[PATCH 0/2] Add V4L2_BUF_TYPE_META_OUTPUT buffer type

[PATCH 0/2] Add V4L2_BUF_TYPE_META_OUTPUT buffer type

[Sakari Ailus]

Hi folks,

Here's a non-RFC version of the META_OUTPUT buffer type patches.

The V4L2_BUF_TYPE_META_OUTPUT buffer type complements the metadata buffer
types support for OUTPUT buffers, capture being already supported. This is
intended for similar cases than V4L2_BUF_TYPE_META_CAPTURE but for output
buffers, e.g. device parameters that may be complex and highly
hierarchical data structure. Statistics are a current use case for
metadata capture buffers.

Yong: could you take these to your IPU3 ImgU patchset, please? As that
would be the first user, the patches would be merged with the driver
itself.

since RFC:

- Fix make htmldocs build.

- Fix CAPTURE -> OUTPUT in buffer.rst.

- Added " for specifying how the device processes images" in the
  documentation.

Sakari Ailus (2):
  v4l: Add support for V4L2_BUF_TYPE_META_OUTPUT
  docs-rst: v4l: Document V4L2_BUF_TYPE_META_OUTPUT interface

 Documentation/media/uapi/v4l/buffer.rst          |  3 +++
 Documentation/media/uapi/v4l/dev-meta.rst        | 33 ++++++++++++++----------
 Documentation/media/uapi/v4l/vidioc-querycap.rst |  3 +++
 Documentation/media/videodev2.h.rst.exceptions   |  2 ++
 drivers/media/v4l2-core/v4l2-compat-ioctl32.c    |  2 ++
 drivers/media/v4l2-core/v4l2-ioctl.c             | 25 ++++++++++++++++++
 drivers/media/v4l2-core/videobuf2-v4l2.c         |  1 +
 include/media/v4l2-ioctl.h                       | 17 ++++++++++++
 include/uapi/linux/videodev2.h                   |  2 ++
 9 files changed, 75 insertions(+), 13 deletions(-)

-- 
2.7.4

[PATCH 1/2] v4l: Add support for V4L2_BUF_TYPE_META_OUTPUT

[Sakari Ailus]

The V4L2_BUF_TYPE_META_OUTPUT mirrors the V4L2_BUF_TYPE_META_CAPTURE with
the exception that it is an OUTPUT type. The use case for this is to pass
buffers to the device that are not image data but metadata. The formats,
just as the metadata capture formats, are typically device specific and
highly structured.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/v4l2-core/v4l2-compat-ioctl32.c |  2 ++
 drivers/media/v4l2-core/v4l2-ioctl.c          | 25 +++++++++++++++++++++++++
 drivers/media/v4l2-core/videobuf2-v4l2.c      |  1 +
 include/media/v4l2-ioctl.h                    | 17 +++++++++++++++++
 include/uapi/linux/videodev2.h                |  2 ++
 5 files changed, 47 insertions(+)

diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
index af8b4c5..1ea99a7 100644
--- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
+++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
@@ -235,6 +235,7 @@ static int __get_v4l2_format32(struct v4l2_format *kp, struct v4l2_format32 __us
 	case V4L2_BUF_TYPE_SDR_OUTPUT:
 		return get_v4l2_sdr_format(&kp->fmt.sdr, &up->fmt.sdr);
 	case V4L2_BUF_TYPE_META_CAPTURE:
+	case V4L2_BUF_TYPE_META_OUTPUT:
 		return get_v4l2_meta_format(&kp->fmt.meta, &up->fmt.meta);
 	default:
 		pr_info("compat_ioctl32: unexpected VIDIOC_FMT type %d\n",
@@ -284,6 +285,7 @@ static int __put_v4l2_format32(struct v4l2_format *kp, struct v4l2_format32 __us
 	case V4L2_BUF_TYPE_SDR_OUTPUT:
 		return put_v4l2_sdr_format(&kp->fmt.sdr, &up->fmt.sdr);
 	case V4L2_BUF_TYPE_META_CAPTURE:
+	case V4L2_BUF_TYPE_META_OUTPUT:
 		return put_v4l2_meta_format(&kp->fmt.meta, &up->fmt.meta);
 	default:
 		pr_info("compat_ioctl32: unexpected VIDIOC_FMT type %d\n",
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index cab63bb..df9f046 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -157,6 +157,7 @@ const char *v4l2_type_names[] = {
 	[V4L2_BUF_TYPE_SDR_CAPTURE]        = "sdr-cap",
 	[V4L2_BUF_TYPE_SDR_OUTPUT]         = "sdr-out",
 	[V4L2_BUF_TYPE_META_CAPTURE]       = "meta-cap",
+	[V4L2_BUF_TYPE_META_OUTPUT]	   = "meta-out",
 };
 EXPORT_SYMBOL(v4l2_type_names);
 
