libgphoto2/camlibs/aox/README

This driver will download pictures from the Concord EyeQ Mini. This camera
has Vendor:Product number 0x3e8:0x2182 and is one of several cameras occupying 
the entry level in the digital camera market, as do the SQ905 cameras. I 
mention the SQ905 cameras because the Concord EyeQ Easy has been reported to 
me as an SQ905 camera. So that is how I obtained this creature, by accident. 
I went to WalMart hoping to find an SQ905 camera which would do 640x480. I 
found a Concord EyeQ Mini, thought it was probably the same thing as a 
Concord EyeQ Easy, bought it, brought it home, and found out it was something 
altogether different. Well, then, I just had to make it work...

The chip inside the camera is unknown, but the .inf file provided with the
camera calls it an "Aox." Apparently, Aox is the same company as Endpoints,
Inc. The chip may be an Endpoints SE401 or SE402. 

According to its manual, the camera can be used as a webcam, or to shoot a 
short video sequence. AFAIK both of these features require kernel module 
support in order to be used properly, and those features are not addressed 
here. This camera library provides a driver for the Concord EyeQ Mini as a 
still camera. 

For those interested in the webcam features, there do exist Linux kernel drivers 
for webcams with SE401 (module "se401") and SE402 module "epcam"). Those 
drivers do indeed support cameras with Vendor number 0x3e8, but Product number 
0x2182 is not listed in their source files. Furthermore, the mere act of adding 
the number and re-compiling the kernel module does not seem all by itself to 
make this camera work as a webcam. The author of these two kernel modules has 
stated to me in e-mail that Endpoints was willing to share some information 
with him about how to access the SE401 and SE402 chips in webcam mode. However, 
my own request for similar information about the still camera functionality has 
not been answered, as of 11/04/03. This camlib, therefore, has been constructed 
by means of close observation of the camera, combined with guesswork. 

Features and quirks of the camera:

The camera has two sizes of pictures. The high-resolution pictures are
640x480 pixels. Their data format is a Bayer array, from which it is
possible to create a PPM image. The camera holds a maximum of 23 pictures in
high-resolution mode. The manufacturer's driver creates JPEG compressed 
images from the downloaded data, and the user is certainly free to do same. 
Here, high-resolution pictures will be saved in PPM format. 

The low-resolution pictures are 320x240. According to the manual, these
pictures are compressed in the camera and are downloaded as JPEG images.
However, the JPEG compression used is a bit non-standard and can not be
decompressed with standard tools. Thus, it is currently not possible to make
pictures from the resulting files. You can just download them. Or, better
yet, figure out what the format is and let me know. The low-compression
data download is not of fixed size, but may vary from one picture to the
next. All low-resolution photos will be saved as RAW files, until such time 
as they are better understood. 

If you have a random mixture of low-resolution and high-resolution photos on
the camera, then the camera will always download the low-resolution pictures
first and the high-resolution photos only after that. In other words, in
that situation the pictures will not be downloaded in the order in which you
took them. 

The camera also supports "video clip" mode, in which the camera keeps taking 
frames so long as one holds down the shutter button. Unfortunately, there is 
not much point in implementing that until the low-resolution non-standard JPEG 
format is better understood, because that is what it uses. 

Some things which work for me, with various gphoto2 options:

gphoto2 --summary 
will report the number of low-resolution pictures and the number of 
high-resolution pictures separately, as well as the total number
of pictures. 

gphoto2 -P 
is functional, but see previous remarks about high and low resolution  
photos. 

gphoto2 -p x-y 
is functional, too, assuming there are at least y pictures in the camera 
and x <= y.  

gphoto2 --get-all-raw-data

License: 

LGPL (see the head of the libgphoto2 source tree; this camera library is a 
part of the libgphoto2 project).

Warranty: 

None, neither expressed nor implied. This camera driver has been written 
for the sake of the challenge, and in order to learn more about both hardware 
and software support for the hardware from the actual experience of writing 
a device driver. Those intending to use the Aox camera library should keep 
these facts in mind, in order to keep an appropriate sense of perspective. 

Nevertheless, the Aox camera library driver works for me and carries out for 
me the functions which are described here. I seriously hope and intend that 
it should work for others, too. Please report any problems or bugs to me or 
to the gphoto-devel mailing list. 

Copyright by Theodore Kilgore, November 11, 2003.
kilgota at auburn.edu

Additional remarks, June 27, 2004:

First the good news:
Thumbnail capability has been added, and the library should be fully functional 
now with a GUI frontend. I have tested both gtkam and digikam. Gtkam works very 
nicely for me, but for unknown reasons my digikam somehow fails to display the 
thumbnails. That is probably the fault of my digikam setup, because it fails for 
all of my cameras. It may work for you and if you want to use digikam then 
certainly you should try it. 

The bad news:
The camera has "video clip" capability, meaning that with a certain camera 
setting it is possible to hold down the shutter button and keep shooting 
frames (the only limitation being the amount of free memory in the camera). 
Unfortunately, the clip mode uses the non-standard JPEG compression, and thus 
there is no point in trying to implement clip mode until the compression mode 
is understood.