如何将UIImage数组导出为电影？-Java 学习之路

176

我有一个严重的问题：我有 NSArray 有几个 UIImage 对象 . 我现在想做的是从那些 UIImages 创建电影 . 但我不知道该怎么做 .

我希望有人可以帮助我或给我一个代码片段，它可以做我喜欢的事情 .

Edit: 供将来参考 - 应用解决方案后，如果视频看起来失真，请确保您捕获的图像/区域的宽度是16的倍数 . 经过多个小时的努力后发现：
Why does my movie from UIImages gets distorted?

这是完整的解决方案（只需确保宽度为16的倍数）
http://codethink.no-ip.org/wordpress/archives/673

9 回答

209

看看AVAssetWriter以及AVFoundation framework的其余部分 . 编写器有一个AVAssetWriterInput类型的输入，后者又有一个名为appendSampleBuffer:的方法，可以将单个帧添加到视频流中 . 基本上你必须：

1) Wire the writer:

NSError *error = nil;
AVAssetWriter *videoWriter = [[AVAssetWriter alloc] initWithURL:
    [NSURL fileURLWithPath:somePath] fileType:AVFileTypeQuickTimeMovie
    error:&error];
NSParameterAssert(videoWriter);

NSDictionary *videoSettings = [NSDictionary dictionaryWithObjectsAndKeys:
    AVVideoCodecH264, AVVideoCodecKey,
    [NSNumber numberWithInt:640], AVVideoWidthKey,
    [NSNumber numberWithInt:480], AVVideoHeightKey,
    nil];
AVAssetWriterInput* writerInput = [[AVAssetWriterInput
    assetWriterInputWithMediaType:AVMediaTypeVideo
    outputSettings:videoSettings] retain]; //retain should be removed if ARC

NSParameterAssert(writerInput);
NSParameterAssert([videoWriter canAddInput:writerInput]);
[videoWriter addInput:writerInput];

2) Start a session:

[videoWriter startWriting];
[videoWriter startSessionAtSourceTime:…] //use kCMTimeZero if unsure

3) Write some samples:

// Or you can use AVAssetWriterInputPixelBufferAdaptor.
// That lets you feed the writer input data from a CVPixelBuffer
// that’s quite easy to create from a CGImage.
[writerInput appendSampleBuffer:sampleBuffer];

4) Finish the session:

[writerInput markAsFinished];
[videoWriter endSessionAtSourceTime:…]; //optional can call finishWriting without specifiying endTime
[videoWriter finishWriting]; //deprecated in ios6
/*
[videoWriter finishWritingWithCompletionHandler:...]; //ios 6.0+
*/

你仍然需要填写很多空白，但我认为唯一真正困难的部分是从 CGImage 获取一个像素缓冲区：

- (CVPixelBufferRef) newPixelBufferFromCGImage: (CGImageRef) image
{
    NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:
        [NSNumber numberWithBool:YES], kCVPixelBufferCGImageCompatibilityKey,
        [NSNumber numberWithBool:YES], kCVPixelBufferCGBitmapContextCompatibilityKey,
        nil];
    CVPixelBufferRef pxbuffer = NULL;
    CVReturn status = CVPixelBufferCreate(kCFAllocatorDefault, frameSize.width,
        frameSize.height, kCVPixelFormatType_32ARGB, (CFDictionaryRef) options, 
        &pxbuffer);
    NSParameterAssert(status == kCVReturnSuccess && pxbuffer != NULL);

    CVPixelBufferLockBaseAddress(pxbuffer, 0);
    void *pxdata = CVPixelBufferGetBaseAddress(pxbuffer);
    NSParameterAssert(pxdata != NULL);

    CGColorSpaceRef rgbColorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef context = CGBitmapContextCreate(pxdata, frameSize.width,
        frameSize.height, 8, 4*frameSize.width, rgbColorSpace, 
        kCGImageAlphaNoneSkipFirst);
    NSParameterAssert(context);
    CGContextConcatCTM(context, frameTransform);
    CGContextDrawImage(context, CGRectMake(0, 0, CGImageGetWidth(image), 
        CGImageGetHeight(image)), image);
    CGColorSpaceRelease(rgbColorSpace);
    CGContextRelease(context);

    CVPixelBufferUnlockBaseAddress(pxbuffer, 0);

    return pxbuffer;
}

frameSize 是描述目标帧大小的 CGSize ，而 frameTransform 是 CGAffineTransform ，可让您在将图像绘制到帧中时对其进行变换 .

回复于 2024-04-29T18:49:31+08:00

Here is the latest working code on iOS8 in Objective-C.

我们不得不对@ Zoul上面的答案进行各种调整，以使其适用于最新版本的Xcode和iOS8 . 这是我们的完整工作代码，它采用一组UIImages，将它们转换为.mov文件，将其保存到临时目录，然后将其移动到相机胶卷 . 我们汇集了来自多个不同帖子的代码以实现这一目标 . 我们已经强调了我们必须解决的陷阱，以便在我们的评论中使用代码 .

(1) Create a collection of UIImages

[self saveMovieToLibrary]


- (IBAction)saveMovieToLibrary
{
    // You just need the height and width of the video here
    // For us, our input and output video was 640 height x 480 width
    // which is what we get from the iOS front camera
    ATHSingleton *singleton = [ATHSingleton singletons];
    int height = singleton.screenHeight;
    int width = singleton.screenWidth;

    // You can save a .mov or a .mp4 file        
    //NSString *fileNameOut = @"temp.mp4";
    NSString *fileNameOut = @"temp.mov";

    // We chose to save in the tmp/ directory on the device initially
    NSString *directoryOut = @"tmp/";
    NSString *outFile = [NSString stringWithFormat:@"%@%@",directoryOut,fileNameOut];
    NSString *path = [NSHomeDirectory() stringByAppendingPathComponent:[NSString stringWithFormat:outFile]];
    NSURL *videoTempURL = [NSURL fileURLWithPath:[NSString stringWithFormat:@"%@%@", NSTemporaryDirectory(), fileNameOut]];

    // WARNING: AVAssetWriter does not overwrite files for us, so remove the destination file if it already exists
    NSFileManager *fileManager = [NSFileManager defaultManager];
    [fileManager removeItemAtPath:[videoTempURL path]  error:NULL];


