segment_bytes = 0;
> +                int32_t segment_passes = 0;
> +                uint8_t next_segment_passes = 0;
> +                int32_t href_passes, pass_bound;
> +                uint32_t tmp_length = 0;
> +
> +                if ((newpasses = getnpasses(s)) <= 0)
> +                    return newpasses;
> +                if (cblk->npasses + newpasses >= JPEG2000_MAX_PASSES) {
> +                    avpriv_request_sample(s->avctx, "Too many passes");
> +                    return AVERROR_PATCHWELCOME;
> +                }
> +                if ((llen = getlblockinc(s)) < 0)
> +                    return llen;
> +                if (cblk->lblock + llen + av_log2(newpasses) > 16) {
> +                    avpriv_request_sample(s->avctx,
> +                                          "Block with length beyond 16 bits");
> +                    return AVERROR_PATCHWELCOME;
> +                }
> +                cblk->nb_lengthinc = 0;
> +                cblk->nb_terminationsinc = 0;
> +                av_free(cblk->lengthinc);
> +                cblk->lengthinc = av_calloc(newpasses, sizeof(*cblk->lengthinc));
> +                if (!cblk->lengthinc)
> +                    return AVERROR(ENOMEM);
> +                tmp = av_realloc_array(cblk->data_start, cblk->nb_terminations + newpasses + 1,
> +                                       sizeof(*cblk->data_start));
> +                if (!tmp)
> +                    return AVERROR(ENOMEM);
> +                cblk->data_start = tmp;
> +                cblk->lblock += llen;
> +
> +                if (cblk->ht_plhd) {
> +                    href_passes = (cblk->npasses + newpasses - 1) % 3;
> +                    segment_passes = newpasses - href_passes;
> +                    pass_bound = 2;
> +                    bits_to_read = cblk->lblock;
> +                    if (segment_passes < 1) {
> +                        // No possible HT Cleanup pass here; may have placeholder passes
> +                        // or an original J2K block bit-stream (in MIXED mode).
> +                        segment_passes = newpasses;
> +                        while (pass_bound <= segment_passes) {
> +                            bits_to_read++;
> +                            pass_bound += pass_bound;
> +                        }
> +                        segment_bytes = get_bits(s, bits_to_read);
> +                        if (segment_bytes) {
> +                            if (cblk->modes & HT_MIXED) {
> +                                cblk->ht_plhd = HT_PLHD_OFF;
> +                                cblk->modes &= (uint8_t) (~(JPEG2000_CTSY_HTJ2K_F));
> +                            }
> +                            else {
> +                                av_log(s->avctx, AV_LOG_WARNING, "Length information for a HT-codeblock is invalid\n");
> +                            }
> +                        }
> +                    } else {
> +                        while (pass_bound <= segment_passes) {
> +                            bits_to_read++;
> +                            pass_bound += pass_bound;
> +                        }
> +                        segment_bytes = get_bits(s, bits_to_read);
> +                        if (segment_bytes) {
> +                            // No more placeholder passes
> +                            if (!(cblk->modes & HT_MIXED)) {
> +                                // Must be the first HT Cleanup pass
> +                                if (segment_bytes < 2)
> +                                    av_log(s->avctx, AV_LOG_WARNING, "Length information for a HT-codeblock is invalid\n");
> +                                next_segment_passes = 2;
> +                                cblk->ht_plhd = HT_PLHD_OFF;
> +                                // Write length information for HT CleanUp segment
> +                                cblk->pass_lengths[0] = segment_bytes;
> +                            } else if (cblk->lblock > 3 && segment_bytes > 1
> +                                       && (segment_bytes >> (bits_to_read - 1)) == 0) {
> +                                // Must be the first HT Cleanup pass, since length MSB is 0
> +                                next_segment_passes = 2;
> +                                cblk->ht_plhd = HT_PLHD_OFF;
> +                                // Write length information for HT CleanUp segment
> +                                cblk->pass_lengths[0] = segment_bytes;
> +                            } else {
> +                                // Must have an original (non-HT) block coding pass
> +                                cblk->modes &= (uint8_t) (~(JPEG2000_CTSY_HTJ2K_F));
> +                                cblk->ht_plhd = HT_PLHD_OFF;
> +                                segment_passes = newpasses;
> +                                while (pass_bound <= segment_passes) {
> +                                    bits_to_read++;
> +                                    pass_bound += pass_bound;
> +                                    segment_bytes <<= 1;
> +                                    segment_bytes += get_bits(s, 1);
> +                                }
> +                            }
> +                        } else {
> +                            // Probably parsing placeholder passes, but we need to read an
> +                            // extra length bit to verify this, since prior to the first
> +                            // HT Cleanup pass, the number of length bits read for a
> +                            // contributing code-block is dependent on the number of passes
> +                            // being included, as if it were a non-HT code-block.