@@ -329,6 +330,7 @@ static void v4l_print_format(const void *arg, bool write_only)
 			(sdr->pixelformat >> 24) & 0xff);
 		break;
 	case V4L2_BUF_TYPE_META_CAPTURE:
+	case V4L2_BUF_TYPE_META_OUTPUT:
 		meta = &p->fmt.meta;
 		pr_cont(", dataformat=%c%c%c%c, buffersize=%u\n",
 			(meta->dataformat >>  0) & 0xff,
@@ -959,6 +961,10 @@ static int check_fmt(struct file *file, enum v4l2_buf_type type)
 		if (is_vid && is_rx && ops->vidioc_g_fmt_meta_cap)
 			return 0;
 		break;
+	case V4L2_BUF_TYPE_META_OUTPUT:
+		if (is_vid && is_tx && ops->vidioc_g_fmt_meta_out)
+			return 0;
+		break;
 	default:
 		break;
 	}
@@ -1353,6 +1359,11 @@ static int v4l_enum_fmt(const struct v4l2_ioctl_ops *ops,
 			break;
 		ret = ops->vidioc_enum_fmt_meta_cap(file, fh, arg);
 		break;
+	case V4L2_BUF_TYPE_META_OUTPUT:
+		if (unlikely(!is_tx || !is_vid || !ops->vidioc_enum_fmt_meta_out))
+			break;
+		ret = ops->vidioc_enum_fmt_meta_out(file, fh, arg);
+		break;
 	}
 	if (ret == 0)
 		v4l_fill_fmtdesc(p);
@@ -1456,6 +1467,10 @@ static int v4l_g_fmt(const struct v4l2_ioctl_ops *ops,
 		if (unlikely(!is_rx || !is_vid || !ops->vidioc_g_fmt_meta_cap))
 			break;
 		return ops->vidioc_g_fmt_meta_cap(file, fh, arg);
+	case V4L2_BUF_TYPE_META_OUTPUT:
+		if (unlikely(!is_tx || !is_vid || !ops->vidioc_g_fmt_meta_out))
+			break;
+		return ops->vidioc_g_fmt_meta_out(file, fh, arg);
 	}
 	return -EINVAL;
 }
@@ -1566,6 +1581,11 @@ static int v4l_s_fmt(const struct v4l2_ioctl_ops *ops,
 			break;
 		CLEAR_AFTER_FIELD(p, fmt.meta);
 		return ops->vidioc_s_fmt_meta_cap(file, fh, arg);
+	case V4L2_BUF_TYPE_META_OUTPUT:
+		if (unlikely(!is_tx || !is_vid || !ops->vidioc_s_fmt_meta_out))
+			break;
+		CLEAR_AFTER_FIELD(p, fmt.meta);
+		return ops->vidioc_s_fmt_meta_out(file, fh, arg);
 	}
 	return -EINVAL;
 }
@@ -1656,6 +1676,11 @@ static int v4l_try_fmt(const struct v4l2_ioctl_ops *ops,
 			break;
 		CLEAR_AFTER_FIELD(p, fmt.meta);
 		return ops->vidioc_try_fmt_meta_cap(file, fh, arg);
+	case V4L2_BUF_TYPE_META_OUTPUT:
+		if (unlikely(!is_tx || !is_vid || !ops->vidioc_try_fmt_meta_out))
+			break;
+		CLEAR_AFTER_FIELD(p, fmt.meta);
+		return ops->vidioc_try_fmt_meta_out(file, fh, arg);
 	}
 	return -EINVAL;
 }
diff --git a/drivers/media/v4l2-core/videobuf2-v4l2.c b/drivers/media/v4l2-core/videobuf2-v4l2.c
index 0c06699..f17f6d7 100644
--- a/drivers/media/v4l2-core/videobuf2-v4l2.c
+++ b/drivers/media/v4l2-core/videobuf2-v4l2.c
@@ -545,6 +545,7 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
 		requested_sizes[0] = f->fmt.sdr.buffersize;
 		break;
 	case V4L2_BUF_TYPE_META_CAPTURE:
+	case V4L2_BUF_TYPE_META_OUTPUT:
 		requested_sizes[0] = f->fmt.meta.buffersize;
 		break;
 	default:
diff --git a/include/media/v4l2-ioctl.h b/include/media/v4l2-ioctl.h
index bd53121..696bd13 100644
--- a/include/media/v4l2-ioctl.h
+++ b/include/media/v4l2-ioctl.h
@@ -47,6 +47,9 @@ struct v4l2_fh;
  * @vidioc_enum_fmt_meta_cap: pointer to the function that implements
  *	:ref:`VIDIOC_ENUM_FMT <vidioc_enum_fmt>` ioctl logic
  *	for metadata capture
+ * @vidioc_enum_fmt_meta_out: pointer to the function that implements
+ *	:ref:`VIDIOC_ENUM_FMT <vidioc_enum_fmt>` ioctl logic
+ *	for metadata output
  * @vidioc_g_fmt_vid_cap: pointer to the function that implements
  *	:ref:`VIDIOC_G_FMT <vidioc_g_fmt>` ioctl logic for video capture
  *	in single plane mode
@@ -79,6 +82,8 @@ struct v4l2_fh;
  *	Radio output
  * @vidioc_g_fmt_meta_cap: pointer to the function that implements
  *	:ref:`VIDIOC_G_FMT <vidioc_g_fmt>` ioctl logic for metadata capture
+ * @vidioc_g_fmt_meta_out: pointer to the function that implements
+ *	:ref:`VIDIOC_G_FMT <vidioc_g_fmt>` ioctl logic for metadata output
  * @vidioc_s_fmt_vid_cap: pointer to the function that implements
  *	:ref:`VIDIOC_S_FMT <vidioc_g_fmt>` ioctl logic for video capture
  *	in single plane mode
@@ -111,6 +116,8 @@ struct v4l2_fh;
  *	Radio output
  * @vidioc_s_fmt_meta_cap: pointer to the function that implements
  *	:ref:`VIDIOC_S_FMT <vidioc_g_fmt>` ioctl logic for metadata capture
+ * @vidioc_s_fmt_meta_out: pointer to the function that implements
+ *	:ref:`VIDIOC_S_FMT <vidioc_g_fmt>` ioctl logic for metadata output
  * @vidioc_try_fmt_vid_cap: pointer to the function that implements
  *	:ref:`VIDIOC_TRY_FMT <vidioc_g_fmt>` ioctl logic for video capture
  *	in single plane mode
@@ -145,6 +152,8 @@ struct v4l2_fh;
  *	Radio output
  * @vidioc_try_fmt_meta_cap: pointer to the function that implements
  *	:ref:`VIDIOC_TRY_FMT <vidioc_g_fmt>` ioctl logic for metadata capture
+ * @vidioc_try_fmt_meta_out: pointer to the function that implements
+ *	:ref:`VIDIOC_TRY_FMT <vidioc_g_fmt>` ioctl logic for metadata output
  * @vidioc_reqbufs: pointer to the function that implements
  *	:ref:`VIDIOC_REQBUFS <vidioc_reqbufs>` ioctl
  * @vidioc_querybuf: pointer to the function that implements
@@ -317,6 +326,8 @@ struct v4l2_ioctl_ops {
 				       struct v4l2_fmtdesc *f);
 	int (*vidioc_enum_fmt_meta_cap)(struct file *file, void *fh,
 					struct v4l2_fmtdesc *f);
+	int (*vidioc_enum_fmt_meta_out)(struct file *file, void *fh,
+					struct v4l2_fmtdesc *f);
 
