如何获取AudioComponent的Description类型代码?

I'm trying to understand AudioComponents before instanciate them and understand/use AudioUnits...

我试着在实例化它们之前先理解它们并且理解/使用AudioUnits…

I create an AudioComponentDescription by using wildcards:

我使用通配符创建了一个AudioComponentDescription:

var inDesc = AudioComponentDescription(componentType: OSType(),
                                    componentSubType: OSType(),
                               componentManufacturer: OSType(),
                                      componentFlags: UInt32(0),
                                  componentFlagsMask: UInt32(0))

I look how many AudioComponent there is:

我看看有多少音频元件:

AudioComponentCount(&inDesc) // returns 98 in a playground (ok)

I focus the first AudioComponent by using "nil" as first parameter in AudioComponentFindNext:

我将第一个AudioComponent用“nil”作为AudioComponentFindNext中的第一个参数:

var currentComp = AudioComponentFindNext(nil, &inDesc)

Looking at its name:

看着它的名字:

func getAudioComponentName (componentInit:AudioComponent) -> CFString {
    var componentProp:AudioComponent = componentInit
    var componentNameProp:CFString = "" as CFString
    var unmanagedCurrentCompName:Unmanaged<CFString>?
    AudioComponentCopyName(componentProp, &unmanagedCurrentCompName)
    componentNameProp = unmanagedCurrentCompName!.takeRetainedValue()
    return componentNameProp
}
var currentComponentName:CFString = "" as CFString
currentComponentName = getAudioComponentName(currentComp) // returns "Apple PAC3 Transcoder" (ok)

At this point, the following tries will not be "ok".

此时，下面的尝试将不是“ok”。

I want to know much more about this "Apple PAC3 Transcoder" and its description:

我想了解更多关于这个“Apple PAC3转码器”及其描述:

// Creating an empty AudioComponentDescription
var currentComponentDescription = AudioComponentDescription()
// Gettings currentComp's description (type)
AudioComponentGetDescription(currentComp, &currentComponentDescription)
var compDescType:OSType = currentComponentDescription.componentType // returns 1633903715

At the last line of code, how could I get the letter code described in AUComponent.h:

在最后一行代码中，我如何获得在AUComponent.h中描述的字母代码。

enum
{
    kAudioUnitType_Output                   = 'auou',
    kAudioUnitType_MusicDevice              = 'aumu',
    kAudioUnitType_MusicEffect              = 'aumf',
    kAudioUnitType_FormatConverter          = 'aufc',
    kAudioUnitType_Effect                   = 'aufx',
    kAudioUnitType_Mixer                    = 'aumx',
    kAudioUnitType_Panner                   = 'aupn',
    kAudioUnitType_Generator                = 'augn',
    kAudioUnitType_OfflineEffect            = 'auol',
    kAudioUnitType_MIDIProcessor            = 'aumi'
};

for further compatibility I prefer to not have to reproduce this "enum" in my code.

为了进一步的兼容性，我宁愿不需要在代码中复制这个“enum”。

1 个解决方案

#1

componentType is an OSType which is 4 ASCII character codes packed into 32 bits.

componentType是一种OSType，它是由4个ASCII字符编码组成的32位。

1633903715 in hexadecimal is 0x61636463

十六进制中的1633903715是0x61636463

0x61636463 in ascii is 'acdc' (0x61 = 'a', 0x63 = 'c', etc...)

ascii中的0x61636463是“acdc”(0x61 =“a”，0x63 =“c”等)

#1