libcamera  v0.3.2+116-83c5ad0f
Supporting cameras in Linux since 2019
Namespaces | Classes | Typedefs | Enumerations | Functions
libcamera Namespace Reference

Top-level libcamera namespace. More...

Namespaces

 controls
 Namespace for libcamera controls.
 
 properties
 Namespace for libcamera properties.
 

Classes

class  Camera
 Camera device. More...
 
class  CameraConfiguration
 Hold configuration for streams of the camera. More...
 
class  CameraManager
 Provide access and manage all cameras in the system. More...
 
class  ColorSpace
 Class to describe a color space. More...
 
class  Control
 Describe a control and its intrinsic properties. More...
 
class  ControlId
 Control static metadata. More...
 
class  ControlInfo
 Describe the limits of valid values for a Control. More...
 
class  ControlInfoMap
 A map of ControlId to ControlInfo. More...
 
class  ControlList
 Associate a list of ControlId with their values for an object. More...
 
class  ControlValue
 Abstract type representing the value of a control. More...
 
class  Fence
 Synchronization primitive to manage resources. More...
 
class  Flags
 Type-safe container for enum-based bitfields. More...
 
class  FrameBuffer
 Frame buffer data and its associated dynamic metadata. More...
 
class  FrameBufferAllocator
 FrameBuffer allocator for applications. More...
 
struct  FrameMetadata
 Metadata related to a captured frame. More...
 
class  PixelFormat
 libcamera image pixel format More...
 
class  Point
 Describe a point in two-dimensional space. More...
 
class  Rectangle
 Describe a rectangle's position and dimensions. More...
 
class  Request
 A frame capture request. More...
 
class  SensorConfiguration
 Camera sensor configuration. More...
 
class  SharedFD
 RAII-style wrapper for file descriptors. More...
 
class  Signal
 Generic signal and slot communication mechanism. More...
 
class  Size
 Describe a two-dimensional size. More...
 
class  SizeRange
 Describe a range of sizes. More...
 
class  Stream
 Video stream for a camera. More...
 
struct  StreamConfiguration
 Configuration parameters for a stream. More...
 
class  StreamFormats
 Hold information about supported stream formats. More...
 
class  UniqueFD
 unique_ptr-like wrapper for a file descriptor More...
 

Typedefs

using ControlIdMap = std::unordered_map< unsigned int, const ControlId * >
 A map of numerical control ID to ControlId. More...
 

Enumerations

enum  ConnectionType { ConnectionTypeAuto, ConnectionTypeDirect, ConnectionTypeQueued, ConnectionTypeBlocking }
 Connection type for asynchronous communication. More...
 
enum  ControlType {
  ControlTypeNone, ControlTypeBool, ControlTypeByte, ControlTypeInteger32,
  ControlTypeInteger64, ControlTypeFloat, ControlTypeString
}
 Define the data type of a Control. More...
 
enum  Orientation {
  Orientation::Rotate0 = 1, Orientation::Rotate0Mirror, Orientation::Rotate180, Orientation::Rotate180Mirror,
  Orientation::Rotate90Mirror, Orientation::Rotate270, Orientation::Rotate270Mirror, Orientation::Rotate90
}
 The image orientation in a memory buffer. More...
 
enum  StreamRole { StreamRole::Raw, StreamRole::StillCapture, StreamRole::VideoRecording, StreamRole::Viewfinder }
 Identify the role a stream is intended to play. More...
 
enum  Transform : int {
  Transform::Identity = 0, Transform::Rot0 = Identity, Transform::HFlip = 1, Transform::VFlip = 2,
  Transform::HVFlip = HFlip | VFlip, Transform::Rot180 = HVFlip, Transform::Transpose = 4, Transform::Rot270 = HFlip | Transpose,
  Transform::Rot90 = VFlip | Transpose, Transform::Rot180Transpose = HFlip | VFlip | Transpose
}
 Enum to represent a 2D plane transform. More...
 

