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Message-ID: <dbfebef8-89e6-c2e1-e81a-57640f6764e7@aspeedtech.com>
Date:   Mon, 17 Jan 2022 17:37:41 +0800
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Subject: Re: [PATCH v8 1/4] media: v4l: Add definition for the Aspeed JPEG
 format
Content-Language: en-US
To:     Hans Verkuil <hverkuil-cisco@xs4all.nl>,
        Joel Stanley <joel@jms.id.au>
CC:     "sakari.ailus@linux.intel.com" <sakari.ailus@linux.intel.com>,
        "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
        "eajames@linux.ibm.com" <eajames@linux.ibm.com>,
        "mchehab@kernel.org" <mchehab@kernel.org>,
        "andrew@aj.id.au" <andrew@aj.id.au>,
        "linux-media@vger.kernel.org" <linux-media@vger.kernel.org>,
        "openbmc@lists.ozlabs.org" <openbmc@lists.ozlabs.org>,
        "linux-arm-kernel@lists.infradead.org" 
        <linux-arm-kernel@lists.infradead.org>,
        "linux-aspeed@lists.ozlabs.org" <linux-aspeed@lists.ozlabs.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
References: <20211224012738.1551-1-jammy_huang@aspeedtech.com>
 <20211224012738.1551-2-jammy_huang@aspeedtech.com>
 <703ff71e-c76a-9df1-c644-04efed0199ca@xs4all.nl>
 <609cfe9e-2fd8-b31a-9d71-b83d61693f84@aspeedtech.com>
 <CACPK8XeJQHLWfVbBjArxV_QMDDnRXfccOeXdsn6aBEG7gd8yvw@mail.gmail.com>
 <98096e97-68cc-18fd-d2b6-3477f57f05bd@aspeedtech.com>
 <d4ccf803-3736-d95d-19a9-f3593465b81e@xs4all.nl>
From:   Jammy Huang <jammy_huang@aspeedtech.com>
In-Reply-To: <d4ccf803-3736-d95d-19a9-f3593465b81e@xs4all.nl>
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Hi Hans,

On 2022/1/17 下午 05:28, Hans Verkuil wrote:
> Hi Jammy,
>
> On 1/17/22 08:18, Jammy Huang wrote:
>> On 2022/1/17 上午 10:24, Joel Stanley wrote:
>>> On Mon, 17 Jan 2022 at 02:00, Jammy Huang <jammy_huang@aspeedtech.com> wrote:
>>>> Hi Hans,
>>>>
>>>> On 2022/1/14 下午 04:11, Hans Verkuil wrote:
>>>>> On 24/12/2021 02:27, Jammy Huang wrote:
>>>>>> This introduces support for the Aspeed JPEG format, where the new frame
>>>>>> can refer to previous frame to reduce the amount of compressed data. The
>>>>>> concept is similar to I/P frame of video compression. It will compare the
>>>>>> new frame with previous one to decide which macroblock's data is
>>>>>> changed, and only the changed macroblocks will be compressed.
>>>>>>
>>>>>> This Aspeed JPEG format is used by the video engine on Aspeed platforms,
>>>>>> which is generally adapted for remote KVM.
>>>>>>
>>>>>> Signed-off-by: Jammy Huang <jammy_huang@aspeedtech.com>
>>>>>> ---
>>>>>> v8:
>>>>>>      - Add decoder information for aspeed-jpeg
>>>>>> v7:
>>>>>>      - Add more information for aspeed-jpeg
>>>>>> v6:
>>>>>>      - Update description for new format, aspeed-jpeg, in Documentation.
>>>>>> v5:
>>>>>>      - no update
>>>>>> v4:
>>>>>>      - new
>>>>>> ---
>>>>>>     .../media/uapi/v4l/pixfmt-reserved.rst          | 17 +++++++++++++++++
>>>>>>     drivers/media/v4l2-core/v4l2-ioctl.c            |  1 +
>>>>>>     include/uapi/linux/videodev2.h                  |  1 +
>>>>>>     3 files changed, 19 insertions(+)
>>>>>>
>>>>>> diff --git a/Documentation/media/uapi/v4l/pixfmt-reserved.rst b/Documentation/media/uapi/v4l/pixfmt-reserved.rst
>>>>> This is the wrong file! It should be:
>>>>>
>>>>> Documentation/userspace-api/media/v4l/pixfmt-reserved.rst
>>>> Thanks, I just used git format-patch to generate the cover-letter and
>>>> didn't notice this.
>>>>
>>>> It looks like the file, pixfmt-reserved.rst, has different path in
>>>> different Linux kernel,
>>>>
>>>> * 5.4:           Documentation/media/uapi/v4l/pixfmt-reserved.rst
>>>>
>>>> * 5.10/5.15: Documentation/userspace-api/media/v4l/pixfmt-reserved.rst
>>>>
>>>> 5.4 is the one I based to submit the patches.
>>>>
>>>> Could you suggest the kernel that I should based to submit these patches??
>>> You should always submit based on the latest release.
>>>
>>> There are sometimes exceptions where you will base your patches on
>>> something even newer, but generally you should grab the latest.
>>>
>>> Be sure to re-test on the latest kernel before submitting.
>> OK, thank you.
> I recommend waiting until later this week. I hope to have a PR for other outstanding
> aspeed patches ready in a few days. It is easiest if you base your v9 on top of that
> series, this to avoid merge conflicts.

