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 m1QGuTpD022786 for ; Tue, 26 Feb 2008 11:56:29 -0500 Received: from mail.mediaxim.be (dns.adview.be [193.74.142.132]) by mx3.redhat.com (8.13.8/8.13.8) with ESMTP id m1QGtwTi001298 for ; Tue, 26 Feb 2008 11:55:58 -0500 Received: from localhost (mail.mediaxim.be [127.0.0.1]) by mail.mediaxim.be (MediaXim Mail Daemon) with ESMTP id CE9D734025 for ; Tue, 26 Feb 2008 17:55:54 +0100 (CET) Received: from [10.32.13.124] (unknown [10.32.13.124]) by mail.mediaxim.be (MediaXim Mail Daemon) with ESMTP id 71F6434022 for ; Tue, 26 Feb 2008 17:55:53 +0100 (CET) Message-ID: <47C44499.7050506@mediaxim.be> Date: Tue, 26 Feb 2008 17:55:53 +0100 From: Michel Bardiaux MIME-Version: 1.0 To: video4linux-list@redhat.com References: <47C3F5CB.1010707@mediaxim.be> <20080226130200.GA215@daniel.bse> In-Reply-To: <20080226130200.GA215@daniel.bse> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit Subject: Re: Grabbing 4:3 and 16:9 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: Daniel Glöckner wrote: > On Tue, Feb 26, 2008 at 12:19:39PM +0100, Michel Bardiaux wrote: >> Here in Belgium the broadcasts is sometimes 4:3, sometimes 16:9. >> Currently, the card goes automatically in letterbox mode when it >> receives 16:9, and our software captures the 4:3 frames at size 704x576. > > The card does not go into letterbox mode. It's the broadcaster who > squeezes the 16:9 picture into 432 lines surrounded by 144 black lines. Let me rephrase to check I understood correctly. In analog TV, there are no anamorphic broadcasts. When the WSS (accessible via /dev/vbi, right?) states 16:9, then a 16:9 (sic) TV switches to a mode where it crops 2x72 lines, then stretches the image both horizontally and vertically to fill the whole 16:9 screen. Am I correct? I must admit I have difficulty believing that. Could you give me the URLs of sites explaining all that? > Some fill the chroma part of the black lines with a PALPlus helper > signal. Although the algorithms to decode PALPlus are well documented in > ETS 300 731, I have never seen a software implementation. > >> 1. How do I sense from the software that the mode is currently 16:9 or 4:3? > > Some broadcasters use WSS to signal 16:9. > In Germany some signal 4:3 even on 16:9 shows. > Read ETSI EN 300 294. > >> 2. How do I setup the bttv so that it does variable anamorphosis instead >> of letterboxing? If that is at all possible of course... > > You can't. Bttv can't stretch vertically. > > Daniel -- Michel Bardiaux R&D Director T +32 [0] 2 790 29 41 F +32 [0] 2 790 29 02 E mailto:mbardiaux@mediaxim.be Mediaxim NV/SA Vorstlaan 191 Boulevard du Souverain Brussel 1160 Bruxelles http://www.mediaxim.com/ -- video4linux-list mailing list Unsubscribe mailto:video4linux-list-request@redhat.com?subject=unsubscribe https://www.redhat.com/mailman/listinfo/video4linux-list