Hi Jacopo, On Tuesday, 20 February 2018 10:58:57 EET jacopo mondi wrote: > On Mon, Feb 19, 2018 at 09:19:32PM +0200, Laurent Pinchart wrote: > > On Monday, 19 February 2018 18:59:44 EET Jacopo Mondi wrote: > >> The sensor driver sets mbus format colorspace information and sizes, > >> but not ycbcr encoding, quantization and xfer function. When supplied > >> with an badly initialized mbus frame format structure, those fields > >> need to be set explicitly not to leave them uninitialized. This is > >> tested by v4l2-compliance, which supplies a mbus format description > >> structure and checks for all fields to be properly set. > >> > >> Without this commit, v4l2-compliance fails when testing formats with: > >> fail: v4l2-test-formats.cpp(335): ycbcr_enc >= 0xff > >> > >> Signed-off-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx> > >> --- > >> > >> drivers/media/i2c/ov7670.c | 4 ++++ > >> 1 file changed, 4 insertions(+) > >> > >> diff --git a/drivers/media/i2c/ov7670.c b/drivers/media/i2c/ov7670.c > >> index 25b26d4..61c472e 100644 > >> --- a/drivers/media/i2c/ov7670.c > >> +++ b/drivers/media/i2c/ov7670.c > >> @@ -996,6 +996,10 @@ static int ov7670_try_fmt_internal(struct > >> v4l2_subdev > >> *sd, fmt->height = wsize->height; > >> > >> fmt->colorspace = ov7670_formats[index].colorspace; > > > > On a side note, if I'm not mistaken the colorspace field is set to SRGB > > for all entries. Shouldn't you hardcode it here and remove the field ? > > > >> + fmt->ycbcr_enc = V4L2_YCBCR_ENC_DEFAULT; > >> + fmt->quantization = V4L2_QUANTIZATION_DEFAULT; > >> + fmt->xfer_func = V4L2_XFER_FUNC_DEFAULT; > > > > How about setting the values explicitly instead of relying on defaults ? > > That would be V4L2_YCBCR_ENC_601, V4L2_QUANTIZATION_LIM_RANGE and > > V4L2_XFER_FUNC_SRGB. And could you then check a captured frame to see if > > the sensor outputs limited or full range ? > > This actually makes me wonder if those informations (ycbcb_enc, > quantization and xfer_func) shouldn't actually be part of the > supported format list... I blindly added those default fields in the > try_fmt function, but I doubt they applies to all supported formats. > > Eg. the sensor supports YUYV as well as 2 RGB encodings (RGB444 and > RGB 565) and 1 raw format (BGGR). I now have a question here: > > 1) ycbcr_enc transforms non-linear R'G'B' to Y'CbCr: does this > applies to RGB and raw formats? I don't think so, and what value is > the correct one for the ycbcr_enc field in this case? I assume > xfer_func and quantization applies to all formats instead.. There's no encoding for RGB formats if I understand things correctly, so I'd set ycbcr_enc to V4L2_YCBCR_ENC_DEFAULT. The transfer function and the quantization apply to all formats, but I'd be surprised to find a sensor outputting limited range for RGB. Have you been able to check whether the sensor outputs limited range of full range YUV ? If it outputs full range you can hardcode quantization to V4L2_QUANTIZATION_FULL_RANGE for all formats. > >> info->format = *fmt; > >> > >> return 0; -- Regards, Laurent Pinchart
