✨(backend) add default video codec on apiConfig struct

Co-authored-by: David <60177543+davd-gzl@users.noreply.github.com>

CHANGELOG.md

@@ -8,6 +8,10 @@ and this project adheres to
 
 ## [Unreleased]
 
+### Added
+
+- ✨(backend) make the LiveKit default video codec configurable
+
 ### Changed
 
 - 📈(frontend) include LiveKit SIDs in the connection analytics event

src/backend/core/api/__init__.py

@@ -71,6 +71,7 @@ def get_frontend_configuration(request):
             "force_wss_protocol": settings.LIVEKIT_FORCE_WSS_PROTOCOL,
             "enable_firefox_proxy_workaround": settings.LIVEKIT_ENABLE_FIREFOX_PROXY_WORKAROUND,
             "default_sources": settings.LIVEKIT_DEFAULT_SOURCES,
+            "default_video_codec": settings.LIVEKIT_DEFAULT_VIDEO_CODEC,
         },
         "authenticated_users_can_edit_display_name": (
             settings.AUTHENTICATED_PARTICIPANTS_CAN_EDIT_DISPLAY_NAME

src/backend/core/tests/test_settings_video_codec.py

@@ -0,0 +1,22 @@
+"""Unit tests for the LIVEKIT_DEFAULT_VIDEO_CODEC setting value."""
+
+import pytest
+
+from meet.settings import VideoCodecValue
+
+
+@pytest.mark.parametrize(
+    "raw,expected",
+    [("vp9", "vp9"), ("AV1", "av1"), ("  h264  ", "h264")],
+)
+def test_video_codec_value_normalizes(raw, expected):
+    """Whitespace is trimmed and the name is lowercased before it is checked."""
+    # environ=False keeps __new__ from resolving the value, so the instance survives.
+    assert VideoCodecValue(environ=False).to_python(raw) == expected
+
+
+@pytest.mark.parametrize("raw", ["vp10", "", "h.264"])
+def test_video_codec_value_rejects_unsupported(raw):
+    """A name outside the accepted list stops the settings module loading."""
+    with pytest.raises(ValueError, match="Unsupported video codec"):
+        VideoCodecValue(environ=False).to_python(raw)

src/backend/meet/settings.py

@@ -53,6 +53,26 @@ def get_release():
         return "NA"  # Default: not available
 
 
+class VideoCodecValue(values.Value):
+    """
+    A video codec name, normalized to lowercase and validated against the codecs
+    supported by the LiveKit client, so that a typo fails at startup instead of
+    silently downgrading every publisher to another codec.
+    """
+
+    codecs = frozenset(("vp8", "h264", "vp9", "av1"))
+
+    def to_python(self, value):
+        """Normalize the codec name and ensure it is a supported one."""
+        codec = super().to_python(value).strip().lower()
+        if codec not in self.codecs:
+            raise ValueError(
+                f"Unsupported video codec {value!r}, "
+                f"expected one of: {', '.join(sorted(self.codecs))}."
+            )
+        return codec
+
+
 class Base(Configuration):
     """
     This is the base configuration every configuration (aka environment) should inherit from. It
@@ -678,6 +698,9 @@ class Base(Configuration):
         environ_prefix=None,
         default=False,
     )
+    LIVEKIT_DEFAULT_VIDEO_CODEC = VideoCodecValue(
+        "vp9", environ_name="LIVEKIT_DEFAULT_VIDEO_CODEC", environ_prefix=None
+    )
     CONNECTION_TEST_ENABLED = values.BooleanValue(
         environ_name="CONNECTION_TEST_ENABLED",
         environ_prefix=None,

src/frontend/src/api/useConfig.ts

@@ -3,7 +3,7 @@ import { keys } from './queryKeys'
 import { useQuery } from '@tanstack/react-query'
 import { RecordingMode } from '@/features/recording'
 import type { ApiAccessLevel } from '@/features/rooms/api/ApiRoom'
-import type { Track } from 'livekit-client'
+import type { Track, VideoCodec } from 'livekit-client'
 type Source = Track.Source
 
 export interface ApiConfig {
@@ -62,6 +62,7 @@ export interface ApiConfig {
     force_wss_protocol: boolean
     enable_firefox_proxy_workaround: boolean
     default_sources: Source[]
+    default_video_codec: VideoCodec
   }
   transcription_destination?: string
   max_participants_for_sound: number

src/frontend/src/features/rooms/components/Conference.tsx

@@ -107,7 +107,7 @@ export const Conference = ({
       adaptiveStream: true,
       dynacast: true,
       publishDefaults: {
-        videoCodec: 'vp9',
+        videoCodec: apiConfig?.livekit.default_video_codec ?? 'vp9',
       },
       videoCaptureDefaults: {
         deviceId: userConfig.videoDeviceId ?? undefined,
@@ -129,6 +129,7 @@ export const Conference = ({
     userConfig.videoPublishResolution,
     userConfig.audioDeviceId,
     userConfig.audioOutputDeviceId,
+    apiConfig?.livekit.default_video_codec,
   ])
 
   const room = useMemo(() => new Room(roomOptions), [roomOptions])

src/helm/env.d/common.yaml.gotmpl

@@ -150,6 +150,7 @@ backend:
     # Frontend
     LIVEKIT_FORCE_WSS_PROTOCOL: True
     LIVEKIT_ENABLE_FIREFOX_PROXY_WORKAROUND: True
+    LIVEKIT_DEFAULT_VIDEO_CODEC: vp9
     FRONTEND_IDLE_DISCONNECT_WARNING_DELAY: 9000
     FRONTEND_SILENCE_LIVEKIT_DEBUG: False
     FRONTEND_SUPPORT: "{'id': '58ea6697-8eba-4492-bc59-ad6562585041', 'help_article_transcript': 'https://lasuite.crisp.help/fr/article/visio-transcript-1sjq43x', 'help_article_recording': 'https://lasuite.crisp.help/fr/article/visio-enregistrement-wgc8o0', 'help_article_more_tools': 'https://lasuite.crisp.help/fr/article/visio-tools-bvxj23'}"