static void alpha_inverse_prediction(AVFrame *frame, enum AlphaFilter m)
{
    int x, y, ls;
    uint8_t *dec;

    ls = frame->linesize[3];

    /* filter first row using horizontal filter */
    dec = frame->data[3] + 1;
    for (x = 1; x < frame->width; x++, dec++)
        *dec += *(dec - 1);

    /* filter first column using vertical filter */
    dec = frame->data[3] + ls;
    for (y = 1; y < frame->height; y++, dec += ls)
        *dec += *(dec - ls);

    /* filter the rest using the specified filter */
    switch (m) {
    case ALPHA_FILTER_HORIZONTAL:
        for (y = 1; y < frame->height; y++) {
            dec = frame->data[3] + y * ls + 1;
            for (x = 1; x < frame->width; x++, dec++)
                *dec += *(dec - 1);
        }
        break;
    case ALPHA_FILTER_VERTICAL:
        for (y = 1; y < frame->height; y++) {
            dec = frame->data[3] + y * ls + 1;
            for (x = 1; x < frame->width; x++, dec++)
                *dec += *(dec - ls);
        }
        break;
    case ALPHA_FILTER_GRADIENT:
        for (y = 1; y < frame->height; y++) {
            dec = frame->data[3] + y * ls + 1;
            for (x = 1; x < frame->width; x++, dec++)
                dec[0] += av_clip_uint8(*(dec - 1) + *(dec - ls) - *(dec - ls - 1));
        }
        break;
    }
}

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.