/* README for libgphoto2/camlibs/sonix camera library
 *
 * Copyright (C) 2005 Theodore Kilgore <kilgota@auburn.edu>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA  02110-1301  USA
 */

This library supports fully the still-camera functions of several cameras
which use the sn9c2028 chip from Sonix (Vendor ID 0x0c45).


Differences in the functions and features of the known cameras can be
distinguished through the USB Product number, and also by a four-digit
hexadecimal string passed by the camera during initialization -- apparently a
firmware version number and/or an identification number for the video sensor.
If you have a Sonix sn9c2028 camera which returns a number not listed in
sonix.c, then your camera may or may not work with this code. How would I know?
Please inform if you get a different ID number!

Here we give a brief description both of currently-supported cameras and of the
supported gphoto2 functions for each.


Vivicam 3350b:

Uses an OV7630 sensor. Produces a maximum resolution of 640x480 and an option
to use 320x240. The photos are all compressed. The compression scheme is
lossy. The decompression algorithm originates, I understand, in the work of
Bertrik Sikkens for the sn9c102 cameras. In the macam project for MacOS-X
camera support(webcam-osx project on Sourceforge), the decompression algorithm
for the sn9c2028 cameras was developed by Mattias Krauss and adapted for use
with the Vivitar Vivicam 3350B in particular by Harald Ruda
<hrx at users.sourceforge.net>. Harald brought to my attention the work already
done in the macam project, pointed out that it is GPL code, and invited me to
have a look. Thanks, Harald. The decompression algorithm used here is similar
to what is used in the macam driver, but is considerably streamlined and
improved. It seems to work perfectly. Brightness and/or gamma do sometimes
need to be adjusted with a photo editor such as Gimp, ImageMagick, or xv,
especially for photos taken in dim light.

Features of the camera include the ability to delete all photos. The "delete
last" function and the "capture-image" function, which will work for some
other Sonix sn9c2028 cameras and are thus supported in this library, do not
seem to work with the my Vivicam 3350B and are therefore disabled for this
camera. These cameras can all shoot "movie clips" which are saved as AVI files.
Webcam functionality uses isochronous transfer; thus it lies outside the scope
of libgphoto2 and is therefore not supported here.


DC31VC:

Yet another camera which the macam driver also supports has been listed here
as a supported camera. It apparently uses 352x288 and 176x144 resolution
settings. I know of it only second hand, have not personally tested it, and
would appreciate any reports about it (I suspect it is similar to the Sakar
Digital Keychain camera).


Sakar Digital Keychain #11199:

This camera does not use data compression. It will hold 18 photos at
352x288 resolution, and 70 photos (or a clip containing at most 70 frames)
at 176x144 resolution, or any combination of these which does not fill up the
camera. Clips are processed as AVI files.

This camera also supports gphoto2 --capture-image, which will cause a photo
to be taken and stored among the photos on the camera for later download (the
capture dimensions are always 352x288).

The photo which one has just shot can of course be downloaded immediately
using gphoto2 -p (its number, which will be the last taken) and, if desired,
can be deleted immediately afterwards using gphoto2 -d (its number) which
this camera also permits (unlike the Vivicam 3350b).

Mini-Shotz ms350:

This camera has 640x480 and 320x240 resolution settings. Its features are
otherwise quite similar to those of the Sakar Digital Keychain #11199, except
that it exclusively uses the compressed mode.

Genius Smart 300:

This camera has 640x480 and 320x240 resolution settings. Its features are
otherwise quite similar to those of the Sakar Digital Keychain #11199 and the
Mini-Shotz ms350, except that it uses compressed mode for multiframe shooting,
but offers both compressed and uncompressed modes as options for still photos.
It does not support gphoto2 --capture-image. It does support deletion of
the last entry on the camera.

GUI frontends:

Libgphoto2 , of course, permits the use of a GUI frontend as well as the
gphoto2 command-line utility. I have tested my two cameras with gtkam and with
flphoto. Both of them work, with the following provisos:

-- There is an unresolved problem with gtkam, when the Sakar Digital Keychain
camera is hooked up and gtkam is started. The LED display starts to move
immediately and keeps on. The LED activity does not stop when gtkam is exited,
but only on camera disconnect from the computer. This phenomenon may be quite
harmless, but who knows? It obviously means that some kind of background
activity is taking place inside the camera. This LED activity does not occur
if the gphoto2 command line or the gphoto2 shell or flphoto are used.
(UPDATE: A workaround patch has been applied, which seems to fix this, as of
08/17/06)


-- flphoto will give a message when asked to save an AVI file, that it cannot
put the AVI file into an "album." Well, perhaps not. But not to worry.
It will save the AVI file anyway, even while protesting.


(Most recent revision of this file is on  12/18/2007)