[geeks] Ok I am ready to kill this Fu**ing linux box

[Joshua D Boyd]

On Mon, May 27, 2002 at 09:12:48PM -0700, Peter L. Wargo wrote:
> On Monday, May 27, 2002, at 09:02 , Joshua D Boyd wrote:
> 
> >I have one of those cards, but I think it is bad, since I couldn't get
> >3 different AV Macs (840av, 8100av, 7100av) to recognize it.  I have
> >a few questions.  First, how do you convert the video to something that
> >can be played back on machines without the card?  I know that premiere 
> >can
> >do that, but I was hoping some free utility also could.
> 
> Did you install the software for it?  After that, you just use a 
> video-capture app. (I use fusion recorder) The output is a quicktime 
> movie.

I copied the extension to the extension folder, uninstalled quicktime, then
installed the version on the floppy, then tried... Ger, the Mac isn't handy
to check what program I tried to run.  It was one of the ones on the diskette
though, not fusion recorder.  It reported that the extension wasn't loaded.
I'll have to try again so I can report the exact error.

> Not too bad.

Hmm.  Now if only I knew what your standard of not too bad was.
 
> I dunno if the 840AV's internal scsi can keep up with uncompressed 
> video.  With the spigotAV, I gor 640x480 at 30fps (compressed), but I 
> couldn't watch it while capturing, just listen.  REsults are good, I was 
> able to then use quicktime pro on the G4 to edit  it and then toast to 
> make a VCD.

The real question isn't whether the internal SCSI can handle it (since it
can't).  The real question is can the bus handle it?  A pair of striped
fast wide scsi2 cards (either Jackhammers or ATTO cards), using software 
striping, would be required, unless there happens to be some UltraWide 
controllers that I've never heard of. 

To pull of that trick would require moving 27megs per seconds to ram (don't
know if DMA is supported by the NuVista or Targa2k, but I'd hope it would
be).  Then that data needs to be read out to the scsi controllers.  That is
the minumum bus load.  I don't know what the protocol overhead is, nor what
amount the CPU would need to do to handle the striping.  Now, my understanding
is that on a Quadra840AV, Nubus is 32bits wide and 40mhz, which is 
theoretically enough.  32bits at 20mhz is even more than enough.

Anyway, Low End Mac reports that an 840av w/ 2 FWB Jackhammer cards in 1995
was capable of streaming 34megs per second to the screen memory.  If that
is true, then why can't I just use the built in digitizer for uncompressed
capture?  I know the digitizer does it since it allows uncompressed capture
to memory.

Frankly, I suspect most of the "limitations" of the machine are just imposed
by shortsighted programmers.  It seems to me that for low end work, I 
shouldn't need a SPAV or VideoVision or Targa2k, I should only need a pair
of scsi cards, and for highend (meaning pro level component work), the
same scsi cards, plus either a NuVista or a Targa2kPro.  But most people
make it sound like even if the machine can do it (which they don't want to
confirm), I'd have to bypass the drivers to do it due to limitations built
in around the affordable harddrives of the day.  

I could be wrong though, and don't really want to sink the cost of two
SCSI cards (probably a little over $100), and all those programming hours
(which I'm not entirely sure I'm good enough for) to find I'm wrong.

-- 
Joshua D. Boyd