A Fabric addon for Flashback that drastically speeds up video export — without quality loss.
Validated across hundreds of real anonymous exports on Windows (primary platform), macOS and Linux. Export failure rate ~1%, and every observed failure was external (not enough RAM allocated for very long replays, or the game closed mid-export) — never a regression introduced by FlashbackTurbo itself.
Patches Flashback's export pipeline via Mixin to replace serial, low-tuned operations with parallel ones:
h264_nvenc, h264_qsv, h264_videotoolbox, libopenh264)mc.level race)libopenh264 encoder, redirects it to a hardware encoder (NVENC/QSV) when one is available. Fail-safe, SSIM ≥ 0.99.All hooks are opt-in via config/flashbackturbo.json and default to safe values.
Real 1.21.11 replay, 10-second slice at 1920×1080 (603 frames):
| Mode | Total | Per frame |
|---|---|---|
| Vanilla | 96 081 ms | 159 ms |
| Turbo | 8 774 ms | 14 ms |
10.95× end-to-end.
| Platform · encoder | Median export |
|---|---|
Windows · NVIDIA h264_nvenc |
~8.5 s (60 fps) |
Windows · Intel h264_qsv |
~23 s (60 fps) |
macOS · h264_videotoolbox |
~26 s (30 fps) |
Software fallback libopenh264 |
~55 s |
Lossless PNG output — zlib level only changes file size, decoded pixels are bit-identical. The FFmpeg threading tunes don't change the encoded bitstream.
FlashbackTurbo sends anonymous usage telemetry (PostHog) to prioritise improvements: a random local UUID, no username / IP / file paths, sanitised exception messages. Fully fail-safe and opt-out — set "enableTelemetry": false in the config.
Server-side Flashback replay recording for Paper - zero dependencies, Folia-ready, with a rolling clip system. No client mod required for recorded players.
Server-side Flashback replay recording for Paper - zero dependencies, Folia-ready, with a rolling clip system. No client mod required for recorded players.
