From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx3.redhat.com (mx3.redhat.com [172.16.48.32]) by int-mx1.corp.redhat.com (8.13.1/8.13.1) with ESMTP id m7LHFxHP023681 for ; Thu, 21 Aug 2008 13:15:59 -0400 Received: from smtp7-g19.free.fr (smtp7-g19.free.fr [212.27.42.64]) by mx3.redhat.com (8.13.8/8.13.8) with ESMTP id m7LHFnqg002046 for ; Thu, 21 Aug 2008 13:15:49 -0400 From: Jean-Francois Moine To: Hans de Goede In-Reply-To: <48AD72D5.4050408@hhs.nl> References: <48A8698E.3090004@hhs.nl> <1219304978.1762.25.camel@localhost> <48AD72D5.4050408@hhs.nl> Content-Type: text/plain; charset=ISO-8859-1 Date: Thu, 21 Aug 2008 18:58:57 +0200 Message-Id: <1219337937.1726.39.camel@localhost> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Cc: Linux and Kernel Video Subject: Re: PATCH: gspca-spc200nc-upside-down-v2 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: video4linux-list-bounces@redhat.com Errors-To: video4linux-list-bounces@redhat.com List-ID: On Thu, 2008-08-21 at 15:51 +0200, Hans de Goede wrote: > Jean-Francois Moine wrote: [snip] > > Well, I looked at various messages in various mail-lists talking about > > upside down. Sometimes, a webcam may be normal or upside down, or even > > just mirrored. Two times only (Vimicro 0325 and 0326), they say that the > > webcam is always upside down. So, is it useful to make a generic code > > for this specific case? > > Yes, as that will make these webcam work out of the box for end users. Please > stop thinking as a developer for a moment and start thinking as a simple end > user plugging such a cam into his asus eee pc, which is his first and only > linux machine. What do you think he will like better, the upside down picture > or the hey cool I plug in in this cam and it just works (tm) ? It is possible if some system application (hal?) does the job. > > For the general case (the webcam may have H or V flip, or both - upside > > down). The user will see it. If she may use the HFLIP and VFLIP > > controls, she will get a correct image. > > Currently the 4 major (as in more then just a gimmick) end user v4l wewbcam > programs I'm aware of are: > ekiga > cheese > flash plugin > skype > > And AFAIK (didn't check skype) non of these offer a simple GUI option for the > user to change vflip / hflip controls. Telling a user to go the cmdline is not > *userfriendly* and in this scenario is not necessary! You did not try v4l2ucp? [snip] > The reason why I'm spending tons of time on all this webcam stuff, is so that > end users can just plugin their cam and have it work. If that requires a > special flag for just these 2 cams so be it and I strongly believe we will > encounter other cams like this in the future. [snip] Sorry, but I am not happy the way it is done. Here is an other proposal. In the V4L2 spec, VIDIOC_QUERYCTRL returns the controls accepted (or rejected) by the driver, and also information about these ones. As the Vimicro/Z-star has no way to change H and V flips, the driver may give these controls as READ_ONLY and set the control values according to the device type. Now, when accessing the device, the V4L library will get the flags and values of the H and V flip. If HFLIP and VFLIP are settable, the driver does all the job. If not (HFLIP and VFLIP are READ_ONLY or INVAL), the library memorizes the control values of the driver (INVAL implies 0) and also the values asked by the application. Frame decoding is then H and/or H flipped according to ( ^ ). And now, for something completely different! I could not find a MS-win snoop of these 'upside down' devices (0471:0325 and 0471:0326). I want to check the initialization sequences and also the format of the frames. May anybody send one to me? Thank you. Cheers. -- Ken ar c'hentań | ** Breizh ha Linux atav! ** Jef | http://moinejf.free.fr/ -- video4linux-list mailing list Unsubscribe mailto:video4linux-list-request@redhat.com?subject=unsubscribe https://www.redhat.com/mailman/listinfo/video4linux-list