1 JEILIN JL2005A STILLCAM DRIVER
2 Copyright Theodore Kilgore <kilgota@auburn.edu> September 16, 2007.
4 (Everything in libgphoto2/camlibs/jl2005a is LGPL-licensed, including this
5 README. See any of the source files for a more complete statement of the
10 This driver is intended to support cameras containing the JL2005A chip from
11 Jeilin Technologies. The interface is proprietary, and these cameras are
12 supported commercially only in Windows. Jeilin Technologies also manufactures
13 chips which go into mass storage cameras. Those cameras can be accessed
14 directly using mass storage support. The company also manufactures some other
15 chips with proprietary interface, but with very different protocols. Some of
16 the cameras may be supported in the future in libgphoto2. The USB Vendor and
17 Product number for the JL2005A cameras is 0x0979:0x0224. At least, I do not
18 know at this time about any other USB id for these cameras, and I also am not
19 aware of any other JL2005A cameras which have different functionality from
22 RECOMMENDATIONS FOR REPORTING CAMERAS
24 Right now, I only own one of these for testing. It is the so-called American
25 Idol keychain camera, which I found at a local KB Toys. I am aware that several
26 others exist. If people will be so kind as to send me the needed details I
27 would be happy to add them explicitly to the list in library.c. Please
28 understand that I need to have whatever information you can find, so please do
29 not throw away the manual, the driver CD, or the plastic package the camera
30 was sold in until we get this information! It happens quite often that the
31 camera itself has no name at all, or just some embossed letters on the plastic
32 which say "DIGITAL CAMERA" -- hardly a unique identifier.
34 Quite often, the only way to identify uniquely an entry-level consumer digital
35 camera is by something appearing in fine print on the packing materials, which,
36 alas, the purchaser can easily overlook and may have simply thrown in the
37 trash. The computer, of course, uses the Vendor:Product ID, but that is of
38 course never printed on the outside of packages. The point is, others should
39 be able to find the camera in the store by the name and description which is
40 given to it in libgphoto2, and moreover it is quite inappropriate if we add
41 support for some dozens of distinct devices, each of which has the name string
42 calling it "DIGITAL CAMERA".
45 WHAT DOES THIS CAMERA LIBRARY CURRENTLY DO?
47 There is support for all of the basic gphoto2 still camera operations which
48 my JL2005A camera is known to support through hardware. This includes support
49 for downloading photos in each of the two available resolution sizes 352*288
50 and 176*144. The data in neither case is compressed, though the raw data for
51 176*144 size is obfuscated and thus not in a completely standard format. Both
52 of these formats are supported in the driver.
54 Support for the option gphoto2 -p (for downloading selected photos or frames)
55 seems to work "out of the box" unlike what happens with some other low-priced
56 cameras. Thus, it ought not to be a problem to use one of these cameras with
57 any of the GUI frontends which are based upon libgphoto2.
59 The camera will not shoot snapshots, neither for immediate download (gphoto2
60 --capture-preview option nor to be stored on the camera for later downloading
61 (--capture-image option). These operations can be done but are implemented
62 through the pccam or webcam interface, which uses isochronous data transmission
63 and is therefore outside the boundaries of the stillcam operations which
66 The camera also does not support the deletion of individual photos, even with
67 a button press, but only the deletion of all. It does seem that to put the
68 camera into pccam mode will delete all photos, but it is not clear at which
69 stage in that process the photos get deleted. Pccam mode involves a different
70 altsetting, which would involve a reset, and then the isochronous inep must
71 be accessed. As my impression by watching the camera being put into pccam mode
72 while photos are already in it is that said photos do not get deleted until
73 the camera actually starts sending data, I have made no attempt at this time
74 to try to use the pccam function to delete all photos.
76 The camera will shoot clips in "continuous" mode, meaning it will shoot frames
77 until the camera is full. The resolution setting for these frames is whatever
78 was the resolution setting before one started to shoot frames. Moreover, this
79 function will not delete any previous photos already in the camera. The
80 resulting frames are downloaded and treated as ordinary photos. If you want to
81 use this function, then, and get an animation, that can easily be done using
82 the "animate" function from the ImageMagick toolkit, or with a similar tool
83 from a similar image processing suite.
85 ANOTHER JL2005A CAMERA, WHICH IN ADDITION TO THE ABOVE, USES COMPRESSION
87 has been discovered by Jeronimo Barraco <jerobarraco@yahoo.com.ar>. That
88 camera is the TDC-15, sold by NogaNet in Argentina. The compressed mode is
89 optional on this camera; one is not forced to use it. On closer investigation,
90 the compression is not actual compression at all, but data truncation. What has
91 been done is that every four lines of data have been "compressed" to two lines.
92 by the simple expedient of suppressing two of them. The same photo still comes
93 out if nothing at all is done to it, but the vertical dimension is divided by
94 two. As an inevitable result, the "decompression" is necessarily some kind of
95 interpolation of the missing lines of data. I have used simple linear
96 interpolation. If someone comes up with a better way which gives nicer-looking
97 images from these cameras, then please let me know. Actually, from the samples
98 which I have on hand the results do not look too bad most of the time. However,
99 the user is advised that occasional raggedness is inevitable from data which
100 has been thus truncated.
102 Another camera which seems to be functionally similar to the TDC-15 is the
103 Cobra DC-125, reported by Tim Johnson <tim@johnsons-web.com>.
108 Absolutely none. Remember, I did not sell you this software. I have written
109 this driver for my own edification and in the sincere hope that it might help
110 you to use of your camera. Please see also the warranty clauses
113 Updated 12/02/2007, 02/21/2009