HAM Video Variants - FS-UAE vs Real Amiga Hardware

[movec]

Originally Posted by matthey

It looks and sound great, especially for the resolution, but the file is big at 493MB for 3 minutes. You need AGA, a fast CPU (>=68040?), fast drive interface (3+ MB/s?) and a large drive. There are probably fewer than 5% of active Amiga owners who could play the video on real hardware. HAM8 video may have been good for fast and easy low compression decoding years ago but it is primitive with the CPU performance and video encoding technology of today.

You are certainly right (beside the detail that it's an AGA8 video (not a HAM video), however, the amount of data is the same for HAM8).
Of course you have to compromise with the bandwith (I/O and/or memory) that you have on a given Amiga. Better compression would be great, but on lower-end Amigas you don't have enough compute power for any advanced decompression algorithms either. Since everything is so compromised on these old machines, using compression/decompression or just reduced resolution gives pretty similar results IMHO.
It would be interesting if the emulator would also simulate different bandwidth configurations, then it would be easier to compare Amiga models.

[matthey]

Originally Posted by movec

(beside the detail that it's an AGA8 video (not a HAM video)

That is indeed impressive for only 256 colors per frame. The dithering must be perfect for this video. I notice no banding which can be visible with sky using simple dithered 16 bit (565) chunky.

Not using HAM8 would probably make it possible to allow ModePro to promote the video to RTG so many more Amigas could play it at least. Storing and displaying the data in planar is less than efficient even at 8 bit though. I wonder how things would have been different if the Amiga had HSV (originally planned for the Amiga chipset including for HAM which was more useful) or had received chunky with AGA (could have and should have along with being released 2 years earlier).

[movec]

Originally Posted by matthey

Not using HAM8 would probably make it possible to allow ModePro to promote the video to RTG so many more Amigas could play it at least.

What does ModePro actually do? I have a Picasso IV - isn't there a way to directly pass an 8-bit chunky format to the graphics card? Or does it only take a 24-bit or planar (as input)? Since I generate the data I can generate any format - avoiding any conversion by the Amiga processor (itself) is key to not slowing it down.

However, if all that takes to have it in AGA8 (no HAM) then we are done already, because this looks pretty much the same as the HAM8 version (at least for these kinds of videos).

[matthey]

Originally Posted by movec

What does ModePro actually do? I have a Picasso IV - isn't there a way to directly pass an 8-bit chunky format to the graphics card? Or does it only take a 24-bit or planar (as input)? Since I generate the data I can generate any format - avoiding any conversion by the Amiga processor (itself) is key to not slowing it down.

ModePro does what you tell it to. It has all kinds of options and filters to selectively promote and/or convert just about any screen mode or name. Converting from Amiga planar to RTG modes is one of the best features and is super easy. P96 patches the graphics.library so using AmigaOS rendering functions usually works on RTG screens if OS friendly (most productivity software works but few games). Everyone with RTG should have it.

http://aminet.net/package/util/cdity/ModePro

Originally Posted by movec

I have a Picasso IV - isn't there a way to directly pass an 8-bit chunky format to the graphics card?

Sure. Just select/use an 8 bit RTG gfx mode for your screen and you will have it. I believe CGFX and P96 use the same 8 bit format (pseudo-chunky LUT8). See the P96 and CGFX Software Developer Kits (SDK) for more info.

Originally Posted by movec

Or does it only take a 24-bit or planar (as input)?

It really depends on what the gfx card supports but most support a pseudo-chunky LUT8 mode. Some gfx cards only support or prefer little endian modes so be careful there (not a problem if reading/writing a byte at a time). CGFX and P96 support most of the common display formats including both big and little endian formats. See the SDK includes for formats supported.

Originally Posted by movec

Since I generate the data I can generate any format - avoiding any conversion by the Amiga processor (itself) is key to not slowing it down.

Yes, it would be fastest to support a native gfx format of the display device and not have to convert.

Originally Posted by movec

However, if all that takes to have it in AGA8 (no HAM) then we are done already, because this looks pretty much the same as the HAM8 version (at least for these kinds of videos).

