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Forum Index : Microcontroller and PC projects : PicoMiteHDMI framebuffer thoughts

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Mixtel90

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Joined: 05/10/2019
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Posts: 6780
Posted: 02:40pm 18 Aug 2024
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Hmmm... Dunno...
The RP2350 isn't using a PIO for video generation, but whether that makes any difference I don't know. Only having half the RAM certainly *will* make a difference as there isn't room to increase the size of the framebuffer. I assume that there's some RAM required to handle the magic colours.
Mick

Zilog Inside! nascom.info for Nascom & Gemini
Preliminary MMBasic docs & my PCB designs
 
Bleep
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Joined: 09/01/2022
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Posted: 03:26pm 18 Aug 2024
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The HSTX isn't simply a very fast parallel to serial converter, you can insert in the data path an extra bit of logic called a command expander, which I suspect is what is helping to do the colour mapping, so probably not, & I'm probably completely wrong, but who knows. ;-) There also is something called a TMDS Encoder, in the SIO logic, which may also be responsible?
Regards Kevin.
Nope wrong, looks like Peter is doing it all on the second core.
"I've got the HSTX example working nicely and have moved the processing onto the second core. I'm using two linebuffers which one of which is filled while the other is being output rather than outputting from the framebuffer direct. This allows me to do things like merge a top layer over a background layer in the code and then move that composite to the line buffer when required. I also use mapping arrays so a framebuffer that is 640x480x4bits can be mapped to any of 256 colours."
Edited 2024-08-19 06:34 by Bleep
 
matherp
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Joined: 11/12/2012
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Posted: 10:34am 19 Aug 2024
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UPDATE

I couldn't get RGB565 or RGB555 working  

HOWEVER

RGB888 is working nicely  

This means that all mapping tables now allow any of the colours to be mapped to a full RGB888 value allowing things like 256 grey shades and a new mode 6 - 320x240x1677721 colours.

This is still just standalone HSTX testing with no integration with MMBasic so I could hit some bus bandwidth issues but so far so good
Edited 2024-08-19 20:36 by matherp
 
Mixtel90

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Joined: 05/10/2019
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Posted: 10:37am 19 Aug 2024
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This is getting silly.....   :D
Mick

Zilog Inside! nascom.info for Nascom & Gemini
Preliminary MMBasic docs & my PCB designs
 
PhenixRising
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Joined: 07/11/2023
Location: United Kingdom
Posts: 857
Posted: 11:00am 19 Aug 2024
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  Mixtel90 said  This is getting silly.....   :D


I like silly    
 
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