話不多說,上 DEMO 這裡用的是 SVProressHUD, 由於 iOS10 的權限緣故,需要在 plist 裡添加字段,否則會崩潰,具體請看上一篇

//
//  ViewController.m
//  錄制視頻
//
//  Created by Amydom on 16/8/25.
//  Copyright © 2016年 Amydom. All rights reserved.
//

#import "ViewController.h"
#import 
#import 
#import 

#import 
#import 
#import 
#import 

#import "SVProgressHUD.h"

static NSString *const AssetCollectionName = @"錄制視頻";
@interface ViewController ()
@property (weak, nonatomic) UIImageView *centerFrameImageView;
@property (weak, nonatomic)  UILabel *videoDurationLabel;
@property (nonatomic, assign) BOOL shouldAsync;


@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    [self createBtn];
#pragma mark - 視頻相關
    /*
     一.保存圖片到【Camera Roll】(相機膠卷)
     1.使用函數UIImageWriteToSavedPhotosAlbum
     2.使用AssetsLibrary.framework(iOS9開始, 已經過期)
     3.使用Photos.framework(iOS8開始可以使用, 從iOS9開始完全取代AssetsLibrary.framework)
     
     二.創建新的【自定義Album】(相簿\相冊)
     1.使用AssetsLibrary.framework(iOS9開始, 已經過期)
     2.使用Photos.framework(iOS8開始可以使用, 從iOS9開始完全取代AssetsLibrary.framework)
     
     三.將【Camera Roll】(相機膠卷)的圖片 添加到 【自定義Album】(相簿\相冊)中
     1.使用AssetsLibrary.framework(iOS9開始, 已經過期)
     2.使用Photos.framework(iOS8開始可以使用, 從iOS9開始完全取代AssetsLibrary.framework)
     
     四.Photos.framework須知
     1.PHAsset : 一個PHAsset對象就代表一張圖片或者一段視頻
     2.PHAssetCollection : 一個PHAssetCollection對象就代表一本相冊
     
     五.PHAssetChangeRequest的基本認識
     1.可以對相冊圖片進行【增\刪\改】的操作
     
     六.PHPhotoLibrary的基本認識
     1.對相冊的任何修改都必須放在以下其中一個方法的block中
     [[PHPhotoLibrary sharedPhotoLibrary] performChangesAndWait:error:];
     [[PHPhotoLibrary sharedPhotoLibrary] performChanges:completionHandler:];
     */

    
}

- (void)createBtn{
    
    // 錄制視頻
    UIButton *RecordVideo = [[UIButton alloc]initWithFrame:CGRectMake(100, 100, 100, 100)];
    [RecordVideo setTitle:@"開始錄制" forState:UIControlStateNormal];
    RecordVideo.backgroundColor = [UIColor lightGrayColor];
    [RecordVideo addTarget:self action:@selector(videoFromcamera) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:RecordVideo];
    
    // 從選擇視頻
    UIButton *SelectLocalVideo = [[UIButton alloc]initWithFrame:CGRectMake(100, 250, 100, 100)];
    [SelectLocalVideo setTitle:@"選擇視頻" forState:UIControlStateNormal];
    SelectLocalVideo.backgroundColor = [UIColor lightGrayColor];
    [SelectLocalVideo addTarget:self action:@selector(videoFromPhotos) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:SelectLocalVideo];
}

// 錄制視頻
- (void)videoFromcamera{
        [self getVideoWithsourceType:UIImagePickerControllerSourceTypeCamera shouldAsync:YES];
    
}

// 從相冊中選擇視頻"
- (void)videoFromPhotos{
    //UIImagePickerControllerSourceTypeSavedPhotosAlbum - 這個是自定義庫，是由用戶截圖或保存到裡面的
        [self getVideoWithsourceType:UIImagePickerControllerSourceTypeSavedPhotosAlbum shouldAsync:NO];
}
//調用攝像頭
- (void)getVideoWithsourceType:(UIImagePickerControllerSourceType)type shouldAsync:(BOOL)shouldAsync{
    //取得授權狀態
    AVAuthorizationStatus authStatus = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo];
    //判斷當前狀態
    if (authStatus == AVAuthorizationStatusRestricted
        || authStatus == AVAuthorizationStatusDenied) {
        //拒絕當前 app 訪問[phtot]運行
        [SVProgressHUD showInfoWithStatus:@"提醒用戶打開訪問開關 [設置] - [隱私] - [視頻] - [App]"];
        return;
    }
    
