The metadata buffer type is used to transfer metadata between userspace
and kernelspace through a V4L2 buffers queue. It comes with a new
metadata capture capability and format description.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
---
Documentation/DocBook/media/v4l/dev-meta.xml | 93 +++++++++++++++++++++++++++
Documentation/DocBook/media/v4l/v4l2.xml | 1 +
drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 19 ++++++
drivers/media/v4l2-core/v4l2-dev.c | 16 +++--
drivers/media/v4l2-core/v4l2-ioctl.c | 34 ++++++++++
drivers/media/v4l2-core/videobuf2-v4l2.c | 3 +
include/media/v4l2-ioctl.h | 8 +++
include/uapi/linux/videodev2.h | 14 ++++
8 files changed, 182 insertions(+), 6 deletions(-)
create mode 100644 Documentation/DocBook/media/v4l/dev-meta.xml
diff --git a/Documentation/DocBook/media/v4l/dev-meta.xml b/Documentation/DocBook/media/v4l/dev-meta.xml
new file mode 100644
index 000000000000..9b5b1fba2007
--- /dev/null
+++ b/Documentation/DocBook/media/v4l/dev-meta.xml
@@ -0,0 +1,93 @@
+ <title>Metadata Interface</title>
+
+ <note>
+ <title>Experimental</title>
+ <para>This is an <link linkend="experimental"> experimental </link>
+ interface and may change in the future.</para>
+ </note>
+
+ <para>
+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.
+ </para>
+
+ <para>
+The metadata interface is implemented on video capture devices. The device can
+be dedicated to metadata or can implement both video and metadata capture as
+specified in its reported capabilities.
+ </para>
+
+ <section>
+ <title>Querying Capabilities</title>
+
+ <para>
+Devices supporting the metadata interface set the
+<constant>V4L2_CAP_META_CAPTURE</constant> flag in the
+<structfield>capabilities</structfield> field of &v4l2-capability;
+returned by the &VIDIOC-QUERYCAP; ioctl. That flag means the device can capture
+metadata to memory.
+ </para>
+ <para>
+At least one of the read/write or streaming I/O methods must be supported.
+ </para>
+ </section>
+
+ <section>
+ <title>Data Format Negotiation</title>
+
+ <para>
+The metadata device uses the <link linkend="format">format</link> ioctls to
+select the capture format. The metadata buffer content format is bound to that
+selectable format. In addition to the basic
+<link linkend="format">format</link> ioctls, the &VIDIOC-ENUM-FMT; ioctl
+must be supported as well.
+ </para>
+
+ <para>
+To use the <link linkend="format">format</link> ioctls applications set the
+<structfield>type</structfield> field of a &v4l2-format; to
+<constant>V4L2_BUF_TYPE_META_CAPTURE</constant> and use the &v4l2-meta-format;
+<structfield>meta</structfield> member of the <structfield>fmt</structfield>
+union as needed per the desired operation.
+Currently there are two fields, <structfield>dataformat</structfield> and
+<structfield>buffersize</structfield>, of struct &v4l2-meta-format; that are
+used. Content of the <structfield>dataformat</structfield> is the V4L2 FourCC
+code of the data format. The <structfield>buffersize</structfield> field is the
+maximum buffer size in bytes required for data transfer, set by the driver in
+order to inform applications.
+ </para>
+
+ <table pgwide="1" frame="none" id="v4l2-meta-format">
+ <title>struct <structname>v4l2_meta_format</structname></title>
+ <tgroup cols="3">
+ &cs-str;
+ <tbody valign="top">
+ <row>
+ <entry>__u32</entry>
+ <entry><structfield>dataformat</structfield></entry>
+ <entry>
+The data format, set by the application. This is a little endian
+<link linkend="v4l2-fourcc">four character code</link>.
+V4L2 defines metadata formats in <xref linkend="meta-formats" />.
+ </entry>
+ </row>
+ <row>
+ <entry>__u32</entry>
+ <entry><structfield>buffersize</structfield></entry>
+ <entry>
+Maximum size in bytes required for data. Value is set by the driver.
+ </entry>
+ </row>
+ <row>
+ <entry>__u8</entry>
+ <entry><structfield>reserved[24]</structfield></entry>
+ <entry>This array is reserved for future extensions.
