1 .. SPDX-License-Identifier: GPL-2.0 1 .. SPDX-License-Identifier: GPL-2.0
2 2
3 .. include:: <isonum.txt> 3 .. include:: <isonum.txt>
4 4
5 ============================================== 5 ===============================================================
6 Intel Image Processing Unit 3 (IPU3) Imaging U 6 Intel Image Processing Unit 3 (IPU3) Imaging Unit (ImgU) driver
7 ============================================== 7 ===============================================================
8 8
9 Copyright |copy| 2018 Intel Corporation 9 Copyright |copy| 2018 Intel Corporation
10 10
11 Introduction 11 Introduction
12 ============ 12 ============
13 13
14 This file documents the Intel IPU3 (3rd genera 14 This file documents the Intel IPU3 (3rd generation Image Processing Unit)
15 Imaging Unit drivers located under drivers/med 15 Imaging Unit drivers located under drivers/media/pci/intel/ipu3 (CIO2) as well
16 as under drivers/staging/media/ipu3 (ImgU). 16 as under drivers/staging/media/ipu3 (ImgU).
17 17
18 The Intel IPU3 found in certain Kaby Lake (as 18 The Intel IPU3 found in certain Kaby Lake (as well as certain Sky Lake)
19 platforms (U/Y processor lines) is made up of 19 platforms (U/Y processor lines) is made up of two parts namely the Imaging Unit
20 (ImgU) and the CIO2 device (MIPI CSI2 receiver 20 (ImgU) and the CIO2 device (MIPI CSI2 receiver).
21 21
22 The CIO2 device receives the raw Bayer data fr 22 The CIO2 device receives the raw Bayer data from the sensors and outputs the
23 frames in a format that is specific to the IPU 23 frames in a format that is specific to the IPU3 (for consumption by the IPU3
24 ImgU). The CIO2 driver is available as drivers 24 ImgU). The CIO2 driver is available as drivers/media/pci/intel/ipu3/ipu3-cio2*
25 and is enabled through the CONFIG_VIDEO_IPU3_C 25 and is enabled through the CONFIG_VIDEO_IPU3_CIO2 config option.
26 26
27 The Imaging Unit (ImgU) is responsible for pro 27 The Imaging Unit (ImgU) is responsible for processing images captured
28 by the IPU3 CIO2 device. The ImgU driver sourc 28 by the IPU3 CIO2 device. The ImgU driver sources can be found under
29 drivers/staging/media/ipu3 directory. The driv 29 drivers/staging/media/ipu3 directory. The driver is enabled through the
30 CONFIG_VIDEO_IPU3_IMGU config option. 30 CONFIG_VIDEO_IPU3_IMGU config option.
31 31
32 The two driver modules are named ipu3_csi2 and 32 The two driver modules are named ipu3_csi2 and ipu3_imgu, respectively.
33 33
34 The drivers has been tested on Kaby Lake platf 34 The drivers has been tested on Kaby Lake platforms (U/Y processor lines).
35 35
36 Both of the drivers implement V4L2, Media Cont 36 Both of the drivers implement V4L2, Media Controller and V4L2 sub-device
37 interfaces. The IPU3 CIO2 driver supports came 37 interfaces. The IPU3 CIO2 driver supports camera sensors connected to the CIO2
38 MIPI CSI-2 interfaces through V4L2 sub-device 38 MIPI CSI-2 interfaces through V4L2 sub-device sensor drivers.
39 39
40 CIO2 40 CIO2
41 ==== 41 ====
42 42
43 The CIO2 is represented as a single V4L2 subde 43 The CIO2 is represented as a single V4L2 subdev, which provides a V4L2 subdev
44 interface to the user space. There is a video 44 interface to the user space. There is a video node for each CSI-2 receiver,
45 with a single media controller interface for t 45 with a single media controller interface for the entire device.
46 46
47 The CIO2 contains four independent capture cha 47 The CIO2 contains four independent capture channel, each with its own MIPI CSI-2
48 receiver and DMA engine. Each channel is model 48 receiver and DMA engine. Each channel is modelled as a V4L2 sub-device exposed
49 to userspace as a V4L2 sub-device node and has 49 to userspace as a V4L2 sub-device node and has two pads:
50 50
51 .. tabularcolumns:: |p{0.8cm}|p{4.0cm}|p{4.0cm 51 .. tabularcolumns:: |p{0.8cm}|p{4.0cm}|p{4.0cm}|
52 52
53 .. flat-table:: 53 .. flat-table::
54 :header-rows: 1 54 :header-rows: 1
55 55
56 * - Pad 56 * - Pad
57 - Direction 57 - Direction
58 - Purpose 58 - Purpose
59 59
60 * - 0 60 * - 0
61 - sink 61 - sink
62 - MIPI CSI-2 input, connected to the sen 62 - MIPI CSI-2 input, connected to the sensor subdev
63 63
64 * - 1 64 * - 1
65 - source 65 - source
66 - Raw video capture, connected to the V4 66 - Raw video capture, connected to the V4L2 video interface
67 67
68 The V4L2 video interfaces model the DMA engine 68 The V4L2 video interfaces model the DMA engines. They are exposed to userspace
69 as V4L2 video device nodes. 69 as V4L2 video device nodes.
70 70
71 Capturing frames in raw Bayer format 71 Capturing frames in raw Bayer format
72 ------------------------------------ 72 ------------------------------------
73 73
74 CIO2 MIPI CSI2 receiver is used to capture fra 74 CIO2 MIPI CSI2 receiver is used to capture frames (in packed raw Bayer format)
75 from the raw sensors connected to the CSI2 por 75 from the raw sensors connected to the CSI2 ports. The captured frames are used
76 as input to the ImgU driver. 76 as input to the ImgU driver.