 	/* VIDIOC_G_FMT handlers */
 	int (*vidioc_g_fmt_vid_cap)(struct file *file, void *fh,
@@ -345,6 +356,8 @@ struct v4l2_ioctl_ops {
 				    struct v4l2_format *f);
 	int (*vidioc_g_fmt_meta_cap)(struct file *file, void *fh,
 				     struct v4l2_format *f);
+	int (*vidioc_g_fmt_meta_out)(struct file *file, void *fh,
+				     struct v4l2_format *f);
 
 	/* VIDIOC_S_FMT handlers */
 	int (*vidioc_s_fmt_vid_cap)(struct file *file, void *fh,
@@ -373,6 +386,8 @@ struct v4l2_ioctl_ops {
 				    struct v4l2_format *f);
 	int (*vidioc_s_fmt_meta_cap)(struct file *file, void *fh,
 				     struct v4l2_format *f);
+	int (*vidioc_s_fmt_meta_out)(struct file *file, void *fh,
+				     struct v4l2_format *f);
 
 	/* VIDIOC_TRY_FMT handlers */
 	int (*vidioc_try_fmt_vid_cap)(struct file *file, void *fh,
@@ -401,6 +416,8 @@ struct v4l2_ioctl_ops {
 				      struct v4l2_format *f);
 	int (*vidioc_try_fmt_meta_cap)(struct file *file, void *fh,
 				       struct v4l2_format *f);
+	int (*vidioc_try_fmt_meta_out)(struct file *file, void *fh,
+				       struct v4l2_format *f);
 
 	/* Buffer handlers */
 	int (*vidioc_reqbufs)(struct file *file, void *fh,
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 45cf735..da17596 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -144,6 +144,7 @@ enum v4l2_buf_type {
 	V4L2_BUF_TYPE_SDR_CAPTURE          = 11,
 	V4L2_BUF_TYPE_SDR_OUTPUT           = 12,
 	V4L2_BUF_TYPE_META_CAPTURE         = 13,
+	V4L2_BUF_TYPE_META_OUTPUT	   = 14,
 	/* Deprecated, do not use */
 	V4L2_BUF_TYPE_PRIVATE              = 0x80,
 };
@@ -457,6 +458,7 @@ struct v4l2_capability {
 #define V4L2_CAP_READWRITE              0x01000000  /* read/write systemcalls */
 #define V4L2_CAP_ASYNCIO                0x02000000  /* async I/O */
 #define V4L2_CAP_STREAMING              0x04000000  /* streaming I/O ioctls */
+#define V4L2_CAP_META_OUTPUT		0x08000000  /* Is a metadata output device */
 
 #define V4L2_CAP_TOUCH                  0x10000000  /* Is a touch device */
 
-- 
2.7.4

[PATCH 2/2] docs-rst: v4l: Document V4L2_BUF_TYPE_META_OUTPUT interface

[Sakari Ailus]

