IXUS190 porting attempt

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    Re: IXUS190 porting attempt
    « Reply #20 on: 01 / June / 2017, 11:06:52 »
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    Many people have made ports just by copy/pasting and updating the platform code.
    This way is not for me definitely. I used to work while understanding what I'm doing.
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    Updating the platform code mostly means the .c files, including inline asm (codegen files for non digic 6 cameras), #defines in the include files, variables in the platform makefile.inc files, and any stubs not found by the sig finder.
    But where is an up-to-date list of the exact lines in the exact files - to modify?

    I'm sorry, but I'm not going to proceed until I have a clearest understanding of why exactly
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    CHDK is built in such a way that the start of the file contains the code from entry.S
    Because I can't proceed - I simply don't know how.

    I have no idea of what to do next. I'm feeling like an asshole already. http://chdk.wikia.com/wiki/Adding_support_for_a_new_camera looks humiliating.

    So weird it all.

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    Re: IXUS190 porting attempt
    « Reply #21 on: 01 / June / 2017, 13:51:47 »
    But where is an up-to-date list of the exact lines in the exact files - to modify?
    There is no such list. Pretty much every file in the platform directory needs some adjustment.

    If you want to understand the code, you have to actually go through the code, file by file. When you run into something you don't understand, grep the code to see how it is used, compare a few different ports to see how the differ, consult the relevant arm / gcc / binutils manuals, ask here.

    That's how all the rest of us learned.
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    I'm sorry, but I'm not going to proceed until I have a clearest understanding of why exactly
    That's your choice. Personally, I find that documentation is good for learning the big picture and finding starting points, but real understanding only comes from working on the code.

    I'm sorry, but I'm not going to proceed until I have a clearest understanding of why exactly
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    CHDK is built in such a way that the start of the file contains the code from entry.S
    Because I can't proceed - I simply don't know how.
    I don't understand why this is such a stumbling block. As I explained in my previous post, it's already set up in the makefiles and doesn't need to be changed per port, so you can just take it as a given. If for whatever reason you want to know all the details, trace through the makefiles and look everything up in the binutils manuals.
    Don't forget what the H stands for.

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    Re: IXUS190 porting attempt
    « Reply #22 on: 02 / June / 2017, 14:26:35 »
    I noticed that this camera shoots photos with some geometrical distortion kind of "fisheye"-alike. I wonder if CHDK might help with this. Otherwise I'm considering to return the camera back to the store.

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    Re: IXUS190 porting attempt
    « Reply #23 on: 02 / June / 2017, 21:28:24 »
    I noticed that this camera shoots photos with some geometrical distortion kind of "fisheye"-alike. I wonder if CHDK might help with this. Otherwise I'm considering to return the camera back to the store.
    CHDK won't fix distortion in camera jpegs. Using CHDK raw would allow you to apply distortion correction in a raw processing program, with less loss of quality than you'd get correcting it jpeg.

    I doubt you'll find a P&S with a 24 mm equivalent lens that doesn't look distorted in some way.
    Don't forget what the H stands for.


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    Re: IXUS190 porting attempt
    « Reply #24 on: 05 / June / 2017, 07:51:02 »
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    I doubt you'll find a P&S with a 24 mm equivalent lens that doesn't look distorted in some way.
    I wonder where does such distortion originally come from. Is the RAW image gets shot already distorted (because the lens is round and the matrix is plain)?

    I had previously a cheap camera bought 10 years ago. It produced excellent photos - no visual fisheye distortion, nice sharpness and color, etc. But I occasionally broke it. Interesting why this old camera had no distortion, but IXUS190 does. The old camera probably had some common-sized matrix - nothing special.

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    IXUS190 porting attempt
    « Reply #25 on: 05 / June / 2017, 08:27:10 »
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    I doubt you'll find a P&S with a 24 mm equivalent lens that doesn't look distorted in some way.
    I wonder where does such distortion originally come from?
    Point & shoot cameras have simple very inexpensive optical zoom lenses.  Making such a lens without any distortion at wide angles is next to impossible.  Maybe if you pay thousands of dollars for a DSLR lens you get very little distortion, but not with a $200 P&S camera.

    It's much cheaper for the manufacturer to try to correct any distortion via software after the shot.

    Quote
    I had previously a cheap camera bought 10 years ago. It produced excellent photos - no visual fisheye distortion, nice sharpness and color, etc. But I occasionally broke it. Interesting why this old camera had no distortion, but IXUS190 does. The old camera probably had some common-sized matrix - nothing special.
    The old camera likely had a much smaller zoom range and possibly a more limited wide angle position. That would make it possible to design with less distortion, and easier to correct in software.
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