From 35c3017a29d278c4405a7f3ab30b814999d156d3 Mon Sep 17 00:00:00 2001 From: Laurent Pinchart Date: Wed, 5 May 2010 11:38:35 -0300 Subject: [media] v4l: v4l2_subdev userspace frame interval API The three new ioctl VIDIOC_SUBDEV_ENUM_FRAME_INTERVAL, VIDIOC_SUBDEV_G_FRAME_INTERVAL and VIDIOC_SUBDEV_S_FRAME_INTERVAL can be used to enumerate and configure a subdev's frame rate from userspace. Two new video::g/s_frame_interval subdev operations are introduced to support those ioctls. The existing video::g/s_parm operations are deprecated and shouldn't be used anymore. Signed-off-by: Laurent Pinchart Signed-off-by: Sakari Ailus Acked-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- Documentation/DocBook/media-entities.tmpl | 6 + Documentation/DocBook/v4l/v4l2.xml | 2 + .../v4l/vidioc-subdev-enum-frame-interval.xml | 152 +++++++++++++++++++++ .../DocBook/v4l/vidioc-subdev-g-frame-interval.xml | 141 +++++++++++++++++++ 4 files changed, 301 insertions(+) create mode 100644 Documentation/DocBook/v4l/vidioc-subdev-enum-frame-interval.xml create mode 100644 Documentation/DocBook/v4l/vidioc-subdev-g-frame-interval.xml (limited to 'Documentation') diff --git a/Documentation/DocBook/media-entities.tmpl b/Documentation/DocBook/media-entities.tmpl index dbb9cb2..a95eb57 100644 --- a/Documentation/DocBook/media-entities.tmpl +++ b/Documentation/DocBook/media-entities.tmpl @@ -89,7 +89,9 @@ VIDIOC_SUBDEV_ENUM_FRAME_SIZE"> VIDIOC_SUBDEV_ENUM_MBUS_CODE"> VIDIOC_SUBDEV_G_FMT"> +VIDIOC_SUBDEV_G_FRAME_INTERVAL"> VIDIOC_SUBDEV_S_FMT"> +VIDIOC_SUBDEV_S_FRAME_INTERVAL"> VIDIOC_TRY_ENCODER_CMD"> VIDIOC_TRY_EXT_CTRLS"> VIDIOC_TRY_FMT"> @@ -193,6 +195,8 @@ v4l2_sliced_vbi_cap"> v4l2_sliced_vbi_data"> v4l2_sliced_vbi_format"> +v4l2_subdev_frame_interval"> +v4l2_subdev_frame_interval_enum"> v4l2_subdev_frame_size_enum"> v4l2_subdev_format"> v4l2_subdev_mbus_code_enum"> @@ -331,10 +335,12 @@ + + diff --git a/Documentation/DocBook/v4l/v4l2.xml b/Documentation/DocBook/v4l/v4l2.xml index 2ada2f8..a436716 100644 --- a/Documentation/DocBook/v4l/v4l2.xml +++ b/Documentation/DocBook/v4l/v4l2.xml @@ -507,9 +507,11 @@ and discussions on the V4L mailing list. &sub-reqbufs; &sub-s-hw-freq-seek; &sub-streamon; + &sub-subdev-enum-frame-interval; &sub-subdev-enum-frame-size; &sub-subdev-enum-mbus-code; &sub-subdev-g-fmt; + &sub-subdev-g-frame-interval; &sub-subscribe-event; &sub-mmap; diff --git a/Documentation/DocBook/v4l/vidioc-subdev-enum-frame-interval.xml b/Documentation/DocBook/v4l/vidioc-subdev-enum-frame-interval.xml new file mode 100644 index 0000000..2f8f4f0 --- /dev/null +++ b/Documentation/DocBook/v4l/vidioc-subdev-enum-frame-interval.xml @@ -0,0 +1,152 @@ + + + ioctl VIDIOC_SUBDEV_ENUM_FRAME_INTERVAL + &manvol; + + + + VIDIOC_SUBDEV_ENUM_FRAME_INTERVAL + Enumerate frame intervals + + + + + + int ioctl + int fd + int request + struct v4l2_subdev_frame_interval_enum * + argp + + + + + + Arguments + + + + fd + + &fd; + + + + request + + VIDIOC_SUBDEV_ENUM_FRAME_INTERVAL + + + + argp + + + + + + + + + Description + + + Experimental + This is an experimental + interface and may change in the future. + + + This ioctl lets applications enumerate available frame intervals on a + given sub-device pad. Frame intervals only makes sense for sub-devices that + can control the frame period on their own. This includes, for instance, + image sensors and TV tuners. + + For the common use case of image sensors, the frame intervals + available on the sub-device output pad depend on the frame format and size + on the same pad. Applications must thus specify the desired format and size + when enumerating frame intervals. + + To enumerate frame intervals applications initialize the + index, pad, + code, width and + height fields of + &v4l2-subdev-frame-interval-enum; and call the + VIDIOC_SUBDEV_ENUM_FRAME_INTERVAL ioctl with a pointer + to this structure. Drivers fill the rest of the structure or return + an &EINVAL; if one of the input fields is invalid. All frame intervals are + enumerable by beginning at index zero and incrementing by one until + EINVAL is returned. + + Available frame intervals may depend on the current 'try' formats + at other pads of the sub-device, as well as on the current active links. See + &VIDIOC-SUBDEV-G-FMT; for more information about the try formats. + + Sub-devices that