diff mbox series

[PATCH/RFC,v2,8/9] media: v4l: ctrls: Add a control for companding

Message ID 20240905225308.11267-9-laurent.pinchart@ideasonboard.com
State New
Headers show
Series media: i2c: AR0144 camera sensor driver with companding support | expand

Commit Message

Laurent Pinchart Sept. 5, 2024, 10:53 p.m. UTC 
Companding refers to compression and expansion of pixel data to fit in a
smaller range. The control is named V4L2_CID_COMPANDING, and only
supports compression initially.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
Changes since v1:

- Rename V4L2_COMPANDING_ALAW to V4L2_COMPANDING_COMPRESS
- Document V4L2_COMPANDING_LINEAR and V4L2_COMPANDING_COMPRESS
---
 .../media/v4l/ext-ctrls-image-process.rst        | 16 ++++++++++++++++
 drivers/media/v4l2-core/v4l2-ctrls-defs.c        |  9 +++++++++
 include/uapi/linux/v4l2-controls.h               |  5 +++++
 3 files changed, 30 insertions(+)

Comments

Hans Verkuil Sept. 6, 2024, 5:44 a.m. UTC | #1 
On 06/09/2024 00:53, Laurent Pinchart wrote:
> Companding refers to compression and expansion of pixel data to fit in a
> smaller range. The control is named V4L2_CID_COMPANDING, and only
> supports compression initially.
> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> ---
> Changes since v1:
> 
> - Rename V4L2_COMPANDING_ALAW to V4L2_COMPANDING_COMPRESS
> - Document V4L2_COMPANDING_LINEAR and V4L2_COMPANDING_COMPRESS
> ---
>  .../media/v4l/ext-ctrls-image-process.rst        | 16 ++++++++++++++++
>  drivers/media/v4l2-core/v4l2-ctrls-defs.c        |  9 +++++++++
>  include/uapi/linux/v4l2-controls.h               |  5 +++++
>  3 files changed, 30 insertions(+)
> 
> diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-image-process.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-image-process.rst
> index b1c2ab2854af..d529b0a8cd41 100644
> --- a/Documentation/userspace-api/media/v4l/ext-ctrls-image-process.rst
> +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-image-process.rst
> @@ -55,3 +55,19 @@ Image Process Control IDs
>      control value divided by e.g. 0x100, meaning that to get no
>      digital gain the control value needs to be 0x100. The no-gain
>      configuration is also typically the default.
> +
> +``V4L2_CID_COMPANDING (menu)``
> +    Companding refers to compression and expansion of pixel data to fit in a
> +    smaller range.
> +
> +
> +.. tabularcolumns:: |p{5.7cm}|p{11.8cm}|
> +
> +.. flat-table::
> +    :header-rows:  0
> +    :stub-columns: 0
> +
> +    * - ``V4L2_COMPANDING_LINEAR``
> +      - No companding.
> +    * - ``V4L2_COMPANDING_COMPRESS``

It's weird that this is called 'COMPRESS',

> +      - Compress the data using a device-specific curve.
> diff --git a/drivers/media/v4l2-core/v4l2-ctrls-defs.c b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
> index 1ea52011247a..841e415a88ae 100644
> --- a/drivers/media/v4l2-core/v4l2-ctrls-defs.c
> +++ b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
> @@ -611,6 +611,11 @@ const char * const *v4l2_ctrl_get_menu(u32 id)
>  		"Cyclic",
>  		NULL,
>  	};
> +	static const char * const companding[] = {
> +		"Linear",
> +		"A-Law",

but it is called 'A-Law' here. I think the same name should be used for both
as this is confusing.

Regards,

	Hans

> +		NULL
> +	};
>  
>  	switch (id) {
>  	case V4L2_CID_MPEG_AUDIO_SAMPLING_FREQ:
> @@ -750,6 +755,8 @@ const char * const *v4l2_ctrl_get_menu(u32 id)
>  		return camera_orientation;
>  	case V4L2_CID_MPEG_VIDEO_INTRA_REFRESH_PERIOD_TYPE:
>  		return intra_refresh_period_type;
> +	case V4L2_CID_COMPANDING:
> +		return companding;
>  	default:
>  		return NULL;
>  	}
> @@ -1164,6 +1171,7 @@ const char *v4l2_ctrl_get_name(u32 id)
>  	case V4L2_CID_TEST_PATTERN:		return "Test Pattern";
>  	case V4L2_CID_DEINTERLACING_MODE:	return "Deinterlacing Mode";
>  	case V4L2_CID_DIGITAL_GAIN:		return "Digital Gain";
> +	case V4L2_CID_COMPANDING:		return "Companding";
>  
>  	/* DV controls */
>  	/* Keep the order of the 'case's the same as in v4l2-controls.h! */
> @@ -1421,6 +1429,7 @@ void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
>  	case V4L2_CID_CAMERA_ORIENTATION:
>  	case V4L2_CID_MPEG_VIDEO_INTRA_REFRESH_PERIOD_TYPE:
>  	case V4L2_CID_HDR_SENSOR_MODE:
> +	case V4L2_CID_COMPANDING:
>  		*type = V4L2_CTRL_TYPE_MENU;
>  		break;
>  	case V4L2_CID_LINK_FREQ:
> diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h
> index 974fd254e573..ca9e25f72886 100644
> --- a/include/uapi/linux/v4l2-controls.h
> +++ b/include/uapi/linux/v4l2-controls.h
> @@ -1225,6 +1225,11 @@ enum v4l2_jpeg_chroma_subsampling {
>  #define V4L2_CID_TEST_PATTERN			(V4L2_CID_IMAGE_PROC_CLASS_BASE + 3)
>  #define V4L2_CID_DEINTERLACING_MODE		(V4L2_CID_IMAGE_PROC_CLASS_BASE + 4)
>  #define V4L2_CID_DIGITAL_GAIN			(V4L2_CID_IMAGE_PROC_CLASS_BASE + 5)
> +#define V4L2_CID_COMPANDING			(V4L2_CID_IMAGE_PROC_CLASS_BASE + 6)
> +enum v4l2_companding {
> +	V4L2_COMPANDING_LINEAR		= 0,
> +	V4L2_COMPANDING_COMPRESS	= 1,
> +};
>  
>  /*  DV-class control IDs defined by V4L2 */
>  #define V4L2_CID_DV_CLASS_BASE			(V4L2_CTRL_CLASS_DV | 0x900)
Laurent Pinchart Sept. 6, 2024, 11:55 a.m. UTC | #2 
Hi Hans,

On Fri, Sep 06, 2024 at 07:44:05AM +0200, Hans Verkuil wrote:
> On 06/09/2024 00:53, Laurent Pinchart wrote:
> > Companding refers to compression and expansion of pixel data to fit in a
> > smaller range. The control is named V4L2_CID_COMPANDING, and only
> > supports compression initially.
> > 
> > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > ---
> > Changes since v1:
> > 
> > - Rename V4L2_COMPANDING_ALAW to V4L2_COMPANDING_COMPRESS
> > - Document V4L2_COMPANDING_LINEAR and V4L2_COMPANDING_COMPRESS
> > ---
> >  .../media/v4l/ext-ctrls-image-process.rst        | 16 ++++++++++++++++
> >  drivers/media/v4l2-core/v4l2-ctrls-defs.c        |  9 +++++++++
> >  include/uapi/linux/v4l2-controls.h               |  5 +++++
> >  3 files changed, 30 insertions(+)
> > 
> > diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-image-process.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-image-process.rst
> > index b1c2ab2854af..d529b0a8cd41 100644
> > --- a/Documentation/userspace-api/media/v4l/ext-ctrls-image-process.rst
> > +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-image-process.rst
> > @@ -55,3 +55,19 @@ Image Process Control IDs
> >      control value divided by e.g. 0x100, meaning that to get no
> >      digital gain the control value needs to be 0x100. The no-gain
> >      configuration is also typically the default.
> > +
> > +``V4L2_CID_COMPANDING (menu)``
> > +    Companding refers to compression and expansion of pixel data to fit in a
> > +    smaller range.
> > +
> > +
> > +.. tabularcolumns:: |p{5.7cm}|p{11.8cm}|
> > +
> > +.. flat-table::
> > +    :header-rows:  0
> > +    :stub-columns: 0
> > +
> > +    * - ``V4L2_COMPANDING_LINEAR``
> > +      - No companding.
> > +    * - ``V4L2_COMPANDING_COMPRESS``
> 
> It's weird that this is called 'COMPRESS',
> 
> > +      - Compress the data using a device-specific curve.
> > diff --git a/drivers/media/v4l2-core/v4l2-ctrls-defs.c b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
> > index 1ea52011247a..841e415a88ae 100644
> > --- a/drivers/media/v4l2-core/v4l2-ctrls-defs.c
> > +++ b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
> > @@ -611,6 +611,11 @@ const char * const *v4l2_ctrl_get_menu(u32 id)
> >  		"Cyclic",
> >  		NULL,
> >  	};
> > +	static const char * const companding[] = {
> > +		"Linear",
> > +		"A-Law",
> 
> but it is called 'A-Law' here. I think the same name should be used for both
> as this is confusing.

