Android中MediaPlayer的速度控制
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Speed Control of MediaPlayer in Android
提问by Krishna Suthar
I am developing a player app and I am using MediaPlayerfor that.
我正在开发一个播放器应用程序，我正在使用MediaPlayer它。
Now, I want to change the speed of the playing track.
现在，我想改变播放曲目的速度。
I've seen so many apps with this functionality. How can I do this?
我见过很多具有此功能的应用程序。我怎样才能做到这一点？
采纳答案by Vipul Shah
The MediaPlayer does notprovide this feature but SoundPool has this functionality.
The SoundPool class has a method called setRate (int streamID, float rate). If you are interested in the API have a look here.
在MediaPlayer的不提供此功能，但拥有的Soundpool此功能。SoundPool 类有一个名为 的方法setRate (int streamID, float rate)。如果您对API感兴趣，请查看此处。
This Snippet will work.
此代码段将起作用。
float playbackSpeed=1.5f;
SoundPool soundPool = new SoundPool(4, AudioManager.STREAM_MUSIC, 100);
soundId = soundPool.load(Environment.getExternalStorageDirectory()
+ "/sample.3gp", 1);
AudioManager mgr = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
final float volume = mgr.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
soundPool.setOnLoadCompleteListener(new OnLoadCompleteListener()
{
@Override
public void onLoadComplete(SoundPool arg0, int arg1, int arg2)
{
soundPool.play(soundId, volume, volume, 1, 0, playbackSpeed);
}
});
回答by Shishir Gupta
Beginning API 23, MediaPlayer can set playback speed using this method.
从 API 23 开始，MediaPlayer 可以使用此方法设置播放速度。
Class MediaPlayer
public void setPlaybackParams (PlaybackParams params)Added in API level 23Sets playback rate using PlaybackParams. Parameters params PlaybackParams: the playback params. Throws IllegalStateException if the internal player engine has not been initialized. IllegalArgumentException if params is not supported.
类媒体播放器
public void setPlaybackParams (PlaybackParams params)在 API 级别 23 中添加使用 PlaybackParams 设置播放速率。参数 params PlaybackParams：播放参数。如果内部播放器引擎尚未初始化，则抛出 IllegalStateException。如果不支持 params，则为 IllegalArgumentException。
Sample code:
示例代码：
MediaPlayer mp = ...; //Whatever
float speed = 0.75f;
mp.setPlaybackParams(mp.getPlaybackParams().setSpeed(speed));
For API < 23, refer to Vipul Shah's answerabove (or below).
对于 API < 23，请参阅上面（或下面）Vipul Shah 的回答。
回答by Bob
soundpool only supports relatively small sound effect files that can be preloaded. You will get heap overflows with any useful length music track.
soundpool 只支持比较小的可以预加载的音效文件。任何有用长度的音乐曲目都会导致堆溢出。
回答by Wallace Zhen
Now you could use
现在你可以使用
mediaPlayer.setPlaybackParams(mediaPlayer.getPlaybackParams().setSpeed(speed)
mediaPlayer.setPlaybackParams(mediaPlayer.getPlaybackParams().setSpeed(speed)
for API 23 and up!
对于 API 23 及更高版本！
回答by Kazekage Gaara
The MediaPlayerclass doesn't give this functionality. Instead use the SoundPoolclass. It has a method called setRate (int streamID, float rate). Read thisfor further info. Here is a sample codefor you to work with it.
本MediaPlayer类不给这个功能。而是使用SoundPool类。它有一个方法叫做setRate (int streamID, float rate). 阅读本文了解更多信息。这是一个示例代码供您使用。
回答by Shailendra Yadav
PlaybackParams playbackParams = new PlaybackParams();
playbackParams.setSpeed(2);
playbackParams.setPitch(1);
playbackParams.setAudioFallbackMode(
PlaybackParams.AUDIO_FALLBACK_MODE_DEFAULT);
mMediaPlayer.setPlaybackParams(playbackParams);