support the frame interval enumeration ioctl should + implemented it on a single pad only. Its behaviour when supported on + multiple pads of the same sub-device is not defined. + + + struct <structname>v4l2_subdev_frame_interval_enum</structname> + + &cs-str; + + + __u32 + index + Number of the format in the enumeration, set by the + application. + + + __u32 + pad + Pad number as reported by the media controller API. + + + __u32 + code + The media bus format code, as defined in + . + + + __u32 + width + Frame width, in pixels. + + + __u32 + height + Frame height, in pixels. + + + &v4l2-fract; + interval + Period, in seconds, between consecutive video frames. + + + __u32 + reserved[9] + Reserved for future extensions. Applications and drivers must + set the array to zero. + + + +
+ + + + &return-value; + + + + EINVAL + + The &v4l2-subdev-frame-interval-enum; + pad references a non-existing pad, one of + the code, width + or height fields are invalid for the given + pad or the index field is out of bounds. + + + + + + diff --git a/Documentation/DocBook/v4l/vidioc-subdev-g-frame-interval.xml b/Documentation/DocBook/v4l/vidioc-subdev-g-frame-interval.xml new file mode 100644 index 0000000..0bc3ea2 --- /dev/null +++ b/Documentation/DocBook/v4l/vidioc-subdev-g-frame-interval.xml @@ -0,0 +1,141 @@ + + + ioctl VIDIOC_SUBDEV_G_FRAME_INTERVAL, VIDIOC_SUBDEV_S_FRAME_INTERVAL + &manvol; + + + + VIDIOC_SUBDEV_G_FRAME_INTERVAL + VIDIOC_SUBDEV_S_FRAME_INTERVAL + Get or set the frame interval on a subdev pad + + + + + + int ioctl + int fd + int request + struct v4l2_subdev_frame_interval *argp + + + + + + + Arguments + + + + fd + + &fd; + + + + request + + VIDIOC_SUBDEV_G_FRAME_INTERVAL, VIDIOC_SUBDEV_S_FRAME_INTERVAL + + + + argp + + + + + + + + + Description + + + Experimental + This is an experimental + interface and may change in the future. + + + These ioctls are used to get and set the frame interval at specific + subdev pads in the image pipeline. The frame interval only makes sense for + sub-devices that can control the frame period on their own. This includes, + for instance, image sensors and TV tuners. Sub-devices that don't support + frame intervals must not implement these ioctls. + + To retrieve the current frame interval applications set the + pad field of a &v4l2-subdev-frame-interval; to + the desired pad number as reported by the media controller API. When they + call the VIDIOC_SUBDEV_G_FRAME_INTERVAL ioctl with a + pointer to this structure the driver fills the members of the + interval field. + + To change the current frame interval applications set both the + pad field and all members of the + interval field. When they call the + VIDIOC_SUBDEV_S_FRAME_INTERVAL ioctl with a pointer to + this structure the driver verifies the requested interval, adjusts it based + on the hardware capabilities and configures the device. Upon return the + &v4l2-subdev-frame-interval; contains the current frame interval as would be + returned by a VIDIOC_SUBDEV_G_FRAME_INTERVAL call. + + + Drivers must not return an error solely because the requested interval + doesn't match the device capabilities. They must instead modify the interval + to match what the hardware can provide. The modified interval should be as + close as possible to the original request. + + Sub-devices that support the frame interval ioctls should implement + them on a single pad only. Their behaviour when supported on multiple pads + of the same sub-device is not defined. + + + struct <structname>v4l2_subdev_frame_interval</structname> + + &cs-str; + + + __u32 + pad + Pad number as reported by the media controller API. + + + &v4l2-fract; + interval + Period, in seconds, between consecutive video frames. + + + __u32 + reserved[9] + Reserved for future extensions. Applications and drivers must + set the array to zero. + + + +
+ + + + &return-value; + + + + EBUSY + + The frame interval can't be changed because the pad is currently + busy. This can be caused, for instance, by an active video stream on + the pad. The ioctl must not be retried without performing another + action to fix the problem first. Only returned by + VIDIOC_SUBDEV_S_FRAME_INTERVAL + + + + EINVAL + + The &v4l2-subdev-frame-interval; pad + references a non-existing pad, or the pad doesn't support frame + intervals. + + + + + -- cgit v1.1