    // Create your own array of UIImages        
    NSMutableArray *images = [NSMutableArray array];
    for (int i=0; i<singleton.numberOfScreenshots; i++)
    {
        // This was our routine that returned a UIImage. Just use your own.
        UIImage *image =[self uiimageFromCopyOfPixelBuffersUsingIndex:i];
        // We used a routine to write text onto every image 
        // so we could validate the images were actually being written when testing. This was it below. 
        image = [self writeToImage:image Text:[NSString stringWithFormat:@"%i",i ]];
        [images addObject:image];     
    }

// If you just want to manually add a few images - here is code you can uncomment
// NSString *path = [NSHomeDirectory() stringByAppendingPathComponent:[NSString stringWithFormat:@"Documents/movie.mp4"]];
//    NSArray *images = [[NSArray alloc] initWithObjects:
//                      [UIImage imageNamed:@"add_ar.png"],
//                      [UIImage imageNamed:@"add_ja.png"],
//                      [UIImage imageNamed:@"add_ru.png"],
//                      [UIImage imageNamed:@"add_ru.png"],
//                      [UIImage imageNamed:@"add_ar.png"],
//                      [UIImage imageNamed:@"add_ja.png"],
//                      [UIImage imageNamed:@"add_ru.png"],
//                      [UIImage imageNamed:@"add_ar.png"],
//                      [UIImage imageNamed:@"add_en.png"], nil];



    [self writeImageAsMovie:images toPath:path size:CGSizeMake(height, width)];
}

这是创建AssetWriter并向其添加图像以进行写入的主要方法 .

(2) Wire up an AVAssetWriter

-(void)writeImageAsMovie:(NSArray *)array toPath:(NSString*)path size:(CGSize)size
{

    NSError *error = nil;

    // FIRST, start up an AVAssetWriter instance to write your video
    // Give it a destination path (for us: tmp/temp.mov)
    AVAssetWriter *videoWriter = [[AVAssetWriter alloc] initWithURL:[NSURL fileURLWithPath:path]
                                                           fileType:AVFileTypeQuickTimeMovie
                                                              error:&error];


    NSParameterAssert(videoWriter);

    NSDictionary *videoSettings = [NSDictionary dictionaryWithObjectsAndKeys:
                                   AVVideoCodecH264, AVVideoCodecKey,
                                   [NSNumber numberWithInt:size.width], AVVideoWidthKey,
                                   [NSNumber numberWithInt:size.height], AVVideoHeightKey,
                                   nil];

    AVAssetWriterInput* writerInput = [AVAssetWriterInput assetWriterInputWithMediaType:AVMediaTypeVideo
                                                                         outputSettings:videoSettings];

    AVAssetWriterInputPixelBufferAdaptor *adaptor = [AVAssetWriterInputPixelBufferAdaptor assetWriterInputPixelBufferAdaptorWithAssetWriterInput:writerInput
                                                                                                                     sourcePixelBufferAttributes:nil];
    NSParameterAssert(writerInput);
    NSParameterAssert([videoWriter canAddInput:writerInput]);
    [videoWriter addInput:writerInput];

(3) Start a writing Session （注意：方法从上面继续）

//Start a SESSION of writing. 
    // After you start a session, you will keep adding image frames 
    // until you are complete - then you will tell it you are done.
    [videoWriter startWriting];
    // This starts your video at time = 0
    [videoWriter startSessionAtSourceTime:kCMTimeZero];

    CVPixelBufferRef buffer = NULL;

    // This was just our utility class to get screen sizes etc.    
    ATHSingleton *singleton = [ATHSingleton singletons];

    int i = 0;
    while (1)
    {
        // Check if the writer is ready for more data, if not, just wait
        if(writerInput.readyForMoreMediaData){

            CMTime frameTime = CMTimeMake(150, 600);
            // CMTime = Value and Timescale.
            // Timescale = the number of tics per second you want
            // Value is the number of tics
            // For us - each frame we add will be 1/4th of a second
            // Apple recommend 600 tics per second for video because it is a 
            // multiple of the standard video rates 24, 30, 60 fps etc.
            CMTime lastTime=CMTimeMake(i*150, 600);
            CMTime presentTime=CMTimeAdd(lastTime, frameTime);

            if (i == 0) {presentTime = CMTimeMake(0, 600);} 
            // This ensures the first frame starts at 0.


            if (i >= [array count])
            {
                buffer = NULL;
            }
            else
            {
                // This command grabs the next UIImage and converts it to a CGImage
                buffer = [self pixelBufferFromCGImage:[[array objectAtIndex:i] CGImage]];
            }


            if (buffer)
            {
                // Give the CGImage to the AVAssetWriter to add to your video
                [adaptor appendPixelBuffer:buffer withPresentationTime:presentTime];
                i++;
            }
            else
            {

(4) Finish the Session （注：方法从上面继续）

//Finish the session:
                // This is important to be done exactly in this order
                [writerInput markAsFinished];
                // WARNING: finishWriting in the solution above is deprecated. 
                // You now need to give a completion handler.
                [videoWriter finishWritingWithCompletionHandler:^{
                    NSLog(@"Finished writing...checking completion status...");
                    if (videoWriter.status != AVAssetWriterStatusFailed && videoWriter.status == AVAssetWriterStatusCompleted)
                    {
                        NSLog(@"Video writing succeeded.");

                        // Move video to camera roll
                        // NOTE: You cannot write directly to the camera roll. 
                        // You must first write to an iOS directory then move it!
                        NSURL *videoTempURL = [NSURL fileURLWithPath:[NSString stringWithFormat:@"%@", path]];
                        [self saveToCameraRoll:videoTempURL];

                    } else
                    {
                        NSLog(@"Video writing failed: %@", videoWriter.error);
                    }

                }]; // end videoWriter finishWriting Block

                CVPixelBufferPoolRelease(adaptor.pixelBufferPool);

                NSLog (@"Done");
                break;
            }
        }
    }    
}

(5) Convert your UIImages to a CVPixelBufferRef
此方法将为您提供AssetWriter所需的CV像素缓冲区引用 . 这是从您从UIImage（上图）获得的CGImageRef获得的 .

