問題

領(lǐng)導(dǎo)看了前面做的拍照，問了句"哪來的聲音",

"系統(tǒng)的，自帶的扎狱，你看系統(tǒng)的拍照也有聲音"

"有辦法能去掉嗎琳猫？挺糟心的"

"我試試"

思路

路漫漫其修遠(yuǎn)兮伟叛，吾在度娘+SDK中求索

拍磚AVCaptureVideoDataOutput, 代理方法中將CMSampleBufferRef轉(zhuǎn)成UIImage

上碼

• session設(shè)置不提

• layer設(shè)置可參考上篇 [iOS拍照定制之AVCapturePhotoOutput] 以及 上上篇[iOS寫在定制相機(jī)之前]

• 獲取攝像頭、取到設(shè)備輸入添加到session脐嫂、初始化videoOutput添加入session

AVCaptureDevice *device = [self cameraDevice];
if (!device) {
    NSLog(@"取得后置攝像頭出問題");
    return;;
}

NSError *error = nil;
self.videoInput = [[AVCaptureDeviceInput alloc] initWithDevice:device error:nil];

// 設(shè)備添加到會(huì)話中
if ([self.captureSession canAddInput:self.videoInput]) {
    [self.captureSession addInput:self.videoInput];
}

[self.videoOutput setSampleBufferDelegate:self queue:self.videoQueue];
if ([self.captureSession canAddOutput:self.videoOutput]) {
    [self.captureSession addOutput:self.videoOutput];
}

// 懶加載
- (AVCaptureVideoDataOutput *)videoOutput {
    if (!_videoOutput) {
        _videoOutput = [[AVCaptureVideoDataOutput alloc] init];
        _videoOutput.alwaysDiscardsLateVideoFrames = YES;
        _videoOutput.videoSettings = [NSDictionary dictionaryWithObject:[NSNumber numberWithInt:kCVPixelFormatType_32BGRA]
                                                                 forKey:(id)kCVPixelBufferPixelFormatTypeKey];
    }
    return _videoOutput;
}

- (dispatch_queue_t)videoQueue {
    if (!_videoQueue) {
        _videoQueue = dispatch_queue_create("queue", DISPATCH_QUEUE_SERIAL);
    }
    return _videoQueue;
}

• 代理AVCaptureVideoDataOutputSampleBufferDelegate

- (void)captureOutput:(AVCaptureOutput *)output didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection {
    @autoreleasepool {
        if (connection == [self.videoOutput connectionWithMediaType:AVMediaTypeVideo]) { // 視頻
            @synchronized (self) {
                UIImage *image = [self bufferToImage:sampleBuffer rect:self.scanView.scanRect];
                self.uploadImg = image;
            }
        }
    }
}

• CMSampleBufferRef轉(zhuǎn)成UIImage, 該方法有所調(diào)整统刮，截圖整張圖中的某一部分，按需設(shè)置账千。具體獲取指定區(qū)域圖片需自己調(diào)整

- (UIImage *)bufferToImage:(CMSampleBufferRef)sampleBuffer rect:(CGRect)rect {
    // Get a CMSampleBuffer's Core Video image buffer for the media data
    CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
    // Lock the base address of the pixel buffer
    CVPixelBufferLockBaseAddress(imageBuffer, 0);

    // Get the number of bytes per row for the pixel buffer
    void *baseAddress = CVPixelBufferGetBaseAddress(imageBuffer);

    // Get the number of bytes per row for the pixel buffer
    size_t bytesPerRow = CVPixelBufferGetBytesPerRow(imageBuffer);
    // Get the pixel buffer width and height
    size_t width = CVPixelBufferGetWidth(imageBuffer);
    size_t height = CVPixelBufferGetHeight(imageBuffer);

    // Create a device-dependent RGB color space
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();

    // Create a bitmap graphics context with the sample buffer data
    CGContextRef context = CGBitmapContextCreate(baseAddress, width, height, 8,
                                                 bytesPerRow, colorSpace, kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedFirst);
    // Create a Quartz image from the pixel data in the bitmap graphics context
    CGImageRef quartzImage = CGBitmapContextCreateImage(context);
    // Unlock the pixel buffer
    CVPixelBufferUnlockBaseAddress(imageBuffer,0);


    // Free up the context and color space
    CGContextRelease(context);
    CGColorSpaceRelease(colorSpace);
    
    // 獲取指定區(qū)域圖片
    CGRect dRect;
    CGSize msize = UIScreen.mainScreen.bounds.size;
    msize.height = msize.height - 150;
    CGFloat x = width * rect.origin.x / msize.width;
    CGFloat y = height * rect.origin.y / msize.height;
    CGFloat w = width * rect.size.width / msize.width;
    CGFloat h = height * rect.size.height / msize.height;
    dRect = CGRectMake(x, y, w, h);
    
    CGImageRef partRef = CGImageCreateWithImageInRect(quartzImage, dRect);
    
    // Create an image object from the Quartz image
    UIImage *image = [UIImage imageWithCGImage:partRef];

    // Release the Quartz image
    CGImageRelease(partRef);
    CGImageRelease(quartzImage);
    
    return image;
}

圖有了侥蒙，收工。怎么用圖匀奏，業(yè)務(wù)該干活了