+Drivers and applications must set it to zero.</entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+
+ </section>
diff --git a/Documentation/DocBook/media/v4l/v4l2.xml b/Documentation/DocBook/media/v4l/v4l2.xml
index 42e626d6c936..5c83b5d342dd 100644
--- a/Documentation/DocBook/media/v4l/v4l2.xml
+++ b/Documentation/DocBook/media/v4l/v4l2.xml
@@ -605,6 +605,7 @@ and discussions on the V4L mailing list.</revremark>
<section id="radio"> &sub-dev-radio; </section>
<section id="rds"> &sub-dev-rds; </section>
<section id="sdr"> &sub-dev-sdr; </section>
+ <section id="meta"> &sub-dev-meta; </section>
<section id="event"> &sub-dev-event; </section>
<section id="subdev"> &sub-dev-subdev; </section>
</chapter>
diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
index bacecbd68a6d..da2d836e8887 100644
--- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
+++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
@@ -161,6 +161,20 @@ static inline int put_v4l2_sdr_format(struct v4l2_sdr_format *kp, struct v4l2_sd
return 0;
}
+static inline int get_v4l2_meta_format(struct v4l2_meta_format *kp, struct v4l2_meta_format __user *up)
+{
+ if (copy_from_user(kp, up, sizeof(struct v4l2_meta_format)))
+ return -EFAULT;
+ return 0;
+}
+
+static inline int put_v4l2_meta_format(struct v4l2_meta_format *kp, struct v4l2_meta_format __user *up)
+{
+ if (copy_to_user(up, kp, sizeof(struct v4l2_meta_format)))
+ return -EFAULT;
+ return 0;
+}
+
struct v4l2_format32 {
__u32 type; /* enum v4l2_buf_type */
union {
@@ -170,6 +184,7 @@ struct v4l2_format32 {
struct v4l2_vbi_format vbi;
struct v4l2_sliced_vbi_format sliced;
struct v4l2_sdr_format sdr;
+ struct v4l2_meta_format meta;
__u8 raw_data[200]; /* user-defined */
} fmt;
};
@@ -216,6 +231,8 @@ static int __get_v4l2_format32(struct v4l2_format *kp, struct v4l2_format32 __us
case V4L2_BUF_TYPE_SDR_CAPTURE:
case V4L2_BUF_TYPE_SDR_OUTPUT:
return get_v4l2_sdr_format(&kp->fmt.sdr, &up->fmt.sdr);
+ case V4L2_BUF_TYPE_META_CAPTURE:
+ return get_v4l2_meta_format(&kp->fmt.meta, &up->fmt.meta);
default:
pr_info("compat_ioctl32: unexpected VIDIOC_FMT type %d\n",
kp->type);
@@ -263,6 +280,8 @@ static int __put_v4l2_format32(struct v4l2_format *kp, struct v4l2_format32 __us
case V4L2_BUF_TYPE_SDR_CAPTURE:
case V4L2_BUF_TYPE_SDR_OUTPUT:
return put_v4l2_sdr_format(&kp->fmt.sdr, &up->fmt.sdr);
+ case V4L2_BUF_TYPE_META_CAPTURE:
+ return put_v4l2_meta_format(&kp->fmt.meta, &up->fmt.meta);
default:
pr_info("compat_ioctl32: unexpected VIDIOC_FMT type %d\n",
kp->type);
diff --git a/drivers/media/v4l2-core/v4l2-dev.c b/drivers/media/v4l2-core/v4l2-dev.c
index 70b559d7ca80..74b79e60ac38 100644
--- a/drivers/media/v4l2-core/v4l2-dev.c
+++ b/drivers/media/v4l2-core/v4l2-dev.c
@@ -574,30 +574,34 @@ static void determine_valid_ioctls(struct video_device *vdev)
set_bit(_IOC_NR(VIDIOC_ENUM_FREQ_BANDS), valid_ioctls);