> +                            segment_passes = newpasses;
> +                            if (pass_bound <= segment_passes) {
> +                                while (1) {
> +                                    bits_to_read++;
> +                                    pass_bound += pass_bound;
> +                                    segment_bytes <<= 1;
> +                                    segment_bytes += get_bits(s, 1);
> +                                    if (pass_bound > segment_passes)
> +                                        break;
> +                                }
> +                                if (segment_bytes) {
> +                                    if (cblk->modes & HT_MIXED) {
> +                                        cblk->modes &= (uint8_t) (~(JPEG2000_CTSY_HTJ2K_F));
> +                                        cblk->ht_plhd = HT_PLHD_OFF;
> +                                    } else {
> +                                        av_log(s->avctx, AV_LOG_WARNING, "Length information for a HT-codeblock is invalid\n");
> +                                    }
> +                                }
> +                            }
> +                        }
>                      }
> +                } else if (cblk->modes & JPEG2000_CTSY_HTJ2K_F) {
> +                    // Quality layer commences with a non-initial HT coding pass
> +                    if(bits_to_read != 0)
> +                        av_log(s->avctx, AV_LOG_WARNING, "Length information for a HT-codeblock is invalid\n");
> +                    segment_passes = cblk->npasses % 3;
> +                    if (segment_passes == 0) {
> +                        // newpasses is a HT Cleanup pass; next segment has refinement passes
> +                        segment_passes = 1;
> +                        next_segment_passes = 2;
> +                        if (segment_bytes == 1)
> +                            av_log(s->avctx, AV_LOG_WARNING, "Length information for a HT-codeblock is invalid\n");
> +                    } else {
> +                        // newpasses = 1 means npasses is HT SigProp; 2 means newpasses is
> +                        // HT MagRef pass
> +                        segment_passes = newpasses > 1 ? 3 - segment_passes : 1;
> +                        next_segment_passes = 1;
> +                        bits_to_read = av_log2(segment_passes);
> +                    }
> +                    bits_to_read = (uint8_t) (bits_to_read + cblk->lblock);
> +                    segment_bytes = get_bits(s, bits_to_read);
> +                    // Write length information for HT Refinment segment
> +                    cblk->pass_lengths[1] += segment_bytes;
> +                } else if (!(cblk->modes & (JPEG2000_CBLK_TERMALL | JPEG2000_CBLK_BYPASS))) {
> +                    // Common case for non-HT code-blocks; we have only one segment
> +                    bits_to_read = (uint8_t) cblk->lblock + av_log2((uint8_t) newpasses);
> +                    segment_bytes = get_bits(s, bits_to_read);
> +                    segment_passes = newpasses;
> +                } else if (cblk->modes & JPEG2000_CBLK_TERMALL) {
> +                    // RESTART MODE
> +                    bits_to_read = cblk->lblock;
> +                    segment_bytes = get_bits(s, bits_to_read);
> +                    segment_passes = 1;
> +                    next_segment_passes = 1;
> +                    cblk->nb_terminationsinc++;
> +                } else {
> +                    // BYPASS MODE
> +                    bypass_term_threshold = 10;
> +                    if(bits_to_read != 0)
> +                        av_log(s->avctx, AV_LOG_WARNING, "Length information for a codeblock is invalid\n");
> +                    if (cblk->npasses < bypass_term_threshold) {
> +                        // May have from 1 to 10 uninterrupted passes before 1st RAW SigProp
> +                        segment_passes = bypass_term_threshold - cblk->npasses;
> +                        if (segment_passes > newpasses)
> +                            segment_passes = newpasses;
> +                        while ((2 << bits_to_read) <= segment_passes)
> +                            bits_to_read++;
> +                        next_segment_passes = 2;
> +                    } else if ((cblk->npasses - bypass_term_threshold) % 3 < 2) {
> +                        // 0 means newpasses is a RAW SigProp; 1 means newpasses is a RAW MagRef pass
> +                        segment_passes = newpasses > 1 ? 2 - (cblk->npasses - bypass_term_threshold) % 3 : 1;
> +                        bits_to_read = av_log2(segment_passes);
> +                        next_segment_passes = 1;
> +                    } else {
> +                        // newpasses is an isolated Cleanup pass that precedes a RAW SigProp pass
> +                        segment_passes = 1;
> +                        next_segment_passes = 2;
> +                    }
> +                    bits_to_read = (uint8_t) (bits_to_read + cblk->lblock);
> +                    segment_bytes = get_bits(s, bits_to_read);
>                  }
> -
> -                if (newpasses > 1 && (codsty->cblk_style & JPEG2000_CTSY_HTJ2K_F)) {
> -                    // Retrieve pass lengths for each pass
> -                    int href_passes =  (cblk->npasses + newpasses - 1) % 3;
> -                    int eb = av_log2(newpasses - href_passes);
> -                    int extra_bit = newpasses > 2 ? 1 : 0;
