Audio

Tick Record audio in the window and pick the source — Mic, Desktop (system sound), or Both (mixed into one track) — or in code:

from castmane.config import AppConfig
cfg = AppConfig(audio_enabled=True)  # default mic
# system sound instead:
# cfg = AppConfig(audio_enabled=True, audio_mode="desktop")
# mic + system sound mixed:
# cfg = AppConfig(audio_enabled=True, audio_mode="both")

List devices with pactl list short sources. “Desktop” auto-detects the first .monitor source; paste a device name into the desktop-source field (or audio_desktop_source) when auto-detection picks the wrong sink. Audio is encoded as AAC (avenc_aac on Wayland, aac on X11) into the same crash-safe file, so a kill -9 recording and its MP4 remux both keep the audio track.

Quiet system sound?

Monitor sources have no mic-style input boost, so system audio can sound much fainter than mic recordings. Raise the gain in the window (%) or in code (AppConfig(audio_gain=2.0) ~ +6 dB, 3.0 ~ +9.5 dB). Stay at or below 5.0 to avoid clipping.