AVPlayer音量

playerItem = [[AVPlayerItemalloc] initWithAsset:[AVAssetassetWithURL:[NSURLURLWithString:url]]];

- (void)volumeSet:(UISlider *)slider

{

   NSArray *audioTracks = [_playerItem.assettracksWithMediaType:AVMediaTypeAudio];

    

   NSMutableArray *allAudioParams = [NSMutableArrayarray];

    for (AVAssetTrack *track in audioTracks) {

       AVMutableAudioMixInputParameters *audioInputParams = 

        [AVMutableAudioMixInputParametersaudioMixInputParameters];

        [audioInputParamssetVolume:slider.valueatTime:kCMTimeZero];

        [audioInputParamssetTrackID:[track trackID]];

        [allAudioParamsaddObject:audioInputParams];

    }

    

   AVMutableAudioMix *audioMix = [AVMutableAudioMixaudioMix];

    [audioMix setInputParameters:allAudioParams];

    

    [_playerItemsetAudioMix:audioMix];

}