On 28.08.2008, at 19:59, Hans-Jörg Bibiko wrote:
On 28.08.2008, at 19:41, Simon Urbanek wrote:Now I only try to avoid a GUI. It looks different on each OS, thus I try to write a simple command line toolThe only idea I have for now is to use a scripting language to write a primitive audio player, and the only language which is installed by default on all these platforms is Java. It shouldn't be that problem to write such a JFrame jar.... But, yes, using Java would be one option except that Java is quite a heavy requirement for such task ...
Well, I tried it out and I came up with a Java command line tool as a jar file (size with source code 4171 bytes). I ran it on Win XP, Vista, Linux SuSe 9.0 and 10.2, Mac Tiger ppc, Mac Leopard i386 and it seems to work properly.
The Java tool simply plays back a given linear PCM sound file (supported formats: wav, aifc, aiff, au, snd). This tool can only run once on a machine, meaning if one invokes it and while playing back a sound file one invokes it with an other sound file, the currently running sound file will be stopped before the next one will be started. This is done by using a simple lock-file mechanism.
If playLinearAudioFile.jar detects a running process it will delete one lock file to interrupt the current process. Due to that fact that the Java script sends buffer by buffer to the audio stream (to minimize CPU and RAM resources) it could take some ticks (depending on the buffer size) before the current process will be interrupted.
To stop a running process one invokes playLinearAudioFile.jar without any arguments. If there's no running process it outputs the usage message.
Furthermore there's an option called '--deleteAfterPlay'. This option enables the user to say, please delete the given sound file after play- back (useful for playing back temporarily generated sound files).
Of course, as already mentioned Java takes some ticks to start that jar script but I've also tested it on slow machines and the time was always below 500ms.
I've also tested it with R. It seems to work, even with the system()'s argument wait=FALSE. While listing to the sound one can do other stuff with R.
To invoke it simply write: java -jar playLinearAudio.jar SOUND_FILEThe Java script only makes usage of commands and packages which are available since Java 1.3.
Unfortunately I couldn't test it on Solaris, AIX, IRIX, ... but if Java 1.3 or up is installed it should work.
The source file and the manifest file 'mainClass.txt' are included in the jar archive.
To create a jar archive:jar cmf mainClass.txt playLinearAudioFile.jar *.class *.java mainClass.txt
If there's an interest, please check it on other OS. I'd be appreciated for any critique.
Cheers, Hans
playLinearAudioFile.jar
Description: application/java-archive
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