Task 127: .DAT File Format
Task 127: .DAT File Format
1. List of Properties of the .DAT File Format Intrinsic to Its File System
The .DAT file extension is generic and does not correspond to a single standardized format. Various applications employ .DAT files with proprietary structures. For this analysis, the specifications are based on the DAT format used in the Metavision SDK by Prophesee, which is designed for storing decoded events from event-based vision systems. This format includes an ASCII header with key-value pairs, followed by binary data. The properties extracted from the header, which are intrinsic to the format's structure, are as follows:
- Data file containing: Specifies the type of events stored (e.g., "CD events").
- Date: The recording date and time in the format YYYY-MM-DD HH:MM:SS.
- Version: The version of the DAT format (e.g., "2").
- Width: The horizontal size of the image sensor array (e.g., "640").
- Height: The vertical size of the image sensor array (e.g., "480").
These properties are mandatory or optional as defined in the format, with "Data file containing" and "Version" being required.
2. Two Direct Download Links for .DAT Files
Given the generic nature of .DAT files, the following links provide direct downloads to sample .DAT files from public sources. Note that these may not conform to the specific Metavision DAT format used above but serve as examples of .DAT files:
- https://chirpmyradio.com/attachments/5597/CRT_Apollo_2000H_HAM_test.dat
- https://gitlab.onelab.info/getdp/getdp/-/raw/902a4cd14a74156ab7bc4d300539b0e387a1dde5/benchmarks/waveguides/waveguide3D_step.dat
3. Ghost Blog Embedded HTML JavaScript for Drag-and-Drop .DAT File Dump
The following is an embeddable HTML snippet with JavaScript suitable for integration into a Ghost blog post. It enables users to drag and drop a .DAT file, parses the header to extract the properties listed in section 1, and displays them on the screen. The code assumes the Metavision DAT format for parsing.
4. Python Class for .DAT File Handling
The following Python class can open a .DAT file (assuming the Metavision format), decode the header to read the properties, print them to the console, and write a new .DAT file with specified properties (including a minimal binary section for completeness).
import os
class DatFile:
def __init__(self):
self.properties = {}
def open_and_decode(self, filename):
if not os.path.exists(filename):
raise FileNotFoundError(f"File {filename} not found.")
with open(filename, 'rb') as f:
data = f.read()
# Parse header
lines = []
pos = 0
while pos < len(data) and data[pos] == 0x25: # '%'
nl_pos = data.find(b'\n', pos)
if nl_pos == -1:
break
line = data[pos + 1:nl_pos].decode('ascii').strip()
if line:
key, value = line.split(maxsplit=1)
self.properties[key] = value
pos = nl_pos + 1
def print_properties(self):
for key, value in self.properties.items():
print(f"{key}: {value}")
def write(self, filename):
with open(filename, 'wb') as f:
for key, value in self.properties.items():
f.write(b'% ' + key.encode('ascii') + b' ' + value.encode('ascii') + b'\n')
# Add minimal binary section (e.g., for CD events)
f.write(b'\x0C\x08') # Event type 12, size 8
# Example usage:
# dat = DatFile()
# dat.open_and_decode('sample.dat')
# dat.print_properties()
# dat.properties['Version'] = '3' # Modify if needed
# dat.write('new.dat')
5. Java Class for .DAT File Handling
The following Java class can open a .DAT file, decode the header to read the properties, print them to the console, and write a new .DAT file with specified properties.