    if ([UIImagePickerController isSourceTypeAvailable:type]) {
        UIImagePickerController *picker = [[UIImagePickerController alloc]init];
        picker.delegate = self;
        //可以編輯
        picker.allowsEditing = YES;
        //設置資源獲取類型
        picker.sourceType = type;
        picker.mediaTypes = @[(NSString *)kUTTypeMovie];
        [self presentViewController:picker animated:YES completion:NULL];
        self.shouldAsync = shouldAsync;
        
    }else{
        
        [SVProgressHUD showInfoWithStatus:@"手機不支持攝像"];
        
    }
}
#pragma mark - UIImagePickerControllerDelegate

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info{
    //獲取媒體 Url
    NSURL * VideoUrl = [info objectForKey:UIImagePickerControllerMediaURL];
    //判斷版本號
    if ([UIDevice currentDevice].systemVersion.doubleValue < 9.0) {
        ALAssetsLibrary * library = [[ALAssetsLibrary alloc]init];
        //創建並行隊列
        dispatch_async(dispatch_get_global_queue(0, 0), ^{
            //判斷相冊時候兼容視頻,兼容才能保存到相冊
            if ([library videoAtPathIsCompatibleWithSavedPhotosAlbum:VideoUrl]) {
                [library writeVideoAtPathToSavedPhotosAlbum:VideoUrl completionBlock:^(NSURL *assetURL, NSError *error) {
                    
                    dispatch_async(dispatch_get_main_queue(), ^{
                        //回到主線程,寫入相冊
                        if (error == nil) {
                            AVURLAsset *videoAsset = [[AVURLAsset alloc]initWithURL:assetURL options:nil];
                            Float64 duration = CMTimeGetSeconds(videoAsset.duration);
                            self.videoDurationLabel.text = [NSString stringWithFormat:@"視頻時長: %.0f秒",duration];
                            if (_shouldAsync) {
                                __weak __typeof(self)weakSelf = self;
                                // Get center frame image asyncly
                                [weakSelf centerFrameImageWithVideoURL:VideoUrl completion:^(UIImage *image) {
                                    
                                    weakSelf.centerFrameImageView.image = image;
                                    
                                }];
                                
                            } else {
                                
                                //同步獲取中間幀圖片
                                UIImage * image = [self frameImageFromVideoURL:VideoUrl];
                                self.centerFrameImageView.image = image;
                            }
                            
                            // Begin to compress and export the video to the output path
                            // 開始壓縮和導出視頻輸出路徑
                            NSString * name = [[NSDate date] description];
                            name = [NSString stringWithFormat:@"%@.mp4", name];
                            [self compressVideoWithVideoURL:VideoUrl savedName:name completion:^(NSString *savedPath) {
                                
                                if (savedPath) {
                                    
                                     NSLog(@"Compressed successfully. path: %@", savedPath);
                                } else {
                                    
                                    NSLog(@"Compressed failed");
                                }
                            }];
                            
                            [SVProgressHUD showInfoWithStatus:@"保存視頻失敗"];
                            
                        } else {
                            
                            [SVProgressHUD showInfoWithStatus:@"保存視頻成功"];
                        }
                        
                    });
                    
                    
                }];
                
            }
            
        });
        
    }else{
        //9.0以後
        PHPhotoLibrary * library = [PHPhotoLibrary sharedPhotoLibrary];
        dispatch_async(dispatch_get_main_queue(), ^{
            
            NSError * error = nil;
            // 用來抓取PHAsset的字符串標識
            __block NSString *assetId = nil;
            // 用來抓取PHAssetCollectin的字符串標識符
            __block NSString *assetCollectionId = nil;
            
            // 保存視頻到【Camera Roll】(相機膠卷)
            
            [library performChangesAndWait:^{
                
                assetId = [PHAssetChangeRequest creationRequestForAssetFromVideoAtFileURL:VideoUrl].placeholderForCreatedAsset.localIdentifier;
                