Functions

bool operator== (const ColorSpace &lhs, const ColorSpace &rhs)
 Compare color spaces for equality. More...
 
bool operator== (const Point &lhs, const Point &rhs)
 Compare points for equality. More...
 
std::ostream & operator<< (std::ostream &out, const Point &p)
 Insert a text representation of a Point into an output stream. More...
 
bool operator== (const Size &lhs, const Size &rhs)
 Compare sizes for equality. More...
 
bool operator< (const Size &lhs, const Size &rhs)
 Compare sizes for smaller than order. More...
 
std::ostream & operator<< (std::ostream &out, const Size &s)
 Insert a text representation of a Size into an output stream. More...
 
bool operator== (const SizeRange &lhs, const SizeRange &rhs)
 Compare size ranges for equality. More...
 
std::ostream & operator<< (std::ostream &out, const SizeRange &sr)
 Insert a text representation of a SizeRange into an output stream. More...
 
bool operator== (const Rectangle &lhs, const Rectangle &rhs)
 Compare rectangles for equality. More...
 
std::ostream & operator<< (std::ostream &out, const Rectangle &r)
 Insert a text representation of a Rectangle into an output stream. More...
 
Orientation orientationFromRotation (int angle, bool *success)
 Return the orientation representing a rotation of the given angle clockwise. More...
 
std::ostream & operator<< (std::ostream &out, const Orientation &orientation)
 Prints human-friendly names for Orientation items. More...
 
std::ostream & operator<< (std::ostream &out, const PixelFormat &f)
 Insert a text representation of a PixelFormat into an output stream. More...
 
std::ostream & operator<< (std::ostream &out, const Request &r)
 Insert a text representation of a Request into an output stream. More...
 
std::ostream & operator<< (std::ostream &out, StreamRole role)
 Insert a text representation of a StreamRole into an output stream. More...
 
constexpr Transform operator & (Transform t0, Transform t1)
 Apply bitwise AND operator between the bits in the two transforms. More...
 
constexpr Transform operator| (Transform t0, Transform t1)
 Apply bitwise OR operator between the bits in the two transforms. More...
 
constexpr Transform operator^ (Transform t0, Transform t1)
 Apply bitwise XOR operator between the bits in the two transforms. More...
 
constexpr Transformoperator &= (Transform &t0, Transform t1)
 Apply bitwise AND-assignment operator between the bits in the two transforms. More...
 
constexpr Transformoperator|= (Transform &t0, Transform t1)
 Apply bitwise OR-assignment operator between the bits in the two transforms. More...
 
constexpr Transformoperator^= (Transform &t0, Transform t1)
 Apply bitwise XOR-assignment operator between the bits in the two transforms. More...
 
Transform operator* (Transform t0, Transform t1)
 Compose two transforms by applying t0 first then t1. More...
 
Transform operator- (Transform t)
 Invert a transform. More...
 
constexpr bool operator! (Transform t)
 Return true if the transform is the Identity, otherwise false More...
 
constexpr Transform operator~ (Transform t)
 Return the transform with all the bits inverted individually. More...
 
Transform transformFromRotation (int angle, bool *success)
 Return the transform representing a rotation of the given angle clockwise. More...
 
Transform operator/ (const Orientation &o1, const Orientation &o2)
 Return the Transform that applied to o2 gives o1. More...
 
Orientation operator* (const Orientation &o, const Transform &t)
 Apply the Transform t on the orientation o. More...
 
const char * transformToString (Transform t)
 Return a character string describing the transform. More...
 

Detailed Description

Top-level libcamera namespace.

Typedef Documentation

◆ ControlIdMap

A map of numerical control ID to ControlId.

The map is used by ControlList instances to access controls by numerical IDs. A global map of all libcamera controls is provided by controls::controls.

Enumeration Type Documentation

◆ ConnectionType

Connection type for asynchronous communication.

This enumeration describes the possible types of asynchronous communication between a sender and a receiver. It applies to Signal::emit() and Object::invokeMethod().

Enumerator
ConnectionTypeAuto 

If the sender and the receiver live in the same thread, ConnectionTypeDirect is used. Otherwise ConnectionTypeQueued is used.

ConnectionTypeDirect 

The receiver is invoked immediately and synchronously in the sender's thread.

ConnectionTypeQueued 

The receiver is invoked asynchronously.

Invoke the receiver asynchronously in its thread when control returns to the thread's event loop. The sender proceeds without waiting for the invocation to complete.

ConnectionTypeBlocking 

The receiver is invoked synchronously.

If the sender and the receiver live in the same thread, this is equivalent to ConnectionTypeDirect. Otherwise, the receiver is invoked asynchronously in its thread when control returns to the thread's event loop. The sender blocks until the receiver signals the completion of the invocation.

◆ ControlType

Define the data type of a Control.

