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Date: Thu, 21 Mar 2024 13:49:26 +0100
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To: Changhuang Liang <changhuang.liang@starfivetech.com>,
 Mauro Carvalho Chehab <mchehab@kernel.org>,
 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
 Jack Zhu <jack.zhu@starfivetech.com>,
 "linux-media@vger.kernel.org" <linux-media@vger.kernel.org>,
 "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
 "linux-staging@lists.linux.dev" <linux-staging@lists.linux.dev>
References: <20240301070025.11144-1-changhuang.liang@starfivetech.com>
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From: Hans Verkuil <hverkuil-cisco@xs4all.nl>
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On 21/03/2024 1:17 pm, Changhuang Liang wrote:
> Hi, Hans
> 
> Thanks for your comments.
> 
>> On 01/03/2024 8:00 am, Changhuang Liang wrote:
>>> The pixel formats captured by the capture_raw video device depends on
>>> what pixel formats come from the source device. It is actually dump
>>> the source device data. So renamed it to capture_dump.
>>
>> I don't think 'dump' is a great name. I think what you really want to say is
>> 'unprocessed'. And usually that is indeed called 'raw capture'.
>>
> 
> StarFive JH7110 SoC also supports the output of the raw format data from ISP port, see:
> 
> https://lore.kernel.org/all/20240306093334.9321-1-changhuang.liang@starfivetech.com/
> 
> So I think it is better to call the ISP output port "capture_raw".

If it is processed by the ISP, how can it be 'raw'? Or do you mean that this uses Bayer pixelformat?

The normal convention AFAIK is that the term 'raw capture' generally means that
the sensor bayer data is captured without being processed (or only minimal processing).

Looking at:

https://lore.kernel.org/all/20240306093334.9321-6-changhuang.liang@starfivetech.com/

I think you indeed mean that you can get the processed ISP data in bayer format
through a separate video device. So I would call that port 'capture_bayer' and keep the
'capture_raw' name for the port from the CSI receiver.

Regards,

	Hans

> 
> On the other hand, Old "capture_raw" video devices can also support YUV color space, 
> mainly depending on the camera output format. There may be a confusion called it "capture_raw".
> 
> Regards,
> Changhuang
> 
>