void ff_amf_write_number(uint8_t **dst, double val)
{
    bytestream_put_byte(dst, AMF_DATA_TYPE_NUMBER);
    bytestream_put_be64(dst, av_double2int(val));
}

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.