/* SPDX-License-Identifier: LGPL-2.1-or-later */ /* * Copyright (C) 2021, Ideas on Board Oy * * image.cpp - Multi-planar image with access to pixel data */ #include "image.h" #include <assert.h> #include <errno.h> #include <iostream> #include <map> #include <string.h> #include <sys/mman.h> #include <unistd.h> using namespace libcamera; std::unique_ptr<Image> Image::fromFrameBuffer(const FrameBuffer *buffer, MapMode mode) { std::unique_ptr<Image> image{ new Image() }; assert(!buffer->planes().empty()); int mmapFlags = 0; if (mode & MapMode::ReadOnly) mmapFlags |= PROT_READ; if (mode & MapMode::WriteOnly) mmapFlags |= PROT_WRITE; struct MappedBufferInfo { uint8_t *address = nullptr; size_t mapLength = 0; size_t dmabufLength = 0; }; std::map<int, MappedBufferInfo> mappedBuffers; for (const FrameBuffer::Plane &plane : buffer->planes()) { const int fd = plane.fd.get(); if (mappedBuffers.find(fd) == mappedBuffers.end()) { const size_t length = lseek(fd, 0, SEEK_END); mappedBuffers[fd] = MappedBufferInfo{ nullptr, 0, length }; } const size_t length = mappedBuffers[fd].dmabufLength; if (plane.offset > length || plane.offset + plane.length > length) { std::cerr << "plane is out of buffer: buffer length=" << length << ", plane offset=" << plane.offset << ", plane length=" << plane.length << std::endl; return nullptr; } size_t &mapLength = mappedBuffers[fd].mapLength; mapLength = std::max(mapLength, static_cast<size_t>(plane.offset + plane.length)); } for (const FrameBuffer::Plane &plane : buffer->planes()) { const int fd = plane.fd.get(); auto &info = mappedBuffers[fd]; if (!info.address) { void *address = mmap(nullptr, info.mapLength, mmapFlags, MAP_SHARED, fd, 0); if (address == MAP_FAILED) { int error = -errno; std::cerr << "Failed to mmap plane: " << strerror(-error) << std::endl; return nullptr; } info.address = static_cast<uint8_t *>(address); image->maps_.emplace_back(info.address, info.mapLength); } image->planes_.emplace_back(info.address + plane.offset, plane.length); } return image; } Image::Image() = default; Image::~Image() { for (Span<uint8_t> &map : maps_) munmap(map.data(), map.size()); } unsigned int Image::numPlanes() const { return planes_.size(); } Span<uint8_t> Image::data(unsigned int plane) { assert(plane <= planes_.size()); return planes_[plane]; } Span<const uint8_t> Image::data(unsigned int plane) const { assert(plane <= planes_.size()); return planes_[plane]; }