The astonishing unpopularity of "dynamic-highres"

[TjLaZer]

Wasn't Dynamic Hi-Res from NewTek? In Digi Paint from what I remember?

[buzz]

Were these formats not all the same though ? You have hires interlace 4 bitplanes with a sliced palette (reloading 15 new colours with the copper each frame) and also sliced ham modes with lowres interlaced but a sliced ham palette (less fringing) ?

I was coding on a intro advert for exotica back in 1998. I should really finish it. It has a few images in "dynamic hires) (or pchg) format at the top 2 3rds of the screen , and a lowres scroller (2 pixel), in the bottom. I'm sure I could do a 1 pixel, with some optimisation. I was going to do something with the 4 sprites available too..

The pics did look pretty good though..

[buzz]

Digipaint does interlaced ham. but its a good proggy for sure.

[mr_a500]

Digi-View 4.0 could create dynamic highres, but not Digi-Paint. It would have been awesome if Digi-Paint 3 could handle dynamic highres. I wonder why they didn't add it.

Were these formats not all the same though ?

The true "Dynamic Hi-Res (TM)" is by NewTek and does not display properly in Visage or Viewtek even though they display SHAM and PCHG. MacroPaint will only load SHAM and Dynamic and saves Dynamic. I think there are also a few other filetypes called AHAM, ARZ0 and ARZ1 (but they must be very old and obsolete because I've never heard them mentioned anywhere except in a HAM-E advertisement).

When I'm saying dynamic highres, I'm really talking about all the formats, not just the NewTek one.

[buzz]

It may not be possible with an OS friendly app to display dynamic hires. Or at least, not using an amigaos screen with custom copperlist anyway.

[AmigaHeretic]

There's one of the NewTek Dynamic Hi-Res pictures on this site.  Came from one of the NewTek demos.

http://www.amiga.org/gallery/index.php?n=282=30


AmigaHeretic

[mr_a500]

I just did some speed tests to see how much the system actually slows down while viewing dynamic highres. I converted a jpg (CPU intensive task, I assume) with HamLab from Workbench screen without viewing it, then I converted the same jpg while viewing a 594x594 dynamic highres image in Visage and timed with a stopwatch. I set HamLab to beep when finished so I would know when it finished while I was viewing the dynamic image. I did three tests:

(in seconds)
No dynamic: 34.81  Dynamic: 35.02
No dynamic: 34.88  Dynamic: 35.04
No dynamic: 34.71   Dynamic: 34.96

As you can see, there's only a slight difference and this could even have been caused by flipping to the dynamic highres screen.

Then I tried the same thing on my Amiga 1000 (stock except 1Mb RAM), except viewing a 640x400 image in Shazam (Visage doesn't work in WB1.3) and converting a smaller jpg in HamLab. It was a whole different story:

No dynamic: 2:48.01  Dynamic: 6:42.38
(I only did one test because it took too bloody long)

So, the lack of "dynamic highres slowdown" on my A500 must have something to do with my upgrade (maybe Fast RAM?). Still, viewing a 640x400 dynamic highres image on an A1000 took "only" 7 seconds (and looked totally amazing for a 1985 computer!), so I still think dynamic highres should have become the standard for viewing high-colour highres images on the OCS/ECS Amigas.


@SamuraiCrow
Thanks for the detailed info. :-)

[sdyates]

Yes, but that image no longer displays on either of my a3000s (3.1). I have noticed that the newtek demos also have troube running and eventually crash. Is this a problem with 3.1 roms or the ECS? My original one also had problems with displaying dynamic highres.

I never had trouble on my A500.

Thoughts anyone?

[mr_a500]

Forget the NewTek demo. Lots of old NewTek stuff crashes on my upgraded A500. Just get a copy of HamLab and load any jpg or gif (or even the NewTek image) and you'll have no problem.

[Tomas]

And how did you measure this? I don't mean the decoding the picture and writing it to memory... that is pretty much as fast as regular pictures. The slowdown comes from the copper banging the colour registers, for the whole duration the picture is displayed. With stock A500 this would take pretty much all time from CPU, especially when combined with the highres 4 planes DMA drain...

And on a stock amiga you normally run a bunch of programs at the same time you are watching still photos? I sure as hell would be interested in this if i knew about it back then.

I honestly dont care if the cpu and co processors is working at 90% capacity when i have nothing running in background that needs the power.

[mr_a500]

I just found another great use for dynamic highres: displaying screenshots containing copper "rainbows" (game or Workbench screenshots).

Example: my "Rainbow Mania" screenshots (on Amiga.org) have blue copper rainbows in the background. I had to take the screenshots with WinUAE because there is no possible way to capture the rainbow on a real Amiga. When I then try to display the screenshot on my real Amiga, it can't be displayed at the resolution it was taken at because the copper rainbow uses up more colours than should be possible at that resolution. So, I can only view the highres screenshot in lowres HAM.

But with dynamic highres, I can view it in highres and still see the copper rainbow. Converting with HamLab (dithering off), it is nearly perfect. I say nearly because the original must be saved as gif and gif uses fixed 256 colour palette missing some colours the Amiga has (and jpg is "lossy"). Oh I wish HamLab could load PNG!

Edit: What am I thinking? I can just save the original as 24bit ILBM. duh.

[Piru]

@mr_a500

jpg is "lossy"

Use jpeg quality setting of 100% ?

[mr_a500]

Use jpeg quality setting of 100% ?

I already did. It still had artifacts after converting to dynamic highres.

[blakespot]

Continuing this thread... I just installed NewTek's DemoReel #3 on my Amiga 1000, and when the Dynamic HiRes image is supposed to be displayed, nothing happens - the demo moves on.

This is an NTSC Amiga 1000 with 512K CHIP, 2MB FAST, and EHB is supported, here.

Should this machine be able to display dynamic high res images?





bp

[ChaosLord]

@mr_a500

Use jpeg quality setting of 100% ?

Even when you set jpeg quality to 100% the result is still lossy and damaged.  Its a scam.

[ChaosLord]

I can't remember which demo reel is which so I can't remember what year they came out so I can't remember how much chipram they required.

Here are the possibilities:
A. Needs 1MB Chipram

B. Needs 512k Chipram and somehow you have a program running on your Amiga that is using some of that.  Like for example you probably have 4 floppy drives connected and each drive use chipram buffers.  Or you have a hard drive connected which probably has very LARGE chipram buffers.

Reduce your chipram consumption and watch it start to work.