77 77
78 Image processing using IPU3 ImgU requires tool 78 Image processing using IPU3 ImgU requires tools such as raw2pnm [#f1]_, and
79 yavta [#f2]_ due to the following unique requi 79 yavta [#f2]_ due to the following unique requirements and / or features specific
80 to IPU3. 80 to IPU3.
81 81
82 -- The IPU3 CSI2 receiver outputs the captured 82 -- The IPU3 CSI2 receiver outputs the captured frames from the sensor in packed
83 raw Bayer format that is specific to IPU3. 83 raw Bayer format that is specific to IPU3.
84 84
85 -- Multiple video nodes have to be operated si 85 -- Multiple video nodes have to be operated simultaneously.
86 86
87 Let us take the example of ov5670 sensor conne 87 Let us take the example of ov5670 sensor connected to CSI2 port 0, for a
88 2592x1944 image capture. 88 2592x1944 image capture.
89 89
90 Using the media controller APIs, the ov5670 se 90 Using the media controller APIs, the ov5670 sensor is configured to send
91 frames in packed raw Bayer format to IPU3 CSI2 91 frames in packed raw Bayer format to IPU3 CSI2 receiver.
92 92
93 .. code-block:: none 93 .. code-block:: none
94 94
95 # This example assumes /dev/media0 as the 95 # This example assumes /dev/media0 as the CIO2 media device
96 export MDEV=/dev/media0 96 export MDEV=/dev/media0
97 97
98 # and that ov5670 sensor is connected to i 98 # and that ov5670 sensor is connected to i2c bus 10 with address 0x36
99 export SDEV=$(media-ctl -d $MDEV -e "ov567 99 export SDEV=$(media-ctl -d $MDEV -e "ov5670 10-0036")
100 100
101 # Establish the link for the media devices 101 # Establish the link for the media devices using media-ctl [#f3]_
102 media-ctl -d $MDEV -l "ov5670:0 -> ipu3-cs 102 media-ctl -d $MDEV -l "ov5670:0 -> ipu3-csi2 0:0[1]"
103 103
104 # Set the format for the media devices 104 # Set the format for the media devices
105 media-ctl -d $MDEV -V "ov5670:0 [fmt:SGRBG 105 media-ctl -d $MDEV -V "ov5670:0 [fmt:SGRBG10/2592x1944]"
106 media-ctl -d $MDEV -V "ipu3-csi2 0:0 [fmt: 106 media-ctl -d $MDEV -V "ipu3-csi2 0:0 [fmt:SGRBG10/2592x1944]"
107 media-ctl -d $MDEV -V "ipu3-csi2 0:1 [fmt: 107 media-ctl -d $MDEV -V "ipu3-csi2 0:1 [fmt:SGRBG10/2592x1944]"
108 108
109 Once the media pipeline is configured, desired 109 Once the media pipeline is configured, desired sensor specific settings
110 (such as exposure and gain settings) can be se 110 (such as exposure and gain settings) can be set, using the yavta tool.
111 111
112 e.g 112 e.g
113 113
114 .. code-block:: none 114 .. code-block:: none
115 115
116 yavta -w 0x009e0903 444 $SDEV 116 yavta -w 0x009e0903 444 $SDEV
117 yavta -w 0x009e0913 1024 $SDEV 117 yavta -w 0x009e0913 1024 $SDEV
118 yavta -w 0x009e0911 2046 $SDEV 118 yavta -w 0x009e0911 2046 $SDEV
119 119
120 Once the desired sensor settings are set, fram 120 Once the desired sensor settings are set, frame captures can be done as below.
121 121
122 e.g 122 e.g
123 123
124 .. code-block:: none 124 .. code-block:: none
125 125
126 yavta --data-prefix -u -c10 -n5 -I -s2592x 126 yavta --data-prefix -u -c10 -n5 -I -s2592x1944 --file=/tmp/frame-#.bin \
127 -f IPU3_SGRBG10 $(media-ctl -d $MDEV 127 -f IPU3_SGRBG10 $(media-ctl -d $MDEV -e "ipu3-cio2 0")
128 128
129 With the above command, 10 frames are captured 129 With the above command, 10 frames are captured at 2592x1944 resolution, with
130 sGRBG10 format and output as IPU3_SGRBG10 form 130 sGRBG10 format and output as IPU3_SGRBG10 format.
131 131
132 The captured frames are available as /tmp/fram 132 The captured frames are available as /tmp/frame-#.bin files.
133 133
134 ImgU 134 ImgU
135 ==== 135 ====
136 136
137 The ImgU is represented as two V4L2 subdevs, e 137 The ImgU is represented as two V4L2 subdevs, each of which provides a V4L2
138 subdev interface to the user space. 138 subdev interface to the user space.
139 139
140 Each V4L2 subdev represents a pipe, which can 140 Each V4L2 subdev represents a pipe, which can support a maximum of 2 streams.
141 This helps to support advanced camera features 141 This helps to support advanced camera features like Continuous View Finder (CVF)
142 and Snapshot During Video(SDV). 142 and Snapshot During Video(SDV).
143 143
144 The ImgU contains two independent pipes, each 144 The ImgU contains two independent pipes, each modelled as a V4L2 sub-device
145 exposed to userspace as a V4L2 sub-device node 145 exposed to userspace as a V4L2 sub-device node.