            } error:&error];
            // 獲取曾經創建過的自定義視頻相冊名字
            PHAssetCollection  * createdAssetCollection = nil;
            PHFetchResult< PHAssetCollection *>* assetCollections = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeAlbum subtype:PHAssetCollectionSubtypeAlbumRegular options:nil];
            for (PHAssetCollection * assetCollection in assetCollections) {
                if ([assetCollection.localizedTitle isEqualToString: AssetCollectionName]) {
                    
                    createdAssetCollection = assetCollection;
                    
                    break;
                    
                }
            }
            
            //如果這個自定義框架沒有創建過
            if (createdAssetCollection == nil) {
                //創建新的[自定義的 Album](相簿\相冊)
                [library performChangesAndWait:^{
                    
                    assetCollectionId = [PHAssetCollectionChangeRequest creationRequestForAssetCollectionWithTitle:AssetCollectionName].placeholderForCreatedAssetCollection.localIdentifier;
                    
                    
                } error:&error];
                
                //抓取剛創建完的視頻相冊對象
                createdAssetCollection = [PHAssetCollection fetchAssetCollectionsWithLocalIdentifiers:@[assetCollectionId] options:nil].firstObject;
            }
            
             // 將【Camera Roll】(相機膠卷)的視頻 添加到 【自定義Album】(相簿\相冊)中
            [library performChangesAndWait:^{
                PHAssetCollectionChangeRequest *request = [PHAssetCollectionChangeRequest changeRequestForAssetCollection:createdAssetCollection];
                
                // 視頻
                [request addAssets:[PHAsset fetchAssetsWithLocalIdentifiers:@[assetId] options:nil]];
            } error:&error];
            
            // 提示信息
            if (error) {
                [SVProgressHUD showErrorWithStatus:@"保存視頻失敗!"];
            } else {
                [SVProgressHUD showSuccessWithStatus:@"保存視頻成功!"];
            }

        });
        
        
    }
    
    [picker dismissViewControllerAnimated:YES completion:^{
        // for fixing iOS 8.0 problem that frame changed when open camera to record video.
        self.tabBarController.view.frame  = [[UIScreen mainScreen] bounds];
        [self.tabBarController.view layoutIfNeeded];
    }];
    
}
#pragma mark - 同步獲取幀圖
// Get the video's center frame as video poster image
- (UIImage *)frameImageFromVideoURL:(NSURL *)videoURL {
    // result
    UIImage *image = nil;
    
    // AVAssetImageGenerator
    AVAsset *asset = [AVAsset assetWithURL:videoURL];
    AVAssetImageGenerator *imageGenerator = [[AVAssetImageGenerator alloc] initWithAsset:asset];
    imageGenerator.appliesPreferredTrackTransform = YES;
    
    // calculate the midpoint time of video
    Float64 duration = CMTimeGetSeconds([asset duration]);
    // 取某個幀的時間，參數一表示哪個時間（秒），參數二表示每秒多少幀
    // 通常來說，600是一個常用的公共參數，蘋果有說明:
    // 24 frames per second (fps) for film, 30 fps for NTSC (used for TV in North America and
    // Japan), and 25 fps for PAL (used for TV in Europe).
    // Using a timescale of 600, you can exactly represent any number of frames in these systems
    CMTime midpoint = CMTimeMakeWithSeconds(duration / 2.0, 600);
    
    // get the image from
    NSError *error = nil;
    CMTime actualTime;
    // Returns a CFRetained CGImageRef for an asset at or near the specified time.
    // So we should mannully release it
    CGImageRef centerFrameImage = [imageGenerator copyCGImageAtTime:midpoint
                                                         actualTime:&actualTime
                                                              error:&error];
    
    if (centerFrameImage != NULL) {
        image = [[UIImage alloc] initWithCGImage:centerFrameImage];
        // Release the CFRetained image
        CGImageRelease(centerFrameImage);
    }
    
    return image;
}

#pragma mark - 異步獲取幀圖
//異步獲取幀圖,可以一次回去多幀圖片
- (void)centerFrameImageWithVideoURL:(NSURL *)videoURL completion:(void (^)(UIImage *image))completion{
    