Enumerator
ControlTypeNone 

Invalid type, for empty values

ControlTypeBool 

The control stores a boolean value

ControlTypeByte 

The control stores a byte value as an unsigned 8-bit integer

ControlTypeInteger32 

The control stores a 32-bit integer value

ControlTypeInteger64 

The control stores a 64-bit integer value

ControlTypeFloat 

The control stores a 32-bit floating point value

ControlTypeString 

The control stores a string value as an array of char

◆ Orientation

The image orientation in a memory buffer.

The Orientation enumeration describes the orientation of the images produced by the camera pipeline as they get received by the application inside memory buffers.

The image orientation expressed using the Orientation enumeration can be then inferred by applying to a naturally oriented image a multiple of a 90 degrees rotation in the clockwise direction from the origin and then by applying an optional horizontal mirroring.

The enumeration numerical values follow the ones defined by the EXIF Specification version 2.32, Tag 274 "Orientation", while the names of the enumerated values report the rotation and mirroring operations performed.

For example, Orientation::Rotate90Mirror describes the orientation obtained by rotating the image 90 degrees clockwise first and then applying a horizontal mirroring.

Enumerator
Rotate0 
rotate0.svg
Rotate0Mirror 
rotate0Mirror.svg
Rotate180 
rotate180.svg
Rotate180Mirror 
rotate180Mirror.svg
Rotate90Mirror 
rotate90Mirror.svg
Rotate270 
rotate270.svg
Rotate270Mirror 
rotate270Mirror.svg
Rotate90 
rotate90.svg

◆ StreamRole

enum libcamera::StreamRole
strong

Identify the role a stream is intended to play.

The StreamRole describes how an application intends to use a stream. Roles are specified by applications and passed to cameras, that then select the most appropriate streams and their default configurations.

Enumerator
Raw 

The stream is intended to capture raw frames from the sensor.

StillCapture 

The stream is intended to capture high-resolution, high-quality still images with low frame rate. The captured frames may be exposed with flash.

VideoRecording 

The stream is intended to capture video for the purpose of recording or streaming. The video stream may produce a high frame rate and may be enhanced with video stabilization.

Viewfinder 

The stream is intended to capture video for the purpose of display on the local screen. Trade-offs between quality and usage of system resources are acceptable.

◆ Transform

enum libcamera::Transform : int
strong

Enum to represent a 2D plane transform.

The Transform can take 8 distinct values, representing the usual 2D plane transforms listed below. Each of these transforms can be constructed out of 3 basic operations, namely a horizontal flip (mirror), a vertical flip, and a transposition (about the main diagonal). The transforms are encoded such that a single bit indicates the presence of each of the 3 basic operations:

  • bit 0 - presence of a horizontal flip
  • bit 1 - presence of a vertical flip
  • bit 2 - presence of a transposition.

We regard these 3 basic operations as being applied in a specific order: first the two flip operations (actually they commute, so the order between them is unimportant) and finally any transpose operation.

Functions are provided to manipulate directly the bits within the transform encoding, but there are also higher-level functions to invert and compose transforms. Transforms are composed according to the usual mathematical convention such that the right transform is applied first, and the left transform is applied second.

Finally, we have a total of 8 distinct transformations, as follows (a couple of them have additional synonyms for convenience). We illustrate each with its nominal effect on a rectangle with vertices labelled A, B, C and D.

See also
https://en.wikipedia.org/wiki/Examples_of_groups#dihedral_group_of_order_8

The set of 2D plane transforms is also known as the symmetry group of a square, described in the link. Note that the group can be generated by only 2 elements (the horizontal flip and a 90 degree rotation, for example), however, the encoding used here makes the presence of the vertical flip explicit.

Enumerator
Identity 

Identity transform.

A-B A-B
Input image | | goes to output image | |
C-D C-D

Numeric value: 0 (no bits set).

Rot0 

Synonym for Transform::Identity (zero degree rotation).

HFlip 

Horizontal flip.

A-B B-A
Input image | | goes to output image | |
C-D D-C

Numeric value: 1 (horizontal flip bit set only).

VFlip 

Vertical flip.

A-B C-D
Input image | | goes to output image | |
C-D A-B

Numeric value: 2 (vertical flip bit set only).

HVFlip 

Horizontal and vertical flip (identical to a 180 degree rotation).

A-B D-C
Input image | | goes to output image | |
C-D B-A

Numeric value: 3 (horizontal and vertical flip bits set).

