SX230 1.01A CHDK .jpg files too small - page 2 - General Help and Assistance on using CHDK stable releases - CHDK Forum

SX230 1.01A CHDK .jpg files too small

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Offline reyalp

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Re: SX230 1.01A CHDK .jpg files too small
« Reply #10 on: 31 / March / 2013, 14:52:34 »
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Yes - but it does explains why sx230user got the wrong jpeg size when he had the override set to [ Off ].
It explains why it stayed at the last value he used before he set it to OFF. It does not explain why jpeg files under CHDK are smaller than without CHDK

Note, for this to be a valid test, the scene and shooting settings must be the same!
Don't forget what the H stands for.

Re: SX230 1.01A CHDK .jpg files too small
« Reply #11 on: 31 / March / 2013, 19:43:38 »
Noticed the same issue here, (not much of an issue because I never use the jpeg image for anything other than reviewing images in the camera)

but I wonder, if the exmem usage causing jpeg files to become smaller (due to lack of memory), then how does the camera create an 18.2MB raw file, and why cant it use the same method to write the jpeg?

on a side note, I wonder if there is a way to get the camera to display raw files, and thus move from saving RAW + jpeg, to just saving raw only and get better speeds and storage?

Re: SX230 1.01A CHDK .jpg files too small
« Reply #12 on: 31 / March / 2013, 19:50:08 »
but I wonder, if the exmem usage causing jpeg files to become smaller (due to lack of memory), then how does the camera create an 18.2MB raw file, and why cant it use the same method to write the jpeg?
If you mean the Canon firmware when you say "the camera" then you need to understand that "the camera" does not know CHDK is loaded and does not know anything about CHDK being there.  So it does the best it can finding space for its JPG files ... but does not realize that CHDK is using up some of its memory for CHDK code.   The camera does not need to create space for the RAW information - that's where it always put the raw information from the sensor.  CHDK hijacks the process and writes that buffer to the SD card (the 18.2 Mb you refer to).  No additional space required.

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And on a side note, I wonder if there is a way to get the camera to display raw files, and thus move from saving RAW + jpeg, to just saving raw only and get better speeds and storage?
In short - no.  There are hacks to prevent the cameras saving jpg but that does not change what it displays. And if you have any experience with RAW files,  you would realize you don't actually want to see them displayed on your camera's LCD screen.
Ported :   A1200    SD940   G10    Powershot N    G16

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Offline srsa_4c

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Re: SX230 1.01A CHDK .jpg files too small
« Reply #13 on: 31 / March / 2013, 19:56:40 »
but I wonder, if the exmem usage causing jpeg files to become smaller (due to lack of memory), then how does the camera create an 18.2MB raw file, and why cant it use the same method to write the jpeg?
CHDK is "stealing" some memory from the camera. This probably makes the Canon firmware believe that it only has a limited space for the new JPEG, thus the small size. RAW resides in a different part of memory, CHDK only has to save it (no additional memory is needed for that).

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on a side note, I wonder if there is a way to get the camera to display raw files, and thus move from saving RAW + jpeg, to just saving raw only and get better speeds and storage?
There's no way, AFAIK all Canon cameras need JPEG data for the playback mode display to work. If you don't need the full sized JPEG, set it to S size.


Re: SX230 1.01A CHDK .jpg files too small
« Reply #14 on: 01 / April / 2013, 02:16:11 »
good to know :)

Just cant see my self making much use of the jpeg images when the raw works so much better (one of the main reason why I always check the CHDk support list before purchasing a camera :)

« Last Edit: 01 / April / 2013, 02:55:53 by Razor512 »

Re: SX230 1.01A CHDK .jpg files too small
« Reply #15 on: 01 / April / 2013, 08:07:14 »


@sx230user
Using the current autobuild, run the following lua script and report the value. This will tell us how much canon heap is available, which will tell us whether a non-exmem build is feasible:

Code: [Select]
print(get_meminfo('sys').free_size)

I'm happy to do that but have no idea how to load or run a script.  If you can point me to instructions I'll give it a try, thanks

Re: SX230 1.01A CHDK .jpg files too small
« Reply #16 on: 01 / April / 2013, 08:17:14 »

You don't need a special build.  Based on the previous posts,  just leave the Override JPEG Quality set to [ Off ]  (reseting the camera if you needed to change it to be Off) and you should get the normal Canon quality.

I started the camera in CHDK mode, set the Quality Override to Off exited the menus and Alt mode and turned the camera off.  I restarted in Canon mode and took 2 pictures (same scene, same zoom, same settings in all cases described here), one at Canon Normal and one at Fine.

Turned the camera off and restarted in CHDK mode, left Quality Override at Off, and took another two pictures at Canon Fine and Normal.  The results were (MBs):

CHDK mode:
Fine - 2.1
Normal - 1.2

Canon mode:
Fine - 2.7
Normal - 1.2

Maybe I'm not "re-setting" correctly.  The CHDK mode file size was the same as before when I was setting the Override Quality values to SuperFine and Fine.

Re: SX230 1.01A CHDK .jpg files too small
« Reply #17 on: 01 / April / 2013, 08:55:21 »


@sx230user
Using the current autobuild, run the following lua script and report the value. This will tell us how much canon heap is available, which will tell us whether a non-exmem build is feasible:

Code: [Select]
print(get_meminfo('sys').free_size)

I did make a feeble attempt to do this by putting that statement into a txt file, naming it with a .lua extension and putting it in the Scripts folder in CHDK.  I ran it from the Alt menu and it reported:

***Started***
:1: attempt to index a boolean value

Apparently it was still running a few minutes later when I hit the shutter button again because it said aborted or something like that.  I never saw a value on the screen.


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Offline srsa_4c

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Re: SX230 1.01A CHDK .jpg files too small
« Reply #18 on: 01 / April / 2013, 09:16:42 »
I did make a feeble attempt to do this by putting that statement into a txt file, naming it with a .lua extension and putting it in the Scripts folder in CHDK.  I ran it from the Alt menu and it reported:

***Started***
:1: attempt to index a boolean value
Works for me using CHDK 1.2 (available from here: http://mighty-hoernsche.de/trunk/ ).
Make sure that the text editor you're using saves clean ASCII files, not unicode/UTF-8/... .

I started the camera in CHDK mode, set the Quality Override to Off exited the menus and Alt mode and turned the camera off.  I restarted in Canon mode and took 2 pictures (same scene, same zoom, same settings in all cases described here), one at Canon Normal and one at Fine.

Turned the camera off and restarted in CHDK mode, left Quality Override at Off, and took another two pictures at Canon Fine and Normal.  The results were (MBs):

CHDK mode:
Fine - 2.1
Normal - 1.2

Canon mode:
Fine - 2.7
Normal - 1.2
It seems to prove that even fine mode is impacted.

Re: SX230 1.01A CHDK .jpg files too small
« Reply #19 on: 01 / April / 2013, 09:37:12 »
I did make a feeble attempt to do this by putting that statement into a txt file, naming it with a .lua extension and putting it in the Scripts folder in CHDK.  I ran it from the Alt menu and it reported:

***Started***
:1: attempt to index a boolean value
Works for me using CHDK 1.2 (available from here: http://mighty-hoernsche.de/trunk/ ).
Make sure that the text editor you're using saves clean ASCII files, not unicode/UTF-8/... .


Using the CHDK version you suggested it reported: 335448

What does that tell us?

Thanks again,

 

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