feat(realtime): add preferredVideoCodec connect option#146
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Exposes a preferredVideoCodec ("h264" | "vp9") option on
realtime.connect() to control the local track publish codec.
VP9 publishes use a 2.6 Mbps cap; Safari remains pinned to vp8.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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| if (safariCodec && preferredVideoCodec) { | ||
| logger.warn("preferredVideoCodec ignored on Desktop Safari; using vp8"); | ||
| } |
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lets drop it from here, and mention this in the docs? devs will need to do ugly tricks to make this warning disappear so let's help them not have to
- Set VP9 max bitrate to 3 Mbps. - Disable simulcast only for VP9 (SVC); keep simulcast on for h264/vp8/av1. - Drop the Safari override warn; document the fallback on the schema field instead. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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Cursor Bugbot has reviewed your changes and found 1 potential issue.
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| }, | ||
| defaultVideoCodec: "h264", | ||
| defaultMaxVideoBitrateBps: 3_500_000, | ||
| vp9MaxVideoBitrateBps: 3_000_000, |
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VP9 bitrate config contradicts documented intent
Medium Severity
The vp9MaxVideoBitrateBps config is set to 3_000_000 (3.0 Mbps), but the PR description explicitly states "VP9 publishes get a 2.6 Mbps maxBitrate cap" and the test plan verifies maxBitrate === 2_600_000. The implemented value doesn't match the documented intent — either the config value or the PR description needs to be reconciled.
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Summary
preferredVideoCodec: "h264" | "vp9"torealtime.connect()options. Defaults toh264via existing config.maxBitratecap (newREALTIME_CONFIG.livekit.vp9MaxVideoBitrateBps); other codecs keep the 3.5 Mbps default.vp8; a warn log is emitted if a user value is ignored.livekit_server_codecquery param is untouched.packages/sdk/index.html) gets a codec dropdown in the publisher config section.Test plan
pnpm exec tsc --noEmitcleanpnpm test --run— 206/206 passingpackages/sdk/index.html, pickvp9, connect; verifyRTCRtpSender.getParameters().encodings[0].maxBitrate === 2_600_000and active codec is VP9 inchrome://webrtc-internalsh264(or default), confirmmaxBitrate === 3_500_000vp9, confirm warn log and thatvp8is published🤖 Generated with Claude Code
Note
Medium Risk
Changes WebRTC publish encoding (codec, bitrate, simulcast) on the realtime path; Safari override limits blast radius but wrong VP9 settings could affect stream quality or compatibility.
Overview
Adds optional
preferredVideoCodec(h264|vp9) onrealtime.connect()so callers can choose the LiveKit local camera publish codec; omitting it keeps the existing h264 default.Publish options now resolve codec explicitly: VP9 uses a 3 Mbps max bitrate (
vp9MaxVideoBitrateBps) and disables simulcast; other codecs keep 3.5 Mbps and simulcast. Desktop Safari still forces VP8 for publish (and thelivekit_server_codecquery param); user preference does not override that.The SDK test page adds a codec dropdown wired into connect for manual verification.
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