Well i´m trying to create a application which should show some streams (udp/rtsp..) I found out that the vlc-player can handle most of it! So i decided to use the vlclib. On windows there is a vlclib which can be easily used. But how can i use the vlc-android project as a vlclib for my own app?
On the web i found another question:
Using libvlc on android with NDK
The answer links to this side:
https://bitbucket.org/tewilove/nyan.tv-jni/src
But the readme is really strange. It tells me only to compile it using the shell script... But this side referring to the nyan.tv-jni project tells me that i can use it simply as a wrapper in my code? http://blog.moenyan.net/?p=18
So now i´m really confused... Can anyone please help me shed some light on how to create my own app using the lib?
Thanks in advance.
I found a solution for my problem. I decided to build my application into the vlc application. I cloned the git-project from vlc and followed the instruction to build a ARM-CPU version. After the successful compilation I was able to merge my project into the vlc application.
Just change the package in the AndroidManifest.xml, change the declared classes from for example:
.GUI.Main to org.videolan.GUI.Main
Remember to do not register your Main as the starting activity. Just start your activity after finishing the onCreate() of the VLC-Main activity. Remember to call finish() in the onResume() of the VLC-Main activity. The onResume() will be called after your destroyed your own activity.
// OnCreate
VLC.Main.onCreate() -> startActivity(Intent) -> MyApplication.Main.onCreate()
// OnDestroy
MyApplication.Main.onDestroy() -> VLC.Main.onResume() -> VLC.Main.onDestroy()
/!\ Remember to credit the VLC-Team for the great base!
Related
I am working on a Google glass Android app. I have installed the glass development kit (GDK) in Android SDK. Now I created a glass project using Android Studio (Version 3.3.2). The newly created project is showing an error "Default Activity not found" in run->edit configuration.
Please refer the screenshot for the error.
1.
And 2. By clicking run->Edit Configuration in menu.
I have searched a lot on Google and found many articles regarding the same. All are suggested to set the edit configurations option like below.
Module: app
Package: Deploy default APK
Activity: Launch default Activity
Target Device: USB Device
I did the same, but no one is working for me. After spending the whole day to make it work, I came here. This error is due to the Launcher activity, because there is no launcher activity in Google glass project instead it uses Voice Trigger intent filter. It is similar to wearable apps they also don't have the launcher activity.
Android Studio won't let you use a standard run configuration without specifying a launcher in the manifest.
You could try using the gradle command line instead:
./gradlew installDebug
In case you haven't resolved the issue. I came across similar issue before, two ways worked for me:
Choose "Nothing" as the option. You will be able to run the app manually on the Glass, but your debugger won't work straight away. You have to manually attach the debugger to the process. You may also have to use logcat if there is a bug in the launching process.
Specify an activity (whichever is associated with voice trigger).
Also, I noticed that you created the app using Kotlin. Kotlin activity didn't work in my case, throwing exceptions associated with nullable var when resuming the activity. Non-activity classes worked fine. Please let me know if Kotlin activity worked in your case.
I'm new to android development.
I download a toy project and want to figure out the flow of this project.
Can I use debugging to figure out it and how?
Let me explain it more detail. Every android project starts from an "main" activity. I guess I find the "main" activity for the project and set a breakpoint at the onCreate method of this "main" activity. I expect to run this project from that breakpoint one step by step to figure out the flow. However it doesn't work since the debugging stop after finishing the onCreate method.
Start with AndroidManifest.xml file. Open it and look for an Activity with LAUNCHER category. Then open that Activity and go to onCreate(...) method. This is where your app starts. Inside the method, there is a call to setContentView(R.layout.some_layout). some_layout.xml in res/layout folder is UI for this Activity.
Each window you see in Android app is an Activity and each Activity has a layout file.
The "flow" of an android application is more like an asynchronous model than a sequential flow of action. There is a main application loop that processes external events (such as clicks on button) and callbacks related to the activity lifecycle (such as your onCreate method), and lot of other stuff.
Every event is put into the queue and processed asynchronously, so it's not easy to follow it. It's better to think about actions and reactions. In any case you can dig into the android source code and see what's running behind the scenes. Some hints about the model of android apps can be found here but any google search for "android ui thread queue" would lead to relevant info.
If you want to learn the flow of a typical android application, I would recommend you download the samples if you haven't already and add your own log statements. You could use the debugger too. Then start making small changes here and there to force different 'flows' of control, as you make guesses about what should happen and observe your logging statements and the app behavior to see what's going on.
The sample projects can be downloaded from the adt plugin in eclipse and come as ready-made projects. They are also a good way to learn because they are generally the 'best-practice' way of doing things.
