OBS Studio Introduction - Capture and Replay Buffer for Playtest VOD

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<strong>OBS Studio</strong> is the default <strong>free, open-source</strong> capture stack for indie playtests: full sessions, <strong>Replay Buffer</strong> “last N minutes,” and facilitator laptops on <strong>Windows 11</strong>. For <strong>2026</strong> fest ops, OBS is not “streaming software only”—it is the <strong>front door</strong> to <code>playtest-vod/inbox/</code> and <a href="/blog/local-whisper-transcription-pipeline-playtest-vod-triage-2026">local Whisper triage</a>.

This chapter orients <strong>facilitators and pipeline owners</strong> who already installed OBS and need <strong>receipt-grade capture</strong> before concat and ASR—not a full streaming tutorial.

Why this matters now

<strong>June 2026</strong> teams adopted Replay Buffer clips to avoid uploading hour-long sessions. Overnight <strong>Whisper batch</strong> jobs fail when:

• Replay saves <strong>video-only</strong> MKV (no audio stream).
• Fragments mix <strong>44.1 kHz</strong> and <strong>48 kHz</strong> without normalize.
• Concat runs before <strong>ffprobe</strong> proves monotonic timestamps.

Fixing Whisper weights does not help when <strong>OBS profile</strong> and <strong>ffmpeg normalize</strong> were never locked—see <a href="/help/obs-replay-buffer-export-zero-duration-audio-whisper-vod-triage-fix">zero-duration audio help</a>.

Who this chapter is for

• Contract facilitators under <a href="/courses/ai-powered-rpg-game/lessons/206-multi-channel-facilitator-contract-and-version-receipt-2026-rpg-live-ops">Lesson 206 facilitator SOW</a>
• Engineers wiring <strong><code>concat_ok</code></strong> (<a href="/courses/ai-powered-rpg-game/lessons/200-playtest-vod-concat-ok-gate-before-whisper-batch-triage-2026-rpg-live-ops">Lesson 200</a>)
• Producers requiring <strong><code>audio_stream_ok</code></strong> before cloud API spend

<strong>Time:</strong> ~<strong>10 minutes</strong> to read; <strong>one evening</strong> for the normalize preflight chapter.

Core concepts (playtest-focused)

| Concept | What it means for triage |

|---------|--------------------------|

| <strong>Profile</strong> | Named settings bundle—Replay must use the <strong>same</strong> profile as audio checklist |

| <strong>Replay Buffer</strong> | Rolling capture; Save writes MKV to disk |

| <strong>Desktop Audio / Mic</strong> | Tracks muxed into Replay—misconfig → silent file |

| <strong>ffprobe</strong> | Stream/duration truth before Whisper |

| <strong>concat demuxer</strong> | Merges normalized WAVs—requires uniform sample rate |

What OBS is (and is not)

OBS <strong>is</strong>:

• <strong>Low-latency capture</strong> for repro clips and playtest nights
• <strong>Replay Buffer</strong> for “last 2 minutes” bug evidence
• A <strong>facilitator-standard</strong> tool listed in <a href="/blog/16-free-obs-ffmpeg-silero-playtest-vod-concat-whisper-batch-tools-2026">16 free OBS/ffmpeg tools</a>

OBS <strong>is not</strong>:

• A replacement for <strong>Whisper</strong> or <strong>Silero VAD</strong>—extract/normalize still runs in ffmpeg
• A <strong>BUILD_RECEIPT</strong> editor—receipts live in JSON beside upload logs
• Guaranteed <strong>concat_ok</strong> without a <strong>normalize preflight</strong> chapter

Where to go next

• <strong>Normalize preflight:</strong> <a href="/guides/obs-studio?chapter=obs-studio-replay-buffer-fragment-normalize-before-ffmpeg-concat-preflight-2026-preflight">Replay Buffer fragment normalize before ffmpeg concat</a>
• <strong>Evening pipeline:</strong> <a href="/blog/your-first-obs-replay-buffer-ffmpeg-concat-before-whisper-playtest-batch-one-evening-2026-beginner-pipeline">Your First OBS Replay Buffer ffmpeg concat</a>
• <strong>Silent MKV fix:</strong> <a href="/help/obs-replay-buffer-export-zero-duration-audio-whisper-vod-triage-fix">OBS Replay Buffer zero-duration audio help</a>

<strong>Sign-off:</strong> Treat OBS as part of <strong>release evidence</strong>, not a personal streaming preset—profile lock is a <strong>contract requirement</strong>, not optional.