如何使用本地视频文件在swift中创建缩略图?
例如,如果视频文件路径位于此处:
file:///Users/Dev/Library/Developer/CoreSimulator/Devices/F33222DF-D8F0-448B-A127-C5B03C64D0DC/data/Containers/Data/Application/4BC62DBF-0108-453C-9324-5BC0E356FE24/tmp/trim.059D11E6-F0EF-43DB-9E97-CA4F1F95D6B6.MOV
谢谢。
答案 0 :(得分:52)
通过以下编辑进行翻译:
First frame of a video using AVFoundation
var err: NSError? = nil
let asset = AVURLAsset(URL: NSURL(fileURLWithPath: "/that/long/path"), options: nil)
let imgGenerator = AVAssetImageGenerator(asset: asset)
let cgImage = imgGenerator.copyCGImageAtTime(CMTimeMake(0, 1), actualTime: nil, error: &err)
// !! check the error before proceeding
let uiImage = UIImage(CGImage: cgImage)
let imageView = UIImageView(image: uiImage)
// lay out this image view, or if it already exists, set its image property to uiImage
答案 1 :(得分:52)
BaseZen的答案翻译 Swift 3 / Swift 4
您需要将要制作缩略图的视频的位置设置为网址资源路径,例如:
别忘了import AVFoundation
func generateThumbnail(path: URL) -> UIImage? {
do {
let asset = AVURLAsset(url: path, options: nil)
let imgGenerator = AVAssetImageGenerator(asset: asset)
imgGenerator.appliesPreferredTrackTransform = true
let cgImage = try imgGenerator.copyCGImage(at: CMTimeMake(value: 0, timescale: 1), actualTime: nil)
let thumbnail = UIImage(cgImage: cgImage)
return thumbnail
} catch let error {
print("*** Error generating thumbnail: \(error.localizedDescription)")
return nil
}
}
对于遇到此问题的每个人,我在Github
上托管的示例中创建了以下内容答案 2 :(得分:19)
这是David的答案的清理版本,并针对iOS 11 / Swift 4.x进行了测试。
请注意根据您使用的Swift版本处理初始时间的不同调用。
func generateThumbnail(url: URL) -> UIImage? {
do {
let asset = AVURLAsset(url: url)
let imageGenerator = AVAssetImageGenerator(asset: asset)
imageGenerator.appliesPreferredTrackTransform = true
// Select the right one based on which version you are using
// Swift 4.2
let cgImage = try imageGenerator.copyCGImage(at: .zero,
actualTime: nil)
// Swift 4.0
let cgImage = try imageGenerator.copyCGImage(at: kCMTimeZero,
actualTime: nil)
return UIImage(cgImage: cgImage)
} catch {
print(error.localizedDescription)
return nil
}
}
AVURLAsset
URL
AVAssetImageGenerator
创建AVURLAsset
,负责制作缩略图CGImage
UIImage
。退货答案 3 :(得分:12)
BaseZen的答案翻译成Swift 2:
import UIKit
import AVFoundation
do {
let asset = AVURLAsset(URL: NSURL(fileURLWithPath: "/that/long/path"), options: nil)
let imgGenerator = AVAssetImageGenerator(asset: asset)
imgGenerator.appliesPreferredTrackTransform = true
let cgImage = try imgGenerator.copyCGImageAtTime(CMTimeMake(0, 1), actualTime: nil)
let uiImage = UIImage(CGImage: cgImage)
let imageView = UIImageView(image: uiImage)
// lay out this image view, or if it already exists, set its image property to uiImage
} catch let error as NSError {
print("Error generating thumbnail: \(error)")
}
答案 4 :(得分:4)
编写较少且简单的代码以便理解会更好。 这就是我在Swift中转换解决方案(3.1 ... 4.2)
import AVFoundation
func videoPreviewUIImage(moviePath: URL) -> UIImage? {
let asset = AVURLAsset(url: moviePath)
let generator = AVAssetImageGenerator(asset: asset)
generator.appliesPreferredTrackTransform = true
let timestamp = CMTime(seconds: 2, preferredTimescale: 60)
if let imageRef = try? generator.copyCGImage(at: timestamp, actualTime: nil) {
return UIImage(cgImage: imageRef)
} else {
return nil
}
}
希望它会对某人有所帮助。
答案 5 :(得分:0)
Swift 5.3
作为其他答案的替代方法,我稍加修改后决定进行URL扩展。
import AVFoundation
extension URL {
func generateThumbnail() -> UIImage? {
do {
let asset = AVURLAsset(url: self)
let imageGenerator = AVAssetImageGenerator(asset: asset)
imageGenerator.appliesPreferredTrackTransform = true
// Swift 5.3
let cgImage = try imageGenerator.copyCGImage(at: .zero,
actualTime: nil)
return UIImage(cgImage: cgImage)
} catch {
print(error.localizedDescription)
return nil
}
}
}
用法:
let image = someURL.generateThumbnail()
答案 6 :(得分:-1)
func saveImageDocumentDirectoryWithDate(tempImage:UIImage, block : @escaping (_ url: URL?) -> Void ){
let documentsDirectoryURL = try! FileManager().url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: true)
let random : String = randomString(length: 5)
let fileURL = documentsDirectoryURL.appendingPathComponent(String(format:"CPImage%@.png",random))
do { try tempImage.pngData()?.write(to: fileURL) }
catch { block(nil) }
block(fileURL)}