Re: Full motion video demo - ready to check out

["Frank M." <frank_o_rama@hotmail.com>]

Hey Craig.
The Billy Idol DSK is only 34 frames. it all loads into memory and then
the ML program does what you mentioned. it just swaps successive banks
into the screen memory. the 'play-nodelay' program you mention was just
a test i did to see how fast it would swap banks. Answer? pretty damn
fast! The hard drive image is similar, but instead of loading it from
high memory, it gets loaded directly from the prodos file at whatever
offset is necessary to produce that particular frame. that disk will
run on any A2 with a floppy drive, whereas the hard drive image
requires an actual CFFA or MicroDrive to run.

According to my calculations, since the screen memory is 1024 bytes
(ok, i know it's really less when you take out the screen holes and
such), and my frames are exported from Quicktime at 25 frames per
second, you can fit around 21 minutes of uncompressed GR video on a
32meg partition. Probably about 45 minutes if you add some form of
compression. CiderPress seems to compress the movies at about 40-50%.

Michael Mahon has written a program that pulls the frames from the CF
HD at a rate of about 66 frames per second, so it will need a delay
loop to time it back down to 25 fps. but it does show the bandwidth the
A2/CF combo is capable of. And yes, actually getting the frames is much
more complicated than displaying them. Especially since i have an
actual ][ doing the TIFF to GR frame conversion.

stay tuned to this project. we'll probably have something real-time 25
frames per second (delay loop figured out) in the next couple weeks. i
have 9 full videos converted at this point.

-f-




Craig Bower wrote:
> Hi,
>
> I had a cursory look at your code for "playvideonodelay" from the Billy Idol
> disk.
> Are you actually specifying each line on the lores screen, indexed by the
> Y-register to move the data?
>
> I was thinking of putting together a LORES movie projecter ages ago, but
> alas vaporware as I had little time to work on it.
>
> If you'd like I can post a routine to move an entire "buffer" to the LORES
> screen very quickly using minimal code.  All you need to do is
> specify the "offset" in memory to the originating buffer and then JSR to the
> routine.
>
> The major limiting factor to my routine is it can put data up so fast you'll
> run out of memory (even on a CF card) real fast in 100% real time.
> Of course that's one of the reasons I sixxed my project as I don't have time
> to create 128-256 MB worth of LORES video frames! :)
> 
> Cheers,
> Craig