static int read_header(FFV1Context *f)
{
    uint8_t state[CONTEXT_SIZE];
    int i, j, context_count = -1; //-1 to avoid warning
    RangeCoder *const c = &f->slice_context[0]->c;

     memset(state, 128, sizeof(state));
 
     if (f->version < 2) {
        int chroma_planes, chroma_h_shift, chroma_v_shift, transparency;
         unsigned v= get_symbol(c, state, 0);
         if (v >= 2) {
             av_log(f->avctx, AV_LOG_ERROR, "invalid version %d in ver01 header\n", v);
            return AVERROR_INVALIDDATA;
        }
        f->version = v;
        f->ac      = f->avctx->coder_type = get_symbol(c, state, 0);
        if (f->ac > 1) {
            for (i = 1; i < 256; i++)
                 f->state_transition[i] = get_symbol(c, state, 1) + c->one_state[i];
         }
 
        f->colorspace = get_symbol(c, state, 0); //YUV cs type
        if (f->version > 0)
            f->avctx->bits_per_raw_sample = get_symbol(c, state, 0);
         chroma_planes  = get_rac(c, state);
         chroma_h_shift = get_symbol(c, state, 0);
         chroma_v_shift = get_symbol(c, state, 0);
         transparency   = get_rac(c, state);
 
         if (f->plane_count) {
            if (   chroma_planes != f->chroma_planes
                 || chroma_h_shift!= f->chroma_h_shift
                 || chroma_v_shift!= f->chroma_v_shift
                 || transparency  != f->transparency) {
                av_log(f->avctx, AV_LOG_ERROR, "Invalid change of global parameters\n");
                return AVERROR_INVALIDDATA;
             }
         }
 
         f->chroma_planes  = chroma_planes;
         f->chroma_h_shift = chroma_h_shift;
         f->chroma_v_shift = chroma_v_shift;
        f->transparency   = transparency;

        f->plane_count    = 2 + f->transparency;
    }

    if (f->colorspace == 0) {
        if (!f->transparency && !f->chroma_planes) {
            if (f->avctx->bits_per_raw_sample <= 8)
                f->avctx->pix_fmt = AV_PIX_FMT_GRAY8;
            else
                f->avctx->pix_fmt = AV_PIX_FMT_GRAY16;
        } else if (f->avctx->bits_per_raw_sample<=8 && !f->transparency) {
            switch(16 * f->chroma_h_shift + f->chroma_v_shift) {
            case 0x00: f->avctx->pix_fmt = AV_PIX_FMT_YUV444P; break;
            case 0x01: f->avctx->pix_fmt = AV_PIX_FMT_YUV440P; break;
            case 0x10: f->avctx->pix_fmt = AV_PIX_FMT_YUV422P; break;
            case 0x11: f->avctx->pix_fmt = AV_PIX_FMT_YUV420P; break;
            case 0x20: f->avctx->pix_fmt = AV_PIX_FMT_YUV411P; break;
            case 0x22: f->avctx->pix_fmt = AV_PIX_FMT_YUV410P; break;
            default:
                av_log(f->avctx, AV_LOG_ERROR, "format not supported\n");
                return AVERROR(ENOSYS);
            }
        } else if (f->avctx->bits_per_raw_sample <= 8 && f->transparency) {
            switch(16*f->chroma_h_shift + f->chroma_v_shift) {
            case 0x00: f->avctx->pix_fmt = AV_PIX_FMT_YUVA444P; break;
            case 0x10: f->avctx->pix_fmt = AV_PIX_FMT_YUVA422P; break;
            case 0x11: f->avctx->pix_fmt = AV_PIX_FMT_YUVA420P; break;
            default:
                av_log(f->avctx, AV_LOG_ERROR, "format not supported\n");
                return AVERROR(ENOSYS);
            }
        } else if (f->avctx->bits_per_raw_sample == 9) {
            f->packed_at_lsb = 1;
            switch(16 * f->chroma_h_shift + f->chroma_v_shift) {
            case 0x00: f->avctx->pix_fmt = AV_PIX_FMT_YUV444P9; break;
            case 0x10: f->avctx->pix_fmt = AV_PIX_FMT_YUV422P9; break;
            case 0x11: f->avctx->pix_fmt = AV_PIX_FMT_YUV420P9; break;
            default:
                av_log(f->avctx, AV_LOG_ERROR, "format not supported\n");
                return AVERROR(ENOSYS);
            }
        } else if (f->avctx->bits_per_raw_sample == 10) {
            f->packed_at_lsb = 1;
            switch(16 * f->chroma_h_shift + f->chroma_v_shift) {
            case 0x00: f->avctx->pix_fmt = AV_PIX_FMT_YUV444P10; break;
            case 0x10: f->avctx->pix_fmt = AV_PIX_FMT_YUV422P10; break;
            case 0x11: f->avctx->pix_fmt = AV_PIX_FMT_YUV420P10; break;
            default:
                av_log(f->avctx, AV_LOG_ERROR, "format not supported\n");
                return AVERROR(ENOSYS);
            }
        } else {
            switch(16 * f->chroma_h_shift + f->chroma_v_shift) {
            case 0x00: f->avctx->pix_fmt = AV_PIX_FMT_YUV444P16; break;
            case 0x10: f->avctx->pix_fmt = AV_PIX_FMT_YUV422P16; break;
            case 0x11: f->avctx->pix_fmt = AV_PIX_FMT_YUV420P16; break;
            default:
                av_log(f->avctx, AV_LOG_ERROR, "format not supported\n");
                return AVERROR(ENOSYS);
            }
        }
    } else if (f->colorspace == 1) {
        if (f->chroma_h_shift || f->chroma_v_shift) {
            av_log(f->avctx, AV_LOG_ERROR,
                   "chroma subsampling not supported in this colorspace\n");
            return AVERROR(ENOSYS);
        }
        if (     f->avctx->bits_per_raw_sample ==  9)
            f->avctx->pix_fmt = AV_PIX_FMT_GBRP9;
        else if (f->avctx->bits_per_raw_sample == 10)
            f->avctx->pix_fmt = AV_PIX_FMT_GBRP10;
        else if (f->avctx->bits_per_raw_sample == 12)
            f->avctx->pix_fmt = AV_PIX_FMT_GBRP12;
        else if (f->avctx->bits_per_raw_sample == 14)
            f->avctx->pix_fmt = AV_PIX_FMT_GBRP14;
        else
        if (f->transparency) f->avctx->pix_fmt = AV_PIX_FMT_RGB32;
        else                 f->avctx->pix_fmt = AV_PIX_FMT_0RGB32;
    } else {
        av_log(f->avctx, AV_LOG_ERROR, "colorspace not supported\n");
        return AVERROR(ENOSYS);
    }

