From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from smtp0.lie-comtel.li ([217.173.238.80]:52282 "EHLO smtp0.lie-comtel.li" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751340AbZBRM6E (ORCPT ); Wed, 18 Feb 2009 07:58:04 -0500 Message-ID: <499C05D8.10303@kaiser-linux.li> Date: Wed, 18 Feb 2009 13:58:00 +0100 From: Thomas Kaiser MIME-Version: 1.0 To: Jean-Francois Moine CC: linux-media@vger.kernel.org Subject: Re: MR97310A and other image formats References: <20090217200928.1ae74819@free.fr> <499B1180.6020600@kaiser-linux.li> <20090218102553.608e026c@free.fr> In-Reply-To: <20090218102553.608e026c@free.fr> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: Jean-Francois Moine wrote: > On Tue, 17 Feb 2009 20:35:28 +0100 > Thomas Kaiser wrote: >> Jean-Francois Moine wrote: >>> BTW, I am coding the subdriver of a new webcam, and I could not find >>> how to decompress the images. It tried many decompression functions, >>> those from the v4l library and most from libgphoto2 without any >>> success. Does anyone know how to find the compression algorithm? >> Hello Jean-Francois >> >> Do you have some more information about the cam and the stream? >> Do you know the frame header? >> Any idea what the compression should be? >> Can you provide a raw stream from the cam? > > Hello Thomas, > > The cam is a Tascorp 17a1:0118. I have USB traces. Starting the webcam > is easy, and so is extracting the images (0x02 + 0xa0/0xa1 at start of > image packets and 0x5a + 0xa5 for end of image with average luminosity). > > I attach an image I extracted by hand from the trace, removing the 2 > bytes of the packets. If it can help, I may send you the whole USB trace > (3 Mb) and/or other images. > > Cheers. > Hello Jean-Francois Thanks, for the frame (or frames?). What resolution did you use while recording this stream? Can you put your USB trace somewhere on the net where I can download it? When I was guessing the streams of webcams, I used to get the sensor into saturation -> complete white picture. So you know how the decoded picture should look like ;-) Actually, it is quite easy to get a webcam sensor into saturation. Just remove the lens of the cam an put a light in front of it. Check in Windoz if the picture is really complete white and then record a stream in Linux. Now, you should get a very homogeneous stream. Look at it and .... I hope you got the idea? Thomas