iOS进阶之音视频采集和摄像头切换 聚焦功能

1.swift 3.0系统原生的数据采集

import UIKit
import AVFoundation

class InformationAcquisitionViewController: UIViewController {

    lazy var captureSession: AVCaptureSession = {
        // 创建捕捉会话
        let captureSession = AVCaptureSession()
        return captureSession
    }()
    
    // 视频输入
    var videoDeviceInput: AVCaptureDeviceInput?
    
    /// 视频连接
    var videoConnection : AVCaptureConnection?
    
    /// 视频预览图层
    lazy var previedLayer: AVCaptureVideoPreviewLayer = {
        let previedLayer = AVCaptureVideoPreviewLayer(session: self.captureSession)!
        previedLayer.frame = UIScreen.main.bounds
        return previedLayer
    }()
    // 聚焦图片
    lazy var focusImageView: UIImageView = {
        let foucusImageView = UIImageView(image: UIImage(named: "focus"))
        foucusImageView.frame = CGRect(x: 0, y: 0, width: 80, height: 61)
        self.view.addSubview(foucusImageView)
        return foucusImageView
    }()
    
    override func viewDidLoad() {
        super.viewDidLoad()

       setupCaputureVideo()
    }
}

// MARK:- 界面设置

extension InformationAcquisitionViewController {

    /// 音视频捕捉
    func setupCaputureVideo() {
        // 获取摄像头设备，默认后摄像头
        var videoDevice = getVideoDevice(.back)
        
        if videoDevice == nil {
            videoDevice = getVideoDevice(.front)
        }
        
        guard let video = videoDevice else {
            return
        }

        // 创建视频输入对象
        guard let videoDeviceInput = try? AVCaptureDeviceInput(device: video) else {
            return
        }
        self.videoDeviceInput = videoDeviceInput
        
        // 获取声音设备
        let audioDevice = AVCaptureDevice.defaultDevice(withMediaType: AVMediaTypeAudio)
        // 创建音频输入对象
        guard let audioDeviceInput = try? AVCaptureDeviceInput(device: audioDevice) else {
            return
        }
        
        // 添加至会话中，不能添加空
        if captureSession.canAddInput(videoDeviceInput) {
            captureSession.addInput(videoDeviceInput)
        }
        
        if captureSession.canAddInput(audioDeviceInput) {
            captureSession.addInput(audioDeviceInput)
        }
        
        // 获取视频输出设备
        let videoOutput = AVCaptureVideoDataOutput()
        
        let videoQueue = DispatchQueue(label: "Video Capture Queue")
        // 设置代理，捕获视频数据
        videoOutput.setSampleBufferDelegate(self, queue: videoQueue)
        
        // 添加输出对话
        if captureSession.canAddOutput(videoOutput) {
            captureSession.addOutput(videoOutput)
        }
        
        // 获取音频数据输出设备
        let audioOutput = AVCaptureAudioDataOutput()
        let audioQueue = DispatchQueue(label: "Audio Capture Queue")
        // 设置代理获取音频数据
        audioOutput.setSampleBufferDelegate(self, queue: audioQueue)
        
        if captureSession.canAddOutput(audioOutput) {
            captureSession.addOutput(audioOutput)
        }
        
        // 获取视频输入和输出连接，用于分辨音视频数据
        videoConnection = videoOutput.connection(withMediaType: AVMediaTypeVideo)
        
        // 添加视频预览图层
        self.view.layer.insertSublayer(previedLayer, at: 0)
        
        // 启动会话
        captureSession.startRunning()
    }
    
    
    /// 通过指定摄像头方向获取摄像头
    ///
    /// - Parameter position: 方向
    /// - Returns: 摄像头对象
    func getVideoDevice(_ position : AVCaptureDevicePosition) -> AVCaptureDevice? {
        let devices = AVCaptureDevice.devices(withMediaType: AVMediaTypeVideo)
        
        guard  devices != nil else { return nil }
        
        for device in devices! {
            
            if device is AVCaptureDevice {
                if (device as! AVCaptureDevice).position == position {
                    return device as? AVCaptureDevice
                }
            }
        }
        return nil
    }
    
