使用UIImagePickerController系统控制器录制视频时，默认生成的格式是MOV,如果要转成MP4格式的，我们需要使用AVAssetExportSession;
支持转换的视频质量：低，中，高，640*480，720p,1080p等
如下代码片段转换
- (void)mov2mp4:(NSURL *)movUrl { AVURLAsset *avAsset = [AVURLAsset URLAssetWithURL:movUrl options:nil]; NSArray *compatiblePresets = [AVAssetExportSession exportPresetsCompatibleWithAsset:avAsset]; /** AVAssetExportPresetMediumQuality 表示视频的转换质量， */ if ([compatiblePresets containsObject:AVAssetExportPresetMediumQuality]) { AVAssetExportSession *exportSession = [[AVAssetExportSession alloc] initWithAsset:avAsset presetName:AVAssetExportPresetMediumQuality]; //转换完成保存的文件路径 NSString * resultPath = [NSHomeDirectory() stringByAppendingFormat:@"/Documents/output-%@.mp4",@"cvt"]; exportSession.outputURL = [NSURL fileURLWithPath:resultPath]; //要转换的格式，这里使用 MP4 exportSession.outputFileType = AVFileTypeMPEG4; //转换的数据是否对网络使用优化 exportSession.shouldOptimizeForNetworkUse = YES; //异步处理开始转换 [exportSession exportAsynchronouslyWithCompletionHandler:^(void) { //转换状态监控 switch (exportSession.status) { case AVAssetExportSessionStatusUnknown: NSLog(@"AVAssetExportSessionStatusUnknown"); break; case AVAssetExportSessionStatusWaiting: NSLog(@"AVAssetExportSessionStatusWaiting"); break; case AVAssetExportSessionStatusExporting: NSLog(@"AVAssetExportSessionStatusExporting"); break; case AVAssetExportSessionStatusFailed: NSLog(@"AVAssetExportSessionStatusFailed"); break; case AVAssetExportSessionStatusCancelled: NSLog(@"AVAssetExportSessionStatusCancelled"); break; case AVAssetExportSessionStatusCompleted: { //转换完成 NSLog(@"AVAssetExportSessionStatusCompleted"); //测试使用，保存在手机相册里面 ALAssetsLibrary *assetLibrary = [[ALAssetsLibrary alloc] init]; [assetLibrary writeVideoAtPathToSavedPhotosAlbum:exportSession.outputURL completionBlock:^(NSURL *assetURL, NSError *error){ if (error) { NSLog(@"%@",error); } }]; break; } } }]; } }
完整的调用以及转换代码
#import <AssetsLibrary/AssetsLibrary.h> #import <MobileCoreServices/MobileCoreServices.h> #import <AVFoundation/AVFoundation.h> @interface ViewController ()<UIImagePickerControllerDelegate,UINavigationControllerDelegate> @end @implementation ViewController - (void)viewDidLoad { [super viewDidLoad]; } - (IBAction)startCampVD:(id)sender { UIImagePickerController *pickerCon = [[UIImagePickerController alloc]init]; pickerCon.sourceType = UIImagePickerControllerSourceTypeCamera; pickerCon.mediaTypes = @[(NSString *)kUTTypeMovie];//设定相机为视频 pickerCon.cameraDevice = UIImagePickerControllerCameraDeviceFront;//设置相机后摄像头 pickerCon.videoMaximumDuration = 6;//最长拍摄时间 pickerCon.videoQuality = UIImagePickerControllerQualityType640x480;//拍摄质量 pickerCon.allowsEditing = NO;//是否可编辑 pickerCon.delegate = self; [self presentViewController:pickerCon animated:YES completion:nil]; } - (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info { NSLog(@"视频录制完成..."); NSLog(@"%@",info); [self mov2mp4:[info objectForKey:UIImagePickerControllerMediaURL]]; [self dismissViewControllerAnimated:YES completion:nil]; } - (void)mov2mp4:(NSURL *)movUrl { AVURLAsset *avAsset = [AVURLAsset URLAssetWithURL:movUrl options:nil]; NSArray *compatiblePresets = [AVAssetExportSession exportPresetsCompatibleWithAsset:avAsset]; /** AVAssetExportPresetMediumQuality 表示视频的转换质量， */ if ([compatiblePresets containsObject:AVAssetExportPresetMediumQuality]) { AVAssetExportSession *exportSession = [[AVAssetExportSession alloc] initWithAsset:avAsset presetName:AVAssetExportPresetMediumQuality]; //转换完成保存的文件路径 NSString * resultPath = [NSHomeDirectory() stringByAppendingFormat:@"/Documents/output-%@.mp4",@"cvt"]; exportSession.outputURL = [NSURL fileURLWithPath:resultPath]; //要转换的格式，这里使用 MP4 exportSession.outputFileType = AVFileTypeMPEG4; //转换的数据是否对网络使用优化 exportSession.shouldOptimizeForNetworkUse = YES; //异步处理开始转换 [exportSession exportAsynchronouslyWithCompletionHandler:^(void) { //转换状态监控 switch (exportSession.status) { case AVAssetExportSessionStatusUnknown: NSLog(@"AVAssetExportSessionStatusUnknown"); break; case AVAssetExportSessionStatusWaiting: NSLog(@"AVAssetExportSessionStatusWaiting"); break; case AVAssetExportSessionStatusExporting: NSLog(@"AVAssetExportSessionStatusExporting"); break; case AVAssetExportSessionStatusFailed: NSLog(@"AVAssetExportSessionStatusFailed"); break; case AVAssetExportSessionStatusCancelled: NSLog(@"AVAssetExportSessionStatusCancelled"); break; case AVAssetExportSessionStatusCompleted: { //转换完成 NSLog(@"AVAssetExportSessionStatusCompleted"); //测试使用，保存在手机相册里面 ALAssetsLibrary *assetLibrary = [[ALAssetsLibrary alloc] init]; [assetLibrary writeVideoAtPathToSavedPhotosAlbum:exportSession.outputURL completionBlock:^(NSURL *assetURL, NSError *error){ if (error) { NSLog(@"%@",error); } }]; break; } } }]; } } - (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker { [picker dismissViewControllerAnimated:YES completion:^{}]; NSLog(@"视频录制取消了..."); }