146 146
147 Each pipe has two sink pads and three source p 147 Each pipe has two sink pads and three source pads for the following purpose:
148 148
149 .. tabularcolumns:: |p{0.8cm}|p{4.0cm}|p{4.0cm 149 .. tabularcolumns:: |p{0.8cm}|p{4.0cm}|p{4.0cm}|
150 150
151 .. flat-table:: 151 .. flat-table::
152 :header-rows: 1 152 :header-rows: 1
153 153
154 * - Pad 154 * - Pad
155 - Direction 155 - Direction
156 - Purpose 156 - Purpose
157 157
158 * - 0 158 * - 0
159 - sink 159 - sink
160 - Input raw video stream 160 - Input raw video stream
161 161
162 * - 1 162 * - 1
163 - sink 163 - sink
164 - Processing parameters 164 - Processing parameters
165 165
166 * - 2 166 * - 2
167 - source 167 - source
168 - Output processed video stream 168 - Output processed video stream
169 169
170 * - 3 170 * - 3
171 - source 171 - source
172 - Output viewfinder video stream 172 - Output viewfinder video stream
173 173
174 * - 4 174 * - 4
175 - source 175 - source
176 - 3A statistics 176 - 3A statistics
177 177
178 Each pad is connected to a corresponding V4L2 178 Each pad is connected to a corresponding V4L2 video interface, exposed to
179 userspace as a V4L2 video device node. 179 userspace as a V4L2 video device node.
180 180
181 Device operation 181 Device operation
182 ---------------- 182 ----------------
183 183
184 With ImgU, once the input video node ("ipu3-im 184 With ImgU, once the input video node ("ipu3-imgu 0/1":0, in
185 <entity>:<pad-number> format) is queued with b 185 <entity>:<pad-number> format) is queued with buffer (in packed raw Bayer
186 format), ImgU starts processing the buffer and 186 format), ImgU starts processing the buffer and produces the video output in YUV
187 format and statistics output on respective out 187 format and statistics output on respective output nodes. The driver is expected
188 to have buffers ready for all of parameter, ou 188 to have buffers ready for all of parameter, output and statistics nodes, when
189 input video node is queued with buffer. 189 input video node is queued with buffer.
190 190
191 At a minimum, all of input, main output, 3A st 191 At a minimum, all of input, main output, 3A statistics and viewfinder
192 video nodes should be enabled for IPU3 to star 192 video nodes should be enabled for IPU3 to start image processing.
193 193
194 Each ImgU V4L2 subdev has the following set of 194 Each ImgU V4L2 subdev has the following set of video nodes.
195 195
196 input, output and viewfinder video nodes 196 input, output and viewfinder video nodes
197 ---------------------------------------- 197 ----------------------------------------
198 198
199 The frames (in packed raw Bayer format specifi 199 The frames (in packed raw Bayer format specific to the IPU3) received by the
200 input video node is processed by the IPU3 Imag 200 input video node is processed by the IPU3 Imaging Unit and are output to 2 video
201 nodes, with each targeting a different purpose 201 nodes, with each targeting a different purpose (main output and viewfinder
202 output). 202 output).
203 203
204 Details onand the Bayer format specific to the 204 Details onand the Bayer format specific to the IPU3 can be found in
205 :ref:`v4l2-pix-fmt-ipu3-sbggr10`. 205 :ref:`v4l2-pix-fmt-ipu3-sbggr10`.
206 206
207 The driver supports V4L2 Video Capture Interfa 207 The driver supports V4L2 Video Capture Interface as defined at :ref:`devices`.
208 208
209 Only the multi-planar API is supported. More d 209 Only the multi-planar API is supported. More details can be found at
210 :ref:`planar-apis`. 210 :ref:`planar-apis`.
211 211
212 Parameters video node 212 Parameters video node
213 --------------------- 213 ---------------------
214 214
215 The parameters video node receives the ImgU al 215 The parameters video node receives the ImgU algorithm parameters that are used
216 to configure how the ImgU algorithms process t 216 to configure how the ImgU algorithms process the image.
217 217
218 Details on processing parameters specific to t 218 Details on processing parameters specific to the IPU3 can be found in
219 :ref:`v4l2-meta-fmt-params`. 219 :ref:`v4l2-meta-fmt-params`.
220 220
221 3A statistics video node 221 3A statistics video node
222 ------------------------ 222 ------------------------
223 223
224 3A statistics video node is used by the ImgU d 224 3A statistics video node is used by the ImgU driver to output the 3A (auto
225 focus, auto exposure and auto white balance) s 225 focus, auto exposure and auto white balance) statistics for the frames that are
226 being processed by the ImgU to user space appl 226 being processed by the ImgU to user space applications. User space applications
227 can use this statistics data to compute the de 227 can use this statistics data to compute the desired algorithm parameters for
228 the ImgU. 228 the ImgU.
229 229
230 Configuring the Intel IPU3 230 Configuring the Intel IPU3
231 ========================== 231 ==========================
232 232
233 The IPU3 ImgU pipelines can be configured usin 233 The IPU3 ImgU pipelines can be configured using the Media Controller, defined at
234 :ref:`media_controller`. 234 :ref:`media_controller`.
235 235
236 Running mode and firmware binary selection 236 Running mode and firmware binary selection
237 ------------------------------------------ 237 ------------------------------------------
238 238
239 ImgU works based on firmware, currently the Im 239 ImgU works based on firmware, currently the ImgU firmware support run 2 pipes
240 in time-sharing with single input frame data. 240 in time-sharing with single input frame data. Each pipe can run at certain mode
241 - "VIDEO" or "STILL", "VIDEO" mode is commonly 241 - "VIDEO" or "STILL", "VIDEO" mode is commonly used for video frames capture,
242 and "STILL" is used for still frame capture. H 242 and "STILL" is used for still frame capture. However, you can also select
243 "VIDEO" to capture still frames if you want to 243 "VIDEO" to capture still frames if you want to capture images with less system
244 load and power. For "STILL" mode, ImgU will tr 244 load and power. For "STILL" mode, ImgU will try to use smaller BDS factor and
245 output larger bayer frame for further YUV proc 245 output larger bayer frame for further YUV processing than "VIDEO" mode to get
246 high quality images. Besides, "STILL" mode nee 246 high quality images. Besides, "STILL" mode need XNR3 to do noise reduction,
247 hence "STILL" mode will need more power and me 247 hence "STILL" mode will need more power and memory bandwidth than "VIDEO" mode.
