Develop Reference

Out of memory - Android

I'm using ffmpeg in my Android application and sometimes I'm getting out of memory error, I'm calling the ffmpeg inside a HandlerThread, is it ok to catch out of memory error and exit the thread while the main thread keeps on running?
I read a lot of this being not a good practice, the thing is that I really need that because I have to edit the DB when there is any kind of error
fc = new FfmpegController(context, fileTmp);
try {
fc.processVideo(clip_in, clip_out, false,
new ShellUtils.ShellCallback() {
#Override
public void shellOut(String shellLine) {
}
#Override
public void processComplete(int exitValue) {
//Update the DB
}
});
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
} catch (InterruptedException e) {
} catch (Exception e) {
}catch (OutOfMemoryError e) {
//update the DB
}

No something is going wrong if you are getting OutOfMemory errors. I would look into buffering your audio, as likely you are running the whole clip through ffmpeg at once, which is going to use up alot of memory.
Also, keep in mind that lots of us doing Audio in Android end up using the NDK primarily because of issues like you are experiencing. Audio has to be really high performance, and using the NDK allows you to write more low level memory efficient audio handling.
Android's AudioTrack has a write method that allows you to push an Audio buffer to it. A warning that this is not entry level and requires some knowledge of AudioBuffer's as well as requires you to read buffers in, send them to ffmpeg and then pass to AudioTrack. Not easy to do, and unfortunately more advanced audio on Android is not easy.

How to set a background template to a pdf using iText library in android?

I wanna set a background Template(image) in my pdf that generated by iText Library,something like this:
Click too see the image
I tried to use something like the code below:
PdfReader reader = new PdfReader("./assets/sarbargandroid.pdf");
PdfImportedPage page = writer.getImportedPage(reader, 1);
PdfContentByte cb = writer.getDirectContent();
cb.addTemplate(page, 0.0, 0.0);
but it did not work in android because .addtemplate() methode needs some awt library!
and I tried addimage stuff like this:
private void setBackground(Chapter document) {
ByteArrayOutputStream stream = new ByteArrayOutputStream();
Bitmap bitmap = BitmapFactory.decodeResource(context.getResources(), R.drawable.sarbarg);
bitmap.compress(Bitmap.CompressFormat.JPEG , 100, stream);
Image img;
try {
img = Image.getInstance(stream.toByteArray());
img.setAbsolutePosition(0, 0);
document.add(img);
} catch (BadElementException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (DocumentException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
But it did't work correctly because the image does not fit the page and it create a pdf like this:
Click too see image
How can I do this correctly? anyone help me??

There are several things wrong with your question and that may explain why nobody answers. I'll tell you what's wrong and then maybe you can create a new question.
You say:
it did not work in android because .addtemplate() methode needs some awt library!
If the addTemplate() method needs an AWT library, then you are using iText. When working on Android, you should use iTextG: http://itextpdf.com/product/itextg
You are using PdfReader which makes people assume that you want to add a background image to an existing document. This would imply that you use PdfStamper, yet your code looks like you're using PdfWriter. That's a contradiction.
Your setBackground() method takes a Chapter as parameter to which you add an image. This is counter-intuitive:
- If you'd want to add a background image to an existing document, you'd never use the Chapter object.
- If you'd want to add a background image to every page of a PDF that is created from scratch, you'd use a page event.
Another major problem is that you create the image and add it as-is. You didn't scale it to fit the page.
Also: if you add an image in the background of an existing PDF. Parts of that image may be covered by opaque shapes that are present in the original document.

Android video encoding with fr and resolution manipulation

I want to be able to take a video recorded with an Android device and encode it to a new Resolution and Frame Rate using my app. The purpose is to upload a much smaller version of the original video (in size), since this will be videos 30 min long or more.
So far, I've read of people saying FFmpeg is they way to go. However, the documentation seems to be lacking.
I have also considered using http opencv http://opencv.org/platforms/android.html
Considering I need to manipulate the video resolution and frame rate, which tool do you think can do such things better? Are there any other technologies to consider?
An important question is, since this will be long videos, is it reasonable to do the encoding in an android device (Consider power resources, time, etc.)
Thanks in advance!