- (CVPixelBufferRef) pixelBufferFromCGImage: (CGImageRef) image
{
    // This again was just our utility class for the height & width of the
    // incoming video (640 height x 480 width)
    ATHSingleton *singleton = [ATHSingleton singletons];
    int height = singleton.screenHeight;
    int width = singleton.screenWidth;

    NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:
                             [NSNumber numberWithBool:YES], kCVPixelBufferCGImageCompatibilityKey,
                             [NSNumber numberWithBool:YES], kCVPixelBufferCGBitmapContextCompatibilityKey,
                             nil];
    CVPixelBufferRef pxbuffer = NULL;

    CVReturn status = CVPixelBufferCreate(kCFAllocatorDefault, width,
                                          height, kCVPixelFormatType_32ARGB, (__bridge CFDictionaryRef) options,
                                          &pxbuffer);

    NSParameterAssert(status == kCVReturnSuccess && pxbuffer != NULL);

    CVPixelBufferLockBaseAddress(pxbuffer, 0);
    void *pxdata = CVPixelBufferGetBaseAddress(pxbuffer);
    NSParameterAssert(pxdata != NULL);

    CGColorSpaceRef rgbColorSpace = CGColorSpaceCreateDeviceRGB();

    CGContextRef context = CGBitmapContextCreate(pxdata, width,
                                                 height, 8, 4*width, rgbColorSpace,
                                                 kCGImageAlphaNoneSkipFirst);
    NSParameterAssert(context);
    CGContextConcatCTM(context, CGAffineTransformMakeRotation(0));
    CGContextDrawImage(context, CGRectMake(0, 0, CGImageGetWidth(image),
                                           CGImageGetHeight(image)), image);
    CGColorSpaceRelease(rgbColorSpace);
    CGContextRelease(context);

    CVPixelBufferUnlockBaseAddress(pxbuffer, 0);

    return pxbuffer;
}

(6) Move Your Video to the Camera Roll 由于AVAssetWriter无法直接写入相机胶卷，因此会将视频从"tmp/temp.mov"（或您上面命名的任何文件名）移动到相机胶卷 .

- (void) saveToCameraRoll:(NSURL *)srcURL
{
    NSLog(@"srcURL: %@", srcURL);

    ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
    ALAssetsLibraryWriteVideoCompletionBlock videoWriteCompletionBlock =
    ^(NSURL *newURL, NSError *error) {
        if (error) {
            NSLog( @"Error writing image with metadata to Photo Library: %@", error );
        } else {
            NSLog( @"Wrote image with metadata to Photo Library %@", newURL.absoluteString);
        }
    };

    if ([library videoAtPathIsCompatibleWithSavedPhotosAlbum:srcURL])
    {
        [library writeVideoAtPathToSavedPhotosAlbum:srcURL
                                    completionBlock:videoWriteCompletionBlock];
    }
}

Zoul上面的答案给出了你将要做的很好的概述 . 我们广泛地评论了这段代码，以便您可以看到它是如何使用工作代码完成的 .

回复于 2024-04-29T18:49:31+08:00

-5

NOTE: This is a Swift 2.1 solution (iOS8+, XCode 7.2) .

上周我开始编写iOS代码来生成图像视频 . 我有一点AVFoundation经验，但从未听说过CVPixelBuffer . 我在这个页面上看到了答案，也是here . 花了好几天的时间来剖析一切，并以一种对我的大脑有意义的方式将它们全部重新组合在Swift中 . 以下是我提出的建议 .

注意：如果您将下面的所有代码复制/粘贴到单个Swift文件中，它应该编译 . 你只需要调整 loadImages() 和 RenderSettings 值 .

第1部分：进行设置

在这里，我将所有与导出相关的设置分组到一个 RenderSettings 结构中 .

import AVFoundation
import UIKit
import Photos

struct RenderSettings {

    var width: CGFloat = 1280
    var height: CGFloat = 720
    var fps: Int32 = 2   // 2 frames per second
    var avCodecKey = AVVideoCodecH264
    var videoFilename = "render"
    var videoFilenameExt = "mp4"

    var size: CGSize {
        return CGSize(width: width, height: height)
    }

    var outputURL: NSURL {
        // Use the CachesDirectory so the rendered video file sticks around as long as we need it to.
        // Using the CachesDirectory ensures the file won't be included in a backup of the app.
        let fileManager = NSFileManager.defaultManager()
        if let tmpDirURL = try? fileManager.URLForDirectory(.CachesDirectory, inDomain: .UserDomainMask, appropriateForURL: nil, create: true) {
            return tmpDirURL.URLByAppendingPathComponent(videoFilename).URLByAppendingPathExtension(videoFilenameExt)
        }
        fatalError("URLForDirectory() failed")
    }
}

第2部分：ImageAnimator

ImageAnimator 类了解您的图像并使用 VideoWriter 类来执行渲染 . 这个想法是将视频内容代码与低级AVFoundation代码分开 . 我还在这里添加了 saveToLibrary() 作为类函数，它在链的末尾被调用以将视频保存到照片库 .

class ImageAnimator {

    // Apple suggests a timescale of 600 because it's a multiple of standard video rates 24, 25, 30, 60 fps etc.
    static let kTimescale: Int32 = 600

    let settings: RenderSettings
    let videoWriter: VideoWriter
    var images: [UIImage]!

    var frameNum = 0

    class func saveToLibrary(videoURL: NSURL) {
        PHPhotoLibrary.requestAuthorization { status in
            guard status == .Authorized else { return }

            PHPhotoLibrary.sharedPhotoLibrary().performChanges({
                PHAssetChangeRequest.creationRequestForAssetFromVideoAtFileURL(videoURL)
                }) { success, error in
                    if !success {
                        print("Could not save video to photo library:", error)
                    }
            }
        }
    }

    class func removeFileAtURL(fileURL: NSURL) {
        do {
            try NSFileManager.defaultManager().removeItemAtPath(fileURL.path!)
        }
        catch _ as NSError {
            // Assume file doesn't exist.
        }
    }

    init(renderSettings: RenderSettings) {
        settings = renderSettings
        videoWriter = VideoWriter(renderSettings: settings)
        images = loadImages()
    }

    func render(completion: ()->Void) {

        // The VideoWriter will fail if a file exists at the URL, so clear it out first.
        ImageAnimator.removeFileAtURL(settings.outputURL)

        videoWriter.start()
        videoWriter.render(appendPixelBuffers) {
            ImageAnimator.saveToLibrary(self.settings.outputURL)
            completion()
        }

