Develop Reference

Writing an audio file to websocket using IBM Watson Android sdk

I realized after going through a post in the IBM developer forums that the android sdk reads bytes from the mic recording and writes them to the websocket. I am now trying to read bytes from an audio file on memory and write them to the websocket. How should I do this? So far I have:
public class AudioCaptureThread extends Thread{
private static final String TAG = "AudioCaptureThread";
private boolean mStop = false;
private boolean mStopped = false;
private int mSamplingRate = -1;
private IAudioConsumer mIAudioConsumer = null;
// the thread receives high priority because it needs to do real time audio capture
// THREAD_PRIORITY_URGENT_AUDIO = "Standard priority of the most important audio threads"
public AudioCaptureThread(int iSamplingRate, IAudioConsumer IAudioConsumer) {
android.os.Process.setThreadPriority(android.os.Process.THREAD_PRIORITY_URGENT_AUDIO);
mSamplingRate = iSamplingRate;
mIAudioConsumer = IAudioConsumer;
}
// once the thread is started it runs nonstop until it is stopped from the outside
#Override
public void run() {
File path = Activity.getContext.getExternalFilesDir(null);
File file = new File (path, "whatstheweatherlike.wav");
int length = (int) file.length();
ByteArrayOutputStream bos = new ByteArrayOutputStream();
byte[] b = new byte[length];
FileInputStream in = null;
try {
in = new FileInputStream(file);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
try {
for (int readNum; (readNum = in.read(b)) != -1;) {
bos.write(b, 0, readNum);
}
} catch (IOException e) {
e.printStackTrace();
}
byte[] bytes = bos.toByteArray();
mIAudioConsumer.consume(bytes);
}
However, Activity.getContext is not recognized. I can convert the file to bytes in MainActivity but how do I then write it to the websocket? Am I on the right track or is this not the right way? If it is, how do I solve this problem?
Any help is appreciated!

Activity.getContext is not recognized because there's no reference to Activity, since it's just a Thread. You would have to pass in the Activity, although it would likely make more sense just to pass in the Context if you need it.
You've got the right idea that you can create a FileInputStream and use that. You might like to use our MicrophoneCaptureThread as a reference. It'd be a very similar situation, except you'd be using your FileInputStream instead of reading from the microphone. You can check it out (and an example project that uses it) here: https://github.com/watson-developer-cloud/android-sdk/blob/master/library/src/main/java/com/ibm/watson/developer_cloud/android/library/audio/MicrophoneCaptureThread.java

