从 UTI 获取视频文件类型格式答案

【问题标题】：Getting video file type formats from UTI's从 UTI 获取视频文件类型格式
【发布时间】：2018-01-05 19:04:36
【问题描述】：

我正在构建一个使用AVFoundation 的视频编辑应用程序。当用户导入他们的视频时（通过NSOpenPanel 文件浏览器），我只想让他们选择AVFoundation 支持的可接受的视频格式。

您可以通过在 AVURLAsset 上调用 audioVisualTypes() 来检索那些接受的格式。但是，这些格式包含很多我不需要的乱码/东西，例如：

 "public.mpeg",


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

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

有没有人知道如何将这些解析为一个简单的文件扩展名数组？谢谢

【问题讨论】：

标签： ios macos avfoundation

【解决方案1】：

您想使用函数 UTTypeCopyPreferredTagWithClass。在操场上试试这个

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])'")

结果：

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'

【讨论】：