Document the interface for metadata output, including
V4L2_BUF_TYPE_META_OUTPUT buffer type and V4L2_CAP_META_OUTPUT capability
bits.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 Documentation/media/uapi/v4l/buffer.rst          |  3 +++
 Documentation/media/uapi/v4l/dev-meta.rst        | 33 ++++++++++++++----------
 Documentation/media/uapi/v4l/vidioc-querycap.rst |  3 +++
 Documentation/media/videodev2.h.rst.exceptions   |  2 ++
 4 files changed, 28 insertions(+), 13 deletions(-)

diff --git a/Documentation/media/uapi/v4l/buffer.rst b/Documentation/media/uapi/v4l/buffer.rst
index ae6ee73..33b932e 100644
--- a/Documentation/media/uapi/v4l/buffer.rst
+++ b/Documentation/media/uapi/v4l/buffer.rst
@@ -452,6 +452,9 @@ enum v4l2_buf_type
     * - ``V4L2_BUF_TYPE_META_CAPTURE``
       - 13
       - Buffer for metadata capture, see :ref:`metadata`.
+    * - ``V4L2_BUF_TYPE_META_OUTPUT``
+      - 14
+      - Buffer for metadata output, see :ref:`metadata`.
 
 
 
diff --git a/Documentation/media/uapi/v4l/dev-meta.rst b/Documentation/media/uapi/v4l/dev-meta.rst
index 62518ad..a1e54bc 100644
--- a/Documentation/media/uapi/v4l/dev-meta.rst
+++ b/Documentation/media/uapi/v4l/dev-meta.rst
@@ -7,21 +7,27 @@ Metadata Interface
 ******************
 
 Metadata refers to any non-image data that supplements video frames with
-additional information. This may include statistics computed over the image
-or frame capture parameters supplied by the image source. This interface is
-intended for transfer of metadata to userspace and control of that operation.
+additional information. This may include statistics computed over the image,
+frame capture parameters supplied by the image source or device specific
+parameters for specifying how the device processes images. This interface is
+intended for transfer of metadata between the userspace and the hardware and
+control of that operation.
 
-The metadata interface is implemented on video capture device nodes. The device
-can be dedicated to metadata or can implement both video and metadata capture
-as specified in its reported capabilities.
+The metadata interface is implemented on video device nodes. The device can be
+dedicated to metadata or can support both video and metadata as specified in its
+reported capabilities.
 
 Querying Capabilities
 =====================
 
-Device nodes supporting the metadata interface set the ``V4L2_CAP_META_CAPTURE``
-flag in the ``device_caps`` field of the
+Device nodes supporting the metadata capture interface set the
+``V4L2_CAP_META_CAPTURE`` flag in the ``device_caps`` field of the
 :c:type:`v4l2_capability` structure returned by the :c:func:`VIDIOC_QUERYCAP`
-ioctl. That flag means the device can capture metadata to memory.
+ioctl. That flag means the device can capture metadata to memory. Similarly,
+device nodes supporting metadata output interface set the
+``V4L2_CAP_META_OUTPUT`` flag in the ``device_caps`` field of
+:c:type:`v4l2_capability` structure. That flag means the device can read
+metadata from memory.
 
 At least one of the read/write or streaming I/O methods must be supported.
 
@@ -35,10 +41,11 @@ to the basic :ref:`format` ioctls, the :c:func:`VIDIOC_ENUM_FMT` ioctl must be
 supported as well.
 
 To use the :ref:`format` ioctls applications set the ``type`` field of the
-:c:type:`v4l2_format` structure to ``V4L2_BUF_TYPE_META_CAPTURE`` and use the
-:c:type:`v4l2_meta_format` ``meta`` member of the ``fmt`` union as needed per
-the desired operation. Both drivers and applications must set the remainder of
-the :c:type:`v4l2_format` structure to 0.
+:c:type:`v4l2_format` structure to ``V4L2_BUF_TYPE_META_CAPTURE`` or to
+``V4L2_BUF_TYPE_META_OUTPUT`` and use the :c:type:`v4l2_meta_format` ``meta``
+member of the ``fmt`` union as needed per the desired operation. Both drivers
+and applications must set the remainder of the :c:type:`v4l2_format` structure
+to 0.
 