> -                    if ((ret = get_bits(s, llen + eb + 3)) < 0)
> -                        return ret;
> -                    cblk->pass_lengths[0] = ret;
> -                    if ((ret = get_bits(s, llen + 3 + extra_bit)) < 0)
> -                        return ret;
> -                    cblk->pass_lengths[1] = ret;
> -                    ret = cblk->pass_lengths[0] + cblk->pass_lengths[1];
> +                // Update cblk->npasses and write length information
> +                cblk->npasses = (uint8_t) (cblk->npasses + segment_passes);
> +                cblk->lengthinc[cblk->nb_lengthinc++] = segment_bytes;
> +
> +                if ((cblk->modes & JPEG2000_CTSY_HTJ2K_F) && cblk->ht_plhd == HT_PLHD_OFF) {
> +                    newpasses -= (uint8_t) segment_passes;
> +                    while (newpasses > 0) {
> +                        segment_passes = newpasses > 1 ? next_segment_passes : 1;
> +                        next_segment_passes = (uint8_t) (3 - next_segment_passes);
> +                        bits_to_read = (uint8_t) (cblk->lblock + av_log2(segment_passes));
> +                        segment_bytes = get_bits(s, bits_to_read);
> +                        newpasses -= (uint8_t) (segment_passes);
> +                        // This is a FAST Refinement pass
> +                        // Write length information for HT Refinement segment
> +                        cblk->pass_lengths[1] += segment_bytes;
> +                        // Update cblk->npasses and write length information
> +                        cblk->npasses = (uint8_t) (cblk->npasses + segment_passes);
> +                        cblk->lengthinc[cblk->nb_lengthinc++] = segment_bytes;
> +                    }
>                  } else {
> -                    if ((ret = get_bits(s, av_log2(newpasses1) + cblk->lblock)) < 0)
> -                        return ret;
> -                    cblk->pass_lengths[0] = ret;
> +                    newpasses -= (uint8_t) (segment_passes);
> +                    while (newpasses > 0) {
> +                        if (bypass_term_threshold != 0) {
> +                            segment_passes = newpasses > 1 ? next_segment_passes : 1;
> +                            next_segment_passes = (uint8_t) (3 - next_segment_passes);
> +                            bits_to_read = (uint8_t) (cblk->lblock + av_log2(segment_passes));
> +                        } else {
> +                            if ((cblk->modes & JPEG2000_CBLK_TERMALL) == 0)
> +                                av_log(s->avctx, AV_LOG_WARNING, "Corrupted packet header is found.\n");
> +                            segment_passes = 1;
> +                            bits_to_read = cblk->lblock;
> +                        }
> +                        segment_bytes = get_bits(s, bits_to_read);
> +                        newpasses -= (uint8_t) (segment_passes);
> +
> +                        // Update cblk->npasses and write length information
> +                        cblk->npasses = (uint8_t) (cblk->npasses + segment_passes);
> +                        cblk->lengthinc[cblk->nb_lengthinc++] = segment_bytes;
> +                        cblk->nb_terminationsinc++;
> +                    }
>                  }
> -                if (ret > cblk->data_allocated) {
> -                    size_t new_size = FFMAX(2*cblk->data_allocated, ret);
> +
> +                for (int i = 0; i < cblk->nb_lengthinc; ++i)
> +                    tmp_length = (tmp_length < cblk->lengthinc[i]) ? cblk->lengthinc[i] : tmp_length;
> +
> +                if (tmp_length > cblk->data_allocated) {
> +                    size_t new_size = FFMAX(2 * cblk->data_allocated, tmp_length);
>                      void *new = av_realloc(cblk->data, new_size);
>                      if (new) {
>                          cblk->data = new;
>                          cblk->data_allocated = new_size;
>                      }
>                  }
> -                if (ret > cblk->data_allocated) {
> +                if (tmp_length > cblk->data_allocated) {
>                      avpriv_request_sample(s->avctx,
>                                          "Block with lengthinc greater than %"SIZE_SPECIFIER"",
>                                          cblk->data_allocated);
>                      return AVERROR_PATCHWELCOME;
>                  }
> -                cblk->lengthinc[cblk->nb_lengthinc++] = ret;
> -                cblk->npasses  += newpasses1;
> -                newpasses -= newpasses1;
> -            } while(newpasses);
> +            } else {
> +                // This codeblock has no contribution to the current packet
> +                continue;
> +            }
>          }
>      }
>      jpeg2000_flush(s);
> @@ -1695,7 +1962,7 @@ static int decode_cblk(const Jpeg2000DecoderContext *s, Jpeg2000CodingStyle *cod
>                         Jpeg2000T1Context *t1, Jpeg2000Cblk *cblk,
>                         int width, int height, int bandpos, uint8_t roi_shift)
>  {
> -    int passno = cblk->npasses, pass_t = 2, bpno = cblk->nonzerobits - 1 + roi_shift;
> +    int passno = cblk->npasses, pass_t = 2, bpno = cblk->nonzerobits - 1;
>      int pass_cnt = 0;
>      int vert_causal_ctx_csty_symbol = codsty->cblk_style & JPEG2000_CBLK_VSC;
>      int term_cnt = 0;
> @@ -1909,7 +2176,7 @@ static inline int tile_codeblocks(const Jpeg2000DecoderContext *s, Jpeg2000Tile
>                  Jpeg2000Band *band = rlevel->band + bandno;
