Re: [PATCH v2 1/3] v4l: Add HDR10 static metadata controls

[Stanimir Varbanov]

Hi Hans,

On 12/7/20 11:21 AM, Hans Verkuil wrote:
> On 07/12/2020 10:06, Stanimir Varbanov wrote:
>>
>>
>> On 12/2/20 1:12 PM, Hans Verkuil wrote:
>>> On 24/11/2020 00:02, Stanimir Varbanov wrote:
>>>> Add Content light level and Mastering display colour volume v4l2
>>>> compounf controls, relevant payload structures and validation.
>>>
>>> compounf -> compound
>>>
>>>>
>>>> Signed-off-by: Stanimir Varbanov <stanimir.varbanov@xxxxxxxxxx>
>>>> ---
>>>>  drivers/media/v4l2-core/v4l2-ctrls.c | 62 ++++++++++++++++++++++++++++
>>>>  include/media/hdr10-ctrls.h          | 55 ++++++++++++++++++++++++
>>>>  include/media/v4l2-ctrls.h           |  3 ++
>>>>  3 files changed, 120 insertions(+)
>>>>  create mode 100644 include/media/hdr10-ctrls.h
>>>>
>>>> diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
>>>> index ad47d00e28d6..028630576401 100644
>>>> --- a/drivers/media/v4l2-core/v4l2-ctrls.c
>>>> +++ b/drivers/media/v4l2-core/v4l2-ctrls.c
>>>> @@ -1024,6 +1024,9 @@ const char *v4l2_ctrl_get_name(u32 id)
>>>>  	case V4L2_CID_MPEG_VIDEO_HEVC_DECODE_MODE:		return "HEVC Decode Mode";
>>>>  	case V4L2_CID_MPEG_VIDEO_HEVC_START_CODE:		return "HEVC Start Code";
>>>>  
>>>> +	case V4L2_CID_MPEG_VIDEO_HDR10_CLL_INFO:		return "HDR10 Content Light Info";
>>>> +	case V4L2_CID_MPEG_VIDEO_HDR10_MASTERING_DISPLAY:	return "HDR10 Mastering Display";
>>>> +
>>>>  	/* CAMERA controls */
>>>>  	/* Keep the order of the 'case's the same as in v4l2-controls.h! */
>>>>  	case V4L2_CID_CAMERA_CLASS:		return "Camera Controls";
>>>> @@ -1461,6 +1464,12 @@ void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
>>>>  	case V4L2_CID_MPEG_VIDEO_HEVC_SLICE_PARAMS:
>>>>  		*type = V4L2_CTRL_TYPE_HEVC_SLICE_PARAMS;
>>>>  		break;
>>>> +	case V4L2_CID_MPEG_VIDEO_HDR10_CLL_INFO:
>>>> +		*type = V4L2_CTRL_TYPE_HDR10_CLL_INFO;
>>>> +		break;
>>>> +	case V4L2_CID_MPEG_VIDEO_HDR10_MASTERING_DISPLAY:
>>>> +		*type = V4L2_CTRL_TYPE_HDR10_MASTERING_DISPLAY;
>>>> +		break;
>>>>  	case V4L2_CID_UNIT_CELL_SIZE:
>>>>  		*type = V4L2_CTRL_TYPE_AREA;
>>>>  		*flags |= V4L2_CTRL_FLAG_READ_ONLY;
>>>> @@ -1775,6 +1784,7 @@ static int std_validate_compound(const struct v4l2_ctrl *ctrl, u32 idx,
>>>>  	struct v4l2_ctrl_hevc_sps *p_hevc_sps;
>>>>  	struct v4l2_ctrl_hevc_pps *p_hevc_pps;
>>>>  	struct v4l2_ctrl_hevc_slice_params *p_hevc_slice_params;
>>>> +	struct v4l2_ctrl_hdr10_mastering_display *p_hdr10_mastering;
>>>>  	struct v4l2_area *area;
>>>>  	void *p = ptr.p + idx * ctrl->elem_size;
>>>>  	unsigned int i;
>>>> @@ -1934,6 +1944,52 @@ static int std_validate_compound(const struct v4l2_ctrl *ctrl, u32 idx,
>>>>  		zero_padding(*p_hevc_slice_params);
>>>>  		break;
>>>>  
>>>> +	case V4L2_CTRL_TYPE_HDR10_CLL_INFO:
>>>> +		break;
>>>> +
>>>> +	case V4L2_CTRL_TYPE_HDR10_MASTERING_DISPLAY:
>>>> +		p_hdr10_mastering = p;
>>>> +
>>>> +		for (i = 0; i < 3; ++i) {
>>>> +			if (p_hdr10_mastering->display_primaries_x[i] <
>>>> +				V4L2_HDR10_MASTERING_PRIMARIES_X_LOW ||
>>>> +			    p_hdr10_mastering->display_primaries_x[i] >
>>>> +				V4L2_HDR10_MASTERING_PRIMARIES_X_HIGH ||
>>>> +			    p_hdr10_mastering->display_primaries_y[i] <
>>>> +				V4L2_HDR10_MASTERING_PRIMARIES_Y_LOW ||
>>>> +			    p_hdr10_mastering->display_primaries_y[i] >
>>>> +				V4L2_HDR10_MASTERING_PRIMARIES_Y_HIGH)
>>>> +				return -EINVAL;
>>>> +		}
>>>> +
>>>> +		if (p_hdr10_mastering->white_point_x <
>>>> +			V4L2_HDR10_MASTERING_WHITE_POINT_X_LOW ||
>>>> +		    p_hdr10_mastering->white_point_x >
>>>> +			V4L2_HDR10_MASTERING_WHITE_POINT_X_HIGH ||
>>>> +		    p_hdr10_mastering->white_point_y <
>>>> +			V4L2_HDR10_MASTERING_WHITE_POINT_Y_LOW ||
>>>> +		    p_hdr10_mastering->white_point_y >
>>>> +			V4L2_HDR10_MASTERING_WHITE_POINT_Y_HIGH)
>>>> +			return -EINVAL;
>>>> +
>>>> +		if (p_hdr10_mastering->max_luminance <
>>>> +			V4L2_HDR10_MASTERING_MAX_LUMA_LOW ||
>>>> +		    p_hdr10_mastering->max_luminance >