0-byte files not detected when downloading files on Android

I have an app for Android which downloads hundreds of files from the Internet. Some files turn out to be 0-byte after download. The app attempts to detect such cases and delete such files after download but sometimes it fails. The problem is more frequent on Android 4.x devices.
Here is the method which does the downloading. I gets the number of actually read bytes from inputStream.read(buffer).
public class Utils
{
public static class DownloadFileData
{
int nTotalSize;
int nDownloadedSize;
}
public interface ProgressCallback
{
void onProgress(long nCurrent, long nMax);
}
public static boolean downloadFile(String sFileURL, File whereToSave, DownloadFileData fileData, ProgressCallback progressCallback)
{
InputStream inputStream = null;
FileOutputStream fileOutput = null;
try
{
URL url = new URL(sFileURL);
URLConnection connection = url.openConnection();
//set up some things on the connection
connection.setDoOutput(true);
connection.connect();
fileOutput = new FileOutputStream(whereToSave);
inputStream = connection.getInputStream();
fileData.nTotalSize = connection.getContentLength();
fileData.nDownloadedSize = 0;
byte[] buffer = new byte[1024];
int bufferLength = 0; //used to store a temporary size of the buffer
// now, read through the input buffer and write the contents to the file
while ((bufferLength = inputStream.read(buffer)) > 0)
{
// if interrupted, don't download the file further and return
// also restore the interrupted flag so that the caller stopped also
if (Thread.interrupted())
{
Thread.currentThread().interrupt();
return false;
}
// add the data in the buffer to the file in the file output stream
fileOutput.write(buffer, 0, bufferLength);
// add up the size so we know how much is downloaded
fileData.nDownloadedSize += bufferLength;
if (null != progressCallback && fileData.nTotalSize > 0)
{
progressCallback.onProgress(fileData.nDownloadedSize, fileData.nTotalSize);
}
}
return true;
}
catch (FileNotFoundException e)
{
return false; // swallow a 404
}
catch (IOException e)
{
return false; // swallow a 404
}
catch (Throwable e)
{
return false;
}
finally
{
// in any case close input and output streams
if (null != inputStream)
{
try
{
inputStream.close();
inputStream = null;
}
catch (Exception e)
{
}
}
if (null != fileOutput)
{
try
{
fileOutput.close();
fileOutput = null;
}
catch (Exception e)
{
}
}
}
}
Here is the piece of code which processes the downloads. Since sometimes the number of read bytes is incorrect (it is > 0 and the real file has the size 0 bytes) I check the size of the downloaded file with outputFile.length(). But this again gives a value > 0 even though the file is really 0 byte. I tried to also just create a new file and read its size with recheckSizeFile.length(). Still the size is determined as > 0 while it's really 0 byte.
Utils.DownloadFileData fileData = new Utils.DownloadFileData();
boolean bDownloadedSuccessully = Utils.downloadFile(app.sCurrenltyDownloadedFile, outputFile, fileData, new Utils.ProgressCallback()
{
... // progress bar is updated here
});
if (bDownloadedSuccessully)
{
boolean bIsGarbage = false;
File recheckSizeFile = new File(sFullPath);
long nDownloadedFileSize = Math.min(recheckSizeFile.length(), Math.min(outputFile.length(), fileData.nDownloadedSize));
// if the file is 0bytes, it's garbage
if (0 == nDownloadedFileSize)
{
bIsGarbage = true;
}
// if this is a video and if of suspiciously small size, it's
// garbage, too
else if (Utils.isStringEndingWith(app.sCurrenltyDownloadedFile, App.VIDEO_FILE_EXTENSIONS) && nDownloadedFileSize < Constants.MIN_NON_GARBAGE_VIDEO_FILE_SIZE)
{
bIsGarbage = true;
}
if (bIsGarbage)
{
++app.nFilesGarbage;
app.updateLastMessageInDownloadLog("File is fake, deleting: " + app.sCurrenltyDownloadedFile);
// delete the garbage file
if (null != outputFile)
{
if (!outputFile.delete())
{
Log.e("MyService", "Failed to delete garbage file " + app.sCurrenltyDownloadedFile);
}
}
}
else
{
... // process the normally downloaded file
}
I am not sure but I think there is a bug in Android with reading file size. Has anyone seen a similar problem? Or am I maybe doing something wrong here?
Thanks!
EDIT: how i determine that the files are 0-byte:
all the files which get downloaded go thru the described routines. When I then later view the download folder with a file browser (Ghost Commander), some of the files (like maybe 10%) are 0-byte. They can't be played by a video player (shown as "broken file" icon).

It looks to me like your problem is that you only check for "garbage" files if the Utils.downloadFile call returns true. If the download fails in the getInputStream call or the first read, you will have created a file with zero length which will never be deleted.

You should call flush() on your FileOutputStream to ensure that all data is written to the file. This should make your issue with 0-byte files occur less often.
To check for 0 byte files using File.length() should work properly. Can you open a shell (adb shell) on the device and run ls -l to see the byte count displayed by it is 0 (maybe your file manager has some weird issues). Also please debug (or put some log statements) that sFullPath contains the correct file paths. I can't see where sFullPath gets set in your code above and why you don't just use outputFile but recreate another File object.

Trying to read a text file in res/raw with scanner

Hello,
I am trying to read a file with a Scanner so I can use the input of the strings to construct other objects. However my scanner is always throwing a NullPointerException when trying to create it. I have a pig.txt text file in the res/raw folder but my scanner can not seem to access it. I do not know what I am doing wrong. I have comment out other code of the method but still get an exception.
public void loadAchievements() {
try {
Scanner s = new Scanner(getResources().openRawResource(R.raw.pig));
/**
* s = s.useDelimiter("."); Scanner StringScanner; StringScanner =
* new Scanner(s.next()); StringScanner =
* StringScanner.useDelimiter(":"); String keep =
* StringScanner.next(); String StringKeeper = StringScanner.next();
* this.achievementBoard.add(new Achievement_Item(keep,
* StringKeeper)); StringScanner.close(); s.close();
**/
} catch (NullPointerException e) {
e.printStackTrace();
System.out.println("NULLPOINTER");
}
}

