FFmpeg-iOS获取摄像头麦克风

FFmpeg_allluckly.cn.png

Mac编译ffmpeg获取FFmpeg-iOS
ffmpeg的H.264解码
FFmpeg-iOS推流器的简单封装

今天咱来讲讲在iOS 平台上利用ffmpeg获取到摄像头和麦克风，代码很少，后面再加上iOS 自带的获取摄像头的例子;

FFmpeg获取摄像头麦克风

• 首先导入必要的头文件

#include 
#ifdef __cplusplus
extern "C"
{
#endif
#include 
#include 
#include 
#include 
    
#ifdef __cplusplus
};
#endif

具体代码简单封装了一下，如下：

- (void)showDevice{
    avdevice_register_all();
    AVFormatContext *pFormatCtx = avformat_alloc_context();
    AVDictionary* options = NULL;
    av_dict_set(&options,"list_devices","true",0);
    AVInputFormat *iformat = av_find_input_format("avfoundation");
    printf("==AVFoundation Device Info===\n");
    avformat_open_input(&pFormatCtx,"",iformat,&options);
    printf("=============================\n");
    if(avformat_open_input(&pFormatCtx,"0",iformat,NULL)!=0){
        printf("Couldn't open input stream.\n");
        return ;
    }
    
}

运行一下可以看到日志区域的打印信息如下：

==AVFoundation Device Info===
2017-07-20 16:59:36.325150+0800 LBffmpegDemo[2040:821433] [MC] System group container for systemgroup.com.apple.configurationprofiles path is /private/var/containers/Shared/SystemGroup/systemgroup.com.apple.configurationprofiles
2017-07-20 16:59:36.326529+0800 LBffmpegDemo[2040:821433] [MC] Reading from public effective user settings.
[AVFoundation input device @ 0x145d0100] AVFoundation video devices:
[AVFoundation input device @ 0x145d0100] [0] Back Camera
[AVFoundation input device @ 0x145d0100] [1] Front Camera
[AVFoundation input device @ 0x145d0100] AVFoundation audio devices:
[AVFoundation input device @ 0x145d0100] [0] iPhone 麦克风
=============================
[avfoundation @ 0x153ef800] Selected framerate (29.970030) is not supported by the device
[avfoundation @ 0x153ef800] Supported modes:
[avfoundation @ 0x153ef800]   192x144@[1.000000 30.000000]fps
[avfoundation @ 0x153ef800]   192x144@[1.000000 30.000000]fps
[avfoundation @ 0x153ef800]   352x288@[1.000000 30.000000]fps
[avfoundation @ 0x153ef800]   352x288@[1.000000 30.000000]fps
[avfoundation @ 0x153ef800]   480x360@[1.000000 30.000000]fps
[avfoundation @ 0x153ef800]   480x360@[1.000000 30.000000]fps
[avfoundation @ 0x153ef800]   640x480@[1.000000 30.000000]fps
[avfoundation @ 0x153ef800]   640x480@[1.000000 30.000000]fps
[avfoundation @ 0x153ef800]   960x540@[1.000000 30.000000]fps
[avfoundation @ 0x153ef800]   960x540@[1.000000 30.000000]fps
[avfoundation @ 0x153ef800]   1280x720@[1.000000 30.000000]fps
[avfoundation @ 0x153ef800]   1280x720@[1.000000 30.000000]fps
[avfoundation @ 0x153ef800]   1280x720@[1.000000 60.000000]fps
[avfoundation @ 0x153ef800]   1280x720@[1.000000 60.000000]fps
[avfoundation @ 0x153ef800]   1920x1080@[1.000000 30.000000]fps
[avfoundation @ 0x153ef800]   1920x1080@[1.000000 30.000000]fps
[avfoundation @ 0x153ef800]   2592x1936@[1.000000 20.000000]fps
[avfoundation @ 0x153ef800]   2592x1936@[1.000000 20.000000]fps
[avfoundation @ 0x153ef800]   3264x2448@[1.000000 20.000000]fps
[avfoundation @ 0x153ef800]   3264x2448@[1.000000 20.000000]fps
Couldn't open input stream.

显然获取到了我们的设备，前后摄像头，和麦克风；下面我们看看系统自带的获取摄像头的例子：

iOS系统自带获取摄像头

• 首先导入必须的头文件

#import 
#import 

• 然后是一些全局的属性

@property(nonatomic, strong) AVCaptureSession                *captureSession;
@property(nonatomic, strong) AVCaptureDevice                 *captureDevice;
@property(nonatomic, strong) AVCaptureDeviceInput            *captureDeviceInput;
@property(nonatomic, strong) AVCaptureVideoDataOutput        *captureVideoDataOutput;
@property(nonatomic, assign) CGSize                          videoSize;
@property(nonatomic, strong) AVCaptureConnection             *videoCaptureConnection;
@property(nonatomic, strong) AVCaptureVideoPreviewLayer      *previewLayer;

