From owner-freebsd-multimedia Mon Apr 29 06:52:41 1996 Return-Path: owner-multimedia Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id GAA16660 for multimedia-outgoing; Mon, 29 Apr 1996 06:52:41 -0700 (PDT) Received: from mail.barrnet.net (mail.barrnet.net [131.119.246.7]) by freefall.freebsd.org (8.7.3/8.7.3) with ESMTP id GAA16654 for ; Mon, 29 Apr 1996 06:52:39 -0700 (PDT) Received: from labinfo.iet.unipi.it (labinfo.iet.unipi.it [131.114.9.5]) by mail.barrnet.net (8.7.5/MAIL-RELAY-LEN) with SMTP id GAA22840 for ; Mon, 29 Apr 1996 06:51:47 -0700 (PDT) Received: from localhost (luigi@localhost) by labinfo.iet.unipi.it (8.6.5/8.6.5) id OAA05351 for multimedia@freebsd.org; Mon, 29 Apr 1996 14:42:58 +0200 From: Luigi Rizzo Message-Id: <199604291242.OAA05351@labinfo.iet.unipi.it> Subject: About video compression etc. To: multimedia@freebsd.org Date: Mon, 29 Apr 1996 14:42:58 +0200 (MET DST) X-Mailer: ELM [version 2.4 PL23] Content-Type: text Sender: owner-multimedia@freebsd.org X-Loop: FreeBSD.org Precedence: bulk Have a question on video compression, with particular reference to live video compression. I have looked at encoding algorithm used by nv, but suspect the same applies to h.261, mpeg etc. When selecting which blocks to send to the network, nv compares the current with the previous image. If the difference exceeds a (fixed) threshold, then the block is scheduled to be sent. Apart from the obvious change of making the threshold dependant on the actual bandwidth on the connection, is there any algorithm which also sorts blocks depending on the amount of change from the previous one ? This might give a better visual effect. Cheers Luigi ==================================================================== Luigi Rizzo Dip. di Ingegneria dell'Informazione email: luigi@iet.unipi.it Universita' di Pisa tel: +39-50-568533 via Diotisalvi 2, 56126 PISA (Italy) fax: +39-50-568522 http://www.iet.unipi.it/~luigi/ ====================================================================