import java.io.*;
import java.util.*;
public class DatFile {
private Map<String, String> properties = new HashMap<>();
public void openAndDecode(String filename) throws IOException {
File file = new File(filename);
if (!file.exists()) {
throw new FileNotFoundException("File " + filename + " not found.");
}
try (FileInputStream fis = new FileInputStream(file);
BufferedInputStream bis = new BufferedInputStream(fis)) {
byte[] data = new byte[(int) file.length()];
bis.read(data);
// Parse header
int pos = 0;
while (pos < data.length && data[pos] == 0x25) { // '%'
int nlPos = pos;
while (nlPos < data.length && data[nlPos] != 0x0A) nlPos++;
if (nlPos == data.length) break;
String line = new String(data, pos + 1, nlPos - pos - 1, "ASCII").trim();
if (!line.isEmpty()) {
String[] parts = line.split(" ", 2);
if (parts.length == 2) {
properties.put(parts[0], parts[1]);
}
}
pos = nlPos + 1;
}
}
}
public void printProperties() {
for (Map.Entry<String, String> entry : properties.entrySet()) {
System.out.println(entry.getKey() + ": " + entry.getValue());
}
}
public void write(String filename) throws IOException {
try (FileOutputStream fos = new FileOutputStream(filename)) {
for (Map.Entry<String, String> entry : properties.entrySet()) {
fos.write(("% " + entry.getKey() + " " + entry.getValue() + "\n").getBytes("ASCII"));
}
// Add minimal binary section
fos.write(new byte[] {0x0C, 0x08});
}
}
// Example usage:
// public static void main(String[] args) throws IOException {
// DatFile dat = new DatFile();
// dat.openAndDecode("sample.dat");
// dat.printProperties();
// dat.properties.put("Version", "3");
// dat.write("new.dat");
// }
}
6. JavaScript Class for .DAT File Handling
The following JavaScript class (for Node.js) can open a .DAT file, decode the header to read the properties, print them to the console, and write a new .DAT file. It uses the 'fs' module.
const fs = require('fs');
class DatFile {
constructor() {
this.properties = {};
}
openAndDecode(filename) {
if (!fs.existsSync(filename)) {
throw new Error(`File ${filename} not found.`);
}
const data = fs.readFileSync(filename);
// Parse header
let pos = 0;
while (pos < data.length && data[pos] === 0x25) { // '%'
let nlPos = data.indexOf(0x0A, pos);
if (nlPos === -1) break;
const line = data.slice(pos + 1, nlPos).toString('ascii').trim();
if (line) {
const [key, ...valueParts] = line.split(' ');
this.properties[key] = valueParts.join(' ');
}
pos = nlPos + 1;
}
}
printProperties() {
for (const [key, value] of Object.entries(this.properties)) {
console.log(`${key}: ${value}`);
}
}
write(filename) {
let header = '';
for (const [key, value] of Object.entries(this.properties)) {
header += `% ${key} ${value}\n`;
}
const binary = Buffer.from([0x0C, 0x08]);
fs.writeFileSync(filename, Buffer.concat([Buffer.from(header, 'ascii'), binary]));
}
}
// Example usage:
// const dat = new DatFile();
// dat.openAndDecode('sample.dat');
// dat.printProperties();
// dat.properties.Version = '3';
// dat.write('new.dat');
7. C++ Class for .DAT File Handling
The following C++ class can open a .DAT file, decode the header to read the properties, print them to the console, and write a new .DAT file with specified properties.
#include <iostream>
#include <fstream>
#include <string>
#include <map>
#include <sstream>
class DatFile {
private:
std::map<std::string, std::string> properties;
public:
void openAndDecode(const std::string& filename) {
std::ifstream file(filename, std::ios::binary);
if (!file.is_open()) {
throw std::runtime_error("File " + filename + " not found.");
}
std::string content((std::istreambuf_iterator<char>(file)), std::istreambuf_iterator<char>());
// Parse header
size_t pos = 0;
while (pos < content.size() && content[pos] == '%') {
size_t nlPos = content.find('\n', pos);
if (nlPos == std::string::npos) break;
std::string line = content.substr(pos + 1, nlPos - pos - 1);
std::istringstream iss(line);
std::string key, value;
iss >> key;
std::getline(iss >> std::ws, value);
if (!key.empty()) {
properties[key] = value;
}
pos = nlPos + 1;
}
}
void printProperties() const {
for (const auto& pair : properties) {
std::cout << pair.first << ": " << pair.second << std::endl;
}
}
void write(const std::string& filename) const {
std::ofstream file(filename, std::ios::binary);
if (!file.is_open()) {
throw std::runtime_error("Could not open file " + filename + " for writing.");
}
for (const auto& pair : properties) {
file << "% " << pair.first << " " << pair.second << "\n";
}
// Add minimal binary section
char binary[] = {0x0C, 0x08};
file.write(binary, sizeof(binary));
}
};
// Example usage:
// int main() {
// try {
// DatFile dat;
// dat.openAndDecode("sample.dat");
// dat.printProperties();
// dat.write("new.dat");
// } catch (const std::exception& e) {
// std::cerr << e.what() << std::endl;
// }
// return 0;
// }