我在我的应用程序中有一个流媒体URL,我也记录了相同的文件以便离线听取。我能够通过媒体播放器和服务来流式传输URL,但现在我正在寻找相同文件的录制逻辑。
我该如何录制实时流并将文件保存到SD卡上?
我在我的应用程序中有一个流媒体URL,我也记录了相同的文件以便离线听取。我能够通过媒体播放器和服务来流式传输URL,但现在我正在寻找相同文件的录制逻辑。
我该如何录制实时流并将文件保存到SD卡上?
从上面的链接中,您可以使用StreamingMediaPlayer。原始的Android MediaPlayer尚不支持从外部URL进行流媒体传输,因此此类通过逐步下载内容并在我们的临时存储中获取足够的音频后立即播放提供了伪流媒体功能。
public class StreamingMediaPlayer {
private static final int INTIAL_KB_BUFFER = 96*10/8;//assume 96kbps*10secs/8bits per byte
private TextView textStreamed;
private ImageButton playButton;
private ProgressBar progressBar;
// Track for display by progressBar
private long mediaLengthInKb, mediaLengthInSeconds;
private int totalKbRead = 0;
// Create Handler to call View updates on the main UI thread.
private final Handler handler = new Handler();
private MediaPlayer mediaPlayer;
private File downloadingMediaFile;
private boolean isInterrupted;
private Context context;
private int counter = 0;
public StreamingMediaPlayer(Context context,TextView textStreamed, ImageButton playButton, Button streamButton,ProgressBar progressBar)
{
this.context = context;
this.textStreamed = textStreamed;
this.playButton = playButton;
this.progressBar = progressBar;
}
/**
* Progressivly download the media to a temporary location and update the MediaPlayer as new content becomes available.
*/
public void startStreaming(final String mediaUrl, long mediaLengthInKb, long mediaLengthInSeconds) throws IOException {
this.mediaLengthInKb = mediaLengthInKb;
this.mediaLengthInSeconds = mediaLengthInSeconds;
Runnable r = new Runnable() {
public void run() {
try {
downloadAudioIncrement(mediaUrl);
} catch (IOException e) {
Log.e(getClass().getName(), "Unable to initialize the MediaPlayer for fileUrl=" + mediaUrl, e);
return;
}
}
};
new Thread(r).start();
}
/**
* Download the url stream to a temporary location and then call the setDataSource
* for that local file
*/
public void downloadAudioIncrement(String mediaUrl) throws IOException {
URLConnection cn = new URL(mediaUrl).openConnection();
cn.connect();
InputStream stream = cn.getInputStream();
if (stream == null) {
Log.e(getClass().getName(), "Unable to create InputStream for mediaUrl:" + mediaUrl);
}
downloadingMediaFile = new File(context.getCacheDir(),"downloadingMedia_" + (counter++) + ".dat");
FileOutputStream out = new FileOutputStream(downloadingMediaFile);
byte buf[] = new byte[16384];
int totalBytesRead = 0, incrementalBytesRead = 0;
do {
int numread = stream.read(buf);
if (numread <= 0)
break;
out.write(buf, 0, numread);
totalBytesRead += numread;
incrementalBytesRead += numread;
totalKbRead = totalBytesRead/1000;
testMediaBuffer();
fireDataLoadUpdate();
} while (validateNotInterrupted());
stream.close();
if (validateNotInterrupted()) {
fireDataFullyLoaded();
}
}
private boolean validateNotInterrupted() {
if (isInterrupted) {
if (mediaPlayer != null) {
mediaPlayer.pause();
//mediaPlayer.release();
}
return false;
} else {
return true;
}
}
/**
* Test whether we need to transfer buffered data to the MediaPlayer.
* Interacting with MediaPlayer on non-main UI thread can causes crashes to so perform this using a Handler.
*/
private void testMediaBuffer() {
Runnable updater = new Runnable() {
public void run() {
if (mediaPlayer == null) {
// Only create the MediaPlayer once we have the minimum buffered data
if ( totalKbRead >= INTIAL_KB_BUFFER) {
try {
startMediaPlayer();
} catch (Exception e) {
Log.e(getClass().getName(), "Error copying buffered conent.", e);
}
}
} else if ( mediaPlayer.getDuration() - mediaPlayer.getCurrentPosition() <= 1000 ){
// NOTE: The media player has stopped at the end so transfer any existing buffered data
// We test for < 1second of data because the media player can stop when there is still
// a few milliseconds of data left to play
transferBufferToMediaPlayer();
}
}
};
handler.post(updater);
}
private void startMediaPlayer() {
try {
File bufferedFile = new File(context.getCacheDir(),"playingMedia" + (counter++) + ".dat");
moveFile(downloadingMediaFile,bufferedFile);
Log.e("Player",bufferedFile.length()+"");
Log.e("Player",bufferedFile.getAbsolutePath());
mediaPlayer = new MediaPlayer();
mediaPlayer.setDataSource(bufferedFile.getAbsolutePath());
mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
mediaPlayer.prepare();
fireDataPreloadComplete();
} catch (IOException e) {
Log.e(getClass().getName(), "Error initializing the MediaPlaer.", e);
return;
}
}
/**
* Transfer buffered data to the MediaPlayer.
* Interacting with MediaPlayer on non-main UI thread can causes crashes to so perform this using a Handler.
