/**
 * Read a run length encoded SGI image.
 * @param out_buf output buffer
 * @param s the current image state
 * @return 0 if no error, else return error code.
 */
static int read_rle_sgi(uint8_t *out_buf, SgiState *s)
{
    uint8_t *dest_row;
    unsigned int len = s->height * s->depth * 4;
    GetByteContext g_table = s->g;
    unsigned int y, z;
    unsigned int start_offset;
    int linesize, ret;

    /* size of  RLE offset and length tables */
    if (len * 2 > bytestream2_get_bytes_left(&s->g)) {
        return AVERROR_INVALIDDATA;
    }

    for (z = 0; z < s->depth; z++) {
        dest_row = out_buf;
        for (y = 0; y < s->height; y++) {
            linesize = s->width * s->depth * s->bytes_per_channel;
            dest_row -= s->linesize;
            start_offset = bytestream2_get_be32(&g_table);
            bytestream2_seek(&s->g, start_offset, SEEK_SET);
            if (s->bytes_per_channel == 1)
                ret = expand_rle_row8(s, dest_row + z, linesize, s->depth);
            else
                ret = expand_rle_row16(s, (uint16_t *)dest_row + z, linesize, s->depth);
            if (ret != s->width)
                return AVERROR_INVALIDDATA;
        }
    }
    return 0;
}

/**
 * Expand an RLE row into a channel.
 * @param s the current image state
 * @param out_buf Points to one line after the output buffer.
 * @param out_end end of line in output buffer
 * @param pixelstride pixel stride of input buffer
 * @return size of output in bytes, -1 if buffer overflows
 */
static int expand_rle_row(SgiState *s, uint8_t *out_buf,
                          uint8_t *out_end, int pixelstride)
{
    unsigned char pixel, count;
    unsigned char *orig = out_buf;

    while (1) {
        if (bytestream2_get_bytes_left(&s->g) < 1)
            return AVERROR_INVALIDDATA;
        pixel = bytestream2_get_byteu(&s->g);
        if (!(count = (pixel & 0x7f))) {
            return (out_buf - orig) / pixelstride;
        }

        /* Check for buffer overflow. */
        if(out_buf + pixelstride * count >= out_end) return -1;

        if (pixel & 0x80) {
            while (count--) {
                *out_buf = bytestream2_get_byte(&s->g);
                out_buf += pixelstride;
            }
        } else {
            pixel = bytestream2_get_byte(&s->g);

            while (count--) {
                *out_buf = pixel;
                out_buf += pixelstride;
            }
        }
    }
}

static int gif_parse_next_image(GifState *s, AVFrame *frame)
{
    while (bytestream2_get_bytes_left(&s->gb) > 0) {
        int code = bytestream2_get_byte(&s->gb);
        int ret;

        av_log(s->avctx, AV_LOG_DEBUG, "code=%02x '%c'\n", code, code);

        switch (code) {
        case GIF_IMAGE_SEPARATOR:
            return gif_read_image(s, frame);
        case GIF_EXTENSION_INTRODUCER:
            if ((ret = gif_read_extension(s)) < 0)
                return ret;
            break;
        case GIF_TRAILER:
            /* end of image */
            return AVERROR_EOF;
        default:
            /* erroneous block label */
            return AVERROR_INVALIDDATA;
        }
    }
    return AVERROR_EOF;
}

/**
 * Read a run length encoded SGI image.
 * @param out_buf output buffer
 * @param s the current image state
 * @return 0 if no error, else return error number.
 */
static int read_rle_sgi(uint8_t *out_buf, SgiState *s)
{
    uint8_t *dest_row;
    unsigned int len = s->height * s->depth * 4;
    GetByteContext g_table = s->g;
    unsigned int y, z;
    unsigned int start_offset;