• 最后是简单封装的代码

- (void)getMovieDevice:(UIView *)view{
    self.captureSession = [[AVCaptureSession alloc] init];
    //    captureSession.sessionPreset = AVCaptureSessionPresetMedium;
    self.captureSession.sessionPreset = AVCaptureSessionPreset1920x1080;
    
    self.videoSize = [self getVideoSize:self.captureSession.sessionPreset];
    
    self.captureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
    
    NSError *error = nil;
    self.captureDeviceInput = [AVCaptureDeviceInput deviceInputWithDevice:self.captureDevice error:&error];
    
    if([self.captureSession canAddInput:self.captureDeviceInput])
        [self.captureSession addInput:self.captureDeviceInput];
    else
        NSLog(@"Error: %@", error);
    
    dispatch_queue_t queue = dispatch_queue_create("myEncoderH264Queue", NULL);
    
    self.captureVideoDataOutput = [[AVCaptureVideoDataOutput alloc] init];
    [self.captureVideoDataOutput setSampleBufferDelegate:self queue:queue];
    
#if encodeModel
    // nv12
    NSDictionary *settings = [[NSDictionary alloc] initWithObjectsAndKeys:
                              [NSNumber numberWithUnsignedInt:kCVPixelFormatType_420YpCbCr8BiPlanarFullRange],
                              kCVPixelBufferPixelFormatTypeKey,
                              nil];
#else
    // 32bgra
    NSDictionary *settings = [[NSDictionary alloc] initWithObjectsAndKeys:
                              [NSNumber numberWithUnsignedInt:kCVPixelFormatType_32BGRA],
                              kCVPixelBufferPixelFormatTypeKey,
                              nil];
#endif
    
    self.captureVideoDataOutput.videoSettings = settings;
    self.captureVideoDataOutput.alwaysDiscardsLateVideoFrames = YES;
    
    if ([self.captureSession canAddOutput:self.captureVideoDataOutput]) {
        [self.captureSession addOutput:self.captureVideoDataOutput];
    }
    
    // 保存Connection，用于在SampleBufferDelegate中判断数据来源（是Video/Audio？）
    self.videoCaptureConnection = [self.captureVideoDataOutput connectionWithMediaType:AVMediaTypeVideo];
    
#pragma mark -- AVCaptureVideoPreviewLayer init
    self.previewLayer = [AVCaptureVideoPreviewLayer layerWithSession:self.captureSession];
    self.previewLayer.frame = view.layer.bounds;
    self.previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill; // 设置预览时的视频缩放方式
    [[self.previewLayer connection] setVideoOrientation:AVCaptureVideoOrientationPortrait]; // 设置视频的朝向
    [self.captureSession startRunning];
    [view.layer addSublayer:self.previewLayer];
}

- (CGSize)getVideoSize:(NSString *)sessionPreset {
    CGSize size = CGSizeZero;
    if ([sessionPreset isEqualToString:AVCaptureSessionPresetMedium]) {
        size = CGSizeMake(480, 360);
    } else if ([sessionPreset isEqualToString:AVCaptureSessionPreset1920x1080]) {
        size = CGSizeMake(1920, 1080);
    } else if ([sessionPreset isEqualToString:AVCaptureSessionPreset1280x720]) {
        size = CGSizeMake(1280, 720);
    } else if ([sessionPreset isEqualToString:AVCaptureSessionPreset640x480]) {
        size = CGSizeMake(640, 480);
    }
    
    return size;
}

#pragma mark --  AVCaptureVideo(Audio)DataOutputSampleBufferDelegate method
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection
{
    
    // 这里的sampleBuffer就是采集到的数据了，但它是Video还是Audio的数据，得根据connection来判断
    if (connection == self.videoCaptureConnection) {
        
        // Video
        //        NSLog(@"在这里获得video sampleBuffer，做进一步处理（编码H.264）");
        
        
#if encodeModel
        // encode
        
#else
        CVPixelBufferRef pixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
        
        //        int pixelFormat = CVPixelBufferGetPixelFormatType(pixelBuffer);
        //        switch (pixelFormat) {
        //            case kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange:
        //                NSLog(@"Capture pixel format=NV12");
        //                break;
        //            case kCVPixelFormatType_422YpCbCr8:
        //                NSLog(@"Capture pixel format=UYUY422");
        //                break;
        //            default:
        //                NSLog(@"Capture pixel format=RGB32");
        //                break;
        //        }
        
        CVPixelBufferLockBaseAddress(pixelBuffer, 0);
        
        // render
        [openglView render:pixelBuffer];
        
        CVPixelBufferUnlockBaseAddress(pixelBuffer, 0);
#endif
    }
    //    else if (connection == _audioConnection) {
    //        
    //        // Audio
    //        NSLog(@"这里获得audio sampleBuffer，做进一步处理（编码AAC）");
    //    }
    
}

LBffmpegDemo下载地址

到此iOS平台获取摄像头告一段落，有时间再慢慢写FFmpeg在iOS平台的一些其他的使用方法；有对ffmpeg感兴趣的朋友可以关注我！

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