>>>> +			V4L2_HDR10_MASTERING_MAX_LUMA_HIGH ||
>>>> +		    p_hdr10_mastering->min_luminance <
>>>> +			V4L2_HDR10_MASTERING_MIN_LUMA_LOW ||
>>>> +		    p_hdr10_mastering->min_luminance >
>>>> +			V4L2_HDR10_MASTERING_MIN_LUMA_HIGH)
>>>> +			return -EINVAL;
>>>> +
>>>> +		if (p_hdr10_mastering->max_luminance ==
>>>> +			V4L2_HDR10_MASTERING_MAX_LUMA_LOW &&
>>>> +		    p_hdr10_mastering->min_luminance ==
>>>> +			V4L2_HDR10_MASTERING_MIN_LUMA_HIGH)
>>>> +			return -EINVAL;
>>>> +
>>>> +		break;
>>>> +
>>>>  	case V4L2_CTRL_TYPE_AREA:
>>>>  		area = p;
>>>>  		if (!area->width || !area->height)
>>>> @@ -2626,6 +2682,12 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct v4l2_ctrl_handler *hdl,
>>>>  	case V4L2_CTRL_TYPE_HEVC_SLICE_PARAMS:
>>>>  		elem_size = sizeof(struct v4l2_ctrl_hevc_slice_params);
>>>>  		break;
>>>> +	case V4L2_CTRL_TYPE_HDR10_CLL_INFO:
>>>> +		elem_size = sizeof(struct v4l2_ctrl_hdr10_cll_info);
>>>> +		break;
>>>> +	case V4L2_CTRL_TYPE_HDR10_MASTERING_DISPLAY:
>>>> +		elem_size = sizeof(struct v4l2_ctrl_hdr10_mastering_display);
>>>> +		break;
>>>>  	case V4L2_CTRL_TYPE_AREA:
>>>>  		elem_size = sizeof(struct v4l2_area);
>>>>  		break;
>>>> diff --git a/include/media/hdr10-ctrls.h b/include/media/hdr10-ctrls.h
>>>> new file mode 100644
>>>> index 000000000000..f6f77edc0b60
>>>> --- /dev/null
>>>> +++ b/include/media/hdr10-ctrls.h
>>>> @@ -0,0 +1,55 @@
>>>> +/* SPDX-License-Identifier: GPL-2.0 */
>>>> +/*
>>>> + * These are the HEVC state controls for use with stateless HEVC
>>>> + * codec drivers.
>>>> + *
>>>> + * It turns out that these structs are not stable yet and will undergo
>>>> + * more changes. So keep them private until they are stable and ready to
>>>> + * become part of the official public API.
>>>> + */
>>>> +
>>>> +#ifndef _HDR10_CTRLS_H_
>>>> +#define _HDR10_CTRLS_H_
>>>> +
>>>> +/*
>>>> + * Content light level information.
>>>> + * Source Rec. ITU-T H.265 v7 (11/2019) HEVC; D.2.35
>>>> + */
>>>> +#define V4L2_CID_MPEG_VIDEO_HDR10_CLL_INFO	(V4L2_CID_MPEG_BASE + 1017)
>>>> +#define V4L2_CTRL_TYPE_HDR10_CLL_INFO		0x0123
>>>> +
>>>> +struct v4l2_ctrl_hdr10_cll_info {
>>>> +	__u16 max_content_light_level;
>>>> +	__u16 max_pic_average_light_level;
>>>> +};
>>>> +
>>>> +/*
>>>> + * Mastering display colour volume.
>>>> + * Source Rec. ITU-T H.265 v7 (11/2019) HEVC; D.2.28
>>>> + */
>>>> +#define V4L2_CID_MPEG_VIDEO_HDR10_MASTERING_DISPLAY (V4L2_CID_MPEG_BASE + 1018)
>>>
>>> I don't think this should be part of the codec control class. It is also needed
>>> for HDMI receivers, for example.
>>>
>>> I think it is better to create a new "Colorimetry" control class for controls like
>>> this.
>>
>> I guess in this case I need to create a new ext-ctrls-colorimetry.rst,
>> right?
> 
> Yes.
> 
>>
>>>
>>> But I advise that you wait until this PR is merged:
>>> https://patchwork.linuxtv.org/project/linux-media/patch/d68da172-b251-000f-653d-38a8a4c7b715@xxxxxxxxx/
>>>
>>> Note that you also need to add validation support for this to std_validate_compound()
>>> and possibly add initialization to std_init_compound() is v4l2-ctrls.c.
>>
>> The patch has validation for mastering display already. But I wonder do
>> we really need this validation because CTA-861-G is more liberal about
>> the values comparing with Rec. ITU-T H.265. Or the other option is to
>> combine both of them?
> 
> After thinking about this a bit more, validation makes no sense for decoders
> or HDMI/DP receivers: you have no control over the contents of this data in
> those cases, it should just contain what you receive as-is, and if you receive
> buggy data, then userspace has to decide what to do with that.
> 
> This is something that should be documented, I think. You have to be aware as
> userspace that the data needs to be checked for validity.
> 
> For encoders and HDMI/DP output validation would make sense, but I think that
> for now we should just drop validation altogether.

