Re: Apple II Music Video - Welcome to the Jungle!!

["BLuRry" <brendan.robert@gmail.com>]

Frank M. wrote:
> Continuing my previous experiments with rasterizing video on an //e,
> I've finished rendering all 6,462 frames for the music video to Guns N
> Roses "Welcome to the Jungle". Each frame is a single lo-res GR screen
> dump. Obviously this only will work on a machine with a CompactFlash
> drive or in an emulator.

Very cool -- and something I never would have expected out of a //e.
But here's some suggestions that can speed it up.

1) Don't use + in the print statements, use the ; operator
2) Don't convert the loop variable to a string or use an if statement
to zero-pad it.  Just split that part off to a couple of extra loops
3) Break each directory into a separate loop and change the prefix
in-between the loops.  You're causing a lot of extra conditional logic
to be processed.  If you never noticed, applesoft basic is slow. ;-)

If you follow these three recommendations, you'll see it run really
fast for the first few frames and then slow down after about 50 or so
frames.  Ultimately, you'll need to break up the directory structure a
lot more -- or figure out some other way to reduce the number of
entries in the directory (is it slower to read from a non-zero location
starting point of a file?  if so, how much slower?)  Another
possibility is to pre-cache frames into a ram card and use the mem copy
to move over pages as needed during the VBL.  Using this you could load
chunks of frames at a go (probably a lot faster) and avoid having to
hit the filesystem as much.

Apart from that, because you're using a very palette-reduced rendition
of a live motion video it gets very grainy because it's downright
impossible to find good approximate color matches.  If you convert
something that uses a simpler color palette and line art like a cartoon
it will be easier to make things out.  If you wanted a real statement
of irony, I'd recommend "futurama" -- especially the episode where they
reveal Bender's brain is a 6502.  ;-)  But that's just my personal
taste.