libcamera/vivid.git - libcamera pipeline handler for VIVID

diff options

author	Umang Jain <umang.jain@ideasonboard.com>	2021-05-27 12:28:29 +0530
committer	Paul Elder <paul.elder@ideasonboard.com>	2021-06-04 18:34:47 +0900
commit	388c4392c1527c7f7b485480496a1d4399c2ea9e (patch)
tree	2167467dac632f08740d9e98fb5f571b8695d758 /test/log/log_api.cpp
parent	59de56f42a0fda1b8e778fb237b7bce494dc0584 (diff)

libcamera: Add IMX258 sensor properties

Brief specifications available at https://www.sony-semicon.co.jp/products/common/pdf/ProductBrief_IMX258_20151015.pdf Signed-off-by: Umang Jain <umang.jain@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com> Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>

Diffstat (limited to 'test/log/log_api.cpp')

0 files changed, 0 insertions, 0 deletions

id='n125' href='#n125'>125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400

.. SPDX-License-Identifier: CC-BY-SA-4.0

.. contents::
   :local:

*************
Documentation
*************

.. toctree::
   :hidden:

   API <api-html/index>

API
===

The libcamera API is extensively documented using Doxygen. The :ref:`API
nightly build <api>` contains the most up-to-date API documentation, built from
the latest master branch.

Feature Requirements
====================

Device enumeration
------------------

The library shall support enumerating all camera devices available in the
system, including both fixed cameras and hotpluggable cameras. It shall
support cameras plugged and unplugged after the initialization of the
library, and shall offer a mechanism to notify applications of camera plug
and unplug.

The following types of cameras shall be supported:

* Internal cameras designed for point-and-shoot still image and video
  capture usage, either controlled directly by the CPU, or exposed through
  an internal USB bus as a UVC device.

* External UVC cameras designed for video conferencing usage.

Other types of camera, including analog cameras, depth cameras, thermal
cameras, external digital picture or movie cameras, are out of scope for
this project.

A hardware device that includes independent camera sensors, such as front
and back sensors in a phone, shall be considered as multiple camera devices
for the purpose of this library.

Independent Camera Devices
--------------------------

When multiple cameras are present in the system and are able to operate
independently from each other, the library shall expose them as multiple
camera devices and support parallel operation without any additional usage
restriction apart from the limitations inherent to the hardware (such as
memory bandwidth, CPU usage or number of CSI-2 receivers for instance).

Independent processes shall be able to use independent cameras devices
without interfering with each other. A single camera device shall be
usable by a single process at a time.

Multiple streams support
------------------------

The library shall support multiple video streams running in parallel
for each camera device, within the limits imposed by the system.

Per frame controls
------------------

The library shall support controlling capture parameters for each stream
on a per-frame basis, on a best effort basis based on the capabilities of the
hardware and underlying software stack (including kernel drivers and
firmware). It shall apply capture parameters to the frame they target, and
report the value of the parameters that have effectively been used for each
captured frame.

When a camera device supports multiple streams, the library shall allow both
control of each stream independently, and control of multiple streams
together. Streams that are controlled together shall be synchronized. No
synchronization is required for streams controlled independently.

Capability Enumeration
----------------------

The library shall expose capabilities of each camera device in a way that
allows applications to discover those capabilities dynamically. Applications
shall be allowed to cache capabilities for as long as they are using the
library. If capabilities can change at runtime, the library shall offer a
mechanism to notify applications of such changes. Applications shall not
cache capabilities in long term storage between runs.

Capabilities shall be discovered dynamically at runtime from the device when
possible, and may come, in part or in full, from platform configuration
data.

Device Profiles
---------------

The library may define different camera device profiles, each with a minimum
set of required capabilities. Applications may use those profiles to quickly
determine the level of features exposed by a device without parsing the full
list of capabilities. Camera devices may implement additional capabilities
on top of the minimum required set for the profile they expose.

3A and Image Enhancement Algorithms
-----------------------------------

The camera devices shall implement auto exposure, auto gain and auto white
balance. Camera devices that include a focus lens shall implement auto
focus. Additional image enhancement algorithms, such as noise reduction or
video stabilization, may be implemented.

All algorithms may be implemented in hardware or firmware outside of the
library, or in software in the library. They shall all be controllable by
applications.

The library shall be architectured to isolate the 3A and image enhancement
algorithms in a component with a documented API, respectively called the 3A
component and the 3A API. The 3A API shall be stable, and shall allow both
open-source and closed-source implementations of the 3A component.

The library may include statically-linked open-source 3A components, and
shall support dynamically-linked open-source and closed-source 3A
components.

Closed-source 3A Component Sandboxing
-------------------------------------

For security purposes, it may be desired to run closed-source 3A components
in a separate process. The 3A API would in such a case be transported over
IPC. The 3A API shall make it possible to use any IPC mechanism that
supports passing file descriptors.

The library may implement an IPC mechanism, and shall support third-party
platform-specific IPC mechanisms through the implementation of a
platform-specific 3A API wrapper. No modification to the library shall be
needed to use such third-party IPC mechanisms.

The 3A component shall not directly access any device node on the system.
Such accesses shall instead be performed through the 3A API. The library
shall validate all accesses and restrict them to what is absolutely required
by 3A components.

