I have written a few hundred line app in Clojure that uses the JLayer Java library for audio where I run mp3s in the background. This works fine but as soon as I run any other music, YouTube etc in the background (I'm running Arch Linux) the sounds in my app completely stop.
I have wasted the last two hours and tried dozens of things to fix this so any advice is appreciated.
Since you have stated that you're on Linux, the problem could be on your ALSA driver.
Check whether this article will help you fix the problem.
Though I have no personal coding experience with sound in Java, it is my understanding that there are some mismatched assumptions and/or incomplete APIs when it comes to Linux sound services and also with Java sound interfaces. Mix the two together and you get what you've run into. While playing with FreeTTS, I rand into similar, possibly same problem:
FreeTTS, Java, Linux: Workaround for "LINE UNAVAILABLE: Format is ..."
I've had problems with PulseAudio and Jack fighting for control of sound card before.
Have you considered that? Can you check whether the two apps are fighting each other in that way?
Related
Whats up! I just want to ask, but how do I run an .apk file j2me. I know that this question HAS been asked, but I can't seem to find an answer. Also, i'm not asking to run j2me apps on android; there are already tons of emulators. Im asking for apks running on j2me. I also know that they are developed in different VMs. So, is there any way to do that? Also, another side note, how do i resize the screen of an apk file? Thanks!
-Apersonwithalaptop22
(Edited to be easier to be understood)
You don't. A J2ME environment wouldn't have the Android framework. You'd need to write a complete android framework in the j2me language. It's not as simple as just converting dalvik bytecode to jvm bytecode- it's actually providing every single android class in the SDK. It could be done, but it would take one person a few years to do, and some things would never work quite right. Possibly you can find a project that's tried to start that effort, although I would doubt it- android moves relatively rapidly for them to keep up, and j2me is basically dead.
As for resizing the screen of an APK file- you don't. APK files don't have a screen size. Instead the idea is to write a UI that scales.
I recently started to build an Android App that will make heavy use of MIDI sounds. Problem: The standard Android MIDI sound is just horrible. On Windows and Linux, I vastly improved the sound by applying a soundfont (.sf2) - that doesn't seem to be possible on Android without further ado.
While looking for a solution, EAS_LoadDLSCollection() popped up a few times, but as I'm pretty new to Android programming, I can't figure out how to make use of it.
It's not mandatory that the MIDI sound is changed system wide - just for the app would be enough.
Any hints appreciated.
It looks possible using FluidSynth. You'll have to compile it for the JNI, though. Steps to do so can be found on this thread about it. There are some other interesting comments in that thread, also.
What actually exist to solve Java Video ? It does not work in my linux box, JMF cant detect even my webcam. ex: http://i.stack.imgur.com/Vic0o.png
JMF - works in Mac, i guess no ? Cause in CentOS/Fedora it does not detects my Video camera.
FMJ - ? Does those requires native separate installation ?
LTI-civil ? Does those requires native separate installation ?
Xuggler ? Does those requires native separate installation ?
My most important feature is: Can i use other java video libraries to make eye contacts video frame, means 1 screen from (Sender, Receiver, Third party) 3 to 4 participant in 1 video screen.
Follow up:
Java video does not work: http://i.stack.imgur.com/d6f5V.png
I am now wondering so many years Java remains but Video they didnt completed yet.
Where Adobe Flex/Air is just a few lines of code and its done (still experts dont belive in Flex/Air, i must research why, maybe quality issue and restricted raw access).
Cant figure it out in my small brain about Java and its Video solution.
Many more reason ... researching...
Will, Appreciate more advise!
JMF is sadly neglected from Sun, and FMJ was started to rectify this. I would start with FMJ and see how it works for you.
dsj - DirectShow is also a good choice and dont need a separate installation.
http://www.humatic.de/htools/dsj.htm
I have a general old-fashioned phone that has no special app system and uses Java (I assume ME) for the few applications you can use on it.
This is still a decent userbase and I'd like to start programming for this type of phone. I already know basic Java theory and syntax, so.. where do I get started for programming for non-smartphones?
Best programming environment for Java ME IMO is Eclipse with EclipseME. Includes lots of built-in stuff about packaging your midlets etc. The SonyEricsson wireless toolkit is great for PC-based testing and debugging, but don't forget on-device testing!
If you don't know much about Java ME's lifecycle, then get reading as widely as you can, and try lots and lots of examples. Start with the JSR-118 (MIDP2) javadocs; you'll want these open on your desktop at all times while coding.
Don't waste too much time with the form-based user-interface; I recommend either rolling your own using Canvas, or read about LWUIT.
You can do all sorts in Java ME and target a very broad range of handsets. HTTP capability is guaranteed, so you can hook up to a public web service, or create your own using something like Google Appengine.
