Getting video file type formats from UTI's

Question

I'm building a video editing application that uses AVFoundation. When the user goes to import their video (via an NSOpenPanel file browser), I only want to allow them to select acceptable video formats that AVFoundation supports.

You can retrieve those accepted formats by calling audioVisualTypes() on AVURLAsset. However, these formats include a lot of gibberish / stuff I don't need, ex:

 "public.mpeg",


    "dyn.ah62d46dzqm0gw23sqf40k4pts3y1g7pbru00g55ssvw067b4gq81q4peqz1w88brrz2de7a",
        "public.dv-movie",
        "public.pls-playlist",

"dyn.ah62d46dzqm0gw23sqf40k4pts3y1g7pbru00g55ssvw067b4gq80c6durvy0g2pyrf106p50r3wc62pusb0gnpxrsbw0s7pwru",
    "public.aac-audio",

Does anyone have an idea of how to parse these into a simple array of file extensions? Thanks

Answer 1

You want to use the function UTTypeCopyPreferredTagWithClass. Try this in a playground

import MobileCoreServices
import AVFoundation

let avTypes = AVURLAsset.audiovisualTypes()

let anAVType = avTypes[0]

if let ext = UTTypeCopyPreferredTagWithClass(anAVType as CFString,kUTTagClassFilenameExtension)?.takeRetainedValue() {
    print("The AVType \(anAVType) has extension '\(ext)'")
}
else {
    print("Can't find the extension for the AVType '\(anAVType)")
}

print("\n")

let avExtensions = avTypes.map({UTTypeCopyPreferredTagWithClass($0 as CFString,kUTTagClassFilenameExtension)?.takeRetainedValue() as String? ?? ""})

print("All extensions = \(avExtensions)\n")

avExtensions = avExtensions.filter { $0.isEmpty == false }

print("All extensions filtered = \(avExtensions)\n")

print("First extension = '\(avExtensions[0])'")
print("Second extension = '\(avExtensions[1])'")
print("Third extension = '\(avExtensions[2])'")

Result:

The AVType AVFileType(_rawValue: public.pls-playlist) has extension 'pls'


All extensions = ["pls", "", "aifc", "m4r", "", "", "wav", "", "", "3gp", "3g2", "", "", "", "flac", "avi", "m2a", "", "aa", "", "aac", "mpa", "", "", "", "", "", "m3u", "mov", "aiff", "ttml", "", "m4v", "", "", "amr", "caf", "m4a", "mp4", "mp1", "", "m1a", "mp4", "mp2", "mp3", "itt", "au", "eac3", "", "", "webvtt", "", "", "vtt", "ac3", "m4p", "", "", "mqv"]

All extensions filtered = ["pls", "aifc", "m4r", "wav", "3gp", "3g2", "flac", "avi", "m2a", "aa", "aac", "mpa", "m3u", "mov", "aiff", "ttml", "m4v", "amr", "caf", "m4a", "mp4", "mp1", "m1a", "mp4", "mp2", "mp3", "itt", "au", "eac3", "webvtt", "vtt", "ac3", "m4p", "mqv"]

First extension = 'pls'
Second extension = 'aifc'
Third extension = 'm4r'