Re: AW: mt9p031 shows purple coloured capture

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Florian,

On Friday 21 June 2013 15:23:53 Florian Neuhaus wrote:
> Laurent Pinchart wrote on 2013-06-18:
> >> If I use omap3isp-live to capture a stream on my beagleboard, the first
> >> time I start the app, the picture has always a green taint. The second
> >> time I start the app, the picture is good. As the camera is reset by a
> >> gpio upon device open, probably the CCDC or previewer is not
> >> initialized correctly? @Laurent: As I am unable to test it with another
> >> cam, does this also happen with your hardware or is it a problem
> >> specific to the mt9p031?
> > 
> > Last time I've tested my MT9P031 sensor with the Beagleboard-xM there
> > was no such issue.
> 
> If I test it with yavta, it works also from the very first start. So there
> must be an issue in my (adapted) omap3-isp-live.

Have you tested the unmodified omap3-is-live ?

> >> The second problem is similiar to your problem:
> >> omap3isp-live has (thanks to Laurent) a built in snapshot-mode. So I
> >> am doing the following:
> >> 1. Streaming video, picture looks good on the second start 2. Taking a
> >> snapshot: The video stream will turn off, the isp-pipe reconfigured.
> >> Then the stream will be turned back on and the captured image will be
> >> written to memory.
> >> 3. The captured image will now be displayed, but the image is corrupted:
> >> Wrong colors and cut in half:
> >> https://www.dropbox.com/s/ijk1nq8nrhlobfd/bad-snapshot.jpg
> >> 4. It doesn't help to skip a few buffers, also the 3rd buffer looks bad.
> >> 5. Additional problem: The CCDC can't be stopped properly (omap3isp
> >> omap3isp: Unable to stop OMAP3 ISP CCDC) and sometimes the isp locks
> >> up completely.
> >> 
> >>> So I used the register 0x0B (Restart), bit 0 (abandon the current
> >>> frame and restart from the first row) set to 1 each time the
> >>> function s_stream is called.
> >> 
> >> The finding so far: If I do a frame-restart (the register 0x0b on
> >> mt9p031) upon stream-on, the CCDC can be stopped properly and the
> >> snapshot looks pretty good. BUT the colors are still messed up. If I
> >> then switch to streaming again, the colors sometimes turn to good but
> >> sometimes the picture is purple tainted. @Andrei: What have you done to
> >> get good colors?
> 
> The color problem goes away nearly completely, if I do a power-off and on in
> the mt9p031_s_stream function. It then happens only 1 out of 10 times. At
> least an improvement ;)
> I have the feeling, that the CCDC doesn't get all data on a stream restart
> and that causes a buffer corruption. Probably the sensor doesn't start
> outputting from the beginning (even with a frame restart).
> Any ideas on this?

-- 
Regards,

Laurent Pinchart