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Date:      Wed, 3 Dec 1997 00:29:58 +0100 (MEZ)
From:      Robert Eckardt <roberte@MEP.Ruhr-Uni-Bochum.de>
To:        multimedia@freebsd.org
Subject:   fxtv-0.46 to raw device
Message-ID:  <199712022329.AAA26946@ghost.mep.ruhr-uni-bochum.de>

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Hi (Randall ;-)

using a Haupauge video card I tried capturing a minute or so to disk.
(FreeBSD-2.2.2, fxtv-0.46, bt848.971105,
 P133, ASUS TVP4, 64MB, HDs: WD (IDE) and IBM (IDE+SCSI/ncr53c810),
 Hauppauge WinCast/TV, Temic PAL tuner + SoundBlaster 16 Virge PnP)
I used MPEG output mode.

However, the captured sequence has a lot of "hickups".
(several ppm-files are 5- to 48-fold hard links)
(This is with PAL/BDGHI, 25fps, 256x192)
(ideal would be 384x288 @ 25fps)
Even reducing the rate to 15 fps didn't get rid of them.

I tried spreading the raw files over 3 disks yielding only a
small improvement (5- to 11-fold hard links).

Therefore I tried to write to a raw partition (rwd1s2).
But, after "Converting RAW to PPM...", which produced indeed a lot
of ppm-files, the next step "Failed reading raw image file".
(trying to convert sound ?)

Even after looking at the source, I still dont't understand why. ???


Another thing I noticed:
dd bs=4k count=10000 if=/dev/zero of=/dev/rwd1s2  gives me
6307378 bytes/sec, running smoothly.
Using fxtv on that device lets the disk heads scatter (swap ?)
and Optimize only gives 256x192@24fps with no CPU- or disk-intensive
processes running.


Finally, is it planned or is s.o. already working on converting
a RAW-file directly (e.g., a stream of piped commands) to an
MPEG-stream ?
Wouldn't this be the canonical approach on a Unix system ?

It seems that the intermediate steps use much more disk space
then the raw file (ca. 200MB for a min., but my partition with
780MB free runs out of space already for 1 1/2 min.).


TIA,
Robert

-- 
Robert Eckardt                \\ FreeBSD -- solutions for a large universe.(tm)
RobertE@MEP.Ruhr-Uni-Bochum.de \\       What do you want to boot tomorrow ?(tm)
http://WWW.MEP.Ruhr-Uni-Bochum.de/~roberte
For PGP-key finger roberte@gluon.MEP.Ruhr-Uni-Bochum.de



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