[gphoto-devel] Subject: Re: the Wal-Mart Kidz-Cam

[<ki...@ba...>]

To: Martin Laberge <ml...@vi...>
Cc: gph...@li...
Message-ID: <200...@su...>
Content-Type: text/plain; charset=us-ascii

On Mon, Nov 26, 2007 at 02:10:17PM -0500, Martin Laberge wrote:
> I Just had a Wal-Mart- Kidz-Cam with the following chips
> (I opened the case, and looked with a lens)
>
> JL-2005B V4 + OV6650
>
> USB ID is 0979:0227    (the same as the Argus DC1512e)
>
> I just got the SVN trunk and tried it with the same ID
> (as a DC1512e 0979:0227 ) and it do not work. (in jl2005c)
>
> (it is present only in trunk at this time,
>  no official version includes it)


Hi,

I guess I am the person more or less responsible for the jl2005a and 
jl2005c libraries.

My first comment is, that yet another "manufacturer" has switched the 
electronics in a camera without changing the exterior, the brand name, 
or the model name. The "Kidz-Cam" used to answer to 0x2770:0x9120 and had 
in it an SQ905 chip! Oh well, not the first time this happens, and at 
least there is a reason behind the switch, that the SQ905 is discontinued.

Second:

The jl2005a and jl2005c chips are quite different, and I have not yet 
encountered any jl2005b chips, though I am aware that they exist. Some 
details follow.


The jl2005a is pretty much supported, except for one minor, remaining 
issue. My camera works perfectly, but there is someone down in Buenos 
Aires who has another one of these which uses "compression." That 
"compression" is very primitive, in that it simply involves throwing out 
half of the horizontal lines in the image to cut the amount of data by 
50%. Thus, the "decompression" as a consequence will have to consist of 
guessing at the missing lines. I finally got some raw output last night to 
work with, from Buenos Aires, and it seems not to be so terribly difficult 
to do something with it.

The jl2005c is a very different story. I know of two such cameras, so far. 
One of them is the Argus DC-1512E (I have one of them, for all the good it 
does) and someone in Canada owns another. Since he could not provide any 
accurate description of the camera by make, model, and what is on the 
outside of the shrink-wrapped package it came in, the camera does not have 
a separate listing in camlibs/jl2005c/library.c. The camera that I have 
and the one in Canada, too, are using a particularly nasty compressed 
format, and I have absolutely no clue about how it works. The gentleman in 
Canada who owns the camera there is a retired IT person, 73 years old, 
who knows a bit about assembly code. He was all gung-ho about 
disassembling the compression algorithm (I explained that I cannot do 
that, at the same time that I am writing the Linux support, because it 
violates "clean room" principles) but it seems that he has given up, at 
least for now, due to the complexity of the problem. So there we are. 
Anyone else want to have a go at it?

As I said, I have never seen a jl2005b. If that is what you really have, 
then it might be interesting to know what is happening with it.

Theodore Kilgore