视频压缩

最近遇到一个头疼的问题,录制高清视频,上传服务器,但是太大,上传缓慢,经过几天的周折,最后实现了6:1的压缩率,如果您有更好的办法请联系我。

#import "ViewController.h"

#import

#import

#import

@interface ViewController ()

@end

@implementation ViewController{

UIImagePickerController *imagePickerController;

}

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

- (void)touchesBegan:(NSSet*)touches withEvent:(UIEvent *)event{      

 [self showImagePickerForSourceType:UIImagePickerControllerSourceTypeCamera andCameraCaptureMode:UIImagePickerControllerCameraCaptureModeVideo];

}

- (void)showImagePickerForSourceType:(UIImagePickerControllerSourceType)sourceType andCameraCaptureMode:(UIImagePickerControllerCameraCaptureMode)mode{                imagePickerController = [[UIImagePickerController alloc] init];    //这是 VC 的各种 modal 形式    imagePickerController.modalPresentationStyle = UIModalPresentationFullScreen;    imagePickerController.sourceType = sourceType;    //支持的摄制类型,拍照或摄影,此处将本设备支持的所有类型全部获取,并且同时赋值给imagePickerController的话,则可左右切换摄制模式    imagePickerController.mediaTypes = [UIImagePickerController availableMediaTypesForSourceType:UIImagePickerControllerSourceTypeCamera];    imagePickerController.delegate = self;    imagePickerController.videoQuality = UIImagePickerControllerQualityTypeIFrame960x540;    //允许拍照后编辑    imagePickerController.allowsEditing = YES;      

 if (sourceType == UIImagePickerControllerSourceTypeCamera) {        //设置模式-->拍照/摄像        imagePickerController.cameraCaptureMode = mode;        //开启默认摄像头-->前置/后置        imagePickerController.cameraDevice = UIImagePickerControllerCameraDeviceRear;        //设置默认的闪光灯模式-->开/关/自动        imagePickerController.cameraFlashMode = UIImagePickerControllerCameraFlashModeAuto;  

}  

[self presentViewController:imagePickerController animated:YES completion:NULL];

}

#pragma mark delegate

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

NSString *mediaType = info[UIImagePickerControllerMediaType];

if ([mediaType isEqualToString:@"public.image"]) {

NSLog(@"image...");

/*

//获取照片的原图

UIImage* original = [info objectForKey:UIImagePickerControllerOriginalImage];

//获取图片裁剪后,剩下的图

UIImage* crop = [info objectForKey:UIImagePickerControllerCropRect];

//获取图片的url

NSURL* url = [info objectForKey:UIImagePickerControllerMediaURL];

//获取图片的metadata数据信息

NSDictionary* metadata = [info objectForKey:UIImagePickerControllerMediaMetadata];

*/

//获取图片裁剪的图

UIImage* edit = [info objectForKey:UIImagePickerControllerEditedImage];

[self saveImage:edit];

}else{  // public.movie

NSLog(@"video...");

NSURL *url=[info objectForKey:UIImagePickerControllerMediaURL];//视频路径

//        NSString *urlStr=[url path];

//

NSLog(@"开始压缩,压缩前大小 %f MB",[self fileSize:url]);

AVURLAsset *avAsset = [[AVURLAsset alloc] initWithURL:url options:nil];

NSArray *compatiblePresets = [AVAssetExportSession exportPresetsCompatibleWithAsset:avAsset];

if ([compatiblePresets containsObject:AVAssetExportPresetHighestQuality]) {

AVAssetExportSession *exportSession = [[AVAssetExportSession alloc] initWithAsset:avAsset presetName:AVAssetExportPresetHighestQuality];

exportSession.outputURL = [self compressedURL];

//优化网络

exportSession.shouldOptimizeForNetworkUse = true;

//转换后的格式

exportSession.outputFileType = AVFileTypeMPEG4;

//异步导出

[exportSession exportAsynchronouslyWithCompletionHandler:^{

// 如果导出的状态为完成

NSLog(@"%@",exportSession);

if (exportSession.status == AVAssetExportSessionStatusCompleted) {

NSLog(@"压缩完毕,压缩后大小 %f MB",[self fileSize:[self compressedURL]]);

[self saveVideo:[self compressedURL]];

}else{

NSLog(@"当前压缩进度:%f",exportSession.progress);

}

}];

}

//        [self saveVideo:url];

}

[picker dismissViewControllerAnimated:YES completion:nil];

}

- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker{

NSLog(@"取消");

[picker dismissViewControllerAnimated:YES completion:nil];

}

//取消屏幕旋转

- (BOOL)shouldAutorotate {

return YES;

}

#pragma mark save

- (void)saveImage:(UIImage *)img

{

//    //如果是拍照的照片,则需要手动保存到本地,系统不会自动保存拍照成功后的照片

//    UIImageWriteToSavedPhotosAlbum(img, self, @selector(image:didFinishSavingWithError:contextInfo:), nil);

[[[ALAssetsLibrary alloc]init] writeImageToSavedPhotosAlbum:[img CGImage] orientation:(ALAssetOrientation)img.imageOrientation completionBlock:^(NSURL *assetURL, NSError *error) {

if (error) {

NSLog(@"Save image fail:%@",error);

}else{

NSLog(@"Save image succeed.");

}

}];

}

- (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo{

if (error) {

NSLog(@"保存照片过程中发生错误,错误信息:%@",error.localizedDescription);

}else{

NSLog(@"照片保存成功.");

}

}

- (void)video:(NSString *)videoPath didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo

{

NSLog(@"----%@",contextInfo);

if (error) {

NSLog(@"保存视频过程中发生错误,错误信息:%@",error.localizedDescription);

}else{

NSLog(@"视频保存成功.");

}

}

#pragma mark 保存压缩

- (NSURL *)compressedURL

{

return [NSURL fileURLWithPath:[[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, true) lastObject] stringByAppendingPathComponent:[NSString stringWithFormat:@"cgq.mp4"]]];

}

- (CGFloat)fileSize:(NSURL *)path

{

return [[NSData dataWithContentsOfURL:path] length]/1024.00 /1024.00;

}

- (void)saveVideo:(NSURL *)outputFileURL

{

ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];

[library writeVideoAtPathToSavedPhotosAlbum:outputFileURL

completionBlock:^(NSURL *assetURL, NSError *error) {

if (error) {

NSLog(@"保存视频失败:%@",error);

} else {

NSLog(@"保存视频到相册成功");

}

}];

}

@end

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