iOS-音视频采集 by AVFoundation

iOS 11

AR 技术

iOS 8.0

AVFoundation

GPUImage

使用

AVFoundation

完成音视频的采集和显示

主要步骤

// 创建捕捉会话
captureSession = AVCaptureSession()

// 设置视频输入源&输出源
setupVideoInputOutput()

// 设置音频输入源&输出源
setupAudioInputOutput()

// 添加预览图层
setupPreviewLayer()

// 开始采集
captureSession?.startRunning()

// 通过代理获取采集到的音视频 - CMSampleBuffer
captureOutput(_ captureOutput: AVCaptureOutput!, didDrop sampleBuffer: CMSampleBuffer!, from connection: AVCaptureConnection!)

// 切换前后置摄像头
switchCamera()

// 停止采集
captureSession?.stopRunning()

设置视频输入源&输出源

func setupVideoInputOutput() {
// iOS 10.0 +
// let device = AVCaptureDevice.defaultDevice(withDeviceType: AVCaptureDeviceType(rawValue: AVMediaTypeVideo), mediaType: AVMediaTypeVideo, position: .front)

// 取出所有的设备
guard let devices = AVCaptureDevice.devices(withMediaType: AVMediaTypeVideo) as? [AVCaptureDevice] else { return }

// 过滤出前置摄像头
guard let device = devices.filter({ $0.position == .front }).first else { return }
// 创建输入设备
guard let input = try? AVCaptureDeviceInput(device: device) else { return }
self.videoInput = input

// 创建输出设备
let output = AVCaptureVideoDataOutput()
output.setSampleBufferDelegate(self, queue: DispatchQueue.global())
self.videoOutput = output

// 添加输入输出设备
if let session = captureSession {
if session.canAddInput(input) {
session.addInput(input)
}
if session.canAddOutput(output) {
session.addOutput(output)
}
}
}

设置音频输入源&输出源

func setupAudioInputOutput() {
// 取出所有的设备
guard let device = AVCaptureDevice.defaultDevice(withMediaType: AVMediaTypeAudio) else { return }
// 创建输入设备
guard let input = try? AVCaptureDeviceInput(device: device) else { return }

// 创建输入设备
let output = AVCaptureAudioDataOutput()
output.setSampleBufferDelegate(self, queue: DispatchQueue.global())

// 添加输入输出设备
if let session = captureSession {
if session.canAddInput(input) {
session.addInput(input)
}
if session.canAddOutput(output) {
session.addOutput(output)
}
}
}

添加预览图层

func setupPreviewLayer() {
guard let previewLayer = AVCaptureVideoPreviewLayer(session: captureSession) else { return }
previewLayer.frame = view.bounds
self.previewLayer = previewLayer
view.layer.insertSublayer(previewLayer, at: 0)
}

转换摄像头

func switchCamera() {

// 添加切换动画
let rotaionAnim = CATransition()
rotaionAnim.type = "oglFlip"
rotaionAnim.subtype = "fromLeft"
rotaionAnim.duration = 0.25
view.layer.add(rotaionAnim, forKey: nil)

// 获取当前设备的的摄像头方向
guard let videoInput = videoInput else { return }
// 获取当前摄像头方向 并切换
let position: AVCaptureDevicePosition = videoInput.device.position == .front ? .back : .front
guard let devices = (AVCaptureDevice.devices(withMediaType: AVMediaTypeVideo) as? [AVCaptureDevice]) else { return }
guard let device = devices.filter({ $0.position == position }).first else { return }
guard let newInput = try? AVCaptureDeviceInput(device: device) else { return }

/// 开启配置
// 开始配置
captureSession?.beginConfiguration()
captureSession?.removeInput(videoInput)
captureSession?.addInput(newInput)
// 结束配置
captureSession?.commitConfiguration()

// 记录最新的 input
self.videoInput = newInput
}

停止音视频采集

func stopCapturing() {
// 先移除预览视图
self.previewLayer?.removeFromSuperlayer()
// 停止视频采集
captureSession?.stopRunning()
// 置空 session
captureSession = nil
}

获取采集到的音视频

// MARK: - AVCaptureVideoDataOutputSampleBufferDelegate, AVCaptureAudioDataOutputSampleBufferDelegate
extension ViewController: AVCaptureVideoDataOutputSampleBufferDelegate, AVCaptureAudioDataOutputSampleBufferDelegate {
func captureOutput(_ captureOutput: AVCaptureOutput!, didDrop sampleBuffer: CMSampleBuffer!, from connection: AVCaptureConnection!) {
if self.videoOutput?.connection(withMediaType: AVMediaTypeVideo) == connection {
print("采集到视频文件")
} else {
print("采集到音频文件")
}
}
}