Date: Tue, 18 Apr 2006 10:54:10 +0200 (CEST) From: Oliver Fromme <olli@lurza.secnetix.de> To: freebsd-multimedia@FreeBSD.ORG Subject: Re: ffmpeg question Message-ID: <200604180854.k3I8sAB7049958@lurza.secnetix.de> In-Reply-To: <AEB45AE1-6DDE-4D40-B05B-36CCEB9A7186@netmusician.org>
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Joe Auty <joe@netmusician.org> wrote: > The cat command works perfectly, but I'm trying to script it, and > since you can use ffmpeg to specify how many seconds of footage to > capture I'm trying to make this work. #!/bin/sh - DURATION=20 DATESTAMP=$(date +%Y-%m-%d) cat /dev/whatever > /foo/bar-${DATESTAMP}.mpg & CATPID=$! sleep $DURATION kill $CATPID > According to Quicktime's Get Info, the cat files are mpeg2... Yes. What exactly is wrong with MPEG-2 in your opinion? > I'd like to know the best way to preserve the same quality > from the cat command using ffmpeg. ffmpeg decodes from MPEG format and then re-encodes it, which is lossy, so you can never preserver the same quality. That is, unless you use "copy" for the codec, which means it won't decode/encode anything -- but then it's just like teh cat command anyway, with a hundred times the overhead. > Am I starting to make sense now? I'm not sure. :-) Best regards Oliver -- Oliver Fromme, secnetix GmbH & Co. KG, Marktplatz 29, 85567 Grafing Dienstleistungen mit Schwerpunkt FreeBSD: http://www.secnetix.de/bsd Any opinions expressed in this message may be personal to the author and may not necessarily reflect the opinions of secnetix in any way. "And believe me, as a C++ programmer, I don't hesitate to question the decisions of language designers. After a decent amount of C++ exposure, Python's flaws seem ridiculously small." -- Ville Vainio
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