LMP to TXT Converter

LMP to TXT Conversion Explained

Converting Game demo files (.LMP) to plain text files (.TXT) transforms a binary sequence of recorded player inputs into a human-readable log. People convert .LMP to .TXT to analyze speedrun data, verify player inputs, or extract metadata like the engine version, map number, and completion time.

When you convert .LMP to .TXT, you gain readability and searchability. You can read the exact movements, turns, and actions executed during every frame (tic) of the game. However, you lose the ability to play the file in the game engine. The main trade-off is binary efficiency versus human readability. This conversion is a bad idea if you want to watch the gameplay; for that, you must play the .LMP in the original game engine or record it to a video format like .MP4.

Typical Tasks and Users

• Speedrunners and Moderators: Tournament judges convert demo files to text to verify run legitimacy. They look for impossible input sequences that indicate cheating or spliced runs.
• Tool-Assisted Speedrun (TAS) Creators: TAS creators decompile .LMP files to .TXT, edit the specific frame inputs manually to optimize movement, and compile them back to .LMP.
• Game Engine Developers: Programmers working on custom source ports extract demo data to debug engine behavior and ensure demo sync compatibility.

Software & Tool Support

You cannot open an .LMP file directly in a text editor without seeing garbled characters. You need specific tools to parse the binary data into text.

• LMPC (LMP Compiler): A classic command-line tool hosted on GitHub that decompiles Doom and Quake .LMP files into readable text scripts, and compiles them back.
• Source Ports: Modern engines like DSDA-Doom and PrBoom+ include built-in debugging tools that can dump demo data to text files.
• Custom Scripts: Developers often use Python and its struct module to write custom parsers for specific .LMP versions.
• Text Editors: Once converted, you can view the .TXT file in Notepad++ or Visual Studio Code.

Pros and Cons of the Conversion

Pros:

• Transparency: Exposes the exact keystrokes, mouse movements, and game tics hidden inside the binary file.
• Editability: Allows precise, frame-by-frame editing of player inputs using standard text editors.
• Metadata Access: Makes it easy to read the header data, including the required game version, skill level, and multiplayer parameters.

Cons:

• File Size Bloat: A binary .LMP stores inputs in a few bytes per tic. A .TXT file uses multiple characters per tic, increasing the file size significantly.
• Breaks Playback: Game engines cannot read .TXT files as demos. You must recompile the text back to .LMP to watch it.
• Format Fragmentation: Different games and source ports use different binary structures, making accurate text extraction difficult.

Conversion Difficulties & Why Convert.Guru

The primary technical problem in converting .LMP to .TXT is the lack of a universal standard. An .LMP file from Doom 1.9 has a different byte structure than an .LMP from Boom, MBF, or Quake. A converter must read the binary header, identify the exact engine version, and apply the correct parsing logic for the input data (forward move, side move, turn angle, and action buttons). If the parser misidentifies the engine version, the resulting .TXT file will contain misaligned, garbage data.

Convert.Guru handles this binary parsing automatically. The platform identifies the correct engine header, maps the binary byte structure to the corresponding input values, and extracts the metadata cleanly. It provides an accurate, readable text log without requiring users to configure command-line decompilers or write custom Python scripts.

LMP vs. TXT: What is the better choice?

Which format should you choose?

Choose .LMP when you want to watch the gameplay, share a speedrun with the community, or run a demo in a compatible source port. It is the only format the game engine understands.

Choose .TXT when you need to analyze input data, verify the integrity of a speedrun, or read demo metadata without opening a game engine.

Avoid this conversion entirely if your goal is to upload a video to YouTube or share gameplay with non-technical users. In that case, play the .LMP file in the game and use screen recording software to capture it as a standard video file.

Conclusion

Converting .LMP to .TXT makes sense for technical analysis, speedrun verification, and tool-assisted speedrun creation. The biggest limitation to watch for is that the resulting text file cannot be played in the game engine without being recompiled back into a binary format. Convert.Guru is a reliable choice for this exact conversion because it correctly identifies the specific game engine header and accurately translates the binary tics into a clean, structured text log.