STT ffmpeg architecture mismatch on Apple Silicon: Rosetta x86_64 ffmpeg causes silent audio decode issues
brain-distill · confidence medium · status active
tags: infra lessons
On Aug 8 2026, the control-plane audit found that the Hermes STT (speech-to-text) resolver was selecting /usr/local/bin/ffmpeg, which is an x86_64 binary running under Rosetta on Apple Silicon (ARM). This caused architecture mismatch issues in audio processing. The fix was to add a native static ffmpeg resolver path that points to an ARM-native ffmpeg binary. Lesson: always verify the architecture of ffmpeg (file /usr/local/bin/ffmpeg) when configuring STT on Apple Silicon. Prefer a native ARM ffmpeg from Homebrew or a static build; Rosetta-translated ffmpeg causes silent corruption or performance degradation in audio decode.
Sources:
health-remediation.log:2026-08-08T04:02:00Z