>                  int cblkno = 0, bandpos;
>                  /* See Rec. ITU-T T.800, Equation E-2 */
> -                int magp = quantsty->expn[subbandno] + quantsty->nguardbits - 1;
> +                int M_b = quantsty->expn[subbandno] + quantsty->nguardbits - 1;
>
>                  bandpos = bandno + (reslevelno > 0);
>
> @@ -1917,8 +2184,8 @@ static inline int tile_codeblocks(const Jpeg2000DecoderContext *s, Jpeg2000Tile
>                      band->coord[1][0] == band->coord[1][1])
>                      continue;
>
> -                if ((codsty->cblk_style & JPEG2000_CTSY_HTJ2K_F) && magp >= 31) {
> -                    avpriv_request_sample(s->avctx, "JPEG2000_CTSY_HTJ2K_F and magp >= 31");
> +                if ((codsty->cblk_style & JPEG2000_CTSY_HTJ2K_F) && M_b >= 31) {
> +                    avpriv_request_sample(s->avctx, "JPEG2000_CTSY_HTJ2K_F and M_b >= 31");
>                      return AVERROR_PATCHWELCOME;
>                  }
>
> @@ -1935,11 +2202,11 @@ static inline int tile_codeblocks(const Jpeg2000DecoderContext *s, Jpeg2000Tile
>
>                          Jpeg2000Cblk *cblk = prec->cblk + cblkno;
>
> -                        if (codsty->cblk_style & JPEG2000_CTSY_HTJ2K_F)
> +                        if (cblk->modes & JPEG2000_CTSY_HTJ2K_F)
>                              ret = ff_jpeg2000_decode_htj2k(s, codsty, &t1, cblk,
>                                                             cblk->coord[0][1] - cblk->coord[0][0],
>                                                             cblk->coord[1][1] - cblk->coord[1][0],
> -                                                           magp, comp->roi_shift);
> +                                                           M_b, comp->roi_shift);
>                          else
>                              ret = decode_cblk(s, codsty, &t1, cblk,
>                                                cblk->coord[0][1] - cblk->coord[0][0],
> @@ -2178,22 +2445,42 @@ static int jpeg2000_read_main_headers(Jpeg2000DecoderContext *s)
>              if (!s->tile)
>                  s->numXtiles = s->numYtiles = 0;
>              break;
> +        case JPEG2000_CAP:
> +            if (!s->ncomponents) {
> +                av_log(s->avctx, AV_LOG_WARNING, "CAP marker segment shall come after SIZ\n");
> +            }
> +            ret = get_cap(s, codsty);
> +            break;
>          case JPEG2000_COC:
> +            if (s->in_tile_headers == 1 && s->isHT && (!s->Ccap15_b11))
> +                av_log(s->avctx, AV_LOG_WARNING, "COC marker is found in HOMOGENEOUS HT set\n");
>              ret = get_coc(s, codsty, properties);
>              break;
>          case JPEG2000_COD:
> +            if (s->in_tile_headers == 1 && s->isHT && (!s->Ccap15_b11))
> +                av_log(s->avctx, AV_LOG_WARNING, "COD marker is found in HOMOGENEOUS HT set\n");
>              ret = get_cod(s, codsty, properties);
>              break;
>          case JPEG2000_RGN:
> +            if (s->in_tile_headers == 1 && s->isHT && (!s->Ccap15_b11))
> +                av_log(s->avctx, AV_LOG_WARNING, "RGB marker is found in HOMOGENEOUS HT set\n");
>              ret = get_rgn(s, len);
> +            if ((!s->Ccap15_b12) && s->isHT)
> +                av_log(s->avctx, AV_LOG_WARNING, "RGN marker is found in RGNFREE HT set\n");
>              break;
>          case JPEG2000_QCC:
> +            if (s->in_tile_headers == 1 && s->isHT && (!s->Ccap15_b11))
> +                av_log(s->avctx, AV_LOG_WARNING, "QCC marker is found in HOMOGENEOUS HT set\n");
>              ret = get_qcc(s, len, qntsty, properties);
>              break;
>          case JPEG2000_QCD:
> +            if (s->in_tile_headers == 1 && s->isHT && (!s->Ccap15_b11))
> +                av_log(s->avctx, AV_LOG_WARNING, "QCD marker is found in HOMOGENEOUS HT set\n");
>              ret = get_qcd(s, len, qntsty, properties);
>              break;
>          case JPEG2000_POC:
> +            if (s->in_tile_headers == 1 && s->isHT && (!s->Ccap15_b11))
> +                av_log(s->avctx, AV_LOG_WARNING, "POC marker is found in HOMOGENEOUS HT set\n");
>              ret = get_poc(s, len, poc);
>              break;
>          case JPEG2000_SOT:
> @@ -2243,9 +2530,14 @@ static int jpeg2000_read_main_headers(Jpeg2000DecoderContext *s)
>                         "Cannot have both PPT and PPM marker.\n");
>                  return AVERROR_INVALIDDATA;
>              }
> -
> +            if ((!s->Ccap15_b11) && s->isHT)
> +                av_log(s->avctx, AV_LOG_WARNING, "PPT marker is found in HOMOGENEOUS HT set\n");
>              ret = get_ppt(s, len);
>              break;
> +        case JPEG2000_CPF:
> +            // Corresponding profile marker
> +            ret = read_cpf(s, len);
> +            break;
>          default:
>              av_log(s->avctx, AV_LOG_ERROR,
>                     "unsupported marker 0x%.4"PRIX16" at pos 0x%X\n",
> diff --git a/libavcodec/jpeg2000dec.h b/libavcodec/jpeg2000dec.h
> index d0ca6e7a79..326a572722 100644
> --- a/libavcodec/jpeg2000dec.h
> +++ b/libavcodec/jpeg2000dec.h
> @@ -112,6 +112,13 @@ typedef struct Jpeg2000DecoderContext {
>      Jpeg2000Tile    *tile;
>      Jpeg2000DSPContext dsp;
>
> +    uint8_t         isHT; // HTJ2K?
> +    uint8_t         Ccap15_b14_15; // HTONLY(= 0) or HTDECLARED(= 1) or MIXED(= 3) ?
> +    uint8_t         Ccap15_b12; // RGNFREE(= 0) or RGN(= 1)?
> +    uint8_t         Ccap15_b11; // HOMOGENEOUS(= 0) or HETEROGENEOUS(= 1) ?
