Intel Spatial Audio for Java* Package Technical FAQ

Beta 1.3.0

Installation and Compatibility Problems

Q. When I try to run an applet that uses Intel Spatial Audio for Java*, I get an error message like this: "Applet exception: class <class name> got a security violation: method verification error" or "java.lang.NoClassDefFoundError." What's wrong?
Q. When I try to run one of the sample applets, the Java Console prints a message like "Failed to create the environment" and the applet fails to run. What's wrong?
Q. When I try to run one of the sample applets, the Java Console prints a message like "Failed to create the listener" and I don't hear any audio. What's wrong?
Q. The sample applets seem to be running, but I don't hear anything. What's wrong?
Q. Netscape Navigator* 2.0 supports Java. Why don't the applets run in it?
Q. Where is the Java Console for Microsoft Internet Explorer*?
Q. I am having problems getting applets to run in one or more supported environments. How can I validate my installation?
Q. When the installation finished, I was left with a dialog box labeled "RSX 3D - Realistic Sound Experience Configuration Utility." What is it and what is it for?
Q. My browser crashed. When I brought it back up, I couldn't get any sound. What's wrong?

Development Problems

Q. I am developing in Microsoft Visual J++*. When I try to compile an applet that uses Intel Spatial Audio for Java, I get this error message: "spatialAudio is undefined package." How can I fix it?
Q. I am developing using the Sun JDK. When I try to compile an applet that uses Intel Spatial Audio for Java, I get this error message: "Package spatialAudio not found in import." How can I fix it?
Q. I can compile my applet and run it in the my development environment's debugger. So why doesn't it work outside the development environment?
Q. The sample applets run on my system, but when I try to compile my applet I get an error on the import statement. Why?
Q. Can I write Java applications as well as Java applets using the package?

API Questions

Q. I successfully created one or more SoundSources in my applet, but I don't hear anything when the applet runs. What's wrong?
Q. After I run my applet in a browser, I lose all other audio until I close the browser. What's wrong?
Q. When I try to create a second Listener object, the call fails. What's wrong?
Q. Why can't I create a CachedSoundSource from a relative URL?
Q. I have an environment with two Environment objects and one Listener in each. When I run the applet, only one listener works. What's wrong?
Q. I am calling Listener.connect() in my start() method and it returns false the first time, indicating failure. What's wrong?

Advanced Topics

Q. What audio formats are supported?
Q. What MIDI support is provided?
Q. I am trying to control the CPU budget for audio spatialization by setting the CPUBudget for the Environment or for individual Sound Sources, but I don't hear any difference. Am I doing something wrong?
Q. What are the "info" member variables in several of the classes?
Q. When does the data for a CachedSoundSource get downloaded?

Known Problems

A list of known problems for the Intel Spatial Audio for Java package are available here.

Installation and Compatibility Problems

Q: When I try to run an applet that uses Intel Spatial Audio for Java, I get an error message like this: "Applet exception: class <class name> got a security violation: method verification error" or "java.lang.NoClassDefFoundError." What's wrong?
For Windows* 95 and Windows NT*:
Your browser cannot find the classes in the spatialAudio package. Ensure that the file spaud.zip is installed properly:

• For Netscape Navigator, in the [Netscape]\Program\plugins directory.
• For Internet Explorer, in the [WinDir]\Java\Classes directory. The path and the filename must be included in the ClassPath registry key entry under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Java VM. The key will probably include the string: C:\WINNT\java\classes\spaud.zip or C:\WINDOWS\java\classes\spaud.zip.
• For the Sun JDK, in your [Installation Directory]\classes directory. The path and the filename must be included in your CLASSPATH environment variable. If you accepted the default installation directory, an entry similar to this should exist in your CLASSPATH: C:\PROGRA~1\INTEL\JAVA\classes\spaud.zip.

Q: When I try to run one of the sample applets, the Java Console prints a message like "Failed to create the environment" and the applet fails to run. What's wrong?
For Windows 95 and Windows NT:
This can happen if Intel RSX 3D is not properly installed, or if the Intel Spatial Audio for Java libraries are not properly installed.