    }

    // Replace this logic with your own.
    func loadImages() -> [UIImage] {
        var images = [UIImage]()
        for index in 1...10 {
            let filename = "\(index).jpg"
            images.append(UIImage(named: filename)!)
        }
        return images
    }

    // This is the callback function for VideoWriter.render()
    func appendPixelBuffers(writer: VideoWriter) -> Bool {

        let frameDuration = CMTimeMake(Int64(ImageAnimator.kTimescale / settings.fps), ImageAnimator.kTimescale)

        while !images.isEmpty {

            if writer.isReadyForData == false {
                // Inform writer we have more buffers to write.
                return false
            }

            let image = images.removeFirst()
            let presentationTime = CMTimeMultiply(frameDuration, Int32(frameNum))
            let success = videoWriter.addImage(image, withPresentationTime: presentationTime)
            if success == false {
                fatalError("addImage() failed")
            }

            frameNum++
        }

        // Inform writer all buffers have been written.
        return true
    }

}

第3部分：VideoWriter

VideoWriter 类完成了所有AVFoundation的繁重工作 . 它主要是 AVAssetWriter 和 AVAssetWriterInput 的包装 . 它还包含由我编写的花哨代码，它知道如何将图像转换为 CVPixelBuffer .

class VideoWriter {

    let renderSettings: RenderSettings

    var videoWriter: AVAssetWriter!
    var videoWriterInput: AVAssetWriterInput!
    var pixelBufferAdaptor: AVAssetWriterInputPixelBufferAdaptor!

    var isReadyForData: Bool {
        return videoWriterInput?.readyForMoreMediaData ?? false
    }

    class func pixelBufferFromImage(image: UIImage, pixelBufferPool: CVPixelBufferPool, size: CGSize) -> CVPixelBuffer {

        var pixelBufferOut: CVPixelBuffer?

        let status = CVPixelBufferPoolCreatePixelBuffer(kCFAllocatorDefault, pixelBufferPool, &pixelBufferOut)
        if status != kCVReturnSuccess {
            fatalError("CVPixelBufferPoolCreatePixelBuffer() failed")
        }

        let pixelBuffer = pixelBufferOut!

        CVPixelBufferLockBaseAddress(pixelBuffer, 0)

        let data = CVPixelBufferGetBaseAddress(pixelBuffer)
        let rgbColorSpace = CGColorSpaceCreateDeviceRGB()
        let context = CGBitmapContextCreate(data, Int(size.width), Int(size.height),
            8, CVPixelBufferGetBytesPerRow(pixelBuffer), rgbColorSpace, CGImageAlphaInfo.PremultipliedFirst.rawValue)

        CGContextClearRect(context, CGRectMake(0, 0, size.width, size.height))

        let horizontalRatio = size.width / image.size.width
        let verticalRatio = size.height / image.size.height
        //aspectRatio = max(horizontalRatio, verticalRatio) // ScaleAspectFill
        let aspectRatio = min(horizontalRatio, verticalRatio) // ScaleAspectFit

        let newSize = CGSize(width: image.size.width * aspectRatio, height: image.size.height * aspectRatio)

        let x = newSize.width < size.width ? (size.width - newSize.width) / 2 : 0
        let y = newSize.height < size.height ? (size.height - newSize.height) / 2 : 0

        CGContextDrawImage(context, CGRectMake(x, y, newSize.width, newSize.height), image.CGImage)
        CVPixelBufferUnlockBaseAddress(pixelBuffer, 0)

        return pixelBuffer
    }

    init(renderSettings: RenderSettings) {
        self.renderSettings = renderSettings
    }

    func start() {

        let avOutputSettings: [String: AnyObject] = [
            AVVideoCodecKey: renderSettings.avCodecKey,
            AVVideoWidthKey: NSNumber(float: Float(renderSettings.width)),
            AVVideoHeightKey: NSNumber(float: Float(renderSettings.height))
        ]

        func createPixelBufferAdaptor() {
            let sourcePixelBufferAttributesDictionary = [
                kCVPixelBufferPixelFormatTypeKey as String: NSNumber(unsignedInt: kCVPixelFormatType_32ARGB),
                kCVPixelBufferWidthKey as String: NSNumber(float: Float(renderSettings.width)),
                kCVPixelBufferHeightKey as String: NSNumber(float: Float(renderSettings.height))
            ]
            pixelBufferAdaptor = AVAssetWriterInputPixelBufferAdaptor(assetWriterInput: videoWriterInput,
                sourcePixelBufferAttributes: sourcePixelBufferAttributesDictionary)
        }

        func createAssetWriter(outputURL: NSURL) -> AVAssetWriter {
            guard let assetWriter = try? AVAssetWriter(URL: outputURL, fileType: AVFileTypeMPEG4) else {
                fatalError("AVAssetWriter() failed")
            }

            guard assetWriter.canApplyOutputSettings(avOutputSettings, forMediaType: AVMediaTypeVideo) else {
                fatalError("canApplyOutputSettings() failed")
            }

            return assetWriter
        }

        videoWriter = createAssetWriter(renderSettings.outputURL)
        videoWriterInput = AVAssetWriterInput(mediaType: AVMediaTypeVideo, outputSettings: avOutputSettings)

        if videoWriter.canAddInput(videoWriterInput) {
            videoWriter.addInput(videoWriterInput)
        }
        else {
            fatalError("canAddInput() returned false")
        }

        // The pixel buffer adaptor must be created before we start writing.
        createPixelBufferAdaptor()

        if videoWriter.startWriting() == false {
            fatalError("startWriting() failed")
        }

        videoWriter.startSessionAtSourceTime(kCMTimeZero)

        precondition(pixelBufferAdaptor.pixelBufferPool != nil, "nil pixelBufferPool")
    }

    func render(appendPixelBuffers: (VideoWriter)->Bool, completion: ()->Void) {

        precondition(videoWriter != nil, "Call start() to initialze the writer")

        let queue = dispatch_queue_create("mediaInputQueue", nil)
        videoWriterInput.requestMediaDataWhenReadyOnQueue(queue) {
            let isFinished = appendPixelBuffers(self)
            if isFinished {
                self.videoWriterInput.markAsFinished()
                self.videoWriter.finishWritingWithCompletionHandler() {
                    dispatch_async(dispatch_get_main_queue()) {
                        completion()
                    }
                }
            }
            else {
                // Fall through. The closure will be called again when the writer is ready.
            }
        }
    }

    func addImage(image: UIImage, withPresentationTime presentationTime: CMTime) -> Bool {

        precondition(pixelBufferAdaptor != nil, "Call start() to initialze the writer")

        let pixelBuffer = VideoWriter.pixelBufferFromImage(image, pixelBufferPool: pixelBufferAdaptor.pixelBufferPool!, size: renderSettings.size)
        return pixelBufferAdaptor.appendPixelBuffer(pixelBuffer, withPresentationTime: presentationTime)
    }

}

第4部分：实现目标

一切就绪后，这些是你的3条魔术线：

let settings = RenderSettings()
let imageAnimator = ImageAnimator(renderSettings: settings)
imageAnimator.render() {
    print("yes")
}

回复于 2024-04-29T18:49:31+08:00

37

我采用了Zoul的主要思想，并整合了AVAssetWriterInputPixelBufferAdaptor方法，并开始构建一些小框架 .

