Re: [PATCH v15 18/19] media: uvcvideo: implement UVC v1.5 ROI

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 14-Nov-24 8:10 PM, Ricardo Ribalda wrote:
> From: Yunke Cao <yunkec@google.com>
> 
> Implement support for ROI as described in UVC 1.5:
> 4.2.2.1.20 Digital Region of Interest (ROI) Control
> 
> ROI control is implemented using V4L2 control API as
> two UVC-specific controls:
> V4L2_CID_UVC_REGION_OF_INTEREST_RECT and
> V4L2_CID_UVC_REGION_OF_INTEREST_AUTO.
> 
> Reviewed-by: Ricardo Ribalda <ribalda@chromium.org>
> Signed-off-by: Yunke Cao <yunkec@google.com>
> ---
>  drivers/media/usb/uvc/uvc_ctrl.c   | 81 ++++++++++++++++++++++++++++++++++++++
>  drivers/media/usb/uvc/uvcvideo.h   |  7 ++++
>  include/uapi/linux/usb/video.h     |  1 +
>  include/uapi/linux/uvcvideo.h      | 13 ++++++
>  include/uapi/linux/v4l2-controls.h |  9 +++++
>  5 files changed, 111 insertions(+)
> 
> diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
> index f262e05ad3a8..5b619ef40dd3 100644
> --- a/drivers/media/usb/uvc/uvc_ctrl.c
> +++ b/drivers/media/usb/uvc/uvc_ctrl.c
> @@ -358,6 +358,24 @@ static const struct uvc_control_info uvc_ctrls[] = {
>  		.flags		= UVC_CTRL_FLAG_GET_CUR
>  				| UVC_CTRL_FLAG_AUTO_UPDATE,
>  	},
> +	/*
> +	 * UVC_CTRL_FLAG_AUTO_UPDATE is needed because the RoI may get updated
> +	 * by sensors.
> +	 * "This RoI should be the same as specified in most recent SET_CUR
> +	 * except in the case where the ‘Auto Detect and Track’ and/or
> +	 * ‘Image Stabilization’ bit have been set."
> +	 * 4.2.2.1.20 Digital Region of Interest (ROI) Control
> +	 */
> +	{
> +		.entity		= UVC_GUID_UVC_CAMERA,
> +		.selector	= UVC_CT_REGION_OF_INTEREST_CONTROL,
> +		.index		= 21,
> +		.size		= 10,
> +		.flags		= UVC_CTRL_FLAG_SET_CUR | UVC_CTRL_FLAG_GET_CUR
> +				| UVC_CTRL_FLAG_GET_MIN | UVC_CTRL_FLAG_GET_MAX
> +				| UVC_CTRL_FLAG_GET_DEF
> +				| UVC_CTRL_FLAG_AUTO_UPDATE,
> +	},
>  };
>  
>  static const u32 uvc_control_classes[] = {
> @@ -603,6 +621,44 @@ static const struct uvc_control_mapping *uvc_ctrl_filter_plf_mapping(
>  	return out_mapping;
>  }
>  
> +static int uvc_get_rect(struct uvc_control_mapping *mapping, u8 query,
> +			const void *uvc_in, size_t v4l2_size, void *v4l2_out)
> +{
> +	const struct uvc_rect *uvc_rect = uvc_in;
> +	struct v4l2_rect *v4l2_rect = v4l2_out;
> +
> +	if (WARN_ON(v4l2_size != sizeof(struct v4l2_rect)))
> +		return -EINVAL;
> +
> +	if (uvc_rect->left > uvc_rect->right ||
> +	    uvc_rect->top > uvc_rect->bottom)
> +		return -EIO;
> +
> +	v4l2_rect->top = uvc_rect->top;
> +	v4l2_rect->left = uvc_rect->left;
> +	v4l2_rect->height = uvc_rect->bottom - uvc_rect->top + 1;
> +	v4l2_rect->width = uvc_rect->right - uvc_rect->left + 1;
> +
> +	return 0;
> +}
> +
> +static int uvc_set_rect(struct uvc_control_mapping *mapping, size_t v4l2_size,
> +			const void *v4l2_in, void *uvc_out)
> +{
> +	struct uvc_rect *uvc_rect = uvc_out;
> +	const struct v4l2_rect *v4l2_rect = v4l2_in;
> +
> +	if (WARN_ON(v4l2_size != sizeof(struct v4l2_rect)))
> +		return -EINVAL;
> +
> +	uvc_rect->top = max(0xffff, v4l2_rect->top);
> +	uvc_rect->left = max(0xffff, v4l2_rect->left);
> +	uvc_rect->bottom = max(0xffff, v4l2_rect->height + v4l2_rect->top - 1);
> +	uvc_rect->right = max(0xffff, v4l2_rect->width + v4l2_rect->left - 1);

