shmups.system11.org

AKURA DREAMCAST HDMI BOX WITH SCANLINER

Our much anticipated secret project AKURA is finally ready for production.
It's an HDMI video box for your beloved Dreamcast console. As our other legendary products, it has a Scanliner function as well. Just like the Toro or Hanzo, you don't need to modify your console,it's a plug 'n play solution.
Here is a video proof of our pre-production sample

https://youtu.be/C1TfWrrlgJc

https://flic.kr/p/QeTAc8
https://flic.kr/p/QeTzVg
https://flic.kr/p/Q1Yugf

We will start to take Pre-orders from mid January... Prices TBA...


Thanks for your support.



Team Beharbros
http://www.beharbros.com

So it's basically an analog-RGB-to-HDMI transcoder with a built-in line doubler?

It is not an upscaler. 1:1 video converter with scanline generator.

Looks cool!

Nevermind

This only works on 480p games, then? AFAIK many (most?) TVs do not support 480i over HDMI.

Yes, other games can work with the VGA switch trick, however still some games are not VGA 480p compatible.

Nice effort!

Did you pay attention to the proper sampling and A/D conversion ? As you know the DC does output a 640x480p signal inside a 720x480p border, which causes a resolution loss on almost all VGA to HDMI converters. Does the Akura report as 640x480p/VESA or 480p/SMPTE to the display ?

Can you please take a snapshot of a 1-pixel checkerboard pattern (e.g. the energy/power bars on GGX) ? If you set the display to 4:3 as long as you do the proper sampling, you get a 1:2 integer pixel scale on your 1080p display (1280 active columns on a 1440 columns area).

And do you integrate scanlines on a digital level or analogue prior to the A/D conversion ?

Thanks. It shows 640x480. It can't fix that resolution issue. Because it's a general purpose converter, just like the Hanzo&Toro an extra scanliner cable enables VGA input for it, so you can use other consoles and PC with it. 480p,720p and 1080p resolutions are supported.
OK, I will take a photo tomorrow.
Scanlines are integrated before the conversion.

That's ok, but you should make buyers aware of this when they place their (pre)orders. Advertised like this one might expect the same quality the OSSC would deliver (where you can manually switch between the two sampling rates).

Fun fact about all those "general purpose" VGA to HDMI converters: most of the ICs used on these are actually able to detect the proper SMTPE timing of the input resolution if they're fed with a component signal (even if they don't offcially support YUV inputs), so my hope would be that the ICs can be forced to apply sampling matching the SMTPE timing while working with a RGBHV signal.

If you have the proper equipment on hand, do a comparison yourself. If you transcode the DC's VGA signal to component first and then use a component to HDMI converter (can be as cheap as it gets), it will suddenly resolve the full resolution (which you can easily spot on any 1-pixel checkerboard pattern).

Thanks for your advice. It can be done with an fpga and some coding.
OSSC is in a different league so it's pricier.
There is always a tradeoff. The IC we are using is capable of component conversion too, but the image quality of rgb -> ypbpr-> hdmi is worse than direct rgb to hdmi when we tested.

If you're really sampling a 720 pixel wide image using only 640 samples, I think that the quality loss from the misaligned sampling (introducing effectively a big horizontal blur) is going to be much worse than anything the colourspace conversion might cause.

marqs explained the numbers somewhere in the OSSC thread and I created this graphic http://pms.hazard-city.de/ossc_sampling.jpg trying to explain the difference between the two sampling modes.

You're effectively losing 43 columns of resolution, BUT to be fair: the very same thing happens on EVERY TV with a native VGA input and instead of blurring the whole image you only end up with a regular pattern of slightly blurred columns. Hence my advice to check it with a 1-pixel checkerboard pattern.

True, depending on how precise the Dreamcast's analog output is, you would only perceive a blur when the sample was taken close enough to the pixel boundary. So if the Dreamcast has very sharp analog output, a relatively small number of samples would show up as blurry.

Testing Guilty Gear X DC

https://youtu.be/kHmWDWJe-q4

https://flic.kr/p/QkdBko

This looks great, but I have a Hanzo is what I am saying right now.

Super interested in one of these though.

240p usually not, but I'm sure 480i is in the HDMI spec.

For RGB 480i games you need to try the VGA switch trick. While booting immediately change the RGB/VGA switch from RGB to VGA works with most of these games. Some games can be playable with VGA patches too.

Not as far as I can tell, although the specs are annoyingly secret (behind a licensing paywall, anyhow). IIRC I tried the OSSC's 480i passthrough on my Dell U2711 monitor and found that it was able to sync, but with a very messed up image (half height). That's a monitor that seems to support all the OSSC's esoteric timing modes (like 240x3 and 480x2).

Playing Guilty Gear X on a 21.5" PC monitor

https://youtu.be/wYZ9pMw-e2c

awesome!

Akura working with System Board Y2 KOF 2002
https://youtu.be/aZN6lhMovcc

Akura will be sold for $85 including shipping.
Preorders will be taken from February 7th...
Deliveries will start in March.

Does the hdmi transcoder scale to 1080p output or just digital 480p.

If you could scale the output to 1080p you could probably also scale resolution to properly display a 2x scale 960 in a 1080p frame.

Also you could bypass my tvs scaler helping my input lag

The current workaround is to plug it in to my framemeister and use the smart 2x.

just a couple questions/wishlist. I love your TORO btw I just wish it had proper aspect scaling built into the unit somehow.

It's not upscaling, it can only output 480p.

Since your here. I would love to know what you suggest for most people using your device on their tvs to correct their aspect?

Most tvs wide zoom over correct and I would love to hear it from the owner

It's adjusted automatically, I haven't found a way yet.

Try this: https://segaretro.org/List_of_Dreamcast ... reen_codes

Let's get ready to rumble!
http://www.beharbros.com/akura

Akura reviewed by Adam Koralik
https://youtu.be/zosZPMWQ_ZQ