Preserve extension quality with original segments and reliable refinement

server/utils/videoSources.ts

@@ -0,0 +1,23 @@
+import { existsSync, mkdirSync, readdirSync, linkSync, copyFileSync, writeFileSync } from 'node:fs'
+import { dirname, join } from 'node:path'
+
+/** Each saved clip owns its sources, so deleting a parent cannot break extensions. */
+export function videoSourcePaths(videoPath: string) {
+  const dir = join(dirname(videoPath), 'sources')
+  if (existsSync(dir)) {
+    const paths = readdirSync(dir).filter(name => /^\d{6}\.mp4$/.test(name)).sort().map(name => join(dir, name))
+    if (paths.length) return paths
+  }
+  // Legacy clips become a fixed baseline; their past compression is irreversible.
+  return [videoPath]
+}
+
+export function preserveVideoSources(videoPath: string, parents: string[], segment: Buffer) {
+  const dir = join(dirname(videoPath), 'sources')
+  mkdirSync(dir, { recursive: true })
+  parents.forEach((source, index) => {
+    const dest = join(dir, `${String(index).padStart(6, '0')}.mp4`)
+    try { linkSync(source, dest) } catch { copyFileSync(source, dest) }
+  })
+  writeFileSync(join(dir, `${String(parents.length).padStart(6, '0')}.mp4`), segment)
+}