Guide to Automatic Game Replays in OBS

OBS Studio gives you complete control over your recording quality, audio tracks, and setup without extra bloat or subscriptions.

With a few settings, it can run quietly in the system tray on startup. Pairing it with Smart Capture for OBS takes care of the rest: automatically starting the replay buffer when a game launches and sorting saved clips into game-specific folders.

Here's the setup I use.

1. General Settings & Auto Startup

The goal is a set-and-forget setup where OBS stays out of the way:

1. Open OBS and head to Settings > General.
2. Under the General section:
   • Check Hide OBS windows from screen capture (ensures OBS never accidentally shows up in recordings).
3. Under the System Tray section:
   • Check Enable.
   • (Optional) Check Always minimize to system tray instead of task bar.
4. To start OBS automatically with Windows:

   • Press Win + R, type shell:startup, and press Enter.

   • Create a shortcut to obs64.exe inside the Startup folder.

   • Right-click the shortcut, select Properties, and append --minimize-to-tray --scene "Replay" (make sure this matches the scene name from Step 3) to the end of the Target field:

     "C:\Program Files\obs-studio\bin\64bit\obs64.exe" --minimize-to-tray --scene "Replay"

2. Encoder Options & Replay Buffer Setup

For local recording, CQP (Constant Quality) targets a consistent visual level rather than a fixed bitrate. It saves bandwidth during static menus and allocates more data when there is fast motion on screen.

If you prefer fixed buffer sizes without calculating RAM limits, CBR (Constant Bitrate) is a simpler alternative where OBS manages the buffer size automatically.

Step A: Configure Recording Settings

Head to Settings > Output and set Output Mode to Advanced.

Switch to the Recording tab (which applies to your replay buffer as well):

• Recording Path: Choose where you want your recordings and clips saved.
• Audio Track: Check 1 through 6 for multi-track audio (skip if you only want a single track).

NVIDIA GPUs (NVENC)

• Encoder: NVIDIA NVENC HEVC or AV1 (RTX 40-series) / H.264
• Rate Control: CQP
• CQ Level: 16 to 20 (Lower number = higher visual quality)
• Keyframe Interval: 2 s
• Preset: P5: Slow (Good Quality) or P6: Slower (Better Quality)
• Tuning: High Quality
• Multipass Mode: Two Passes (Quarter Resolution)

For more encoder details and tuning options, see the official NVIDIA NVENC OBS Guide.

AMD GPUs (AMF / VCE)

• Encoder: AMD HW H.265 / HEVC or AV1 (RX 7000-series) / H.264
• Rate Control: CQP
• CQ Level: 18 to 22 (Lower number = higher visual quality)
• Keyframe Interval: 2 s
• Preset: Quality

Step B: Turn on the Replay Buffer & Allocate Memory

1. In Settings > Output, switch over to the Replay Buffer tab.

2. Check Enable Replay Buffer.

3. Set Maximum Replay Time (Seconds) to your desired clip length.

4. Set Maximum Memory (Megabytes):

   Because CQP varies bitrates dynamically, OBS requires a memory ceiling to hold your rolling buffer. You can ballpark your needed RAM with this formula or use the reference table below:

   Estimated Bitrate (Mbps) x Replay Time (Seconds) / 8 x 1.25 (Headroom)

   Resolution & FPS	Est. Peak Bitrate	60s Buffer (1 min)	300s Buffer (5 mins)
   1080p60	~25 Mbps	~250-300 MB	~1200-1500 MB
   1440p60	~35 Mbps	~350-420 MB	~1700-2100 MB
   4K60	~65 Mbps	~650-800 MB	~3200-4000 MB

   (Note: If you use CBR, the Maximum Memory field is calculated automatically based on your set bitrate and time).

5. Go to Settings > Hotkeys, search for Replay Buffer, and assign a hotkey to Save Replay (e.g., F8 or a dedicated keybind).

6. (Optional) Under Settings > Advanced > Recording, you can customize Filename Formatting (e.g. %CCYY-%MM-%DD %hh.%mm.%ss).

3. Scene Setup & Multi-Track Audio

Step A: Set Up Sources in Your Scene

Build a dedicated recording scene with these sources:

1. Create a new scene and name it Replay.

2. Add a Game Capture source:

   • Mode: Leave as Capture any fullscreen application (or choose Capture specific window if needed).
   • Check Capture audio (BETA) to capture game audio directly.
   • Hook Rate: Leave at default (Normal) or change it to Fast if you want OBS to hook newly launched games more quickly.
   • Check Capture third-party overlays (such as Steam) if you want in-game achievements and notifications captured.

   Anti-Cheat & Black Screen: If a game with strict anti-cheat (like Valorant) gives you a black screen, add a Window Capture or Display Capture source instead.

3. (Optional for isolated audio) If you want separate tracks as shown below, add dedicated scene inputs:

   • Audio Input Capture (Microphone): Select your physical microphone.
   • Application Audio Capture (Voice Chat): Select your voice client (e.g. Discord.exe) and set Window Match Priority to Match title, otherwise find window of same executable.
   • Audio Output Capture (Desktop Audio): Keep Default or select the playback device you use as a safety fallback.

Step B: Separate Your Audio Tracks

By default, OBS captures all audio onto a single master track. Splitting them up gives you clean audio you can easily adjust or mute later when editing.

1. In Settings > Audio, set Desktop Audio, Desktop Audio 2, and Mic/Auxiliary Audio all to Disabled.

2. Right-click an empty space or the title bar of the Audio Mixer dock and select Advanced Audio Properties, then configure your tracks:

   Source	Track 1	Track 2	Track 3	Track 4	Track 5	Track 6
   Desktop Audio
   Game Capture
   Microphone
   Voice Chat

   • Track 1: Master track (Game + Mic + Voice Chat).
   • Track 2: Game audio.
   • Track 3: Microphone audio.
   • Track 4: Voice chat audio (e.g. Discord).
   • Track 5: Desktop fallback audio.
   • Track 6: Unassigned (spare slot for any custom audio you want to isolate, like music or a soundboard).

   Why Track 1 is key: Most platforms only play Track 1, so your raw clips work everywhere without editing.

3. Under Settings > Output > Recording, make sure checkboxes 1 through 6 are checked.

4. Under Settings > Output > Audio, bump the Audio Bitrate to 320 Kbps for each track.

4. Automatic Buffer & Sorting with Smart Capture

Smart Capture for OBS runs in the background, watches for running game executables, and takes care of sorting recordings into folders:

1. Get Smart Capture from the Smart Capture plugin page.
2. Run the quick installer (or drop the dll and data folder into your OBS obs-plugins directory).
3. Smart Capture will now automatically start the Replay Buffer whenever a game process is detected. When you hit your save hotkey, your clip lands straight inside a dedicated folder named after the game you were playing.

5. In-Game HUD with Status Overlay

Since OBS runs minimized in your tray, it's nice to have some quick visual feedback so you know your buffer is active and your clips actually saved.

If you want a lightweight in-game HUD, take a look at Status Overlay for OBS:

• Subtle Status Indicator: A minimal dot showing if replay buffer, recording, or streaming is live.
• On-Screen Notifications: Alerts for streaming (start/stop), recording (start/pause/stop), and replay buffer (start/save/stop) events.
• Hidden from Captures: Automatically excluded from streams, recordings, and saved clips.