meye.txt

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Vaio Picturebook Motion Eye Camera Driver Readme
------------------------------------------------
	Copyright (C) 2001 Stelian Pop <[e-mail]>, Alc魐e
	Copyright (C) 2000 Andrew Tridgell <[e-mail]>

This driver enable the use of video4linux compatible applications with the
Motion Eye camera. This driver requires the "Sony Vaio Programmable I/O 
Control Device" driver (which can be found in the "Character drivers" 
section of the kernel configuration utility) to be compiled and installed
(using its "camera=1" parameter).

It can do at maximum 30 fps @ 320x240 or 15 fps @ 640x480.

Grabbing is supported in packed YUV colorspace only.

MJPEG hardware grabbing is supported via a private API (see below).

Module options:
---------------

	gbuffers:	number of capture buffers, default is 2 (32 max)

	gbufsize:	size of each capture buffer, default is 614400

	video_nr:	video device to register (0 = /dev/video0, etc)

Module use:
-----------

In order to automatically load the meye module on use, you can put those lines
in your /etc/modules.conf file:

	alias char-major-81 videodev
	alias char-major-81-0 meye
	options meye gbuffers=32

Usage:
------

	xawtv >= 3.49 (<http://bytesex.org/xawtv/>)
		for display and uncompressed video capture:

			xawtv -c /dev/video0 -geometry 640x480
				or
			xawtv -c /dev/video0 -geometry 320x240

	motioneye (<http://www.alcove-labs.org/en/software/meye/>)
		for getting ppm or jpg snapshots, mjpeg video

Private API:
------------

	The driver supports frame grabbing with the video4linux API, so
	all video4linux tools (like xawtv) should work with this driver.

	Besides the video4linux interface, the driver has a private interface
	for accessing the Motion Eye extended parameters (camera sharpness,
	agc, video framerate), the shapshot and the MJPEG capture facilities.

	This interface consists of several ioctls (prototypes and structures
	can be found in include/linux/meye.h):

	MEYEIOC_G_PARAMS
	MEYEIOC_S_PARAMS
		Get and set the extended parameters of the motion eye camera.
		The user should always query the current parameters with
		MEYEIOC_G_PARAMS, change what he likes and then issue the
		MEYEIOC_S_PARAMS call (checking for -EINVAL). The extended
		parameters are described by the meye_params structure.


	MEYEIOC_QBUF_CAPT
		Queue a buffer for capture (the buffers must have been
		obtained with a VIDIOCGMBUF call and mmap'ed by the
		application). The argument to MEYEIOC_QBUF_CAPT is the
		buffer number to queue (or -1 to end capture). The first
		call to MEYEIOC_QBUF_CAPT starts the streaming capture.

	MEYEIOC_SYNC
		Takes as an argument the buffer number you want to sync.
		This ioctl blocks untils the buffer is filled and ready
		for the application to use. It returns the buffer size.

	MEYEIOC_STILLCAPT
	MEYEIOC_STILLJCAPT
		Takes a snapshot in an uncompressed or compressed jpeg format.
		This ioctl blocks until the snapshot is done and returns (for
		jpeg snapshot) the size of the image. The image data is 
		available from the first mmap'ed buffer.

	Look at the 'motioneye' application code for an actual example.

Bugs / Todo:
------------

	- overlay output is not supported (although the camera is capable of).
	  	(it should not be too hard to to it, provided we found how...)
		
	- mjpeg hardware playback doesn't work (depends on overlay...)

	- rewrite the driver to use some commun video4linux API for snapshot
	  and mjpeg capture. Unfortunately, video4linux1 does not permit it,
	  the BUZ API seems to be targeted to TV cards only. The video4linux 2
	  API may be an option, if it goes into the kernel (maybe 2.5 
	  material ?).