if (is_vid) {
- /* video specific ioctls */
+ /* video and metadata specific ioctls */
if ((is_rx && (ops->vidioc_enum_fmt_vid_cap ||
ops->vidioc_enum_fmt_vid_cap_mplane ||
- ops->vidioc_enum_fmt_vid_overlay)) ||
+ ops->vidioc_enum_fmt_vid_overlay ||
+ ops->vidioc_enum_fmt_meta_cap)) ||
(is_tx && (ops->vidioc_enum_fmt_vid_out ||
ops->vidioc_enum_fmt_vid_out_mplane)))
set_bit(_IOC_NR(VIDIOC_ENUM_FMT), valid_ioctls);
if ((is_rx && (ops->vidioc_g_fmt_vid_cap ||
ops->vidioc_g_fmt_vid_cap_mplane ||
- ops->vidioc_g_fmt_vid_overlay)) ||
+ ops->vidioc_g_fmt_vid_overlay ||
+ ops->vidioc_g_fmt_meta_cap)) ||
(is_tx && (ops->vidioc_g_fmt_vid_out ||
ops->vidioc_g_fmt_vid_out_mplane ||
ops->vidioc_g_fmt_vid_out_overlay)))
set_bit(_IOC_NR(VIDIOC_G_FMT), valid_ioctls);
if ((is_rx && (ops->vidioc_s_fmt_vid_cap ||
ops->vidioc_s_fmt_vid_cap_mplane ||
- ops->vidioc_s_fmt_vid_overlay)) ||
+ ops->vidioc_s_fmt_vid_overlay ||
+ ops->vidioc_s_fmt_meta_cap)) ||
(is_tx && (ops->vidioc_s_fmt_vid_out ||
ops->vidioc_s_fmt_vid_out_mplane ||
ops->vidioc_s_fmt_vid_out_overlay)))
set_bit(_IOC_NR(VIDIOC_S_FMT), valid_ioctls);
if ((is_rx && (ops->vidioc_try_fmt_vid_cap ||
ops->vidioc_try_fmt_vid_cap_mplane ||
- ops->vidioc_try_fmt_vid_overlay)) ||
+ ops->vidioc_try_fmt_vid_overlay ||
+ ops->vidioc_try_fmt_meta_cap)) ||
(is_tx && (ops->vidioc_try_fmt_vid_out ||
ops->vidioc_try_fmt_vid_out_mplane ||
ops->vidioc_try_fmt_vid_out_overlay)))
@@ -663,7 +667,7 @@ static void determine_valid_ioctls(struct video_device *vdev)
}
if (is_vid || is_vbi || is_sdr) {
- /* ioctls valid for video, vbi or sdr */
+ /* ioctls valid for video, metadata, vbi or sdr */
SET_VALID_IOCTL(ops, VIDIOC_REQBUFS, vidioc_reqbufs);
SET_VALID_IOCTL(ops, VIDIOC_QUERYBUF, vidioc_querybuf);
SET_VALID_IOCTL(ops, VIDIOC_QBUF, vidioc_qbuf);
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index 28e5be2c2eef..5d003152ff68 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -155,6 +155,7 @@ const char *v4l2_type_names[] = {
[V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE] = "vid-out-mplane",
[V4L2_BUF_TYPE_SDR_CAPTURE] = "sdr-cap",
[V4L2_BUF_TYPE_SDR_OUTPUT] = "sdr-out",
+ [V4L2_BUF_TYPE_META_CAPTURE] = "meta-cap",
};
EXPORT_SYMBOL(v4l2_type_names);
@@ -249,6 +250,7 @@ static void v4l_print_format(const void *arg, bool write_only)
const struct v4l2_sliced_vbi_format *sliced;
const struct v4l2_window *win;
const struct v4l2_sdr_format *sdr;
+ const struct v4l2_meta_format *meta;
unsigned i;
pr_cont("type=%s", prt_names(p->type, v4l2_type_names));
@@ -336,6 +338,15 @@ static void v4l_print_format(const void *arg, bool write_only)
(sdr->pixelformat >> 16) & 0xff,
(sdr->pixelformat >> 24) & 0xff);
break;
+ case V4L2_BUF_TYPE_META_CAPTURE:
+ meta = &p->fmt.meta;
+ pr_cont(", dataformat=%c%c%c%c, buffersize=%u\n",
+ (meta->dataformat >> 0) & 0xff,
+ (meta->dataformat >> 8) & 0xff,
