test: use supported FFmpeg flags for VFR fixtures (#5352)

packages/engine/src/services/videoFrameExtractor.test.ts

@@ -2362,7 +2362,7 @@ describe.skipIf(!HAS_FFMPEG)("held tails on sparse-timestamp sources", () => {
       {
         path: vfrFixture,
         input: "testsrc2=s=64x64:d=10:rate=1/2",
-        filters: ["-vf", "select='eq(n,0)+eq(n,2)'", "-vsync", "vfr"],
+        filters: ["-vf", "select='eq(n,0)+eq(n,2)'", "-fps_mode", "vfr"],
       },
       {
         path: nonZeroStartFixture,
@@ -2534,7 +2534,7 @@ describe.skipIf(!HAS_FFMPEG)("extractAllVideoFrames on a VFR source", () => {
 
   beforeAll(async () => {
     // 10s testsrc2 at 60fps, ~40% of frames dropped via select filter and
-    // encoded with -vsync vfr so timestamps are irregular. Declared fps 60,
+    // encoded with -fps_mode vfr so timestamps are irregular. Declared fps 60,
     // actual average ~36 — well over the 10% threshold used by isVFR.
     // The select expression drops four 1-second windows (frames 30-89,
     // 180-239, 330-389, 480-539) to simulate static segments in a screen
@@ -2552,7 +2552,7 @@ describe.skipIf(!HAS_FFMPEG)("extractAllVideoFrames on a VFR source", () => {
       "testsrc2=s=320x180:d=10:rate=60",
       "-vf",
       "select='not(between(n\\,30\\,89))*not(between(n\\,180\\,239))*not(between(n\\,330\\,389))*not(between(n\\,480\\,539))'",
-      "-vsync",
+      "-fps_mode",
       "vfr",
       "-c:v",
       "libx264",

packages/producer/src/services/render/stages/captureHdrResources.test.ts

@@ -335,7 +335,7 @@ describe.skipIf(!HAS_FFMPEG)("raw HDR held tails on sparse-timestamp sources", (
       {
         path: vfrFixture,
         input: "testsrc2=s=64x64:d=10:rate=1/2",
-        filters: ["-vf", "select='eq(n,0)+eq(n,2)'", "-vsync", "vfr"],
+        filters: ["-vf", "select='eq(n,0)+eq(n,2)'", "-fps_mode", "vfr"],
       },
       {
         path: nonZeroStartFixture,