    /* size of  RLE offset and length tables */
    if (len * 2  > bytestream2_get_bytes_left(&s->g)) {
        return AVERROR_INVALIDDATA;
    }

    for (z = 0; z < s->depth; z++) {
        dest_row = out_buf;
        for (y = 0; y < s->height; y++) {
            dest_row -= s->linesize;
            start_offset = bytestream2_get_be32(&g_table);
            bytestream2_seek(&s->g, start_offset, SEEK_SET);
            if (expand_rle_row(s, dest_row + z, dest_row + FFABS(s->linesize),
                               s->depth) != s->width) {
                return AVERROR_INVALIDDATA;
            }
        }
    }
    return 0;
}

/** get coding parameters for a particular tile or whole image*/
static int get_cod(J2kDecoderContext *s, J2kCodingStyle *c, uint8_t *properties)
{
    J2kCodingStyle tmp;
    int compno;

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

    tmp.log2_prec_width  =
        tmp.log2_prec_height = 15;

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

    if (bytestream2_get_byteu(&s->g)) { // progression level
        av_log(s->avctx, AV_LOG_ERROR, "only LRCP progression supported\n");
        return -1;
    }

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

    get_cox(s, &tmp);
    for (compno = 0; compno < s->ncomponents; compno++) {
        if (!(properties[compno] & HAD_COC))
            memcpy(c + compno, &tmp, sizeof(J2kCodingStyle));
    }
    return 0;
}

/**
 * @return <0 on error
 */
static int tgq_decode_mb(TgqContext *s, int mb_y, int mb_x){
    int mode;
    int i;
    int8_t dc[6];

    mode = bytestream2_get_byte(&s->gb);
    if (mode>12) {
        GetBitContext gb;
        init_get_bits(&gb, s->gb.buffer, FFMIN(bytestream2_get_bytes_left(&s->gb), mode) * 8);
        for(i=0; i<6; i++)
            tgq_decode_block(s, s->block[i], &gb);
        tgq_idct_put_mb(s, s->block, mb_x, mb_y);
        bytestream2_skip(&s->gb, mode);
    }else{
        if (mode==3) {
            memset(dc, bytestream2_get_byte(&s->gb), 4);
            dc[4] = bytestream2_get_byte(&s->gb);
            dc[5] = bytestream2_get_byte(&s->gb);
        }else if (mode==6) {
            bytestream2_get_buffer(&s->gb, dc, 6);
        }else if (mode==12) {
            for (i = 0; i < 6; i++) {
                dc[i] = bytestream2_get_byte(&s->gb);
                bytestream2_skip(&s->gb, 1);
            }
        }else{
            av_log(s->avctx, AV_LOG_ERROR, "unsupported mb mode %i\n", mode);
            return -1;
        }
        tgq_idct_put_mb_dconly(s, mb_x, mb_y, dc);
    }
    return 0;
}

/**
 * Read an uncompressed SGI image.
 * @param out_buf output buffer
 * @param s the current image state
 * @return 0 if read success, else return error code.
 */
static int read_uncompressed_sgi(unsigned char *out_buf, SgiState *s)
{
    int x, y, z;
    unsigned int offset = s->height * s->width * s->bytes_per_channel;
    GetByteContext gp[4];
    uint8_t *out_end;

    /* Test buffer size. */
    if (offset * s->depth > bytestream2_get_bytes_left(&s->g))
        return AVERROR_INVALIDDATA;

    /* Create a reader for each plane */
    for (z = 0; z < s->depth; z++) {
        gp[z] = s->g;
        bytestream2_skip(&gp[z], z * offset);
    }

    for (y = s->height - 1; y >= 0; y--) {
        out_end = out_buf + (y * s->linesize);
        if (s->bytes_per_channel == 1) {
            for (x = s->width; x > 0; x--)
                for (z = 0; z < s->depth; z++)
                    *out_end++ = bytestream2_get_byteu(&gp[z]);
        } else {
            uint16_t *out16 = (uint16_t *)out_end;
            for (x = s->width; x > 0; x--)
                for (z = 0; z < s->depth; z++)
                    *out16++ = bytestream2_get_ne16u(&gp[z]);
        }
    }
    return 0;
}

