test(producer): add stream duration parity check to regression harness (#1652)

Probes the rendered output for video and audio stream durations after render and fails the test if they differ by more than 0.5s. Catches mux-level truncation regressions like the ffmpeg -shortest bug (#1648) where one stream gets silently cut short. Runs on all non-png-sequence fixtures with audio — no new meta.json field needed since this is a universal invariant, not a per-fixture threshold.
2026-09-12 07:09:59 +00:00 · 2026-06-22 18:32:59 -04:00
parent 4976b5e036
commit 60d3eeb1f7
9 changed files with 383 additions and 3 deletions
@@ -0,0 +1,157 @@
+import { mkdtempSync, rmSync } from "node:fs";
+import { execFileSync } from "node:child_process";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { afterEach, describe, expect, it } from "vitest";
+import { getFfmpegBinary } from "@hyperframes/engine";
+import { checkStreamDurationParity, MAX_STREAM_DRIFT_SECONDS } from "../regression-harness.js";
+
+const tempDirs: string[] = [];
+
+afterEach(() => {
+  for (const dir of tempDirs.splice(0)) {
+    rmSync(dir, { recursive: true, force: true });
+  }
+});
+
+function mktmp(): string {
+  const dir = mkdtempSync(join(tmpdir(), "hf-parity-"));
+  tempDirs.push(dir);
+  return dir;
+}
+
+function ffmpeg(args: string[]): void {
+  execFileSync(getFfmpegBinary(), ["-y", "-hide_banner", "-loglevel", "error", ...args], {
+    timeout: 30_000,
+  });
+}
+
+function muxWithMatchingDurations(dir: string): string {
+  const out = join(dir, "matched.mp4");
+  const video = join(dir, "v.mp4");
+  const audio = join(dir, "a.aac");
+  ffmpeg([
+    "-f",
+    "lavfi",
+    "-i",
+    "color=c=blue:s=64x64:d=5:r=30",
+    "-c:v",
+    "libx264",
+    "-preset",
+    "ultrafast",
+    "-pix_fmt",
+    "yuv420p",
+    video,
+  ]);
+  ffmpeg([
+    "-f",
+    "lavfi",
+    "-i",
+    "sine=frequency=440:duration=5",
+    "-c:a",
+    "aac",
+    "-b:a",
+    "64k",
+    audio,
+  ]);
+  ffmpeg([
+    "-i",
+    video,
+    "-i",
+    audio,
+    "-c:v",
+    "copy",
+    "-c:a",
+    "copy",
+    "-movflags",
+    "+faststart",
+    out,
+  ]);
+  return out;
+}
+
+function muxWithTruncatedVideo(dir: string): string {
+  const out = join(dir, "truncated.mp4");
+  const video = join(dir, "v-short.mp4");
+  const audio = join(dir, "a-long.aac");
+  ffmpeg([
+    "-f",
+    "lavfi",
+    "-i",
+    "color=c=red:s=64x64:d=2:r=30",
+    "-c:v",
+    "libx264",
+    "-preset",
+    "ultrafast",
+    "-pix_fmt",
+    "yuv420p",
+    video,
+  ]);
+  ffmpeg([
+    "-f",
+    "lavfi",
+    "-i",
+    "sine=frequency=440:duration=10",
+    "-c:a",
+    "aac",
+    "-b:a",
+    "64k",
+    audio,
+  ]);
+  ffmpeg([
+    "-i",
+    video,
+    "-i",
+    audio,
+    "-c:v",
+    "copy",
+    "-c:a",
+    "copy",
+    "-movflags",
+    "+faststart",
+    out,
+  ]);
+  return out;
+}
+
+describe("checkStreamDurationParity", () => {
+  it("passes when video and audio durations match", async () => {
+    const dir = mktmp();
+    const video = muxWithMatchingDurations(dir);
+    const result = await checkStreamDurationParity(video);
+    expect(result).not.toBeNull();
+    expect(result!.passed).toBe(true);
+    expect(result!.driftSeconds).toBeLessThanOrEqual(MAX_STREAM_DRIFT_SECONDS);
+  });
+
+  it("fails when video is truncated relative to audio (regression #1648)", async () => {
+    const dir = mktmp();
+    const video = muxWithTruncatedVideo(dir);
+    const result = await checkStreamDurationParity(video);
+    expect(result).not.toBeNull();
+    expect(result!.passed).toBe(false);
+    expect(result!.videoDurationSeconds).toBeLessThan(3);
+    expect(result!.audioDurationSeconds).toBeGreaterThan(9);
+    expect(result!.driftSeconds).toBeGreaterThan(MAX_STREAM_DRIFT_SECONDS);
+  });
+
+  it("returns null for video-only files (no audio stream)", async () => {
+    const dir = mktmp();
+    const video = join(dir, "silent.mp4");
+    ffmpeg([
+      "-f",
+      "lavfi",
+      "-i",
+      "color=c=green:s=64x64:d=3:r=30",
+      "-c:v",
+      "libx264",
+      "-preset",
+      "ultrafast",
+      "-pix_fmt",
+      "yuv420p",
+      video,
+    ]);
+    const result = await checkStreamDurationParity(video);
+    expect(result).toBeNull();
+  });
+});