libcamera: include/libcamera/internal/v4l2_device.h Source File

libcamera v0.0.4 Supporting cameras in Linux since 2019

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v4l2_device.h
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1/* SPDX-License-Identifier: LGPL-2.1-or-later */
2/*
3 * Copyright (C) 2019, Google Inc.
4 *
5 * v4l2_device.h - Common base for V4L2 video devices and subdevices
6 */
7
8#pragma once
9
10#include <map>
11#include <memory>
12#include <optional>
13#include <vector>
14
15#include <linux/videodev2.h>
16
17#include <libcamera/base/log.h>
18#include <libcamera/base/signal.h>
19#include <libcamera/base/span.h>
20#include <libcamera/base/unique_fd.h>
21
22#include <libcamera/color_space.h>
23#include <libcamera/controls.h>
24
25#include "libcamera/internal/formats.h"
26
27namespace libcamera {
28
29class EventNotifier;
30
31 class V4L2Device : protected Loggable
32{
33public:
34 void close();
35 bool isOpen() const { return fd_.isValid(); }
36
37 const ControlInfoMap &controls() const { return controls_; }
38
39 ControlList getControls(const std::vector<uint32_t> &ids);
40 int setControls(ControlList *ctrls);
41
42 const struct v4l2_query_ext_ctrl *controlInfo(uint32_t id) const;
43
44 const std::string &deviceNode() const { return deviceNode_; }
45 std::string devicePath() const;
46
47 int setFrameStartEnabled(bool enable);
48 Signal<uint32_t> frameStart;
49
50 void updateControlInfo();
51
52protected:
53 V4L2Device(const std::string &deviceNode);
54 ~V4L2Device();
55
56 int open(unsigned int flags);
57 int setFd(UniqueFD fd);
58
59 int ioctl(unsigned long request, void *argp);
60
61 int fd() const { return fd_.get(); }
62
63 template<typename T>
64 static std::optional<ColorSpace> toColorSpace(const T &v4l2Format,
65 PixelFormatInfo::ColourEncoding colourEncoding);
66
67 template<typename T>
68 static int fromColorSpace(const std::optional<ColorSpace> &colorSpace, T &v4l2Format);
69
70private:
71 static ControlType v4l2CtrlType(uint32_t ctrlType);
72 static std::unique_ptr<ControlId> v4l2ControlId(const v4l2_query_ext_ctrl &ctrl);
73 std::optional<ControlInfo> v4l2ControlInfo(const v4l2_query_ext_ctrl &ctrl);
74 std::optional<ControlInfo> v4l2MenuControlInfo(const v4l2_query_ext_ctrl &ctrl);
75
76 void listControls();
77 void updateControls(ControlList *ctrls,
78 Span<const v4l2_ext_control> v4l2Ctrls);
79
80 void eventAvailable();
81
82 std::map<unsigned int, struct v4l2_query_ext_ctrl> controlInfo_;
83 std::vector<std::unique_ptr<ControlId>> controlIds_;
84 ControlIdMap controlIdMap_;
85 ControlInfoMap controls_;
86 std::string deviceNode_;
87 UniqueFD fd_;
88
89 EventNotifier *fdEventNotifier_;
90 bool frameStartEnabled_;
91};
92
93} /* namespace libcamera */
libcamera::ControlInfoMap
A map of ControlId to ControlInfo.
Definition: controls.h:306
libcamera::ControlList
Associate a list of ControlId with their values for an object.
Definition: controls.h:350
libcamera::EventNotifier
Notify of activity on a file descriptor.
Definition: event_notifier.h:20
libcamera::Loggable
Base class to support log message extensions.
Definition: log.h:91
libcamera::PixelFormatInfo::ColourEncoding
ColourEncoding
The colour encoding type.
Definition: formats.h:24
libcamera::Signal
Generic signal and slot communication mechanism.
Definition: signal.h:39
libcamera::UniqueFD
unique_ptr-like wrapper for a file descriptor
Definition: unique_fd.h:18
libcamera::UniqueFD::get
int get() const
Retrieve the managed file descriptor.