248 TNR will be enabled in "VIDEO" mode and bypass 248 TNR will be enabled in "VIDEO" mode and bypassed by "STILL" mode. ImgU is
249 running at "VIDEO" mode by default, the user c 249 running at "VIDEO" mode by default, the user can use v4l2 control
250 V4L2_CID_INTEL_IPU3_MODE (currently defined in 250 V4L2_CID_INTEL_IPU3_MODE (currently defined in
251 drivers/staging/media/ipu3/include/uapi/intel- 251 drivers/staging/media/ipu3/include/uapi/intel-ipu3.h) to query and set the
252 running mode. For user, there is no difference 252 running mode. For user, there is no difference for buffer queueing between the
253 "VIDEO" and "STILL" mode, mandatory input and 253 "VIDEO" and "STILL" mode, mandatory input and main output node should be
254 enabled and buffers need be queued, the statis 254 enabled and buffers need be queued, the statistics and the view-finder queues
255 are optional. 255 are optional.
256 256
257 The firmware binary will be selected according 257 The firmware binary will be selected according to current running mode, such log
258 "using binary if_to_osys_striped " or "using b 258 "using binary if_to_osys_striped " or "using binary if_to_osys_primary_striped"
259 could be observed if you enable the ImgU dynam 259 could be observed if you enable the ImgU dynamic debug, the binary
260 if_to_osys_striped is selected for "VIDEO" and 260 if_to_osys_striped is selected for "VIDEO" and the binary
261 "if_to_osys_primary_striped" is selected for " 261 "if_to_osys_primary_striped" is selected for "STILL".
262 262
263 263
264 Processing the image in raw Bayer format 264 Processing the image in raw Bayer format
265 ---------------------------------------- 265 ----------------------------------------
266 266
267 Configuring ImgU V4L2 subdev for image process 267 Configuring ImgU V4L2 subdev for image processing
268 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 268 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
269 269
270 The ImgU V4L2 subdevs have to be configured wi 270 The ImgU V4L2 subdevs have to be configured with media controller APIs to have
271 all the video nodes setup correctly. 271 all the video nodes setup correctly.
272 272
273 Let us take "ipu3-imgu 0" subdev as an example 273 Let us take "ipu3-imgu 0" subdev as an example.
274 274
275 .. code-block:: none 275 .. code-block:: none
276 276
277 media-ctl -d $MDEV -r 277 media-ctl -d $MDEV -r
278 media-ctl -d $MDEV -l "ipu3-imgu 0 input": 278 media-ctl -d $MDEV -l "ipu3-imgu 0 input":0 -> "ipu3-imgu 0":0[1]
279 media-ctl -d $MDEV -l "ipu3-imgu 0":2 -> " 279 media-ctl -d $MDEV -l "ipu3-imgu 0":2 -> "ipu3-imgu 0 output":0[1]
280 media-ctl -d $MDEV -l "ipu3-imgu 0":3 -> " 280 media-ctl -d $MDEV -l "ipu3-imgu 0":3 -> "ipu3-imgu 0 viewfinder":0[1]
281 media-ctl -d $MDEV -l "ipu3-imgu 0":4 -> " 281 media-ctl -d $MDEV -l "ipu3-imgu 0":4 -> "ipu3-imgu 0 3a stat":0[1]
282 282
283 Also the pipe mode of the corresponding V4L2 s 283 Also the pipe mode of the corresponding V4L2 subdev should be set as desired
284 (e.g 0 for video mode or 1 for still mode) thr 284 (e.g 0 for video mode or 1 for still mode) through the control id 0x009819a1 as
285 below. 285 below.
286 286
287 .. code-block:: none 287 .. code-block:: none
288 288
289 yavta -w "0x009819A1 1" /dev/v4l-subdev7 289 yavta -w "0x009819A1 1" /dev/v4l-subdev7
290 290
291 Certain hardware blocks in ImgU pipeline can c 291 Certain hardware blocks in ImgU pipeline can change the frame resolution by
292 cropping or scaling, these hardware blocks inc 292 cropping or scaling, these hardware blocks include Input Feeder(IF), Bayer Down
293 Scaler (BDS) and Geometric Distortion Correcti 293 Scaler (BDS) and Geometric Distortion Correction (GDC).
294 There is also a block which can change the fra 294 There is also a block which can change the frame resolution - YUV Scaler, it is
295 only applicable to the secondary output. 295 only applicable to the secondary output.
296 296
297 RAW Bayer frames go through these ImgU pipelin 297 RAW Bayer frames go through these ImgU pipeline hardware blocks and the final
298 processed image output to the DDR memory. 298 processed image output to the DDR memory.
299 299
300 .. kernel-figure:: ipu3_rcb.svg 300 .. kernel-figure:: ipu3_rcb.svg
301 :alt: ipu3 resolution blocks image 301 :alt: ipu3 resolution blocks image
302 302
303 IPU3 resolution change hardware blocks 303 IPU3 resolution change hardware blocks
304 304
305 **Input Feeder** 305 **Input Feeder**
306 306
307 Input Feeder gets the Bayer frame data from th 307 Input Feeder gets the Bayer frame data from the sensor, it can enable cropping
308 of lines and columns from the frame and then s 308 of lines and columns from the frame and then store pixels into device's internal
309 pixel buffer which are ready to readout by fol 309 pixel buffer which are ready to readout by following blocks.
