Commit message: avcodec/jpeg2000dec: prevent out of array accesses in pixel addressing

Fixes Ticket2921

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
CVE: CVE-2013-7024
CWE: CWE-119
Vulnerability description: The jpeg2000_decode_tile function in libavcodec/jpeg2000dec.c in FFmpeg before 2.1 does not consider the component number in certain calculations, which allows remote attackers to cause a denial of service (out-of-bounds array access) or possibly have unspecified other impact via crafted JPEG2000 data.

Project: FFmpeg
File: jpeg2000dec.c

static int decode_cblk(Jpeg2000DecoderContext *s, Jpeg2000CodingStyle *codsty,
                       Jpeg2000T1Context *t1, Jpeg2000Cblk *cblk,
                       int width, int height, int bandpos)
{
    int passno = cblk->npasses, pass_t = 2, bpno = cblk->nonzerobits - 1, y;
    int clnpass_cnt = 0;
    int bpass_csty_symbol           = codsty->cblk_style & JPEG2000_CBLK_BYPASS;
    int vert_causal_ctx_csty_symbol = codsty->cblk_style & JPEG2000_CBLK_VSC;

    av_assert0(width  <= JPEG2000_MAX_CBLKW);
    av_assert0(height <= JPEG2000_MAX_CBLKH);

    for (y = 0; y < height; y++)
        memset(t1->data[y], 0, width * sizeof(**t1->data));

    /* If code-block contains no compressed data: nothing to do. */
    if (!cblk->length)
        return 0;

    for (y = 0; y < height + 2; y++)
        memset(t1->flags[y], 0, (width + 2) * sizeof(**t1->flags));

    cblk->data[cblk->length] = 0xff;
    cblk->data[cblk->length+1] = 0xff;
    ff_mqc_initdec(&t1->mqc, cblk->data);

    while (passno--) {
        switch(pass_t) {
        case 0:
            decode_sigpass(t1, width, height, bpno + 1, bandpos,
                           bpass_csty_symbol && (clnpass_cnt >= 4),
                           vert_causal_ctx_csty_symbol);
            break;
        case 1:
            decode_refpass(t1, width, height, bpno + 1);
            if (bpass_csty_symbol && clnpass_cnt >= 4)
                ff_mqc_initdec(&t1->mqc, cblk->data);
            break;
        case 2:
            decode_clnpass(s, t1, width, height, bpno + 1, bandpos,
                           codsty->cblk_style & JPEG2000_CBLK_SEGSYM,
                           vert_causal_ctx_csty_symbol);
            clnpass_cnt = clnpass_cnt + 1;
            if (bpass_csty_symbol && clnpass_cnt >= 4)
                ff_mqc_initdec(&t1->mqc, cblk->data);
            break;
        }

        pass_t++;
        if (pass_t == 3) {
            bpno--;
            pass_t = 0;
        }
    }
    return 0;
}

Project: FFmpeg
File: jpeg2000dec.c

static void decode_clnpass(Jpeg2000DecoderContext *s, Jpeg2000T1Context *t1,
                           int width, int height, int bpno, int bandno,
                           int seg_symbols, int vert_causal_ctx_csty_symbol)
{
    int mask = 3 << (bpno - 1), y0, x, y, runlen, dec;

    for (y0 = 0; y0 < height; y0 += 4) {
        for (x = 0; x < width; x++) {
            if (y0 + 3 < height &&
                !((t1->flags[y0 + 1][x + 1] & (JPEG2000_T1_SIG_NB | JPEG2000_T1_VIS | JPEG2000_T1_SIG)) ||
                  (t1->flags[y0 + 2][x + 1] & (JPEG2000_T1_SIG_NB | JPEG2000_T1_VIS | JPEG2000_T1_SIG)) ||
                  (t1->flags[y0 + 3][x + 1] & (JPEG2000_T1_SIG_NB | JPEG2000_T1_VIS | JPEG2000_T1_SIG)) ||
                  (t1->flags[y0 + 4][x + 1] & (JPEG2000_T1_SIG_NB | JPEG2000_T1_VIS | JPEG2000_T1_SIG)))) {
                if (!ff_mqc_decode(&t1->mqc, t1->mqc.cx_states + MQC_CX_RL))
                    continue;
                runlen = ff_mqc_decode(&t1->mqc,
                                       t1->mqc.cx_states + MQC_CX_UNI);
                runlen = (runlen << 1) | ff_mqc_decode(&t1->mqc,
                                                       t1->mqc.cx_states +
                                                       MQC_CX_UNI);
                dec = 1;
            } else {
                runlen = 0;
                dec    = 0;
            }