Hope that helps! Good luck :)
I'm experimenting with Simple widget application in Xamarin studio and would like to know how to debug it. Trying regular 'Run -> Start Debugging' (F5) produces
Application does not contain a launchable activity
As far as I understand ActivityAttribute.MainLauncher property is designed specifically for this purpose but there is no activity to apply it to in the example I'm playing with.
p.s.
Is there something similar to 'Attach to process' feature?
It seems that there is still no simple solution other than embedding your widget into a self created activity just for the debugging purposes. The last post from the Xamarin team I've found is here.
I've tried a few approaches with an empty activity and trying to trick the debugger - but failed.
I'm trying to call ffmpeg.c to trim a video based on this code 'video-trimmer'. So when I try to run the activity (that loads and uses the native lib) the first time I click trin it works and I could trim the video but when I try to run it again it crashes (and it only work with the application restarts).
So I spend three days looking for a solution for this issue, most of the answers says the issue with the static variables in ffmpeg.c and creating a lib that loads and unload the class fixes the issue (answer1, answer2). So I tried to apply the solution that is based on the answers and this github repo on the video-trimmer project but all my attempts failed.
Is there any one knows about a fork of the 'video-trimmer' project that fixes the issue?. or can anybody provide step by step answer of how to implement the solution in the 'video-trimmer' project (because I tried to follow all the solution on the web and apply them in that project but with no luck).
the problem seems to be with the initialized values (some variables are declared as global static vars, presumably for ease of access but breaks OOP principles and causes us problems like you're facing), however, there are a few ways round this that I can think of:
write a quick function to manually set the static vars back to their correct init values (quick and dirty but works). A list of methods which should not be allowed to fire off as and when they please follows:
avcodec_register_all(), avdevice_register_all(), av_register_all()
avcodec_find_encoder(), avcodec_find_decoder(), av_find_stream_info()
avcodec_open(), avcodec_close()
these could be wrapped in a boolean controlled method for example so that if they have run previously they cannot run again.
another way to control things is to manually force the variable values (by use of a class or struct to control the ffmpeg global vars) that are being re-initialised on subsequent runs, for example on running the method which currently causes the code to fail, the first step could be to manually set the variables back to their default settings so that they run correctly as at the moment I suspect you have data remaining resident between iterations, and thats what is causing problems.
you could utilse mutexes to ensure that the aforementioned methods behave more responsibly when used with threads.
Addendum:
also (at the C level) use libffmpeginvoke in preference to libffmpeg if you are going to invoke main() multiple times
forcibly invoke Garbage Collection (yep this is another 'ugly' fix) on the call to load the ffmpeg lib, which would then clean things up allowing you to call another instance
Let me know if you need something more in-depth: I can try making a test framework to replicate your problems and see where I get, although that needs access to my home PC as when I am at work I have no Android SDK.
Help us help you, please provide your implemented code or a part of it. Also Crash Log will be helpful.
Hint: Initialise ffmpeg object/thread.
Then use a call back interface. Once the VideoTrimmer gets over, give a callback.
In that callback call the destroy/kill of the ffmpeg object/thread.
May be this link can help you.
I have recently used the "android-ffmpeg-java" project from github, this is a working library, I can guarantee. You just have to implement a wrapper (test application) which will do the work.
Check this link for Source : android-ffmpeg-java
Check this link for example : android-ffmpeg-cmdline. See if you can solve on with this.
I am not sure if this will help, but C files typically have a header where you can use
ifndef
Please see the following:
http://www.cprogramming.com/reference/preprocessor/ifndef.html
Use that syntax to sandwhich the declaration in the associated .h file to ensure multiple imports don't cause a crash in the importing code.
Good Luck!
Edit: Ok, looks like that would mean recompiling ffmpeg to the .so file. You should just try to verify that it has a mechanism as described above in the codebase and try to confirm it isn't somehow being loaded twice.
While somewhat crude, a potential workaround could be to utilize/link to ffmpeg from a Service (you had better be doing that anyway) which is declared in the manifest to run in its own process rather than that of client Activities. Then have that process terminate itself - calling native exit() if needed - when the task is completely finished. Android won't particularly like that happening - it's not good practice - but you can probably make it work.
Re-engineering the library to be able to reset itself to a fresh state (or even make it entirely contextual) would be better, but for a huge legacy codebase may prove to be a large project.
I created an Android test project using instrumentation and it works find with eclipse running as Android Junit test. It also generated apk file.
My question is how do I run this test from another android application instead of from eclipse. For example, if the test project is named T and I have another Android application named A. Then I would like to open up T from A.
Thanks in advance..
I think it will be good if you try to call the appropriate intent on a button click or on whatever you want to start the program. For example:
startActivity(new Intent("com.yourprogram.T") I'm not sure but i think it will works.
Why do you need to open Test project from an app on Device. I dont think you can do it because Android does not allow any app to inject action or call functions from other apps.