Re: webcam support -- first success!!

On Fri, May 20, 2005 at 11:05:56PM +0200, michel Xhaard wrote:
> Peter,
> > > spca5xx is fully compliant with the v4l1 API .To benefit of the jpeg
> > > stream encoded by the hardware we only extend the v4l API with our own
> > > palette jpeg . That way the spca5xx module only add the missing header
> > > and forward the full jpeg stream in user space. For all others palette
> > > the spca5xx module decode the jpeg stream in kernel space with the help
> > > of a tasklet :) ofcourse
> >
> > Hm, does that mean that a standard software (xawtv/camE/motion) would
> > work with the device, or not?
> that works for all apps compliant with v4l1
> for xawtv used
> xawtv -noxv -c /dev/video0 -geometry 320x240 -bpp 32 
> gnomemeeting, ffmpeg works
> camE and motion palantir should work but i never try :)

Thanks a lot, I will try that!

> > I would actually be happy with much less -- the grabbing machine has
> > only 400 MHz (G3 PPC), and it would ideally be able to send the stream
> > live over 11 MBit WLan. And after all, it would be good to serve the
> > stream over DSL upstream to the world.
> 
> too slow for a kernel  jpeg decoding sorry :(

Hm, but not too slow for spcaserv/spcaview -- at the moment the camera
is connected to an old G3 blue/while with 300 MHz. I'm not sure where
the kernel decoding jpeg comes into play... maybe when I start using the
v4l interface?

> > A Java client can become difficult, I have no Java here on Linux on PPC
> > unfortunately.
> I did not like the java client :) Not really an expert but http is not set for 
> video streaming :))

I just discovered the source in the spcaview package, and now I see
better what you mean. It might not be useful for me, but for some people
visiting the site it might be!

> > I just ran
> > 	'./spcaserv -f -s 320x240 -w 7777'
> 
> ERROR here try
> ./spcaserv -f jpg -s 320x240 -w 7777

Oops, looks like a typo. I just checked: it is not a copy and paste
error. That's indeed what I ran.

I tried it again with -f jpg now, but it doesn't make a difference!

Looking closer at the colors, it seems that blue is swapped with
red/yellow... 

Interestingly, if I take a snapshot (with the key 's'),
the snapshot jpg file looks completely normal if I look at it in one of
the usual picture viewers.

> other whise by default spcaserv used yuv420p so the module decompress the jpg 
> video stream and spcaserv recompress !!!
> 
> > 	'./spcaview -f jpg -s 320x240 -w 192.168.0.248:7777 -j -o /tmp/bla.avi'
> Client only need to connect and take the good argument from the tcp/ip stream 
> header so
> ./spcaview -w 192.168.0.248:7777
> is enought :)

I noticed meanwhile. Thanks :)

I think I have an idea for a new feature for spcaview (or spcaserv?):
drop all frames but some, e.g. keeping only a frame every 5 seconds.
Ideally this would be like what -p already allows -- at least when
grabbing directly, but with remote viewing (spcaserv-spcaview) it
doesn't seem to have an effect.

Does spcaview have a mode in which it recieves the stream from the
network without displaying anything?

(Yes, I should try out one of the various webcam programs. I'm just
so curious :)

> > I will send you a "good" log too, if you don't mind, maybe it reveals
> > something different.
> Just read it nothing more sorry :(

Thanks,
Peter
-- 
the pink cardinal got the tasty cardinal