Re: MPEG player

From: Johan Klockars <rand_at_cd.chalmers.se>
Date: Wed, 10 Dec 1997 14:54:51 +0100 (MET)

> PlayMPEG (the Griff program) - this played OK for me but seemed much
> slower than I remember it from last time. As I have upgraded my
> Falcon (AB then Nemesis) I have made some notes of performance
> figures for comparison. It was much slower than before. I checked

Access to the normal RAM is quite a bit slower from the AB040 than on a
normal Falcon. That includes communication with the DSP, since that's on
the same bus.

> tried again. This time all I got was a black screen but when I

Sounds to me like it's using a screen buffer in the BSS area rather than
allocating one. Unless you didn't force the program to allocate from
FastRAM (another of those flags), that is.
Screen buffers must be in standard RAM or you won't see anything.

> noticed another prog of mine going slower than normal till I changed
> the TT-RAM flags.

Running programs in standard RAM is a _very_ bad idea with the AB040.
FastRAM accesses are about ten times faster.

> I am still puzzled by the black screen on PlayMPEG, perhaps NVDI 4
> isn't quite setup correctly. I could try putting v2 back again.

It would be very surprising if NVDI had anything to do with this. You don't
normally go via the VDI when you want fast screen output.

-- 
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Received on on. des. 10 1997 - 18:15:00 CET

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