iOS 开发：以编程方式导航视频章节

Question

我想以编程方式导航 mp4 视频的章节。 这些章节在 QuickTime 中运行，所以我认为视频格式不是问题。

此页面中的代码应该返回一个章节数组，但只返回一个空数组： https://developer.apple.com/documentation/avfoundation/media_playback/presenting_chapter_markers

let asset = AVAsset(url: <# Asset URL #>)
let chapterLocalesKey = "availableChapterLocales"
 
asset.loadValuesAsynchronously(forKeys: [chapterLocalesKey]) {
    var error: NSError?
    let status = asset.statusOfValue(forKey: chapterLocalesKey, error: &error)
    if status == .loaded {
        let languages = Locale.preferredLanguages
        let chapterMetadata = asset.chapterMetadataGroups(bestMatchingPreferredLanguages: languages)
        // Process chapter metadata.
    }
    else {
        // Handle other status cases.
    }
}

有人知道怎么做吗？

Answer 1

func chapters(from avAsset: AVAsset) async -> [Chapter] {
    guard let locales = try? await avAsset.load(.availableChapterLocales) else { return [] }
    guard let locale = locales.first else { return [] }
    guard let groups = try? await avAsset.loadChapterMetadataGroups(withTitleLocale: locale, containingItemsWithCommonKeys: [.commonKeyArtwork]) else { return [] }
    
    return groups.map { group in
        let titleItems = AVMetadataItem.metadataItems(from: group.items, filteredByIdentifier: .commonIdentifierTitle)
        // Retrieve the artwork metadata items.
        let artworkItems = AVMetadataItem.metadataItems(from: group.items, filteredByIdentifier: .commonIdentifierArtwork)

        let title = titleItems.first?.stringValue ?? ""
        let thumbnailData = artworkItems.first?.dataValue

        return Chapter(cmTime: group.timeRange.start, title: title, thumbnailData: thumbnailData)
    }
}