ixus90/sd790 IS porting - page 2 - DryOS Development - CHDK Forum

ixus90/sd790 IS porting

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Offline brake

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  • IXUS90IS / SD790IS
Re: ixus90/sd790 IS porting
« Reply #10 on: 04 / October / 2008, 03:27:32 »
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Hrm. The ixus90 appears to have 12-bit depth for it's RAWs. Don't most of the other P&Ss have a 10-bit depth? It still doesn't explain why when I'm reading the RAW buffer the data is incorrect.

Raw Size = 0xEC04F0 (from firmware)
Width = 0xE88 (from firmware)
Height = Width - 0x3B4 (from firmware)
Raw Size = Width * Height * 12-bit / 8-bit (bytes)

[edit]
DNG4PS assumes 10-bit depth, thus if I only save the equivalent of the Width*Height*10-bit DNG4PS will recognise the file but of course the RAW file I end up is essentially noise.
« Last Edit: 04 / October / 2008, 03:51:52 by brake »

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Offline fudgey

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Re: ixus90/sd790 IS porting
« Reply #11 on: 04 / October / 2008, 05:53:29 »
Hrm. The ixus90 appears to have 12-bit depth for it's RAWs. Don't most of the other P&Ss have a 10-bit depth? It still doesn't explain why when I'm reading the RAW buffer the data is incorrect.

Assuming it's true, this is great news!

AFAIK, all previous models that run CHDK have 10-bit RAW. But it's no big surprise that 12 bits could be available in a new model, since Canon's been using 12-bit A/D converters with 2 LSBs disabled in hardware.

There's been some discussion elsewhere on this forum about the internals of CHDK RAW files... you could try stripping 2 bits out of your files to find out if they are valid. Or patch dcraw to support 12-bit CHDK CRW, whichever is less work.

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Offline brake

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  • IXUS90IS / SD790IS
Re: ixus90/sd790 IS porting
« Reply #12 on: 04 / October / 2008, 12:25:54 »
Well, that is exactly what it appears to be. Made a program which stripped the last 2 bits from each 12 bits then converted the resulting file with dng4ps and here's what I get. Picture within noise, but the important thing is the picture. I haven't read up on how RAW files are encoded, so I suppose that's my next task. I'm glad this was worked out cause I was losing motivation as to solving the problem :)

For some reason the RAW files don't always work. You'd expect every image to come out something like the one I've output below but sometimes I end up with files with chunks of the image removed, and other times where it just looks like you're tuning a TV.
« Last Edit: 04 / October / 2008, 13:23:17 by brake »

Re: ixus90/sd790 IS porting
« Reply #13 on: 24 / October / 2008, 03:51:23 »


Re: ixus90/sd790 IS porting
« Reply #14 on: 29 / October / 2008, 18:42:38 »
Hi everyone. Has there been any more progress with this port? It's been awhile with out an update... oh keep up the good work!!

Re: ixus90/sd790 IS porting
« Reply #15 on: 01 / November / 2008, 12:22:38 »
I have no programming knowledge, but just wanted to let you know i'm cheering you on in this endeavor!!  can't wait to use this!! does anyone know why canon doesn't do this or make it easier?

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Offline brake

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  • IXUS90IS / SD790IS
Re: ixus90/sd790 IS porting
« Reply #16 on: 03 / November / 2008, 00:41:18 »
Apologies about the lack of updates. Uni and real life have caught up with me. I hope to do some more work soon.

Re: ixus90/sd790 IS porting
« Reply #17 on: 03 / November / 2008, 22:55:09 »
Apologies about the lack of updates. Uni and real life have caught up with me. I hope to do some more work soon.

No need..your already giving us a favor... I was just hoping to use/test it while I am on my trip in few weeks....


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Offline brake

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  • IXUS90IS / SD790IS
Re: ixus90/sd790 IS porting
« Reply #18 on: 28 / November / 2008, 05:46:49 »
I'm really not getting any time to work on this. I've attached what I was up to, which isn't anything past my last update post. I still don't understand why RAWs do what they do, the spinwheel doesn't work, movie stuff isn't even copied from the firmware. You'll have to download chr's encoder if you wish to encode the firmware.

The first archive is the platform/ixus90, loader/ixus90 and modified header files. It's seriously been a while since I've looked at this so if you require any more files just send me a PM. The second archive is the IDA database.

ixus90_chdk_281108.tar.gz - 1.00MB
ixus90.7z - 19.19MB

Re: ixus90/sd790 IS porting
« Reply #19 on: 14 / December / 2008, 14:22:51 »
Hi Brake,

Thanks so far for doing this great work!

I will be watching this area (added the RSS feed to my phone), I really like all the options the CHDK offers and I can't wait to try them with my IXUS 90 IS!

 

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