> +    uint8_t         Ccap15_b05; // HTREV(= 0) or HTIRV(= 1) ?
> +    uint8_t         HT_MAGB; // MAGB value
> +
>      /*options parameters*/
>      int             reduction_factor;
>  } Jpeg2000DecoderContext;
> diff --git a/libavcodec/jpeg2000htdec.c b/libavcodec/jpeg2000htdec.c
> index eba0936089..beb4a386b0 100644
> --- a/libavcodec/jpeg2000htdec.c
> +++ b/libavcodec/jpeg2000htdec.c
> @@ -122,7 +122,7 @@ static void jpeg2000_init_mel(StateVars *s, uint32_t Pcup)
>
>  static void jpeg2000_init_mag_ref(StateVars *s, uint32_t Lref)
>  {
> -    s->pos       = Lref - 2;
> +    s->pos       = Lref - 1;
>      s->bits      = 0;
>      s->last      = 0xFF;
>      s->tmp       = 0;
> @@ -145,9 +145,10 @@ static void jpeg2000_init_mel_decoder(MelDecoderState *mel_state)
>  static int jpeg2000_bitbuf_refill_backwards(StateVars *buffer, const uint8_t *array)
>  {
>      uint64_t tmp = 0;
> -    int32_t position = buffer->pos - 4;
>      uint32_t new_bits = 32;
>
> +    buffer->last = array[buffer->pos + 1];
> +
>      if (buffer->bits_left >= 32)
>          return 0; // enough data, no need to pull in more bits
>
> @@ -157,9 +158,24 @@ static int jpeg2000_bitbuf_refill_backwards(StateVars *buffer, const uint8_t *ar
>       *  the bottom most bits.
>       */
>
> -    for(int i = FFMAX(0, position + 1); i <= buffer->pos + 1; i++)
> -        tmp = 256*tmp + array[i];
> -
> +    if (buffer->pos >= 3) {  // Common case; we have at least 4 bytes available
> +         tmp = array[buffer->pos - 3];
> +         tmp = (tmp << 8) | array[buffer->pos - 2];
> +         tmp = (tmp << 8) | array[buffer->pos - 1];
> +         tmp = (tmp << 8) | array[buffer->pos];
> +         tmp = (tmp << 8) | buffer->last;  // For stuffing bit detection
> +         buffer->pos -= 4;
> +    } else {
> +        if (buffer->pos >= 2)
> +            tmp = array[buffer->pos - 2];
> +        if (buffer->pos >= 1)
> +            tmp = (tmp << 8) | array[buffer->pos - 1];
> +        if (buffer->pos >= 0)
> +            tmp = (tmp << 8) | array[buffer->pos];
> +        buffer->pos = 0;
> +        tmp = (tmp << 8) | buffer->last;  // For stuffing bit detection
> +    }
> +    // Now remove any stuffing bits, shifting things down as we go
>      if ((tmp & 0x7FFF000000) > 0x7F8F000000) {
>          tmp &= 0x7FFFFFFFFF;
>          new_bits--;
> @@ -176,13 +192,11 @@ static int jpeg2000_bitbuf_refill_backwards(StateVars *buffer, const uint8_t *ar
>          tmp = (tmp & 0x0000007FFF) + ((tmp & 0xFFFFFF0000) >> 1);
>          new_bits--;
>      }
> -
> -    tmp >>= 8; // Remove temporary byte loaded
> +    tmp >>= 8;  // Shifts away the extra byte we imported
>
>      /* 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;
>  }
>
> @@ -406,6 +420,7 @@ static void recover_mag_sgn(StateVars *mag_sgn, uint8_t pos, uint16_t q, int32_t
>              E[n] = 32 - ff_clz(v[pos][i] | 1);
>              mu_n[n] = (v[pos][i] >> 1) + 1;
>              mu_n[n] <<= pLSB;
> +            mu_n[n] |= (1 << (pLSB - 1)); // Add 0.5 (reconstruction parameter = 1/2)
>              mu_n[n] |= ((uint32_t) (v[pos][i] & 1)) << 31; // sign bit.
