motion uses a video4linux device for detecting movement. It makes snapshots of the movement which can be converted to MPEG movies in realtime (or later for low CPU usage), making it usable as an observation or security system. It can take actions like sending out email and SMS messages when detecting motion.
The video4linux loopback device is a device driver which generates video pipes. It allows a user program to feed a video stream to another as if it were coming from an actual video device. It can be used for video filters, or for realtime viewing of the output of the "motion" program.
Re: Why didn't you asked this on the linux-kernel mailinglist????
> If you read the text detailed, it's
> just a temporary solution, and that
> solution leads to the opening of specs
> or releasing drivers with source code...
> IT'S NOT PERMANENT!
It is not a temporary solution, otherwise you
wouldn't need an API that didn't change between
versions. And why should a manufacturor release
any specs if he can just use the API indefenitly?
Why didn't you asked this on the linux-kernel mailinglist????
If you had read some archives of linux-kernel you
would know why this doesn't work:
1 A 'stable' api means that you will be stuck with
old mistakes for a long time, there is a reason
why kernel interfaces change, namely to make them
2 You are making it easier for the manufacturors
to make binary only drivers, and thus they will
never need to give their specs away. This might
work well if you have a popular system. But don't
expect them to release a driver for x86, ppc, arm,
mips, superh or whatever linux runs on this week.
3 You already don't have to work on the kernel for
writing a device driver, when making a modular
driver you only have to know a few kernel
functions that you have to call.
I have written several drivers and know almost
nothing (but learning) about the inner works of
4 Building layer upon layer upon layer will make
your driver slower and slower and slower.
5 Most important: Linus doesn't like it :)