Android - 从字节播放 mp3[]
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Android - Playing mp3 from byte[]
提问by nikib3ro
I have my mp3 file in byte[] (downloaded from an service) and I would like to play it on my device similar to how you can play files:
我在 byte[] 中有我的 mp3 文件（从服务下载），我想在我的设备上播放它，类似于播放文件的方式：
MediaPlayer mp = new MediaPlayer();
mp.setDataSource(PATH_TO_FILE);
mp.prepare();
mp.start();
But I can't seem to find a way to do it. I wouldn't mind saving file to phone and then playing it. How can I play the file, or download then play it?
但我似乎找不到办法做到这一点。我不介意将文件保存到手机然后播放。如何播放文件，或下载然后播放？
回答by nikib3ro
OK, thanks to all of you but I needed to play mp3 from byte[] as I get that from .NET webservice (don't wish to store dynamically generated mp3s on server).
好的，谢谢大家，但我需要从 byte[] 播放 mp3，因为我从 .NET webservice 得到它（不想在服务器上存储动态生成的 mp3）。
In the end - there are number of "gotchas" to play simple mp3... here is code for anyone who needs it:
最后 - 有许多“问题”可以播放简单的 mp3 ......这里是任何需要它的人的代码：
private MediaPlayer mediaPlayer = new MediaPlayer();
private void playMp3(byte[] mp3SoundByteArray) {
try {
// create temp file that will hold byte array
File tempMp3 = File.createTempFile("kurchina", "mp3", getCacheDir());
tempMp3.deleteOnExit();
FileOutputStream fos = new FileOutputStream(tempMp3);
fos.write(mp3SoundByteArray);
fos.close();
// resetting mediaplayer instance to evade problems
mediaPlayer.reset();
// In case you run into issues with threading consider new instance like:
// MediaPlayer mediaPlayer = new MediaPlayer();
// Tried passing path directly, but kept getting
// "Prepare failed.: status=0x1"
// so using file descriptor instead
FileInputStream fis = new FileInputStream(tempMp3);
mediaPlayer.setDataSource(fis.getFD());
mediaPlayer.prepare();
mediaPlayer.start();
} catch (IOException ex) {
String s = ex.toString();
ex.printStackTrace();
}
}
EDIT:I've wrote this answer more than 4 years ago - obviously lots of things have changed since then. See Justin's comment on how to reuse MediaPlayer instance. Also, I don't know if .deleteOnExit() will work for you now - feel free to suggest improvement so that temp files do not pile up.
编辑：我在 4 年前写了这个答案 - 显然从那时起很多事情都发生了变化。请参阅 Justin 关于如何重用 MediaPlayer 实例的评论。另外，我不知道 .deleteOnExit() 现在是否适合您 - 请随时提出改进建议，以免临时文件堆积。
回答by Max Vargas
I found an easy solution by encoding my MP3 file as Base64 (I already receive the data encoded from a Restful API service), and then creating a URL object. I tested it in Android 4.1.
我找到了一个简单的解决方案，将我的 MP3 文件编码为 Base64（我已经收到了从 Restful API 服务编码的数据），然后创建一个 URL 对象。我在 Android 4.1 中对其进行了测试。
public void PlayAudio(String base64EncodedString){
try
{
String url = "data:audio/mp3;base64,"+base64EncodedString;
MediaPlayer mediaPlayer = new MediaPlayer();
mediaPlayer.setDataSource(url);
mediaPlayer.prepare();
mediaPlayer.start();
}
catch(Exception ex){
System.out.print(ex.getMessage());
}
}
回答by krishnakumarp
Starting Android MarshMellow (Version Code 23), there is new API that will make this possible.
从 Android MarshMellow（版本代码 23）开始，有新的 API 使这成为可能。
MediaPlayer.setDataSource(android.media.MediaDataSource)
MediaPlayer.setDataSource(android.media.MediaDataSource)
You can provide a custom implementation of MediaDataSource and wrap a byte[]. A basic implementation given below.
您可以提供 MediaDataSource 的自定义实现并包装一个 byte[]。下面给出一个基本的实现。
import android.annotation.TargetApi;
import android.media.MediaDataSource;
import android.os.Build;
import java.io.IOException;
@TargetApi(Build.VERSION_CODES.M)
public class ByteArrayMediaDataSource extends MediaDataSource {
private final byte[] data;
public ByteArrayMediaDataSource(byte []data) {
assert data != null;
this.data = data;
}
@Override
public int readAt(long position, byte[] buffer, int offset, int size) throws IOException {
System.arraycopy(data, (int)position, buffer, offset, size);
return size;
}
@Override
public long getSize() throws IOException {
return data.length;
}
@Override
public void close() throws IOException {
// Nothing to do here
}
}
回答by Yoni Samlan
回答by Dan Alboteanu
If you target API 23 and above, create a class like this
如果您的目标是 API 23 及更高版本，请创建一个这样的类
class MyMediaDataSource(val data: ByteArray) : MediaDataSource() {
override fun readAt(position: Long, buffer: ByteArray, offset: Int, size: Int): Int {
if (position >= data.size) return -1 // -1 indicates EOF
val endPosition: Int = (position + size).toInt()
var size2: Int = size
if (endPosition > data.size)
size2 -= endPosition - data.size
System.arraycopy(data, position.toInt(), buffer, offset, size2)
return size2
}
override fun getSize(): Long {
return data.size.toLong()
}
override fun close() {}
}
and use like this
并像这样使用
val mediaSource = MyMediaDataSource(byteArray)
MediaPlayer().apply {
setAudioStreamType(AudioManager.STREAM_MUSIC)
setDataSource(mediaSource)
setOnCompletionListener { release() }
prepareAsync()
setOnPreparedListener { start() }
}
credits to krishnakumarp's answer above and to this article
归功于上面 krishnakumarp 的回答和这篇文章
回答by subbarao
wrong code:
错误代码：
MediaPlayer mp = new MediaPlayer();
mp.setDataSource(PATH_TO_FILE);
mp.prepare();
mp.start();
CORRECT CODE:
正确的代码：
MediaPlayer mp = new MediaPlayer();
mp.setDataSource(PATH_TO_FILE);
mp.setOnpreparedListener(this);
mp.prepare();
//Implement OnPreparedListener
OnPrepared() {
mp.start();
}
see API Demos ..
见 API 演示 ..