Well, my doubts expressed above wasn't do we need validation or not but
for the ranges of the parameters CTA-861-G vs Rec. ITU-T H.265.

In that regard I think it is better to have validation for encoders
because out of spec ranges could be dangerous for display panels.

> 
> Regards,
> 
> 	Hans
> 
>>
>>>
>>> Regards,
>>>
>>> 	Hans
>>>
>>>> +#define V4L2_CTRL_TYPE_HDR10_MASTERING_DISPLAY	0x0124
>>>> +
>>>> +#define V4L2_HDR10_MASTERING_PRIMARIES_X_LOW	5
>>>> +#define V4L2_HDR10_MASTERING_PRIMARIES_X_HIGH	37000
>>>> +#define V4L2_HDR10_MASTERING_PRIMARIES_Y_LOW	5
>>>> +#define V4L2_HDR10_MASTERING_PRIMARIES_Y_HIGH	42000
>>>> +#define V4L2_HDR10_MASTERING_WHITE_POINT_X_LOW	5
>>>> +#define V4L2_HDR10_MASTERING_WHITE_POINT_X_HIGH	37000
>>>> +#define V4L2_HDR10_MASTERING_WHITE_POINT_Y_LOW	5
>>>> +#define V4L2_HDR10_MASTERING_WHITE_POINT_Y_HIGH	42000
>>>> +#define V4L2_HDR10_MASTERING_MAX_LUMA_LOW	50000
>>>> +#define V4L2_HDR10_MASTERING_MAX_LUMA_HIGH	100000000
>>>> +#define V4L2_HDR10_MASTERING_MIN_LUMA_LOW	1
>>>> +#define V4L2_HDR10_MASTERING_MIN_LUMA_HIGH	50000
>>>> +
>>>> +struct v4l2_ctrl_hdr10_mastering_display {
>>>> +	__u16 display_primaries_x[3];
>>>> +	__u16 display_primaries_y[3];
>>>> +	__u16 white_point_x;
>>>> +	__u16 white_point_y;
>>>> +	__u32 max_luminance;
>>>> +	__u32 min_luminance;
>>>> +};
>>>> +
>>>> +#endif
>>>> diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
>>>> index 4fbace0fc7e5..81bd026fc1ea 100644
>>>> --- a/include/media/v4l2-ctrls.h
>>>> +++ b/include/media/v4l2-ctrls.h
>>>> @@ -19,6 +19,7 @@
>>>>   */
>>>>  #include <media/mpeg2-ctrls.h>
>>>>  #include <media/fwht-ctrls.h>
>>>> +#include <media/hdr10-ctrls.h>
>>>>  #include <media/h264-ctrls.h>
>>>>  #include <media/vp8-ctrls.h>
>>>>  #include <media/hevc-ctrls.h>
>>>> @@ -80,6 +81,8 @@ union v4l2_ctrl_ptr {
>>>>  	struct v4l2_ctrl_hevc_sps *p_hevc_sps;
>>>>  	struct v4l2_ctrl_hevc_pps *p_hevc_pps;
>>>>  	struct v4l2_ctrl_hevc_slice_params *p_hevc_slice_params;
>>>> +	struct v4l2_ctrl_hdr10_cll_info *p_hdr10_cll;
>>>> +	struct v4l2_ctrl_hdr10_mastering_display *p_hdr10_mastering;
>>>>  	struct v4l2_area *p_area;
>>>>  	void *p;
>>>>  	const void *p_const;
>>>>
>>>
>>
> 

-- 
regards,
Stan