Phillips SPC900NC camera not detected after restart with1.1.2a27 drivers.

[Steve Sisak]

At 1:25 PM +0100 2/28/07, Andi Schwelling wrote:
>James schrieb:
>>I tried the 1.1.2a27 logging drivers and did not have the problem 
>>with it failing to recognize the camera after a restart. Still it 
>>would be nice to have it working in the non-logging driver too.
>
>I know this problem sporadically from the first time I installed my 
>SPC900NC and the driver. It seems the device driver isn't loaded at 
>system start, or it does not recognize the cam in that early state 
>of system boot and dies.
>In this case it helps (for me) to start
>  /Library/Application Support/IOXperts/Private/ioxdeviced
>by hand from Finder and the cam gets recognized.

That's useful information (and makes sense). Can anyone else who sees 
this problem see if Andi's solution works for them?

(This won't work correctly for fast user switching, or across logout, 
but relaunching it if you switch user should work)

Also, check system.log and /Library/Logs/CrashReporter for any 
mention of ioxdeviced

I'd be interested in knowing if anyone sees this problem on any 
device other than a webcam based on the Philips chipset (this would 
include Logitech QC Pro 3000-4000 series and white QG for Notebooks 
Pro, but not the QC5000 or newer or black QCfNbP).

If the problem is isolated to the Philips that give me a narrower 
area in which to look.

-----

For your reference, let me explain a bit about what's going on:

IOXperts' leaves 2 daemons running in order to provide 
device-specific preferences, serial number checking, and a way to 
IOXperts CameraControl to talk to the driver in other applications, 
so that you can change video settings while streaming and in 
applications that don't allow access to the standard video settings 
dialog.

ioxdeviced is a standard unix daemon that provides device-specific 
preferences, device initialization, and acts as a traffic cop to 
manage access to a given device from different applications.

Because it is a daemon and runs outside a user's login session, it 
can't receive AppleEvents or access QuickTime or present any user 
interface (it's limited to the CoreSerivces API).

ioxsessiond is installed as a global login item, running in the 
user's login session -- it provides services that can't be done from 
a daemon (like UI) and acts as a interface for the driver to forward 
requests to ioxdeviced as needed.

In the case of Fast User Switching, there is a separate instance of 
ioxsessiond running in each user's login context -- they use 
ioxdeviced to coordinate with each other.

(Supporting Fast User Switching is very messy as the instances of 
ixosessiond have to count events to see which one is the current user 
and there are many race condition)

For completeness, the "driver" (IOXperts Webcam.component) is a 
QuicTime Video Digitizer component, an instance of which potentially 
runs in any application which uses QuickTIme.

Note that if you launch ioxdeviced manually, it will run in your own 
login session rather than the system context and will be terminated 
if you logout and may not be accessible if you switch user.

-----

It sound like ioxdeviced is either crashing of not launching as a 
result of an error.

The reason I asked about wether this is specific to the Philips 
chipset is that ioxdeviced performs the additional step of putting 
these cameras into low power mode (light off) when connected (the 
driver then turns the camera on or off as needed).

Since the Mic in the camera is controlled by the system USB Audio 
Class driver, I'm wondering if there's a race condition where 
ioxdeviced and the audio driver are trying to talk to the camera at 
the same time and, as a result ioxdeviced gets an error and fails to 
launch -- logging may cause enough a delay to prevent this from 
happening.

In any case, please let me know what you find.

Thanks,

-Steve
-- 
_________________________________________________________________________
Steve Sisak, CTO                                 steve.sisak at ioxperts.com
IOXperts, Inc.                                     voice: +1 617 876-2572
87 Bristol St #3A                                    fax: +1 617 876-2337
Cambridge, MA 02139                               mobile: +1 617 388-6476