feat(modality)!: SnapOtter 2.0 phase 3 modality framework: media/doc engines, pool routing, display modes (#218)

2026-08-03 07:46:42 +02:00 · 2026-06-13 10:18:39 +08:00
parent c451b939c7
commit d647d8ed19
99 changed files with 4380 additions and 1813 deletions
@@ -0,0 +1,63 @@
+import { randomUUID } from "node:crypto";
+import { mkdir, rm, writeFile } from "node:fs/promises";
+import { join } from "node:path";
+import { probeMedia } from "@snapotter/media-engine";
+import { env } from "../config.js";
+import { type InputHandler, InputValidationError, type PreparedInput } from "./contract.js";
+
+/**
+ * Video/audio validation via capped ffprobe (spec 4.7). ffprobe needs a real
+ * file (mp4 moov atoms may trail), so the buffer lands in the scratch dir.
+ */
+export class MediaInputHandler implements InputHandler {
+  constructor(private kind: "video" | "audio") {}
+
+  async prepare(
+    raw: Buffer,
+    filename: string,
+    opts: { scratchDir: string },
+  ): Promise<PreparedInput> {
+    const probeDir = join(opts.scratchDir, `probe-${randomUUID()}`);
+    await mkdir(probeDir, { recursive: true });
+    const probePath = join(probeDir, "input");
+    try {
+      await writeFile(probePath, raw);
+      let info: Awaited<ReturnType<typeof probeMedia>>;
+      try {
+        info = await probeMedia(probePath);
+      } catch (err) {
+        throw new InputValidationError(
+          `Unrecognized ${this.kind} file: ${err instanceof Error ? err.message : String(err)}`,
+        );
+      }
+      const hasVideo = info.streams.some((s) => s.type === "video");
+      const hasAudio = info.streams.some((s) => s.type === "audio");
+      if (this.kind === "video" && !hasVideo) {
+        throw new InputValidationError("File contains no video stream");
+      }
+      if (this.kind === "audio" && !hasAudio) {
+        throw new InputValidationError("File contains no audio stream");
+      }
+      const durationCap =
+        this.kind === "video" ? env.MAX_VIDEO_DURATION_S : env.MAX_AUDIO_DURATION_S;
+      if (durationCap > 0 && info.durationS !== null && info.durationS > durationCap) {
+        throw new InputValidationError(
+          `Duration ${Math.round(info.durationS)}s exceeds the maximum of ${durationCap}s`,
+        );
+      }
+      if (
+        this.kind === "video" &&
+        env.MAX_VIDEO_BITRATE_KBPS > 0 &&
+        info.bitrateKbps !== null &&
+        info.bitrateKbps > env.MAX_VIDEO_BITRATE_KBPS
+      ) {
+        throw new InputValidationError(
+          `Bitrate ${info.bitrateKbps}kbps exceeds the maximum of ${env.MAX_VIDEO_BITRATE_KBPS}kbps`,
+        );
+      }
+      return { buffer: raw, filename };
+    } finally {
+      await rm(probeDir, { recursive: true, force: true }).catch(() => {});
+    }
+  }
+}