Re: [PATCH v3] media: usb: uvc: Add UVC_GUID_FORMAT_H265

From: Ricardo Ribalda <ribalda@chromium.org>
To: James_Lin <Ping-lei.Lin@mediatek.com>
Cc: linux-kernel@vger.kernel.org,
	 Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
	 Mauro Carvalho Chehab <mchehab@kernel.org>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	 Hans Verkuil <hverkuil-cisco@xs4all.nl>,
	Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>,
	 Arnd Bergmann <arnd@arndb.de>,
	Sergey Senozhatsky <senozhatsky@chromium.org>,
	 Alexandre Courbot <acourbot@chromium.org>,
	Sakari Ailus <sakari.ailus@linux.intel.com>,
	 linux-media@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	 linux-mediatek@lists.infradead.org, sherlock.chang@mediatek.com,
	 lecopzer.chen@mediatek.com, max.yan@mediatek.com,
	tm.wu@mediatek.com
Subject: Re: [PATCH v3] media: usb: uvc: Add UVC_GUID_FORMAT_H265
Date: Tue, 19 Apr 2022 13:46:15 +0200	[thread overview]
Message-ID: <CANiDSCvLb785H7qyAzSfTSBRpO2eM-oJFF5SgVHXdL1O-GusLA@mail.gmail.com> (raw)
In-Reply-To: <20220418090652.3156-1-Ping-lei.Lin@mediatek.com>

Hi James

Thanks for your patch

On Mon, 18 Apr 2022 at 11:07, James_Lin <Ping-lei.Lin@mediatek.com> wrote:
>
> This patch aims to add UVC_GUID_FORMAT_H265
> High Efficiency Video Coding (HEVC), also known as H.265 and MPEG-H Part 2.
> They describe the same video encoding method.
> So for handling their behavior is the same.
> However, when external camera device describes this encoding method,
> some use hevc, some use h265.
> There is no uniform specification to describe this encoding method.
> So if an external camera device use h265 to describe this encoding method,
> driver will not recognize it.
> Therefore, this patch is to enable driver to read HEVC/H265
> and convert it to V4L2_PIX_FMT_HEVC.
>
> Signed-off-by: James_Lin <Ping-lei.Lin@mediatek.com>

Reviewed-by: Ricardo Ribalda <ribalda@chromium.org>

> ---
>  drivers/media/usb/uvc/uvc_driver.c | 5 +++++
>  drivers/media/usb/uvc/uvcvideo.h   | 3 +++
>  2 files changed, 8 insertions(+)
>
> diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
> index dda0f0aa78b8..e437e9f95890 100644
> --- a/drivers/media/usb/uvc/uvc_driver.c
> +++ b/drivers/media/usb/uvc/uvc_driver.c
> @@ -154,6 +154,11 @@ static struct uvc_format_desc uvc_fmts[] = {
>                 .guid           = UVC_GUID_FORMAT_H264,
>                 .fcc            = V4L2_PIX_FMT_H264,
>         },

Maybe I would add a comment here saying that some cameras represent
hevc as h265.

> +       {
> +               .name           = "H.265",
> +               .guid           = UVC_GUID_FORMAT_H265,
> +               .fcc            = V4L2_PIX_FMT_HEVC,
> +       },
>         {
>                 .name           = "Greyscale 8 L/R (Y8I)",
>                 .guid           = UVC_GUID_FORMAT_Y8I,
> diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
> index 143230b3275b..41f4d8c33f2a 100644
> --- a/drivers/media/usb/uvc/uvcvideo.h
> +++ b/drivers/media/usb/uvc/uvcvideo.h
> @@ -139,6 +139,9 @@
>  #define UVC_GUID_FORMAT_H264 \
>         { 'H',  '2',  '6',  '4', 0x00, 0x00, 0x10, 0x00, \
>          0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
> +#define UVC_GUID_FORMAT_H265 \
> +       { 'H',  '2',  '6',  '5', 0x00, 0x00, 0x10, 0x00, \
> +        0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
>  #define UVC_GUID_FORMAT_Y8I \
>         { 'Y',  '8',  'I',  ' ', 0x00, 0x00, 0x10, 0x00, \
>          0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
> --
> 2.18.0
>

-- 
Ricardo Ribalda

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