随意检查并改进它！ CEMovieMaker

回复于 2024-04-29T18:49:31+08:00

这是在iOS 8上测试的Swift 2.x版本 . 它结合了来自@Scott Raposa和@Praxiteles的答案以及来自@acj的代码，为另一个问题做出了贡献 . 来自@acj的代码在这里：https://gist.github.com/acj/6ae90aa1ebb8cad6b47b . @TimBull也提供了代码 .

就像@Scott Raposa一样，我从来没有听说过 CVPixelBufferPoolCreatePixelBuffer 和其他几个功能，更不用说了解如何使用它们 .

您在下面看到的内容主要是通过反复试验和阅读Apple文档拼凑而成 . 请谨慎使用，并在出现错误时提供建议 .

用法：

import UIKit
import AVFoundation
import Photos

writeImagesAsMovie(yourImages, videoPath: yourPath, videoSize: yourSize, videoFPS: 30)

码：

func writeImagesAsMovie(allImages: [UIImage], videoPath: String, videoSize: CGSize, videoFPS: Int32) {
    // Create AVAssetWriter to write video
    guard let assetWriter = createAssetWriter(videoPath, size: videoSize) else {
        print("Error converting images to video: AVAssetWriter not created")
        return
    }

    // If here, AVAssetWriter exists so create AVAssetWriterInputPixelBufferAdaptor
    let writerInput = assetWriter.inputs.filter{ $0.mediaType == AVMediaTypeVideo }.first!
    let sourceBufferAttributes : [String : AnyObject] = [
        kCVPixelBufferPixelFormatTypeKey as String : Int(kCVPixelFormatType_32ARGB),
        kCVPixelBufferWidthKey as String : videoSize.width,
        kCVPixelBufferHeightKey as String : videoSize.height,
        ]
    let pixelBufferAdaptor = AVAssetWriterInputPixelBufferAdaptor(assetWriterInput: writerInput, sourcePixelBufferAttributes: sourceBufferAttributes)

    // Start writing session
    assetWriter.startWriting()
    assetWriter.startSessionAtSourceTime(kCMTimeZero)
    if (pixelBufferAdaptor.pixelBufferPool == nil) {
        print("Error converting images to video: pixelBufferPool nil after starting session")
        return
    }

    // -- Create queue for <requestMediaDataWhenReadyOnQueue>
    let mediaQueue = dispatch_queue_create("mediaInputQueue", nil)

    // -- Set video parameters
    let frameDuration = CMTimeMake(1, videoFPS)
    var frameCount = 0

    // -- Add images to video
    let numImages = allImages.count
    writerInput.requestMediaDataWhenReadyOnQueue(mediaQueue, usingBlock: { () -> Void in
        // Append unadded images to video but only while input ready
        while (writerInput.readyForMoreMediaData && frameCount < numImages) {
            let lastFrameTime = CMTimeMake(Int64(frameCount), videoFPS)
            let presentationTime = frameCount == 0 ? lastFrameTime : CMTimeAdd(lastFrameTime, frameDuration)

            if !self.appendPixelBufferForImageAtURL(allImages[frameCount], pixelBufferAdaptor: pixelBufferAdaptor, presentationTime: presentationTime) {
                print("Error converting images to video: AVAssetWriterInputPixelBufferAdapter failed to append pixel buffer")
                return
            }

            frameCount += 1
        }

        // No more images to add? End video.
        if (frameCount >= numImages) {
            writerInput.markAsFinished()
            assetWriter.finishWritingWithCompletionHandler {
                if (assetWriter.error != nil) {
                    print("Error converting images to video: \(assetWriter.error)")
                } else {
                    self.saveVideoToLibrary(NSURL(fileURLWithPath: videoPath))
                    print("Converted images to movie @ \(videoPath)")
                }
            }
        }
    })
}


func createAssetWriter(path: String, size: CGSize) -> AVAssetWriter? {
    // Convert <path> to NSURL object
    let pathURL = NSURL(fileURLWithPath: path)

    // Return new asset writer or nil
    do {
        // Create asset writer
        let newWriter = try AVAssetWriter(URL: pathURL, fileType: AVFileTypeMPEG4)

        // Define settings for video input
        let videoSettings: [String : AnyObject] = [
            AVVideoCodecKey  : AVVideoCodecH264,
            AVVideoWidthKey  : size.width,
            AVVideoHeightKey : size.height,
            ]

        // Add video input to writer
        let assetWriterVideoInput = AVAssetWriterInput(mediaType: AVMediaTypeVideo, outputSettings: videoSettings)
        newWriter.addInput(assetWriterVideoInput)

        // Return writer
        print("Created asset writer for \(size.width)x\(size.height) video")
        return newWriter
    } catch {
        print("Error creating asset writer: \(error)")
        return nil
    }
}


func appendPixelBufferForImageAtURL(image: UIImage, pixelBufferAdaptor: AVAssetWriterInputPixelBufferAdaptor, presentationTime: CMTime) -> Bool {
    var appendSucceeded = false

    autoreleasepool {
        if  let pixelBufferPool = pixelBufferAdaptor.pixelBufferPool {
            let pixelBufferPointer = UnsafeMutablePointer<CVPixelBuffer?>.alloc(1)
            let status: CVReturn = CVPixelBufferPoolCreatePixelBuffer(
                kCFAllocatorDefault,
                pixelBufferPool,
                pixelBufferPointer
            )

            if let pixelBuffer = pixelBufferPointer.memory where status == 0 {
                fillPixelBufferFromImage(image, pixelBuffer: pixelBuffer)
                appendSucceeded = pixelBufferAdaptor.appendPixelBuffer(pixelBuffer, withPresentationTime: presentationTime)
                pixelBufferPointer.destroy()
            } else {
                NSLog("Error: Failed to allocate pixel buffer from pool")
            }

            pixelBufferPointer.dealloc(1)
        }
    }

    return appendSucceeded
}


func fillPixelBufferFromImage(image: UIImage, pixelBuffer: CVPixelBufferRef) {
    CVPixelBufferLockBaseAddress(pixelBuffer, 0)

    let pixelData = CVPixelBufferGetBaseAddress(pixelBuffer)
    let rgbColorSpace = CGColorSpaceCreateDeviceRGB()