310 310
311 **Bayer Down Scaler** 311 **Bayer Down Scaler**
312 312
313 Bayer Down Scaler is capable of performing ima 313 Bayer Down Scaler is capable of performing image scaling in Bayer domain, the
314 downscale factor can be configured from 1X to 314 downscale factor can be configured from 1X to 1/4X in each axis with
315 configuration steps of 0.03125 (1/32). 315 configuration steps of 0.03125 (1/32).
316 316
317 **Geometric Distortion Correction** 317 **Geometric Distortion Correction**
318 318
319 Geometric Distortion Correction is used to per 319 Geometric Distortion Correction is used to perform correction of distortions
320 and image filtering. It needs some extra filte 320 and image filtering. It needs some extra filter and envelope padding pixels to
321 work, so the input resolution of GDC should be 321 work, so the input resolution of GDC should be larger than the output
322 resolution. 322 resolution.
323 323
324 **YUV Scaler** 324 **YUV Scaler**
325 325
326 YUV Scaler which similar with BDS, but it is m 326 YUV Scaler which similar with BDS, but it is mainly do image down scaling in
327 YUV domain, it can support up to 1/12X down sc 327 YUV domain, it can support up to 1/12X down scaling, but it can not be applied
328 to the main output. 328 to the main output.
329 329
330 The ImgU V4L2 subdev has to be configured with 330 The ImgU V4L2 subdev has to be configured with the supported resolutions in all
331 the above hardware blocks, for a given input r 331 the above hardware blocks, for a given input resolution.
332 For a given supported resolution for an input 332 For a given supported resolution for an input frame, the Input Feeder, Bayer
333 Down Scaler and GDC blocks should be configure 333 Down Scaler and GDC blocks should be configured with the supported resolutions
334 as each hardware block has its own alignment r 334 as each hardware block has its own alignment requirement.
335 335
336 You must configure the output resolution of th 336 You must configure the output resolution of the hardware blocks smartly to meet
337 the hardware requirement along with keeping th 337 the hardware requirement along with keeping the maximum field of view. The
338 intermediate resolutions can be generated by s 338 intermediate resolutions can be generated by specific tool -
339 339
340 https://github.com/intel/intel-ipu3-pipecfg 340 https://github.com/intel/intel-ipu3-pipecfg
341 341
342 This tool can be used to generate intermediate 342 This tool can be used to generate intermediate resolutions. More information can
343 be obtained by looking at the following IPU3 I 343 be obtained by looking at the following IPU3 ImgU configuration table.
344 344
345 https://chromium.googlesource.com/chromiumos/o 345 https://chromium.googlesource.com/chromiumos/overlays/board-overlays/+/master
346 346
347 Under baseboard-poppy/media-libs/cros-camera-h 347 Under baseboard-poppy/media-libs/cros-camera-hal-configs-poppy/files/gcss
348 directory, graph_settings_ov5670.xml can be us 348 directory, graph_settings_ov5670.xml can be used as an example.
349 349
350 The following steps prepare the ImgU pipeline 350 The following steps prepare the ImgU pipeline for the image processing.
351 351
352 1. The ImgU V4L2 subdev data format should be 352 1. The ImgU V4L2 subdev data format should be set by using the
353 VIDIOC_SUBDEV_S_FMT on pad 0, using the GDC wi 353 VIDIOC_SUBDEV_S_FMT on pad 0, using the GDC width and height obtained above.
354 354
355 2. The ImgU V4L2 subdev cropping should be set 355 2. The ImgU V4L2 subdev cropping should be set by using the
356 VIDIOC_SUBDEV_S_SELECTION on pad 0, with V4L2_ 356 VIDIOC_SUBDEV_S_SELECTION on pad 0, with V4L2_SEL_TGT_CROP as the target,
357 using the input feeder height and width. 357 using the input feeder height and width.
358 358
359 3. The ImgU V4L2 subdev composing should be se 359 3. The ImgU V4L2 subdev composing should be set by using the
360 VIDIOC_SUBDEV_S_SELECTION on pad 0, with V4L2_ 360 VIDIOC_SUBDEV_S_SELECTION on pad 0, with V4L2_SEL_TGT_COMPOSE as the target,
361 using the BDS height and width. 361 using the BDS height and width.
362 362
363 For the ov5670 example, for an input frame wit 363 For the ov5670 example, for an input frame with a resolution of 2592x1944
364 (which is input to the ImgU subdev pad 0), the 364 (which is input to the ImgU subdev pad 0), the corresponding resolutions
365 for input feeder, BDS and GDC are 2592x1944, 2 365 for input feeder, BDS and GDC are 2592x1944, 2592x1944 and 2560x1920
366 respectively. 366 respectively.
367 367
368 Once this is done, the received raw Bayer fram 368 Once this is done, the received raw Bayer frames can be input to the ImgU
369 V4L2 subdev as below, using the open source ap 369 V4L2 subdev as below, using the open source application v4l2n [#f1]_.
370 370
371 For an image captured with 2592x1944 [#f4]_ re 371 For an image captured with 2592x1944 [#f4]_ resolution, with desired output
372 resolution as 2560x1920 and viewfinder resolut 372 resolution as 2560x1920 and viewfinder resolution as 2560x1920, the following
373 v4l2n command can be used. This helps process 373 v4l2n command can be used. This helps process the raw Bayer frames and produces
374 the desired results for the main output image 374 the desired results for the main output image and the viewfinder output, in NV12
375 format. 375 format.
