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

[Dafna Hirschfeld <dafna.hirschfeld@xxxxxxxxxxxxx>]

On 08.06.20 12:10, Hans Verkuil wrote:
> 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).

But shouldn't there be at least one real hardware device that support it in order
to justify it in the API?

Thanks,
Dafna

> 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@xxxxxxxxxxxxx>
> > ---
> >   .../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;
> >   }
> >