KDE4 and video acquisition

[Dave Feustel]

On Friday 20 January 2006 15:20, Laurent Pinchart wrote:
> Hi everybody,
> 
> with all the development effort going in KDE4 (and renaming kdemm to Phonon 
> must be a sign that developers are active on the project, isn't it ? :-)), I 
> thought I would rise the issue of video acquisition.
> 
> I recently wrote a Linux device driver for new generation webcams. After a few 
> weeks of development and some tests with a very simple V4L2 command line 
> application, I thought I would try live video streaming. Finding an 
> application which would support the webcam turned out to be much more 
> difficult than I would have expected. Either V4L2, MJPEG or both were not 
> supported in the application, when things were not even worse. That's when I 
> found out that video acquisition support in Linux is far from being perfect, 
> or even easily usable at all.
> 
> Application currently have to support V4L and V4L2 with various streaming 
> methods (read, mmap, ...), need to implement conversion from all possibles 
> image formats that webcams generate (RGB, YUV, MJPEG, PWC, ...) and even have 
> to work around driver or hardware bugs. That situation is clearly suboptimal.
> 
> As KDE developers are busy creating an architecture for the multimedia 
> framework in KDE4, I was wondering if any of you have thought about webcam 
> support. Everything I read about Phonon states that sound will be supported 
> through various backends (GStreamer, NMM or MAS), but the video input has not 
> been publicly discussed so far. With all the controls that a webcam can 
> expose (brightness/contrast/hue/saturation, but also exposure time, gain, 
> power line frequency setting, pan/tilt/zoom, iris, ...), the job is not 
> trivial.
> 
> All constructive comments are welcome :-)

Hawking Technology makes an inexpensive webcam (HCN210) that
uses MJPEG. I'm interested in this camera for use with OpenBSD 
because it has an ethernet-based web interface which makes moot the 
question of usb support.

Dave Feustel
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