    // AVAssetImageGenerator
    AVAsset * asset = [AVAsset assetWithURL:videoURL];
    AVAssetImageGenerator *imageGenerator = [[AVAssetImageGenerator alloc]initWithAsset:asset];
    imageGenerator.appliesPreferredTrackTransform = YES;
    // calculate the midpoint time of video
    Float64 duration = CMTimeGetSeconds([asset duration]);
    
    // 取某個幀的時間，參數一表示哪個時間（秒），參數二表示每秒多少幀
    // 通常來說，600是一個常用的公共參數，蘋果有說明:
    // 24 frames per second (fps) for film, 30 fps for NTSC (used for TV in North America and
    // Japan), and 25 fps for PAL (used for TV in Europe).
    // Using a timescale of 600, you can exactly represent any number of frames in these systems
    
    CMTime midpoint = CMTimeMakeWithSeconds(duration / 2.0, 600);
    //異步獲取多幀圖
    NSValue * midTime = [NSValue valueWithCMTime:midpoint];
    [imageGenerator generateCGImagesAsynchronouslyForTimes:@[midTime] completionHandler:^(CMTime requestedTime, CGImageRef  _Nullable image, CMTime actualTime, AVAssetImageGeneratorResult result, NSError * _Nullable error) {
        
        if (result == AVAssetImageGeneratorSucceeded && image != NULL) {
            UIImage * centerFrameImage = [[UIImage alloc]initWithCGImage:image];
            dispatch_async(dispatch_get_main_queue(), ^{
                
                if (completion) {
                    
                    completion(centerFrameImage);
                    
                }
                
            });
            
        } else {
            
            dispatch_async(dispatch_get_main_queue(), ^{
                
                if (completion) {
                    completion(nil);
                }
            });
            
            
        }
        
    }];
  
}

#pragma mark - 壓縮導出視頻
- (void)compressVideoWithVideoURL:(NSURL *)videoURL
                        savedName:(NSString *)savedName
                       completion:(void (^)(NSString *savedPath))completion{
    
    // Accessing video by URL
    AVURLAsset *videoAsset = [[AVURLAsset alloc] initWithURL:videoURL options:nil];
    // Find compatible presets by video asset.
    NSArray *presets = [AVAssetExportSession exportPresetsCompatibleWithAsset:videoAsset];
    // Begin to compress video
    // Now we just compress to low resolution if it supports
    // If you need to upload to the server, but server does't support to upload by streaming,
    // You can compress the resolution to lower. Or you can support more higher resolution.
    //開始壓縮視頻
    //現在我們壓縮到低分辨率是否支持
    //如果需要上傳服務器,但由流媒體服務器不支持上傳,
    //可以壓縮分辨率降低。或者你可以支持更多的高分辨率。
    if ([presets containsObject:AVAssetExportPreset640x480]) {
        AVAssetExportSession * session = [[AVAssetExportSession alloc]initWithAsset:videoAsset presetName:AVAssetExportPreset640x480];
        //NSHomeDirectory()  得到的是應用程序目錄的路徑，在該目錄下有三個文件夾：Documents、Library、temp以及一個.app包！該目錄下就是應用程序的沙盒，應用程序只能訪問該目錄下的文件夾！！！
        NSString * doc = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents"];
        
        NSString * folder = [doc stringByAppendingPathComponent:@"錄制視頻"];
        BOOL isDir = NO;
        BOOL isExist = [[NSFileManager defaultManager] fileExistsAtPath:folder isDirectory:&isDir];
        if (!isExist || (isExist && !isDir)) {
            
            NSError * error = nil;
            
            [[NSFileManager defaultManager]createDirectoryAtPath:folder withIntermediateDirectories:YES attributes:nil error:&error];
            if (error == nil) {
                [SVProgressHUD showInfoWithStatus:@"目錄創建成功"];
            } else {
                [SVProgressHUD showInfoWithStatus:@"目錄創建失敗"];
                
            }
        }
        
        NSString * OutPutPath = [folder stringByAppendingPathComponent:savedName];
        session.outputURL = [NSURL fileURLWithPath:OutPutPath];
        // Optimize for network use.
        session.shouldOptimizeForNetworkUse = true;
        