To verify your installation of RSX, launch the Configuration utility from the Start menu \ Programs \ Intel RSX 3D and click the button that says "Test RSX Audio." If RSX 3D is not functioning properly, try reinstalling Intel Spatial Audio for Java.

To ensure that the Intel Spatial Audio for Java libraries are properly installed, check for the following file locations:

• For Netscape Navigator, spaudNS.dll should be found in the [Netscape]\Program\java\bin directory.
• For Internet Explorer, spaudMS.dll should be found somewhere in your PATH, probably in the Windows\System or Winnt\System directory.
• For the Sun JDK, spaudMS.dll should be found somewhere in your PATH, probably in the Windows\System or Winnt\System directory.

If the files are not properly installed, try reinstalling the software.

Q: When I try to run one of the sample applets, the Java Console prints a message like "Failed to create the listener" and I don't hear any audio. What's wrong?
For Windows 95 and Windows NT:
This can happen if there is no appropriate audio device, or if the audio device is occupied by another application.

You must have a functioning stereo sound card to use this software. If you do not, the listener cannot be created.

Make sure that no other application is using the audio device on your system. Sometimes applications may not always release the audio device. Try rebooting, and run the applet again.

Q: The sample applets seem to be running, but I don't hear anything. What's wrong?
For Windows 95 and Windows NT:
Check the Java Console for error messages. The sample applets are designed to be tolerant of installation problems.

Q: Netscape Navigator 2.0 supports Java. Why don't the applets run in it?
For Windows 95 and Windows NT:
Intel Spatial Audio for Java is currently supported only for Netscape Navigator versions 3.0 and 3.01. Although earlier versions supported Java, some aspects of the support have changed.

Q: Where is the Java Console for Microsoft Internet Explorer?
For Windows 95 and Windows NT:
You won't be able to see the Java console while running applets on Internet Explorer, but you can check it later after you finish running the applets.
Go to the View menu and select Options. Select Advanced and check the box Enable Java Logging. Explorer will create a file called javalog.txt. This file will be stored in C:\windows\java.

Q: I am having problems getting applets to run in one or more supported environments. How can I validate my installation?
For Windows 95 and Windows NT:
See the descriptions above for proper installation of the classes and libraries.

Q: When the installation finished, I was left with a dialog box labeled "RSX 3D - Realistic Sound Experience Configuration Utility." What is it and what is it for?
For Windows 95 and Windows NT:
Intel Spatial Audio for Java uses Intel RSX 3D for audio spatialization, mixing, and rendering. The Configuration Utility allows you to validate your installation of RSX 3D and select whether you prefer to use speakers or headphones to listen to the audio.

Q: My browser crashed. When I brought it back up, I couldn't get any sound. What's wrong?
For Windows 95 and Windows NT:
When an application that is using the audio device crashes, the audio device may be left open. The only way to restore the audio device is to reboot your computer.

Development Problems

Q: I am developing in Microsoft Visual J++. When I try to compile an applet that uses Intel Spatial Audio for Java, I get this error message: "spatialAudio is undefined package." How can I fix it?
For Windows 95 and Windows NT:
Use the menus to choose "Build" \ "Settings." Choose the "General" tab and enter the full path to the file spaud.zip, including the filename, under "Class Path Directories."

Q: I am developing using the Sun JDK. When I try to compile an applet that uses Intel Spatial Audio for Java, I get this error message: "Package spatialAudio not found in import." How can I fix it?
For Windows 95 and Windows NT:
Make sure that the file "spaud.zip" is included in your CLASSPATH Environment variable. The full path and the filename must be included (i.e. "C:\PROGRA~1\intel\java\Classes\spaud.zip").

Q: I can compile my applet and run it in the my development environment's debugger. So why doesn't it work outside the development environment?
For Windows 95 and Windows NT:
Some development environments use their own classpath settings, which may be different than those used by your Java runtime environment. Make sure that spaud.zip is properly installed.

Q: The sample applets run on my system, but when I try to compile my applet I get an error on the import statement. Why?
For Windows 95 and Windows NT:
Some development environments use their own classpath settings, which may be different than those used by your Java runtime environment. See the explanation above for Microsoft Visual J++.