I had this problem today, and I resolved somehow.
I know that old question, but I would share it if others have stuck.
public class Question {
private int numberOfQuestion;
private String[] myquestion;
public Question(InputStream file_name) {
Scanner scanner = null;
try {
scanner = new Scanner(file_name);
} catch (Exception e) {
Log.d("Question", "Scanner :" + e);
System.exit(1);
}
this.numberOfQuestion = scanner.nextInt();
scanner.nextLine();
myquestion = new String[numberOfQuestion];
for (int i = 0; i < numberOfQuestion; ++i) {
myquestion[i] = scanner.nextLine();
}
scanner.close();
}
---------------------------------------------------------
call:
try {
MyScanner myScanner = new MyScanner(getResources().openRawResource( R.raw.input_question));
} catch (Exception e) {
Log.d("Error", "input_question.txt");
}

openRawResource() method can only be used to open drawable, sound, and raw resources; it will fail on string and color resources. Since your pig.txt is a text file that contains a String, openRawResource() won't be able to open a new stream therefore your stream is null.

Using an arbitrary stream as a source for MediaPlayer

I would like to use an arbitrary InputStream as a data source for a MediaPlayer object.
The reason for this is that the InputStream I am using is in fact an authorized HTTPS connection to a media resource on a remote server. Passing the URL in that case will obviously not work as an authentication is required. I can however do the authentication separately and get an InputStream to the resource - problem is what do I do once I have it?
I thought about the option of using a named pipe and passing its FileDescriptor to the setDataResource method of MediaPlayer. Is there a way to create named pipes in Android (without using NDK)?
Any other suggestion is most welcome.

I think I have found a solution. I would appreciate it if others who are interested would try this on their own and report the results with their device models and SDK version.
I have seen similar posts which direct to this but I thought I would post it anyway since it is newer and seems to work on newer versions of the SDK - so far it works on my Nexus One running Android 2.3.6.
The solution relies on bufferring the input stream to a local file (I have this file on the external storage but it will probably be possible to place it on the intenal storage as well) and providing that file's descriptor to the MediaPlayer instance.
The following runs in a doInBackground method of some AsyncTask that does AudioPlayback:
#Override
protected
Void doInBackground(LibraryItem... params)
{
...
MediaPlayer player = new MediaPlayer();
setListeners(player);
try {
_remoteStream = getMyInputStreamSomehow();
File tempFile = File.createTempFile(...);
tempFile.deleteOnExit();
_localInStream = new FileInputStream(tempFile);
_localOutStream = new FileOutputStream(tempFile);
int buffered = bufferMedia(
_remoteStream, _localOutStream, BUFFER_TARGET_SIZE // = 128KB for instance
);
player.setAudioStreamType(AudioManager.STREAM_MUSIC);
player.setDataSource(_localInStream.getFD());
player.prepareAsync();
int streamed = 0;
while (buffered >= 0) {
buffered = bufferMedia(
_remoteStream, _localOutStream, BUFFER_TARGET_SIZE
);
}
}
catch (Exception exception) {
// Handle errors as you see fit
}
return null;
}
The bufferMedia method buffers nBytes bytes or until the end of input is reached:
private
int bufferMedia(InputStream inStream, OutputStream outStream, int nBytes)
throws IOException
{
final int BUFFER_SIZE = 8 * (1 << 10);
byte[] buffer = new byte[BUFFER_SIZE]; // TODO: Do static allocation instead
int buffered = 0, read = -1;
while (buffered < nBytes) {
read = inStream.read(buffer);
if (read == -1) {
break;
}
outStream.write(buffer, 0, read);
outStream.flush();
buffered += read;
}
if (read == -1 && buffered == 0) {
return -1;
}
return buffered;
}
The setListeners method sets handlers for various MediaPlayer events. The most important one is the OnCompletionListener which
is invoked when playback is complete. In cases of buffer underrun (due to, say, temporary slow network connection) the player
will reach the end of the local file and transit to the PlaybackCompleted state. I identify those situations by comparing the
position of _localInStream against the size of the input stream. If the position is smaller, then playback is now really completed
and I reset the MediaPlayer:
private
void setListeners(MediaPlayer player)
{
// Set some other listeners as well
player.setOnSeekCompleteListener(
new MediaPlayer.OnSeekCompleteListener()
{
#Override
public
void onSeekComplete(MediaPlayer mp)
{
mp.start();
}
}
);
player.setOnCompletionListener(
new MediaPlayer.OnCompletionListener()
{
#Override
public
void onCompletion(MediaPlayer mp)
{
try {
long bytePosition = _localInStream.getChannel().position();
int timePosition = mp.getCurrentPosition();
int duration = mp.getDuration();
if (bytePosition < _track.size) {
mp.reset();
mp.setDataSource(_localInStream.getFD());
mp.prepare();
mp.seekTo(timePosition);
} else {
mp.release();
}
} catch (IOException exception) {
// Handle errors as you see fit
}
}
}
);
}

