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Date:      Wed, 17 May 2000 14:30:57 +0200 (CEST)
From:      Oliver Fromme <olli@dorifer.heim3.tu-clausthal.de>
To:        freebsd-multimedia@FreeBSD.ORG
Subject:   Re: video recording and encoding on FreeBSD
Message-ID:  <200005171230.OAA59142@dorifer.heim3.tu-clausthal.de>
In-Reply-To: <8ftopj$44s$1@atlantis.rz.tu-clausthal.de>

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In list.freebsd-multimedia Stefan `Sec` Zehl <sec@42.org> wrote:
 > I'm thinking about transfering some videos from my VCR to my computer.
 > Now I wonder if this is feasible at all. Are there any (free/cheap)
 > encoders around to compress this huge amount of data into some commonly
 > used data-format (like mp2/mov/realvideo). And, which cards are
 > supported for digitising video data?

If you want good quality and good compression and you don't
have _lots_ of diskspace, then you'd have to use a hardware
realtime MPEG encoder.  These are not exactly cheap, and you
cannot use them in FreeBSD, I'm afraid.  (If I'm wrong, please
someone let me know...)

A single uncompressed (full) frame at VHS resolution (PAL) is
roughly 1/3 Mbyte.  Those are coming at a rate of 25 per
second, so you get 8 Mbyte/s.  This is not including audio, of
course.  Even when you do YCC-conversion and 1:2:2 downsampling
of the C components (which can easily be done in software)
that's still about 4 Mbyte/s.  For a 4h VHS tape that would be
60 Gbyte.  Well, some cheap big IDE drives could hold it, but
you have to make sure that they're "AV certified", i.e. that
they're guaranteed to provide uninterrupted sequential
performace without rekalibration pauses or things like that.

Once you have the uncompressed video on disk, you can use a
software MPEG encoder.  There are several to choose from; look
at the ports collection.  It probably needs some experimenting.

Regarding the compression format:  I'd recommend MPEG-1 with
similar parameters as used on VideoCDs.  MPEG is an "open",
non-proprietary format, and there's software for almost every
OS on the planet.  Another advantage is the fact that you can
put the MPEG file on a CD-R (using VideoCD-capable mastering
software) and then play it on any standard DVD player (or any
VideoCD player, of course, but those are getting rare).

Regards
   Oliver

-- 
Oliver Fromme, Leibnizstr. 18/61, 38678 Clausthal, Germany
(Info: finger userinfo:olli@dorifer.heim3.tu-clausthal.de)

"In jedem Stück Kohle wartet ein Diamant auf seine Geburt"
                                         (Terry Pratchett)


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