Re: Webcam

From: John Stolz (china-rider_at_wanadoo.fr)
Date: 01/08/05 

Date: Sat, 08 Jan 2005 10:51:31 +0000

On Sat, 08 Jan 2005 14:43:24 +1100, Tim McCoy wrote:

> On Fri, 07 Jan 2005 10:16:29 +0000, John Stolz wrote:
>
>> I have a Philips 740 webcam which seems to work fine when I use
>> camstream, but when I try and runxawtv (3.93) I get the
>> following error:
>>
>> This is xawtv-3.93, running on Linux/i686 (2.6.8.1-12mdk)
>> /dev/video0 [v4l]: no overlay support
>> v4l-conf had some trouble, trying to continue anyway
>> ioctl: VIDIOCMCAPTURE(frame=0;height=120;width=160;format=7):
>> Invalid argument
>> ioctl: VIDIOCMCAPTURE(frame=0;height=288;width=352;format=15):
>> No such file or directory
>> ioctl: VIDIOCMCAPTURE(frame=0;height=288;width=352;format=15):
>> No such file or directory
>>
>> using the -remote option in xawtv gets me:
>>
>> This is xawtv-3.93, running on Linux/i686 (2.6.8.1-12mdk)
>> ioctl: VIDIOCMCAPTURE(frame=0;height=120;width=160;format=7):
>> Invalid argument
>> ioctl: VIDIOCMCAPTURE(frame=0;height=288;width=352;format=15):
>> No such file or directory
>> ioctl: VIDIOCMCAPTURE(frame=0;height=288;width=352;format=15):
>> No such file or directory
>>
>> I have a Dell latitude with an ATI Rage mobility graphics chip.
>> The video device is present (/dev/video -> /dev/video0) and the
>> hardware is recognised (everything works fine in camstream)
>> I'm on Mandrake 10.1. official, kernel 2.6.8.1-12mdk.
>> I'd be grateful to be pointed in the right direction.
>
> Nice timing - we've been playing with these issues for a Holiday project
> lately.
>
> The Philips webcams use the "pwc" kernel driver. This (until recent
> kernels) gives 288x352 images. Most of these cams are capable of 640x480,
> which is only available using the "pwcx" driver - a binary decompression
> module. Unfortunately, its active development has been abandoned. But if
> you're comfortable compiling a custom kernel, you'll do well with 2.6.4,
> using a patch thats available here.
>
> http://www.smcc.demon.nl/webcam/
>
> The issue with XAWTV is that it generally tries to get max res without
> playing nicely. So you'll need to change a few params to keep it back to
> 288x353, or get "pwcx" working.
>
> With an app such as "camorama", you'll probably find you won't be able to
> get the "larger" sized image, which is basically the problem xawtv has.
>
> Cheers
>
> Tim
>
> PS: the binary pwcx functionality has apparently now been built into the
> standard pwcx driver, so a VERY recent kernel (>= 2.6.9) may resolve
> things entirely, without the need to patch and twiddle.

Tim, thanks I'll go have a play - I never compiled a kernel before (at
least not one that worked ;-), time to get my hands dirty.