+ (meta->dataformat >> 16) & 0xff,
+ (meta->dataformat >> 24) & 0xff,
+ meta->buffersize);
+ break;
}
}
@@ -981,6 +992,10 @@ static int check_fmt(struct file *file, enum v4l2_buf_type type)
if (is_sdr && is_tx && ops->vidioc_g_fmt_sdr_out)
return 0;
break;
+ case V4L2_BUF_TYPE_META_CAPTURE:
+ if (is_vid && is_rx && ops->vidioc_g_fmt_meta_cap)
+ return 0;
+ break;
default:
break;
}
@@ -1349,6 +1364,11 @@ static int v4l_enum_fmt(const struct v4l2_ioctl_ops *ops,
break;
ret = ops->vidioc_enum_fmt_sdr_out(file, fh, arg);
break;
+ case V4L2_BUF_TYPE_META_CAPTURE:
+ if (unlikely(!is_rx || !is_vid || !ops->vidioc_enum_fmt_meta_cap))
+ break;
+ ret = ops->vidioc_enum_fmt_meta_cap(file, fh, arg);
+ break;
}
if (ret == 0)
v4l_fill_fmtdesc(p);
@@ -1447,6 +1467,10 @@ static int v4l_g_fmt(const struct v4l2_ioctl_ops *ops,
if (unlikely(!is_tx || !is_sdr || !ops->vidioc_g_fmt_sdr_out))
break;
return ops->vidioc_g_fmt_sdr_out(file, fh, arg);
+ case V4L2_BUF_TYPE_META_CAPTURE:
+ if (unlikely(!is_rx || !is_vid || !ops->vidioc_g_fmt_meta_cap))
+ break;
+ return ops->vidioc_g_fmt_meta_cap(file, fh, arg);
}
return -EINVAL;
}
@@ -1534,6 +1558,11 @@ static int v4l_s_fmt(const struct v4l2_ioctl_ops *ops,
break;
CLEAR_AFTER_FIELD(p, fmt.sdr);
return ops->vidioc_s_fmt_sdr_out(file, fh, arg);
+ case V4L2_BUF_TYPE_META_CAPTURE:
+ if (unlikely(!is_rx || !is_vid || !ops->vidioc_s_fmt_meta_cap))
+ break;
+ CLEAR_AFTER_FIELD(p, fmt.meta);
+ return ops->vidioc_s_fmt_meta_cap(file, fh, arg);
}
return -EINVAL;
}
@@ -1618,6 +1647,11 @@ static int v4l_try_fmt(const struct v4l2_ioctl_ops *ops,
break;
CLEAR_AFTER_FIELD(p, fmt.sdr);
return ops->vidioc_try_fmt_sdr_out(file, fh, arg);
+ case V4L2_BUF_TYPE_META_CAPTURE:
+ if (unlikely(!is_rx || !is_vid || !ops->vidioc_try_fmt_meta_cap))
+ break;
+ CLEAR_AFTER_FIELD(p, fmt.meta);
+ return ops->vidioc_try_fmt_meta_cap(file, fh, arg);
}
return -EINVAL;
}
diff --git a/drivers/media/v4l2-core/videobuf2-v4l2.c b/drivers/media/v4l2-core/videobuf2-v4l2.c
index 7f366f1b0377..e4e90d9a3a65 100644
--- a/drivers/media/v4l2-core/videobuf2-v4l2.c
+++ b/drivers/media/v4l2-core/videobuf2-v4l2.c
@@ -575,6 +575,9 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
case V4L2_BUF_TYPE_SDR_OUTPUT:
requested_sizes[0] = f->fmt.sdr.buffersize;
break;
+ case V4L2_BUF_TYPE_META_CAPTURE:
+ requested_sizes[0] = f->fmt.meta.buffersize;
+ break;
default:
return -EINVAL;
}
diff --git a/include/media/v4l2-ioctl.h b/include/media/v4l2-ioctl.h
index 017ffb2220c7..2dd00c73e892 100644
--- a/include/media/v4l2-ioctl.h
+++ b/include/media/v4l2-ioctl.h
@@ -38,6 +38,8 @@ struct v4l2_ioctl_ops {
struct v4l2_fmtdesc *f);
int (*vidioc_enum_fmt_sdr_out) (struct file *file, void *fh,
struct v4l2_fmtdesc *f);
+ int (*vidioc_enum_fmt_meta_cap) (struct file *file, void *fh,
+ struct v4l2_fmtdesc *f);
/* VIDIOC_G_FMT handlers */
