視頻采集

AVFoundation 完成視頻采集,做個筆記吧.

初始化頁面布局

UILabel *titleLabel = [[UILabel alloc] init];
titleLabel.text = @"音視頻采集";
[self.view addSubview:titleLabel];
[titleLabel mas_makeConstraints:^(MASConstraintMaker *make) {
    make.top.equalTo(self.view).offset(30);
    make.centerX.equalTo(self.view);
}];

UIButton *beginInputVideo = [UIButton buttonWithType:UIButtonTypeCustom];
[beginInputVideo setTitle:@"開始視頻采集" forState:UIControlStateNormal];
[beginInputVideo setTitle:@"停止視頻采集" forState:UIControlStateSelected];
beginInputVideo.backgroundColor = [UIColor orangeColor];
[beginInputVideo addTarget:self action:@selector(beginInputVideoClcik:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:beginInputVideo];
[beginInputVideo mas_makeConstraints:^(MASConstraintMaker *make) {
    make.top.equalTo(titleLabel.mas_bottom).offset(20);
    make.centerX.equalTo(titleLabel);
    make.width.equalTo(@150);
}];

self.captureVideoPreviewView = [[UIView alloc] init];
self.captureVideoPreviewView.backgroundColor = [UIColor whiteColor];
[self.view addSubview:self.captureVideoPreviewView];
[self.captureVideoPreviewView mas_makeConstraints:^(MASConstraintMaker *make) {
    make.top.equalTo(beginInputVideo.mas_bottom).offset(20);
    make.left.right.bottom.equalTo(self.view);
}];

懶加載需要用的對象

/** 圖像sesson */ 
@property (nonatomic, strong) AVCaptureSession *captureSession;

/** 采集數(shù)據(jù)用的相機設(shè)備 */
@property (nonatomic, strong) AVCaptureDevice *inputCamera;

/** 輸入 */
@property (nonatomic, strong) AVCaptureDeviceInput *captureDeviceInput;

/** 輸出 */
@property (nonatomic, strong) AVCaptureVideoDataOutput *captureVideoDataOutput;

/** 相機采集頁面的layer */
@property (nonatomic, strong) AVCaptureVideoPreviewLayer *captureVideoPreviewLayer;

/** 相機采集頁面View */
@property (nonatomic, strong) UIView *captureVideoPreviewView;

下面是懶加載的代碼

- (AVCaptureSession *)captureSession {
    if (!_captureSession) {
        _captureSession = [[AVCaptureSession alloc] init];
        // 設(shè)置session顯示分辨率, 用于設(shè)置output輸出流的bitrate或者說畫面質(zhì)量
        [_captureSession setSessionPreset:AVCaptureSessionPresetHigh];
        /*
         AVCaptureSessionPresetHigh  質(zhì)量最高
         AVCaptureSessionPresetPhoto Photo模式不能輸出視頻
         AVCaptureSessionPresetMedium 中等質(zhì)量
         AVCaptureSessionPresetLow 最低質(zhì)量
         AVCaptureSessionPreset320x240 320x240大刑泶伞（不支持IPhone）
         AVCaptureSessionPreset352x288 （支持iPhone）
         AVCaptureSessionPreset640x480（支持iPhone）等等...
         */
        if ([_captureSession canAddInput:self.captureDeviceInput]) {
            [_captureSession addInput:self.captureDeviceInput];
        }
        if ([_captureSession canAddOutput:self.captureVideoDataOutput]) {
            [_captureSession addOutput:self.captureVideoDataOutput];
        }
    }
    return _captureSession;
}
- (AVCaptureDevice *)inputCamera {
    if (!_inputCamera) {
        NSArray *devices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
        for (AVCaptureDevice *device in devices) {
            if ([device position] == AVCaptureDevicePositionBack) {
                _inputCamera = device;
            }
        }
    }
    return _inputCamera;
}

- (AVCaptureDeviceInput *)captureDeviceInput {
    if (!_captureDeviceInput) {
        NSError *error;
        _captureDeviceInput = [[AVCaptureDeviceInput alloc] initWithDevice:self.inputCamera error:&error];
        NSLog(@"%@", error);
    }
    return _captureDeviceInput;
}

- (AVCaptureVideoDataOutput *)captureVideoDataOutput {
    if (!_captureVideoDataOutput) {
        _captureVideoDataOutput = [[AVCaptureVideoDataOutput alloc] init];
        _captureVideoDataOutput.alwaysDiscardsLateVideoFrames = YES;
        [_captureVideoDataOutput setAlwaysDiscardsLateVideoFrames:NO];
        [_captureVideoDataOutput setVideoSettings:[NSDictionary dictionaryWithObject:[NSNumber numberWithInt:kCVPixelFormatType_420YpCbCr8BiPlanarFullRange] forKey:(id)kCVPixelBufferPixelFormatTypeKey]];
        [_captureVideoDataOutput setSampleBufferDelegate:self queue:encodeQueue];
        AVCaptureConnection *captureConnection = [_captureVideoDataOutput connectionWithMediaType:AVMediaTypeVideo];
        [captureConnection setVideoOrientation:AVCaptureVideoOrientationPortrait | AVCaptureVideoOrientationLandscapeRight | AVCaptureVideoOrientationLandscapeLeft];
    }
    return _captureVideoDataOutput;
}

- (AVCaptureVideoPreviewLayer *)captureVideoPreviewLayer {
    if (!_captureVideoPreviewLayer) {
        _captureVideoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:self.captureSession];
        /*
         AVLayerVideoGravityResizeAspect        // 適合層范圍內(nèi)(完全顯示,可能有黑邊)
         AVLayerVideoGravityResizeAspectFill    // 填充層邊界(平鋪,不拉伸,但是會被裁剪,內(nèi)容可能顯示不全)
         AVLayerVideoGravityResize              // 拉伸填充層邊界(拉伸填充視圖)
         */
        [_captureVideoPreviewLayer setVideoGravity:AVLayerVideoGravityResizeAspect];
    }
    return _captureVideoPreviewLayer;
}

開始視頻采集

- (void)beginInputVideo {

    self.captureVideoPreviewLayer.frame = self.captureVideoPreviewView.bounds;
    
    self.captureVideoPreviewLayer.backgroundColor = [UIColor blackColor].CGColor;
    
    [self.captureVideoPreviewView.layer addSublayer:self.captureVideoPreviewLayer];
    
    [self.captureSession startRunning];
    
}

采集到視頻數(shù)據(jù)的回調(diào)

/**
 采集到數(shù)據(jù)的回調(diào)

 @param output outPut對象
 @param sampleBuffer 數(shù)據(jù)
 @param connection 鏈接
 */
- (void)captureOutput:(AVCaptureOutput *)output didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection {
    NSLog(@"%@", sampleBuffer);
}

注: 如發(fā)現(xiàn)問題,請留言.謝謝.