/**
 * Perform decode operation
 * @param dst     pointer to destination image buffer
 * @param dst_end pointer to end of destination image buffer
 * @param gb GetByteContext (optional, see below)
 * @param pixel Fill color (optional, see below)
 * @param count Pixel count
 * @param x Pointer to x-axis counter
 * @param width Image width
 * @param linesize Destination image buffer linesize
 * @return non-zero if destination buffer is exhausted
 *
 * a copy operation is achieved when 'gb' is set
 * a fill operation is achieved when 'gb' is null and pixel is >= 0
 * a skip operation is achieved when 'gb' is null and pixel is < 0
 */
static inline int op(uint8_t **dst, const uint8_t *dst_end,
                     GetByteContext *gb,
                     int pixel, int count,
                     int *x, int width, int linesize)
{
  int remaining = width - *x;
  while(count > 0) {
    int striplen = FFMIN(count, remaining);
    if (gb) {
      if (bytestream2_get_bytes_left(gb) < striplen)
        goto exhausted;
      bytestream2_get_bufferu(gb, *dst, striplen);
    } else if (pixel >= 0)
      memset(*dst, pixel, striplen);
    *dst      += striplen;
    remaining -= striplen;
    count     -= striplen;
    if (remaining <= 0) {
      *dst      += linesize - width;
      remaining  = width;
    }
    if (linesize > 0) {
      if (*dst >= dst_end) goto exhausted;
    } else {
      if (*dst <= dst_end) goto exhausted;
    }
  }
  *x = width - remaining;
  return 0;

  exhausted:
  *x = width - remaining;
  return 1;
}

/*
 * @param half_horiz Half horizontal resolution (0 or 1)
 * @param half_vert Half vertical resolution (0 or 1)
 */
static int mm_decode_inter(MmContext * s, int half_horiz, int half_vert)
{
    int data_off = bytestream2_get_le16(&s->gb), y;
    GetByteContext data_ptr;

    if (bytestream2_get_bytes_left(&s->gb) < data_off)
        return AVERROR_INVALIDDATA;

    bytestream2_init(&data_ptr, s->gb.buffer + data_off, bytestream2_get_bytes_left(&s->gb) - data_off);
    while (s->gb.buffer < data_ptr.buffer_start) {
        int i, j;
        int length = bytestream2_get_byte(&s->gb);
        int x = bytestream2_get_byte(&s->gb) + ((length & 0x80) << 1);
        length &= 0x7F;

        if (length==0) {
            y += x;
            continue;
        }

        if (y + half_vert >= s->avctx->height)
            return 0;

        for(i=0; i<length; i++) {
            int replace_array = bytestream2_get_byte(&s->gb);
            for(j=0; j<8; j++) {
                int replace = (replace_array >> (7-j)) & 1;
                if (replace) {
                    int color = bytestream2_get_byte(&data_ptr);
                    s->frame.data[0][y*s->frame.linesize[0] + x] = color;
                    if (half_horiz)
                        s->frame.data[0][y*s->frame.linesize[0] + x + 1] = color;
                    if (half_vert) {
                        s->frame.data[0][(y+1)*s->frame.linesize[0] + x] = color;
                        if (half_horiz)
                            s->frame.data[0][(y+1)*s->frame.linesize[0] + x + 1] = color;
                    }
                }
                x += 1 + half_horiz;
            }
        }

        y += 1 + half_vert;
    }

    return 0;
}

/* There are (invalid) samples in the wild with mp4-style extradata, where the
 * parameter sets are stored unescaped (i.e. as RBSP).
 * This function catches the parameter set decoding failure and tries again
 * after escaping it */
static int decode_extradata_ps_mp4(const uint8_t *buf, int buf_size, H264ParamSets *ps,
                                   int err_recognition, void *logctx)
{
    int ret;

    ret = decode_extradata_ps(buf, buf_size, ps, 1, logctx);
    if (ret < 0 && !(err_recognition & AV_EF_EXPLODE)) {
        GetByteContext gbc;
        PutByteContext pbc;
        uint8_t *escaped_buf;
        int escaped_buf_size;

        av_log(logctx, AV_LOG_WARNING,
               "SPS decoding failure, trying again after escaping the NAL\n");

