Initial commit: PodcastYes — AI podcast platform

2026-06-07 03:58:32 -04:00
commit 155507f21a
151 changed files with 19826 additions and 0 deletions
@@ -0,0 +1,60 @@
+import { promises as fs } from "node:fs";
+import os from "node:os";
+import path from "node:path";
+import { runFfmpeg, ffprobeDuration } from "../ffmpeg";
+
+/**
+ * Concatenate per-segment MP3 buffers into one normalized episode MP3.
+ *
+ * Segments are re-encoded (not stream-copied) through a single libmp3lame pass
+ * with loudness normalization, which guarantees a uniform codec/bitrate and
+ * avoids the header/timestamp glitches that `-c copy` concat can produce.
+ */
+export async function stitchMp3(
+  segments: Buffer[]
+): Promise<{ data: Buffer; durationSec: number | null }> {
+  if (segments.length === 0) throw new Error("No audio segments to stitch");
+
+  const dir = await fs.mkdtemp(path.join(os.tmpdir(), "podcastyes-"));
+  try {
+    const files: string[] = [];
+    for (let i = 0; i < segments.length; i++) {
+      const file = path.join(dir, `seg_${String(i).padStart(4, "0")}.mp3`);
+      await fs.writeFile(file, segments[i]);
+      files.push(file);
+    }
+
+    // concat demuxer list — forward slashes so it parses on Windows and Linux.
+    const listPath = path.join(dir, "list.txt");
+    const listBody = files
+      .map((f) => `file '${f.split(path.sep).join("/").replace(/'/g, "'\\''")}'`)
+      .join("\n");
+    await fs.writeFile(listPath, listBody);
+
+    const outPath = path.join(dir, "episode.mp3");
+    await runFfmpeg([
+      "-y",
+      "-f",
+      "concat",
+      "-safe",
+      "0",
+      "-i",
+      listPath,
+      "-af",
+      "loudnorm=I=-16:TP=-1.5:LRA=11",
+      "-c:a",
+      "libmp3lame",
+      "-b:a",
+      "128k",
+      "-ar",
+      "44100",
+      outPath,
+    ]);
+
+    const data = await fs.readFile(outPath);
+    const durationSec = await ffprobeDuration(outPath);
+    return { data, durationSec };
+  } finally {
+    await fs.rm(dir, { recursive: true, force: true }).catch(() => {});
+  }
+}