376 376
377 .. code-block:: none 377 .. code-block:: none
378 378
379 v4l2n --pipe=4 --load=/tmp/frame-#.bin --o 379 v4l2n --pipe=4 --load=/tmp/frame-#.bin --open=/dev/video4
380 --fmt=type:VIDEO_OUTPUT_MPLANE,width 380 --fmt=type:VIDEO_OUTPUT_MPLANE,width=2592,height=1944,pixelformat=0X47337069 \
381 --reqbufs=type:VIDEO_OUTPUT_MPLANE,c 381 --reqbufs=type:VIDEO_OUTPUT_MPLANE,count:1 --pipe=1 \
382 --output=/tmp/frames.out --open=/dev 382 --output=/tmp/frames.out --open=/dev/video5 \
383 --fmt=type:VIDEO_CAPTURE_MPLANE,widt 383 --fmt=type:VIDEO_CAPTURE_MPLANE,width=2560,height=1920,pixelformat=NV12 \
384 --reqbufs=type:VIDEO_CAPTURE_MPLANE, 384 --reqbufs=type:VIDEO_CAPTURE_MPLANE,count:1 --pipe=2 \
385 --output=/tmp/frames.vf --open=/dev/ 385 --output=/tmp/frames.vf --open=/dev/video6 \
386 --fmt=type:VIDEO_CAPTURE_MPLANE,widt 386 --fmt=type:VIDEO_CAPTURE_MPLANE,width=2560,height=1920,pixelformat=NV12 \
387 --reqbufs=type:VIDEO_CAPTURE_MPLANE, 387 --reqbufs=type:VIDEO_CAPTURE_MPLANE,count:1 --pipe=3 --open=/dev/video7 \
388 --output=/tmp/frames.3A --fmt=type:M 388 --output=/tmp/frames.3A --fmt=type:META_CAPTURE,? \
389 --reqbufs=count:1,type:META_CAPTURE 389 --reqbufs=count:1,type:META_CAPTURE --pipe=1,2,3,4 --stream=5
390 390
391 You can also use yavta [#f2]_ command to do sa 391 You can also use yavta [#f2]_ command to do same thing as above:
392 392
393 .. code-block:: none 393 .. code-block:: none
394 394
395 yavta --data-prefix -Bcapture-mplane -c10 395 yavta --data-prefix -Bcapture-mplane -c10 -n5 -I -s2592x1944 \
396 --file=frame-#.out-f NV12 /dev/video 396 --file=frame-#.out-f NV12 /dev/video5 & \
397 yavta --data-prefix -Bcapture-mplane -c10 397 yavta --data-prefix -Bcapture-mplane -c10 -n5 -I -s2592x1944 \
398 --file=frame-#.vf -f NV12 /dev/video 398 --file=frame-#.vf -f NV12 /dev/video6 & \
399 yavta --data-prefix -Bmeta-capture -c10 -n 399 yavta --data-prefix -Bmeta-capture -c10 -n5 -I \
400 --file=frame-#.3a /dev/video7 & \ 400 --file=frame-#.3a /dev/video7 & \
401 yavta --data-prefix -Boutput-mplane -c10 - 401 yavta --data-prefix -Boutput-mplane -c10 -n5 -I -s2592x1944 \
402 --file=/tmp/frame-in.cio2 -f IPU3_SG 402 --file=/tmp/frame-in.cio2 -f IPU3_SGRBG10 /dev/video4
403 403
404 where /dev/video4, /dev/video5, /dev/video6 an 404 where /dev/video4, /dev/video5, /dev/video6 and /dev/video7 devices point to
405 input, output, viewfinder and 3A statistics vi 405 input, output, viewfinder and 3A statistics video nodes respectively.
406 406
407 Converting the raw Bayer image into YUV domain 407 Converting the raw Bayer image into YUV domain
408 ---------------------------------------------- 408 ----------------------------------------------
409 409
410 The processed images after the above step, can 410 The processed images after the above step, can be converted to YUV domain
411 as below. 411 as below.
412 412
413 Main output frames 413 Main output frames
414 ~~~~~~~~~~~~~~~~~~ 414 ~~~~~~~~~~~~~~~~~~
415 415
416 .. code-block:: none 416 .. code-block:: none
417 417
418 raw2pnm -x2560 -y1920 -fNV12 /tmp/frames.o 418 raw2pnm -x2560 -y1920 -fNV12 /tmp/frames.out /tmp/frames.out.ppm
419 419
420 where 2560x1920 is output resolution, NV12 is 420 where 2560x1920 is output resolution, NV12 is the video format, followed
421 by input frame and output PNM file. 421 by input frame and output PNM file.
422 422
423 Viewfinder output frames 423 Viewfinder output frames
424 ~~~~~~~~~~~~~~~~~~~~~~~~ 424 ~~~~~~~~~~~~~~~~~~~~~~~~
425 425
426 .. code-block:: none 426 .. code-block:: none
427 427
428 raw2pnm -x2560 -y1920 -fNV12 /tmp/frames.v 428 raw2pnm -x2560 -y1920 -fNV12 /tmp/frames.vf /tmp/frames.vf.ppm
429 429
430 where 2560x1920 is output resolution, NV12 is 430 where 2560x1920 is output resolution, NV12 is the video format, followed
431 by input frame and output PNM file. 431 by input frame and output PNM file.
