Re: [RFC v4 7/8] media: vivid: Add support to the CSC API

[Hans Verkuil <hverkuil@xs4all.nl>]

On 05/06/2020 19:26, Dafna Hirschfeld wrote:
> The CSC API (Colorspace conversion) allows userspace to try
> to configure the ycbcr/hsv_enc function and the quantization
> for capture devices. This patch adds support to the CSC API
> in vivid.
> Using the CSC API, userspace is allowed to do the following:
> 
> 1. Set the ycbcr_enc function for YUV formats.
> 2. Set the hsv_enc function for HSV formats
> 3. Set the quantization for YUV and RGB formats.

I just realized something. We excluded colorspace and xfer_func from the CSC API
for now since there are no drivers that support those conversions. But actually,
that's not true since vivid *does* support this unless it is in loopback mode
(then no CSC conversion is supported).

So if dev->loop_video is true, then disable CSC conversion in vivid.

Otherwise CSC can be fully enabled for all four colorimetry fields.

So I think we should add flags to signal this for colorspace and xfer_func as well
and implement this in vivid.

Sorry about this, I should have realized this (much) earlier.

Regards,

	Hans

> 
> Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
> ---
>  .../media/test-drivers/vivid/vivid-vid-cap.c  | 49 +++++++++++++++++--
>  .../test-drivers/vivid/vivid-vid-common.c     | 20 ++++++++
>  2 files changed, 65 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/media/test-drivers/vivid/vivid-vid-cap.c b/drivers/media/test-drivers/vivid/vivid-vid-cap.c
> index e94beef008c8..8a43d7ebe53f 100644
> --- a/drivers/media/test-drivers/vivid/vivid-vid-cap.c
> +++ b/drivers/media/test-drivers/vivid/vivid-vid-cap.c
> @@ -549,6 +549,29 @@ int vivid_g_fmt_vid_cap(struct file *file, void *priv,
>  	return 0;
>  }
>  
> +static bool vivid_is_hsv_enc_valid(__u8 hsv_enc)
> +{
> +	if (hsv_enc == V4L2_HSV_ENC_180 || hsv_enc == V4L2_HSV_ENC_256)
> +		return true;
> +	return false;
> +}
> +
> +static bool vivid_is_ycbcr_enc_valid(__u8 ycbcr_enc)
> +{
> +	/* V4L2_YCBCR_ENC_SMPTE240M is the last ycbcr_enc enum */
> +	if (ycbcr_enc && ycbcr_enc <= V4L2_YCBCR_ENC_SMPTE240M)
> +		return true;
> +	return false;
> +}
> +
> +static bool vivid_is_quant_valid(__u8 quantization)
> +{
> +	if (quantization == V4L2_QUANTIZATION_FULL_RANGE ||
> +	    quantization == V4L2_QUANTIZATION_LIM_RANGE)
> +		return true;
> +	return false;
> +}
> +
>  int vivid_try_fmt_vid_cap(struct file *file, void *priv,
>  			struct v4l2_format *f)
>  {
> @@ -560,6 +583,7 @@ int vivid_try_fmt_vid_cap(struct file *file, void *priv,
>  	unsigned factor = 1;
>  	unsigned w, h;
>  	unsigned p;
> +	bool user_set_csc = !!(mp->flags & V4L2_PIX_FMT_FLAG_SET_CSC);
>  
>  	fmt = vivid_get_format(dev, mp->pixelformat);
>  	if (!fmt) {
> @@ -634,12 +658,23 @@ int vivid_try_fmt_vid_cap(struct file *file, void *priv,
>  			(fmt->bit_depth[0] / fmt->vdownsampling[0]);
>  
>  	mp->colorspace = vivid_colorspace_cap(dev);
> -	if (fmt->color_enc == TGP_COLOR_ENC_HSV)
> -		mp->hsv_enc = vivid_hsv_enc_cap(dev);
> -	else
> +	if (fmt->color_enc == TGP_COLOR_ENC_HSV) {
> +		if (!user_set_csc || !vivid_is_hsv_enc_valid(mp->hsv_enc))
> +			mp->hsv_enc = vivid_hsv_enc_cap(dev);
> +	} else if (fmt->color_enc == TGP_COLOR_ENC_YCBCR) {
> +		if (!user_set_csc || !vivid_is_ycbcr_enc_valid(mp->ycbcr_enc))
> +			mp->ycbcr_enc = vivid_ycbcr_enc_cap(dev);
> +	} else {
>  		mp->ycbcr_enc = vivid_ycbcr_enc_cap(dev);
> +	}
>  	mp->xfer_func = vivid_xfer_func_cap(dev);
> -	mp->quantization = vivid_quantization_cap(dev);
> +	if (fmt->color_enc == TGP_COLOR_ENC_YCBCR ||
> +	    fmt->color_enc == TGP_COLOR_ENC_RGB) {
> +		if (!user_set_csc || !vivid_is_quant_valid(mp->quantization))
> +			mp->quantization = vivid_quantization_cap(dev);
> +	} else {
> +		mp->quantization = vivid_quantization_cap(dev);
> +	}
>  	memset(mp->reserved, 0, sizeof(mp->reserved));
>  	return 0;
>  }
> @@ -769,6 +804,12 @@ int vivid_s_fmt_vid_cap(struct file *file, void *priv,
>  	if (vivid_is_sdtv_cap(dev))
>  		dev->tv_field_cap = mp->field;
>  	tpg_update_mv_step(&dev->tpg);
> +	dev->tpg.quantization = mp->quantization;
> +	if (dev->fmt_cap->color_enc == TGP_COLOR_ENC_YCBCR)
> +		dev->tpg.ycbcr_enc = mp->ycbcr_enc;
> +	else
> +		dev->tpg.hsv_enc = mp->hsv_enc;
> +
>  	return 0;
>  }
>  
> diff --git a/drivers/media/test-drivers/vivid/vivid-vid-common.c b/drivers/media/test-drivers/vivid/vivid-vid-common.c
> index 76b0be670ebb..19aacb180e67 100644
> --- a/drivers/media/test-drivers/vivid/vivid-vid-common.c
> +++ b/drivers/media/test-drivers/vivid/vivid-vid-common.c
> @@ -920,6 +920,26 @@ int vivid_enum_fmt_vid(struct file *file, void  *priv,
>  	fmt = &vivid_formats[f->index];
>  
>  	f->pixelformat = fmt->fourcc;
> +
> +	if (f->type != V4L2_BUF_TYPE_VIDEO_CAPTURE &&
> +	    f->type != V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE)
> +		return 0;
> +	/*
> +	 * For capture devices, we support the CSC API.
> +	 * We allow userspace to:
> +	 * 1. set the ycbcr_enc on yuv format
> +	 * 2. set the hsv_enc on hsv format
> +	 * 3. set the quantization on yuv and rgb formats
> +	 */
> +	if (fmt->color_enc == TGP_COLOR_ENC_YCBCR) {
> +		f->flags |= V4L2_FMT_FLAG_CSC_YCBCR_ENC;
> +		f->flags |= V4L2_FMT_FLAG_CSC_QUANTIZATION;
> +	} else if (fmt->color_enc == TGP_COLOR_ENC_HSV) {
> +		f->flags |= V4L2_FMT_FLAG_CSC_HSV_ENC;
> +	} else if (fmt->color_enc == TGP_COLOR_ENC_RGB) {
> +		f->flags |= V4L2_FMT_FLAG_CSC_QUANTIZATION;
> +	}
> +
>  	return 0;
>  }
>  
>