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From: Hans Verkuil <hverkuil@xs4all.nl>
To: Steve Longerbeam <slongerbeam@gmail.com>, linux-media@vger.kernel.org
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
	Rui Miguel Silva <rmfrfs@gmail.com>,
	Philipp Zabel <p.zabel@pengutronix.de>
Subject: Re: [PATCH] media: imx: utils: Default colorspace to SRGB
Date: Thu, 16 Apr 2020 12:52:57 +0200	[thread overview]
Message-ID: <9cea8cb9-b127-6ff0-a240-be338e081eaa@xs4all.nl> (raw)
In-Reply-To: <20200325173456.21455-1-slongerbeam@gmail.com>

Hi Steve,

On 25/03/2020 18:34, Steve Longerbeam wrote:
> The function init_mbus_colorimetry() is used to initialize the imx
> subdevice mbus colorimetry to some sane defaults when the subdevice is
> registered. Currently it guesses at a colorspace based on the passed
> mbus pixel format. If the format is RGB, it chooses colorspace
> V4L2_COLORSPACE_SRGB, and if the format is YUV, it chooses
> V4L2_COLORSPACE_SMPTE170M.
> 
> While that might be a good guess, it's not necessarily true that a RGB
> pixel format encoding uses a SRGB colorspace, or that a YUV encoding
> uses a SMPTE170M colorspace. Instead of making this dubious guess,
> just default the colorspace to SRGB.
> 
> Reported-by: Hans Verkuil <hverkuil@xs4all.nl>
> Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
> ---
>  drivers/staging/media/imx/imx-media-utils.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/staging/media/imx/imx-media-utils.c b/drivers/staging/media/imx/imx-media-utils.c
> index fae981698c49..8344675bfd05 100644
> --- a/drivers/staging/media/imx/imx-media-utils.c
> +++ b/drivers/staging/media/imx/imx-media-utils.c
> @@ -236,8 +236,7 @@ static const struct imx_media_pixfmt ipu_rgb_formats[] = {
>  static void init_mbus_colorimetry(struct v4l2_mbus_framefmt *mbus,
>  				  const struct imx_media_pixfmt *fmt)
>  {
> -	mbus->colorspace = (fmt->cs == IPUV3_COLORSPACE_RGB) ?
> -		V4L2_COLORSPACE_SRGB : V4L2_COLORSPACE_SMPTE170M;
> +	mbus->colorspace = V4L2_COLORSPACE_SRGB;
>  	mbus->xfer_func = V4L2_MAP_XFER_FUNC_DEFAULT(mbus->colorspace);
>  	mbus->ycbcr_enc = V4L2_MAP_YCBCR_ENC_DEFAULT(mbus->colorspace);
>  	mbus->quantization =

The quantization is probably wrong as well since it checks fmt->cs.
The first argument should just be 'true'.

> 

In any case, this patch no longer applies after the imx utils patch series.

Regards,

	Hans

  reply	other threads:[~2020-04-16 11:42 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-25 17:34 [PATCH] media: imx: utils: Default colorspace to SRGB Steve Longerbeam
2020-04-16 10:52 ` Hans Verkuil [this message]
2020-04-16 17:10   ` Steve Longerbeam
2020-04-17  7:13     ` Hans Verkuil

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