ModePro could probably convert the AGA8 to RTG 8 bit data but it is nicer and faster not to convert like you said.

[movec]

Originally Posted by matthey

ModePro does what you tell it to. It has all kinds of options and filters to selectively promote and/or convert just about any screen mode or name. Converting from Amiga planar to RTG modes is one of the best features and is super easy. P96 patches the graphics.library so using AmigaOS rendering functions usually works on RTG screens if OS friendly (most productivity software works but few games). Everyone with RTG should have it.
http://aminet.net/package/util/cdity/ModePro

Sounds very interesting (the more I think about it - thanks for the description. If it speeds up AnimFX then 25 FPS/lores with 8 bit sound may be possible for about 3 mins on my Amiga (it's already fast enough in native mode, but only from the accelerator board's memory (for about 1 min), not from Zorro memory).

BTW, I will soon upload a new HAM8 video, just need to find a good way to compute the total number of colors - this should be a very high number and I am curious what it is. The sky is indeed interesting to watch&compare in AGA8 and HAM8 videos (thought about your comment, as I inspected the pixels

[movec]

And here is now a HAM8 video with color count ...

[ Show youtube player ]

That's what I was originally aiming for .. enjoy.

The video description also contains sizes&color counts of downscaled variants of the same video. AGA8 doesn't look much different, anyways, the fun-part was the HAM8 decoder to compute the color count

[emufan]

while i hate the content, the technical part is great

[matthey]

Originally Posted by movec

And here is now a HAM8 video with color count ...

The HAM8 video looks more colorful or at least has more brightness variation (I wonder how a HSV HAM8 would have looked). I did notice some minor banding in the sky and on the girls face rarely. There isn't much difference compared to the AGA 8 bit video which is more impressive and looks better, IMO. Maybe the video tools and editing were better on the 8 bit video?

[pandy71]

Originally Posted by movec

And here is now a HAM8 video with color count

Cursor color constantly changing - seem or this is not HAM or it is HAM but with CLUT optimization for every frame.

[NorthWay]

If you are taking creative liberties then you could do SHIRES HAM8 too which should give more room to morph the colours right.

[movec]

Originally Posted by matthey

The HAM8 video looks more colorful or at least has more brightness variation (I wonder how a HSV HAM8 would have looked). I did notice some minor banding in the sky and on the girls face rarely. There isn't much difference compared to the AGA 8 bit video which is more impressive and looks better, IMO. Maybe the video tools and editing were better on the 8 bit video?

The AGA8 and HAM8 look pretty much the same except the sky patterns appear different sometimes. The conversion pipeline was the same, I didn't use any other edit tools. I think the resizing makes most of the difference (downscaling to the Amiga screen size), the upscale in FS-UAE is pretty decent. This video has more objects in the distance which also makes it look less clear and there is more out of focus material in the video, which doesn't come out that clear either. It's interesting though that the HAM8 video compresses (with anim7) slightly better than the AGA8 variant.
What would be the difference of a HSV HAM8?

[movec]

Originally Posted by pandy71

Cursor color constantly changing - seem or this is not HAM or it is HAM but with CLUT optimization for every frame.

Every frame has its own optimized HAM8 64 colors palette (independent of the other frames). The concept is exactly the same as with the AGA8 conversion, just with a HAM8 picture format. The cursor colors change because all the colors (except color reg 0) are changing in each frame. That's the reason why I keep the cursor on the screen, to make this somewhat visible.

One could actually display the color palette in each frame, simply by having some fixed rectangles of each color reg hardcoded in the HAM8 picture. Same with AGA8. This would make more clear (or flashy <g>) how this works.

BTW, the AGA8 hires variant has 464700 different (unique) colors total.

[movec]

Originally Posted by NorthWay

If you are taking creative liberties then you could do SHIRES HAM8 too which should give more room to morph the colours right.

