I'm thinking of creating a nice gui for ffmpeg command line using Sketchware. Is it possible to add a ffmpeg build into a Sketchware project?
I'd say kinda, you will need an arm-compiled ffmpeg (with it's library statically-linked i believe) for that, and if i'm not wrong, you can execute ffmpeg directly using Runtime.getRuntime().exec("path/to/ffmpeg -arguments");
So it goes on like this:
First, you'll need to include the arm-compiled ffmpeg into your app and extract it at launch at getFilesDir() directory,
Second, the ffmpeg needs to be chmod u+x ffmpeg-ed to allow the user to execute the binary.
Third, just use the above code, Runtime.getRuntime().exec("path/to/ffmpeg -arguments")
Though, I've heard some news that Android 11 is going to restrict binary execution like this.
Another note, I haven't really tried this myself, but if i have time, I'll probably update this answer.
I just found out a precompiled ffmpeg binary that is used on termux here. All you need to do is to manually change the library locaiton to the extracted library location.
I did not understand your question well
, But if you want cmd this class does it
public class CommandLine{
private BufferedReader r;
private Process p;
private ProcessBuilder builder;
private String LinesString = null;
public String run(String command)throws Exception{
builder = new ProcessBuilder(command.split(" "));
builder.redirectErrorStream(true);
p = builder.start();
r = new BufferedReader(new InputStreamReader(p.getInputStream()));
String line = null;
Object[] lines = r.lines().toArray();
for (int i = 0; i < lines.length; i++) {
if(LinesString == null){
LinesString = lines[i].toString();
}else{
LinesString = LinesString + " "+lines[i].toString();
}
}
return LinesString;
}
}
Until you run this class :
try{
String out = new CommandLine().run("echo hi");
} catch (Exception e) {
}
Well,
because it's not even for android, it's quite impossible.
If FFmpeg was for Android, in theory it would be possible.
It is impossible to make a command line for FFmpeg in Android on Sketchware (that is, if you do not need to program any emulators;))
Probably the only option would be a Linux terminal emulator, but in Basic Sketchware I doubt it would work. Otherwise, in sketchware you can do practically anything (especially Sketchware PRO) using the ASD block (Add source directly) which allows you to upload your own code.
Summary; it is not possible. (Or very difficult)
Related
I am doing the dagger tutorial for android in java, and they told me to create this class:
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
CommandRouterFactory commandRouterFactory =
DaggerCommandRouterFactory.create();
CommandRouter commandRouter = commandRouterFactory.router();
while (scanner.hasNextLine()) {
commandRouter.route(scanner.nextLine());
}
}
}
I wrote my own code to try to see what the scanner is pulling from, but nothing shows up. I am just wondering, if System.in is some sort of command line input, and if so, how would I see that show up? I tried typing in the terminal built into android, but that doesn't produce any output either.
Finally, where do you even get a class like this to run in android? I'm only used to having code run at least from the starting point of a main activity.
Here's the link to the tutorial - it doesn't help much with setting up
https://dagger.dev/tutorial/02-initial-dagger
Good day. The main amazing thing about the BeanShell is the idea that i can control what i want to be done dynamically from the server and i thought it would be amazing.
Although i never succeded in achieving that and seems no one else tried to start activity from the beanshell either.
Here how it goes. I simply want to pass the code from the server side to the Android,Android is going to evaluate that code within interpreter and run that.
The issue is that i am getting the exception from BeanShell no matter what i try.
The code from server side is the next.
$response['method'] = "import my.some.name.*;"
. "startActivity(new Intent(this,MyProfile.class))";
The code for Android is the next.
try {
String responseBody = response.body().string();
JSONObject jsonObject = new JSONObject(responseBody);
String method = jsonObject.optString("method");
Interpreter interpreter = new Interpreter();
try {
Object res = interpreter.eval(method);
} catch (EvalError evalError) {
evalError.printStackTrace();
}
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
}
}
But i am getting the next exception from the BeanShell
Sourced file: inline evaluation of: ``import my.some.name.*;startActivity(new Intent(this,MyProfile.class));'' : Class: MyProfile not found in namespace : at Line: 1 : in file: inline evaluation of: ``import my.some.name.*;startActivity(new Intent(this,MyProfile.class));'' : MyProfile
Any ideas what is going on?
Just in case if anyone needs the same solution i am posting for everyone to know.
Here how it goes.
Firstly you need to know that whatever you are trying to do on the server side remember that the BeanShell actually does not know anything about the String code you are passing itself,as it is going to interpret it just like a code out of box so with the help of CommonWare hint about full name path i managed to get it working.
So first step to do is to initialize the Interpreter.