>          }
>      }
> @@ -414,7 +429,7 @@ static void recover_mag_sgn(StateVars *mag_sgn, uint8_t pos, uint16_t q, int32_t
>  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);
> +    int pos = FFMIN(stream->pos, length - 1);
>      if (stream->bits == 0) {
>          stream->bits = (stream->tmp == 0xFF) ? 7 : 8;
>          stream->pos += cond;
> @@ -426,14 +441,22 @@ static int jpeg2000_import_bit(StateVars *stream, const uint8_t *array, uint32_t
>
>  static int jpeg2000_peek_bit(StateVars *stream, const uint8_t *array, uint32_t length)
>  {
> +    uint8_t bit;
> +
>      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;
> +        stream->bits = (stream->last == 0xFF) ? 7 : 8;
> +        if (stream->pos < length) {
> +            stream->tmp = array[stream->pos];
> +            stream->pos++;
> +        } else {
> +            stream->tmp = 0;
> +        }
> +        stream->last = stream->tmp;
>      }
> -    return (stream->tmp >> stream->bits) & 1;
> +    bit = stream->tmp & 1;
> +    stream->tmp >>= 1;
> +    stream->bits--;
> +    return  bit;
>  }
>
>  static int jpeg2000_decode_mel_sym(MelDecoderState *mel_state,
> @@ -994,66 +1017,63 @@ 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 stride)
>  {
> -    int local_mbr = 0;
> -
> -    local_mbr |= jpeg2000_get_state(i - 1, j - 1, stride, HT_SHIFT_SIGMA, block_states);
> -    local_mbr |= jpeg2000_get_state(i - 1, j + 0, stride, HT_SHIFT_SIGMA, block_states);
> -    local_mbr |= jpeg2000_get_state(i - 1, j + 1, stride, HT_SHIFT_SIGMA, block_states);
> -
> -    local_mbr |= jpeg2000_get_state(i + 0, j - 1, stride, HT_SHIFT_SIGMA, block_states);
> -    local_mbr |= jpeg2000_get_state(i + 0, j + 1, stride, HT_SHIFT_SIGMA, block_states);
> -
> -    local_mbr |= jpeg2000_get_state(i + 1, j - 1, stride, HT_SHIFT_SIGMA, block_states) * causal_cond;
> -    local_mbr |= jpeg2000_get_state(i + 1, j + 0, stride, HT_SHIFT_SIGMA, block_states) * causal_cond;
> -    local_mbr |= jpeg2000_get_state(i + 1, j + 1, stride, HT_SHIFT_SIGMA, block_states) * causal_cond;
> -
> -    local_mbr |= jpeg2000_get_state(i - 1, j - 1, stride, HT_SHIFT_REF, block_states) *
> -                 jpeg2000_get_state(i - 1, j - 1, stride, HT_SHIFT_SCAN, block_states);
> -    local_mbr |= jpeg2000_get_state(i - 1, j + 0, stride, HT_SHIFT_REF, block_states) *
> -                 jpeg2000_get_state(i - 1, j - 1, stride, HT_SHIFT_SCAN, block_states);
> -    local_mbr |= jpeg2000_get_state(i - 1, j + 1, stride, HT_SHIFT_REF, block_states) *
> -                 jpeg2000_get_state(i - 1, j + 1, stride, HT_SHIFT_SCAN, block_states);
> -
> -    local_mbr |= jpeg2000_get_state(i + 0, j - 1, stride, HT_SHIFT_REF, block_states) *
> -                 jpeg2000_get_state(i + 0, j - 1, stride, HT_SHIFT_SCAN, block_states);
> -    local_mbr |= jpeg2000_get_state(i + 0, j + 1, stride, HT_SHIFT_REF, block_states) *
> -                 jpeg2000_get_state(i + 0, j + 1, stride, HT_SHIFT_SCAN, block_states);
> -
> -    local_mbr |= jpeg2000_get_state(i + 1, j - 1, stride, HT_SHIFT_REF, block_states) *
> -                 jpeg2000_get_state(i + 1, j - 1, stride, HT_SHIFT_SCAN, block_states) * causal_cond;
> -    local_mbr |= jpeg2000_get_state(i + 1, j + 0, stride, HT_SHIFT_REF, block_states) *
> -                 jpeg2000_get_state(i + 1, j + 0, stride, HT_SHIFT_SCAN, block_states) * causal_cond;
> -    local_mbr |= jpeg2000_get_state(i + 1, j + 1, stride, HT_SHIFT_REF, block_states) *
> -                 jpeg2000_get_state(i + 1, j + 1, stride, HT_SHIFT_SCAN, block_states) * causal_cond;
> -
> -    *mbr |= local_mbr;
> +    uint8_t *state_p0 = block_states + i * stride + j;
> +    uint8_t *state_p1 = block_states + (i + 1) * stride + j;
> +    uint8_t *state_p2 = block_states + (i + 2) * stride + j;
> +
> +    uint8_t mbr0 = state_p0[0] | state_p0[1] | state_p0[2];
> +    uint8_t mbr1 = state_p1[0] | state_p1[2];
> +    uint8_t mbr2 = state_p2[0] | state_p2[1] | state_p2[2];
> +    *mbr  = mbr0 | mbr1 | (mbr2 & causal_cond);
> +    *mbr |= (mbr0 >> HT_SHIFT_REF) & (mbr0 >> HT_SHIFT_SCAN);
> +    *mbr |= (mbr1 >> HT_SHIFT_REF) & (mbr1 >> HT_SHIFT_SCAN);
> +    *mbr |= (mbr2 >> HT_SHIFT_REF) & (mbr2 >> HT_SHIFT_SCAN) & causal_cond;
> +    *mbr &= 1;
>  }
>
>  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)
> +                                           uint8_t *magref_segment, uint32_t magref_length,
> +                                           uint8_t is_causal)
>  {
>      for (int j = j_s; j < j_s + width; j++) {
>          uint32_t  mbr_info = 0;
>          for (int i = i_s; i < i_s + height; i++) {
> -            int modify_state, cond;
> +            int modify_state;
>              uint8_t bit;
> -            uint8_t causal_cond = i != (i_s + height - 1);
> +            uint8_t causal_cond = (is_causal == 0) || (i != (i_s + height - 1));
>              int32_t *sp = &sample_buf[j + (i * (stride))];
