Q: Hello-- I'm trying to use Raven 1.2.1 (with the latest updates) on a Macbook (not Pro, running OSX 10.4.6 w/ 2GHz Intel Core Duo and 2GB RAM). I'm trying to record with an external device. I can open a new recording window. When I hit "record" Raven spontaneously disappears. I've tried this both with the internal mic and an external source with the same results. I've tried this on two different Macbooks--same results. It works fine on a G4 Powerbook. Can anyone confirm this behavior? And any ideas of a solution?

A: Apple has a bug in some of their software. The workaround in Raven to be able to record on an Intel Mac is to put this line in your RavenPreferences.txt file.

raven.audioInput.native=false

This will cause Raven to use Java Sound for input, which will bypass the bug in the Apple software. When you run Raven with Mac native audio input, the devices show up as "Built-in Mic" or "Built-in Input". When you run with non-native audio input (Java Sound), the device shows up as "Mac OS X, CoreAudio, Audio hardware". When running Raven 1.3, all device types will show up so you can choose between then without having to specify a line in the RavenPreferences.txt file.

A: USB devices are handled by Core Audio on Mac computers; however, Apple's Core Audio implementation for Java on Intel-based Macs causes problems for Raven. On these machines, Raven can only receive input through the built-in microphone or line-in depending on OS sound configurations. An Apple Java bug causes all other input devices to crash Raven upon recording.

Until Apple resolves this bug, you can only use a USB audio device on an Intel Mac if it has audio outputs that can playback the input directly, serving as a preamp for the signal:

1) Connect the USB device to the computer for power
2) Connect the audio output of the USB device (either the headphone output or RCA outputs) to the line-in of the Mac
3) Select "MacOS" as the input device in Raven

Thanks to Robert Rayle of the Museum of Science in Boston for this workaround.

On Leopard OS (10.5), external devices could be used via Javasound in certain cases. Sending your results with this could help us find a better solution.

A: Raven uses Java Sound for audio that currently limits the sample rate of playback to 200kHz. Therefore, for example, Raven can play a 44.1 kHz sample rate file at 4x speed but not at 5x as the accelerated playback sample rate would exceed this limit. Attempting to play over the limit on Raven 1.3 Build 16 and below will occasionally freeze the program. Later Raven builds will alert the user and stop play.

The Raven team is considering implementing resampling functions to help users skim over long recordings using accelerated playback without exceeding the sample rate limit. Users who are interested in doing so now can resample recordings with another application before playing in Raven.

A: Raven reads a full page at a time. If there is only a partial page at the end of the sound, Raven will reuse some of the previous page to create a full page. When you use the scroll bar for the paged display, you are paging to the end of the sound, then subtracting the page size from the end to see where the page should start.

A way to get around this problem is to go to the last page of the file, then use the "Configure View Axes" menu item on the View menu (or in the context-sensitve menus within the views). In the above example, the user should type 60 for the time position in the dialog. This will move the start of the view to the 60-second position, allowing her to print the final 7 seconds of her sound.

1. One "kU" is one thousand Raven amplitude units ("U"'s). One "U" is the smallest amount of sound the digital recording can represent, the resolution of the recording (or one least significant bit). The resolution depends on the number of bits per sample, or bit depth, in the digital representation of the sound. An 8-bit sample can resolve 256(=2^8) different amplitude values; a 16-bit converter can resolve 65,536(=2^16) values. For an 8 bit signed recording, Raven's y-axis ranges from -128 U to +127 U (256 divisions). For an 16 bit signed recording, Raven's y-axis ranges from -32768 U to +32767 U (65,536 divisions). It is possible to calibrate your instrument chain to determine a multiplicative conversion factor between Raven's "U"'s and real would units such as volts or uPa.

2. Spectra power levels are referenced to unity power.

A: Raven runs in a Java Virtual Machine (JVM) which needs to allocate space when it launches. The Memory Manager sets the maximum heap size for the JVM. When Raven starts, if the JVM is not able to allocate enough space, then Raven will not start.

On Mac OS X, you can just launch /Applications/Utilities/Console, then look to see the message that gets issued when you try to launch Raven. It will likely be "Error occurred during initialization of VM. Could not reserve enough space for object heap."

On Windows, try launching using RavenConsole.bat in the "Raven 1.2" folder. This will launch a command window, and we may see an error message there. If the window disappears, then you'll need to open a command window first.

Start > Programs > Accessories > Command Prompt

then type the following:

cd "\Program Files\Raven 1.2"

then type

RavenConsole

You will likely see something like the following:

Microsoft Windows XP [Version 5.1.2600]
(C) Copyright 1985-2001 Microsoft Corp.

C:\Program Files\Raven 1.2>RavenConsole

C:\Program Files\Raven 1.2>jre\bin\java -Xmx2000M -Xbootclasspath/p:AiffFileWrit er.jar -cp
Raven12WinFixes.jar;Raven12Fixes.jar;Raven12Plus.jar;Raven12Win.jar;R
aven12Base.jar;mail.jar;activation.jar;jai_imageio.jar
clo.brp.raven.Application

Error occurred during initialization of VM
Could not reserve enough space for object heap

To solve this problem, you need to change the files that the Memory Manager updated when you set the high max heap size. There is one file on Mac OS X, there are two files on Windows with Raven 1.2.1, and there is one file on Windows with Raven Pro 1.3.

