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SubjectRe: [PATCH v5 4/6] media: i2c: Add TDA1997x HDMI receiver driver
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On 19/12/17 18:01, Tim Harvey wrote:
> 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;
> }

No, the vic check is already done in v4l2_hdmi_rx_colorimetry.

Call v4l2_hdmi_rx_colorimetry first, then:

/* If ycbcr_enc is V4L2_YCBCR_ENC_DEFAULT, then we receive RGB */
if (c.ycbcr_enc == V4L2_YCBCR_ENC_DEFAULT)
switch (state->rgb_quantization_range) {
case V4L2_DV_RGB_RANGE_LIMITED:
c.quantization = V4L2_QUANTIZATION_FULL_RANGE;
break;
case V4L2_DV_RGB_RANGE_FULL:
c.quantization = V4L2_QUANTIZATION_LIM_RANGE;
break;
}

(c is of type struct v4l2_hdmi_colorimetry)

>
>
> 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.

You don't touch the colorspace and xfer_func fields. The simple matrix
csc can only change quantization range and/or ycbcr encoding.

It doesn't change the underlying colorspace ('chromaticities') or the
used transfer function.

In practice if the output is RGB then ycbcr_enc should be set to
V4L2_YCBCR_ENC_DEFAULT and quantization to FULL_RANGE. For YUV output you
set ycbcr_enc to V4L2_YCBCR_ENC_601 or 709 and quantization to LIM_RANGE.

Regards,

Hans

>
> does this sound right?
>
> Thanks,
>
> Tim
>

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