>              uint8_t mbr = 0;
>
> -            if (jpeg2000_get_state(i, j, stride - 2, HT_SHIFT_SIGMA, block_states) == 0)
> +            if (jpeg2000_get_state(i, j, stride, HT_SHIFT_SIGMA, block_states) == 0)
>                  jpeg2000_calc_mbr(&mbr, i, j, mbr_info & 0x1EF, causal_cond, block_states, stride);
>              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;
> +
> +            modify_state = block_states[(i + 1) * stride + (j + 1)];
> +            modify_state |= 1 << HT_SHIFT_SCAN;
> +            if (mbr != 0) {
> +                modify_state |= 1 << HT_SHIFT_REF_IND;
> +                bit = jpeg2000_peek_bit(sig_prop, magref_segment, magref_length);
> +                modify_state |= bit << HT_SHIFT_REF;
> +                *sp |= bit << pLSB;
> +                *sp |= bit << (pLSB - 1); // Add 0.5 (reconstruction parameter = 1/2)
> +            }
>              jpeg2000_modify_state(i, j, stride, modify_state, block_states);
>          }
>      }
> +    // decode sign
> +    for (int j = j_s; j < j_s + width; j++) {
> +        for (int i = i_s; i < i_s + height; i++) {
> +            uint8_t bit;
> +            int32_t *sp = &sample_buf[j + (i * (stride))];
> +            uint8_t *state_p = block_states + (i + 1) * stride + (j + 1);
> +            if ((state_p[0] >> HT_SHIFT_REF) & 1) {
> +                bit = jpeg2000_peek_bit(sig_prop, magref_segment, magref_length);
> +                *sp |= (int32_t)bit << 31;
> +            }
> +        }
> +    }
>  }
>
>  /**
> @@ -1074,6 +1094,7 @@ static void jpeg2000_decode_sigprop_segment(Jpeg2000Cblk *cblk, uint16_t width,
>
>      int last_width;
>      uint16_t i = 0, j = 0;
> +    uint8_t is_causal = cblk->modes & JPEG2000_CBLK_VSC;
>
>      jpeg2000_init_zero(&sp_dec);
>
> @@ -1082,14 +1103,14 @@ static void jpeg2000_decode_sigprop_segment(Jpeg2000Cblk *cblk, uint16_t width,
>          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);
> +                                           magref_length, is_causal);
>              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);
> +                                           magref_length, is_causal);
>          i += 4;
>      }
>
> @@ -1099,20 +1120,20 @@ static void jpeg2000_decode_sigprop_segment(Jpeg2000Cblk *cblk, uint16_t width,
>      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);
> +                                       magref_length, is_causal);
>          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);
> +                                       magref_length, is_causal);
>  }
>
>  /**
>   * See procedure decodeSigPropMag at Rec. ITU-T T.814, 7.5.
>  */
> -static int
> +static void
>  jpeg2000_decode_magref_segment( uint16_t width, uint16_t block_height, const int stride,
>                                  uint8_t *magref_segment,uint32_t magref_length,
>                                  uint8_t pLSB, int32_t *sample_buf, uint8_t *block_states)
> @@ -1123,7 +1144,8 @@ jpeg2000_decode_magref_segment( uint16_t width, uint16_t block_height, const int
>      uint16_t height             = 4;
>      uint16_t i_start            = 0;
>      int32_t *sp;
> -
> +    int32_t bit;
> +    int32_t tmp;
>      jpeg2000_init_mag_ref(&mag_ref, magref_length);
>
>      for (int n1 = 0; n1 < num_v_stripe; n1++) {
> @@ -1134,9 +1156,13 @@ jpeg2000_decode_magref_segment( uint16_t width, uint16_t block_height, const int
>                   *  Rec. ITU-T T.814, Figure 7.
>                   */
>                  sp = &sample_buf[j + i * stride];
> -                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;
> +                if (jpeg2000_get_state(i, j, stride, HT_SHIFT_SIGMA, block_states) != 0) {
> +                    jpeg2000_modify_state(i, j, stride, 1 << HT_SHIFT_REF_IND, block_states);
> +                    bit = jpeg2000_import_magref_bit(&mag_ref, magref_segment, magref_length);
> +                    tmp = 0xFFFFFFFE | (uint32_t)bit;
> +                    tmp <<= pLSB;
> +                    sp[0] &= tmp;
> +                    sp[0] |= 1 << (pLSB - 1); // Add 0.5 (reconstruction parameter = 1/2)
>                  }
>              }
>          }
> @@ -1146,21 +1172,24 @@ jpeg2000_decode_magref_segment( uint16_t width, uint16_t block_height, const int
>      for (int j = 0; j < width; j++) {
>          for (int i = i_start; i < i_start + height; i++) {
>              sp = &sample_buf[j + i * stride];
> -            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;
> +            if (jpeg2000_get_state(i, j, stride, HT_SHIFT_SIGMA, block_states) != 0) {
> +                jpeg2000_modify_state(i, j, stride, 1 << HT_SHIFT_REF_IND, block_states);
> +                bit = jpeg2000_import_magref_bit(&mag_ref, magref_segment, magref_length);
> +                tmp = 0xFFFFFFFE | (uint32_t)bit;
> +                tmp <<= pLSB;
> +                sp[0] &= tmp;