            for (y = y0 + runlen; y < y0 + 4 && y < height; y++) {
                if (!dec) {
                    if (!(t1->flags[y+1][x+1] & (JPEG2000_T1_SIG | JPEG2000_T1_VIS))) {
                        int flags_mask = -1;
                        if (vert_causal_ctx_csty_symbol && y == y0 + 3)
                            flags_mask &= ~(JPEG2000_T1_SIG_S | JPEG2000_T1_SIG_SW | JPEG2000_T1_SIG_SE);
                        dec = ff_mqc_decode(&t1->mqc, t1->mqc.cx_states + ff_jpeg2000_getsigctxno(t1->flags[y+1][x+1] & flags_mask,
                                                                                             bandno));
                    }
                }
                if (dec) {
                    int xorbit;
                    int ctxno = ff_jpeg2000_getsgnctxno(t1->flags[y + 1][x + 1],
                                                        &xorbit);
                    t1->data[y][x] = (ff_mqc_decode(&t1->mqc,
                                                    t1->mqc.cx_states + ctxno) ^
                                      xorbit)
                                     ? -mask : mask;
                    ff_jpeg2000_set_significance(t1, x, y, t1->data[y][x] < 0);
                }
                dec = 0;
                t1->flags[y + 1][x + 1] &= ~JPEG2000_T1_VIS;
            }
        }
    }
    if (seg_symbols) {
        int val;
        val = ff_mqc_decode(&t1->mqc, t1->mqc.cx_states + MQC_CX_UNI);
        val = (val << 1) + ff_mqc_decode(&t1->mqc, t1->mqc.cx_states + MQC_CX_UNI);
        val = (val << 1) + ff_mqc_decode(&t1->mqc, t1->mqc.cx_states + MQC_CX_UNI);
        val = (val << 1) + ff_mqc_decode(&t1->mqc, t1->mqc.cx_states + MQC_CX_UNI);
        if (val != 0xa)
            av_log(s->avctx, AV_LOG_ERROR,
                   "Segmentation symbol value incorrect\n");
    }
}

Project: FFmpeg
File: jpeg2000dec.c

static void dequantization_float(int x, int y, Jpeg2000Cblk *cblk,
                                 Jpeg2000Component *comp,
                                 Jpeg2000T1Context *t1, Jpeg2000Band *band)
{
    int i, j;
    int w = cblk->coord[0][1] - cblk->coord[0][0];
    for (j = 0; j < (cblk->coord[1][1] - cblk->coord[1][0]); ++j) {
        float *datap = &comp->f_data[(comp->coord[0][1] - comp->coord[0][0]) * (y + j) + x];
        int *src = t1->data[j];
        for (i = 0; i < w; ++i)
            datap[i] = src[i] * band->f_stepsize;
    }
}

Project: FFmpeg
File: jpeg2000dec.c

static void dequantization_int(int x, int y, Jpeg2000Cblk *cblk,
                               Jpeg2000Component *comp,
                               Jpeg2000T1Context *t1, Jpeg2000Band *band)
{
    int i, j;
    int w = cblk->coord[0][1] - cblk->coord[0][0];
    for (j = 0; j < (cblk->coord[1][1] - cblk->coord[1][0]); ++j) {
        int32_t *datap = &comp->i_data[(comp->coord[0][1] - comp->coord[0][0]) * (y + j) + x];
        int *src = t1->data[j];
        for (i = 0; i < w; ++i)
            datap[i] = (src[i] * band->i_stepsize + (1 << 14)) >> 15;
    }
}

Project: FFmpeg
File: jpeg2000dec.c

static int get_bits(Jpeg2000DecoderContext *s, int n)
{
    int res = 0;

    while (--n >= 0) {
        res <<= 1;
        if (s->bit_index == 0) {
            s->bit_index = 7 + (bytestream2_get_byte(&s->g) != 0xFFu);
        }
        s->bit_index--;
        res |= (bytestream2_peek_byte(&s->g) >> s->bit_index) & 1;
    }
    return res;
}

Project: FFmpeg
File: jpeg2000dec.c

static int get_coc(Jpeg2000DecoderContext *s, Jpeg2000CodingStyle *c,
                   uint8_t *properties)
{
    int compno, ret;

    if (bytestream2_get_bytes_left(&s->g) < 2)
        return AVERROR_INVALIDDATA;

    compno = bytestream2_get_byteu(&s->g);

    if (compno >= s->ncomponents) {
        av_log(s->avctx, AV_LOG_ERROR,
               "Invalid compno %d. There are %d components in the image.\n",
               compno, s->ncomponents);
        return AVERROR_INVALIDDATA;
    }

    c      += compno;
    c->csty = bytestream2_get_byteu(&s->g);

    if ((ret = get_cox(s, c)) < 0)
        return ret;