    // Create CGBitmapContext
    let context = CGBitmapContextCreate(
        pixelData,
        Int(image.size.width),
        Int(image.size.height),
        8,
        CVPixelBufferGetBytesPerRow(pixelBuffer),
        rgbColorSpace,
        CGImageAlphaInfo.PremultipliedFirst.rawValue
    )

    // Draw image into context
    CGContextDrawImage(context, CGRectMake(0, 0, image.size.width, image.size.height), image.CGImage)

    CVPixelBufferUnlockBaseAddress(pixelBuffer, 0)
}


func saveVideoToLibrary(videoURL: NSURL) {
    PHPhotoLibrary.requestAuthorization { status in
        // Return if unauthorized
        guard status == .Authorized else {
            print("Error saving video: unauthorized access")
            return
        }

        // If here, save video to library
        PHPhotoLibrary.sharedPhotoLibrary().performChanges({
            PHAssetChangeRequest.creationRequestForAssetFromVideoAtFileURL(videoURL)
        }) { success, error in
            if !success {
                print("Error saving video: \(error)")
            }
        }
    }
}

回复于 2024-04-29T18:49:31+08:00

这是swift3版本如何将Images数组转换为Video

import Foundation
import AVFoundation
import UIKit

typealias CXEMovieMakerCompletion = (URL) -> Void
typealias CXEMovieMakerUIImageExtractor = (AnyObject) -> UIImage?


public class ImagesToVideoUtils: NSObject {

    static let paths = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)
    static let tempPath = paths[0] + "/exprotvideo.mp4"
    static let fileURL = URL(fileURLWithPath: tempPath)
//    static let tempPath = NSTemporaryDirectory() + "/exprotvideo.mp4"
//    static let fileURL = URL(fileURLWithPath: tempPath)


    var assetWriter:AVAssetWriter!
    var writeInput:AVAssetWriterInput!
    var bufferAdapter:AVAssetWriterInputPixelBufferAdaptor!
    var videoSettings:[String : Any]!
    var frameTime:CMTime!
    //var fileURL:URL!

    var completionBlock: CXEMovieMakerCompletion?
    var movieMakerUIImageExtractor:CXEMovieMakerUIImageExtractor?


    public class func videoSettings(codec:String, width:Int, height:Int) -> [String: Any]{
        if(Int(width) % 16 != 0){
            print("warning: video settings width must be divisible by 16")
        }

        let videoSettings:[String: Any] = [AVVideoCodecKey: AVVideoCodecJPEG, //AVVideoCodecH264,
                                           AVVideoWidthKey: width,
                                           AVVideoHeightKey: height]

        return videoSettings
    }

    public init(videoSettings: [String: Any]) {
        super.init()


        if(FileManager.default.fileExists(atPath: ImagesToVideoUtils.tempPath)){
            guard (try? FileManager.default.removeItem(atPath: ImagesToVideoUtils.tempPath)) != nil else {
                print("remove path failed")
                return
            }
        }


        self.assetWriter = try! AVAssetWriter(url: ImagesToVideoUtils.fileURL, fileType: AVFileTypeQuickTimeMovie)

        self.videoSettings = videoSettings
        self.writeInput = AVAssetWriterInput(mediaType: AVMediaTypeVideo, outputSettings: videoSettings)
        assert(self.assetWriter.canAdd(self.writeInput), "add failed")

        self.assetWriter.add(self.writeInput)
        let bufferAttributes:[String: Any] = [kCVPixelBufferPixelFormatTypeKey as String: Int(kCVPixelFormatType_32ARGB)]
        self.bufferAdapter = AVAssetWriterInputPixelBufferAdaptor(assetWriterInput: self.writeInput, sourcePixelBufferAttributes: bufferAttributes)
        self.frameTime = CMTimeMake(1, 5)
    }

    func createMovieFrom(urls: [URL], withCompletion: @escaping CXEMovieMakerCompletion){
        self.createMovieFromSource(images: urls as [AnyObject], extractor:{(inputObject:AnyObject) ->UIImage? in
            return UIImage(data: try! Data(contentsOf: inputObject as! URL))}, withCompletion: withCompletion)
    }

    func createMovieFrom(images: [UIImage], withCompletion: @escaping CXEMovieMakerCompletion){
        self.createMovieFromSource(images: images, extractor: {(inputObject:AnyObject) -> UIImage? in
            return inputObject as? UIImage}, withCompletion: withCompletion)
    }

    func createMovieFromSource(images: [AnyObject], extractor: @escaping CXEMovieMakerUIImageExtractor, withCompletion: @escaping CXEMovieMakerCompletion){
        self.completionBlock = withCompletion

        self.assetWriter.startWriting()
        self.assetWriter.startSession(atSourceTime: kCMTimeZero)

        let mediaInputQueue = DispatchQueue(label: "mediaInputQueue")
        var i = 0
        let frameNumber = images.count

        self.writeInput.requestMediaDataWhenReady(on: mediaInputQueue){
            while(true){
                if(i >= frameNumber){
                    break
                }

