Two follow-ups from the creator's lip-sync observation. 1. Audio still slept a fixed 50 ms per chunk — the same "sleep on top of the work" fault fixed for video an hour ago, left in place. Every chunk's read cost was added, so a clip's audio fell progressively behind its picture: small per chunk, unbounded over a long clip. It now uses the same deadline pacer, so audio and video advance on the same wall clock. 2. The preview pane is NOT the compositor. "Preview looks great" proves the decode and the preview bitmap; the recording and stream are blitted by SceneCompositor. `MediaCompositeOutputTests` renders a keyed video layer over a background through the real compositor and asserts the two things that matter: keyed (alpha 0) pixels let the background through, and the subject half covers it. So "green screen removed" is now proven in the output path, not just the pane. Also: a round-clipped video layer had no preview trigger (only webcam+Round existed), so it would render in the output and be invisible in the pane. Same unit-circle path now covers it. Tests: 16 scoped (pacer, real-clip rate + keying, composite output, decode pacing, alert pacing) green. FULL SUITE NOT RUN — the machine is in use: two runs under load aborted in the WPF test host (HWND subclass crash) and one hit the 15-minute cap. Re-run scripts/verify.sh in a quiet window.
LlamaCasty
A free, open-source Windows app for streaming live to YouTube and recording to your PC. Native Windows (C# / WPF / .NET 8). Website: https://llamacasty.com
Why I built it
I'm Gramps. I've been gaming since 1981, and these days I stream The Division 2 on YouTube.
When I started streaming, I did what everybody does: I installed the big, general-purpose streaming tools. They're excellent software — powerful, flexible, and built to handle every platform, every camera rig, and every plugin anyone has ever dreamed up. That breadth is exactly what makes them great, and it's also what makes them a lot to learn. Before my first stream I was reading setup guides, picking encoders, balancing audio by hand, and wiring up scenes from scratch. The tools were ready for anything. I just wanted to go live.
Most streamers I talk to are in the same spot. They don't need a tool for every platform and every setup — they need one that's ready for theirs. So I built LlamaCasty around three choices:
- One platform, done properly. LlamaCasty streams to YouTube and only YouTube. That focus lets it be built around how YouTube Live actually works — your channel, your chat, Super Chats and memberships, Shorts-style vertical video, and the YouTube Partner Program — instead of treating YouTube as one destination among many.
- Ready the moment you open it. Five scenes (Starting, Live, BRB, Chat, Ending) are set up, your game and voice are balanced with auto-ducking and voice polish built in, and YouTube's settings are filled in. You arrange things by dragging them, then press Go Live.
- Calm while you're live. A private Test Stream to practice, a layout that locks while you're on air, and warnings only when YouTube reports a real problem.
The general-purpose tools are the right choice when you need everything. LlamaCasty is for when you just want to get your show on air.
Free, and the paid edition
The free version is the whole app, not a trial: every feature, every scene, every overlay, no watermark, no LlamaCasty account, and nothing in your stream advertising us. It stays free.
A paid edition exists for creators who need more output quality — free streams and records at up to 720p30, and Pro unlocks the higher tiers. No feature is ever gated behind it. The app shows the current price at the point of sale; the website deliberately does not.
If it earns a spot in your setup and you'd like to say thanks, there's a coffee jar and a merch store linked from https://llamacasty.com. Completely optional, never expected, and the app will never ask.
How it's built
LlamaCasty is built through AI-assisted pair programming, under the direction of a developer with decades of experience. Architecture, product direction, and quality gates are human-owned; AI speeds up the implementation. The repo's memory map (below) is how that collaboration stays honest from one session to the next.
Requirements
- 64-bit Windows 10 or 11. (The bundled FFmpeg and ONNX Runtime are 64-bit only.)
- A YouTube channel, to stream. LlamaCasty links an existing channel with "Sign in with Google" — it doesn't create accounts. Recording to an .mp4 works without signing in.