    properties[compno] |= HAD_COC;
    return 0;
}

Project: FFmpeg

static int get_cod(Jpeg2000DecoderContext *s, Jpeg2000CodingStyle *c,
                   uint8_t *properties)
{
    Jpeg2000CodingStyle tmp;
    int compno, ret;

    if (bytestream2_get_bytes_left(&s->g) < 5)
        return AVERROR_INVALIDDATA;

    tmp.csty = bytestream2_get_byteu(&s->g);

    tmp.prog_order = bytestream2_get_byteu(&s->g);

    tmp.nlayers    = bytestream2_get_be16u(&s->g);
    tmp.mct        = bytestream2_get_byteu(&s->g); // multiple component transformation

    if (tmp.mct && s->ncomponents < 3) {
        av_log(s->avctx, AV_LOG_ERROR,
               "MCT %d with too few components (%d)\n",
               tmp.mct, s->ncomponents);
        return AVERROR_INVALIDDATA;
    }

    if ((ret = get_cox(s, &tmp)) < 0)
        return ret;

    for (compno = 0; compno < s->ncomponents; compno++)
        if (!(properties[compno] & HAD_COC))
            memcpy(c + compno, &tmp, sizeof(tmp));
    return 0;
}

Project: FFmpeg
File: jpeg2000dec.c

static int get_qcc(Jpeg2000DecoderContext *s, int n, Jpeg2000QuantStyle *q,
                   uint8_t *properties)
{
    int compno;

    if (bytestream2_get_bytes_left(&s->g) < 1)
        return AVERROR_INVALIDDATA;

    compno = bytestream2_get_byteu(&s->g);

    if (compno >= s->ncomponents) {
        av_log(s->avctx, AV_LOG_ERROR,
               "Invalid compno %d. There are %d components in the image.\n",
               compno, s->ncomponents);
        return AVERROR_INVALIDDATA;
    }

    properties[compno] |= HAD_QCC;
    return get_qcx(s, n - 1, q + compno);
}

Project: FFmpeg
File: jpeg2000dec.c

static int get_qcx(Jpeg2000DecoderContext *s, int n, Jpeg2000QuantStyle *q)
{
    int i, x;

    if (bytestream2_get_bytes_left(&s->g) < 1)
        return AVERROR_INVALIDDATA;

    x = bytestream2_get_byteu(&s->g); // Sqcd

    q->nguardbits = x >> 5;
    q->quantsty   = x & 0x1f;

    if (q->quantsty == JPEG2000_QSTY_NONE) {
        n -= 3;
        if (bytestream2_get_bytes_left(&s->g) < n ||
            n > JPEG2000_MAX_DECLEVELS*3)
            return AVERROR_INVALIDDATA;
        for (i = 0; i < n; i++)
            q->expn[i] = bytestream2_get_byteu(&s->g) >> 3;
    } else if (q->quantsty == JPEG2000_QSTY_SI) {
        if (bytestream2_get_bytes_left(&s->g) < 2)
            return AVERROR_INVALIDDATA;
        x          = bytestream2_get_be16u(&s->g);
        q->expn[0] = x >> 11;
        q->mant[0] = x & 0x7ff;
        for (i = 1; i < JPEG2000_MAX_DECLEVELS * 3; i++) {
            int curexpn = FFMAX(0, q->expn[0] - (i - 1) / 3);
            q->expn[i] = curexpn;
            q->mant[i] = q->mant[0];
        }
    } else {
        n = (n - 3) >> 1;
        if (bytestream2_get_bytes_left(&s->g) < 2 * n ||
            n > JPEG2000_MAX_DECLEVELS*3)
            return AVERROR_INVALIDDATA;
        for (i = 0; i < n; i++) {
            x          = bytestream2_get_be16u(&s->g);
            q->expn[i] = x >> 11;
            q->mant[i] = x & 0x7ff;
        }
    }
    return 0;
}

Project: FFmpeg
File: jpeg2000dec.c

static int get_sot(Jpeg2000DecoderContext *s, int n)
{
    Jpeg2000TilePart *tp;
    uint16_t Isot;
    uint32_t Psot;
    uint8_t TPsot;

    if (bytestream2_get_bytes_left(&s->g) < 8)
        return AVERROR_INVALIDDATA;

    s->curtileno = 0;
    Isot = bytestream2_get_be16u(&s->g);        // Isot
    if (Isot >= s->numXtiles * s->numYtiles)
        return AVERROR_INVALIDDATA;

    s->curtileno = Isot;
    Psot  = bytestream2_get_be32u(&s->g);       // Psot
    TPsot = bytestream2_get_byteu(&s->g);       // TPsot