                if (self.writeInput.isReadyForMoreMediaData){
                    var sampleBuffer:CVPixelBuffer?
                    autoreleasepool{
                        let img = extractor(images[i])
                        if img == nil{
                            i += 1
                            print("Warning: counld not extract one of the frames")
                            //continue
                        }
                        sampleBuffer = self.newPixelBufferFrom(cgImage: img!.cgImage!)
                    }
                    if (sampleBuffer != nil){
                        if(i == 0){
                            self.bufferAdapter.append(sampleBuffer!, withPresentationTime: kCMTimeZero)
                        }else{
                            let value = i - 1
                            let lastTime = CMTimeMake(Int64(value), self.frameTime.timescale)
                            let presentTime = CMTimeAdd(lastTime, self.frameTime)
                            self.bufferAdapter.append(sampleBuffer!, withPresentationTime: presentTime)
                        }
                        i = i + 1
                    }
                }
            }
            self.writeInput.markAsFinished()
            self.assetWriter.finishWriting {
                DispatchQueue.main.sync {
                    self.completionBlock!(ImagesToVideoUtils.fileURL)
                }
            }
        }
    }

    func newPixelBufferFrom(cgImage:CGImage) -> CVPixelBuffer?{
        let options:[String: Any] = [kCVPixelBufferCGImageCompatibilityKey as String: true, kCVPixelBufferCGBitmapContextCompatibilityKey as String: true]
        var pxbuffer:CVPixelBuffer?
        let frameWidth = self.videoSettings[AVVideoWidthKey] as! Int
        let frameHeight = self.videoSettings[AVVideoHeightKey] as! Int

        let status = CVPixelBufferCreate(kCFAllocatorDefault, frameWidth, frameHeight, kCVPixelFormatType_32ARGB, options as CFDictionary?, &pxbuffer)
        assert(status == kCVReturnSuccess && pxbuffer != nil, "newPixelBuffer failed")

        CVPixelBufferLockBaseAddress(pxbuffer!, CVPixelBufferLockFlags(rawValue: 0))
        let pxdata = CVPixelBufferGetBaseAddress(pxbuffer!)
        let rgbColorSpace = CGColorSpaceCreateDeviceRGB()
        let context = CGContext(data: pxdata, width: frameWidth, height: frameHeight, bitsPerComponent: 8, bytesPerRow: CVPixelBufferGetBytesPerRow(pxbuffer!), space: rgbColorSpace, bitmapInfo: CGImageAlphaInfo.noneSkipFirst.rawValue)
        assert(context != nil, "context is nil")

        context!.concatenate(CGAffineTransform.identity)
        context!.draw(cgImage, in: CGRect(x: 0, y: 0, width: cgImage.width, height: cgImage.height))
        CVPixelBufferUnlockBaseAddress(pxbuffer!, CVPixelBufferLockFlags(rawValue: 0))
        return pxbuffer
    }
}

我将它与屏幕截图一起使用，基本上创建了一个屏幕截图视频，这里是the full story/complete example .

回复于 2024-04-29T18:49:31+08:00

-5

刚刚将@Scott Raposa的答案翻译成了swift3（有一些变化很小）：

import AVFoundation
import UIKit
import Photos

struct RenderSettings {

    var size : CGSize = .zero
    var fps: Int32 = 6   // frames per second
    var avCodecKey = AVVideoCodecH264
    var videoFilename = "render"
    var videoFilenameExt = "mp4"


    var outputURL: URL {
        // Use the CachesDirectory so the rendered video file sticks around as long as we need it to.
        // Using the CachesDirectory ensures the file won't be included in a backup of the app.
        let fileManager = FileManager.default
        if let tmpDirURL = try? fileManager.url(for: .cachesDirectory, in: .userDomainMask, appropriateFor: nil, create: true) {
            return tmpDirURL.appendingPathComponent(videoFilename).appendingPathExtension(videoFilenameExt)
        }
        fatalError("URLForDirectory() failed")
    }
}


class ImageAnimator {

    // Apple suggests a timescale of 600 because it's a multiple of standard video rates 24, 25, 30, 60 fps etc.
    static let kTimescale: Int32 = 600

    let settings: RenderSettings
    let videoWriter: VideoWriter
    var images: [UIImage]!

    var frameNum = 0

    class func saveToLibrary(videoURL: URL) {
        PHPhotoLibrary.requestAuthorization { status in
            guard status == .authorized else { return }

            PHPhotoLibrary.shared().performChanges({
                PHAssetChangeRequest.creationRequestForAssetFromVideo(atFileURL: videoURL)
            }) { success, error in
                if !success {
                    print("Could not save video to photo library:", error)
                }
            }
        }
    }

    class func removeFileAtURL(fileURL: URL) {
        do {
            try FileManager.default.removeItem(atPath: fileURL.path)
        }
        catch _ as NSError {
            // Assume file doesn't exist.
        }
    }

    init(renderSettings: RenderSettings) {
        settings = renderSettings
        videoWriter = VideoWriter(renderSettings: settings)
//        images = loadImages()
    }

    func render(completion: (()->Void)?) {

        // The VideoWriter will fail if a file exists at the URL, so clear it out first.
        ImageAnimator.removeFileAtURL(fileURL: settings.outputURL)

        videoWriter.start()
        videoWriter.render(appendPixelBuffers: appendPixelBuffers) {
            ImageAnimator.saveToLibrary(videoURL: self.settings.outputURL)
            completion?()
        }

    }

//    // Replace this logic with your own.
//    func loadImages() -> [UIImage] {
//        var images = [UIImage]()
//        for index in 1...10 {
//            let filename = "\(index).jpg"
//            images.append(UIImage(named: filename)!)
//        }
//        return images
//    }

    // This is the callback function for VideoWriter.render()
    func appendPixelBuffers(writer: VideoWriter) -> Bool {

        let frameDuration = CMTimeMake(Int64(ImageAnimator.kTimescale / settings.fps), ImageAnimator.kTimescale)

        while !images.isEmpty {

            if writer.isReadyForData == false {
                // Inform writer we have more buffers to write.
                return false
            }

            let image = images.removeFirst()
            let presentationTime = CMTimeMultiply(frameDuration, Int32(frameNum))
            let success = videoWriter.addImage(image: image, withPresentationTime: presentationTime)
            if success == false {
                fatalError("addImage() failed")
            }

            frameNum += 1
        }

        // Inform writer all buffers have been written.
        return true
    }

}


class VideoWriter {

    let renderSettings: RenderSettings

    var videoWriter: AVAssetWriter!
    var videoWriterInput: AVAssetWriterInput!
    var pixelBufferAdaptor: AVAssetWriterInputPixelBufferAdaptor!

    var isReadyForData: Bool {
        return videoWriterInput?.isReadyForMoreMediaData ?? false
    }

    class func pixelBufferFromImage(image: UIImage, pixelBufferPool: CVPixelBufferPool, size: CGSize) -> CVPixelBuffer {

        var pixelBufferOut: CVPixelBuffer?

        let status = CVPixelBufferPoolCreatePixelBuffer(kCFAllocatorDefault, pixelBufferPool, &pixelBufferOut)
        if status != kCVReturnSuccess {
            fatalError("CVPixelBufferPoolCreatePixelBuffer() failed")
        }

        let pixelBuffer = pixelBufferOut!

