如何读取屏幕EDID数据？

Question

我在试着解析屏幕的EDID信息。不幸的是，它不是任何常见的编码数据。您是否知道如何将“IODisplayEDID”中的数据转换为可读的数据？也许是“字典”？

下面是我的代码：

    var object : io_object_t
    var serialPortIterator = io_iterator_t()
    let matching = IOServiceMatching("IODisplayConnect")

    let kernResult = IOServiceGetMatchingServices(kIOMasterPortDefault,
                                                  matching,
                                                  &serialPortIterator)
    if KERN_SUCCESS == kernResult && serialPortIterator != 0 {
        repeat {
            object = IOIteratorNext(serialPortIterator)
            let info = IODisplayCreateInfoDictionary(object, UInt32(kIODisplayOnlyPreferredName)).takeRetainedValue() as NSDictionary as! [String:AnyObject]

            if let displayEDID = info["IODisplayEDID"] as? Data {

                print(displayEDID) // <-- How do I parse this data correctly?
            }

        } while object != 0
    }
    IOObjectRelease(serialPortIterator)

Answer 1

好的，所以基本上我使用了评论中提供的维基参考Eric Aya。我按照指定的顺序读取8-9个字节，以提取字母表的树形编号。在我的mac上，结果显示为"APP“，我猜这意味着制造商是苹果。

            if let displayEDID = info["IODisplayEDID"] as? Data {

                let array = Array(displayEDID)

                var bits : UInt16 = UInt16(array[8])
                bits = bits << 8  + UInt16(array[9])

                let thirdLetterIndex = Int(bits & 31)
                let secondLetterIndex = Int(bits >> 5 & 31)
                let firsLetterIndex = Int(bits >> 10 & 31)


                let chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ".characters.flatMap { $0.description }
                let manufactorer = chars[firsLetterIndex - 1] + chars[secondLetterIndex - 1] + chars[thirdLetterIndex - 1]


                print(manufactorer) // Result for my mac is "APP"
            }