432 432
433 Example user space code for IPU3 433 Example user space code for IPU3
434 ================================ 434 ================================
435 435
436 User space code that configures and uses IPU3 436 User space code that configures and uses IPU3 is available here.
437 437
438 https://chromium.googlesource.com/chromiumos/p 438 https://chromium.googlesource.com/chromiumos/platform/arc-camera/+/master/
439 439
440 The source can be located under hal/intel dire 440 The source can be located under hal/intel directory.
441 441
442 Overview of IPU3 pipeline 442 Overview of IPU3 pipeline
443 ========================= 443 =========================
444 444
445 IPU3 pipeline has a number of image processing 445 IPU3 pipeline has a number of image processing stages, each of which takes a
446 set of parameters as input. The major stages o 446 set of parameters as input. The major stages of pipelines are shown here:
447 447
448 .. kernel-render:: DOT 448 .. kernel-render:: DOT
449 :alt: IPU3 ImgU Pipeline 449 :alt: IPU3 ImgU Pipeline
450 :caption: IPU3 ImgU Pipeline Diagram 450 :caption: IPU3 ImgU Pipeline Diagram
451 451
452 digraph "IPU3 ImgU" { 452 digraph "IPU3 ImgU" {
453 node [shape=box] 453 node [shape=box]
454 splines="ortho" 454 splines="ortho"
455 rankdir="LR" 455 rankdir="LR"
456 456
457 a [label="Raw pixels"] 457 a [label="Raw pixels"]
458 b [label="Bayer Downscaling"] 458 b [label="Bayer Downscaling"]
459 c [label="Optical Black Correction"] 459 c [label="Optical Black Correction"]
460 d [label="Linearization"] 460 d [label="Linearization"]
461 e [label="Lens Shading Correction"] 461 e [label="Lens Shading Correction"]
462 f [label="White Balance / Exposure / Fo 462 f [label="White Balance / Exposure / Focus Apply"]
463 g [label="Bayer Noise Reduction"] 463 g [label="Bayer Noise Reduction"]
464 h [label="ANR"] 464 h [label="ANR"]
465 i [label="Demosaicing"] 465 i [label="Demosaicing"]
466 j [label="Color Correction Matrix"] 466 j [label="Color Correction Matrix"]
467 k [label="Gamma correction"] 467 k [label="Gamma correction"]
468 l [label="Color Space Conversion"] 468 l [label="Color Space Conversion"]
469 m [label="Chroma Down Scaling"] 469 m [label="Chroma Down Scaling"]
470 n [label="Chromatic Noise Reduction"] 470 n [label="Chromatic Noise Reduction"]
471 o [label="Total Color Correction"] 471 o [label="Total Color Correction"]
472 p [label="XNR3"] 472 p [label="XNR3"]
473 q [label="TNR"] 473 q [label="TNR"]
474 r [label="DDR", style=filled, fillcolor 474 r [label="DDR", style=filled, fillcolor=yellow, shape=cylinder]
475 s [label="YUV Downscaling"] 475 s [label="YUV Downscaling"]
476 t [label="DDR", style=filled, fillcolor 476 t [label="DDR", style=filled, fillcolor=yellow, shape=cylinder]
477 477
478 { rank=same; a -> b -> c -> d -> e -> f 478 { rank=same; a -> b -> c -> d -> e -> f -> g -> h -> i }
479 { rank=same; j -> k -> l -> m -> n -> o 479 { rank=same; j -> k -> l -> m -> n -> o -> p -> q -> s -> t}
480 480
481 a -> j [style=invis, weight=10] 481 a -> j [style=invis, weight=10]
482 i -> j 482 i -> j
483 q -> r 483 q -> r
484 } 484 }
485 485
486 The table below presents a description of the 486 The table below presents a description of the above algorithms.
487 487
488 ======================== ===================== 488 ======================== =======================================================
489 Name Description 489 Name Description
490 ======================== ===================== 490 ======================== =======================================================
491 Optical Black Correction Optical Black Correct 491 Optical Black Correction Optical Black Correction block subtracts a pre-defined
492 value from the respec 492 value from the respective pixel values to obtain better
493 image quality. 493 image quality.
494 Defined in struct ipu 494 Defined in struct ipu3_uapi_obgrid_param.
495 Linearization This algo block uses 495 Linearization This algo block uses linearization parameters to
496 address non-linearity 496 address non-linearity sensor effects. The Lookup table
497 table is defined in 497 table is defined in
498 struct ipu3_uapi_isp_ 498 struct ipu3_uapi_isp_lin_vmem_params.
499 SHD Lens shading correcti 499 SHD Lens shading correction is used to correct spatial
500 non-uniformity of the 500 non-uniformity of the pixel response due to optical
501 lens shading. This is 501 lens shading. This is done by applying a different gain
502 for each pixel. The g 502 for each pixel. The gain, black level etc are
503 configured in struct 503 configured in struct ipu3_uapi_shd_config_static.
504 BNR Bayer noise reduction 504 BNR Bayer noise reduction block removes image noise by
505 applying a bilateral 505 applying a bilateral filter.
506 See struct ipu3_uapi_ 506 See struct ipu3_uapi_bnr_static_config for details.
507 ANR Advanced Noise Reduct 507 ANR Advanced Noise Reduction is a block based algorithm
508 that performs noise r 508 that performs noise reduction in the Bayer domain. The
509 convolution matrix et 509 convolution matrix etc can be found in
510 struct ipu3_uapi_anr_ 510 struct ipu3_uapi_anr_config.
511 DM Demosaicing converts 511 DM Demosaicing converts raw sensor data in Bayer format
512 into RGB (Red, Green, 512 into RGB (Red, Green, Blue) presentation. Then add
513 outputs of estimation 513 outputs of estimation of Y channel for following stream
514 processing by Firmwar 514 processing by Firmware. The struct is defined as
515 struct ipu3_uapi_dm_c 515 struct ipu3_uapi_dm_config.
516 Color Correction Color Correction algo 516 Color Correction Color Correction algo transforms sensor specific color
517 space to the standard 517 space to the standard "sRGB" color space. This is done
518 by applying 3x3 matri 518 by applying 3x3 matrix defined in
519 struct ipu3_uapi_ccm_ 519 struct ipu3_uapi_ccm_mat_config.