Some development environments may not be able to find classes in the spaud.zip file. Try unzipping the file, preserving directory structure, and including the path to the directory that contains the spatialAudio folder in your classpath.

Q: Can I write Java applications as well as Java applets using the package?
For Windows 95 and Windows NT:
Yes, Intel Spatial Audio for Java functions exactly the same in applets and applications.

API Questions

Q: I successfully created one or more SoundSources in my applet, but I don't hear anything when the applet runs. What's wrong?
For Windows 95 and Windows NT:
First, make sure that you have successfully created a listener. An audio listener is the perceiver of audio for an environment; without a listener, you will not hear anything. Refer to the Tutorial Lesson 2, Setting Up, for help setting up your audio environment.

Second, make sure that your sound sources are in range of the listener. Refer to the Tutorial Lesson 4, The Sound Model, for more information.

Q: After I run my applet in a browser, I lose all other audio until I close the browser. What's wrong?
For Windows 95 and Windows NT:
Your applet may not be releasing the audio device. A good rule of thumb is to call Listener.connect() in an applet's start() method and Listener.disconnect() in the stop() method. You must control your access to the audio device; this is not done automatically for you.

Q: When I try to create a second Listener object, the call fails. What's wrong?
For Windows 95 and Windows NT:
Only one Listener is supported per Environment; attempts to create additional Environments will fail.

However, you may have multiple Environments, each with one Listener. In this case, though, you must make sure that the audio device is available to each Listener when it is created. When you call Environment.createDirectListener(), the Listener is automatically connected to the audio device if it is available; if it is not available, the creation fails. The safest approach is to create the Listener in the first Environment and then call Listener.disconnect() before creating the second one. You can then control the Listeners' access to the audio device individually.

Q: Why can't I create a CachedSoundSource from a relative URL?
For Windows 95 and Windows NT:
Currently, you must provide a fully-qualified URL, or s-String representing such an URL. The URL may reference a file stored on a web server (http://...) or a local file (file://...).

Q: I have an environment with two Environment objects and one Listener in each. When I run the applet, only one listener works. What's wrong?
For Windows 95 and Windows NT:
You should not have this problem with Windows 95 and DirectSound. However, on Windows NT or Windows 95 without DirectSound, audio applications within the same process cannot be shared. This means that only one Listener can be connected to the audio device at a time.

Q: I am calling Listener.connect() in my start() method and it returns false the first time, indicating failure. What's wrong?
For Windows 95 and Windows NT:
Nothing is wrong. When you create a DirectListener, it is automatically connected to the audio device. Since it is already connected, the first call to connect() will fail. However, you should still leave the code in place so that contact with the audio device is reestablished each time the applet starts.

Advanced Topics

Q: What audio formats are supported?
For Windows 95 and Windows NT:
Through Intel RSX 3D, all ACM (Audio Compression Manager) resolvable formats are supported. For optimal performance, use PCM (Pulse Code Modulation) audio data to avoid format conversion.

Q: What MIDI support is provided?
For Windows 95 and Windows NT:
Limited support for MIDI (.mid) files is provided through your platform's native MIDI support. Distance attenuation, but not full spatialization, of MIDI files is provided in this release.

Q: I am trying to control the CPU budget for audio spatialization by setting the CPUBudget for the Environment or for individual Sound Sources, but I don't hear any difference. Am I doing something wrong?
For Windows 95 and Windows NT:
Probably not. These features may not be supported in the underlying audio rendering engine.

Q: What are the "info" member variables in several of the classes?
For Windows 95 and Windows NT:
These variables allow you to store a Java object containing data specific to your application in the spatialAudio class. This may allow you to avoid sub-classing for minor extensions to the classes provided.

Q: When does the data for a CachedSoundSource get downloaded?
For Windows 95 and Windows NT:
Data is downloaded synchronously during the creation of a CachedSoundSource. As a result, creation can be a lengthy process but all data will be downloaded when the method returns.

See the Intel Spatial Audio for Java Release Notes for more information.

This page was last updated on Feb 12th, 1997.

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