iOS视频压缩问题

具体操作如下

-(void)handleVideoAccroding:(NSURL *)originFilePath
{
    NSString *cachesPath = [NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES) lastObject];
    NSString *outputPath = [cachesPath stringByAppendingPathComponent:[NSString stringWithFormat:@"fdvideo"]];
    if ([[NSFileManager defaultManager] fileExistsAtPath:outputPath]) {
        [[NSFileManager defaultManager] removeItemAtPath:outputPath error:nil];
    }
    //创建一个由URL标识的代表任何资源的assert对象
    AVURLAsset *asset =  [AVURLAsset URLAssetWithURL:originFilePath options:nil];
    //转码配置   建议选择AVAssetExportPresetMediumQuality
    AVAssetExportSession *exportSession= [[AVAssetExportSession alloc] initWithAsset:asset presetName:AVAssetExportPresetMediumQuality];
    exportSession.shouldOptimizeForNetworkUse = YES;
    //设置视频转码输出路径
    exportSession.outputURL = [NSURL fileURLWithPath:outputPath];
    //AVFileTypeMPEG4 文件输出类型，可以更改，是枚举类型，官方有提供，更改该值也可以改变视频的压缩比例
    exportSession.outputFileType = AVFileTypeMPEG4;
    [exportSession exportAsynchronouslyWithCompletionHandler:^{
        AVAssetExportSessionStatus exportStatus = exportSession.status;
        switch (exportStatus)
        {
            case AVAssetExportSessionStatusFailed:
            {
                NSError *exportError = exportSession.error;
                dispatch_async(dispatch_get_main_queue(), ^{
                    [MBProgressHUD hideHUDForView:self.view animated:YES];
                });
                LHLog(@"转码失败 AVAssetExportSessionStatusFailed: %@", exportError);
                break;
            }
            case AVAssetExportSessionStatusCompleted:
            {
                 LHLog(@"视频转码成功");
                dispatch_async(dispatch_get_main_queue(), ^{
                    NSData *data = [NSData dataWithContentsOfFile:outputPath];
                    [self uploadPhoto:data andInt:0 andCount:self.imagesDataI.count];
               });
            }
                break;
            default:
                dispatch_async(dispatch_get_main_queue(), ^{
                    [MBProgressHUD hideHUDForView:self.view animated:YES];
                });
                break;
        }
    }];
}