video.js

const express = require("express");
const ytdl = require("ytdl-core");
const ffmpegPath = require("ffmpeg-static");
const spawn = require("child_process").spawn;
const fs = require("fs");
const app = express();
const port = 3000;

const startMinute = 3;
const startSecond = 51;
const endMinute = 4;
const endSecond = 51;

app.use(express.json());

app.post("/download-cut-and-merge", async (req, res) => {
  try {
    const { videoUrl } = req.body;

    if (!videoUrl) {
      return res.status(400).json({ error: "url not provided" });
    }

    const videoFileName = `${Date.now()}_video.mp4`;
    const audioFileName = `${Date.now()}_audio.aac`;
    const finalFileName = `${Date.now()}_final.mp4`;

    const start = startMinute * 60 + startSecond;
    const end = endMinute * 60 + endSecond;

    const videoStream = ytdl(videoUrl, {
      filter: (format) => {
        return (
          (format.container === "mp4" &&
            format.hasVideo &&
            format.quality === "hd2160") ||
          (format.container === "webm" &&
            format.hasVideo &&
            format.quality === "hd2160")
        );
      },
      range: { start: 0, end: 1000 }
    });

    videoStream.pipe(fs.createWriteStream(videoFileName));

    videoStream.on("end", () => {
      const audioStream = ytdl(videoUrl, {
        format: "audioonly"
      });

      audioStream.pipe(fs.createWriteStream(audioFileName));

      audioStream.on("end", () => {
        const ffmpegProcess = spawn(ffmpegPath, [
          "-i",
          videoFileName,
          "-i",
          audioFileName,
          "-c:v",
          "libx264",
          "-c:a",
          "aac",
          finalFileName
        ]);

        ffmpegProcess.on("close", () => {
          const outputPath = `./downloads/${finalFileName}`;
          fs.unlinkSync(videoFileName);
          fs.unlinkSync(audioFileName);

          const checkInterval = setInterval(() => {
            if (fs.existsSync(outputPath)) {
              clearInterval(checkInterval);
              res.download(outputPath, "final_video.mp4", (err) => {
                if (err) {
                  console.error("error:", err);
                  res.status(500).json({ error: "error" });
                }
              });
            }
          }, 1000);
        });

        ffmpegProcess.on("error", (err) => {
          console.error("ffmpeg error:", err);
          res.status(500).json({ error: "ffmpeg error" });
        });
      });

      audioStream.on("error", (err) => {
        console.error("audio error:", err);
        res.status(500).json({ error: "audio error" });
      });
    });

    videoStream.on("error", (err) => {
      console.error("error to download video:", err);
      res.status(500).json({ error: "error to download video" });
    });
  } catch (err) {
    console.error("idk:", err);
    res.status(500).json({ error: "idk" });
  }
});

app.listen(port, () => {
  console.log(`running at port ${port}`);
});