520 Gamma correction Gamma correction stru 520 Gamma correction Gamma correction struct ipu3_uapi_gamma_config is a
521 basic non-linear tone 521 basic non-linear tone mapping correction that is
522 applied per pixel for 522 applied per pixel for each pixel component.
523 CSC Color space conversio 523 CSC Color space conversion transforms each pixel from the
524 RGB primary presentat 524 RGB primary presentation to YUV (Y: brightness,
525 UV: Luminance) presen 525 UV: Luminance) presentation. This is done by applying
526 a 3x3 matrix defined 526 a 3x3 matrix defined in
527 struct ipu3_uapi_csc_ 527 struct ipu3_uapi_csc_mat_config
528 CDS Chroma down sampling 528 CDS Chroma down sampling
529 After the CSC is perf 529 After the CSC is performed, the Chroma Down Sampling
530 is applied for a UV p 530 is applied for a UV plane down sampling by a factor
531 of 2 in each directio 531 of 2 in each direction for YUV 4:2:0 using a 4x2
532 configurable filter s 532 configurable filter struct ipu3_uapi_cds_params.
533 CHNR Chroma noise reductio 533 CHNR Chroma noise reduction
534 This block processes 534 This block processes only the chrominance pixels and
535 performs noise reduct 535 performs noise reduction by cleaning the high
536 frequency noise. 536 frequency noise.
537 See struct struct ipu 537 See struct struct ipu3_uapi_yuvp1_chnr_config.
538 TCC Total color correctio 538 TCC Total color correction as defined in struct
539 struct ipu3_uapi_yuvp 539 struct ipu3_uapi_yuvp2_tcc_static_config.
540 XNR3 eXtreme Noise Reducti 540 XNR3 eXtreme Noise Reduction V3 is the third revision of
541 noise reduction algor 541 noise reduction algorithm used to improve image
542 quality. This removes 542 quality. This removes the low frequency noise in the
543 captured image. Two r 543 captured image. Two related structs are being defined,
544 struct ipu3_uapi_isp_ 544 struct ipu3_uapi_isp_xnr3_params for ISP data memory
545 and struct ipu3_uapi_ 545 and struct ipu3_uapi_isp_xnr3_vmem_params for vector
546 memory. 546 memory.
547 TNR Temporal Noise Reduct 547 TNR Temporal Noise Reduction block compares successive
548 frames in time to rem 548 frames in time to remove anomalies / noise in pixel
549 values. struct ipu3_u 549 values. struct ipu3_uapi_isp_tnr3_vmem_params and
550 struct ipu3_uapi_isp_ 550 struct ipu3_uapi_isp_tnr3_params are defined for ISP
551 vector and data memor 551 vector and data memory respectively.
552 ======================== ===================== 552 ======================== =======================================================
553 553
554 Other often encountered acronyms not listed in 554 Other often encountered acronyms not listed in above table:
555 555
556 ACC 556 ACC
557 Accelerator cluster 557 Accelerator cluster
558 AWB_FR 558 AWB_FR
559 Auto white balance filter resp 559 Auto white balance filter response statistics
560 BDS 560 BDS
561 Bayer downscaler parameters 561 Bayer downscaler parameters
562 CCM 562 CCM
563 Color correction matrix coeffi 563 Color correction matrix coefficients
564 IEFd 564 IEFd
565 Image enhancement filter direc 565 Image enhancement filter directed
566 Obgrid 566 Obgrid
567 Optical black level compensati 567 Optical black level compensation
568 OSYS 568 OSYS
569 Output system configuration 569 Output system configuration
570 ROI 570 ROI
571 Region of interest 571 Region of interest
572 YDS 572 YDS
573 Y down sampling 573 Y down sampling
574 YTM 574 YTM
575 Y-tone mapping 575 Y-tone mapping
576 576
577 A few stages of the pipeline will be executed 577 A few stages of the pipeline will be executed by firmware running on the ISP
578 processor, while many others will use a set of 578 processor, while many others will use a set of fixed hardware blocks also
579 called accelerator cluster (ACC) to crunch pix 579 called accelerator cluster (ACC) to crunch pixel data and produce statistics.
580 580
581 ACC parameters of individual algorithms, as de 581 ACC parameters of individual algorithms, as defined by
582 struct ipu3_uapi_acc_param, can be chosen to b 582 struct ipu3_uapi_acc_param, can be chosen to be applied by the user
583 space through struct struct ipu3_uapi_flags em 583 space through struct struct ipu3_uapi_flags embedded in
584 struct ipu3_uapi_params structure. For paramet 584 struct ipu3_uapi_params structure. For parameters that are configured as
585 not enabled by the user space, the correspondi 585 not enabled by the user space, the corresponding structs are ignored by the
586 driver, in which case the existing configurati 586 driver, in which case the existing configuration of the algorithm will be
587 preserved. 587 preserved.
588 588
589 References 589 References
590 ========== 590 ==========
591 591
592 .. [#f5] drivers/staging/media/ipu3/include/ua 592 .. [#f5] drivers/staging/media/ipu3/include/uapi/intel-ipu3.h
593 593
594 .. [#f1] https://github.com/intel/nvt 594 .. [#f1] https://github.com/intel/nvt
595 595
596 .. [#f2] http://git.ideasonboard.org/yavta.git 596 .. [#f2] http://git.ideasonboard.org/yavta.git
597 597
598 .. [#f3] http://git.ideasonboard.org/?p=media- 598 .. [#f3] http://git.ideasonboard.org/?p=media-ctl.git;a=summary
599 599
600 .. [#f4] ImgU limitation requires an additiona 600 .. [#f4] ImgU limitation requires an additional 16x16 for all input resolutions
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