How to translate CoreMIDI error numbers?

[stephenk]

I’m seeing some errors in Xcode such as:

CoreMIDI error: 56 - ffffffce
CoreMIDI error: 62 - ffffffce
CoreMIDI error: 338 - ffffffce

Does anyone now what the ffffffce means?

I saw in another thread here that said that "a CoreMIDI error of ffffd5a4 was kMIDINotPermitted" - which Apple defines to -10844. So how does one get -10844 from fffd5a4?

[matkatmusic]

https://developer.apple.com/documentation/coremidi/1495156-error_constants?language=objc ?

[stephenk]

Thanks, I already had found that page. But those errors are all like -10830 to -10845. I’m not understanding how to translate something like ffffffce to one of those errors… probably I’m just missing something obvious…

[matkatmusic]

maybe it’s one of those 2’s complement thing or something? or like, convert that -10830 from signed uint16 to unsigned, and see what you get? Your guess is as good as mine…

[mcmartin]

@stephenk

So how does one get -10844 from fffd5a4?

By interpreting the highest bit as the negative sign and using 2’s complement as @matkatmusic suggested:

This only works when the integer size is set to DWORD.

Here is the translation of Core MIDI Error Constants:

kMIDIInvalidClient     | -10830 | ffffd5b2
kMIDIInvalidPort       | -10831 | ffffd5b1
kMIDIWrongEndpointType | -10832 | ffffd5b0
kMIDINoConnection      | -10833 | ffffd5af
kMIDIUnknownEndpoint   | -10834 | ffffd5ae
kMIDIUnknownProperty   | -10835 | ffffd5ad
kMIDIWrongPropertyType | -10836 | ffffd5ac
kMIDINoCurrentSetup    | -10837 | ffffd5ab
kMIDIMessageSendErr    | -10838 | ffffd5aa
kMIDIServerStartErr    | -10839 | ffffd5a9
kMIDISetupFormatErr    | -10840 | ffffd5a8
kMIDIWrongThread       | -10841 | ffffd5a7
kMIDIObjectNotFound    | -10842 | ffffd5a6
kMIDIIDNotUnique       | -10843 | ffffd5a5
kMIDINotPermitted      | -10844 | ffffd5a4
kMIDIUnknownError      | -10845 | ffffd5a3

[stephenk]

Thanks for that great explanation. So, if I understand this correctly, ffffffce is -50? That’s not one of those CoreMIDI Errors…

[ed95]

https://www.osstatus.com/ is very useful for this. -50 is kAudio_ParamError from CoreAudio

[stephenk]

Thanks! Great link!