*/
private void transferBufferToMediaPlayer() {
try {
// First determine if we need to restart the player after transferring data...e.g. perhaps the user pressed pause
boolean wasPlaying = mediaPlayer.isPlaying();
int curPosition = mediaPlayer.getCurrentPosition();
mediaPlayer.pause();
File bufferedFile = new File(context.getCacheDir(),"playingMedia" + (counter++) + ".dat");
//FileUtils.copyFile(downloadingMediaFile,bufferedFile);
mediaPlayer = new MediaPlayer();
mediaPlayer.setDataSource(bufferedFile.getAbsolutePath());
//mediaPlayer.setAudioStreamType(AudioSystem.STREAM_MUSIC);
mediaPlayer.prepare();
mediaPlayer.seekTo(curPosition);
// Restart if at end of prior beuffered content or mediaPlayer was previously playing.
// NOTE: We test for < 1second of data because the media player can stop when there is still
// a few milliseconds of data left to play
boolean atEndOfFile = mediaPlayer.getDuration() - mediaPlayer.getCurrentPosition() <= 1000;
if (wasPlaying || atEndOfFile){
mediaPlayer.start();
}
}catch (Exception e) {
Log.e(getClass().getName(), "Error updating to newly loaded content.", e);
}
}
private void fireDataLoadUpdate() {
Runnable updater = new Runnable() {
public void run() {
textStreamed.setText((CharSequence) (totalKbRead + " Kb read"));
float loadProgress = ((float)totalKbRead/(float)mediaLengthInKb);
progressBar.setSecondaryProgress((int)(loadProgress*100));
}
};
handler.post(updater);
}
/**
* We have preloaded enough content and started the MediaPlayer so update the buttons & progress meters.
*/
private void fireDataPreloadComplete() {
Runnable updater = new Runnable() {
public void run() {
mediaPlayer.start();
startPlayProgressUpdater();
playButton.setEnabled(true);
//streamButton.setEnabled(false);
}
};
handler.post(updater);
}
private void fireDataFullyLoaded() {
Runnable updater = new Runnable() {
public void run() {
transferBufferToMediaPlayer();
textStreamed.setText((CharSequence) ("Audio full loaded: " + totalKbRead + " Kb read"));
}
};
handler.post(updater);
}
public MediaPlayer getMediaPlayer() {
return mediaPlayer;
}
public void startPlayProgressUpdater() {
float progress = (((float)mediaPlayer.getCurrentPosition()/1000)/(float)mediaLengthInSeconds);
progressBar.setProgress((int)(progress*100));
if (mediaPlayer.isPlaying()) {
Runnable notification = new Runnable() {
public void run() {
startPlayProgressUpdater();
}
};
handler.postDelayed(notification,1000);
}
}
public void interrupt() {
playButton.setEnabled(false);
isInterrupted = true;
validateNotInterrupted();
}
public void moveFile(File oldLocation, File newLocation)
throws IOException {
if ( oldLocation.exists( )) {
BufferedInputStream reader = new BufferedInputStream( new FileInputStream(oldLocation) );
BufferedOutputStream writer = new BufferedOutputStream( new FileOutputStream(newLocation, false));
try {
byte[] buff = new byte[8192];
int numChars;
while ( (numChars = reader.read( buff, 0, buff.length ) ) != -1) {
writer.write( buff, 0, numChars );
}
} catch( IOException ex ) {
throw new IOException("IOException when transferring " + oldLocation.getPath() + " to " + newLocation.getPath());
} finally {
try {
if ( reader != null ){
writer.close();
reader.close();
}
} catch( IOException ex ){
Log.e(getClass().getName(),"Error closing files when transferring " + oldLocation.getPath() + " to " + newLocation.getPath() );
}
}
} else {
throw new IOException("Old location does not exist when transferring " + oldLocation.getPath() + " to " + newLocation.getPath() );
}
}
}
然后您可以轻松地像这样使用它:private void startStreamingAudio() {
try {
final ProgressBar progressBar = (ProgressBar) findViewById(R.id.progress_bar);
if ( audioStreamer != null) {
audioStreamer.interrupt();
}
audioStreamer = new StreamingMediaPlayer(this,textStreamed, playButton, streamButton,progressBar);
audioStreamer.startStreaming("http://www.pocketjourney.com/downloads/pj/tutorials/audio.mp3",1677, 214);
//streamButton.setEnabled(false);
} catch (IOException e) {
Log.e(getClass().getName(), "Error starting to stream audio.", e);
}
https://dev59.com/V1XTa4cB1Zd3GeqP1m9Y#5384161
尝试进行逐字节操作。这个方法是由这个人开发的。如果您正在处理音频数据,则应使用AudioRecord
类而不是MediaRecorder
类。
有一个在线示例代码可供您下载和测试您的应用程序。
如上所述,
本文的示例应用程序记录音频并将其保存到SDCard中。该文件将是WAV文件,并将放置在“/SDCard/AudioRecorder”文件夹中,以当前毫秒数作为文件名。
请查看文章android-audio-recording-part-2/。
附注:
如果您想将记录的文件保存为mp3格式,则修改源代码文件RecorderActivity.java
。在那里,您将看到以下行:private static final String AUDIO_RECORDER_FILE_EXT_WAV = ".wav";
。
将其更改为private static final String AUDIO_RECORDER_FILE_EXT_WAV = ".mp3";
或者
您可以根据您的应用程序需要修改变量名或相关代码。
祝您好运!