iphone - 以 2x 3x 4x 速度播放/转发视频 - iPhone SDK

Question

我想以不同的速度在 MPMoviePlayerController 中播放/转发视频。任何人都可以建议我如何做到这一点。

现在我正在快进（单速），但几秒钟后它又恢复正常速度。

请建议。

Answer 1

MPMoviePlayerController Conforms to MPMediaPlayback protocol 
you can see the property currentPlaybackRate as :-
@property(nonatomic) float currentPlaybackRate 
A value of 0 represents that the video is stopped , a value of 1 indicates normal speed and further positive values indicate increased speed while negative ones indicate reverse .

还要检查你的 MPMediaPlayback 的 endseeing 委托方法，因为它是恢复正常播放的唯一方法

Answer 2

这是 MPMoviePlayerViewController 以 2x 3x 4x 速度前进和后退电影的代码

在 .h 文件中

@property(nonatomic) float currentPlaybackRate;

在 .m 文件中

- (void)viewDidLoad
{
    currentPlaybackRate=1.0; //video Play in Normal speed
}

现在在 FastForward 和 FastBackward 按钮操作

[fastForward addTarget:self action:@selector(fastForward) forControlEvents:UIControlEventTouchUpInside];

[fastBackWard addTarget:self action:@selector(fastBackward) forControlEvents:UIControlEventTouchUpInside];

动作代码

-(void)fastForward
{
    [mp.moviePlayer pause];
    playPauseButton.selected=TRUE;
    if (currentPlaybackRate < 0.0) {
        currentPlaybackRate = 1.0;
    }

    if (currentPlaybackRate < 4.0) {
        currentPlaybackRate=currentPlaybackRate+1.0;
        NSLog(@"Forward::%f",currentPlaybackRate);
        mp.moviePlayer.currentPlaybackRate=currentPlaybackRate;
    }
}
-(void)fastBackward
{
    [mp.moviePlayer pause];
    playPauseButton.selected=TRUE;

    if (currentPlaybackRate > 0.0) {
        currentPlaybackRate = 0.0;
    }


    if (currentPlaybackRate > -4.0) {
        currentPlaybackRate=currentPlaybackRate-1.0;
        NSLog(@"BackWard::%f",currentPlaybackRate);
        mp.moviePlayer.currentPlaybackRate=currentPlaybackRate;
    }
}