- Working sound in Windows. Desktop and game audio come from your default output automatically; you choose your mic in the app. LlamaCasty doesn't diagnose or repair Windows audio — if it doesn't sound right in Windows, fix it there first.
Build from source
The internal project, assembly, and namespace names are still ytLive (the app was renamed to
LlamaCasty; the internals weren't). Building needs Windows and the .NET 8 SDK.
-
Fetch the bundled FFmpeg (not in git — ~135 MB, pinned and SHA-256-verified):
scripts/fetch-ffmpeg.sh -
Add your own Google OAuth client.
Helpers/OAuthCredentials.csis gitignored. Create a "Desktop app" OAuth client with the YouTube Data API v3 enabled in Google Cloud Console, then:namespace ytLive.Helpers; public static class OAuthCredentials { public const string ClientId = "your-client-id.apps.googleusercontent.com"; public const string ClientSecret = "your-client-secret"; } -
Build and run:
dotnet build ytLive.csproj dotnet run --project ytLive.csproj
Version roadmap
v1 is the finished product (no v1.x releases are planned). Everything still in the queue lands
in v1; anything not on the feature list is on the "Out of product — permanently" list in
TASKS.md — read that before asking for a feature.
What v1 ships: the five-scene control surface, webcam + screen capture, media + web + text sources, chat on stream, the social bar, mic/desktop audio with auto-ducking and TRAX background music, local recording, quality tiers including vertical 9:16, one-click go-live + scheduling, stream resilience, monetization awareness (YPP tracker), animated alerts, and webcam background removal and blur — every feature in the free tier, with a paid edition that buys output quality.
Structure
| Path | Role |
|---|---|
Models/ |
Scene, Source, WebcamSceneConfig, SceneElement, SceneCatalog, QualityOption, StreamConfig/Health, chat, Socials, BroadcastMetadata, Music, MicStatus, BackgroundEffect |
ViewModels/ |
MainViewModel (partial classes per area) + dialogs: GoLive, CameraPicker, MicPicker, HotkeyConfig, Socials, LiveBroadcastForm |
Services/ |
YouTube (OAuth, streams/broadcasts, chat polling), LayoutStore (SQLite), capture (camera/screen-capture/media-file via FFmpeg), SceneCompositor + FramePump, FFmpeg encoder + RTMP, audio pipeline (WASAPI loopback + mic, mixer, filters, ducker, limiter, TRAX), background effects (ONNX person segmentation), SocialValidator, notifications, hotkeys, SceneGraph, ChatOverlayLayer |
Helpers/ |
ViewModelBase, RelayCommand, ImageCache, AppLog, TokenStore (DPAPI), OAuthCredentials (gitignored), converters |
Themes/ |
Controls.xaml — the dark-theme control styles, merged once in App.xaml |
MainWindow.xaml |
Dark-theme control surface: thumbnails + central preview, two-state left panel (layers/properties ↔ live chat), top bar, footer |
tools/ |
Offline helper tools (e.g. selfie-seg/ — converts and verifies the background-effects model) |
Docs (memory map)
schema.md defines the conventions; ai.md is the AI/session guide; TASKS.md is the task
queue; HANDOFF.md is the current state. Each code directory carries an index.md.
License
LlamaCasty is proprietary commercial software — see LICENSE for the full End User
License Agreement. The free tier streams and records at an output profile of up to 921,600
pixels at 30 fps (720p30 landscape, 720×1280 vertical); a paid licence unlocks every shipped tier,
including 1080p60. Prices, entitlement and channels: docs/ai/commercial.md.
Earlier development builds were published under GPL-3.0 and remain covered by that licence for the versions that shipped under it; nothing here revokes that.
Third-party components and their licences are listed in
THIRD-PARTY-NOTICES.txt, which ships with the app and is shown in its
About screen. Your data and privacy are described in PRIVACY.md.

