相关疑难解决方法(0)

我一直在试图让我的头发试图让AVFoundation相机以正确的方向(即设备方向)拍摄图片,但我无法让它工作.

我看过教程,我看过WWDC演示文稿,我已经下载了WWDC示例程序,但即便如此也没有.

我的应用程序的代码是......

AVCaptureConnection *videoConnection = [CameraVC connectionWithMediaType:AVMediaTypeVideo fromConnections:[imageCaptureOutput connections]];
if ([videoConnection isVideoOrientationSupported])
{
    [videoConnection setVideoOrientation:[UIApplication sharedApplication].statusBarOrientation];
}

[imageCaptureOutput captureStillImageAsynchronouslyFromConnection:videoConnection
                                                completionHandler:^(CMSampleBufferRef imageDataSampleBuffer, NSError *error)
{
    if (imageDataSampleBuffer != NULL)
    {
        //NSLog(@"%d", screenOrientation);

        //CMSetAttachment(imageDataSampleBuffer, kCGImagePropertyOrientation, [NSString stringWithFormat:@"%d", screenOrientation], 0);

        NSData *imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageDataSampleBuffer];
        UIImage *image = [[UIImage alloc] initWithData:imageData];

        [self processImage:image];
    }
}];

(processImage使用与WWDC代码相同的writeImage ...方法)

并且WWDC应用程序的代码是......

AVCaptureConnection *videoConnection = [AVCamDemoCaptureManager connectionWithMediaType:AVMediaTypeVideo fromConnections:[[self stillImageOutput] connections]];
        if ([videoConnection isVideoOrientationSupported]) {
            [videoConnection setVideoOrientation:AVCaptureVideoOrientationPortrait];
        }

[[self stillImageOutput] captureStillImageAsynchronouslyFromConnection:videoConnection
                                                             completionHandler:^(CMSampleBufferRef imageDataSampleBuffer, NSError *error) {
                                                                 if …

我试图在mac os x上镜像从网络摄像头收到的视频.我希望在收到视频缓冲区后避免进行手动翻转/转换.所以,我想设置AVCaptureSession这样的captureOutput方法接收的视频缓冲区AVCaptureVideoDataOutputSampleBufferDelegate由AVFoundation本身镜像.我不想使用预览图层.

在iMac(10.8.5)上,镜像视频,AVCaptureConnection isVideoMirroringSupported在设置videoMirrored属性之前已成功通过测试.但代理中收到的视频缓冲区captureOutput未镜像.

注意:当我按照这个 SO答案时,iOS上的视频镜像是成功的.但它对mac os x没有帮助.

使用的代码如下.此帖子遗漏了错误检查.

    //create session
    _session = [[AVCaptureSession alloc] init];

    //get capture device
    _device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];

    //create sesion input
    NSError * error;
    _sessionInput = [AVCaptureDeviceInput deviceInputWithDevice:_device error:&error];

    //create session output
    _sessionOutput = [[AVCaptureVideoDataOutput alloc] init];
    [_sessionOutput setAlwaysDiscardsLateVideoFrames:YES];
    [[_sessionOutput connectionWithMediaType:AVMediaTypeVideo] setEnabled:YES];
    NSDictionary *videoSettings = [NSDictionary dictionaryWithObject: [NSNumber numberWithUnsignedInt:kCVPixelFormatType_32BGRA] forKey:(id)kCVPixelBufferPixelFormatTypeKey];
    [_sessionOutput setVideoSettings:videoSettings];

    //serial queue to process video frames
    dispatch_queue_t …

我正在使用AVAssetReader和AVAssetWriter将视频从一个文件转码到另一个文件.AVAssetReaderTrackOutput已添加到AVAssetReader.遗憾的是,单曲目的preferredTransform属性未从输入复制到输出,因此以纵向方向录制的视频以横向方式播放.

如何在输出文件中设置preferredTransform属性？