I decided to use ffmpeg to tackle this project. After much researching and trials, I was not able to build ffmpeg for library (using Ubuntu 14.04 LTS.)
However, I used this excellent library https://github.com/guardianproject/android-ffmpeg-java
I just created a project and added that library and it works like a charm. No need to build your own files or mess with the Android NDK. Of course you would still need to build the library yourself if you want to customize it. But it has everything I need.
Here is an example of how I used to lower a video resolution and change the frame rate:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// input source
final Clip clip_in = new Clip("/storage/emulated/0/Developer/test.mp4");
Activity activity = (Activity) MainActivity.this;
File fileTmp = activity.getCacheDir();
File fileAppRoot = new File(activity.getApplicationInfo().dataDir);
final Clip clip_out = new Clip("/storage/emulated/0/Developer/result2.mp4");
//put flags in clip
clip_out.videoFps = "30";
clip_out.width = 480;
clip_out.height = 320;
clip_out.videoCodec = "libx264";
clip_out.audioCodec = "copy";
try {
FfmpegController fc = new FfmpegController(fileTmp, fileAppRoot);
fc.processVideo(clip_in, clip_out, false, new ShellUtils.ShellCallback() {
#Override
public void shellOut(String shellLine) {
System.out.println("MIX> " + shellLine);
}
#Override
public void processComplete(int exitValue) {
if (exitValue != 0) {
System.err.println("concat non-zero exit: " + exitValue);
Log.d("ffmpeg","Compilation error. FFmpeg failed");
Toast.makeText(MainActivity.this, "result: ffmpeg failed", Toast.LENGTH_LONG).show();
} else {
if(new File( "/storage/emulated/0/Developer/result2.mp4").exists()) {
Log.d("ffmpeg","Success file:"+ "/storage/emulated/0/Developer/result2.mp4");
}
}
}
});
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
// automated try and catch
setContentView(R.layout.activity_main);
}
}
The function processVideo produces a command similar to ffmpeg -i input -s 480X320 -r 30 -vcodec libx264 -acodec copy output
This a very simple example, but it outputted the same kind of conversion done by ffmpeg desktop. This codes needs lots of work! I hope it helps anyone.

Running ffmpeg commands from android ffmpeg syntax error in logcat

I have successfully compiled ffmpeg for android and have ported it.
I placed
libffmpeg.so in /system/lib directory
ffmpeg executable in /system/bin and /system/xbin directory (i was not sure where to place it). i directly copied ffmpeg executable from source directory (Not sure whether it's a correct way)
Now i am executing commands from android with following code !!
imports *
public class LatestActivity extends Activity {
private Process process;
String command,text;
static {
System.loadLibrary("ffmpeg");
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_latest);
//Execute Command !!
try {
Execute();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void Execute() throws IOException, InterruptedException{
try {
File dir=new File("/system/bin");
String[] cmd= {"ffmpeg","-codecs"};
process=Runtime.getRuntime().exec(cmd,null,dir);
} catch (IOException e) {
// TODO Auto-generated catch block
Log.d("Process IOException starts:",e.getMessage());
e.printStackTrace();
Log.d("System Manual exit !!",e.getMessage());
System.exit(MODE_PRIVATE);
}
BufferedReader stdInput = new BufferedReader(new InputStreamReader(process.getInputStream()),16384);
BufferedReader stdError = new BufferedReader(new InputStreamReader(process.getErrorStream()));
// read the output from the command
Log.d("Application output: ","Output if any !");
while ((text = stdInput.readLine()) != null) {
Log.d("Output: ",text); //$NON-NLS-1$
}
text="";
// read any errors from the attempted command
Log.d("Application output: ","Errors if any !"); //$NON-NLS-1$
while ((text = stdError.readLine()) != null) {
Log.d("Error: ",text); //$NON-NLS-1$
}
stdInput.close();
stdError.close();
process.waitFor();
process.getOutputStream().close();
process.getInputStream().close();
process.getErrorStream().close();
destroyProcess(process);
//process.destroy();
}
private static void destroyProcess(Process process) {
try {
if (process != null) {
// use exitValue() to determine if process is still running.
process.exitValue();
}
} catch (IllegalThreadStateException e) {
// process is still running, kill it.
process.destroy();
}
}
}
And Here is the logcat output:
09-05 15:29:13.287: D/dalvikvm(2670): No JNI_OnLoad found in /system/lib/libffmpeg.so 0x44e7e910, skipping init
09-05 15:29:29.117: I/global(2670): Default buffer size used in BufferedReader constructor. It would be better to be explicit if an 8k-char buffer is required.
09-05 15:29:29.117: D/Application output:(2670): Output if any !
09-05 15:29:29.117: D/Application output:(2670): Errors if any !
09-05 15:29:29.127: D/Error:(2670): /system/bin/ffmpeg: 1: Syntax error: "(" unexpected
m neither getting any errors nor output of command. At the end it shows syntax error. I want to know what kind of syntax error it is. how to tackle it?
m i doing something wrong?

This Error occurs if the ffmpeg file does not compiled for your cpu architechture.
Your commands might be right but you need to find correct ffmpeg file.