> +                sp[0] |= 1 << (pLSB - 1); // Add 0.5 (reconstruction parameter = 1/2)
>              }
>          }
>      }
> -    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)
> +                         int width, int height, int M_b, uint8_t roi_shift)
>  {
> -    uint8_t p0 = 0;             // Number of placeholder passes
> +    uint8_t p0 = 0;             // 3 * p0 = 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
> @@ -1174,7 +1203,7 @@ ff_jpeg2000_decode_htj2k(const Jpeg2000DecoderContext *s, Jpeg2000CodingStyle *c
>
>      int z_blk;                  // Number of ht coding pass
>
> -    uint8_t empty_passes;
> +    uint8_t num_plhd_passes;    // Number of placeholder passes
>
>      StateVars mag_sgn;          // Magnitude and Sign
>      StateVars mel;              // Adaptive run-length coding
> @@ -1190,8 +1219,8 @@ ff_jpeg2000_decode_htj2k(const Jpeg2000DecoderContext *s, Jpeg2000CodingStyle *c
>      uint8_t *block_states = NULL;
>
>      int32_t n, val;             // Post-processing
> -
> -    int32_t M_b = magp;
> +    const uint32_t mask  = UINT32_MAX >> (M_b + 1); // bit mask for ROI detection
> +    uint8_t num_rempass;
>
>      const int quad_buf_width = width + 4;
>      const int quad_buf_height = height + 4;
> @@ -1201,22 +1230,17 @@ ff_jpeg2000_decode_htj2k(const Jpeg2000DecoderContext *s, Jpeg2000CodingStyle *c
>      av_assert0(width * height <= 4096);
>      av_assert0(width * height > 0);
>
> -    if (roi_shift)
> -        avpriv_report_missing_feature(s->avctx, "ROI shift");
> -
>      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;
> +    num_rempass = cblk->npasses % 3;  // Number of remainder passes
> +    num_plhd_passes = num_rempass ? cblk->npasses - num_rempass : cblk->npasses - 3;
> +    av_assert0(num_plhd_passes % 3 == 0);
> +    p0 = num_plhd_passes / 3;
> +    z_blk = cblk->npasses - num_plhd_passes;
>
>      if (z_blk <= 0)
>          return 0; // No passes within this set, continue
> @@ -1231,7 +1255,11 @@ ff_jpeg2000_decode_htj2k(const Jpeg2000DecoderContext *s, Jpeg2000CodingStyle *c
>      }
>      Dcup = cblk->data;
>      Dref  = cblk->data + Lcup; // Dref comes after the refinement segment
> +
> +    cblk->data[cblk->length] = 0xFF; // an extra byte for refinement segment (buffer->last)
> +
>      S_blk = p0 + cblk->zbp;
> +    cblk->zbp = S_blk - 1;
>      pLSB  = 30 - S_blk;
>
>      Scup = (Dcup[Lcup - 1] << 4) + (Dcup[Lcup - 2] & 0x0F);
> @@ -1277,31 +1305,32 @@ ff_jpeg2000_decode_htj2k(const Jpeg2000DecoderContext *s, Jpeg2000CodingStyle *c
>          goto free;
>      }
>
> -    if (cblk->npasses > 1)
> +    if (z_blk > 1)
>          jpeg2000_decode_sigprop_segment(cblk, width, height, quad_buf_width, Dref, Lref,
>                                          pLSB - 1, sample_buf, block_states);
>
> -    if (cblk->npasses > 2) {
> -
> -        if (Lref < 2){
> -            av_log(s->avctx,AV_LOG_ERROR,"Invalid magnitude refinement length\n");
> -            ret = AVERROR_INVALIDDATA;
> -            goto free;
> -        }
> -        if ((ret = jpeg2000_decode_magref_segment(width, height, quad_buf_width, Dref, Lref,
> -                                                  pLSB - 1, sample_buf, block_states)) < 0)
> -            goto free;
> -    }
> +    if (z_blk > 2)
> +        jpeg2000_decode_magref_segment(width, height, quad_buf_width, Dref, Lref,
> +                                       pLSB - 1, sample_buf, block_states);
>
>      pLSB = 31 - M_b;
>
>      /* Reconstruct the sample values */
>      for (int y = 0; y < height; y++) {
>          for (int x = 0; x < width; x++) {
> +            int32_t sign;
> +
>              n = x + (y * t1->stride);
>              val = sample_buf[x + (y * quad_buf_width)];
> +            sign = val & INT32_MIN;
> +            val &= INT32_MAX;
> +            /* ROI shift, if necessary */
> +            if (roi_shift && (((uint32_t)val & ~mask) == 0))
> +                val <<= roi_shift;
>              /* Convert sign-magnitude to two's complement. */
> -            val = val >> 31 ? 0x80000000 - val : val;
> +            if (sign)
> +                val = -val;
> +            /* Shift down to 1 bit upper from decimal point for reconstruction value (= 0.5) */
>              val >>= (pLSB - 1);
>              t1->data[n] = val;
>          }
> diff --git a/libavcodec/jpeg2000htdec.h b/libavcodec/jpeg2000htdec.h
> index 572d095c92..8d6919a0de 100644
> --- a/libavcodec/jpeg2000htdec.h
> +++ b/libavcodec/jpeg2000htdec.h
> @@ -29,6 +29,6 @@
>
>  int ff_jpeg2000_decode_htj2k(const Jpeg2000DecoderContext *s, Jpeg2000CodingStyle *codsty,
>                              Jpeg2000T1Context *t1, Jpeg2000Cblk *cblk, int width,
> -                            int height, int magp, uint8_t roi_shift);
> +                            int height, int M_b, uint8_t roi_shift);
>
>  #endif /* AVCODEC_JPEG2000HTDEC_H */
> --
> 2.34.1
>


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