C++ 读取二进制lvx格式点云文件按偏移量解析数据并保存为pcd格式，不依赖SDK

读取二进制lvx格式点云文件并按偏移量解析数据，并保存为pcd格式，可以通过以下步骤实现：

1. 打开lvx文件，读取文件头，获取点云数据的偏移量和点云数据的总大小。

2. 读取点云数据的偏移量和长度信息，根据偏移量和长度解析点云数据。

3. 将点云数据保存为pcd格式文件。

以下是示例代码：

#include <iostream>
#include <fstream>
#include <string>
#include <vector>

using namespace std;

#pragma pack(push, 1)
struct PointXYZRGB
{
    float x;
    float y;
    float z;
    uint8_t r;
    uint8_t g;
    uint8_t b;
};
#pragma pack(pop)

int main()
{
    string lvx_file_path = "input.lvx";
    string pcd_file_path = "output.pcd";

    // 打开lvx文件，读取文件头
    ifstream lvx_file(lvx_file_path, ios::binary);
    if (!lvx_file.is_open()) {
        cerr << "Error: Unable to open file " << lvx_file_path << endl;
        return -1;
    }
    lvx_file.seekg(80, ios::beg); // 文件头固定长度为80字节
    uint64_t data_offset = 0;
    uint64_t data_size = 0;
    lvx_file.read((char*)&data_offset, sizeof(data_offset));
    lvx_file.read((char*)&data_size, sizeof(data_size));

    // 读取点云数据
    lvx_file.seekg(data_offset, ios::beg);
    vector<PointXYZRGB> points;
    while (lvx_file.tellg() - data_offset < data_size) {
        uint32_t length = 0;
        lvx_file.read((char*)&length, sizeof(length));
        if (length != sizeof(PointXYZRGB)) {
            cerr << "Error: Invalid point size" << endl;
            return -1;
        }
        PointXYZRGB p;
        lvx_file.read((char*)&p, sizeof(p));
        points.push_back(p);
    }
    lvx_file.close();

    // 将点云数据保存为pcd格式文件
    ofstream pcd_file(pcd_file_path);
    pcd_file << "# .PCD v0.7 - Point Cloud Data file format\n";
    pcd_file << "VERSION 0.7\n";
    pcd_file << "FIELDS x y z rgb\n";
    pcd_file << "SIZE 4 4 4 4\n";
    pcd_file << "TYPE F F F U\n";
    pcd_file << "COUNT 1 1 1 1\n";
    pcd_file << "WIDTH " << points.size() << endl;
    pcd_file << "HEIGHT 1\n";
    pcd_file << "POINTS " << points.size() << endl;
    pcd_file << "DATA ascii\n";
    for (const auto& p : points) {
        uint32_t rgb = (p.r << 16) | (p.g << 8) | p.b;
        pcd_file << p.x << " " << p.y << " " << p.z << " " << rgb << endl;
    }
    pcd_file.close();

    return 0;
}

注意：此代码仅供参考，具体实现可能因文件格式和数据结构而异。