Mac OS X

The file to change is Info.plist within the Raven application. Locate the Raven application within the Raven 1.2 folder. Right-click (or Control-click) on the Raven icon, then select "Show Package Contents" from the menu. You should now see a folder named Contents. Within this folder is a file called Info.plist. Edit this file using the text editor, and search within the file for -Xmx. Change the -Xmx2000M to -Xmx512M.

<key>Java</key>
<dict>
<key>VMOptions</key>
<string>-Xbootclasspath/p:Raven.app/Contents/Resources/Java/AiffFileWriter.jar -Xmx2000M -Xbootclasspath/a:Raven.app/Contents/Resources/Java/CoreAudioSupport.jar</string>
<key>MainClass</key>
<string>clo.brp.raven.Application</string>
<key>JVMVersion</key>
<string>1.4+</string>

Windows

There are 2 places where memory heap size is set in Raven 1.2.1. You can right-click on either file and edit it with Notepad. Both are in C:\Program Files\Raven 1.2.

RavenConsole.bat

Change -Xmx2000M to -Xmx512M

RavenLauncher.lax

Look for the following lines. You can just search on Xmx, then change the number from 2000M to 512M. It's listed as 256m below (from my machine).

# LAX.NL.JAVA.OPTION.ADDITIONAL
# -----------------------------
# Sets the maximum heap size of the Java virtual machine for use by Raven. Specify 256m for 256 megabytes.

lax.nl.java.option.additional=-Xmx2000m -Xbootclasspath/p:AiffFileWriter.jar

There is one place in Raven Pro 1.3 on Windows to set the maximum heap size. Look in the file C:\Program Files\Raven 1.3\Raven.ini.

Raven.ini

Change -Xmx2000M to -Xmx512M 

Q: Could you tell me the name of the attachment I need to import songs from a Sony Tape recorder into my G4 Mac to analyse the bird songs with Raven?

A: It depends on the types of output connections that you have from your recorder, and on the types of input connections that you have on your computer. Some solid state digital recorders will record to WAV files, in which case you only need to copy those files onto your computer. For digital tape recorders, you may be able to use the digital output port of the recorder connected to a digital in on your computer or sound card. For this case, you'll still need to acquire into Raven, but you won't be redigitizing.

In most other cases, you'll need to digitize using the computer's sound card or sound system, then record into Raven. Typically, you can use a double male-ended phono cable (both ends look like the end of a headphone jack). One end would plug into the line out from the tape recorder, the other end into line in on the computer. If you have only headphone out on the recorder and microphone in on the computer, then you may need an attenuator on the connection cable. This will help to lower the gain on the signal so that you don't clip any of the signal as you digitize it. Radio Shack sells a headphone connector cable with a volume control right on the cable. This can double as an input attenuator. Your double-male-ended cable would plug into the headphone connector cable. I'll take a look on the radioshack.com site to see what they have.

Model: 42-2559 is the gold-plated volume control cable for stereo headphones. This is the attenuator.

Model: 42-2497 is a 1 ft. sheilded stereo audio cable for connecting the computer to the recorder.

Model: 42-2420 is a 6 ft. shielded cable (probably not stereo)

You would use 42-2559 with either 42-2497 or 42-2420. This is what I used at the Macaulay Library Natural Sounds Recording Workshop this year to transfer recordings to computers.

Model: 42-2152 appears to be the combination cable that includes attenuation. You could use this all by itself, but I haven't used it myself.

The last 3 I found by searching on "cable" on radioshack.com then drilling down into A/V cables then patch cables. You could likely use a mono cable instead of a stereo cable, but the stereo cable shouldn't hurt. You should be able to find all 4 above by searching the entire radioshack.com site for those model numbers.

Once you've attached the recorder to the computer, you should be able to follow along in the Raven User's Manual to do your recording. Select File > New Recorder, select an input device from the dialog, and press OK. Press the little gree arrow button at the bottom of the window to start recording. Start playing your recording, and you should see some activity in the waveform and spectrogram views of Raven.

If you could previously send email feedback to the Raven team and can no longer do so, it is likely that the SMTP server which Raven was using to send its feedback is no longer accepting these types of messages. On 1 February 2006, Cornell University is changing its authentication on many of its mail servers to require authentication when sending. A future version of Raven will be shipped so that the default SMTP server through which to send is appsmtp.mail.cornell.edu. In the meantime, you can reconfigure your copy of Raven by setting the following line in your RavenPreferences.txt file:

raven.feedback.smtpServer=appsmtp.mail.cornell.edu

New Macs are built using the Intel processors, but older Macs (G4, G5, PowerBook) were built using PowerPC processors. To run a Java application like Raven Pro, the application needs a JavaApplicationStub to launch. With the introduction of the Intel platform, Apple introduced what's called a "universal binary" that is supposed to run on either hardware platform, but the universal binary version of JavaApplicationStub does not work with all older Macs because of its use of some libraries that do not exist on these older computers running early versions of Mac OS X. Refer to the thread below for a solution to this problem.

http://help.ravensoundsoftware.com/forum/showthread.php?t=155