From owner-freebsd-multimedia@FreeBSD.ORG Thu Feb 19 17:47:51 2004 Return-Path: Delivered-To: freebsd-multimedia@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 1FE8116A4CE for ; Thu, 19 Feb 2004 17:47:51 -0800 (PST) Received: from arg1.demon.co.uk (arg1.demon.co.uk [62.49.12.213]) by mx1.FreeBSD.org (Postfix) with ESMTP id C594D43D1F for ; Thu, 19 Feb 2004 17:47:50 -0800 (PST) (envelope-from arg-bsd@arg.me.uk) Received: by arg1.demon.co.uk (Postfix, from userid 1002) id 9F1259B1B; Fri, 20 Feb 2004 01:47:49 +0000 (GMT) Received: from localhost (localhost [127.0.0.1]) by arg1.demon.co.uk (Postfix) with ESMTP id 9AF475DB3; Fri, 20 Feb 2004 01:47:49 +0000 (GMT) Date: Fri, 20 Feb 2004 01:47:49 +0000 (GMT) From: Andrew Gordon X-X-Sender: freebsd@server.arg.sj.co.uk To: Torfinn Ingolfsen In-Reply-To: <20040219235527.52d232f6.torfinn.ingolfsen@broadpark.no> Message-ID: <20040220012318.Q3149@server.arg.sj.co.uk> References: <20040219005421.141380e0.torfinn.ingolfsen@broadpark.no> <20040219235527.52d232f6.torfinn.ingolfsen@broadpark.no> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII cc: freebsd-multimedia@freebsd.org Subject: Re: Intel 845 and TV-out: how to switch to PAL mode? X-BeenThere: freebsd-multimedia@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Multimedia discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 20 Feb 2004 01:47:51 -0000 On Thu, 19 Feb 2004, Torfinn Ingolfsen wrote: > > Yes, i am aware of that. My (old) TV only has composite and SCART input > (and RF / antenna of course). I have tried the following combinations: > 1) s-video out from pc, via an s-video to composite adapter, to > composite input on TV. > 2) s-video out from pc, via a s-video to SCART adapter, to SCART input > on TV. > 3) composite out from pc, to composite input on TV. > > All combinations result in a b/w picture, both in console and in X. I know nothing about the Intel 845, but can offer a few hints about S-video and SCART connectors: - S-video provides two video signals: 'Y' and 'C'. The Y signal is the luminance and syncs, so is equivalent to a composite video signal for a b/w picture. The 'C' signal carries the colour sub-carrier. - It would theoretically be possible to build a passive converter to make composite from S-video (by adding the two signals together with a couple of resistors), though I've never seen one, and it wouldn't work wonderfully well. However, I HAVE seen a converter (supplied with Hauppauge PCI cards) which adapts a single RCA-phono connector for composite into an S-video connector. This is purely a mechanical adaptor, connecting to the 'Y' terminals on the S-video connector, and assumes that you have configured the card appropriately. This type of converter does not do any kind of signal conversion. - SCART connectors provide 4 video input signals to the TV. In normal use, these are composite plus R,G,B. When using RGB, the composite signal is still present and used to provide syncs. The TV will normally switch automatically between composite and RGB under control of another signal ('fast blanking'). SCART connectors can also be used (with some TVs only) for S-video. SCART to S-video adaptors are purely mechanical adaptors which have no effect on the signals. In this case, the 'Y' signal is fed on the composite pin on the SCART connector, and 'C' on the red pin. There is nothing on the connector itself to switch into S-video mode: it can only be used if the TV has been manually configured to do S-video rather than RGB. Many TVs don't accept S-video at all. - You should be able to tell the difference between a b/w picture due to wrong PAL/NTSC/SECAM selection and a b/w picture due to connecting an S-video output to a composite input. Look at a picture with some areas of solid colour. If it's an S-video 'Y' signal, the vertical edges of coloured areas will be just as sharp as the edges of black/white areas. If it's a composite signal of the wrong type for the TV, the edges of coloured areas should be noticeably fuzzy compared to white areas which will be sharp. You may also be able to see a 'grainy' appearance to areas that should be coloured which is not visible in areas which are supposed to be grey.