在iPhone App中，MPMoviePlayerController以反向（向后）播放电影并不流畅 [英] MPMoviePlayerController playing movies in reverse (backwards) is not smooth in iPhone App

问题描述

我正在开发一个iPhone应用程序，我需要反转视频播放。我目前正在使用XCode 4.2。我正在尝试使用MPMoviePlayerController反向播放电影。
但是当它反向播放时，它并不像播放它那样顺畅。它变得有点波涛汹涌，并不是一帆风顺。以下是我的代码。

I am developing an iPhone application where I need to reverse a video playback. I am currently using XCode 4.2. I am trying to play a movie in reverse with the MPMoviePlayerController. But when it plays in reverse it is not as smooth as playing it forward. It becomes a bit choppy and is not at all smooth. The following is my code.

- (void)viewDidLoad{
//code for initializing the movie player
MPMoviePlayerController videoPlayer = 
[[MPMoviePlayerController alloc] initWithContentURL:"URL"];
self.videoPlayer = videoPlayer;
[videoPlayer release];
self.videoPlayer.view.userInteractionEnabled = NO;
self.videoPlayer.initialPlaybackTime = -1;
self.videoPlayer.shouldAutoplay=NO;
[self.videoPlayer prepareToPlay];


//code for initializing the button 
UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];

[button setTitle:@"Reverse" forState:UIControlStateNormal];

[button addTarget:self 
action:@selector(reverseMovie) forControlEvents:UIControlEventTouchDown];

button.frame = CGRectMake(0, 0, 50, 40);

[self.view addSubview:button];
}

-(void)reverseMovie{
[self.videoPlayer setCurrentPlaybackRate:-1.0];
}

可能的解决办法是什么？

What could be the possible solution to this?

推荐答案

我试图在AVFoundation中做同样的事情。在我设法让它工作之前，我必须工作很多。

I tried to do the same in AVFoundation. I had to work it quite a lot before I managed to get it to work.

我所做的是生成图像，颠倒顺序，将它们放入assetWriter，导出视频然后播放。

What I did was to generate image, reverse the order, put them in to an assetWriter, export the video and then play it.

您可以在此处下载我的代码： https://github.com/mikaelhellqvist/ReverseClip

You can download my code here: https://github.com/mikaelhellqvist/ReverseClip

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