        CVPixelBufferLockBaseAddress(pixelBuffer, CVPixelBufferLockFlags(rawValue: 0))

        let data = CVPixelBufferGetBaseAddress(pixelBuffer)
        let rgbColorSpace = CGColorSpaceCreateDeviceRGB()
        let context = CGContext(data: data, width: Int(size.width), height: Int(size.height),
                                bitsPerComponent: 8, bytesPerRow: CVPixelBufferGetBytesPerRow(pixelBuffer), space: rgbColorSpace, bitmapInfo: CGImageAlphaInfo.premultipliedFirst.rawValue)

        context!.clear(CGRect(x:0,y: 0,width: size.width,height: size.height))

        let horizontalRatio = size.width / image.size.width
        let verticalRatio = size.height / image.size.height
        //aspectRatio = max(horizontalRatio, verticalRatio) // ScaleAspectFill
        let aspectRatio = min(horizontalRatio, verticalRatio) // ScaleAspectFit

        let newSize = CGSize(width: image.size.width * aspectRatio, height: image.size.height * aspectRatio)

        let x = newSize.width < size.width ? (size.width - newSize.width) / 2 : 0
        let y = newSize.height < size.height ? (size.height - newSize.height) / 2 : 0

        context?.draw(image.cgImage!, in: CGRect(x:x,y: y, width: newSize.width, height: newSize.height))
        CVPixelBufferUnlockBaseAddress(pixelBuffer, CVPixelBufferLockFlags(rawValue: 0))

        return pixelBuffer
    }

    init(renderSettings: RenderSettings) {
        self.renderSettings = renderSettings
    }

    func start() {

        let avOutputSettings: [String: Any] = [
            AVVideoCodecKey: renderSettings.avCodecKey,
            AVVideoWidthKey: NSNumber(value: Float(renderSettings.size.width)),
            AVVideoHeightKey: NSNumber(value: Float(renderSettings.size.height))
        ]

        func createPixelBufferAdaptor() {
            let sourcePixelBufferAttributesDictionary = [
                kCVPixelBufferPixelFormatTypeKey as String: NSNumber(value: kCVPixelFormatType_32ARGB),
                kCVPixelBufferWidthKey as String: NSNumber(value: Float(renderSettings.size.width)),
                kCVPixelBufferHeightKey as String: NSNumber(value: Float(renderSettings.size.height))
            ]
            pixelBufferAdaptor = AVAssetWriterInputPixelBufferAdaptor(assetWriterInput: videoWriterInput,
                                                                      sourcePixelBufferAttributes: sourcePixelBufferAttributesDictionary)
        }

        func createAssetWriter(outputURL: URL) -> AVAssetWriter {
            guard let assetWriter = try? AVAssetWriter(outputURL: outputURL, fileType: AVFileTypeMPEG4) else {
                fatalError("AVAssetWriter() failed")
            }

            guard assetWriter.canApply(outputSettings: avOutputSettings, forMediaType: AVMediaTypeVideo) else {
                fatalError("canApplyOutputSettings() failed")
            }

            return assetWriter
        }

        videoWriter = createAssetWriter(outputURL: renderSettings.outputURL)
        videoWriterInput = AVAssetWriterInput(mediaType: AVMediaTypeVideo, outputSettings: avOutputSettings)

        if videoWriter.canAdd(videoWriterInput) {
            videoWriter.add(videoWriterInput)
        }
        else {
            fatalError("canAddInput() returned false")
        }

        // The pixel buffer adaptor must be created before we start writing.
        createPixelBufferAdaptor()

        if videoWriter.startWriting() == false {
            fatalError("startWriting() failed")
        }

        videoWriter.startSession(atSourceTime: kCMTimeZero)

        precondition(pixelBufferAdaptor.pixelBufferPool != nil, "nil pixelBufferPool")
    }

    func render(appendPixelBuffers: ((VideoWriter)->Bool)?, completion: (()->Void)?) {

        precondition(videoWriter != nil, "Call start() to initialze the writer")

        let queue = DispatchQueue(label: "mediaInputQueue")
        videoWriterInput.requestMediaDataWhenReady(on: queue) {
            let isFinished = appendPixelBuffers?(self) ?? false
            if isFinished {
                self.videoWriterInput.markAsFinished()
                self.videoWriter.finishWriting() {
                    DispatchQueue.main.async {
                        completion?()
                    }
                }
            }
            else {
                // Fall through. The closure will be called again when the writer is ready.
            }
        }
    }

    func addImage(image: UIImage, withPresentationTime presentationTime: CMTime) -> Bool {

        precondition(pixelBufferAdaptor != nil, "Call start() to initialze the writer")

        let pixelBuffer = VideoWriter.pixelBufferFromImage(image: image, pixelBufferPool: pixelBufferAdaptor.pixelBufferPool!, size: renderSettings.size)
        return pixelBufferAdaptor.append(pixelBuffer, withPresentationTime: presentationTime)
    }

}

回复于 2024-04-29T18:49:31+08:00

7
好吧，这有点难以在纯Objective-C中实现....如果你正在为越狱设备开发，一个好主意是从你的应用程序内部使用命令行工具ffmpeg . 使用如下命令从图像创建电影非常容易：
```
ffmpeg -r 10 -b 1800 -i %03d.jpg test1800.mp4
```
请注意，图像必须按顺序命名，并且也可以放在同一目录中 . 有关更多信息，请查看：http://electron.mit.edu/~gsteele/ffmpeg/
回复于 2024-04-29T18:49:31+08:00
20

使用AVAssetWriter将图像写为电影 . 我已在这里回答： - https://stackoverflow.com/a/19166876/1582217

回复于 2024-04-29T18:49:31+08:00

如何将UIImage数组导出为电影？

9 回答

第1部分：进行设置

第2部分：ImageAnimator

第3部分：VideoWriter

第4部分：实现目标

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