想实现iPhone手机拍摄一段视频，上传到云端分享给手机好友。

技术实现

视频压缩。iPhone拍摄的视频很大，几秒钟就几十兆文件了，需要做压缩，原来考虑用ffmpeg，安装起来比较复杂，网上也有很多教程，不过在通过appstore审核的时候有一定风险。
首先是点击开始录制的代码：

    if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {

        UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init];

        imagePicker.videoQuality = UIImagePickerControllerQualityTypeIFrame960x540;//视频质量设置

        imagePicker.sourceType = UIImagePickerControllerSourceTypeCamera;

        imagePicker.delegate = self;

        imagePicker.allowsEditing = YES;

        imagePicker.videoMaximumDuration = 300.0f;//设置最长录制5分钟

        imagePicker.mediaTypes = [NSArray arrayWithObject:@"public.movie"];

        [self presentModalViewController:imagePicker animated:YES];

    }
录制完之后的回调方法：

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

{

    NSURL *url = [info objectForKey:UIImagePickerControllerMediaURL];

    NSString *appDocumentPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];

    NSURL *uploadURL = [NSURL fileURLWithPath:[[appDocumentPath stringByAppendingPathComponent:[self dateString]] stringByAppendingString:@".mp4"]];

    // Compress movie first

    [self convertVideoToLowQuailtyWithInputURL:url outputURL:uploadURL];

    [self dismissModalViewControllerAnimated:YES];

    [picker release];

}