    // 设置聚焦光标出现的位置
    func setFocusCursorWithPoint(_ point : CGPoint) {
        focusImageView.center = point
        focusImageView.transform = CGAffineTransform(scaleX: 1.5, y: 1.5)
        focusImageView.alpha = 1.0
        UIView.animate(withDuration: 1.0, animations: { 
            self.focusImageView.transform = CGAffineTransform(scaleX: 1.0, y: 1.0)
        }) { (_) in
            self.focusImageView.alpha = 0.0
        }
    }
    
    // 聚焦设置
    func setupFocus(focusMode : AVCaptureFocusMode ,exposureMode : AVCaptureExposureMode , point : CGPoint) {

        guard let captureDevice = videoDeviceInput?.device else {
            return
        }
        // 锁定配置
        guard ((try? captureDevice.lockForConfiguration()) != nil) else {
            return
        }
        
        // 设置聚焦
        if captureDevice.isFocusModeSupported(.autoFocus) {
            captureDevice.focusMode = .autoFocus
        }
        
        if captureDevice.isFocusPointOfInterestSupported {
            captureDevice.focusPointOfInterest = point
        }
        
        // 设置曝光
        if captureDevice.isExposureModeSupported(.autoExpose) {
            captureDevice.exposureMode = .autoExpose
        }
        if captureDevice.isExposurePointOfInterestSupported {
            captureDevice.exposurePointOfInterest = point
        }
        
        // 解锁配置
        captureDevice.unlockForConfiguration()
    }
}

// MARK:- 事件监听
extension InformationAcquisitionViewController {
    // 切换摄像头
    @IBAction func clickSwitchCamera(_ sender: UIBarButtonItem) {
        
        // 获取当前设备方向
        let currentPosition = videoDeviceInput?.device.position
        
        // 获取需要改变的方向
        let togglePosition = currentPosition == AVCaptureDevicePosition.back ? AVCaptureDevicePosition.front : AVCaptureDevicePosition.back
        
        // 获取改变的摄像头设备
        guard let toggleDevice = getVideoDevice(togglePosition) else {
            return
        }
        
        // 获取新输入设备
        guard let toggleDeviceInput = try? AVCaptureDeviceInput(device: toggleDevice) else {
            return
        }
        
        // 移出旧摄像头输入设备
        captureSession.removeInput(videoDeviceInput)
        
        // 添加新设备
        captureSession.addInput(toggleDeviceInput)
        
        // 记录该设备
        videoDeviceInput = toggleDeviceInput
    }
    
    // 点击屏幕出现聚焦视图
    override func touchesBegan(_ touches: Set, with event: UIEvent?) {
        // 获取点击位置
        guard let point = ((touches as? NSSet)?.anyObject() as? UITouch)?.location(in: view) else {
            return
        }
        
        // 点击位置转换成摄像头点的位置
        let cameraPoint = previedLayer.captureDevicePointOfInterest(for: point)
        
        // 设置聚焦光标位置
        setFocusCursorWithPoint(point)
        
        // 设置聚焦
        setupFocus(focusMode: .autoFocus, exposureMode: .autoExpose, point: cameraPoint)
    }
}

// MARK:- AVCaptureVideoDataOutputSampleBufferDelegate
extension InformationAcquisitionViewController : AVCaptureVideoDataOutputSampleBufferDelegate,AVCaptureAudioDataOutputSampleBufferDelegate {
    func captureOutput(_ captureOutput: AVCaptureOutput!, didOutputSampleBuffer sampleBuffer: CMSampleBuffer!, from connection: AVCaptureConnection!) {
        if videoConnection == connection {
            print("采集到视频信息")
        } else {
            print("采集到音频信息")
        }
    }
}