I forgot to change this. I'll use "Compress".

> > +		NULL
> > +	};
> >  
> >  	switch (id) {
> >  	case V4L2_CID_MPEG_AUDIO_SAMPLING_FREQ:
> > @@ -750,6 +755,8 @@ const char * const *v4l2_ctrl_get_menu(u32 id)
> >  		return camera_orientation;
> >  	case V4L2_CID_MPEG_VIDEO_INTRA_REFRESH_PERIOD_TYPE:
> >  		return intra_refresh_period_type;
> > +	case V4L2_CID_COMPANDING:
> > +		return companding;
> >  	default:
> >  		return NULL;
> >  	}
> > @@ -1164,6 +1171,7 @@ const char *v4l2_ctrl_get_name(u32 id)
> >  	case V4L2_CID_TEST_PATTERN:		return "Test Pattern";
> >  	case V4L2_CID_DEINTERLACING_MODE:	return "Deinterlacing Mode";
> >  	case V4L2_CID_DIGITAL_GAIN:		return "Digital Gain";
> > +	case V4L2_CID_COMPANDING:		return "Companding";
> >  
> >  	/* DV controls */
> >  	/* Keep the order of the 'case's the same as in v4l2-controls.h! */
> > @@ -1421,6 +1429,7 @@ void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
> >  	case V4L2_CID_CAMERA_ORIENTATION:
> >  	case V4L2_CID_MPEG_VIDEO_INTRA_REFRESH_PERIOD_TYPE:
> >  	case V4L2_CID_HDR_SENSOR_MODE:
> > +	case V4L2_CID_COMPANDING:
> >  		*type = V4L2_CTRL_TYPE_MENU;
> >  		break;
> >  	case V4L2_CID_LINK_FREQ:
> > diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h
> > index 974fd254e573..ca9e25f72886 100644
> > --- a/include/uapi/linux/v4l2-controls.h
> > +++ b/include/uapi/linux/v4l2-controls.h
> > @@ -1225,6 +1225,11 @@ enum v4l2_jpeg_chroma_subsampling {
> >  #define V4L2_CID_TEST_PATTERN			(V4L2_CID_IMAGE_PROC_CLASS_BASE + 3)
> >  #define V4L2_CID_DEINTERLACING_MODE		(V4L2_CID_IMAGE_PROC_CLASS_BASE + 4)
> >  #define V4L2_CID_DIGITAL_GAIN			(V4L2_CID_IMAGE_PROC_CLASS_BASE + 5)
> > +#define V4L2_CID_COMPANDING			(V4L2_CID_IMAGE_PROC_CLASS_BASE + 6)
> > +enum v4l2_companding {
> > +	V4L2_COMPANDING_LINEAR		= 0,
> > +	V4L2_COMPANDING_COMPRESS	= 1,
> > +};
> >  
> >  /*  DV-class control IDs defined by V4L2 */
> >  #define V4L2_CID_DV_CLASS_BASE			(V4L2_CTRL_CLASS_DV | 0x900)
diff mbox series