        if (buf_size / 2 >= (INT16_MAX - AV_INPUT_BUFFER_PADDING_SIZE) / 3)
            return AVERROR(ERANGE);
        escaped_buf_size = buf_size * 3 / 2 + AV_INPUT_BUFFER_PADDING_SIZE;
        escaped_buf = av_mallocz(escaped_buf_size);
        if (!escaped_buf)
            return AVERROR(ENOMEM);

        bytestream2_init(&gbc, buf, buf_size);
        bytestream2_init_writer(&pbc, escaped_buf, escaped_buf_size);

        while (bytestream2_get_bytes_left(&gbc)) {
            if (bytestream2_get_bytes_left(&gbc) >= 3 &&
                bytestream2_peek_be24(&gbc) <= 3) {
                bytestream2_put_be24(&pbc, 3);
                bytestream2_skip(&gbc, 2);
            } else
                bytestream2_put_byte(&pbc, bytestream2_get_byte(&gbc));
        }

        escaped_buf_size = bytestream2_tell_p(&pbc);
        AV_WB16(escaped_buf, escaped_buf_size - 2);

        ret = decode_extradata_ps(escaped_buf, escaped_buf_size, ps, 1, logctx);
        av_freep(&escaped_buf);
        if (ret < 0)
            return ret;
    }

    return 0;
}

static int gif_read_header1(GifState *s)
{
    uint8_t sig[6];
    int v, n;
    int has_global_palette;

    if (bytestream2_get_bytes_left(&s->gb) < 13)
        return AVERROR_INVALIDDATA;

    /* read gif signature */
    bytestream2_get_buffer(&s->gb, sig, 6);
    if (memcmp(sig, gif87a_sig, 6) != 0 &&
            memcmp(sig, gif89a_sig, 6) != 0)
        return AVERROR_INVALIDDATA;

    /* read screen header */
    s->transparent_color_index = -1;
    s->screen_width  = bytestream2_get_le16(&s->gb);
    s->screen_height = bytestream2_get_le16(&s->gb);
    if(   (unsigned)s->screen_width  > 32767
            || (unsigned)s->screen_height > 32767) {
        av_log(NULL, AV_LOG_ERROR, "picture size too large\n");
        return AVERROR_INVALIDDATA;
    }

    v = bytestream2_get_byte(&s->gb);
    s->color_resolution = ((v & 0x70) >> 4) + 1;
    has_global_palette = (v & 0x80);
    s->bits_per_pixel = (v & 0x07) + 1;
    s->background_color_index = bytestream2_get_byte(&s->gb);
    bytestream2_get_byte(&s->gb);                /* ignored */

    av_dlog(s->avctx, "gif: screen_w=%d screen_h=%d bpp=%d global_palette=%d\n",
            s->screen_width, s->screen_height, s->bits_per_pixel,
            has_global_palette);

    if (has_global_palette) {
        n = 1 << s->bits_per_pixel;
        if (bytestream2_get_bytes_left(&s->gb) < n * 3)
            return AVERROR_INVALIDDATA;
        bytestream2_get_buffer(&s->gb, s->global_palette, n * 3);
    }
    return 0;
}

/** get common part for QCD and QCC segments */
static int get_qcx(J2kDecoderContext *s, int n, J2kQuantStyle *q)
{
    int i, x;

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

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

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

    if (q->quantsty == J2K_QSTY_NONE){
        n -= 3;
        if (bytestream2_get_bytes_left(&s->g) < n || 32*3 < n)
            return AVERROR(EINVAL);
        for (i = 0; i < n; i++)
            q->expn[i] = bytestream2_get_byteu(&s->g) >> 3;
    } else if (q->quantsty == J2K_QSTY_SI){

static int hq_hqa_decode_frame(AVCodecContext *avctx, void *data,
                               int *got_frame, AVPacket *avpkt)
{
    HQContext *ctx = avctx->priv_data;
    AVFrame *pic = data;
    uint32_t info_tag;
    unsigned int data_size;
    int ret;
    unsigned tag;

