Re: SPCA1527A/SPCA1528 (micro)SD camera in webcam mode

[Andy Walls <awalls@md.metrocast.net>]

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On Sun, 2010-05-30 at 23:28 +0200, Ondrej Zary wrote:
> On Sunday 30 May 2010 21:26:14 Andy Walls wrote:
> > On Sun, 2010-05-30 at 19:55 +0200, Ondrej Zary wrote:
> > > On Sunday 30 May 2010 13:34:55 Jean-Francois Moine wrote:

> >
> > SP54 is Sunplus' ( http://www.sunplus.com.tw/ ) FourCC code for a
> > version of MJPEG with the headers removed according to
> >
> > 	http://www.fourcc.org/
> >
> > > Maybe we can dump some data, create AVI file from that and try to decode
> > > the file using that codec.
> >
> > FourCC.org points to this page:
> >
> > 	http://libland.fr.st/download.html
> >
> > which points to a utility to conver the data back into an MJPEG:
> >
> > 	http://mxhaard.free.fr/spca50x/Download/sp54convert.tar.gz
> >
> >
> > I have no idea if any of the above is true, 'cause I read it on the
> > Internet. ;)
> 
> Modified that utility to work on raw video frame extracted from usbsnoop file. 
> The bad news is that the resulting jpeg file is not readable.
> 
> I also deleted the sp5x_32.dll file and the camera still works...

I would try extracting a JPEG header from one of the files captured by
the camera in stand alone mode (either a JPEG still or MJPEG file), and
put that header together with the image data from the USB capture.  It
may not look perfect, but hopefully you will get something you
recognize.

Attached was Theodore's first attempt of such a procedure with a header
extracted from a standalone image file from my Jeilin based camera and
USB snoop data from the same camera.  It wasn't perfect, but it was
recognizable.


I did look at the image data file Jean-Francois provided from your
usbsnoop logs.  To my eye the data looks like it is Huffman coded
(indicating JPEG).  Maybe I'm just seeing what I want to see.


Regards,
Andy

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