ios 如何将 UIImage 数组导出为电影?

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时间:2020-08-30 17:45:07  来源:igfitidea点击:

How do I export UIImage array as a movie?

iosiphoneuiimageexportavfoundation

提问by Nuker

I have a serious problem: I have an NSArraywith several UIImageobjects. What I now want to do, is create movie from those UIImages. But I don't have any idea how to do so.

我有一个严重的问题:我有NSArray几个UIImage对象。我现在想做的是从这些文件中制作电影UIImages。但我不知道该怎么做。

I hope someone can help me or send me a code snippet which does something like I want.

我希望有人可以帮助我或向我发送一个代码片段,它可以做我想要的事情。

Edit:For future reference - After applying the solution, if the video looks distorted, make sure the width of the images/area you are capturing is a multiple of 16. Found after many hours of struggle here:
Why does my movie from UIImages gets distorted?

编辑: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。经过数小时的努力在这里找到:
为什么我的电影来自 UIImages扭曲?

Here is the complete solution (just ensure width is multiple of 16)
http://codethink.no-ip.org/wordpress/archives/673

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

回答by zoul

Take a look at AVAssetWriterand the rest of the AVFoundation framework. The writer has an input of type AVAssetWriterInput, which in turn has a method called appendSampleBuffer:that lets you add individual frames to a video stream. Essentially you'll have to:

看看AVAssetWriterAVFoundation 框架的其余部分。编写器有一个AVAssetWriterInput类型的输入,而该输入又具有一个名为appendSampleBuffer:的方法,可让您将单个帧添加到视频流中。基本上你必须:

1) Wire the writer:

1) 连线写入器:

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:

2)启动一个会话:

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

3) Write some samples:

3)写一些样本:

// 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:

4) 结束会话:

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

You'll still have to fill-in a lot of blanks, but I think that the only really hard remaining part is getting a pixel buffer from a CGImage:

您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以下位置获取像素缓冲区CGImage

- (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;
}

frameSizeis a CGSizedescribing your target frame size and frameTransformis a CGAffineTransformthat lets you transform the images when you draw them into frames.

frameSizeCGSize描述你的目标帧尺寸,并frameTransform是一个CGAffineTransform让当你画他们到帧你变换图像。

回答by Praxiteles

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

这是 iOS8 上最新的 Objective-C 工作代码。

We had to make a variety of tweaks to @Zoul's answer above to get it to work on the latest version of Xcode and iOS8. Here is our complete working code that takes an array of UIImages, makes them into a .mov file, saves it to a temp directory, then moves it to the camera roll. We assembled code from multiple different posts to get this working. We have highlighted the traps we had to solve to get the code working in our comments.

我们必须对上面@Zoul 的回答进行各种调整,才能使其在最新版本的 Xcode 和 iOS8 上运行。这是我们完整的工作代码,它采用 UIImages 数组,将它们制作成 .mov 文件,将其保存到临时目录,然后将其移动到相机胶卷。我们从多个不同的帖子中组装了代码以使其正常工作。我们强调,我们必须解决让代码工作在我们的意见的陷阱。

(1) Create a collection of UIImages

(1)创建一个UIImages集合

[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)];
}

This is the main method that creates your AssetWriter and adds images to it for writing.

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

(2) 连接一个 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(NOTE: the method is continuing from above)

(3) 开始一个写Session(注意:方法是从上面继续的)

    //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(Note: Method continues from above)

(4) 结束会话(注:方法接上)

                //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
This method will give you a CV pixel buffer reference which is needed by the AssetWriter. This is obtained from a CGImageRef which you get from your UIImage (above).

(5) 将您的 UIImages 转换为 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 获得的 CGImageRef 获得的(上图)。

- (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 RollBecause AVAssetWriter cannot write directly to the camera roll, this moves the video from "tmp/temp.mov" (or whatever filename you named it above) to the camera roll.

(6) 将您的视频移动到相机胶卷因为 AVAssetWriter 不能直接写入相机胶卷,这会将视频从“tmp/temp.mov”(或您在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's answer above gives a nice outline of what you will be doing. We extensively commented this code so you can then see how it was done using working code.

上面 Zoul 的回答很好地概述了您将要做什么。我们对这段代码进行了广泛的评论,以便您可以看到它是如何使用工作代码完成的。

回答by scootermg

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

注意:这是一个 Swift 2.1 解决方案(iOS8+,XCode 7.2)

Last week I set out to write the iOS code to generate a video from images. I had a little bit of AVFoundation experience, but had never even heard of a CVPixelBuffer. I came across the answers on this page and also here. It took several days to dissect everything and put it all back together in Swift in a way that made sense to my brain. Below is what I came up with.