V4L2 Compatibility Layer
------------------------

The project shall support traditional V4L2 application through an additional
libcamera wrapper library. The wrapper library shall trap all accesses to
camera devices through `LD_PRELOAD`, and route them through libcamera to
emulate a high-level V4L2 camera device. It shall expose camera device
features on a best-effort basis, and aim for the level of features
traditionally available from a UVC camera designed for video conferencing.

Android Camera HAL v3 Compatibility
-----------------------------------

The library API shall expose all the features required to implement an
Android Camera HAL v3 on top of libcamera. Some features of the HAL may be
omitted as long as they can be implemented separately in the HAL, such as
JPEG encoding, or YUV reprocessing.


Camera Stack
============

::

    a c /    +-------------+  +-------------+  +-------------+  +-------------+
    p a |    |   Native    |  |  Framework  |  |   Native    |  |   Android   |
    p t |    |    V4L2     |  | Application |  |  libcamera  |  |   Camera    |
    l i |    | Application |  | (gstreamer) |  | Application |  |  Framework  |
    i o \    +-------------+  +-------------+  +-------------+  +-------------+
      n             ^                ^                ^                ^
                    |                |                |                |
    l a             |                |                |                |
    i d             v                v                |                v
    b a /    +-------------+  +-------------+         |         +-------------+
    c p |    |    V4L2     |  |   Camera    |         |         |   Android   |
    a t |    |   Compat.   |  |  Framework  |         |         |   Camera    |
    m a |    |             |  | (gstreamer) |         |         |     HAL     |
    e t \    +-------------+  +-------------+         |         +-------------+
    r i             ^                ^                |                ^
    a o             |                |                |                |
      n             |                |                |                |
        /           |         ,................................................
        |           |         !      :            Language             :      !
    l f |           |         !      :            Bindings             :      !
    i r |           |         !      :           (optional)            :      !
    b a |           |         \...............................................'
    c m |           |                |                |                |
    a e |           |                |                |                |
    m w |           v                v                v                v
    e o |    +----------------------------------------------------------------+
    r r |    |                                                                |
    a k |    |                           libcamera                            |
        |    |                                                                |
        \    +----------------------------------------------------------------+
                            ^                  ^                  ^
    Userspace               |                  |                  |
   ------------------------ | ---------------- | ---------------- | ---------------
    Kernel                  |                  |                  |
                            v                  v                  v
                      +-----------+      +-----------+      +-----------+
                      |   Media   | <--> |   Video   | <--> |   V4L2    |
                      |  Device   |      |  Device   |      |  Subdev   |
                      +-----------+      +-----------+      +-----------+

The camera stack comprises four software layers. From bottom to top:

* The kernel drivers control the camera hardware and expose a
  low-level interface to userspace through the Linux kernel V4L2
  family of APIs (Media Controller API, V4L2 Video Device API and
  V4L2 Subdev API).

* The libcamera framework is the core part of the stack. It
  handles all control of the camera devices in its core component,
  libcamera, and exposes a native C++ API to upper layers. Optional
  language bindings allow interfacing to libcamera from other
  programming languages.

  Those components live in the same source code repository and
  all together constitute the libcamera framework.

* The libcamera adaptation is an umbrella term designating the
  components that interface to libcamera in other frameworks.
  Notable examples are a V4L2 compatibility layer, a gstreamer
  libcamera element, and an Android camera HAL implementation based
  on libcamera.

  Those components can live in the libcamera project source code
  in separate repositories, or move to their respective project's
  repository (for instance the gstreamer libcamera element).

* The applications and upper level frameworks are based on the
  libcamera framework or libcamera adaptation, and are outside of
  the scope of the libcamera project.


libcamera Architecture
======================

::

   ---------------------------< libcamera Public API >---------------------------
                    ^                                      ^
                    |                                      |
                    v                                      v
             +-------------+  +-------------------------------------------------+
             |   Camera    |  |  Camera Device                                  |
             |   Devices   |  | +---------------------------------------------+ |
             |   Manager   |  | | Device-Agnostic                             | |
             +-------------+  | |                                             | |
                    ^         | |                    +------------------------+ |
                    |         | |                    |   ~~~~~~~~~~~~~~~~~~~~~  |
                    |         | |                    |  {  +---------------+  } |
                    |         | |                    |  }  | ////Image//// |  { |
                    |         | |                    | <-> | /Processing// |  } |
                    |         | |                    |  }  | /Algorithms// |  { |
                    |         | |                    |  {  +---------------+  } |
                    |         | |                    |   ~~~~~~~~~~~~~~~~~~~~~  |
                    |         | |                    | ======================== |
                    |         | |                    |     +---------------+    |
                    |         | |                    |     | //Pipeline/// |    |
                    |         | |                    | <-> | ///Handler/// |    |
                    |         | |                    |     | ///////////// |    |
                    |         | +--------------------+     +---------------+    |
                    |         |                                 Device-Specific |
                    |         +-------------------------------------------------+
                    |                     ^                        ^
                    |                     |                        |
                    v                     v                        v
           +--------------------------------------------------------------------+
           | Helpers and Support Classes                                        |


context:
space:
mode: