iOS开发之视频播放

1如何播放视频

iOS提供了MPMoviePlayerController、MPMoviePlayerViewController两个类,可以用来轻松播放视频和网络流媒体\网络音频。

提示:网络音频同样使用此控制器播放。YouTobe就是用MPMoviePlayerController实现的。

MPMoviePlayerViewController只能全屏播放视频。

上述两个类都定义在了MediaPlayer框架中,必须手动添加

iOS开发之视频播放

2MPMoviePlayerController支持的格式

n  MPMoviePlayerController

n  继承自NSObject

n  内部有个view可以展示视频内容

n  将该视图添加其他控制器的view上,即可显示视频内容

n  MPMoviePlayerController可以播放的视频格式包括:

n  H.264、MPEG-4等

n  支持的文件扩展名包括:avi,mkv,mov,m4v,mp4等

n  可以从苹果官网:http://support.apple.com/kb/HT1425下载一些用来测试的视频文件,文件都比较小

n  提示:MPMoviePlayerController并不支持所有的视频格式,如果要播放不支持的视频格式,需要借助第三方框架进行解码,如VLC

https://github.com/videolan/vlc

3MPMoviePlayerController的使用

加载视频资源(注意,如果urlnil同样可以加载)

NSAssert(self.url, @"URL不能为空");

[[MPMoviePlayerController alloc] initWithContentURL:self.url];

显示:

[self.view addSubview:self.moviePlayer.view];

通过设置AutoresizingMask属性可以在横竖屏转换时自动调整视图大小

播放:

[self.moviePlayer play];

全屏:

[self.moviePlayer setFullscreen:YES animated:YES];

【备注】MPMoviePlayerController的播放状态是通过通知中心监听的

例如:

#import "MJMoviePlayerViewController.h"

#import <MediaPlayer/MediaPlayer.h>

@interface MJMoviePlayerViewController ()

@property (nonatomic, strong) MPMoviePlayerController *moviePlayer;

@end

@implementation MJMoviePlayerViewController

- (MPMoviePlayerController *)moviePlayer

{

if (!_moviePlayer) {

// 负责控制媒体播放的控制器

NSURL *url =

[[NSBundle mainBundle] URLForResource:@"promo_full.mp4" withExtension:nil];

_moviePlayer =

[[MPMoviePlayerController alloc] initWithContentURL:url];

_moviePlayer.view.frame = self.view.bounds;

_moviePlayer.view.autoresizingMask =

UIViewAutoresizingFlexibleWidth|UIViewAutoresizingFlexibleHeight;

[self.view addSubview:_moviePlayer.view];

}

return _moviePlayer;

}

- (void)viewDidLoad

{

[super viewDidLoad];

[self.moviePlayer play];

}

@end

运行结果:

iOS开发之视频播放

4常用监听通知事件

状态变化:

MPMoviePlayerPlaybackStateDidChangeNotification

播放结束:

MPMoviePlayerPlaybackDidFinishNotification

退出全屏:

MPMoviePlayerDidExitFullscreenNotification

截屏完成:

MPMoviePlayerThumbnailImageRequestDidFinishNotification

截屏方法:

-requestThumbnailImagesAtTimes:timeOption:

例如:

#import "MJMoviePlayerViewController.h"

#import <MediaPlayer/MediaPlayer.h>

@interface MJMoviePlayerViewController ()

@property (nonatomic, strong) MPMoviePlayerController *moviePlayer;

@end

@implementation MJMoviePlayerViewController

- (MPMoviePlayerController *)moviePlayer

{

if (!_moviePlayer) {

// 负责控制媒体播放的控制器

_moviePlayer = [[MPMoviePlayerController alloc] initWithContentURL:self.movieURL];

_moviePlayer.view.frame = self.view.bounds;

_moviePlayer.view.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;

[self.view addSubview:_moviePlayer.view];

}

return _moviePlayer;

}

- (void)viewDidLoad

{

[super viewDidLoad];

[self.moviePlayer play];

[self addNotification];

}

- (void)viewDidAppear:(BOOL)animated

{

self.moviePlayer.fullscreen = YES;

}

#pragma mark - 添加通知

- (void)addNotification

{

// 1. 添加播放状态的监听

NSNotificationCenter *nc = [NSNotificationCenter defaultCenter];

[nc addObserver:self selector:@selector(stateChanged) name:

MPMoviePlayerPlaybackStateDidChangeNotification object:nil];

// 2. 播放完成

[nc addObserver:self selector:@selector(finished) name:

MPMoviePlayerPlaybackDidFinishNotification object:nil];

// 3. 全屏

[nc addObserver:self selector:@selector(finished) name:

MPMoviePlayerDidExitFullscreenNotification object:nil];

// 4. 截屏完成通知

[nc addObserver:self selector:@selector(captureFinished:) name:

MPMoviePlayerThumbnailImageRequestDidFinishNotification object:nil];

// 数组中有多少时间,就通知几次

// MPMovieTimeOptionExact 精确

// MPMovieTimeOptionNearestKeyFrame 大概

[self.moviePlayer requestThumbnailImagesAtTimes:@[@(5.0), @(20.0)] timeOption:MPMovieTimeOptionNearestKeyFrame];

}

- (void)captureFinished:(NSNotification *)notification

{

NSLog(@"%@", notification);

[self.delegate moviePlayerDidCapturedWithImage:notification.userInfo[MPMoviePlayerThumbnailImageKey]];

}

- (void)finished

{

// 1. 删除通知监听

[[NSNotificationCenter defaultCenter] removeObserver:self];

// 2. 返回上级窗体

// 谁申请,谁释放!

[self.delegate moviePlayerDidFinished];

NSLog(@"完成");

}

/**

MPMoviePlaybackStateStopped,           停止

MPMoviePlaybackStatePlaying,           播放

MPMoviePlaybackStatePaused,            暂停

MPMoviePlaybackStateInterrupted,       中断

MPMoviePlaybackStateSeekingForward,    下一个

MPMoviePlaybackStateSeekingBackward    前一个

*/

- (void)stateChanged

{

switch (self.moviePlayer.playbackState) {

case MPMoviePlaybackStatePlaying:

NSLog(@"播放");

break;

case MPMoviePlaybackStatePaused:

NSLog(@"暂停");

break;

case MPMoviePlaybackStateStopped:

// 执行[self.moviePlayer stop]或者前进后退不工作时会触发

NSLog(@"停止");

break;

default:

break;

}

}

@end

上一篇:.NET多线程(Thread,ThreadPool,Task,Async与Await)


下一篇:使用 IntraWeb (41) - 数据控件速查