From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from proofpoint-cluster.metrocast.net ([65.175.128.136]:23379 "EHLO proofpoint-cluster.metrocast.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751745Ab0EaMnm (ORCPT ); Mon, 31 May 2010 08:43:42 -0400 Subject: Re: SPCA1527A/SPCA1528 (micro)SD camera in webcam mode From: Andy Walls To: Jean-Francois Moine Cc: Ondrej Zary , linux-media@vger.kernel.org In-Reply-To: <20100531091953.39055944@tele> References: <201005291909.33593.linux@rainbow-software.org> <201005302328.56690.linux@rainbow-software.org> <1275256691.4863.19.camel@localhost> <201005310003.12761.linux@rainbow-software.org> <20100531091953.39055944@tele> Content-Type: text/plain; charset="UTF-8" Date: Mon, 31 May 2010 08:43:51 -0400 Message-ID: <1275309831.2227.26.camel@localhost> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: On Mon, 2010-05-31 at 09:19 +0200, Jean-Francois Moine wrote: > On Mon, 31 May 2010 00:03:10 +0200 > Ondrej Zary wrote: > > > > 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. > > > > Just thought about the same thing so I uploaded a video file: > > http://www.rainbow-software.org/linux_files/spca1528/sunp0003.avi > > > > > 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 could not believe it! I already tried the image as JPEG, but I got > just big colored pixels. I changed the 'samples Y' from 21 to 22 and > I got something coherent! Here is the same image as yesterday with > JPEG 411 header, compression quality 80% and insertion of 0x00 after > 0xff. Very nice work! I think I understand the 'samples Y' change. According to ITU T.81, you changed the Vertical sampling factor in the Y component. So, I guess Luma is undersampled vertically for that mode of the camera (the camera only really has a 240 line sensor)? Regards, Andy