int (*vidioc_g_fmt_vid_cap) (struct file *file, void *fh,
@@ -64,6 +66,8 @@ struct v4l2_ioctl_ops {
struct v4l2_format *f);
int (*vidioc_g_fmt_sdr_out) (struct file *file, void *fh,
struct v4l2_format *f);
+ int (*vidioc_g_fmt_meta_cap) (struct file *file, void *fh,
+ struct v4l2_format *f);
/* VIDIOC_S_FMT handlers */
int (*vidioc_s_fmt_vid_cap) (struct file *file, void *fh,
@@ -90,6 +94,8 @@ struct v4l2_ioctl_ops {
struct v4l2_format *f);
int (*vidioc_s_fmt_sdr_out) (struct file *file, void *fh,
struct v4l2_format *f);
+ int (*vidioc_s_fmt_meta_cap) (struct file *file, void *fh,
+ struct v4l2_format *f);
/* VIDIOC_TRY_FMT handlers */
int (*vidioc_try_fmt_vid_cap) (struct file *file, void *fh,
@@ -116,6 +122,8 @@ struct v4l2_ioctl_ops {
struct v4l2_format *f);
int (*vidioc_try_fmt_sdr_out) (struct file *file, void *fh,
struct v4l2_format *f);
+ int (*vidioc_try_fmt_meta_cap) (struct file *file, void *fh,
+ struct v4l2_format *f);
/* Buffer handlers */
int (*vidioc_reqbufs) (struct file *file, void *fh, struct v4l2_requestbuffers *b);
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 8f951917be74..5fbd30ca9b1e 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -143,6 +143,7 @@ enum v4l2_buf_type {
V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE = 10,
V4L2_BUF_TYPE_SDR_CAPTURE = 11,
V4L2_BUF_TYPE_SDR_OUTPUT = 12,
+ V4L2_BUF_TYPE_META_CAPTURE = 13,
/* Deprecated, do not use */
V4L2_BUF_TYPE_PRIVATE = 0x80,
};
@@ -435,6 +436,7 @@ struct v4l2_capability {
#define V4L2_CAP_SDR_CAPTURE 0x00100000 /* Is a SDR capture device */
#define V4L2_CAP_EXT_PIX_FORMAT 0x00200000 /* Supports the extended pixel format */
#define V4L2_CAP_SDR_OUTPUT 0x00400000 /* Is a SDR output device */
+#define V4L2_CAP_META_CAPTURE 0x00800000 /* Is a metadata capture device */
#define V4L2_CAP_READWRITE 0x01000000 /* read/write systemcalls */
#define V4L2_CAP_ASYNCIO 0x02000000 /* async I/O */
@@ -2000,6 +2002,17 @@ struct v4l2_sdr_format {
} __attribute__ ((packed));
/**
+ * struct v4l2_meta_format - metadata format definition
+ * @dataformat: little endian four character code (fourcc)
+ * @buffersize: maximum size in bytes required for data
+ */
+struct v4l2_meta_format {
+ __u32 dataformat;
+ __u32 buffersize;
+ __u8 reserved[24];
+} __attribute__ ((packed));
+
+/**
* struct v4l2_format - stream data format
* @type: enum v4l2_buf_type; type of the data stream
* @pix: definition of an image format
@@ -2018,6 +2031,7 @@ struct v4l2_format {
struct v4l2_vbi_format vbi; /* V4L2_BUF_TYPE_VBI_CAPTURE */
struct v4l2_sliced_vbi_format sliced; /* V4L2_BUF_TYPE_SLICED_VBI_CAPTURE */
struct v4l2_sdr_format sdr; /* V4L2_BUF_TYPE_SDR_CAPTURE */
+ struct v4l2_meta_format meta; /* V4L2_BUF_TYPE_META_CAPTURE */
__u8 raw_data[200]; /* user-defined */
} fmt;
};
--
Regards,
Laurent Pinchart
--
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