Rot180 

Synonym for HVFlip (180 degree rotation).

Transpose 

Transpose (about the main diagonal).

A-B A-C
Input image | | goes to output image | |
C-D B-D

Numeric value: 4 (transpose bit set only).

Rot270 

Rotation by 270 degrees clockwise (90 degrees anticlockwise).

A-B B-D
Input image | | goes to output image | |
C-D A-C

Numeric value: 5 (transpose and horizontal flip bits set).

Rot90 

Rotation by 90 degrees clockwise (270 degrees anticlockwise).

A-B C-A
Input image | | goes to output image | |
C-D D-B

Numeric value: 6 (transpose and vertical flip bits set).

Rot180Transpose 

Rotation by 180 degrees followed by transpose (alternatively, transposition about the "opposite diagonal").

A-B D-B
Input image | | goes to output image | |
C-D C-A

Numeric value: 7 (all bits set).

Function Documentation

◆ operator &()

libcamera::operator& ( Transform  t0,
Transform  t1 
)

Apply bitwise AND operator between the bits in the two transforms.

Parameters
[in]t0The first transform
[in]t1The second transform

◆ operator &=()

libcamera::operator&= ( Transform t0,
Transform  t1 
)

Apply bitwise AND-assignment operator between the bits in the two transforms.

Parameters
[in]t0The first transform
[in]t1The second transform

◆ operator!()

libcamera::operator! ( Transform  t)

Return true if the transform is the Identity, otherwise false

Parameters
[in]tThe transform to be tested

◆ operator*() [1/2]

Transform libcamera::operator* ( Transform  t0,
Transform  t1 
)

Compose two transforms by applying t0 first then t1.

Parameters
[in]t0The first transform to apply
[in]t1The second transform to apply

Compose two transforms into a transform that is equivalent to first applying t0 and then applying t1. For example, HFlip * Transpose performs HFlip first and then the Transpose yielding Rot270, as shown below.

A-B B-A B-D
Input image | | -> HFLip -> | | -> Transpose -> | | = Rot270
C-D D-C A-C

Note that composition is generally non-commutative for Transforms, and not the same as XOR-ing the underlying bit representations.

Returns
A Transform equivalent to applying t0 and then t1

◆ operator*() [2/2]

Orientation libcamera::operator* ( const Orientation o,
const Transform t 
)

Apply the Transform t on the orientation o.

Parameters
oThe orientation
tThe transform to apply on o
Returns
The Orientation resulting from applying t on o

◆ operator-()

Transform libcamera::operator- ( Transform  t)

Invert a transform.

Parameters
[in]tThe transform to be inverted

That is, we return the transform such that t * (-t) and (-t) * t both yield the identity transform.

◆ operator/()

Transform libcamera::operator/ ( const Orientation o1,
const Orientation o2 
)

Return the Transform that applied to o2 gives o1.

Parameters
o1The Orientation to obtain
o2The base Orientation

This operation can be used to easily compute the Transform to apply to a base orientation o2 to get the desired orientation o1.

Returns
A Transform that applied to o2 gives o1

◆ operator<()

bool libcamera::operator< ( const Size lhs,
const Size rhs 
)

Compare sizes for smaller than order.

Sizes are compared on three criteria, in the following order.

  • A size with smaller width and smaller height is smaller.
  • A size with smaller area is smaller.
  • A size with smaller width is smaller.
Returns
True if lhs is smaller than rhs, false otherwise

◆ operator<<() [1/8]

std::ostream & libcamera::operator<< ( std::ostream &  out,
const Orientation orientation 
)

Prints human-friendly names for Orientation items.

Parameters
[in]outThe output stream
[in]orientationThe Orientation item
Returns
The output stream out

◆ operator<<() [2/8]

std::ostream & libcamera::operator<< ( std::ostream &  out,
const PixelFormat f 
)

Insert a text representation of a PixelFormat into an output stream.

Parameters
[in]outThe output stream
[in]fThe PixelFormat
Returns
The output stream out

◆ operator<<() [3/8]

std::ostream & libcamera::operator<< ( std::ostream &  out,
const Point p 
)

Insert a text representation of a Point into an output stream.

Parameters
[in]outThe output stream
[in]pThe point
Returns
The output stream out

◆ operator<<() [4/8]

std::ostream & libcamera::operator<< ( std::ostream &  out,
StreamRole  role 
)

Insert a text representation of a StreamRole into an output stream.