Finally, you can release your app very easily on somewhere like Get Jar. Don't be put off by those who say "no owners of Java ME handsets want apps", you'll find the most popular user bases on this site will be users in countries such as India and Indonesia.
Good luck!
I would start with a book on J2ME and work from there.
Try Beginning J2ME: From Novice to Professional.
You could also download the J2ME SDK and play around with the example they give.
For tutorials have a look at the stackoverflow question https://stackoverflow.com/questions/584923/do-you-know-a-good-j2me-tutorial as mention in my comment.
I started with writing simple Flashlight application (choose how much seconds screen will remain lit) in NetBeans ME. And other app which I mange was Countdown with some graphics and sound. After that I found limitations too much annoying and now I'm waiting for my Android phone.
in short:
If you want to try it out - you don't need to buy books. There are plenty of tutorials around.
But, if you want to start deep development - don't waste time.
I need simple video playback in Java.
Here are my requirements:
PRODUCTION QUALITY
Open and decode video files whose video and audio codecs can be chosen by me. I.E I can pick well behaving codecs.
Be able to play, pause, seekToFrame OR seekToTime and stop playback. Essentially I wish to be able to play segments of a single video file in a non linear fashion. For example I may want to play the segment 20.3sec to 25.6sec, pause for 10 seconds and then play the segment 340.3sec to 350.5sec, etc.
During playback, video and audio must be in sync.
The video must be displayed in a Swing JComponent.
Must be able to use in a commercial product without having to be open source (I.E. LGPL or Comercial is good)
My research has led me to the following solutions:
Use Java Media Framework + Fobs4JMF
http://fobs.sourceforge.net/f4jmf_first.html
I have implemented a quick prototype and this seems to do what I need. I can play a segment of video using:
player.setStopTime(new Time(end));
player.setMediaTime(new Time(start));
player.start();
While Fobs4JMF seems to work, I feel the quality of the code is poor and the project is no longer active. Does anyone know of any products which use Fobs4JMF?
Write a Flash application which plays a video and use JFlashPlayer to bring it into my Java Swing application
Unlike Java, Flash is brilliant at playing video. I could write a small Flash application with the methods:
open(String videoFile),
play(),
pause(),
seek(int duration),
stop()
Then bring it into Java using JFlashPlayer which can call Flash functions from Java.
What I like about this solution is that video playback in Flash should be rock solid. Has anyone used JFlashPlayer to play video in Java?
Write a simple media player on top of Xuggler
Xuggler is an FFMpeg wrapper for Java which seems to be a quite active and high quality project. However, implementing the simple video playback described in the requirements is not trivial (Seeking in particular) but some of the work has been done in the MediaTools MediaViewer which would be the base upon which to build from.
Use FMJ
I have tried to get FMJ to work but have had no sucess so far.
I would appreciate your opinions on my problem.
Can a brother get a shout out for Xuggler?
In my mind, VLCJ is the way forward for this type of thing. I love Xuggler for encoding / transcoding work, but unfortunately it's just so complicated to do simple playback and solve all the sync issues and suchlike - and it does very much feel like reinventing the wheel doing so.
The only thing with VLCJ is that to get it to work reliably with multiple players I've had to resort to out of process players. The framework wasn't the simplest thing in the world to get in place, but when it's there it works beautifully. I'm currently running 3 out of process players in my app side by side with no problems whatsoever.
The other caveat is that the embedded media player won't work with a swing component, just a heavyweight canvas - but that hasn't proven a problem for me at all. If it does, then you can use the direct media player to get a bufferedimage and display that on whatever you choose, but it will eat into your CPU a bit more (though no more than other players that take this approach.)
JavaFX has a number of working video and audio codecs builtin. It's likely to be the solution with the broadest support at the moment.
I've been using jffmpeg in the same way you use FOBS, it works pretty well, although I haven't compared them.
I would also love to see an easy way to interface with native codecs the way that JavaFX does, but there doesn't seem to be real integration between JavaFX and Java.
There has also been some work trying to get the VLC library libvlc into java. I haven't tried it yet and would be interested to hear back from anyone who has.
haven't tried Xuggler (which i'm interested in) but I'm having a good time with VLCJ. The drawback I find in it is only that you have to have VLC installed prior to your application.
I'd recommend using MPV. You can use it in combination with JavaFX quite easily, see this example.
In short, you use a little JNA magic to use the MPV native libaries directly, and then let the video display on a JavaFX stage. If you use a child stage, you can even overlay JavaFX controls on top of the video (with full transparancy support).
VLC (with VLCJ) can be used in a similar fashion, but I find that the MPV solution performs better (faster seek and start times).