目录
一、前言
AVCaptureSession
是 AVFoundation
的核心类
,用于管理捕获
对象 AVCaptureInput 的视频和音频的输入
,协调捕获
的输出 AVCaptureOutput
。
AVCaptureOutput
的输出有两种方法:
- 一种是直接以 movieFileUrl 方式输出;
- 一种是以原始数据流 data 的方式输出
流程对比图如下:
下面详细讲解两种录制视频的方案:
二、方案一:AVCaptureSession + AVCaptureMovieFileOutput
1.创建AVCaptureSession
//导入 AVFoundation.framework
#import <AVFoundation/AVFoundation.h>
//声明属性
@property (nonatomic, strong) AVCaptureSession *captureSession;
//懒加载 AVCapturesession
- (AVCaptureSession *)captureSession {
if (!_captureSession) {
_captureSession = [[AVCaptureSession alloc] init];
//设置分辨率
if ([_captureSession canSetSessionPreset:AVCaptureSessionPresetHigh]) {
[_captureSession setSessionPreset:AVCaptureSessionPresetHigh];
}
}
return _captureSession;
}
注意:AVCaptureSession 的调用是会阻塞线程的,建议单独开辟子线程处理。
2.设置音频、视频输入
//声明属性
@property (nonatomic, strong) AVCaptureDeviceInput *videoInput;
@property (nonatomic, strong) AVCaptureDeviceInput *audioInput;
//设置视频,音频输入源
- (void)setCaptureDeviceInput {
//1. 视频输入源
//获取视频输入设备, 默认后置摄像头
AVCaptureDevice *videoCaptureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
NSError *error = nil;
self.videoInput = [AVCaptureDeviceInput deviceInputWithDevice:videoCaptureDevice error:&error];
if ([self.captureSession canAddInput:self.videoInput]) {
[self.captureSession addInput:self.videoInput];
}
//2. 音频输入源
AVCaptureDevice *audioCaptureDevice = [[AVCaptureDevice devicesWithMediaType:AVMediaTypeAudio] firstObject];
self.audioInput = [AVCaptureDeviceInput deviceInputWithDevice:audioCaptureDevice error:&error];
if ([self.captureSession canAddInput:self.audioInput]) {
[self.captureSession addInput:self.audioInput];
}
}
3.设置文件输出源
//声明属性
@property (nonatomic, strong) AVCaptureMovieFileOutput *movieFileOutput;
@property (nonatomic, strong) AVCaptureVideoPreviewLayer *previewLayer;
//设置文件输出源
- (void)setDeviceFileOutput {
//初始化文件输出对象
self.movieFileOutput = [[AVCaptureMovieFileOutput alloc] init];
//捕获会话中特定捕获输入对象和捕获输出对象之间的连接
AVCaptureConnection *captureConnection = [self.movieFileOutput connectionWithMediaType:AVMediaTypeVideo];
//设置防抖
if ([captureConnection isVideoStabilizationSupported]) {
captureConnection.preferredVideoStabilizationMode = AVCaptureVideoStabilizationModeAuto;
}
//预览图层和视频方向保持一致
captureConnection.videoOrientation = [self.previewLayer connection].videoOrientation;
//添加文件输出源
if ([self.captureSession canAddOutput:self.movieFileOutput]) {
[self.captureSession addOutput:self.movieFileOutput];
}
}
4.添加视频预览层
- (void)setVideoPreviewLayer {
self.previewLayer.frame = [UIScreen mainScreen].bounds;
[self.superView.layer addSubLayer:self.previewLayer];
}
- (AVCaptureVideoPreviewLayer *)previewLayer {
if (!_previewLayer) {
_previewLayer = [AVCaptureVideoPreviewLayer layerWithSession:self.captureSession];
_previewLayer.masksToBounds = YES;
_previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;//填充模式
}
return _previewLayer;
}
5. 开始采集
//声明属性
@propert