Who know about G9B format detail?

By Chaom

Rookie (21)

Chaom's picture

20-08-2017, 09:23

I developing an application on Windows and Linux to view MSX graphic files.
And I have problem about G9B format.

I completed the BitBuster decompression code and no have problem for any file.
But it can not display correctly for any G9B file except only uncompressed 16 bit color.

The compression structure in G9B is
block_count DB number of block
repeat block_count {
block_size DW number of compressed bytes
data DS (block_size)​
}

I don't know the data structure for YUV YJK 2 or 4 or 8 bits
or does anyone have some sample uncompressed G9B files for testing.

Thank you everyone.

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By msd

Paragon (1371)

msd's picture

20-08-2017, 15:53

The data structuur of the yuv/yjk etc is in the format of the v9990. It helps if you download the v9990 documentation . Also you can make some files by yourself when you download the tools at Teambomba.
Also contains more info about the g9b format.

By Grauw

Enlighted (7893)

Grauw's picture

20-08-2017, 16:31

YJK mode is the same for V9990 as for V9958 (screen 12), including optional YAE (screen 10/11). YUV is the same as YJK but with G and B switched in the formula for better colour distribution. See the V9990 and V9958 application manuals here.

I did some V9958 YJK visualisations here. Also there’s a good explanation here.

By Chaom

Rookie (21)

Chaom's picture

20-08-2017, 17:21

OK, I read V9990 Programmers Manual at http://msxbanzai.tni.nl/v9990/manual.html
and not found any problem in color format of my application.

Yesterday I tried to use bmp2g9b.exe from TeamBomba to convert some files,
but every files I converted are black G9B picture files. (color count = 1)

I used ViewMSX.exe to view other sample files and no problem.
I think a problem is in decompression process and I must debug for a while
but I still can't convert any bmp file to G9B format.

Thank you.

By msd

Paragon (1371)

msd's picture

20-08-2017, 17:39

Make sure the input format bmp is correct. For example it problabky doesn't work if it is a 32bit bitmap file

By Chaom

Rookie (21)

Chaom's picture

21-08-2017, 07:27

I try to use other graphic application and it's work. I can convert bmp to G9B now.
Thank you for your advice.

By msd

Paragon (1371)

msd's picture

21-08-2017, 10:12

@Chaom: Your are welcome. As I'm the other of this format you can ask me for more details if required.

By Chaom

Rookie (21)

Chaom's picture

22-08-2017, 12:12

I found Bit buster compression of G9B has a bit difference to Bit Buster file compression.
Uncompressed G9B has no problem at all. I'm fixing it.

By Chaom

Rookie (21)

Chaom's picture

23-08-2017, 14:28

Hooray! I got it.
LT2 and G9B format already supported.

https://sites.google.com/site/slumpmax/development/msx-home-computer/msxsee

By sd_snatcher

Prophet (2946)

sd_snatcher's picture

09-04-2018, 23:56

Where are more details about the bitbuster compression used in G9B files available? Piotr is interested in adding support for it in RECOIL.

By ericb59

Paladin (826)

ericb59's picture

20-03-2019, 17:38

Hi,

Unfortunately no one answered SD_SNATCHER. Too bad because I also need to know what is the difference between the "classic" bitbuster and the one used in the G9B image format.

My MSX profile