[AG-TECH] Re: interesting discussion on ag-techs about omvic on mac's

Wesley Miaw wesley at bmrc.berkeley.edu
Sat Aug 2 15:16:32 CDT 2003


With regards to the recent discussion on camera drivers and omvic on 
Mac OS X:

The Orange Micro driver (which is a wrapper around Apple's driver) will 
not work. I was unable to figure out how to make it work--it doesn't 
seem to support the low-level API I am currently using.

The most recent IOXperts driver will not work. Something broke between 
1.5 and 1.6 of the old, non USB-FireWire combo driver and discussions 
with IOXperts and myself were unable to resolve the issue. The new 
USB-FireWire combo driver appears to carry over this incompatibility.

The old IOXperts FireWire 1.5 driver does work. This driver should be 
available through VRVS and possibly off the Open Mash web site.

Notes from IOXperts only iChat AV and iSight incompatibility indicate 
that Apple is discouraging third-party developers to support iChat AV 
on systems that will not produce the highest-quality results. Namely 
USB cameras. It is not necessary to uninstall the IOXperts driver to 
make use of iSight and iChat AV, however, as you are given the option 
of choosing your video and audio capture devices and drivers in the 
iChat AV perferences.

There are third-party workarounds to get USB cameras to work with iChat 
AV. A Google search should turn them up.

For those who are interested, the reason I used the lower-level API, 
which seems to be the cause of all the driver incompatibilities, is 
because Mash does everything internally as YUV. The higher-level API 
does not provide the YUV colorspace, and would require converting each 
frame from some form of RGB to YUV. Apple did not appear to have 
built-in conversion routines to do this, which might be fast enough. At 
this point, however, it seems like that might be the only way to ensure 
driver compatibility. An older version of video-macosx.cc in CVS has 
notes on implementing this. Things may also have changed with QuickTime 
6.1, however I did not see anything I thought would help address the 
problem when I read through the release notes.

Hope this helps,
--
Wesley Miaw, Berkeley Multimedia Research Center
wesley at bmrc.berkeley.edu




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