iPhone:AVCaptureSession 捕获输出崩溃 (AVCaptureVideoDataOutput) [英] iPhone: AVCaptureSession capture output crashing (AVCaptureVideoDataOutput)

问题描述

我正在捕获视频并将其转换为 CGImage 以对其进行处理.它将工作约 10 秒，获得内存警告然后崩溃(通常它表示数据格式化程序暂时不可用).有人可以帮我解决问题吗?

I'm capturing video and converting it to a CGImage to do processing on it. It will work for a ~10 seconds, get memory warning and then crash (usually it says data formatters were temporarily unavailable). Can someone help me solve the problem?

- (void) captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection {

// CONVERT CMSAMPLEBUFFER INTO A CGIMAGE
CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);

CVPixelBufferLockBaseAddress(imageBuffer,0);


uint8_t *baseAddress = (uint8_t *)CVPixelBufferGetBaseAddress(imageBuffer);
size_t bytesPerRow = CVPixelBufferGetBytesPerRow(imageBuffer);
size_t width = CVPixelBufferGetWidth(imageBuffer);
size_t height = CVPixelBufferGetHeight(imageBuffer);


CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
CGContextRef newContext = CGBitmapContextCreate(baseAddress, width, height, 8, bytesPerRow, colorSpace, kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedFirst);
CGImageRef cgimage = CGBitmapContextCreateImage(newContext);
UIImage *sourceImage= [UIImage imageWithCGImage:cgimage scale:1.0f orientation:UIImageOrientationLeftMirrored];
CGImageRelease(cgimage);
CGContextRelease(newContext);
CGColorSpaceRelease(colorSpace);

CVPixelBufferUnlockBaseAddress(imageBuffer,0);


// ***
// Adding code after this point to do image transformation usually causes it to crash
UIImage *rot = [self scaleAndRotateImage:sourceImage];
self.detectImage = rot;



}

转换图像的代码......

Code to transform the image....

- (UIImage*)scaleAndRotateImage:(UIImage *)image{
    int kMaxResolution = 320; // Or whatever

    CGImageRef imgRef = image.CGImage;

    CGFloat width = CGImageGetWidth(imgRef);
    CGFloat height = CGImageGetHeight(imgRef);

    CGAffineTransform transform = CGAffineTransformIdentity;
    CGRect bounds = CGRectMake(0, 0, width, height);
    if (width > kMaxResolution || height > kMaxResolution) {
        CGFloat ratio = width/height;
        if (ratio > 1) {
            bounds.size.width = kMaxResolution;
            bounds.size.height = bounds.size.width / ratio;
        }
        else {
            bounds.size.height = kMaxResolution;
            bounds.size.width = bounds.size.height * ratio;
        }
    }

    CGFloat scaleRatio = bounds.size.width / width;
    CGSize imageSize = CGSizeMake(CGImageGetWidth(imgRef), CGImageGetHeight(imgRef));
    CGFloat boundHeight;
    UIImageOrientation orient = image.imageOrientation;
    switch(orient) {

        case UIImageOrientationUp: //EXIF = 1
            transform = CGAffineTransformIdentity;
            break;

        case UIImageOrientationUpMirrored: //EXIF = 2
            transform = CGAffineTransformMakeTranslation(imageSize.width, 0.0);
            transform = CGAffineTransformScale(transform, -1.0, 1.0);
            break;

        case UIImageOrientationDown: //EXIF = 3
            transform = CGAffineTransformMakeTranslation(imageSize.width, imageSize.height);
            transform = CGAffineTransformRotate(transform, M_PI);
            break;

        case UIImageOrientationDownMirrored: //EXIF = 4
            transform = CGAffineTransformMakeTranslation(0.0, imageSize.height);
            transform = CGAffineTransformScale(transform, 1.0, -1.0);
            break;