    bytestream2_init(&ctx->gbc, avpkt->data, avpkt->size);
    if (bytestream2_get_bytes_left(&ctx->gbc) < 4 + 4) {
        av_log(avctx, AV_LOG_ERROR, "Frame is too small (%d).\n", avpkt->size);
        return AVERROR_INVALIDDATA;
    }

    info_tag = bytestream2_peek_le32(&ctx->gbc);
    if (info_tag == MKTAG('I', 'N', 'F', 'O')) {
        int info_size;
        bytestream2_skip(&ctx->gbc, 4);
        info_size = bytestream2_get_le32(&ctx->gbc);
        if (bytestream2_get_bytes_left(&ctx->gbc) < info_size) {
            av_log(avctx, AV_LOG_ERROR, "Invalid INFO size (%d).\n", info_size);
            return AVERROR_INVALIDDATA;
        }
        ff_canopus_parse_info_tag(avctx, ctx->gbc.buffer, info_size);

        bytestream2_skip(&ctx->gbc, info_size);
    }

    data_size = bytestream2_get_bytes_left(&ctx->gbc);
    if (data_size < 4) {
        av_log(avctx, AV_LOG_ERROR, "Frame is too small (%d).\n", data_size);
        return AVERROR_INVALIDDATA;
    }

    /* HQ defines dimensions and number of slices, and thus slice traversal
     * order. HQA has no size constraint and a fixed number of slices, so it
     * needs a separate scheme for it. */
    tag = bytestream2_get_le32(&ctx->gbc);
    if ((tag & 0x00FFFFFF) == (MKTAG('U', 'V', 'C', ' ') & 0x00FFFFFF)) {
        ret = hq_decode_frame(ctx, pic, tag >> 24, data_size);
    } else if (tag == MKTAG('H', 'Q', 'A', '1')) {

/*
 * To be a valid APNG file, we mandate, in this order:
 *     PNGSIG
 *     IHDR
 *     ...
 *     acTL
 *     ...
 *     IDAT
 */
static int apng_probe(AVProbeData *p)
{
    GetByteContext gb;
    int state = 0;
    uint32_t len, tag;

    bytestream2_init(&gb, p->buf, p->buf_size);

    if (bytestream2_get_be64(&gb) != PNGSIG)
        return 0;

    for (;;) {
        len = bytestream2_get_be32(&gb);
        if (len > 0x7fffffff)
            return 0;

        tag = bytestream2_get_le32(&gb);
        /* we don't check IDAT size, as this is the last tag
         * we check, and it may be larger than the probe buffer */
        if (tag != MKTAG('I', 'D', 'A', 'T') &&
            len > bytestream2_get_bytes_left(&gb))
            return 0;

        switch (tag) {
        case MKTAG('I', 'H', 'D', 'R'):
            if (len != 13)
                return 0;
            if (av_image_check_size(bytestream2_get_be32(&gb), bytestream2_get_be32(&gb), 0, NULL))
                return 0;
            bytestream2_skip(&gb, 9);
            state++;
            break;
        case MKTAG('a', 'c', 'T', 'L'):
            if (state != 1 ||
                len != 8 ||
                bytestream2_get_be32(&gb) == 0) /* 0 is not a valid value for number of frames */
                return 0;
            bytestream2_skip(&gb, 8);
            state++;
            break;
        case MKTAG('I', 'D', 'A', 'T'):
            if (state != 2)
                return 0;
            goto end;
        default:
            /* skip other tags */
            bytestream2_skip(&gb, len + 4);
            break;
        }
    }

end:
    return AVPROBE_SCORE_MAX;
}

/* The first three bytes are the size of the section past the header, or zero
 * if the length is stored in the next long word. The fourth byte in the first
 * long word indicates the type of the current section. */
static int parse_section_header(GetByteContext *gbc, int *section_size,
                                enum HapSectionType *section_type)
{
    if (bytestream2_get_bytes_left(gbc) < 4)
        return AVERROR_INVALIDDATA;

