从CMSampleBuffer转换为UIImage对象

问题描述

| 我尝试了一个示例，该示例使用文档中提供的AV Foundation从摄像机捕获视频帧作为图像，即 http://developer.apple.com/library/ios/#qa/qa1702/_index.html 但是在从“ 0”中获取UIImage对象的委托方法中，给出的方法未构建。 意味着我也已经导入了AVFoundation框架，但是它给出了14个错误，如

_CVPixelBufferUnlockBaseAddress

，引用自：。 如果有人知道如何解决，请帮助我。 预先感谢。如果有人知道请告诉我。     

解决方法

这是捕获并从捕获的数据中获取图像的代码：

-(IBAction)startCapture
{
    //session object
    captureSession = [[AVCaptureSession alloc]init];
    captureSession.sessionPreset = AVCaptureSessionPresetMedium;

    AVCaptureVideoPreviewLayer *previewLayer = [AVCaptureVideoPreviewLayer layerWithSession:captureSession];
    previewLayer.frame = CGRectMake(0,10,320,200); ////self.view.frame; //
    [self.view.layer addSublayer:previewLayer];

    NSError *error = nil;
    AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];

    //input object
    AVCaptureDeviceInput *inputDevice = [[AVCaptureDeviceInput alloc]initWithDevice:device error:&error];
    [captureSession addInput:inputDevice];

    stillImageOutput = [[AVCaptureStillImageOutput alloc] init];
    NSDictionary *outputSettings = [[NSDictionary alloc] initWithObjectsAndKeys: AVVideoCodecJPEG,AVVideoCodecKey,nil];
    [stillImageOutput setOutputSettings:outputSettings];

    [captureSession addOutput:stillImageOutput];
    [captureSession startRunning];
}

-(IBAction) captureNow
{
    AVCaptureConnection *videoConnection = nil;
    for (AVCaptureConnection *connection in stillImageOutput.connections)
    {
        for (AVCaptureInputPort *port in [connection inputPorts])
        {
            if ([[port mediaType] isEqual:AVMediaTypeVideo] )
            {
                videoConnection = connection;
                break;
            }
        }
        if (videoConnection) { break; }
    }

    NSLog(@\"about to request a capture from: %@\",stillImageOutput);
    [stillImageOutput captureStillImageAsynchronouslyFromConnection:videoConnection completionHandler: ^(CMSampleBufferRef imageSampleBuffer,NSError *error)
     {
         CFDictionaryRef exifAttachments = CMGetAttachment( imageSampleBuffer,kCGImagePropertyExifDictionary,NULL);

         NSLog(@\"exif Attachments:%@\",exifAttachments);
         if (exifAttachments)
         {
             NSData *imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageSampleBuffer];

             UIImage *image = [[UIImage alloc] initWithData:imageData];
             self.vImage.image = image;
             // Do something with the attachments.

         }
         else
             NSLog(@\"no attachments\");   
     }];
}

    ,您的最终目标是什么-您是否打算将视频录制到视频文件中。还是仅捕获特定的帧？我有一个使用AVCaptureSession捕获带有音频的视频文件的可行示例，如果可以帮助我发布一些代码片段-但由于涉及到一些细节，我想特别了解您要执行的操作。 干杯， 麦可     ,当assetWriter完成录制影片/捕获图像后将其保存到库中。 将其放在实现文件的上方*这是保存视频文件的示例，但是您可以更改它以保存图像：

ALAssetsLibraryWriteVideoCompletionBlock _videoCompblock = ^(NSURL *assetURL,NSError *error){
if(assetURL){
    NSLog(@\"Saved to camera roll with Video AssetUrl : %@\",[assetURL absoluteString]);
    NSError *error;

    NSFileManager *fileManager = [NSFileManager defaultManager];
    NSDictionary *attributes = [fileManager attributesOfItemAtPath:[assetURL absoluteString] error:&error];

    if (attributes){
        long fileSize = [[attributes objectForKey:NSFileSize] longValue];// unsigned long long
        NSLog(@\"%d\",fileSize);
    }

}else if(error){
    NSLog(@\"The Error occured : %@\",[error localizedDescription]);
}

}; 然后，您需要一个使用上述代码块的函数-因此，当您捕获会话完成记录时，请执行以下操作：

-(void) stopRecording{
writing = NO;
isRecording = NO;
[audioInput markAsFinished];//if you have an audio writer stop it too
[videoInput markAsFinished];
[assetWriter endSessionAtSourceTime:[frTimer currentTimeStamp]];
[assetWriter finishWriting];

finished = YES;

[videoUtilities saveToCamera:[assetWriter outputURL]];
NSLog(@\"%@\",[[assetWriter outputURL] absoluteString]);

} 这会触发“保存到相机”功能，看起来像这样：

+(void) saveToCamera:(NSURL *)urlPath{

ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];

AVAsset *movFile = [AVURLAsset URLAssetWithURL:urlPath options:nil];
NSLog(@\"Movie File %@\",movFile);

BOOL isSupported = [library videoAtPathIsCompatibleWithSavedPhotosAlbum:urlPath];

if(isSupported){
    NSLog(@\"IS SUPPORTED - SAVING TO CAMERA ROLL\");
    [library writeVideoAtPathToSavedPhotosAlbum:urlPath completionBlock:_videoCompblock];

}

} 如果要在拍摄时实时显示保存的图像-拍摄照片时需要将UIImageData复制到UIImage对象-并将其分配为UIImageView的图像。或者，您可以枚举assetLibrary并将其从那里拉出来。 希望这可以帮助， 干杯， 麦可     ,您必须导入CoreMedia.framework和CoreVideo.framework