上周我开始编写 iOS 代码来从图像生成视频。我有一点 AVFoundation 的经验,但从未听说过 CVPixelBuffer。我在此页面和此处都找到了答案。我花了好几天时间来剖析所有内容,并以一种对我的大脑有意义的方式将它们重新组合到 Swift 中。下面是我想出来的。

NOTE: If you copy/paste all the code below into a single Swift file, it should compile. You'll just need to tweak loadImages()and the RenderSettingsvalues.

注意:如果您将下面的所有代码复制/粘贴到一个 Swift 文件中,它应该可以编译。你只需要调整loadImages()RenderSettings值。

Part 1: Setting things up

第 1 部分:设置

Here I group all the export-related settings into a single RenderSettingsstruct.

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")
    }
}

Part 2: The ImageAnimator

第 2 部分:ImageAnimator

The ImageAnimatorclass knows about your images and uses the VideoWriterclass to perform the rendering. The idea is to keep the video content code separate from the low-level AVFoundation code. I also added saveToLibrary()here as a class function which gets called at the end of the chain to save the video to the Photo Library.

ImageAnimator班知道你的图像,并使用VideoWriter类来进行渲染。这个想法是将视频内容代码与低级 AVFoundation 代码分开。我还在saveToLibrary()此处添加了一个类函数,该函数在链的末尾被调用以将视频保存到照片库中。

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
    }

}

Part 3: The VideoWriter

第 3 部分:VideoWriter

The VideoWriterclass does all AVFoundation heavy lifting. It's mostly a wrapper around AVAssetWriterand AVAssetWriterInput. It also contains fancy code written by not me that knows how to translate an image into a CVPixelBuffer.

VideoWriter级完成所有AVFoundation繁重。它主要是围绕AVAssetWriter和的包装AVAssetWriterInput。它还包含不是我写的花哨的代码,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)
    }

}

Part 4: Make it happen

第 4 部分:让它发生

Once everything is in place, these are your 3 magic lines:

一切就绪后,这些是您的 3 条魔线:

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

回答by Cameron E

I took Zoul's main ideas and incorporated the AVAssetWriterInputPixelBufferAdaptor method and made the beginnings of a little frameworks out of it.

我采纳了 Zoul 的主要思想,并结合了 AVAssetWriterInputPixelBufferAdaptor 方法,并从中创建了一些小框架。

Feel free to check it out and improve upon it! CEMovieMaker

请随时检查并改进它!CEMovieMaker

回答by Crashalot

Here's a Swift 2.x version tested on iOS 8. It combines answers from @Scott Raposa and @Praxiteles along with code from @acj contributed for another question. The code from @acj is here: https://gist.github.com/acj/6ae90aa1ebb8cad6b47b. @TimBull also provided code as well.

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

Like @Scott Raposa, I had never even heard of CVPixelBufferPoolCreatePixelBufferand several other functions, let alone understood how to use them.

像@Scott Raposa 一样,我什CVPixelBufferPoolCreatePixelBuffer至从未听说过和其他几个功能,更不用说了解如何使用它们了。

What you see below was cobbled together mostly by trial and error and from reading Apple docs. Please use with caution, and provide suggestions if there are mistakes.

您在下面看到的内容主要是通过反复试验和阅读 Apple 文档拼凑而成的。请谨慎使用,如有错误请提出建议。

Usage:

用法:

import UIKit
import AVFoundation
import Photos

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

Code:

代码:

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{ 
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
    }
}
.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)") } } } }

回答by Mikita Manko

Here's the swift3 version how to convert Images array to the Video

这是 swift3 版本如何将图像数组转换为视频

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)
    }

}

I use it together with screen capturing, to basically create a video of screen capturing, here's the full story/complete example.

我将它与屏幕捕获一起使用,基本上创建一个屏幕捕获视频,这里是完整的故事/完整示例

回答by Yedidya Reiss

Just translated @Scott Raposa answer to swift3 (with some very little changes):

刚刚翻译了@Scott Raposa 对 swift3 的回答(有一些很小的变化):

ffmpeg -r 10 -b 1800 -i %03d.jpg test1800.mp4

回答by Kostas.N

Well this is a bit hard to be implemented in pure Objective-C....If you are developing for jailbroken devices , a good idea is to use the command-line tool ffmpeg from inside your app. it's quite easy to create a movie from images with a command like:

嗯,这在纯 Objective-C 中实现起来有点困难......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。使用以下命令从图像创建电影非常容易:

##代码##

Note that the images have to be named sequentially , and also be placed in the same directory. For more information take a look at: http://electron.mit.edu/~gsteele/ffmpeg/

请注意,图像必须按顺序命名,并且也必须放在同一目录中。有关更多信息,请查看:http: //electron.mit.edu/~gsteele/ffmpeg/

回答by Mohd Iftekhar Qurashi

Use AVAssetWriter to write images as movie. I already have answered here:- https://stackoverflow.com/a/19166876/1582217

使用 AVAssetWriter 将图像写入电影。我已经在这里回答了:- https://stackoverflow.com/a/19166876/1582217