    *section_size = bytestream2_get_le24(gbc);
    *section_type = bytestream2_get_byte(gbc);

    if (*section_size == 0) {
        if (bytestream2_get_bytes_left(gbc) < 4)
            return AVERROR_INVALIDDATA;

        *section_size = bytestream2_get_le32(gbc);
    }

    if (*section_size > bytestream2_get_bytes_left(gbc) || *section_size < 0)
        return AVERROR_INVALIDDATA;
    else
        return 0;
}

static int decode(GetByteContext *gb, RangeCoder *rc, unsigned cumFreq, unsigned freq, unsigned total_freq)
{
    rc->code -= cumFreq * rc->range;
    rc->range *= freq;

    while (rc->range < TOP && bytestream2_get_bytes_left(gb) > 0) {
        unsigned byte = bytestream2_get_byte(gb);
        rc->code = (rc->code << 8) | byte;
        rc->range <<= 8;
    }

    return 0;
}

static int decode_rle(AVCodecContext *avctx, AVFrame *p, GetByteContext *gbc,
                      int step)
{
    int i, j;
    int offset = avctx->width * step;
    uint8_t *outdata = p->data[0];

    for (i = 0; i < avctx->height; i++) {
        int size, left, code, pix;
        uint8_t *out = outdata;
        int pos = 0;

        /* size of packed line */
        size = left = bytestream2_get_be16(gbc);
        if (bytestream2_get_bytes_left(gbc) < size)
            return AVERROR_INVALIDDATA;

        /* decode line */
        while (left > 0) {
            code = bytestream2_get_byte(gbc);
            if (code & 0x80 ) { /* run */
                pix = bytestream2_get_byte(gbc);
                for (j = 0; j < 257 - code; j++) {
                    out[pos] = pix;
                    pos += step;
                    if (pos >= offset) {
                        pos -= offset;
                        pos++;
                    }
                    if (pos >= offset)
                        return AVERROR_INVALIDDATA;
                }
                left  -= 2;
            } else { /* copy */
                for (j = 0; j < code + 1; j++) {
                    out[pos] = bytestream2_get_byte(gbc);
                    pos += step;
                    if (pos >= offset) {
                        pos -= offset;
                        pos++;
                    }
                    if (pos >= offset)
                        return AVERROR_INVALIDDATA;
                }
                left  -= 2 + code;
            }
        }
        outdata += p->linesize[0];
    }
    return 0;
}

static int set_palette(BethsoftvidContext *ctx)
{
    uint32_t *palette = (uint32_t *)ctx->frame.data[1];
    int a;

    if (bytestream2_get_bytes_left(&ctx->g) < 256*3)
        return AVERROR_INVALIDDATA;

    for(a = 0; a < 256; a++){
        palette[a] = bytestream2_get_be24u(&ctx->g) * 4;
    }
    ctx->frame.palette_has_changed = 1;
    return 0;
}

/* The first three bytes are the size of the section past the header, or zero
 * if the length is stored in the next long word. The fourth byte in the first
 * long word indicates the type of the current section. */
static int parse_section_header(AVCodecContext *avctx)
{
    HapContext *ctx = avctx->priv_data;
    GetByteContext *gbc = &ctx->gbc;
    int length;

    if (bytestream2_get_bytes_left(gbc) < 4)
        return AVERROR_INVALIDDATA;

    length = bytestream2_get_le24(gbc);

    ctx->section_type = bytestream2_get_byte(gbc);

    if (length == 0) {
        if (bytestream2_get_bytes_left(gbc) < 4)
            return AVERROR_INVALIDDATA;
        length = bytestream2_get_le32(gbc);
    }

    if (length > bytestream2_get_bytes_left(gbc) || length == 0)
        return AVERROR_INVALIDDATA;

    return length;
}

/** get coding parameters for a component in the whole image on a particular tile */
static int get_coc(J2kDecoderContext *s, J2kCodingStyle *c, uint8_t *properties)
{
    int compno;

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

    compno = bytestream2_get_byteu(&s->g);

    c += compno;
    c->csty = bytestream2_get_byte(&s->g);
    get_cox(s, c);

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