    /* Read TNSot but not used */
    bytestream2_get_byteu(&s->g);               // TNsot

    if (Psot > bytestream2_get_bytes_left(&s->g) + n + 2) {
        av_log(s->avctx, AV_LOG_ERROR, "Psot %d too big\n", Psot);
        return AVERROR_INVALIDDATA;
    }

    if (TPsot >= FF_ARRAY_ELEMS(s->tile[Isot].tile_part)) {
        avpriv_request_sample(s->avctx, "Support for %d components", TPsot);
        return AVERROR_PATCHWELCOME;
    }

    s->tile[Isot].tp_idx = TPsot;
    tp             = s->tile[Isot].tile_part + TPsot;
    tp->tile_index = Isot;
    tp->tp_end     = s->g.buffer + Psot - n - 2;

    if (!TPsot) {
        Jpeg2000Tile *tile = s->tile + s->curtileno;

        /* copy defaults */
        memcpy(tile->codsty, s->codsty, s->ncomponents * sizeof(Jpeg2000CodingStyle));
        memcpy(tile->qntsty, s->qntsty, s->ncomponents * sizeof(Jpeg2000QuantStyle));
    }

    return 0;
}

Project: FFmpeg

static uint8_t get_tlm(Jpeg2000DecoderContext *s, int n)
{
    uint8_t Stlm, ST, SP, tile_tlm, i;
    bytestream2_get_byte(&s->g);               /* Ztlm: skipped */
    Stlm = bytestream2_get_byte(&s->g);

    ST = (Stlm >> 4) & 0x03;
    SP       = (Stlm >> 6) & 0x01;
    tile_tlm = (n - 4) / ((SP + 1) * 2 + ST);
    for (i = 0; i < tile_tlm; i++) {
        switch (ST) {
        case 0:
            break;
        case 1:
            bytestream2_get_byte(&s->g);
            break;
        case 2:
            bytestream2_get_be16(&s->g);
            break;
        case 3:
            bytestream2_get_be32(&s->g);
            break;
        }
        if (SP == 0) {
            bytestream2_get_be16(&s->g);
        } else {
            bytestream2_get_be32(&s->g);
        }
    }
    return 0;
}

Project: FFmpeg
File: jpeg2000dec.c

static int getlblockinc(Jpeg2000DecoderContext *s)
{
    int res = 0, ret;
    while (ret = get_bits(s, 1)) {
        if (ret < 0)
            return ret;
        res++;
    }
    return res;
}

Project: FFmpeg
File: jpeg2000dec.c

static int getnpasses(Jpeg2000DecoderContext *s)
{
    int num;
    if (!get_bits(s, 1))
        return 1;
    if (!get_bits(s, 1))
        return 2;
    if ((num = get_bits(s, 2)) != 3)
        return num < 0 ? num : 3 + num;
    if ((num = get_bits(s, 5)) != 31)
        return num < 0 ? num : 6 + num;
    num = get_bits(s, 7);
    return num < 0 ? num : 37 + num;
}

Project: FFmpeg
File: jpeg2000dec.c

static int init_tile(Jpeg2000DecoderContext *s, int tileno)
{
    int compno;
    int tilex = tileno % s->numXtiles;
    int tiley = tileno / s->numXtiles;
    Jpeg2000Tile *tile = s->tile + tileno;

    if (!tile->comp)
        return AVERROR(ENOMEM);

    for (compno = 0; compno < s->ncomponents; compno++) {
        Jpeg2000Component *comp = tile->comp + compno;
        Jpeg2000CodingStyle *codsty = tile->codsty + compno;
        Jpeg2000QuantStyle  *qntsty = tile->qntsty + compno;
        int ret; // global bandno

        comp->coord_o[0][0] = FFMAX(tilex       * s->tile_width  + s->tile_offset_x, s->image_offset_x);
        comp->coord_o[0][1] = FFMIN((tilex + 1) * s->tile_width  + s->tile_offset_x, s->width);
        comp->coord_o[1][0] = FFMAX(tiley       * s->tile_height + s->tile_offset_y, s->image_offset_y);
        comp->coord_o[1][1] = FFMIN((tiley + 1) * s->tile_height + s->tile_offset_y, s->height);

        comp->coord[0][0] = ff_jpeg2000_ceildivpow2(comp->coord_o[0][0], s->reduction_factor);
        comp->coord[0][1] = ff_jpeg2000_ceildivpow2(comp->coord_o[0][1], s->reduction_factor);
        comp->coord[1][0] = ff_jpeg2000_ceildivpow2(comp->coord_o[1][0], s->reduction_factor);
        comp->coord[1][1] = ff_jpeg2000_ceildivpow2(comp->coord_o[1][1], s->reduction_factor);

        if (ret = ff_jpeg2000_init_component(comp, codsty, qntsty,
                                             s->cbps[compno], s->cdx[compno],
                                             s->cdy[compno], s->avctx))
            return ret;
    }
    return 0;
}

