Re: [alsa-devel] [PATCH v5 4/6] media: i2c: Add TDA1997x HDMI receiver driver

19 Dec 2017


      On Tue, Dec 19, 2017 at 3:12 AM, Hans Verkuil hverkuil@xs4all.nl wrote:
...
On 16/12/17 19:00, Tim Harvey wrote:
...


+static int tda1997x_fill_format(struct tda1997x_state *state,

                        struct v4l2_mbus_framefmt *format)


+{

const struct v4l2_bt_timings *bt;


struct v4l2_hdmi_colorimetry c;


v4l_dbg(1, debug, state->client, "%s\n", __func__);


if (!state->detected_timings)


        return -EINVAL;


bt = &state->detected_timings->bt;


memset(format, 0, sizeof(*format));


c = v4l2_hdmi_rx_colorimetry(&state->avi_infoframe, NULL, bt->height);


format->width = bt->width;


format->height = bt->height;


format->field = (bt->interlaced) ?


        V4L2_FIELD_ALTERNATE : V4L2_FIELD_NONE;


format->colorspace = c.colorspace;


format->ycbcr_enc = c.ycbcr_enc;


format->quantization = c.quantization;


format->xfer_func = c.xfer_func;


This is wrong. v4l2_hdmi_rx_colorimetry returns what arrives on the HDMI link,
that's not the same as is output towards the SoC. You need to take limited/full
range conversions and 601/709 conversions into account since that's what ends
up in memory.
Also note: you are still parsing the colorimetry information from avi_infoframe
in the infoframe parse function. There is no need to do that, just call
v4l2_hdmi_rx_colorimetry and let that function parse and interpret all this.
Otherwise we still have two places that try to interpret that information.
Hans,
Ok so v4l2_hdmi_rx_colorimetry() handles parsing the source avi
infoframe and deals with enforcing the detailed rules and returns
'v4l2' enums:
tda1997x_parse_infoframe(...)
...
        case HDMI_INFOFRAME_TYPE_AVI:
                state->avi_infoframe = frame.avi; /* hold on to avi
infoframe for later use in logging etc */
                /* parse avi infoframe colorimetry data for v4l2
colorspace/ycbcr_encoding/quantization/xfer_func */
                state->hdmi_colorimetry = v4l2_hdmi_rx_colorimetry(&frame.avi,
                                                NULL,
                                                state->timings.bt.height);
Also here I still need to override the quant range passed from the
source avi infoframe per the user control (if not auto) and set per
vic if default:
/* Quantization Range */
                switch (state->rgb_quantization_range) {
                case V4L2_DV_RGB_RANGE_AUTO:
                        state->range = frame.avi.quantization_range;
                        break;
                case V4L2_DV_RGB_RANGE_LIMITED:
                        state->range = HDMI_QUANTIZATION_RANGE_LIMITED;
                        break;
                case V4L2_DV_RGB_RANGE_FULL:
                        state->range = HDMI_QUANTIZATION_RANGE_FULL;
                        break;
                }
                if (state->range == HDMI_QUANTIZATION_RANGE_DEFAULT) {
                        if (frame.avi.video_code <= 1)
                                state->range = HDMI_QUANTIZATION_RANGE_FULL;
                        else
                                state->range = HDMI_QUANTIZATION_RANGE_LIMITED;
                }
Then tda1997x_fill_format() then needs to fill in details of what's on
the bus so I should be filling in only width/height/field/colorspace
and use colorspace based on my csc conversion chosen output
(V4L2_COLORSPACE_SRGB|V4L2_COLORSPACE_SMPTE170M|V4L2_COLORSPACE_REC709)
and I don't need to set ycbcr_enc/quantization/xfer_func.
does this sound right?
Thanks,
Tim