Re: libv4l: Possibility of changing the current pixelformat on the fly

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2009/4/5 Jean-Francois Moine <moinejf@xxxxxxx>:
> On Sat, 04 Apr 2009 22:22:19 +0200
> Erik Andrén <erik.andren@xxxxxxxxx> wrote:
>        [snip]
>> When flipping the image horizontally, vertically or both, the sensor
>> pixel ordering changes. In the m5602 driver I was able to compensate
>> for this in the bridge code. In the stv06xx I don't have this
>> option. One way of solving this problem is by changing the
>> pixelformat on the fly, i. e V4L2_PIX_FMT_SGRB8 is the normal
>> format. When a vertical flip is required, change the format to
>> V4L2_SBGGR8.
>>
>> My current understanding of libv4l is that it probes the pixelformat
>>   upon device open. In order for this to work we would need either
>> poll the current pixelformat regularly or implement some kind of
>> notification mechanism upon a flipping request.
>>
>> What do you think is this the right way to go or is there another
>> alternative.
>
> Hi Erik,
>
> I saw such a problem in some other webcams. When doing a flip, the
> sensor scans the pixels in the reverse order. So,
>        R G R G
>        G B G B
> becomes
>        B G B G
>        G R G R
>
> The solution is to start the scan one line lower or higher for VFLIP
> and one pixel on the left or on the right for HFLIP.
>

As I wrote in my original email I haven't found out a way to adjust
this when using the vv6410 sensor.

> May you do this with all the sensors of the stv06xx?

This issue is vv6410 specific.

Best regards,
Erik Andrén

>
> Cheers.
>
> --
> Ken ar c'hentan |             ** Breizh ha Linux atav! **
> Jef             |               http://moinejf.free.fr/
>
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