 .. _v4l2-meta-format:
 
diff --git a/Documentation/media/uapi/v4l/vidioc-querycap.rst b/Documentation/media/uapi/v4l/vidioc-querycap.rst
index 12e0d9a..36bf879 100644
--- a/Documentation/media/uapi/v4l/vidioc-querycap.rst
+++ b/Documentation/media/uapi/v4l/vidioc-querycap.rst
@@ -249,6 +249,9 @@ specification the ioctl returns an ``EINVAL`` error code.
     * - ``V4L2_CAP_STREAMING``
       - 0x04000000
       - The device supports the :ref:`streaming <mmap>` I/O method.
+    * - ``V4L2_CAP_META_OUTPUT``
+      - 0x08000000
+      - The device supports the :ref:`metadata` output interface.
     * - ``V4L2_CAP_TOUCH``
       - 0x10000000
       - This is a touch device.
diff --git a/Documentation/media/videodev2.h.rst.exceptions b/Documentation/media/videodev2.h.rst.exceptions
index a5cb0a8..32172db 100644
--- a/Documentation/media/videodev2.h.rst.exceptions
+++ b/Documentation/media/videodev2.h.rst.exceptions
@@ -28,6 +28,7 @@ replace symbol V4L2_FIELD_TOP :c:type:`v4l2_field`
 
 # Documented enum v4l2_buf_type
 replace symbol V4L2_BUF_TYPE_META_CAPTURE :c:type:`v4l2_buf_type`
+replace symbol V4L2_BUF_TYPE_META_OUTPUT :c:type:`v4l2_buf_type`
 replace symbol V4L2_BUF_TYPE_SDR_CAPTURE :c:type:`v4l2_buf_type`
 replace symbol V4L2_BUF_TYPE_SDR_OUTPUT :c:type:`v4l2_buf_type`
 replace symbol V4L2_BUF_TYPE_SLICED_VBI_CAPTURE :c:type:`v4l2_buf_type`
@@ -157,6 +158,7 @@ replace define V4L2_CAP_META_CAPTURE device-capabilities
 replace define V4L2_CAP_READWRITE device-capabilities
 replace define V4L2_CAP_ASYNCIO device-capabilities
 replace define V4L2_CAP_STREAMING device-capabilities
+replace define V4L2_CAP_META_OUTPUT device-capabilities
 replace define V4L2_CAP_DEVICE_CAPS device-capabilities
 replace define V4L2_CAP_TOUCH device-capabilities
 
-- 
2.7.4

Re: [PATCH 0/2] Add V4L2_BUF_TYPE_META_OUTPUT buffer type

[Tomasz Figa]

