On Mon, Oct 23, 2017 at 10:05 AM, Tim Harvey <tharvey@xxxxxxxxxxxxx> wrote:
>
> On Fri, Oct 20, 2017 at 9:23 AM, Hans Verkuil <hverkuil@xxxxxxxxx> wrote:
>
> >>
> >> I see the AVI infoframe has hdmi_quantization_range and
> >> hdmi_ycc_quantization_range along with vid_code.
> >>
> >> I'm not at all clear what to do with this information. Is there
> >> anything you see in the datasheet [1] that points to something I need
> >> to be doing?
> >
> > You can ignore hdmi_ycc_quantization_range, it is the hdmi_quantization_range
> > that you need to read out.
> >
> > The TDA can receive the following formats:
> >
> > RGB Full Range
> > RGB Limited Range
> > YUV Bt.601 (aka SMPTE 170M)
> > YUV Rec.709
> >
> > The YUV formats are always limited range.
> >
> > The TDA can transmit RGB and YUV to the SoC. You want RGB to be full range and
> > YUV to be limited range. YUV can be either 601 or 709.
> >
> > So if the TDA transmits RGB then you need to support the following conversions:
> >
> > RGB Full -> RGB Full
> > RGB Limited -> RGB Full
> > YUV 601 -> RGB Full
> > YUV 709 -> RGB Full
> >
> > And if the TDA transmits YUV then you need these conversions:
> >
> > RGB Full -> YUV601 or YUV709
> > RGB Limited -> YUV601 or YUV709
> > YUV601 -> YUV601
> > YUV709 -> YUV709
> >
> > For the RGB to YUV conversion you have a choice of converting to YUV601 or 709.
> > I recommend to either always convert to YUV601 or to let it depend on the resolution
> > (SDTV YUV601, HDTV YUV709).
> >
>
> Ok - this is a good explanation that I should be able to follow. I
> will make sure to take into account hdmi_quantization_range when I
> setup the colorspace conversion matrix for v3.
Hans,
I'm having trouble figuring out the conversion matrix to use between
limited and full.
Currently I have the following conversion matrices, the values which
came from some old vendor code:
/* Colorspace conversion matrix coefficients and offsets */
struct color_matrix_coefs {
/* Input offsets */
s16 offint1;
s16 offint2;
s16 offint3;
/* Coeficients */
s16 p11coef;
s16 p12coef;
s16 p13coef;
s16 p21coef;
s16 p22coef;
s16 p23coef;
s16 p31coef;
s16 p32coef;
s16 p33coef;
/* Output offsets */
s16 offout1;
s16 offout2;
s16 offout3;
};
/* Conversion matrixes */
enum {
ITU709_RGBLIMITED,
ITU601_RGBLIMITED,
RGBLIMITED_ITU601,
};
static const struct color_matrix_coefs conv_matrix[] = {
/* ITU709 -> RGBLimited */
{
-256, -2048, -2048,
4096, -1875, -750,
4096, 6307, 0,
4096, 0, 7431,
256, 256, 256,
},
/* YUV601 limited -> RGB limited */
{
-256, -2048, -2048,
4096, -2860, -1378,
4096, 5615, 0,
4096, 0, 7097,
256, 256, 256,
},
/* RGB limited -> ITU601 */
{
-256, -256, -256,
2404, 1225, 467,
-1754, 2095, -341,
-1388, -707, 2095,
256, 2048, 2048,
},
};
Assuming the above are correct this leaves me missing RGB limitted ->
RGB full, YUV601 -> RGB full, YUV709 -> RGB full, and RGB Full ->
YUV601.
I don't have documentation for the registers but I'm assuming the
input offset is applied first, then the multiplication by the coef,
then the output offset is applied. I'm looking over
https://en.wikipedia.org/wiki/YUV for colorspace conversion matrices
but I'm unable to figure out how to apply those to the above. Any
ideas?
Thanks,
Tim