Yeah, it could be interesting just to see how this works out. Now that you say it, in principle png2ilbm allows to convert any size using the HAM (or AGA) conversion, Thus, I could convert a full HD video to "HAM-HD" - and then backconvert it to 24bit and play it (since there is no other way to play it). In the worst case it looks pretty much the same

[matthey]

Originally Posted by movec

The AGA8 and HAM8 look pretty much the same except the sky patterns appear different sometimes. The conversion pipeline was the same, I didn't use any other edit tools. I think the resizing makes most of the difference (downscaling to the Amiga screen size), the upscale in FS-UAE is pretty decent. This video has more objects in the distance which also makes it look less clear and there is more out of focus material in the video, which doesn't come out that clear either. It's interesting though that the HAM8 video compresses (with anim7) slightly better than the AGA8 variant.

Yes, I think the original car video was cleaner and more professionally edited. The music video could have had the brightness toned down as well as better focus (not to mention better camera positioning/centering which was not so important for your purpose). It might have been better to compress the same video as AGA8 and HAM8 to compare.

Originally Posted by movec

What would be the difference of a HSV HAM8?

I expect better transitions around light and perhaps less banding (the color can stay the same while the brightness changes). We don't know for sure without simulating HSV HAM and I don't know that it has ever been done. The HSV HAM idea was taken from expensive flight simulators which Jay Miner had looked at on a tour. When the Amiga chip set was converted to RGB, Jay thought HAM would be much less useful which is why he wanted to remove it.

[movec]

Originally Posted by matthey

It might have been better to compress the same video as AGA8 and HAM8 to compare.

That was my original plan I did exactly that in a video where both are shown side-by-side. However, it appeared to be just boring because the videos look exactly the same at 25 FPS, only if one views it frame by frame some small differences become visible (e.g. some of the sky patterns and some other small areas a few times). I also thought about magnifying those sections, but that didn't really cut it either, since the very few spots where they differ are in very different parts of the screen and video. One would need to mark those locations etc. one could compute a difference-picture though. HAM6 vs HAM8 (or OCS vs AGA8) would probably be different enough that smaller frames side-by-side show enough difference. I also though about just cutting the sreen in a half, and doing the left side in AGA8 and the right side in HAM8, but since they are so similar, it's even hard to notice ...

Originally Posted by matthey

(the color can stay the same while the brightness changes). The HSV HAM idea was taken from expensive flight simulators which Jay Miner had looked at on a tour. When the Amiga chip set was converted to RGB, Jay thought HAM would be much less useful which is why he wanted to remove it.

That would have been indeed an interesting graphics mode. I wasn't aware of the HSV aspect of the flight-sim-HAM story; makes more sense now

[TEG]

Would love to see it on a real A500 with fast memory and a real A1200 with fast memory too.

[Thorham]

Originally Posted by matthey

We don't know for sure without simulating HSV HAM and I don't know that it has ever been done.

Normal HAM is trivial to emulate on the peecee (have done it), so I suspect HSV HAM will be easy enough.

[matthey]

Originally Posted by Thorham

Normal HAM is trivial to emulate on the peecee (have done it), so I suspect HSV HAM will be easy enough.

Sure. Software display of 32 bit images compressed with HSV HAM would show us what it looks like in comparison to RGB HAM but that is the easy part. Tools are needed to convert and dither true color images to HSV HAM which don't exist. This is kind of like HAM on the early days of the Amiga where there was hardware support but few creation and conversion tools so it was rarely used. I doubt anyone will bother creating all the software needed to see how good HSV HAM would have been and it is unlikely the bandwidth savings is worthwhile to implement in hardware today, especially without a common standard. The HSV YCbCr color model is used in JPEG and MPEG so there are modern related compression applications which do have hardware support.

[movec]

Originally Posted by matthey

ModePro does what you tell it to. It has all kinds of options and filters to selectively promote and/or convert just about any screen mode or name. http://aminet.net/package/util/cdity/ModePro

I gave gave it a try with AnimFX, but this doesn't work, it only produces a Guru. I simply promoted the AnimFX(program)/PAL lores screen. Have you tried it with AnimFX?

[gulliver]

Originally Posted by movec

I gave gave it a try with AnimFX, but this doesn't work, it only produces a Guru. I simply promoted the AnimFX(program)/PAL lores screen. Have you tried it with AnimFX?

NewMode is less powerfull but easier to handle (it is in Aminet).

There is a tutorial for it in Youtube.

[ Show youtube player ]