Objective C在下载音频时播放 [英] objective c play audio as it is downloading

问题描述

我有一个有关下载和播放音频文件的iphone设计问题.多亏了Matt Gallagher的AudioStreamer示例，我可以流式传输音频并进行播放，但不将其保存在手机上供以后使用.使用NSURLConnection，我可以下载和保存音频文件，但是在data属性为只读的情况下，我必须等到将它们下载后才能初始化我的AVAudioPlayer.我无法添加到缓冲区.

I have an iphone design question regarding downloading and playing an audio file. Thanks to Matt Gallagher's AudioStreamer sample I can stream audio and play it back, bu that does not save it locally on the phone for later. Using an NSURLConnection I can download and save the audio files, but I have to wait until I have downloaded them to init my AVAudioPlayer given the data property is read only. I can not add to the buffer.

我的问题是如何开始下载，但是在足够"下载之后但尚未完成之后才开始播放文件?除了AVAudioPlayer之外，还有其他音频播放器，可以在下载数据时将其馈入其中.

My question is how can I start the download, but then start playing the file after "enough" of it is downloaded, but before it is finished? Is there another audio player other then AVAudioPlayer that I can feed data into as it is being downloaded.

我现在看到的唯一方法是在不同的线程中同时执行这两个操作，但是当然我要拉两次数据.

The only way I can see to do it now would be to do both in different threads, but then of course I would be pulling down the data twice.

有想法吗?

推荐答案

我将使用AVAudioSession和MPMoviePlayerViewController.

I would use an AVAudioSession along with a MPMoviePlayerViewController.

/**
 * Play audio session
 *
 * @version $Revision: 0.1
 */
- (void)playAudioWithURL:(NSString *)audioURL {

    AVAudioSession *audioSession = [AVAudioSession sharedInstance];

    NSError *setCategoryError = nil;
    [audioSession setCategory:AVAudioSessionCategoryPlayback error:&setCategoryError];

    if (setCategoryError) {

    }

    NSError *activationError = nil;
    [audioSession setActive:YES error:&activationError];

    if (activationError) { 

    }

    MPMoviePlayerViewController *tempPlayer = [[MPMoviePlayerViewController alloc]initWithContentURL:[NSURL URLWithString:[audioURL stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]]];

    // Make sure we have airplay
    if([tempPlayer.moviePlayer respondsToSelector:@selector(setAllowsAirPlay:)]) {
        tempPlayer.moviePlayer.allowsAirPlay = YES;
    }

    tempPlayer.moviePlayer.shouldAutoplay = YES;
    tempPlayer.moviePlayer.useApplicationAudioSession = NO;
    [self presentMoviePlayerViewControllerAnimated:tempPlayer];
    [tempPlayer.moviePlayer play];
    [tempPlayer release];

}//end

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