From owner-freebsd-multimedia Fri Nov 7 00:45:04 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id AAA19101 for multimedia-outgoing; Fri, 7 Nov 1997 00:45:04 -0800 (PST) (envelope-from owner-freebsd-multimedia) Received: from labinfo.iet.unipi.it (labinfo.iet.unipi.it [131.114.9.5]) by hub.freebsd.org (8.8.7/8.8.7) with SMTP id AAA19080 for ; Fri, 7 Nov 1997 00:44:50 -0800 (PST) (envelope-from luigi@labinfo.iet.unipi.it) Received: from localhost (luigi@localhost) by labinfo.iet.unipi.it (8.6.5/8.6.5) id IAA26304; Fri, 7 Nov 1997 08:32:24 +0100 From: Luigi Rizzo Message-Id: <199711070732.IAA26304@labinfo.iet.unipi.it> Subject: Re: Teletext decoding with the Hauppauge... To: arg@arg1.demon.co.uk (Andrew Gordon) Date: Fri, 7 Nov 1997 08:32:24 +0100 (MET) Cc: multimedia@FreeBSD.ORG In-Reply-To: from "Andrew Gordon" at Nov 6, 97 11:51:44 pm X-Mailer: ELM [version 2.4 PL23] Content-Type: text Sender: owner-freebsd-multimedia@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk > I am currently working on a teletext system (using some rather better > hardware that allows the complete page database to be maintained I don't think there is really a limitation on the hardware (see below) > in RAM/on disk rather than waiting for individual pages). My plan for > user interface is to make a CGI that serves web pages. Yes, this was something we hacked up a few years ago. Unfortunately the code for teletext->gif conversion was a complete mess. My previous approach was to use the video capture part of the Hauppauge (Bt848) to sample the incoming video stream and do all the necessary signal processingand teletext decoding in software. It pretty much works, capturing pages at almost full speed on a PPro200 -- obviously it kills the machine... The code is on my web page if you want: http://www.iet.unipi.it/~luigi/FreeBSD.html Using the embedded teletext decoder on the hauppauge saves quite a few CPU cycles. The SAA5246 can capture up to 8 pages simultaneously, and you can set up filters to select specific pages or get the first one which comes in. So, although a bit tricky, one approach could be to use 2-3 such pages to capture any data which comes in, and the remaining to capture specific pages. The tricky part is to schedule which page to request, avoid problems caused by requests for non-existing pages, etc. I am working on this as well. > Most of what I am doing won't be directly applicable, but I can let > you have a teletext page -> .gif file conversion utility if you want it. yes please... Cheers Luigi