Basic initialization goes like this :
String responseBody = response.body().string();
JSONObject jsonObject = new JSONObject(responseBody);
String method = jsonObject.optString("method");
Interpreter interpreter = new Interpreter();
try {
interpreter.set("context",getApplicationContext());
Object res = interpreter.eval(method);
} catch (EvalError evalError) {
evalError.printStackTrace();
}
Take a very attentive notice about the context as it was my main issue going back and forth as at the moment when i succeded to actually force BeanShell recognize my classes,the BeanShell started to throw Method not found exception about the startActivity() so by thinking logically we can assume that we would set the context as activity as the parent one for our remote methods and start evaluating everything from the context. So here how the remote code is looking.
$response['method'] = "import ink.va.activities;"
. "import android.content.Intent;"
. "import android.content.*;"
. "context.startActivity(new android.content.Intent(context, my.package.name.MyProfile.class));";
The most important things to notice here.
• We are importing everything possible for BeanSherll to recognize our classes,even if they are Android-Build,no matter,still we need to import them.
• If you are going to use any class,then as CommonWare noticed out,you MUST specify the full path to that Class E.G my.package.name.MyProfile.class.
• As i was getting Command Not Found i started to think about the context.startActivity() as i have defined the context beforehand in BeanShell as my parent from which i am going to use methods and Woala,everything worked like a charm!
Possible Problems
I don't know a lot about BeanShell, but there's a couple of issues here
You can import a class (in a compiled language) at runtime
You're trying to do the equivalent of Reflection (but aren't doing any)
Security. No user would consent to you having control to open a screen on their app remotely
Presumably BeanShell is supposed to do the reflection under the covers, but in an case you won't be able to do the import.
Possible solutions
The class/activity using the library should import everything (I'm not sure if a compiler will even retain this)
You can use reflection directly, with things like "method from name". The downside is it's very limited what code you can send from the server unless you handle a myriad of cases.
You could only send names/commands; to specific endpoints in your java app (this is what I recommend) and plan the actions you want ahead of time
$response['method'] = "my.some.name.MyProfile";
JSONObject jsonObject = new JSONObject(response.body().string());
String nameParam = jsonObject.optString("method");
Class<? extends Activity> clazz = Class.forName(nameParam); //wrap with try
startActivity( new Intent(this, clazz) )
I have a Java SE Application that use
input = new Scanner(System.in);
to get Input parameters
and use System.out.println("..");
to print results
Since all Java APIs used in the original Java Project are also available in Android, I have tried to import all classes without any error, but now I don't know how replicate the behaviour of the classic Java console in Android.
I have seen that there are developers that have achieved this in some IDE-like apps, but I don't know how.
Could you help me?
Example:
assume that you want to port this dummy Java SE Application in Android mantaining the console-like approach of the original code
public static void main(String[] args) {
System.out.println("Please enter your choice");
System.out.println("A, B");
Scanner myScanner = new Scanner(System.in);
String choice = myScanner .nextLine();
if (choice.charAt(0) == 'A') {
...do something
}
else{
...do something
}
}
You can execute system commands with exec(). Here is how to do it:
Runtime r = Runtime.getRuntime();
Process p = r.exec("uname -a"); // here goes your input
p.waitFor();
BufferedReader b = new BufferedReader(new InputStreamReader(p.getInputStream()));
String line = "";
while ((line = b.readLine()) != null) {
System.out.println(line);
}
Update:
Ok, from what I understand, you would like to compile and run code written by user. I can see 3 options:
Most difficult I think. Get the source code of some Java compiler and include it in your project. So, user inputs a text. You compile it, run and give the output.
Using already built compiler. This requires root. Install javac on your device. Then, in your application you can call it with the above exec() code.
Easiest one. Using internet and for example, Ideone.com. In your app you send code to compile on Ideone. You get back the output and present it to the user.
Is is possible to run getevent from an Android service and get output similar to what you see when running adb to call getevent from a command prompt on a development machine? When I try something like:
ProcessBuilder builder = new ProcessBuilder()
.command("getevent")
.redirectErrorStream(true)
.start();
BufferedReader reader = new BufferedReader(new InputStreamReader(builder.getInputStream()));
...
the output I get for each device looks like:
could not open /dev/input/event[n], Permission denied
Is it just not possible to access low level information like this because of Android's security protections? Would it be possible on a "rooted" device?
Why I am trying to do this:
I would like to record a user's actions (touch and gesture events) on an Android device for the purpose of usability testing. An accessibility service seems to be the way to go, but the information is not detailed enough. For a swipe gesture, for example, I cannot get the screen coordinates of where the user swiped. I was thinking that getting the low-level input from the touch screen might let me get more detailed information. Maybe there is a better way to do this?
(I'm a newbie in the Android world. This kind of thing is easy on Windows.)
You can do like this.
th = new Thread(new Runnable(){
private Process exec;
#Override
public void run() {
try {
exec = Runtime.getRuntime().exec(new String[]{"su","-c","getevent -t " + device});
InputStreamReader is = new InputStreamReader(
exec.getInputStream());
String s;
BufferedReader br = new BufferedReader(is);
while(((s = br.readLine()) != null) && run){
...
