Many other guides suggested camcorder recording with the lens cap to erase a minidv on but this can capture environment activity on the tape. It is possible to create artificial video on the computer and send it to the camcorder to overwrite the media. One or more random passes followed by a zero pass is desirable. Some camcorders may not be able to erase the first half second of tape so a small lenscapping may be desirable.
We want dvcont from package libavc1394-tools and test-dv from libiec61883
test-dv was not incuded in the binary package by default, so edited examples/Makefile.am to include test-dv and debian/libiec61883-dev.install to change /usr/bin/plug* to /usr/bin/* followed by dpkg-buildpackage -rfakeroot
git clone git://git.kernel.org/pub/scm/libs/ieee1394/libiec61883.git /mirror/git/git.kernel.org/pub/scm/libs/ieee1394/libiec61883.git /union/git/git.kernel.org/pub/scm/libs/ieee1394/libiec61883.git/configure --prefix=/union/git/git.kernel.org/pub/scm/libs/ieee1394/libiec61883.bin
dvcont rewind dvcont record /union/git/source.ffmpeg.org/ffmpeg.git/ffmpeg -r 25 -s 720x576 -f rawvideo -i /dev/urandom \ -ar 48k -ac 2 -f s16le -i /dev/urandom -target dv -y /dev/stdout | \ /union/git/git.kernel.org/pub/scm/libs/ieee1394/libiec61883.git/examples/test-dv /dev/stdin
dvcont rewind dvcont record /union/git/source.ffmpeg.org/ffmpeg.git/ffmpeg -r 25 -s 720x576 -f rawvideo -i /dev/zero -ar 48k -ac 2 -f s16le -i /dev/zero -target dv -y /dev/stdout | \ /union/git/git.kernel.org/pub/scm/libs/ieee1394/libiec61883.git/examples/test-dv /dev/stdin
To get an Mpeg stream: dvgrab -format raw | ffmpeg -f dv -i - -target vcd - | vlc -
You can do this in xscreensaver-getimage-video to get frames from the IEEE1394 DV camera on your xscreensaver:
my @programs = ( "dvgrab --format jpeg --jpeg-overwrite --every 25 $tmpdir/webcam < /dev/null " . "> /dev/null 2> /dev/null & C=\$! ; sleep 1; kill \$C; ". "mv $tmpdir/webcam.jpg $tmpfile", # IEEE1394 camera