Project: FFmpeg

static int jp2_find_codestream(Jpeg2000DecoderContext *s)
{
    uint32_t atom_size, atom, atom_end;
    int search_range = 10;

    while (search_range
           &&
           bytestream2_get_bytes_left(&s->g) >= 8) {
        atom_size = bytestream2_get_be32u(&s->g);
        atom      = bytestream2_get_be32u(&s->g);
        atom_end  = bytestream2_tell(&s->g) + atom_size - 8;

        if (atom == JP2_CODESTREAM)
            return 1;

        if (bytestream2_get_bytes_left(&s->g) < atom_size || atom_end < atom_size)
            return 0;

        if (atom == JP2_HEADER &&
                   atom_size >= 16) {
            uint32_t atom2_size, atom2, atom2_end;
            do {
                atom2_size = bytestream2_get_be32u(&s->g);
                atom2      = bytestream2_get_be32u(&s->g);
                atom2_end  = bytestream2_tell(&s->g) + atom2_size - 8;
                if (atom2_size < 8 || atom2_end > atom_end || atom2_end < atom2_size)
                    break;
                if (atom2 == JP2_CODESTREAM) {
                    return 1;
                } else if (atom2 == MKBETAG('c','o','l','r') && atom2_size >= 7) {
                    int method = bytestream2_get_byteu(&s->g);
                    bytestream2_skipu(&s->g, 2);
                    if (method == 1) {
                        s->colour_space = bytestream2_get_be32u(&s->g);
                    }
                } else if (atom2 == MKBETAG('p','c','l','r') && atom2_size >= 6) {
                    int i, size, colour_count, colour_channels, colour_depth[3];
                    uint32_t r, g, b;
                    colour_count = bytestream2_get_be16u(&s->g);
                    colour_channels = bytestream2_get_byteu(&s->g);
                    colour_depth[0] = (bytestream2_get_byteu(&s->g) & 0x7f) + 1;
                    colour_depth[1] = (bytestream2_get_byteu(&s->g) & 0x7f) + 1;
                    colour_depth[2] = (bytestream2_get_byteu(&s->g) & 0x7f) + 1;
                    size = (colour_depth[0] + 7 >> 3) * colour_count +
                           (colour_depth[1] + 7 >> 3) * colour_count +
                           (colour_depth[2] + 7 >> 3) * colour_count;
                    if (colour_count > 256   ||
                        colour_channels != 3 ||
                        colour_depth[0] > 16 ||
                        colour_depth[1] > 16 ||
                        colour_depth[2] > 16 ||
                        atom2_size < size) {
                        avpriv_request_sample(s->avctx, "Unknown palette");
                        bytestream2_seek(&s->g, atom2_end, SEEK_SET);
                        continue;
                    }
                    s->pal8 = 1;
                    for (i = 0; i < colour_count; i++) {
                        if (colour_depth[0] <= 8) {
                            r = bytestream2_get_byteu(&s->g) << 8 - colour_depth[0];
                            r |= r >> colour_depth[0];
                        } else {
                            r = bytestream2_get_be16u(&s->g) >> colour_depth[0] - 8;
                        }
                        if (colour_depth[1] <= 8) {
                            g = bytestream2_get_byteu(&s->g) << 8 - colour_depth[1];
                            r |= r >> colour_depth[1];
                        } else {
                            g = bytestream2_get_be16u(&s->g) >> colour_depth[1] - 8;
                        }
                        if (colour_depth[2] <= 8) {
                            b = bytestream2_get_byteu(&s->g) << 8 - colour_depth[2];
                            r |= r >> colour_depth[2];
                        } else {
                            b = bytestream2_get_be16u(&s->g) >> colour_depth[2] - 8;
                        }
                        s->palette[i] = 0xffu << 24 | r << 16 | g << 8 | b;
                    }
                } else if (atom2 == MKBETAG('c','d','e','f') && atom2_size >= 2) {
                    int n = bytestream2_get_be16u(&s->g);
                    for (; n>0; n--) {
                        int cn   = bytestream2_get_be16(&s->g);
                        int av_unused typ  = bytestream2_get_be16(&s->g);
                        int asoc = bytestream2_get_be16(&s->g);
                        if (cn < 4 || asoc < 4)
                            s->cdef[cn] = asoc;
                    }
                }
                bytestream2_seek(&s->g, atom2_end, SEEK_SET);
            } while (atom_end - atom2_end >= 8);
        } else {
            search_range--;
        }
        bytestream2_seek(&s->g, atom_end, SEEK_SET);
    }

