<图形图像,动画,多媒体> 读书笔记 --- 录制与编辑视频

使用UIImagePickerController 进行录制

#import "ViewController.h"
#import <MobileCoreServices/MobileCoreServices.h>
#import <QuartzCore/QuartzCore.h>

@interface ViewController ()
<UIImagePickerControllerDelegate,UINavigationControllerDelegate>

- (IBAction)videoRecod:(id)sender;


@end

@implementation ViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
	// Do any additional setup after loading the view, typically from a nib.
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (IBAction)videoRecod:(id)sender {
    
    if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
        
        UIImagePickerController *imagePickerController = [[UIImagePickerController alloc] init];
        imagePickerController.delegate = self;
        imagePickerController.sourceType = UIImagePickerControllerSourceTypeCamera;

        imagePickerController.mediaTypes = [[NSArray alloc]
                                            initWithObjects:(NSString *)kUTTypeMovie, nil];
        
        
        //录制质量设定
        imagePickerController.videoQuality = UIImagePickerControllerQualityTypeHigh;
        
        //仅仅同意最多录制30秒时间
        imagePickerController.videoMaximumDuration = 30.0f;
        
        [self presentViewController:imagePickerController animated:YES completion:nil];
        
    } else {
        NSLog(@"摄像头不可用。
");
    }
}


- (void) imagePickerControllerDidCancel: (UIImagePickerController *) picker {
    [self dismissViewControllerAnimated:YES completion:nil];
}

- (void) imagePickerController: (UIImagePickerController *) picker
            didFinishPickingMediaWithInfo: (NSDictionary *) info {
    
    NSURL *url = [info objectForKey:UIImagePickerControllerMediaURL];
    NSString *tempFilePath = [url path];
    
    if ( UIVideoAtPathIsCompatibleWithSavedPhotosAlbum(tempFilePath) ) {
        //video:didFinishSavingWithError:contextInfo: 必须保存成这类回调
        UISaveVideoAtPathToSavedPhotosAlbum( tempFilePath,
                                            self,
                                            @selector(video:didFinishSavingWithError:contextInfo:),
                                            (__bridge void *)(tempFilePath));
    }
    
    [self dismissViewControllerAnimated:YES completion:nil];
    
}


- (void)video:(NSString *)videoPath didFinishSavingWithError:(NSError *)error contextInfo:(NSString *)contextInfo {
    NSString *title; NSString *message;
    if (!error) {
        title = @"视频保存";
        message = @"视频已经保存到设备的相机胶卷中";
    } else {
        title =  @"视频失败";
        message = [error description];
    }
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:title
                                                    message:message
                                                   delegate:nil
                                          cancelButtonTitle:@"OK"
                                          otherButtonTitles:nil];
    [alert show];
}


- (void)navigationController:(UINavigationController *)navigationController
      willShowViewController:(UIViewController *)viewController
                    animated:(BOOL)animated
{
    NSLog(@"选择器将要显示。");
}


- (void)navigationController:(UINavigationController *)navigationController
       didShowViewController:(UIViewController *)viewController
                    animated:(BOOL)animated
{
    NSLog(@"选择器显示结束。
");
}

AVCaptureSession,捕获会话,是为了实现从摄像头和麦克风捕获数据,须要使用AVCaptureSession对象协调输入输出数据

AVCaptureDevice,捕获设备,代表输入一个设备,比如摄像头和麦克风

AVCaptureDeviceInput,捕获会话的一个输入数据源

AVCaptureOutput,捕获会话的一个输出目标,比如输出的视频文件和静态图片

AVCaptureMovieFileOutput,是AVCaptureOutput的子类,通过它能够将捕获的数据输出到QuickTime视频文件里(MOV)

AVCaptureVideoPreviewLayer,是CALayer子类,能够使用它来显示录制的视频

AVCaptureConnection,捕获连接,在一个捕获会话中输入和输出之间的连接

#import "ViewController.h"

#import <AVFoundation/AVFoundation.h>
#import <AssetsLibrary/AssetsLibrary.h>

@interface ViewController ()
    <AVCaptureFileOutputRecordingDelegate>
{
    BOOL isRecording;
}

@property (weak, nonatomic) IBOutlet UILabel *label;
@property (weak, nonatomic) IBOutlet UIButton *button;

@property (strong, nonatomic) AVCaptureSession *session;
@property (strong, nonatomic) AVCaptureMovieFileOutput *output;

- (IBAction)recordPressed:(id)sender;

@end

@implementation ViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    self.session =  [[AVCaptureSession alloc] init];
    self.session.sessionPreset = AVCaptureSessionPresetMedium;
    
    AVCaptureDevice *cameraDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
    
    NSError *error = nil;
    AVCaptureDeviceInput *camera = [AVCaptureDeviceInput deviceInputWithDevice:cameraDevice error:&error];
    
    AVCaptureDevice *micDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeAudio];
    AVCaptureDeviceInput *mic = [AVCaptureDeviceInput deviceInputWithDevice:micDevice error:&error];
    
    if (error || !camera || !mic) {
        NSLog(@"Input Error");
    } else {
        //增加捕获音频视频
        [self.session addInput:camera];
        [self.session addInput:mic];
    }
    
    self.output = [[AVCaptureMovieFileOutput alloc] init];
    
    if ([self.session canAddOutput:self.output]) {
        [self.session addOutput:self.output];//输出
    }
    
