Hot pixels (vertical line) to reduce in video capture - General Help and Assistance on using CHDK stable releases - CHDK Forum

Hot pixels (vertical line) to reduce in video capture

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Offline Lebeau

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Hot pixels (vertical line) to reduce in video capture
« on: 03 / December / 2010, 19:36:19 »
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I already modified the "raw.c" file to remove this "hot pixelized" defective vertical lines when catching RAW and JPG.

Now, I would like to find what file I shall change to remove this line from video capture.

 Thanks for CHDK ! I like, sorry, I love it.

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Online reyalp

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Re: Hot pixels (vertical line) to reduce in video capture
« Reply #1 on: 03 / December / 2010, 21:45:40 »
Maybe, maybe not. If you are reasonably proficient in reverse engineering, you may be able to figure it out. AFAIK, no one has modified the frames of in-camera video from CHDK yet.

First task is to find a buffer with the video before it is compressed, if such a thing is accessible to the ARM side of Digic.

If that is found, you may or may not be able to do the correction while keeping up with video frame rates.
Don't forget what the H stands for.

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Offline Lebeau

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Re: Hot pixels (vertical line) to reduce in video capture
« Reply #2 on: 04 / December / 2010, 11:04:19 »
Thanks reyalp for your encouragements.

I tought you already found that place. In reengineering, younger, i was excellent but now ...

I will give a guess to look how to huffyuv the LCD content (480x360). I know where it is, it is used in Motion Detection ! It's not 640x480 but may be I would reach a faster pace than 30 fps ?!

But if I find the video processing path ...

P.S.: I never quit ...

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Online reyalp

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Re: Hot pixels (vertical line) to reduce in video capture
« Reply #3 on: 04 / December / 2010, 17:45:54 »
Thanks reyalp for your encouragements.

I tought you already found that place. In reengineering, younger, i was excellent but now ...

I will give a guess to look how to huffyuv the LCD content (480x360). I know where it is, it is used in Motion Detection ! It's not 640x480 but may be I would reach a faster pace than 30 fps ?!

But if I find the video processing path ...

P.S.: I never quit ...
You could record uncompressed live view, but 30fps might be difficult. Some information on live view layout http://chdk.setepontos.com/index.php?topic=5415.0
Don't forget what the H stands for.


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Offline Lebeau

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Re: Hot pixels (vertical line) to reduce in video capture
« Reply #4 on: 11 / December / 2010, 10:47:57 »
I get a look to the suggested post and still asking a question.

What the difference between viewport and bitmap in, for exemple, "vid_get_viewport_fb" and "vid_get_bitmap_fb" ?

For video purpose, should viewport or bitmap get my attention? Or both?

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Online reyalp

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Re: Hot pixels (vertical line) to reduce in video capture
« Reply #5 on: 11 / December / 2010, 15:28:20 »
What the difference between viewport and bitmap in, for exemple, "vid_get_viewport_fb" and "vid_get_bitmap_fb" ?

For video purpose, should viewport or bitmap get my attention? Or both?
Viewport is the live view, in UYVYYY format. This shows the scene you see on the LCD.

Video recording may be available in another buffer somewhere before jpeg encoding, but this is unknown (to me at least)

bitmap is the UI overlay, which is 8 bit paletted, like original 256 color VGA.
Don't forget what the H stands for.

 

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