LogCutter.py

Allows you to cut any log and copies the header into, etc into the cut file.  has a basic ui in tkinter. 

Since I’ve seen this asked for quite a bit, makes sense to make it part of the toolset. 

Rename as needed, etc.

pyulog/LogCutter.py

@@ -0,0 +1,174 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2024 Applied Aeronautics. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+/**
+ * @AA-LogCutter.py
+ * PX4 ULG Log File Splitter
+ *
+ * @author Ryan Johnston <rjohnston@AppliedAeronautics.com>
+ */
+
+
+
+import tkinter as tk
+from tkinter import filedialog, simpledialog, messagebox
+import os
+import struct
+
+def read_ulog_header_and_definitions(file_path):
+    try:
+        print(f"Reading ULog header and definitions from {file_path}")
+        with open(file_path, 'rb') as f:
+            magic_bytes = f.read(8)
+            print(f"Magic bytes: {magic_bytes}")
+            if magic_bytes != b'\x55\x4c\x6f\x67\x01\x12\x35\x01':
+                raise ValueError("Invalid ULog file format.")
+
+            version = f.read(1)
+            timestamp = f.read(8)
+            print(f"Version: {version}, Timestamp: {timestamp}")
+
+            header_length_bytes = f.read(2)
+            header_length = struct.unpack('<H', header_length_bytes)[0]
+            print(f"Header length: {header_length}")
+
+            remaining_header_length = header_length - 17
+            header_messages = f.read(remaining_header_length)
+            print(f"Read {remaining_header_length} bytes of header messages")
+
+            full_header = magic_bytes + version + timestamp + header_length_bytes + header_messages
+
+            definitions = b''
+            while True:
+                msg_header = f.read(3)
+                if not msg_header:
+                    print("End of file reached unexpectedly while reading definitions.")
+                    break
+
+                msg_size = struct.unpack('<H', msg_header[:2])[0]
+                msg_type = msg_header[2:3]
+
+                message_data = f.read(msg_size)
+                definitions += msg_header + message_data
+                print(f"Read message type: {msg_type}, size: {msg_size}")
+
+                if msg_type == b'D':
+                    print("Reached the start of the data section.")
+                    break
+
+            rest_of_file = f.read()
+            print(f"Read {len(rest_of_file)} bytes of data section.")
+
+        return full_header, definitions, rest_of_file
+
+    except Exception as e:
+        print(f"Error reading ULog header and definitions: {e}")
+        raise
+
+
+def cut_file(file_path, percentage, save_path):
+    try:
+        print(f"Cutting file {file_path} at {percentage}% and saving to {save_path}")
+
+        header, definitions, rest_of_file = read_ulog_header_and_definitions(file_path)
+        data_section = rest_of_file
+
+        data_size = len(data_section)
+        cut_size = int(data_size * (percentage / 100.0))
+        print(f"Data size: {data_size}, Cut size: {cut_size}")
+
+        part1_data = data_section[:cut_size]
+        part2_data = data_section[cut_size:]
+
+        save_part1_path = f"{save_path}_part1.ulg"
+        print(f"Saving first part to {save_part1_path}")
+        with open(save_part1_path, 'wb') as f:
+            f.write(header + definitions + part1_data)
+        print(f"Saved first part successfully.")
+
+        if part2_data:
+            save_part2_path = f"{save_path}_part2.ulg"
+            print(f"Saving second part to {save_part2_path}")
+            with open(save_part2_path, 'wb') as f:
+                f.write(header + definitions + part2_data)
+            print(f"Saved second part successfully.")
+            messagebox.showinfo("Success", f"Files saved:\n{save_part1_path}\n{save_part2_path}")
+        else:
+            messagebox.showinfo("Success", f"File saved:\n{save_part1_path}")
+
+    except Exception as e:
+        print(f"Error cutting file: {e}")
+        messagebox.showerror("Error", f"An error occurred: {e}")
+
+
+def ask_percentage():
+    percentage = simpledialog.askfloat("Cut Percentage", "Enter the percentage to cut the file at (0-100):", minvalue=0, maxvalue=100)
+    print(f"User entered percentage: {percentage}")
+    return percentage
+
+
+def save_file():
+    save_path = filedialog.asksaveasfilename(defaultextension=".ulg", filetypes=[("PX4 Log Files", "*.ulg"), ("All Files", "*.*")])
+    print(f"User selected save path: {save_path}")
+    return save_path
+
+
+def select_file():
+    file_path = filedialog.askopenfilename(filetypes=[("PX4 Log Files", "*.ulg"), ("All Files", "*.*")])
+    print(f"User selected file: {file_path}")
+
+    if file_path:
+        percentage = ask_percentage()
+        if percentage is not None:
+            save_path = save_file()
+            if save_path:
+                cut_file(file_path, percentage, save_path)
+            else:
+                messagebox.showwarning("No Save Path", "No save path selected. Operation cancelled.")
+        else:
+            messagebox.showwarning("No Percentage", "No percentage entered. Operation cancelled.")
+    else:
+        messagebox.showwarning("No File Selected", "No file selected. Operation cancelled.")
+
+
+def create_app():
+    root = tk.Tk()
+    root.title("PX4 Log Cutter")
+
+    open_button = tk.Button(root, text="Open PX4 Log File", command=select_file)
+    open_button.pack(pady=20)
+
+    root.mainloop()
+
+
+if __name__ == "__main__":
+    create_app()