Frequently Asked Questions
Common things to do
Please follow these steps if you encounter a problem - either
if it's not listed below or if the steps listed there didn't help:
Check your USB cables. Restart macam. Unplug and replug the device.
Make sure you have the latest version of Mac OS X. Connect the
camera directly (without USB hubs) to a built-in USB port of your
computer (not to a third-party host adapter). Check in the release
notes, the latest news section and the notes on your camera if
it is a known problem.
Problem: No video, no message
Check that your camera is one of the supported cameras.
Message: Camera used by another application
Quit all other running applications. Quit the Classic environment.
Unplug and replug your camera. Restart macam.
Message: Not enough USB power
Plug your camera directly into an USB port of your computer or
into a self-powered USB hub (one with a power adapter).
Message: Not enough USB bandwidth
Unplug other USB devices or plug them into a different USB port
of the computer. Lower the image format, frame rate or increase
the compression if available.
Message: Not enough CPU power
Retry grabbing video. If you encounter the problem frequently:
Quit other applications. Do less things that consume computing
power. Use less cameras at the same time. Lower the image size
or frame rate. Buy a faster Macintosh...
Message: Not enough memory
Restart macam or your video application. Quit other applications.
Increase your computer's RAM. Recompile macam after removing all the
files for cameras that you do not own.
Audio is not handled by the driver but by Mac OS X's own USB
audio drivers (if it's handled at all). Please look into the documentation
Problems installing macam.component
Please make sure you use the QuickTime folder in the Library
directly in the root level of your hard disk (do not mix up libraries
at other locations). Make sure you have administration privileges.
Move older copies of macam.component or webcam.component to the
Trash prior to installing the new one (if you encounter problems
deleting the files: It will work after a restart). Try running
without other components (move them temporarily to another location
Program freezes, Kernel panics, really weird things
Contact the author. Provide detailled information. Help debugging.
Wait for the next release...
Why can't I use my webcam with other applications?
You can. Please copy the macam.component into the /Library/QuickTime/
directory (for access by all users on the system) or into the
~/Library/QuickTime/ (for access by only that user). If you have
a previous copy, please delete it first. A restart is usually
not needed, but if you have trouble, it's a good thing to try.
To verify that your installation works, test with a simple program
such as HackTVCarbon, VideoViewer, or BTV.
Why doesn't iChat recognize my camera?
For some reason, probably pertaining to some minimum acceptable
(Apple) quality level, iChat will not work with regular USB webcams.
It works fine with iSight and the built-in cameras in the Intel-based
notebooks (which are USB devices). There is a solution however,iChatUSBCam
is the name of a shareware program which seems to work for many
users. In the long-term, I recommend that users who are inconvenienced
by this Apple policy send in a feature enhancement request for
iChat (or, perhaps more properly, file a bug report).
What are the minimum requirements for running macam?
Generally, if you can run Mac OS X, you can run macam. macam
does not usually need much memory. Sometimes it does need a lot
of processing power to decode the image stream from the camera.
This also depends a lot on the particular camera being used, so
it is impossible to give a specific MHz or something like that.
Also, if a larger image size is too slow, then a smaller image
size will usually work better.
Why doesn't the sound work?
macam focuses on video. Cameras that have microphones almost
universally use USB Audio Class for sound. This enables the system
software driver to use the camera microphone while macam handles
the video. The macam application does not record sound for movies,
this is a deliberate choice [what should it sound like at 10x?].
The macam component lets the system deal with sound. Look in the
Sound Input pane of the System Preferences, even if it says "Unrecognized
Microphone" (or something similar), you can still use it.
The camera is just not providing a proper name for the microphone.
Can you include <put your camera type in here> support
in your driver?
Generally, no - not because we don't want to, but usually we
don't have such a camera for testing available and we don't have
the necessary developer documentation. If you can provide me with
both, contact us.
Can you build a Mac OS 9 version of macam?
No, sorry. Mac OS 9 and Mac OS X are very different when it
comes to communication with external devices. Converting macam
to Mac OS 9 would probably be more work than developing a driver
from scratch. [Is anyone still asking this?]
Why are only these video sizes and frame rates supported on the
Philips cameras? The OS 9 driver could do better!
The supported frame rates and video sizes are those which can
be received from the camera as uncompressed data. For higher sizes
or frame rates, the USB data bandwith is not sufficient and therefore,
the camera has to reduce the amount of data by using an image
compression algorithm. It's theoretically and technically possible
to support these compressed modes, but it's probably a legal one
because it's a proprietary Philips algorithm. Implementing it
would require to copy copyrighted material (if you're a lawyer
and can give us good advice, please let us know...).
If I open macam and have a camera connected, nothing happens.
What is wrong?
Please check if your webcam is one of the supported webcams
(to find out, look into the Help facility of the macam application).
Try to connect the camera directly, not via hub. Try to connect
the camera to a built-in USB port, not to a third party extension
I get error messages instead of video. What's wrong?
See macam's Help facility for troubleshooting info.
I cannot create compressed QuickTime movies with BTV. Why?
I am currently investigating this. It does work on most systems,
but there are cases where it doesn't. If you have more detailled
info about the cause or when this happens, please tell me.
When I start grabbing video, the image is black and takes a time
to lighten up. Why?
This is a standard behaviour of the cameras. I don't have the
necessary documentation to circumvent this.
I get Kernel Panics. What are you doing with my system?
Believe me: Nothing. The driver runs completely in user space
and therefore shouls not produce kernel panics. This seems to
be an OS bug. Please write down the message (or take a photograph)
and mail it to me along with a detailled description about what
you did when you encountered this and your system configuration.
I will try to find the cause and contact Apple to find a solution.
When I use your driver, I get garbage on the screen and my machine
freezes. What is this?
This is called a "Kernel Panic" and is something that
should never happen. Please see the question above.
I have problems not listed here. What can I do?
Please read the readme file and the news on the home page carefully
as they contain important hints. Try to follow the instructions
and notes as closely as possible.
I have followed the instructions and notes as closely as possible.
Still the same problems. What now?
E-Mail us with a description of your problem, what exactly you
did when the problem occured and a description of your system
setup - as detailled as possible. Most likely you just have encountered
a bug. I will try to fix that.
I am a programmer and would like to extend your driver to support
another camera. Is that ok?
Sure. The source code is included - it is Open Source. Please
follow the GPL and contact me so we can coordinate development.
Can you give me hints about USB or QuickTime programming?
Probably no. I'm no expert in that either. The best resource
I know is the Apple developer technical web site: http://developer.apple.com/technical.
They also have mailing lists for these topics.
I want to participate development. What can I do?
There's much you can do - it depends on your skills and motivation.
Of course, there's programming to do, but there are many other
tasks: documentation, interface design, user assistance, beta
testing and much more. If you want to join our group, please let
Why has "wc" and "webcam.component" been
renamed to "macam"?
For three reasons: 1. I wanted the application and the component
to have more similar names, 2. "wc" was not too informative
("macam" is not much better, but a bit) and 3. (most
important) there was an annoying naming conflict. On UNIX, "wc"
is commonly known for "word count", a command-line tool.
I'm a Philips employee and want to send you documentation about
our cameras. Where to?
Thanks! My postal and email addresses are included at the very
end of the readme file.