如何将UIImage数组导出为电影？ [英] How do I export UIImage array as a movie?

问题描述

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

我希望有人可以帮助我，或者给我一个像我想要的代码片段。

编辑：以供将来参考 - 应用解决方案后，如果视频看起来扭曲，请确保要捕获的图像/区域的宽度为在这里经过许多小时的努力后发现：

为什么我的电影从UIImages被扭曲？

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

解决方案

看看 AV AssetWriter 以及其他 AVFoundation框架。作者的输入类型为 AVAssetWriterInput ，而AVAssetWriterInput又有一种方法叫做 appendSampleBuffer：，可让您将单独的帧添加到视频流中。基本上你必须：

1）连线作者：

  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];如果ARC 
 
 NSParameterAssert（writerInput）; //保留应该被删除
 NSParameterAssert（[videoWriter canAddInput：writerInput]）; 
 [videoWriter addInput：writerInput]; 
  

2）开始会话

  [videoWriter startWriting]; 
 [videoWriter startSessionAtSourceTime ... ...] //如果不确定，使用kCMTimeZero 
  

3）写一些样本：

  //或者你可以使用AVAssetWriterInputPixelBufferAdaptor。 
 //这可以让您从CVPixelBuffer 
 //提供写入程序输入数据，这很容易从CGImage创建。 
 [writerInput appendSampleBuffer：sampleBuffer]; 
  

4）完成会话：

  [writerInput markAsFinished]; 
 [videoWriter endSessionAtSourceTime ... ...]; //可选可以调用finishWriting而不指定endTime 
 [videoWriter finishWriting]; //在ios6中弃用
 / * 
 [videoWriter finishWritingWithCompletionHandler：...]; // ios 6.0+ 
 * / 
  

您仍然必须填写很多空白，但我认为唯一真正困难的部分是从 CGImage 获取像素缓冲区：

   - （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（上下文，CGRectMake（0，0，CGImageGetWidth（image），
 CGImageGetHeight（image）），image）; 
 CGColorSpaceRelease（rgbColorSpace）; 
 CGContextRelease（context）; 
 
 CVPixelBufferUnlockBaseAddress（pxbuffer，0）; 
 
返回pxbuffer; 
} 
  

frameSize 是一个 CGSize 描述您的目标框架大小和 frameTransform 是一个 CGAffineTransform 当您将图像绘制到框架中时，您可以将图像转换为图像。

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

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

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?

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

解决方案

Take a look at AVAssetWriter and 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:

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+
*/

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:

- (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 is a CGSize describing your target frame size and frameTransform is a CGAffineTransform that lets you transform the images when you draw them into frames.

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