Hi Sakari,

On Sat, Aug 19, 2017 at 6:30 AM, Sakari Ailus
<sakari.ailus@linux.intel.com> wrote:
> Hi folks,
>
> Here's a non-RFC version of the META_OUTPUT buffer type patches.
>
> The V4L2_BUF_TYPE_META_OUTPUT buffer type complements the metadata buffer
> types support for OUTPUT buffers, capture being already supported. This is
> intended for similar cases than V4L2_BUF_TYPE_META_CAPTURE but for output
> buffers, e.g. device parameters that may be complex and highly
> hierarchical data structure. Statistics are a current use case for
> metadata capture buffers.
>
> Yong: could you take these to your IPU3 ImgU patchset, please? As that
> would be the first user, the patches would be merged with the driver
> itself.
>
> since RFC:
>
> - Fix make htmldocs build.
>
> - Fix CAPTURE -> OUTPUT in buffer.rst.
>
> - Added " for specifying how the device processes images" in the
>   documentation.
>
> Sakari Ailus (2):
>   v4l: Add support for V4L2_BUF_TYPE_META_OUTPUT
>   docs-rst: v4l: Document V4L2_BUF_TYPE_META_OUTPUT interface
>
>  Documentation/media/uapi/v4l/buffer.rst          |  3 +++
>  Documentation/media/uapi/v4l/dev-meta.rst        | 33 ++++++++++++++----------
>  Documentation/media/uapi/v4l/vidioc-querycap.rst |  3 +++
>  Documentation/media/videodev2.h.rst.exceptions   |  2 ++
>  drivers/media/v4l2-core/v4l2-compat-ioctl32.c    |  2 ++
>  drivers/media/v4l2-core/v4l2-ioctl.c             | 25 ++++++++++++++++++
>  drivers/media/v4l2-core/videobuf2-v4l2.c         |  1 +
>  include/media/v4l2-ioctl.h                       | 17 ++++++++++++
>  include/uapi/linux/videodev2.h                   |  2 ++
>  9 files changed, 75 insertions(+), 13 deletions(-)

For the whole series:
Reviewed-by: Tomasz Figa <tfiga@chromium.org>

Best regards,
Tomasz

RE: [PATCH 0/2] Add V4L2_BUF_TYPE_META_OUTPUT buffer type

[Zhi, Yong]

Hi, Sakari,

> -----Original Message-----
> From: Sakari Ailus [mailto:sakari.ailus-VuQAYsv1563Yd54FQh9/CA@public.gmane.org]
> Sent: Friday, August 18, 2017 2:31 PM
> To: linux-media-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> Cc: linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; tfiga-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org; Zhi, Yong
> <yong.zhi-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> Subject: [PATCH 0/2] Add V4L2_BUF_TYPE_META_OUTPUT buffer type
> 
> Hi folks,
> 
> Here's a non-RFC version of the META_OUTPUT buffer type patches.
> 
> The V4L2_BUF_TYPE_META_OUTPUT buffer type complements the metadata
> buffer types support for OUTPUT buffers, capture being already supported.
> This is intended for similar cases than V4L2_BUF_TYPE_META_CAPTURE but
> for output buffers, e.g. device parameters that may be complex and highly
> hierarchical data structure. Statistics are a current use case for metadata
> capture buffers.
> 
> Yong: could you take these to your IPU3 ImgU patchset, please? As that
> would be the first user, the patches would be merged with the driver itself.
> 

We implemented the meta format support in IPU3, the changes will be in ImgU v4, thanks!!

> since RFC:
> 
> - Fix make htmldocs build.
> 
> - Fix CAPTURE -> OUTPUT in buffer.rst.
> 
> - Added " for specifying how the device processes images" in the
>   documentation.
> 
> Sakari Ailus (2):
>   v4l: Add support for V4L2_BUF_TYPE_META_OUTPUT
>   docs-rst: v4l: Document V4L2_BUF_TYPE_META_OUTPUT interface
> 
>  Documentation/media/uapi/v4l/buffer.rst          |  3 +++
>  Documentation/media/uapi/v4l/dev-meta.rst        | 33 ++++++++++++++------
> ----
>  Documentation/media/uapi/v4l/vidioc-querycap.rst |  3 +++
>  Documentation/media/videodev2.h.rst.exceptions   |  2 ++
>  drivers/media/v4l2-core/v4l2-compat-ioctl32.c    |  2 ++
>  drivers/media/v4l2-core/v4l2-ioctl.c             | 25 ++++++++++++++++++
>  drivers/media/v4l2-core/videobuf2-v4l2.c         |  1 +
>  include/media/v4l2-ioctl.h                       | 17 ++++++++++++
>  include/uapi/linux/videodev2.h                   |  2 ++
>  9 files changed, 75 insertions(+), 13 deletions(-)
> 
> --
> 2.7.4