    av_dlog(f->avctx, "%d %d %d\n",
            f->chroma_h_shift, f->chroma_v_shift, f->avctx->pix_fmt);
    if (f->version < 2) {
        context_count = read_quant_tables(c, f->quant_table);
        if (context_count < 0) {
            av_log(f->avctx, AV_LOG_ERROR, "read_quant_table error\n");
            return AVERROR_INVALIDDATA;
        }
    } else if (f->version < 3) {
        f->slice_count = get_symbol(c, state, 0);
    } else {
        const uint8_t *p = c->bytestream_end;
        for (f->slice_count = 0;
             f->slice_count < MAX_SLICES && 3 < p - c->bytestream_start;
             f->slice_count++) {
            int trailer = 3 + 5*!!f->ec;
            int size = AV_RB24(p-trailer);
            if (size + trailer > p - c->bytestream_start)
                break;
            p -= size + trailer;
        }
    }
    if (f->slice_count > (unsigned)MAX_SLICES || f->slice_count <= 0) {
        av_log(f->avctx, AV_LOG_ERROR, "slice count %d is invalid\n", f->slice_count);
        return AVERROR_INVALIDDATA;
    }

    for (j = 0; j < f->slice_count; j++) {
        FFV1Context *fs = f->slice_context[j];
        fs->ac            = f->ac;
        fs->packed_at_lsb = f->packed_at_lsb;

        fs->slice_damaged = 0;

        if (f->version == 2) {
            fs->slice_x      =  get_symbol(c, state, 0)      * f->width ;
            fs->slice_y      =  get_symbol(c, state, 0)      * f->height;
            fs->slice_width  = (get_symbol(c, state, 0) + 1) * f->width  + fs->slice_x;
            fs->slice_height = (get_symbol(c, state, 0) + 1) * f->height + fs->slice_y;

            fs->slice_x     /= f->num_h_slices;
            fs->slice_y     /= f->num_v_slices;
            fs->slice_width  = fs->slice_width  / f->num_h_slices - fs->slice_x;
            fs->slice_height = fs->slice_height / f->num_v_slices - fs->slice_y;
            if ((unsigned)fs->slice_width  > f->width ||
                (unsigned)fs->slice_height > f->height)
                return AVERROR_INVALIDDATA;
            if (   (unsigned)fs->slice_x + (uint64_t)fs->slice_width  > f->width
                || (unsigned)fs->slice_y + (uint64_t)fs->slice_height > f->height)
                return AVERROR_INVALIDDATA;
        }

        for (i = 0; i < f->plane_count; i++) {
            PlaneContext *const p = &fs->plane[i];

            if (f->version == 2) {
                int idx = get_symbol(c, state, 0);
                if (idx > (unsigned)f->quant_table_count) {
                    av_log(f->avctx, AV_LOG_ERROR,
                           "quant_table_index out of range\n");
                    return AVERROR_INVALIDDATA;
                }
                p->quant_table_index = idx;
                memcpy(p->quant_table, f->quant_tables[idx],
                       sizeof(p->quant_table));
                context_count = f->context_count[idx];
            } else {
                memcpy(p->quant_table, f->quant_table, sizeof(p->quant_table));
            }

            if (f->version <= 2) {
                av_assert0(context_count >= 0);
                if (p->context_count < context_count) {
                    av_freep(&p->state);
                    av_freep(&p->vlc_state);
                }
                p->context_count = context_count;
            }
        }
    }
    return 0;
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.