enhance(server): videoThumbnailGenerator config (#9845)

* enhance(server): videoThumbnailGenerator config

* ✌️

* fix

* 相対url

* サムネイルのproxyRemoteFilesは直接プロキシを指定する

* メディアプロキシ

packages/backend/src/config.ts

@@ -67,6 +67,7 @@ export type Source = {
 
 	mediaProxy?: string;
 	proxyRemoteFiles?: boolean;
+	videoThumbnailGenerator?: string;
 
 	signToActivityPubGet?: boolean;
 };
@@ -89,6 +90,7 @@ export type Mixin = {
 	clientManifestExists: boolean;
 	mediaProxy: string;
 	externalMediaProxyEnabled: boolean;
+	videoThumbnailGenerator: string | null;
 };
 
 export type Config = Source & Mixin;
@@ -144,6 +146,10 @@ export function loadConfig() {
 	mixin.mediaProxy = externalMediaProxy ?? internalMediaProxy;
 	mixin.externalMediaProxyEnabled = externalMediaProxy !== null && externalMediaProxy !== internalMediaProxy;
 
+	mixin.videoThumbnailGenerator = config.videoThumbnailGenerator ?
+		config.videoThumbnailGenerator.endsWith('/') ? config.videoThumbnailGenerator.substring(0, config.videoThumbnailGenerator.length - 1) : config.videoThumbnailGenerator
+		: null;
+
 	if (!config.redis.prefix) config.redis.prefix = mixin.host;
 
 	return Object.assign(config, mixin);