static void put_signed_pixels_clamped_c(const int16_t *block,
                                        uint8_t *av_restrict pixels,
                                        ptrdiff_t line_size)
{
    int i, j;

    for (i = 0; i < 8; i++) {
        for (j = 0; j < 8; j++) {
            if (*block < -128)
                *pixels = 0;
            else if (*block > 127)
                *pixels = 255;
            else
                *pixels = (uint8_t) (*block + 128);
            block++;
            pixels++;
        }
        pixels += (line_size - 8);
    }
}

The product dereferences a pointer that it expects to be valid but is NULL.