Re: Getting started with OMAP3 ISP

[Gary Thomas <gary@mlbassoc.com>]

On 2011-09-01 12:14, Laurent Pinchart wrote:
> Hi Enrico,
>
> On Thursday 01 September 2011 19:24:54 Enrico wrote:
>> On Thu, Sep 1, 2011 at 6:14 PM, Enrico<ebutera@users.berlios.de>  wrote:
>>> On Thu, Sep 1, 2011 at 5:16 PM, Gary Thomas<gary@mlbassoc.com>  wrote:
>>>> - entity 16: tvp5150m1 2-005c (1 pad, 1 link)
>>>>              type V4L2 subdev subtype Unknown
>>>>              device node name /dev/v4l-subdev8
>>>>         pad0: Output [unknown 720x480 (1,1)/720x480]
>>>>                 ->  'OMAP3 ISP CCDC':pad0 [ACTIVE]
>>>>
>>>> Ideas where to look for the 'unknown' mode?
>>>
>>> I didn't notice that, if you are using UYVY8_2X8 the reason is in
>>> media-ctl main.c:
>>>
>>> { "UYVY", V4L2_MBUS_FMT_UYVY8_1X16 },
>>>
>>> You can add a line like:
>>>
>>> { "UYVY2X8", V4L2_MBUS_FMT_UYVY8_2X8 },
>>>
>>> recompile and it should work, i'll try it now.
>>
>> That worked, but now there is another problem.
>
> That's correct. My bad for not spotting it sooner.

Will you be adding this to the media-ctl tree?  Would you like a patch?

>
>> yavta will set UYVY (PIX_FMT), this will cause a call to
>> ispvideo.c:isp_video_pix_to_mbus(..), that will do this:
>>
>> for (i = 0; i<  ARRAY_SIZE(formats); ++i) {
>>                  if (formats[i].pixelformat == pix->pixelformat)
>>                          break;
>> }
>>
>> that is it will stop at the first matching array item, and that's:
>>
>> { V4L2_MBUS_FMT_UYVY8_1X16, V4L2_MBUS_FMT_UYVY8_1X16,
>>            V4L2_MBUS_FMT_UYVY8_1X16, 0,
>>            V4L2_PIX_FMT_UYVY, 16, 16, },
>>
>>
>> but you wanted this:
>>
>> { V4L2_MBUS_FMT_UYVY8_2X8, V4L2_MBUS_FMT_UYVY8_2X8,
>>            V4L2_MBUS_FMT_UYVY8_2X8, 0,
>>            V4L2_PIX_FMT_UYVY, 8, 16, },
>>
>> so a better check could be to check for width too, but i don't know if
>> it's possibile to pass a width requirement or if it's already there in
>> some struct passed to the function.
>
> That's not really an issue, as the isp_video_pix_to_mbus() and
> isp_video_mbus_to_pix() calls in isp_video_set_format() are just used to fill
> the bytesperline and sizeimage fields. From a quick look at the code
> isp_video_check_format() should succeed as well.
>
> Have you run into any specific issue with isp_video_pix_to_mbus() when using
> V4L2_MBUS_FMT_UYVY8_2X8 ?
>

Not yet - I was able to configure the pipeline as
   # media-ctl -f '"tvp5150m1 2-005c":0[UYVY2X8 720x480], "OMAP3 ISP CCDC":0[UYVY2X8 720x480], "OMAP3 ISP CCDC":1[UYVY2X8 720x480]'
and this gets me all the way into my driver (which I'm now working on)

-- 
------------------------------------------------------------
Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
------------------------------------------------------------