录制高清视频，保存低质量视频

Posted 2023-03-08

【中文标题】录制高清视频，保存低质量视频

【英文标题】：Record HD video, save low quality video

【发布时间】：2013-12-14 23:12:20

【问题描述】：

我目前正在使用 UIImagePickerController 录制视频并保存。我使用的是 1080p 质量，所以短视频仍然可以很大。在我的应用程序中，用户可以通过电子邮件发送他们录制的视频，因此拥有大视频是不行的。有什么办法可以保存 2 个版本的视频（高质量和低质量），一个保存在 ~/app-folder/video-name.mov，另一个保存在 ~/app-folder/video-name-SD .mov？或者以某种方式保存高清视频但有一个标清版本？欢迎所有解决方案，而不仅仅是保存 SD 版本。这是我正在做的事情：

  - (BOOL)startCameraControllerFromViewController:(UIViewController *)controller
                                      usingDelegate:(id)delegate 

//setup for video recording
//imagePickerWithout is a subclass of UIImagePicker

        imagePickerWithout *cameraUI = [[imagePickerWithout alloc] init];
        cameraUI.videoQuality = UIImagePickerControllerQualityTypeHigh;

        [controller presentViewController:cameraUI animated:YES completion:nil];
        return YES;
    

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info 

//setup video

        NSURL *videoURL = [info objectForKey:UIImagePickerControllerMediaURL];
        NSData *videoData = [NSData dataWithContentsOfURL:videoURL];

            //pseudocode :(
            NSData *lowQualData = [NSData LOW_QUALITY_VERSION_OF_URL:videoURL];

        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
        NSString *documentsDirectory = [paths objectAtIndex:0];
        int random = arc4random() % 80085;

        NSString *tempPath = [documentsDirectory stringByAppendingPathComponent:[NSString stringWithFormat:@"%@_%@_%@_%d.mov", self.person.first, self.person.last, self.person.age, random]];

NSString *sdPath = [documentsDirectory stringByAppendingPathComponent:[NSString stringWithFormat:@"%@_%@_%@_%dLOWQUAL.mov", self.person.first, self.person.last, self.person.age, random]];

        NSFileManager *fileManager = [NSFileManager defaultManager];

        BOOL success = [videoData writeToFile:tempPath atomically:YES];
            BOOL success = [lowQualData writeToFile:sdPath atomically:YES];

        NSError *error = nil;
        [_managedObjectContext save:&error]

[self dismissViewControllerAnimated:YES completion:nil];

【参考方案1】：

首先以高质量录制视频，然后使用 AVAssetWriter 或 AVAssetExportSession 制作较低质量的副本，如下所述：

iPhone:Programmatically compressing recorded video to share?