Here is a list of all documented files with brief descriptions:

build
include
libcamera
ipa
core_ipa_interface.h	Libcamera structs for IPAs
control_ids.h	Camera controls identifiers
formats.h
libcamera.h
property_ids.h	Camera properties identifiers
version.h
src
libcamera
shaders
glsl_shaders.h
include
libcamera
base
backtrace.h	Generate call stack backtraces
bound_method.h	Method bind and invocation
class.h	Utilities to help constructing class interfaces
event_dispatcher.h
event_dispatcher_poll.h
event_notifier.h	File descriptor event notifier
file.h	File I/O operations
flags.h	Enum-based bit fields
log.h	Logging infrastructure
memfd.h	Anonymous file creation
message.h	Message queue support
mutex.h	Mutex classes with clang thread safety annotation
object.h	Base object to support automatic signal disconnection
private.h
regex.h
semaphore.h	General-purpose counting semaphore
shared_fd.h	File descriptor wrapper
signal.h	Signal & slot implementation
thread.h	Thread support
thread_annotations.h
timer.h	Generic timer
unique_fd.h	File descriptor wrapper that owns a file descriptor
utils.h	Miscellaneous utility functions
internal
converter
converter_dw100.h
converter_dw100_vertexmap.h
converter_v4l2_m2m.h	V4L2 M2M based converter
software_isp
benchmark.h
debayer_params.h
software_isp.h
swisp_stats.h
swstats_cpu.h
bayer_format.h	Class to represent Bayer formats and manipulate them
byte_stream_buffer.h	Managed memory container for serialized data
camera.h	Internal camera device handling
camera_controls.h	Controls for Camera instances
camera_lens.h	A camera lens controller
camera_manager.h	Internal camera manager support
camera_sensor.h	A camera sensor
camera_sensor_properties.h	Database of camera sensor properties
clock_recovery.h	Clock recovery - deriving one clock from another independent clock
control_serializer.h	Serialization and deserialization helpers for controls
control_validator.h	Abstract control validator
converter.h	Abstract converter
debug_controls.h	Helper to easily record debug metadata inside libcamera
delayed_controls.h	Helper to deal with controls that take effect with a delay
device_enumerator.h	Enumeration and matching of media devices
dma_buf_allocator.h
egl.h
formats.h	Types and helper functions to handle libcamera image formats
framebuffer.h	Internal frame buffer handling support
global_configuration.h
ipa_data_serializer.h	IPA Data Serializer
ipa_manager.h	Image Processing Algorithm module manager
ipa_module.h	Image Processing Algorithm module
ipa_proxy.h	IPA Proxy
ipc_pipe.h	IPC mechanism for IPA isolation
ipc_unixsocket.h	IPC mechanism based on Unix sockets
mapped_framebuffer.h	Frame buffer memory mapping support
matrix.h	Matrix class
media_device.h	Provide a representation of a Linux kernel Media Controller device that exposes the full graph topology
media_object.h	Provides a class hierarchy that represents the media objects exposed by the Linux kernel Media Controller APIs
media_pipeline.h	Provide a representation of a pipeline of devices using the Media Controller
pipeline_handler.h	Create pipelines and cameras from a set of media devices
process.h	Process object
pub_key.h	Public key signature verification
request.h	Internal support for request handling
shared_mem_object.h
source_paths.h	Identify the build and source path of a not-yet-installed library
sysfs.h	Miscellaneous utility functions to access sysfs
v4l2_device.h	Common base for V4L2 devices and subdevices
v4l2_pixelformat.h	V4L2 Pixel Format
v4l2_request.h	V4L2 Request
v4l2_subdevice.h	V4L2 Subdevice API
v4l2_videodevice.h	V4L2 Video Device
value_node.h	Data structure to manage tree of values
vector.h	Vector class
yaml_parser.h	A YAML parser helper
ipa
ipa_controls.h	Type definitions for serialized controls
ipa_interface.h	Image Processing Algorithm interface
ipa_module_info.h	Image Processing Algorithm module information
camera.h	Camera device handling
camera_manager.h	The camera manager
color_space.h	Class and enums to represent color spaces
controls.h	Framework to manage controls related to an object
fence.h	Definition of the Fence class
framebuffer.h	Frame buffer handling
framebuffer_allocator.h	FrameBuffer allocator
geometry.h	Data structures related to geometric objects
logging.h	Logging management
orientation.h	Image orientation definition
pixel_format.h	Libcamera pixel format
request.h	Describes a frame capture request to be processed by a camera
stream.h	Video stream for a Camera
transform.h	Enum to represent and manipulate 2D plane transforms
src
ipa
ipu3
algorithms
af.h
agc.h
algorithm.h
awb.h
blc.h	IPU3 Black Level Correction control
tone_mapping.h
ipa_context.h	Context and state information shared between the algorithms
module.h
libipa
agc_mean_luminance.h	Base class implementing mean luminance AEGC
algorithm.h	Algorithm common interface
awb.h	Base classes for AWB algorithms
awb_bayes.h	Implementation of bayesian auto white balance algorithm
awb_grey.h	Implementation of a grey world AWB algorithm
camera_sensor_helper.h	Helper class that performs sensor-specific parameter computations
colours.h	Functions to reduce code duplication between IPA modules
exposure_mode_helper.h	Helper class that performs computations relating to exposure
fc_queue.h	Queue of per-frame contexts
fixedpoint.h
histogram.h	Class to represent Histograms and manipulate them
interpolator.h	Helper class for linear interpolating a set of objects
lsc_polynomial.h	LscPolynomial class
lux.h	Helper class that implements lux estimation
module.h	IPA Module common interface
pwl.h	Piecewise linear functions
quantized.h	Quantized storage and Quantizer representations
v4l2_params.cpp	Helper class to populate an ISP configuration buffer compatible with the generic V4L2 ISP format
v4l2_params.h
libcamera
software_isp
debayer.h
debayer_cpu.h
debayer_egl.h
software_isp.cpp	Simple software ISP implementation
dma_buf_allocator.cpp	Dma-buf allocator
shared_mem_object.cpp	Helpers for shared memory allocations