Sure, no problem. Thanks for your help.


Regards,

Jammy

>
> Regards,
>
> 	Hans
>
>>> Cheers,
>>>
>>> Joel
>>>
>>>> I will need to change the number of V4L2_CID_USER_ASPEED_BASE per different
>>>>
>>>> linux kernel as well.
>>>>
>>>>> Regards,
>>>>>
>>>>>         Hans
>>>>>
>>>>>> index b2cd155e691b..1d0dc8d86ed7 100644
>>>>>> --- a/Documentation/media/uapi/v4l/pixfmt-reserved.rst
>>>>>> +++ b/Documentation/media/uapi/v4l/pixfmt-reserved.rst
>>>>>> @@ -264,6 +264,23 @@ please make a proposal on the linux-media mailing list.
>>>>>>        of tiles, resulting in 32-aligned resolutions for the luminance plane
>>>>>>        and 16-aligned resolutions for the chrominance plane (with 2x2
>>>>>>        subsampling).
>>>>>> +    * .. _V4L2-PIX-FMT-AJPG:
>>>>>> +
>>>>>> +      - ``V4L2_PIX_FMT_AJPG``
>>>>>> +      - 'AJPG'
>>>>>> +      - ASPEED JPEG format used by the aspeed-video driver on Aspeed platforms,
>>>>>> +        which is generally adapted for remote KVM.
>>>>>> +        On each frame compression, I will compare the new frame with previous
>>>>>> +        one to decide which macroblock's data is changed, and only the changed
>>>>>> +        macroblocks will be compressed.
>>>>>> +
>>>>>> +        The implementation is based on AST2600 A3 datasheet, revision 0.9, which
>>>>>> +        is not publicly available. Or you can reference Video stream data format
>>>>>> +        – ASPEED mode compression of SDK_User_Guide which available on
>>>>>> +        AspeedTech-BMC/openbmc/releases.
>>>>>> +
>>>>>> +        Decoder's implementation can be found here,
>>>>>> +        `https://github.com/AspeedTech-BMC/aspeed_codec/ <https://github.com/AspeedTech-BMC/aspeed_codec/>`__
>>>>>>
>>>>>>     .. tabularcolumns:: |p{6.6cm}|p{2.2cm}|p{8.7cm}|
>>>>>>
>>>>>> diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
>>>>>> index 24db33f803c0..00dde01d2f97 100644
>>>>>> --- a/drivers/media/v4l2-core/v4l2-ioctl.c
>>>>>> +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
>>>>>> @@ -1378,6 +1378,7 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
>>>>>>                case V4L2_PIX_FMT_S5C_UYVY_JPG: descr = "S5C73MX interleaved UYVY/JPEG"; break;
>>>>>>                case V4L2_PIX_FMT_MT21C:        descr = "Mediatek Compressed Format"; break;
>>>>>>                case V4L2_PIX_FMT_SUNXI_TILED_NV12: descr = "Sunxi Tiled NV12 Format"; break;
>>>>>> +            case V4L2_PIX_FMT_AJPG:         descr = "Aspeed JPEG"; break;
>>>>>>                default:
>>>>>>                        if (fmt->description[0])
>>>>>>                                return;
>>>>>> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
>>>>>> index 3210b3c82a4a..994eb6155ea9 100644
>>>>>> --- a/include/uapi/linux/videodev2.h
>>>>>> +++ b/include/uapi/linux/videodev2.h
>>>>>> @@ -726,6 +726,7 @@ struct v4l2_pix_format {
>>>>>>     #define V4L2_PIX_FMT_INZI     v4l2_fourcc('I', 'N', 'Z', 'I') /* Intel Planar Greyscale 10-bit and Depth 16-bit */
>>>>>>     #define V4L2_PIX_FMT_SUNXI_TILED_NV12 v4l2_fourcc('S', 'T', '1', '2') /* Sunxi Tiled NV12 Format */
>>>>>>     #define V4L2_PIX_FMT_CNF4     v4l2_fourcc('C', 'N', 'F', '4') /* Intel 4-bit packed depth confidence information */
>>>>>> +#define V4L2_PIX_FMT_AJPG     v4l2_fourcc('A', 'J', 'P', 'G') /* Aspeed JPEG */
>>>>>>
>>>>>>     /* 10bit raw bayer packed, 32 bytes for every 25 pixels, last LSB 6 bits unused */
>>>>>>     #define V4L2_PIX_FMT_IPU3_SBGGR10  v4l2_fourcc('i', 'p', '3', 'b') /* IPU3 packed 10-bit BGGR bayer */
>>>> -- 
>>>> Best Regards
>>>> Jammy
>>>>