FIXED
#Gaganpreet Singh
You are right after so much research on this, I have got to know that CPU Chip-set matters too, FFMPEG commands doesn't support INTEL ATOM processor.
Asus Memo Pad 7 using INTEL ATOM cpu chip-set and when trying running ffmpeg command on it, it crashes and throw error "SYNTAX ERROR"
My commands working perfectly on all the devices except the device using INTEL ATOM chipset.
Please review this and this link if it will be helpful for you.
If anyone finds a solution. Please share with us.
Finally Fixed this issue by creating ffmpeg lib for x64 & armv7 using NDK. And used this Library in my Andriod project. Now I have 2 lib and using this lib for different Android CPU ARCH.
Please check this link too. Very helpful.

Android- Using DexClassLoader to load apk file

I've hit a bit of a wall. Any help would be appreciated. I have an app that I want to use DexClassLoader to load another apk file.
Here is my code:
DexClassLoader dLoader = new DexClassLoader("/sdcard/download/test.apk","/sdcard/download",null,ClassLoader.getSystemClassLoader().getParent());
Class calledClass = dLoader.loadClass("com.test.classname");
Intent it=new Intent(this, calledClass);
it.setClassName("com.test", "com.test.classname");
startActivity(it);
Now I had already installed test.apk so when I ran the above code it
worked fine and launched the application. However I want to be able to
run this without test.apk being installed already (as that would
defeat the entire point of the application) . So I uninstalled it and
when I ran the my app again I get this error:
android.content.ActivityNotFoundException: Unable to find explicit
activity class {com.test/com.test.classname}; have you declared this
activity in your AndroidManifest.xml.
So I'm a bit stumped here. This activity is declared in the Manifest
of the apk I am trying to run. I can't declare it in my applications
Manifest. Any ideas?
Thanks,
Craig

Try using Android's PathClassLoader:
String packagePath = "com.mypackage";
String classPath = "com.mypackage.ExternalClass";
String apkName = null;
try {
apkName = getPackageManager().getApplicationInfo(packagePath,0).sourceDir;
} catch (PackageManager.NameNotFoundException e) {
// catch this
}
// add path to apk that contains classes you wish to load
String extraApkPath = apkName + ":/path/to/extraLib.apk"
PathClassLoader pathClassLoader = new dalvik.system.PathClassLoader(
apkName,
ClassLoader.getSystemClassLoader());
try {
Class<?> handler = Class.forName(classPath, true, pathClassLoader);
} catch (ClassNotFoundException e) {
// catch this
}

Although the question is old, I will answer because I struggled a bit to find a clear answer for your same question for myself. First, I would like to highlight that a clear requirement in your question is to load a class from an .apk that is not already installed on the device. Therefore, calling the package manager using getPackageManager() and providing it with the package path will clearly lead to NameNotFoundException because the .apk that has the package is not installed on the device.
So, the way to go about loading classes from an .apk file that is not installed on the device (i.e. you only have the .apk stored in a directory on your SDCARD) is by using DexClassLoader as follows:
1- Make sure you have the .apk file in a directory on your SDCARD. I've mine Offloadme.apk in the Download folder on my SDCARD.
2- Add read permission in your AndroidManifest.xml to allow your app to read from the manifest.
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
3- Use the following definitions to define the path of the .apk, the class name inside the apk, and method name in that class that you would like to invoke:
final String apkFile =Environment.getExternalStorageDirectory().getAbsolutePath()+"/Download/Offloadme.apk";
String className = "com.khaledalanezi.offloadme.SimpleCalculator";
String methodToInvoke = "add";
4- Use the DexClassLoader to load the .apk and call the add method in the SimpleCalculator class using reflection as follows:
final File optimizedDexOutputPath = getDir("outdex", 0);
DexClassLoader dLoader = new DexClassLoader(apkFile,optimizedDexOutputPath.getAbsolutePath(),
null,ClassLoader.getSystemClassLoader().getParent());
try {
Class<?> loadedClass = dLoader.loadClass(className);
Object obj = (Object)loadedClass.newInstance();
int x =5;
int y=6;
Method m = loadedClass.getMethod(methodToInvoke, int.class, int.class);
int z = (Integer) m.invoke(obj, y, x);
System.out.println("The sum of "+x+" and "+"y="+z);
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InstantiationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (NoSuchMethodException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalArgumentException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InvocationTargetException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Note that in my simple example, I added two numbers using the add method available in the SimpleCalculator class loaded from the Offloadme.apk file stored on my SDCARD and I was able to print the correct answer which is 11.

You can't do that. Even if you're able to access classes from external file, Android still does not know them. And you don't run activities directly, but by requesting Android to run them, so they have to be registered/installed into system.