steamclipconverter

Convert Steam’s raw DASH clips (folders like fg_294100_20250828_124021 containing a session.mpd) into MP4 files using ffmpeg. Result files will be like

RimWorld-20250828-124021.mp4

Features

• Recursive scan for clip folders like fg_<appid>_<YYYYMMDD>_<HHMMSS>
• MPD-based remux: runs ffmpeg -i session.mpd -map 0:v:0 -map 0:a:0? -c copy -movflags +faststart
• Smart naming: GameName-YYYYMMDD-HHMMSS.mp4 (game name from appmanifest_<appid>.acf, fallback to AppID)
• Correct timestamps (UTC): output file’s modified time is set to the clip’s record start in UTC (Steam encodes UTC in the folder name)
• Filtering: --gameId 294100 (repeatable) to convert selected games only
• Cleanup: --delete-after removes the fg_* directory and the corresponding the clip_* directory. Note: please restart Steam after delete clip, otherwise Steam will try to load these deleted clips.
• Cross‑platform Steam roots: macOS, Linux, Windows (sane defaults; you can override with --input)

Requirements

• ffmpeg in your PATH.

Quick installs:

# macOS
brew install ffmpeg

# Ubuntu/Debian
sudo apt-get update && sudo apt-get install -y ffmpeg

# Windows (PowerShell)
winget install Gyan.FFmpeg

Install

From crates.io (recommended)

cargo install steamclipconverter --locked

From source

git clone https://github.com/qiaoruntao/steamclipconverter
cd steamclipconverter;
cargo build --release
./target/release/steamclipconverter --help

Prebuilt binaries(not recommended)

These files are not signed and cannot run on openbox.

Usage

TL;DR

# Simplest: use default options and converted mp4 occurred in current directory
steamclipconverter

# Or pass flags explicitly
steamclipconverter --input "/path/to/Steam/userdata" --output "/path/to/out"

If you provide no arguments, the tool will warn and default to scanning your OS-specific Steam userdata:

• macOS: ~/Library/Application Support/Steam/userdata
• Linux: ~/.local/share/Steam/userdata
• Windows: C:\Program Files (x86)\Steam\userdata

Override anytime with --input.

CLI reference

How it works (straight talk)

1. Find clips – Recursively locate directories named fg_<appid>_<YYYYMMDD>_<HHMMSS>.
2. Check MPD – Ensure session.mpd exists inside each fg_* directory.
3. Resolve game name – Read steamapps/appmanifest_<appid>.acf from discovered Steam libraries (libraryfolders.vdf on all OSes). If missing, use the AppID.
4. Mux – Call ffmpeg on the local session.mpd and stream copy the first video + optional audio to MP4. No re-encode.
5. Timestamp – Set the output file’s mtime to the record start (UTC) parsed from the folder name (Steam stores UTC in fg_<...>_YYYYMMDD_HHMMSS).
6. (Optional) Cleanup – If --delete-after, remove the converted fg_* folder; if it was the only subdir in its parent video/, remove the clip_* grandparent too.

About this common FFmpeg message

[dash] Error when loading first fragment of playlist

Steam’s MPDs sometimes list extra Representations whose first fragment isn’t present (mismatched numbering, missing audio, etc.). FFmpeg drops the bad one and continues with a valid stream. The output is fine; you can safely ignore this warning.

Examples

Convert everything under your Steam userdata, write to Desktop:

steamclipconverter --input "$HOME/Library/Application Support/Steam/userdata" \
                   --output "$HOME/Desktop/SteamClips"

Only convert RimWorld (294100) and Dota 2 (570):

steamclipconverter --input "$HOME/.local/share/Steam/userdata" \
                   --gameId 294100 --gameId 570

Convert then delete the source clip folders:

steamclipconverter --input "/path/to/Steam/userdata" --delete-after

Expected folder layout

.../clip_294100_20250828_124021/
  └─ video/
     └─ fg_294100_20250828_124021/
        ├─ session.mpd
        ├─ init-stream0.m4s
        ├─ chunk-stream0-00001.m4s
        ├─ ...
        ├─ init-stream1.m4s         # (optional)
        └─ chunk-stream1-00001.m4s  # (optional)

Only folders starting with fg_ are processed. If audio is missing, the MP4 will be video‑only.

References / Prior art

• Python original that inspired this approach (stitch + remux):
  https://github.com/Nastas95/SteamClip/blob/main/steamclip.py

• Handy explanation of Steam’s clip structure & extracting:
  https://gist.github.com/safijari/afa41cb017eb2d0cadb20bf9fcfecc93

• Community deep-dive on Steam Deck recordings:
  https://www.reddit.com/r/SteamDeckTricks/comments/1dpj1zv/game_recording_how_it_works_and_how_you_can_get/

License

MIT or Apache-2.0 (your call). Not affiliated with Valve/Steam.