        NSArray * supportedTypeArray = session.supportedFileTypes;
        if ([supportedTypeArray containsObject:AVFileTypeMPEG4]) {
            session.outputFileType = AVFileTypeMPEG4;
            
        } else if (supportedTypeArray.count == 0){
            
            [SVProgressHUD showInfoWithStatus:@"No supported file types"];
            return;
            
        } else {
            
            session.outputFileType = [supportedTypeArray objectAtIndex:0];
            
        }
        
        // Begin to export video to the output path asynchronously.
        //開始出口異步視頻輸出路徑。
        [session exportAsynchronouslyWithCompletionHandler:^{
            
            if ([session status] == AVAssetExportSessionStatusCompleted) {
                
                dispatch_async(dispatch_get_main_queue(), ^{
                    
                    if (completion) {
                        
                        completion([session.outputURL path
                                    ]);
                        
                    }
                    
                });
                
            } else {
                
                dispatch_async(dispatch_get_main_queue(), ^{
                    
                    if (completion) {
                        completion(nil);
                    }
                    
                });
                
            }
            
        }];
        
    }
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}
#pragma mark - 相關屬性參數
/**
 *  (1)代理
 delegate
 
 (2)幾個基本屬性設置
 sourceType  //設置資源獲取類型
 allowsEditing   //是否允許圖片編輯
 
 (3)幾個判斷類方法
 *是否可以獲取該類型資源
+ (BOOL)isSourceTypeAvailable:(UIImagePickerControllerSourceType)sourceType;

*是否可以獲取該類型相機（前置和後置 ）
+ (BOOL)isCameraDeviceAvailable:(UIImagePickerControllerCameraDevice)cameraDevice;

*是否可以獲取閃光燈
+ (BOOL)isFlashAvailableForCameraDevice:(UIImagePickerControllerCameraDevice)cameraDevice;

(4)代理方法（iOS4後僅存2個可用）
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info;
- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker;
* 參數info中的鍵
NSString *const  UIImagePickerControllerMediaType ;指定用戶選擇的媒體類型（文章最後進行擴展）
NSString *const  UIImagePickerControllerOriginalImage ;原始圖片
NSString *const  UIImagePickerControllerEditedImage ;修改後的圖片
NSString *const  UIImagePickerControllerCropRect ;裁剪尺寸
NSString *const  UIImagePickerControllerMediaURL ;媒體的URL
NSString *const  UIImagePickerControllerReferenceURL ;原件的URL
NSString *const  UIImagePickerControllerMediaMetadata;當來數據來源是照相機的時候這個值才有效

* UIImagePickerControllerMediaType
UIImagePickerControllerMediaType 包含著KUTTypeImage 和KUTTypeMovie
KUTTypeImage 包含：
const CFStringRef  kUTTypeImage ;抽象的圖片類型
const CFStringRef  kUTTypeJPEG ;
const CFStringRef  kUTTypeJPEG2000 ;
const CFStringRef  kUTTypeTIFF ;
const CFStringRef  kUTTypePICT ;
const CFStringRef  kUTTypeGIF ;
const CFStringRef  kUTTypePNG ;
const CFStringRef  kUTTypeQuickTimeImage ;
const CFStringRef  kUTTypeAppleICNS
const CFStringRef kUTTypeBMP;
const CFStringRef  kUTTypeICO;

KUTTypeMovie 包含：
const CFStringRef  kUTTypeAudiovisualContent ;抽象的聲音視頻
const CFStringRef  kUTTypeMovie ;抽象的媒體格式（聲音和視頻）
const CFStringRef  kUTTypeVideo ;只有視頻沒有聲音
const CFStringRef  kUTTypeAudio ;只有聲音沒有視頻
const CFStringRef  kUTTypeQuickTimeMovie ;
const CFStringRef  kUTTypeMPEG ;
const CFStringRef  kUTTypeMPEG4 ;
const CFStringRef  kUTTypeMP3 ;
const CFStringRef  kUTTypeMPEG4Audio ;
const CFStringRef  kUTTypeAppleProtectedMPEG4Audio;
 */

@end