    AVCaptureVideoPreviewLayer *previewLayer = [AVCaptureVideoPreviewLayer layerWithSession:self.session];
    previewLayer.frame = CGRectMake(0,0, self.view.frame.size.width, self.view.frame.size.height);
    [self.view.layer insertSublayer:previewLayer atIndex:0];
    
    
    [self.session startRunning];
    isRecording = NO;
    self.label.text = @"";
    
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
}


- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
    if (![self.session isRunning])
    {
        [self.session startRunning];
    }
}

- (void)viewWillDisappear:(BOOL)animated
{
    [super viewWillDisappear:animated];
    if ([self.session isRunning])
    {
        [self.session stopRunning];
    }
}


- (IBAction)recordPressed:(id)sender {
    if (!isRecording)
    {
        [self.button setTitle:@"停止" forState:UIControlStateNormal];
        self.label.text = @"录制中...";
        isRecording = YES;
        NSURL *fileURL = [self fileURL];
        [self.output startRecordingToOutputFileURL:fileURL recordingDelegate:self];
    }
    else
    {
        [self.button setTitle:@"录制" forState:UIControlStateNormal];
        self.label.text = @"停止";
        [self.output stopRecording];
        isRecording = NO;
    }
}

- (NSURL *) fileURL
{
    NSString *outputPath = [[NSString alloc] initWithFormat:@"%@%@", NSTemporaryDirectory(), @"movie.mov"];
    NSURL *outputURL = [[NSURL alloc] initFileURLWithPath:outputPath];
    
    NSFileManager *manager = [[NSFileManager alloc] init];
    if ([manager fileExistsAtPath:outputPath])
    {
        [manager removeItemAtPath:outputPath error:nil];
    }
    
    return outputURL;
}

#pragma  mark-- AVCaptureFileOutputRecordingDelegate托付协议实现方法

- (void)captureOutput:(AVCaptureFileOutput *)captureOutput
    didFinishRecordingToOutputFileAtURL:(NSURL *)outputFileURL
    fromConnections:(NSArray *)connections error:(NSError *)error
{
    
    if (error == nil) {
        ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
        
        [library writeVideoAtPathToSavedPhotosAlbum:outputFileURL
                                    completionBlock:^(NSURL *assetURL, NSError *error)
         {
             if (error)
             {
                 NSLog(@"写入错误。") ;
             }
             
         }];
    }
    
}

使用UIVideoEditorController

#import "ViewController.h"

@interface ViewController ()
<UIVideoEditorControllerDelegate,UINavigationControllerDelegate>

- (IBAction)editButtonPress:(id)sender;

@end

@implementation ViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
	// Do any additional setup after loading the view, typically from a nib.
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (IBAction)editButtonPress:(id)sender {
    
    NSBundle *bundle = [NSBundle mainBundle];
	NSString *moviePath = [bundle pathForResource:@"YY"
                                           ofType:@"mp4"];
    
    //推断设备是否支持编辑视频
    if ([UIVideoEditorController canEditVideoAtPath:moviePath]){
        
        
        UIVideoEditorController *videoEditor =
        [[UIVideoEditorController alloc] init];
        
        videoEditor.delegate = self;
        videoEditor.videoPath = moviePath;
        
        [self presentViewController:videoEditor animated:YES completion:NULL];
        
        
    } else {
        NSLog(@"不能编辑这个视频");
    }
    
}


- (void)videoEditorController:(UIVideoEditorController *)editor
     didSaveEditedVideoToPath:(NSString *)editedVideoPath{
    
    [editor dismissViewControllerAnimated:YES completion:NULL];
    
    
    if ( UIVideoAtPathIsCompatibleWithSavedPhotosAlbum(editedVideoPath) ) {
        UISaveVideoAtPathToSavedPhotosAlbum(editedVideoPath, self,
                                            @selector(video:didFinishSavingWithError:contextInfo:),
                                            (__bridge void *)(editedVideoPath));
    }
}

- (void)videoEditorController:(UIVideoEditorController *)editor
             didFailWithError:(NSError *)error{
    NSLog(@"编辑视频出错");
    NSLog(@"Video editor error occurred = %@", error);
    [editor dismissViewControllerAnimated:YES completion:NULL];
}

- (void)videoEditorControllerDidCancel:(UIVideoEditorController *)editor{
    NSLog(@"视频编辑取消");
    [editor dismissViewControllerAnimated:YES completion:NULL];
}


- (void)video:(NSString *)videoPath
didFinishSavingWithError:(NSError *)error
  contextInfo:(NSString *)contextInfo {
    
    NSString *title; NSString *message;
    if (!error) {
        title = @"视频保存";
        message = @"视频已经保存到设备的相机胶卷中";
    } else {
        title =  @"视频失败";
        message = [error description];
    }
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:title
                                                    message:message
                                                   delegate:nil
                                          cancelButtonTitle:@"OK"
                                          otherButtonTitles:nil];
    [alert show];
}

原书:http://item.jd.com/11522516.html