        case UIImageOrientationLeftMirrored: //EXIF = 5
            boundHeight = bounds.size.height;
            bounds.size.height = bounds.size.width;
            bounds.size.width = boundHeight;
            transform = CGAffineTransformMakeTranslation(imageSize.height, imageSize.height);
            transform = CGAffineTransformScale(transform, -1.0, 1.0);
            transform = CGAffineTransformRotate(transform, 3.0 * M_PI / 2.0);
            break;

        case UIImageOrientationLeft: //EXIF = 6
            boundHeight = bounds.size.height;
            bounds.size.height = bounds.size.width;
            bounds.size.width = boundHeight;
            transform = CGAffineTransformMakeTranslation(0.0, imageSize.width);
            transform = CGAffineTransformRotate(transform, 3.0 * M_PI / 2.0);
            break;

        case UIImageOrientationRightMirrored: //EXIF = 7
            boundHeight = bounds.size.height;
            bounds.size.height = bounds.size.width;
            bounds.size.width = boundHeight;
            transform = CGAffineTransformMakeScale(-1.0, 1.0);
            transform = CGAffineTransformRotate(transform, M_PI / 2.0);
            break;

        case UIImageOrientationRight: //EXIF = 8
            boundHeight = bounds.size.height;
            bounds.size.height = bounds.size.width;
            bounds.size.width = boundHeight;
            transform = CGAffineTransformMakeTranslation(imageSize.height, 0.0);
            transform = CGAffineTransformRotate(transform, M_PI / 2.0);
            break;

        default:
            [NSException raise:NSInternalInconsistencyException format:@"Invalid image orientation"];

    }

    UIGraphicsBeginImageContext(bounds.size);

    CGContextRef context = UIGraphicsGetCurrentContext();

    if (orient == UIImageOrientationRight || orient == UIImageOrientationLeft) {
        CGContextScaleCTM(context, -scaleRatio, scaleRatio);
        CGContextTranslateCTM(context, -height, 0);
    }
    else {
        CGContextScaleCTM(context, scaleRatio, -scaleRatio);
        CGContextTranslateCTM(context, 0, -height);
    }

    CGContextConcatCTM(context, transform);

    CGContextDrawImage(UIGraphicsGetCurrentContext(), CGRectMake(0, 0, width, height), imgRef);
    UIImage *imageCopy = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    //[self setRotatedImage:imageCopy];
    return imageCopy;
}

这个功能只是背景，看看我是如何设置视频输出的...

This function is just background to see how I setup the video output...

AVCaptureVideoDataOutput *videoOut = [[AVCaptureVideoDataOutput alloc] init];
[videoOut setAlwaysDiscardsLateVideoFrames:YES];
[videoOut setVideoSettings:[NSDictionary dictionaryWithObject:[NSNumber numberWithInt:kCVPixelFormatType_32BGRA] forKey:(id)kCVPixelBufferPixelFormatTypeKey]]; // BGRA is necessary for manual preview
dispatch_queue_t my_queue = dispatch_queue_create("com.example.subsystem.taskXYZ", NULL);
[videoOut setSampleBufferDelegate:self queue:my_queue];
if ([self.captureSession canAddOutput:videoOut]) [self.captureSession addOutput:videoOut];
else NSLog(@"Couldn't add video output");
[videoOut release];

推荐答案

在设置视频输出时，新创建的dispatch queue没有释放.您可以使用

In setting up the video output, the newly created dispatch queue is not released. You can release it with

dispatch_release(queue);

但我不相信这个函数被频繁调用，所以泄漏可能来自其他地方.浏览了您的代码几次，找不到任何其他罪魁祸首...

But I don't believe this function gets called too often, so the leak probably originates elsewhere. Browsed your code several times, couldn't find any other culprits...

您是否尝试过使用泄漏仪器工具搜索泄漏?

Have you tried searching the leak with the Leaks instrument tool?

这篇关于iPhone:AVCaptureSession 捕获输出崩溃 (AVCaptureVideoDataOutput)的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！