Parameters
[in]outThe output stream
[in]roleThe StreamRole
Returns
The output stream out

◆ operator<<() [5/8]

std::ostream & libcamera::operator<< ( std::ostream &  out,
const Request r 
)

Insert a text representation of a Request into an output stream.

Parameters
[in]outThe output stream
[in]rThe Request
Returns
The output stream out

◆ operator<<() [6/8]

std::ostream & libcamera::operator<< ( std::ostream &  out,
const Size s 
)

Insert a text representation of a Size into an output stream.

Parameters
[in]outThe output stream
[in]sThe size
Returns
The output stream out

◆ operator<<() [7/8]

std::ostream & libcamera::operator<< ( std::ostream &  out,
const SizeRange sr 
)

Insert a text representation of a SizeRange into an output stream.

Parameters
[in]outThe output stream
[in]srThe size range
Returns
The output stream out

◆ operator<<() [8/8]

std::ostream & libcamera::operator<< ( std::ostream &  out,
const Rectangle r 
)

Insert a text representation of a Rectangle into an output stream.

Parameters
[in]outThe output stream
[in]rThe rectangle
Returns
The output stream out

◆ operator==() [1/5]

bool libcamera::operator== ( const Point lhs,
const Point rhs 
)

Compare points for equality.

Returns
True if the two points are equal, false otherwise

◆ operator==() [2/5]

bool libcamera::operator== ( const ColorSpace lhs,
const ColorSpace rhs 
)

Compare color spaces for equality.

Returns
True if the two color spaces are identical, false otherwise

◆ operator==() [3/5]

bool libcamera::operator== ( const Size lhs,
const Size rhs 
)

Compare sizes for equality.

Returns
True if the two sizes are equal, false otherwise

◆ operator==() [4/5]

bool libcamera::operator== ( const SizeRange lhs,
const SizeRange rhs 
)

Compare size ranges for equality.

Returns
True if the two size ranges are equal, false otherwise

◆ operator==() [5/5]

bool libcamera::operator== ( const Rectangle lhs,
const Rectangle rhs 
)

Compare rectangles for equality.

Returns
True if the two rectangles are equal, false otherwise

◆ operator^()

libcamera::operator^ ( Transform  t0,
Transform  t1 
)

Apply bitwise XOR operator between the bits in the two transforms.

Parameters
[in]t0The first transform
[in]t1The second transform

◆ operator^=()

libcamera::operator^= ( Transform t0,
Transform  t1 
)

Apply bitwise XOR-assignment operator between the bits in the two transforms.

Parameters
[in]t0The first transform
[in]t1The second transform

◆ operator|()

libcamera::operator| ( Transform  t0,
Transform  t1 
)

Apply bitwise OR operator between the bits in the two transforms.

Parameters
[in]t0The first transform
[in]t1The second transform

◆ operator|=()

libcamera::operator|= ( Transform t0,
Transform  t1 
)

Apply bitwise OR-assignment operator between the bits in the two transforms.

Parameters
[in]t0The first transform
[in]t1The second transform

◆ operator~()

libcamera::operator~ ( Transform  t)

Return the transform with all the bits inverted individually.

Parameters
[in]tThe transform of which the bits will be inverted

This inverts the bits that encode the transform in a bitwise manner. Note that this is not the proper inverse of transform t (for which use operator-).

◆ orientationFromRotation()

Orientation libcamera::orientationFromRotation ( int  angle,
bool *  success 
)

Return the orientation representing a rotation of the given angle clockwise.

Parameters
[in]angleThe angle of rotation in a clockwise sense. Negative values can be used to represent anticlockwise rotations
[out]successSet to true if the angle is a multiple of 90 degrees, otherwise false
Returns
The orientation corresponding to the rotation if success was set to true, otherwise the Rotate0 orientation

◆ transformFromRotation()

Transform libcamera::transformFromRotation ( int  angle,
bool *  success 
)

Return the transform representing a rotation of the given angle clockwise.

Parameters
[in]angleThe angle of rotation in a clockwise sense. Negative values can be used to represent anticlockwise rotations
[out]successSet to true if the angle is a multiple of 90 degrees, otherwise false
Returns
The transform corresponding to the rotation if success was set to true, otherwise the Identity transform

◆ transformToString()

const char * libcamera::transformToString ( Transform  t)

Return a character string describing the transform.

Parameters
[in]tThe transform to be described.