Patch

diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-image-process.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-image-process.rst
index b1c2ab2854af..d529b0a8cd41 100644
--- a/Documentation/userspace-api/media/v4l/ext-ctrls-image-process.rst
+++ b/Documentation/userspace-api/media/v4l/ext-ctrls-image-process.rst
@@ -55,3 +55,19 @@  Image Process Control IDs
     control value divided by e.g. 0x100, meaning that to get no
     digital gain the control value needs to be 0x100. The no-gain
     configuration is also typically the default.
+
+``V4L2_CID_COMPANDING (menu)``
+    Companding refers to compression and expansion of pixel data to fit in a
+    smaller range.
+
+
+.. tabularcolumns:: |p{5.7cm}|p{11.8cm}|
+
+.. flat-table::
+    :header-rows:  0
+    :stub-columns: 0
+
+    * - ``V4L2_COMPANDING_LINEAR``
+      - No companding.
+    * - ``V4L2_COMPANDING_COMPRESS``
+      - Compress the data using a device-specific curve.
diff --git a/drivers/media/v4l2-core/v4l2-ctrls-defs.c b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
index 1ea52011247a..841e415a88ae 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls-defs.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
@@ -611,6 +611,11 @@  const char * const *v4l2_ctrl_get_menu(u32 id)
 		"Cyclic",
 		NULL,
 	};
+	static const char * const companding[] = {
+		"Linear",
+		"A-Law",
+		NULL
+	};
 
 	switch (id) {
 	case V4L2_CID_MPEG_AUDIO_SAMPLING_FREQ:
@@ -750,6 +755,8 @@  const char * const *v4l2_ctrl_get_menu(u32 id)
 		return camera_orientation;
 	case V4L2_CID_MPEG_VIDEO_INTRA_REFRESH_PERIOD_TYPE:
 		return intra_refresh_period_type;
+	case V4L2_CID_COMPANDING:
+		return companding;
 	default:
 		return NULL;
 	}
@@ -1164,6 +1171,7 @@  const char *v4l2_ctrl_get_name(u32 id)
 	case V4L2_CID_TEST_PATTERN:		return "Test Pattern";
 	case V4L2_CID_DEINTERLACING_MODE:	return "Deinterlacing Mode";
 	case V4L2_CID_DIGITAL_GAIN:		return "Digital Gain";
+	case V4L2_CID_COMPANDING:		return "Companding";
 
 	/* DV controls */
 	/* Keep the order of the 'case's the same as in v4l2-controls.h! */
@@ -1421,6 +1429,7 @@  void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
 	case V4L2_CID_CAMERA_ORIENTATION:
 	case V4L2_CID_MPEG_VIDEO_INTRA_REFRESH_PERIOD_TYPE:
 	case V4L2_CID_HDR_SENSOR_MODE:
+	case V4L2_CID_COMPANDING:
 		*type = V4L2_CTRL_TYPE_MENU;
 		break;
 	case V4L2_CID_LINK_FREQ:
diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h
index 974fd254e573..ca9e25f72886 100644
--- a/include/uapi/linux/v4l2-controls.h
+++ b/include/uapi/linux/v4l2-controls.h
@@ -1225,6 +1225,11 @@  enum v4l2_jpeg_chroma_subsampling {
 #define V4L2_CID_TEST_PATTERN			(V4L2_CID_IMAGE_PROC_CLASS_BASE + 3)
 #define V4L2_CID_DEINTERLACING_MODE		(V4L2_CID_IMAGE_PROC_CLASS_BASE + 4)
 #define V4L2_CID_DIGITAL_GAIN			(V4L2_CID_IMAGE_PROC_CLASS_BASE + 5)
+#define V4L2_CID_COMPANDING			(V4L2_CID_IMAGE_PROC_CLASS_BASE + 6)
+enum v4l2_companding {
+	V4L2_COMPANDING_LINEAR		= 0,
+	V4L2_COMPANDING_COMPRESS	= 1,
+};
 
 /*  DV-class control IDs defined by V4L2 */
 #define V4L2_CID_DV_CLASS_BASE			(V4L2_CTRL_CLASS_DV | 0x900)