}
is.close();
exec.destroy();
} catch (IOException e) {
e.printStackTrace();
}
}
You must use 'su' to get the root permission, but by this way you can't get the real time event, because there is a buffer size of 4k, you could get data only after contained 4k data.
Search for UIAutomator. This does what you want to do.
Your phone must be rooted to execute getevent/sendevent command.
One way is to install any terminal emulator from play store like Qute: Command Console & Terminal Emulator.
In terminal enter following:
1) su (it'll gain the root access required for getevent)
2) getevent (or getevent -c 8 to output only 8 lines else it would flood the terminal)
I doubt if there is a way to make compile-time conditions in Java like #ifdef #ifndef in C++.
My problem is that have an algorithm written in Java, and I have different running time improves to that algorithm. So I want to measure how much time I save when each improve is used.
Right now I have a set of boolean variables that are used to decide during the running time which improve should be used and which not. But even testing those variables influences the total running time.
So I want to find out a way to decide during the compilation time which parts of the program should be compiled and used.
Does someone knows a way to do it in Java. Or maybe someone knows that there is no such way (it also would be useful).
private static final boolean enableFast = false;
// ...
if (enableFast) {
// This is removed at compile time
}
Conditionals like that shown above are evaluated at compile time. If instead you use this
private static final boolean enableFast = "true".equals(System.getProperty("fast"));
Then any conditions dependent on enableFast will be evaluated by the JIT compiler. The overhead for this is negligible.
javac will not output compiled code that is unreachable. Use a final variable set to a constant value for your #define and a normal if statement for the #ifdef.
You can use javap to prove that the unreachable code isn't included in the output class file. For example, consider the following code:
public class Test
{
private static final boolean debug = false;
public static void main(String[] args)
{
if (debug)
{
System.out.println("debug was enabled");
}
else
{
System.out.println("debug was not enabled");
}
}
}
javap -c Test gives the following output, indicating that only one of the two paths was compiled in (and the if statement wasn't):
public static void main(java.lang.String[]);
Code:
0: getstatic #2; //Field java/lang/System.out:Ljava/io/PrintStream;
3: ldc #3; //String debug was not enabled
5: invokevirtual #4; //Method java/io/PrintStream.println:(Ljava/lang/String;)V
8: return
I think that I've found the solution, It's much simpler.
If I define the boolean variables with "final" modifier Java compiler itself solves the problem. Because it knows in advance what would be the result of testing this condition.
For example this code:
boolean flag1 = true;
boolean flag2 = false;
int j=0;
for(int i=0;i<1000000000;i++){
if(flag1)
if(flag2)
j++;
else
j++;
else
if(flag2)
j++;
else
j++;
}
runs about 3 seconds on my computer.
And this one
final boolean flag1 = true;
final boolean flag2 = false;
int j=0;
for(int i=0;i<1000000000;i++){
if(flag1)
if(flag2)
j++;
else
j++;
else
if(flag2)
j++;
else
j++;
}
runs about 1 second. The same time this code takes
int j=0;
for(int i=0;i<1000000000;i++){
j++;
}
Never used it, but this exists
JCPP is a complete, compliant,
standalone, pure Java implementation
of the C preprocessor. It is intended
to be of use to people writing C-style
compilers in Java using tools like
sablecc, antlr, JLex, CUP and so
forth. This project has has been used
to successfully preprocess much of the
source code of the GNU C library. As
of version 1.2.5, it can also
preprocess the Apple Objective C
library.
http://www.anarres.org/projects/jcpp/
If you really need conditional compilation and you use Ant, you might be able to filter your code and do a search-and-replace in it.
For example: http://weblogs.java.net/blog/schaefa/archive/2005/01/how_to_do_condi.html
In the same manner you can, for example, write a filter to replace LOG.debug(...); with /*LOG.debug(...);*/. This would still execute faster than if (LOG.isDebugEnabled()) { ... } stuff, not to mention being more concise at the same time.
If you use Maven, there is a similar feature described here.
If you use IntelliJ there is a plugin called Manifold, that - along with many other features - allows one to use #ifdef and #define in Java.
Plugin url:
https://manifold.systems/
Preprocessor information:
https://github.com/manifold-systems/manifold/tree/master/manifold-deps-parent/manifold-preprocessor
PS: I am not affiliated with them, we just happen to use it, and it helps a lot with out workflow (which is likely NOT typical for Java development)
Use the Factory Pattern to switch between implementations of a class?
The object creation time can't be a concern now could it? When averaged over a long running time period, the biggest component of time spent should be in the main algorithm now wouldn't it?
Strictly speaking, you don't really need a preprocessor to do what you seek to achieve. There are most probably other ways of meeting your requirement than the one I have proposed of course.
final static int appFlags = context.getApplicationInfo().flags;
final static boolean isDebug = (appFlags & ApplicationInfo.FLAG_DEBUGGABLE) != 0