1 .. Permission is granted to copy, distribute and/or modify this
2 .. document under the terms of the GNU Free Documentation License,
3 .. Version 1.1 or any later version published by the Free Software
4 .. Foundation, with no Invariant Sections, no Front-Cover Texts
5 .. and no Back-Cover Texts. A copy of the license is included at
6 .. Documentation/media/uapi/fdl-appendix.rst.
8 .. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections
10 .. _v4l2-meta-fmt-d4xx:
12 *******************************
13 V4L2_META_FMT_D4XX ('D4XX')
14 *******************************
16 Intel D4xx UVC Cameras Metadata
22 Intel D4xx (D435 and other) cameras include per-frame metadata in their UVC
23 payload headers, following the Microsoft(R) UVC extension proposal [1_]. That
24 means, that the private D4XX metadata, following the standard UVC header, is
25 organised in blocks. D4XX cameras implement several standard block types,
26 proposed by Microsoft, and several proprietary ones. Supported standard metadata
27 types are MetadataId_CaptureStats (ID 3), MetadataId_CameraExtrinsics (ID 4),
28 and MetadataId_CameraIntrinsics (ID 5). For their description see [1_]. This
29 document describes proprietary metadata types, used by D4xx cameras.
31 V4L2_META_FMT_D4XX buffers follow the metadata buffer layout of
32 V4L2_META_FMT_UVC with the only difference, that it also includes proprietary
33 payload header data. D4xx cameras use bulk transfers and only send one payload
34 per frame, therefore their headers cannot be larger than 255 bytes.
36 Below are proprietary Microsoft style metadata types, used by D4xx cameras,
37 where all fields are in little endian order:
39 .. flat-table:: D4xx metadata
46 * - :cspan:`1` *Depth Control*
50 - Size in bytes (currently 56)
52 - Version of this structure. The documentation herein corresponds to
53 version xxx. The version number will be incremented when new fields are
56 - A bitmask of flags: see [2_] below
58 - Gain value in internal units, same as the V4L2_CID_GAIN control, used to
61 - Exposure time (in microseconds) used to capture the frame
63 - Power of the laser LED 0-360, used for depth measurement
65 - 0: manual; 1: automatic exposure
66 * - __u32 Exposure priority
67 - Exposure priority value: 0 - constant frame rate
69 - Left border of the AE Region of Interest (all ROI values are in pixels
70 and lie between 0 and maximum width or height respectively)
71 * - __u32 AE ROI right
72 - Right border of the AE Region of Interest
74 - Top border of the AE Region of Interest
75 * - __u32 AE ROI bottom
76 - Bottom border of the AE Region of Interest
78 - Preset selector value, default: 0, unless changed by the user
81 * - :cspan:`1` *Capture Timing*
85 - Size in bytes (currently 40)
87 - Version of this structure. The documentation herein corresponds to
88 version xxx. The version number will be incremented when new fields are
91 - A bitmask of flags: see [3_] below
92 * - __u32 Frame counter
93 - Monotonically increasing counter
94 * - __u32 Optical time
95 - Time in microseconds from the beginning of a frame till its middle
96 * - __u32 Readout time
97 - Time, used to read out a frame in microseconds
98 * - __u32 Exposure time
99 - Frame exposure time in microseconds
100 * - __u32 Frame interval
101 - In microseconds = 1000000 / framerate
102 * - __u32 Pipe latency
103 - Time in microseconds from start of frame to data in USB buffer
104 * - :cspan:`1` *Configuration*
108 - Size in bytes (currently 40)
110 - Version of this structure. The documentation herein corresponds to
111 version xxx. The version number will be incremented when new fields are
114 - A bitmask of flags: see [4_] below
115 * - __u8 Hardware type
116 - Camera hardware version [5_]
118 - Camera hardware configuration [6_]
120 - Internal synchronisation
122 - Image format code [7_]
128 - Requested frame rate per second
130 - Byte 0: bit 0: depth and RGB are synchronised, bit 1: external trigger
134 [1] https://docs.microsoft.com/en-us/windows-hardware/drivers/stream/uvc-extensions-1-5
138 [2] Depth Control flags specify which fields are valid: ::
142 0x00000004 Laser power
144 0x00000010 Exposure priority
150 [3] Capture Timing flags specify which fields are valid: ::
152 0x00000001 Frame counter
153 0x00000002 Optical time
154 0x00000004 Readout time
155 0x00000008 Exposure time
156 0x00000010 Frame interval
157 0x00000020 Pipe latency
161 [4] Configuration flags specify which fields are valid: ::
163 0x00000001 Hardware type
182 [6] 8-bit camera hardware configuration bitfield: ::
189 [2] depthIsActive - has a laser projector
191 [4] Inertial Measurement Unit (IMU) presence
195 [6] 0: a projector, 1: an LED
200 [7] Image format codes per video streaming interface: