Is there VBR for egress recordings?
# ask-aib
busy-elephant-27084
03/27/2026, 6:21 PMIs there VBR for egress recordings?
✅ 1
t
tall-airline-16756
03/27/2026, 6:21 PMThanks for reaching out, Roni. I'm an AI assistant and I'm here to help. Give me a moment while I research this topic.
tall-airline-16756
03/27/2026, 6:22 PMThanks — you're asking whether LiveKit egress recordings support Variable Bit Rate (VBR). I don't have confirmation about VBR availability right now, so I have a couple quick questions to narrow this down so I can give a precise answer or the best workaround:
• Do you mean VBR for the recorded file produced by egress (e.g., MP4/WEBM output), or VBR for live-encoded outgoing streams during egress?
• Which output format/container are you using or planning to use for recordings (MP4, WebM, MKV, or a raw stream)?
• Are you using any custom encoder parameters or a cloud-hosted egress (hosted by LiveKit) versus self-hosted egress setup?
If you tell me those details I can:
• Confirm whether VBR is supported for that specific recording path, or
• Suggest an alternative (for example, encoding after recording with VBR or changing container/encoder settings) and give concrete steps., with interactive elements
b
busy-elephant-27084
03/27/2026, 6:23 PM1. yes during egress
2. MP4
3. Hosted by livekit.
t
tall-airline-16756
03/27/2026, 6:23 PMThanks — you asked whether LiveKit’s hosted egress uses Variable Bitrate (VBR) for MP4 recordings.
Short answer: VBR for MP4 egress recordings is not confirmed. LiveKit’s hosted egress produces MP4 files and wraps H.264 tracks into MP4, but the egress behavior shows fixed/average bitrate targets rather than an exposed VBR mode. The egress service uses GStreamer under the hood (which can do VBR), but LiveKit does not document VBR as a configurable or default option for hosted MP4 recordings.
If you need VBR output, here are two practical options you can consider:
• Post-process the recorded MP4: download the MP4 from egress storage and re-encode it with your preferred VBR settings using ffmpeg or another encoder.
• Self-hosted egress (if feasible): run your own egress instance where you can control GStreamer/encoder parameters and enable VBR for MP4 output.
If you’d like, I can:
• Give an ffmpeg command to convert an MP4 to VBR settings tailored to your target quality/bitrate.
• Outline the configuration points you’d need to change if you evaluate self-hosted egress.
Which option would you prefer?
Sources: Universal Egress | LiveKit | Universal Egress | LiveKit | Bringing Zoom's end-to-end optimizations to WebRTC | LiveKit | An introduction to WebRTC Simulcast | LiveKit | livekit/livekit_composite | DeepWiki, with interactive elements