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Date:   Sun, 7 Jun 2020 04:07:19 +0300
From:   Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To:     Dmitry Buzdyk <dima.buzdyk@gmail.com>
Cc:     Mauro Carvalho Chehab <mchehab@kernel.org>,
        linux-media@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH] uvcvideo: Add mapping for HEVC payloads
Message-ID: <20200607010719.GU7339@pendragon.ideasonboard.com>
References: <20200529010547.GA630131@dmitry-T520>
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Hi Dmitry,

Thank you for the patch.

On Fri, May 29, 2020 at 11:05:47AM +1000, Dmitry Buzdyk wrote:
> Add HEVC GUID and assotiate with HEVC pixel format so that frame
> based format descriptors recognized by the UVC video driver.

The patch itself looks OK to me, but could you share a bit more
information about which device(s) implement this ? Are they UVC 1.1
devices ? Could you share their full USB descriptors (retrieved with
'lsusb -v', running as root if possible) ?

Is there anything else needed to get HEVC capture working, such as
extension unit controls, or is this patch enough ? What userspace
software do you use to capture and decode HEVC (or capture it to disk) ?

> Signed-off-by: Dmitry Buzdyk <dima.buzdyk@gmail.com>
> ---
>  drivers/media/usb/uvc/uvc_driver.c | 5 +++++
>  drivers/media/usb/uvc/uvcvideo.h   | 4 ++++
>  2 files changed, 9 insertions(+)
> 
> diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
> index 431d86e1c94b..825ee3601661 100644
> --- a/drivers/media/usb/uvc/uvc_driver.c
> +++ b/drivers/media/usb/uvc/uvc_driver.c
> @@ -214,6 +214,11 @@ static struct uvc_format_desc uvc_fmts[] = {
>  		.guid		= UVC_GUID_FORMAT_CNF4,
>  		.fcc		= V4L2_PIX_FMT_CNF4,
>  	},
> +	{
> +		.name		= "HEVC",
> +		.guid		= UVC_GUID_FORMAT_HEVC,
> +		.fcc		= V4L2_PIX_FMT_HEVC,
> +	},
>  };
>  
>  /* ------------------------------------------------------------------------
> diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
> index 6ab972c643e3..c7f043121b41 100644
> --- a/drivers/media/usb/uvc/uvcvideo.h
> +++ b/drivers/media/usb/uvc/uvcvideo.h
> @@ -165,6 +165,10 @@
>  	{0x32, 0x00, 0x00, 0x00, 0x02, 0x00, 0x10, 0x00, \
>  	 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
>  
> +#define UVC_GUID_FORMAT_HEVC \
> +	{ 'H',  'E',  'V',  'C', 0x00, 0x00, 0x10, 0x00, \
> +	 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
> +
>  
>  /* ------------------------------------------------------------------------
>   * Driver specific constants.

-- 
Regards,

Laurent Pinchart