Definition: unique_fd.h:60
libcamera::UniqueFD::isValid
bool isValid() const
Check if the UniqueFD owns a valid file descriptor.
Definition: unique_fd.h:61
libcamera::V4L2Device
Base class for V4L2VideoDevice and V4L2Subdevice.
Definition: v4l2_device.h:32
libcamera::V4L2Device::~V4L2Device
~V4L2Device()
Destroy a V4L2Device.
Definition: v4l2_device.cpp:69
libcamera::V4L2Device::isOpen
bool isOpen() const
Check if the V4L2 device node is open.
Definition: v4l2_device.h:35
libcamera::V4L2Device::setFrameStartEnabled
int setFrameStartEnabled(bool enable)
Enable or disable frame start event notification.
Definition: v4l2_device.cpp:423
libcamera::V4L2Device::ioctl
int ioctl(unsigned long request, void *argp)
Perform an IOCTL system call on the device node.
Definition: v4l2_device.cpp:454
libcamera::V4L2Device::fromColorSpace
static int fromColorSpace(const std::optional< ColorSpace > &colorSpace, T &v4l2Format)
Fill in the color space fields of a V4L2 format from a ColorSpace.
Definition: v4l2_device.cpp:926
libcamera::V4L2Device::controls
const ControlInfoMap & controls() const
Retrieve the supported V4L2 controls and their information.
Definition: v4l2_device.h:37
libcamera::V4L2Device::close
void close()
Close the device node.
Definition: v4l2_device.cpp:140
libcamera::V4L2Device::updateControlInfo
void updateControlInfo()
Update the information for all device controls.
Definition: v4l2_device.cpp:673
libcamera::V4L2Device::frameStart
Signal< uint32_t > frameStart
A Signal emitted when capture of a frame has started.
Definition: v4l2_device.h:48
libcamera::V4L2Device::open
int open(unsigned int flags)
Open a V4L2 device node.
Definition: v4l2_device.cpp:82
libcamera::V4L2Device::fd
int fd() const
Retrieve the V4L2 device file descriptor.
Definition: v4l2_device.h:61
libcamera::V4L2Device::devicePath
std::string devicePath() const
Retrieve the device path in sysfs.
Definition: v4l2_device.cpp:397
libcamera::V4L2Device::getControls
ControlList getControls(const std::vector< uint32_t > &ids)
Read controls from the device.
Definition: v4l2_device.cpp:177
libcamera::V4L2Device::setControls
int setControls(ControlList *ctrls)
Write controls to the device.
Definition: v4l2_device.cpp:281
libcamera::V4L2Device::setFd
int setFd(UniqueFD fd)
Set the file descriptor of a V4L2 device.
Definition: v4l2_device.cpp:119
libcamera::V4L2Device::toColorSpace
static std::optional< ColorSpace > toColorSpace(const T &v4l2Format, PixelFormatInfo::ColourEncoding colourEncoding)
Convert the color space fields in a V4L2 format to a ColorSpace.
Definition: v4l2_device.cpp:847
libcamera::V4L2Device::controlInfo
const struct v4l2_query_ext_ctrl * controlInfo(uint32_t id) const
Retrieve the v4l2_query_ext_ctrl information for the given control.
Definition: v4l2_device.cpp:377
libcamera::V4L2Device::deviceNode
const std::string & deviceNode() const
Retrieve the device node path.
Definition: v4l2_device.h:44
color_space.h
Class and enums to represent color spaces.
controls.h
Framework to manage controls related to an object.
formats.h
Types and helper functions to handle libcamera image formats.
log.h
Logging infrastructure.
libcamera
Top-level libcamera namespace.
Definition: backtrace.h:17
libcamera::ControlType
ControlType
Define the data type of a Control.
Definition: controls.h:27
libcamera::ControlIdMap
std::unordered_map< unsigned int, const ControlId * > ControlIdMap
A map of numerical control ID to ControlId.
Definition: controls.h:303
signal.h
Signal & slot implementation.
unique_fd.h
File descriptor wrapper that owns a file descriptor.