    return 0;
}

Project: FFmpeg
File: jpeg2000dec.c

static void jpeg2000_dec_cleanup(Jpeg2000DecoderContext *s)
{
    int tileno, compno;
    for (tileno = 0; tileno < s->numXtiles * s->numYtiles; tileno++) {
        if (s->tile[tileno].comp) {
            for (compno = 0; compno < s->ncomponents; compno++) {
                Jpeg2000Component *comp     = s->tile[tileno].comp   + compno;
                Jpeg2000CodingStyle *codsty = s->tile[tileno].codsty + compno;

                ff_jpeg2000_cleanup(comp, codsty);
            }
            av_freep(&s->tile[tileno].comp);
        }
    }
    av_freep(&s->tile);
    memset(s->codsty, 0, sizeof(s->codsty));
    memset(s->qntsty, 0, sizeof(s->qntsty));
    s->numXtiles = s->numYtiles = 0;
}

Project: FFmpeg

static int jpeg2000_decode_frame(AVCodecContext *avctx, void *data,
                                 int *got_frame, AVPacket *avpkt)
{
    Jpeg2000DecoderContext *s = avctx->priv_data;
    ThreadFrame frame = { .f = data };
    AVFrame *picture = data;
    int tileno, ret;

    s->avctx     = avctx;
    bytestream2_init(&s->g, avpkt->data, avpkt->size);
    s->curtileno = -1;
    memset(s->cdef, -1, sizeof(s->cdef));

    if (bytestream2_get_bytes_left(&s->g) < 2) {
        ret = AVERROR_INVALIDDATA;
        goto end;
    }

    if (bytestream2_get_bytes_left(&s->g) >= 12 &&
       (bytestream2_get_be32u(&s->g) == 12) &&
       (bytestream2_get_be32u(&s->g) == JP2_SIG_TYPE) &&
       (bytestream2_get_be32u(&s->g) == JP2_SIG_VALUE)) {
        if (!jp2_find_codestream(s)) {
            av_log(avctx, AV_LOG_ERROR,
                   "Could not find Jpeg2000 codestream atom.\n");
            ret = AVERROR_INVALIDDATA;
            goto end;
        }
    } else {
        bytestream2_seek(&s->g, 0, SEEK_SET);
    }

    while (bytestream2_get_bytes_left(&s->g) >= 3 && bytestream2_peek_be16(&s->g) != JPEG2000_SOC)
        bytestream2_skip(&s->g, 1);

    if (bytestream2_get_be16u(&s->g) != JPEG2000_SOC) {
        av_log(avctx, AV_LOG_ERROR, "SOC marker not present\n");
        ret = AVERROR_INVALIDDATA;
        goto end;
    }
    if (ret = jpeg2000_read_main_headers(s))
        goto end;

    /* get picture buffer */
    if ((ret = ff_thread_get_buffer(avctx, &frame, 0)) < 0)
        goto end;
    picture->pict_type = AV_PICTURE_TYPE_I;
    picture->key_frame = 1;

    if (ret = jpeg2000_read_bitstream_packets(s))
        goto end;

    for (tileno = 0; tileno < s->numXtiles * s->numYtiles; tileno++)
        if (ret = jpeg2000_decode_tile(s, s->tile + tileno, picture))
            goto end;

    jpeg2000_dec_cleanup(s);

    *got_frame = 1;

    if (s->avctx->pix_fmt == AV_PIX_FMT_PAL8)
        memcpy(picture->data[1], s->palette, 256 * sizeof(uint32_t));

    return bytestream2_tell(&s->g);

end:
    jpeg2000_dec_cleanup(s);
    return ret;
}

Project: FFmpeg

static int jpeg2000_decode_packets(Jpeg2000DecoderContext *s, Jpeg2000Tile *tile)
{
    int ret = 0;
    int layno, reslevelno, compno, precno, ok_reslevel;
    int x, y;

    s->bit_index = 8;
    switch (tile->codsty[0].prog_order) {
    case JPEG2000_PGOD_RLCP:
        avpriv_request_sample(s->avctx, "Progression order RLCP");

    case JPEG2000_PGOD_LRCP:
        for (layno = 0; layno < tile->codsty[0].nlayers; layno++) {
            ok_reslevel = 1;
            for (reslevelno = 0; ok_reslevel; reslevelno++) {
                ok_reslevel = 0;
                for (compno = 0; compno < s->ncomponents; compno++) {
                    Jpeg2000CodingStyle *codsty = tile->codsty + compno;
                    Jpeg2000QuantStyle *qntsty  = tile->qntsty + compno;
                    if (reslevelno < codsty->nreslevels) {
                        Jpeg2000ResLevel *rlevel = tile->comp[compno].reslevel +
                                                reslevelno;
                        ok_reslevel = 1;
                        for (precno = 0; precno < rlevel->num_precincts_x * rlevel->num_precincts_y; precno++)
                            if ((ret = jpeg2000_decode_packet(s,
                                                              codsty, rlevel,
                                                              precno, layno,
                                                              qntsty->expn + (reslevelno ? 3 * (reslevelno - 1) + 1 : 0),
                                                              qntsty->nguardbits)) < 0)
                                return ret;
                    }
                }
            }
        }
        break;

    case JPEG2000_PGOD_CPRL:
        for (compno = 0; compno < s->ncomponents; compno++) {
            Jpeg2000CodingStyle *codsty = tile->codsty + compno;
            Jpeg2000QuantStyle *qntsty  = tile->qntsty + compno;

            /* Set bit stream buffer address according to tile-part.
             * For DCinema one tile-part per component, so can be
             * indexed by component. */
            s->g = tile->tile_part[compno].tpg;

            /* Position loop (y axis)
             * TODO: Automate computing of step 256.
             * Fixed here, but to be computed before entering here. */
            for (y = 0; y < s->height; y += 256) {
                /* Position loop (y axis)
                 * TODO: automate computing of step 256.
                 * Fixed here, but to be computed before entering here. */
                for (x = 0; x < s->width; x += 256) {
                    for (reslevelno = 0; reslevelno < codsty->nreslevels; reslevelno++) {
                        uint16_t prcx, prcy;
                        uint8_t reducedresno = codsty->nreslevels - 1 -reslevelno; //  ==> N_L - r
                        Jpeg2000ResLevel *rlevel = tile->comp[compno].reslevel + reslevelno;

                        if (!((y % (1 << (rlevel->log2_prec_height + reducedresno)) == 0) ||
                              (y == 0))) // TODO: 2nd condition simplified as try0 always =0 for dcinema
                            continue;

                        if (!((x % (1 << (rlevel->log2_prec_width + reducedresno)) == 0) ||
                              (x == 0))) // TODO: 2nd condition simplified as try0 always =0 for dcinema
                            continue;

                        prcx   = ff_jpeg2000_ceildivpow2(x, reducedresno) >> rlevel->log2_prec_width;
                        prcy   = ff_jpeg2000_ceildivpow2(y, reducedresno) >> rlevel->log2_prec_height;
                        precno = prcx + rlevel->num_precincts_x * prcy;
                        for (layno = 0; layno < tile->codsty[0].nlayers; layno++) {
                            if ((ret = jpeg2000_decode_packet(s, codsty, rlevel,
                                                              precno, layno,
                                                              qntsty->expn + (reslevelno ? 3 * (reslevelno - 1) + 1 : 0),
                                                              qntsty->nguardbits)) < 0)
                                return ret;
                        }
                    }
                }
            }
        }
        break;

    case JPEG2000_PGOD_RPCL:
        avpriv_request_sample(s->avctx, "Progression order RPCL");
        ret = AVERROR_PATCHWELCOME;
        break;

    case JPEG2000_PGOD_PCRL:
        avpriv_request_sample(s->avctx, "Progression order PCRL");
        ret = AVERROR_PATCHWELCOME;
        break;

    default:
        break;
    }

    /* EOC marker reached */
    bytestream2_skip(&s->g, 2);

    return ret;
}

Project: FFmpeg
File: jpeg2000dec.c

static void jpeg2000_flush(Jpeg2000DecoderContext *s)
{
    if (bytestream2_get_byte(&s->g) == 0xff)
        bytestream2_skip(&s->g, 1);
    s->bit_index = 8;
}

Project: FFmpeg
File: jpeg2000dec.c

static void jpeg2000_init_static_data(AVCodec *codec)
{
    ff_jpeg2000_init_tier1_luts();
    ff_mqc_init_context_tables();
}

Project: FFmpeg
File: jpeg2000dec.c

static int jpeg2000_read_bitstream_packets(Jpeg2000DecoderContext *s)
{
    int ret = 0;
    int tileno;

    for (tileno = 0; tileno < s->numXtiles * s->numYtiles; tileno++) {
        Jpeg2000Tile *tile = s->tile + tileno;

        if (ret = init_tile(s, tileno))
            return ret;

        s->g = tile->tile_part[0].tpg;
        if (ret = jpeg2000_decode_packets(s, tile))
            return ret;
    }

    return 0;
}

Project: FFmpeg
File: jpeg2000dec.c

static void mct_decode(Jpeg2000DecoderContext *s, Jpeg2000Tile *tile)
{
    int i, csize = 1;
    int32_t *src[3],  i0,  i1,  i2;
    float   *srcf[3], i0f, i1f, i2f;

    for (i = 1; i < 3; i++)
        if (tile->codsty[0].transform != tile->codsty[i].transform) {
            av_log(s->avctx, AV_LOG_ERROR, "Transforms mismatch, MCT not supported\n");
            return;
        }

    for (i = 0; i < 3; i++)
        if (tile->codsty[0].transform == FF_DWT97)
            srcf[i] = tile->comp[i].f_data;
        else
            src [i] = tile->comp[i].i_data;

    for (i = 0; i < 2; i++)
        csize *= tile->comp[0].coord[i][1] - tile->comp[0].coord[i][0];

    switch (tile->codsty[0].transform) {
    case FF_DWT97:
        for (i = 0; i < csize; i++) {
            i0f = *srcf[0] + (f_ict_params[0] * *srcf[2]);
            i1f = *srcf[0] - (f_ict_params[1] * *srcf[1])
                           - (f_ict_params[2] * *srcf[2]);
            i2f = *srcf[0] + (f_ict_params[3] * *srcf[1]);
            *srcf[0]++ = i0f;
            *srcf[1]++ = i1f;
            *srcf[2]++ = i2f;
        }
        break;
    case FF_DWT97_INT:
        for (i = 0; i < csize; i++) {
            i0 = *src[0] + (((i_ict_params[0] * *src[2]) + (1 << 15)) >> 16);
            i1 = *src[0] - (((i_ict_params[1] * *src[1]) + (1 << 15)) >> 16)
                         - (((i_ict_params[2] * *src[2]) + (1 << 15)) >> 16);
            i2 = *src[0] + (((i_ict_params[3] * *src[1]) + (1 << 15)) >> 16);
            *src[0]++ = i0;
            *src[1]++ = i1;
            *src[2]++ = i2;
        }
        break;
    case FF_DWT53:
        for (i = 0; i < csize; i++) {
            i1 = *src[0] - (*src[2] + *src[1] >> 2);
            i0 = i1 + *src[2];
            i2 = i1 + *src[1];
            *src[0]++ = i0;
            *src[1]++ = i1;
            *src[2]++ = i2;
        }
        break;
    }
}

Project: FFmpeg
File: jpeg2000dec.c

static int pix_fmt_match(enum AVPixelFormat pix_fmt, int components,
                         int bpc, uint32_t log2_chroma_wh, int pal8)
{
    int match = 1;
    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);

    if (desc->nb_components != components) {
        return 0;
    }

    switch (components) {
    case 4:
        match = match && desc->comp[3].depth_minus1 + 1 >= bpc &&
                         (log2_chroma_wh >> 14 & 3) == 0 &&
                         (log2_chroma_wh >> 12 & 3) == 0;
    case 3:
        match = match && desc->comp[2].depth_minus1 + 1 >= bpc &&
                         (log2_chroma_wh >> 10 & 3) == desc->log2_chroma_w &&
                         (log2_chroma_wh >>  8 & 3) == desc->log2_chroma_h;
    case 2:
        match = match && desc->comp[1].depth_minus1 + 1 >= bpc &&
                         (log2_chroma_wh >>  6 & 3) == desc->log2_chroma_w &&
                         (log2_chroma_wh >>  4 & 3) == desc->log2_chroma_h;

    case 1:
        match = match && desc->comp[0].depth_minus1 + 1 >= bpc &&
                         (log2_chroma_wh >>  2 & 3) == 0 &&
                         (log2_chroma_wh       & 3) == 0 &&
                         (desc->flags & AV_PIX_FMT_FLAG_PAL) == pal8 * AV_PIX_FMT_FLAG_PAL;
    }
    return match;
}

Project: FFmpeg
File: jpeg2000dec.c

static int tag_tree_decode(Jpeg2000DecoderContext *s, Jpeg2000TgtNode *node,
                           int threshold)
{
    Jpeg2000TgtNode *stack[30];
    int sp = -1, curval = 0;

    if (!node)
        return AVERROR_INVALIDDATA;

    while (node && !node->vis) {
        stack[++sp] = node;
        node        = node->parent;
    }

    if (node)
        curval = node->val;
    else
        curval = stack[sp]->val;

    while (curval < threshold && sp >= 0) {
        if (curval < stack[sp]->val)
            curval = stack[sp]->val;
        while (curval < threshold) {
            int ret;
            if ((ret = get_bits(s, 1)) > 0) {
                stack[sp]->vis++;
                break;
            } else if (!ret)
                curval++;
            else
                return ret;
        }
        stack[sp]->val = curval;
        sp--;
    }
    return curval;
}