Hi Hans,
Thanks for your comments and feedback!
From: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
Date: qua, jun 02, 2021 at 13:34:53
> On 02/06/2021 13:24, Nelson Costa wrote:
> > This adds support to get aspect ratio for the current
> > video being received and provide the info through v4l2
> > API query_dv_timings.
> >
> > Signed-off-by: Nelson Costa <nelson.costa@xxxxxxxxxxxx>
> > ---
> > drivers/media/platform/dwc/dw-hdmi-rx.c | 54 +++++++++++++++++++++++++++++++--
> > 1 file changed, 52 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/media/platform/dwc/dw-hdmi-rx.c b/drivers/media/platform/dwc/dw-hdmi-rx.c
> > index b20eccc..a468a93 100644
> > --- a/drivers/media/platform/dwc/dw-hdmi-rx.c
> > +++ b/drivers/media/platform/dwc/dw-hdmi-rx.c
> > @@ -2250,13 +2250,31 @@ static u32 dw_hdmi_get_width(struct dw_hdmi_dev *dw_dev)
> > return width;
> > }
> >
> > +static int dw_hdmi_vic_to_cea861(u8 hdmi_vic)
> > +{
> > + switch (hdmi_vic) {
> > + case 1:
> > + return 95;
> > + case 2:
> > + return 94;
> > + case 3:
> > + return 93;
> > + case 4:
> > + return 98;
> > + default:
> > + return 0;
> > + }
> > +}
>
> This should be in v4l2-dv-timings.c. It's a useful generic function.
>
I agree! I will make a specific patch for this in the next patch series.
> > +
> > static int dw_hdmi_query_dv_timings(struct v4l2_subdev *sd,
> > struct v4l2_dv_timings *timings)
> > {
> > struct dw_hdmi_dev *dw_dev = to_dw_dev(sd);
> > struct v4l2_bt_timings *bt = &timings->bt;
> > + struct v4l2_dv_timings t = {0};
>
> Use '= {}', it looks a bit nicer that way.
>
I agree!
> > bool is_hdmi_vic;
> > u32 htot, hofs;
> > + u8 cea861_vic;
> > u32 vtot;
> > u8 vic;
> >
> > @@ -2351,8 +2369,40 @@ static int dw_hdmi_query_dv_timings(struct v4l2_subdev *sd,
> > }
> > }
> >
> > - dev_dbg(dw_dev->dev, "%s: width=%u, height=%u, mbuscode=%u\n", __func__,
> > - bt->width, bt->height, dw_hdmi_get_mbus_code(dw_dev));
> > + if (is_hdmi_vic)
> > + cea861_vic = dw_hdmi_vic_to_cea861(bt->hdmi_vic);
> > + else
> > + cea861_vic = vic;
>
> This definitely is needed, but note that this is unrelated to the Aspect Ratio
> support. This should be done in a separate patch.
>
Ok.
> > +
> > + /* picture aspect ratio based on v4l2 dv timings array */
> > + if (v4l2_find_dv_timings_cea861_vic(&t, cea861_vic)) {
> > + /* when the numerator/denominator are zero means that the
> > + * picture aspect ratio is the same of the active measures ratio
> > + */
> > + if (!t.bt.picture_aspect.numerator) {
> > + unsigned long n, d;
> > +
> > + rational_best_approximation(t.bt.width, t.bt.height,
> > + t.bt.width, t.bt.height,
> > + &n, &d);
> > + t.bt.picture_aspect.numerator = n;
> > + t.bt.picture_aspect.denominator = d;
> > + }
> > +
> > + bt->picture_aspect = t.bt.picture_aspect;
>
> Why do this? picture_aspect is only used if it is non-square (V4L2_DV_FL_HAS_PICTURE_ASPECT
> is set), so there is no need to set it if V4L2_DV_FL_HAS_PICTURE_ASPECT is cleared.
>
> I don't see any reason for this.
>
I agree! That related part will be removed then, once for the square vics
it's
normal to have both "numerator == denominator == 0" and user space
applications
shall handle properly with that.
Thanks,
BR,
Nelson Costa
> Regards,
>
> Hans
>
> > + } else {
> > + bt->picture_aspect.numerator = 0;
> > + bt->picture_aspect.denominator = 0;
> > + dev_dbg(dw_dev->dev,
> > + "%s: cea861_vic=%d was not found in v4l2 dv timings",
> > + __func__, cea861_vic);
> > + }
> > +
> > + dev_dbg(dw_dev->dev,
> > + "%s: width=%u, height=%u, mbuscode=%u, cea861_vic=%d, ar={%d,%d}\n",
> > + __func__, bt->width, bt->height, dw_hdmi_get_mbus_code(dw_dev),
> > + cea861_vic, bt->picture_aspect.numerator,
> > + bt->picture_aspect.denominator);
> >
> > return 0;
> > }
> >
