Fit Studio 2 inputs and report live generation progress

server/utils/studio2/media.ts

@@ -0,0 +1,13 @@
+import { mkdtempSync, writeFileSync, readFileSync, rmSync } from 'node:fs'
+import { join } from 'node:path'
+import { tmpdir } from 'node:os'
+import { runFfmpeg } from '../ffmpeg'
+export async function fitStill(data: Buffer, width: number, height: number) {
+  const dir=mkdtempSync(join(tmpdir(),'studio2-fit-'))
+  try {
+    const input=join(dir,'source'),output=join(dir,'fitted.png')
+    writeFileSync(input,data)
+    await runFfmpeg(['-y','-i',input,'-vf',`scale=${width}:${height}:force_original_aspect_ratio=decrease,pad=${width}:${height}:(ow-iw)/2:(oh-ih)/2:color=black,setsar=1`,'-frames:v','1',output])
+    return readFileSync(output)
+  } finally { rmSync(dir,{recursive:true,force:true}) }
+}