Another solution would be to start a proxy HTTP server on localhost. The media player will connect to this server with setDataSource(Context context, Uri uri). This solution works better than the previous and does not cause playback to glitch.

Simultaneous downloads result in corrupted files

I'm downloading sets of images in separated threads and saving them to the SD card. The problem is that when I run two or more downloading threads the saved images are corrupted. If just one thread is running the images are ok. I'm downloading it from the same domain but different url, e.g. www.test.com/set1/img1.jpg, www.test.com/set2/img1.jpg etc.
I'm saving them to different folders by the name of the set. I noticed that mostly larger images are corrupted (over 500 KB), smaller are usually ok, but not always.
Do you have any clue why the files get corrupted when multiple threads are running?
Here's a part of the code I'm using:
protected class DownloadTask extends DownloadRunnable {
#Override
public void run() {
InputStream is = null;
OutputStream os = null;
File bitmapFile = null;
/** some more declarations and preparations are here */
for (int pg=getDownloadedPages(); pg < numPages; ++pg) {
for (char ch='a'; ch <= 'e'; ++ch) {
/* check for pause */
synchronized (pauseLock) {
while (paused && !aborted) {
try {
pauseLock.wait();
} catch (InterruptedException e) {
}
}
}
fileName = "page-" + df.format(pg) + "-" + ch;
url = MainApp.getRestrictedUrl(MainApp.tstcode, urlFile + fileName+ ".jpg");
is = new BufferedInputStream(new URL(url).openStream());
if(android.os.Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED)) {
bitmapFile = new File(pathToSave, fileName + MagazinePage.FILE_EXT);
MainApp.encryptToFile(bitmapFile, is);
dwnlSize += bitmapFile.length();
}
is.close();
}
}
}
public static void encryptToFile(File file, InputStream is) throws IOException {
BufferedOutputStream os = null;
try {
if (file.exists()) {
file.delete();
} else {
file.getParentFile().mkdirs();
}
file.createNewFile();
os = new BufferedOutputStream(new FileOutputStream(file));
IkioskContentProvider.getInstance().encrypt(is, os);
} finally {
os.close();
}
}
}
DownloadRunnable is custom abstract class implementing Runnable. And I'm using it in thread the regular way:
protected void downloadIssuePages() {
dwnlTask = new DownloadTask();
new Thread(dwnlTask).start();
}
I'm calling downloadIssuePages() on two different objects to download two sets for example.
Using SDK version 11 (Android 3.0), device Acer Iconia Tab A500 with Android 3.1

I've tried to disable writing for the second thread, only the first thread was saving files to find out if there's a problem in reading from the stream or writing. Apparently writing was the problem as data was correct in this case.
So I decided to use lock around writing to the file and looks like it's working fine:
synchronized (MainApp.fileWritingLockObj) {
while (MainApp.fileWritingLocked) {
try {
MainApp.fileWritingLockObj.wait();
} catch (InterruptedException e) {
}
}
MainApp.fileWritingLocked = true;
if(android.os.Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED)) {
bitmapFile = new File(pathToSave, fileName + MagazinePage.FILE_EXT);
MainApp.encryptToFile(bitmapFile, is);
dwnlSize += bitmapFile.length();
}
is.close();
MainApp.fileWritingLocked = false;
MainApp.fileWritingLockObj.notifyAll();
}