Date: Wed, 05 Mar 1997 23:02:25 -0800 From: Amancio Hasty <hasty@rah.star-gate.com> To: Luigi Rizzo <luigi@labinfo.iet.unipi.it> Cc: tom@inna.net, smp@csn.net, jamie@inna.net, multimedia@freebsd.org Subject: Re: Video Capture for FreeBSD Message-ID: <199703060702.XAA01157@rah.star-gate.com> In-Reply-To: Your message of "Thu, 06 Mar 1997 07:05:48 %2B0100." <199703060605.HAA15873@labinfo.iet.unipi.it>
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Hmmm...
I wonder if the the filesystem which he is writing to is nfs mounted?
Amancio
>From The Desk Of Luigi Rizzo :
> > Try compiling rgb16 as:
> >
> > cc -o rgb16 -m486 -O2 rgb.c
>
> nope, the trick is buffering data before writing:
>
> > > for (c = 0 ; c < ROWS*COLS; c++) {
> > > b[0]= ((*rgb16 >> 7) & 0xf8); /* r */
> > > b[1]= ((*rgb16 >> 2) & 0xf8); /* g */
> > > b[2]= ((*rgb16++ << 3) & 0xf8); /* b */
> > > write(o, &b[0], 3);
>
> this one issues a system call for each pixel (3 bytes of output!).
>
> 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/
> _____________________________|______________________________________
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