v4l needs to be enabled in vlc.

running vlc to load webcam it reports:

[00000288] main access warning: no access2 module matching "v4l" could be loaded
[00000285] main input error: no suitable access module for `v4l:/dev/video0:norm=secam:frequency=543250:size=640x480:channel=0:adev=/dev/dsp:audio=0'


from this page:

http://www.videolan.org/doc/videolan-howto/en/ch08.html


you get:

Note
You must add --enable-v4l to ./configure to use this feature.


and the configure in PKGBUILD of vlc is:

./configure --prefix=/usr --enable-dvdread --enable-dvdnav --enable-madi \
--enable-ffmpeg --disable-rpath --enable-wxwindows --enable-faad \
--enable-alsa --enable-skins2 --enable-livedotcom --enable-dvb \
--enable-dmo --with-livedotcom-tree=/usr/lib/live-media \
--with-ffmpeg-faac --with-ffmpeg-vorbis --with-ffmpeg-dts \
--with-ffmpeg-ogg $EXTRAFEATURES


I added the option --enable-v4l:
- compilation worked
- a new tab appeared in the open dialog
- now i can use the webcam :)


conclusion:
"--enable-v4l" should be added to the PKGBUILD of vlc, specially since vlc is the app that everybody recommends you to use in order to make video streaming.