As already remarked all 4 lines should be min() not max()

Also this might just be me, but I have a preference for writing top + height
for the bottom rather then writing height + top, since the window starts with
skippig top pixels and then has height pixels filled in. And same for
calculating rect->width. IOW I have a preference for writing this as:

	uvc_rect->bottom = min(0xffff, v4l2_rect->top + v4l2_rect->height - 1);
	uvc_rect->right = min(0xffff, v4l2_rect->left + v4l2_rect->width - 1);

As I said this might just be me, but to me the above reads more naturally.




> +
> +	return 0;
> +}
> +
>  static const struct uvc_control_mapping uvc_ctrl_mappings[] = {
>  	{
>  		.id		= V4L2_CID_BRIGHTNESS,
> @@ -897,6 +953,28 @@ static const struct uvc_control_mapping uvc_ctrl_mappings[] = {
>  		.selector	= UVC_PU_POWER_LINE_FREQUENCY_CONTROL,
>  		.filter_mapping	= uvc_ctrl_filter_plf_mapping,
>  	},
> +	{
> +		.id		= V4L2_CID_UVC_REGION_OF_INTEREST_RECT,
> +		.entity		= UVC_GUID_UVC_CAMERA,
> +		.selector	= UVC_CT_REGION_OF_INTEREST_CONTROL,
> +		.size		= sizeof(struct uvc_rect) * 8,
> +		.offset		= 0,
> +		.v4l2_type	= V4L2_CTRL_TYPE_RECT,
> +		.data_type	= UVC_CTRL_DATA_TYPE_RECT,
> +		.get		= uvc_get_rect,
> +		.set		= uvc_set_rect,
> +		.name		= "Region Of Interest Rectangle",
> +	},
> +	{
> +		.id		= V4L2_CID_UVC_REGION_OF_INTEREST_AUTO,
> +		.entity		= UVC_GUID_UVC_CAMERA,
> +		.selector	= UVC_CT_REGION_OF_INTEREST_CONTROL,
> +		.size		= 16,
> +		.offset		= 64,
> +		.v4l2_type	= V4L2_CTRL_TYPE_BITMASK,
> +		.data_type	= UVC_CTRL_DATA_TYPE_BITMASK,
> +		.name		= "Region Of Interest Auto Controls",
> +	},
>  };
>  
>  /* ------------------------------------------------------------------------
> @@ -1465,6 +1543,9 @@ static int __uvc_queryctrl_boundaries(struct uvc_video_chain *chain,
>  
>  static size_t uvc_mapping_v4l2_size(struct uvc_control_mapping *mapping)
>  {
> +	if (mapping->v4l2_type == V4L2_CTRL_TYPE_RECT)
> +		return sizeof(struct v4l2_rect);
> +
>  	if (uvc_ctrl_mapping_is_compound(mapping))
>  		return DIV_ROUND_UP(mapping->size, 8);
>  
> diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
> index 8aca1a2fe587..d910a5e5b514 100644
> --- a/drivers/media/usb/uvc/uvcvideo.h
> +++ b/drivers/media/usb/uvc/uvcvideo.h
> @@ -294,6 +294,13 @@ struct uvc_streaming_header {
>  	u8 bTriggerUsage;
>  };
>  
> +struct uvc_rect {
> +	u16 top;
> +	u16 left;
> +	u16 bottom;
> +	u16 right;
> +} __packed;
> +

This should probably be grouped togather with uvc_status_* structs which are
also marked __packed because they represent hw API rather then just host
in memory structures.

>  enum uvc_buffer_state {
>  	UVC_BUF_STATE_IDLE	= 0,
>  	UVC_BUF_STATE_QUEUED	= 1,
> diff --git a/include/uapi/linux/usb/video.h b/include/uapi/linux/usb/video.h
> index 2ff0e8a3a683..2afb4420e6c4 100644
> --- a/include/uapi/linux/usb/video.h
> +++ b/include/uapi/linux/usb/video.h
> @@ -104,6 +104,7 @@
>  #define UVC_CT_ROLL_ABSOLUTE_CONTROL			0x0f
>  #define UVC_CT_ROLL_RELATIVE_CONTROL			0x10
>  #define UVC_CT_PRIVACY_CONTROL				0x11
> +#define UVC_CT_REGION_OF_INTEREST_CONTROL		0x14
>  
>  /* A.9.5. Processing Unit Control Selectors */
>  #define UVC_PU_CONTROL_UNDEFINED			0x00
> diff --git a/include/uapi/linux/uvcvideo.h b/include/uapi/linux/uvcvideo.h
> index f86185456dc5..cbe15bca9569 100644
> --- a/include/uapi/linux/uvcvideo.h
> +++ b/include/uapi/linux/uvcvideo.h
> @@ -16,6 +16,7 @@
>  #define UVC_CTRL_DATA_TYPE_BOOLEAN	3
>  #define UVC_CTRL_DATA_TYPE_ENUM		4
>  #define UVC_CTRL_DATA_TYPE_BITMASK	5
> +#define UVC_CTRL_DATA_TYPE_RECT		6
>  
>  /* Control flags */
>  #define UVC_CTRL_FLAG_SET_CUR		(1 << 0)
> @@ -38,6 +39,18 @@
>  
>  #define UVC_MENU_NAME_LEN 32
>  
> +/* V4L2 driver-specific controls */
> +#define V4L2_CID_UVC_REGION_OF_INTEREST_RECT	(V4L2_CID_USER_UVC_BASE + 1)
> +#define V4L2_CID_UVC_REGION_OF_INTEREST_AUTO	(V4L2_CID_USER_UVC_BASE + 2)
> +#define V4L2_UVC_REGION_OF_INTEREST_AUTO_EXPOSURE		(1 << 0)
> +#define V4L2_UVC_REGION_OF_INTEREST_AUTO_IRIS			(1 << 1)
> +#define V4L2_UVC_REGION_OF_INTEREST_AUTO_WHITE_BALANCE		(1 << 2)
> +#define V4L2_UVC_REGION_OF_INTEREST_AUTO_FOCUS			(1 << 3)
> +#define V4L2_UVC_REGION_OF_INTEREST_AUTO_FACE_DETECT		(1 << 4)
> +#define V4L2_UVC_REGION_OF_INTEREST_AUTO_DETECT_AND_TRACK	(1 << 5)
> +#define V4L2_UVC_REGION_OF_INTEREST_AUTO_IMAGE_STABILIZATION	(1 << 6)
> +#define V4L2_UVC_REGION_OF_INTEREST_AUTO_HIGHER_QUALITY		(1 << 7)
> +

Hmm, shoudn't these be standardized. At least the ROI rect control seems like
something which could be standardized ?

Was using driver specific CIDs for this discussed with Hans Verkuil ?

>  struct uvc_menu_info {
>  	__u32 value;
>  	__u8 name[UVC_MENU_NAME_LEN];
> diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h
> index 974fd254e573..6c91d6fa4708 100644
> --- a/include/uapi/linux/v4l2-controls.h
> +++ b/include/uapi/linux/v4l2-controls.h
> @@ -215,6 +215,13 @@ enum v4l2_colorfx {
>   */
>  #define V4L2_CID_USER_THP7312_BASE		(V4L2_CID_USER_BASE + 0x11c0)
>  
> +/*
> + * The base for the uvc driver controls.
> + * See linux/uvcvideo.h for the list of controls.
> + * We reserve 64 controls for this driver.
> + */
> +#define V4L2_CID_USER_UVC_BASE			(V4L2_CID_USER_BASE + 0x11e0)
> +
>  /* MPEG-class control IDs */
>  /* The MPEG controls are applicable to all codec controls
>   * and the 'MPEG' part of the define is historical */
> @@ -1089,6 +1096,8 @@ enum v4l2_auto_focus_range {
>  
>  #define V4L2_CID_HDR_SENSOR_MODE		(V4L2_CID_CAMERA_CLASS_BASE+36)
>  
> +/* CAMERA-class private control IDs */
> +
>  /* FM Modulator class control IDs */
>  
>  #define V4L2_CID_FM_TX_CLASS_BASE		(V4L2_CTRL_CLASS_FM_TX | 0x900)
> 


Regards,

Hans