> ## Documentation Index
> Fetch the complete documentation index at: https://rendi.dev/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Build a video from images and audio (slideshow)

> Combine images and an audio track into a video using Rendi's FFmpeg API. Node.js, Python, and cURL examples.

Combine a set of images and an audio track into a single video. Each image displays for a fixed duration and the audio plays over the top — finishing when the audio ends.

## Code

<Tabs>
  <Tab title="Node.js">
    ```js theme={null}
    const API_KEY = process.env.RENDI_API_KEY;

    const submit = await fetch("https://api.rendi.dev/v1/run-ffmpeg-command", {
      method: "POST",
      headers: {
        "Content-Type": "application/json",
        "X-API-KEY": API_KEY,
      },
      body: JSON.stringify({
        input_files: {
          in_img_1: "https://storage.rendi.dev/sample/bbb-splash.png",
          in_img_2: "https://storage.rendi.dev/sample/rodents.png",
          in_img_3: "https://storage.rendi.dev/sample/evil-frank.png",
          in_audio_1: "https://storage.rendi.dev/sample/Neon%20Lights.mp3",
        },
        output_files: {
          out_1: "slideshow.mp4",
        },
        ffmpeg_command:
          '-loop 1 -t 5 -i {{in_img_1}} -loop 1 -t 5 -i {{in_img_2}} -loop 1 -t 5 -i {{in_img_3}} -i {{in_audio_1}} -filter_complex "[0:v][1:v][2:v]concat=n=3:v=1:a=0,format=yuv420p[v]" -map [v] -map 3:a -c:v libx264 -c:a aac -shortest {{out_1}}',
      }),
    });
    const { command_id } = await submit.json();

    while (true) {
      const res = await fetch(`https://api.rendi.dev/v1/commands/${command_id}`, {
        headers: { "X-API-KEY": API_KEY },
      });
      const data = await res.json();
      if (data.status === "SUCCESS") {
        console.log("Slideshow URL:", data.output_files.out_1.storage_url);
        break;
      }
      if (data.status === "FAILED") throw new Error("Command failed");
      await new Promise((r) => setTimeout(r, 2000));
    }
    ```
  </Tab>

  <Tab title="Python">
    ```python theme={null}
    import os
    import time
    import requests

    API_KEY = os.environ["RENDI_API_KEY"]
    BASE = "https://api.rendi.dev/v1"
    headers = {"X-API-KEY": API_KEY}

    submit = requests.post(
        f"{BASE}/run-ffmpeg-command",
        headers=headers,
        json={
            "input_files": {
                "in_img_1": "https://storage.rendi.dev/sample/bbb-splash.png",
                "in_img_2": "https://storage.rendi.dev/sample/rodents.png",
                "in_img_3": "https://storage.rendi.dev/sample/evil-frank.png",
                "in_audio_1": "https://storage.rendi.dev/sample/Neon%20Lights.mp3",
            },
            "output_files": {"out_1": "slideshow.mp4"},
            "ffmpeg_command": '-loop 1 -t 5 -i {{in_img_1}} -loop 1 -t 5 -i {{in_img_2}} -loop 1 -t 5 -i {{in_img_3}} -i {{in_audio_1}} -filter_complex "[0:v][1:v][2:v]concat=n=3:v=1:a=0,format=yuv420p[v]" -map [v] -map 3:a -c:v libx264 -c:a aac -shortest {{out_1}}',
        },
    )
    command_id = submit.json()["command_id"]

    while True:
        res = requests.get(f"{BASE}/commands/{command_id}", headers=headers).json()
        if res["status"] == "SUCCESS":
            print("Slideshow URL:", res["output_files"]["out_1"]["storage_url"])
            break
        if res["status"] == "FAILED":
            raise RuntimeError("Command failed")
        time.sleep(2)
    ```
  </Tab>

  <Tab title="cURL">
    ```bash theme={null}
    curl --request POST \
      --url https://api.rendi.dev/v1/run-ffmpeg-command \
      --header 'Content-Type: application/json' \
      --header 'X-API-KEY: <api-key>' \
      --data '{
        "input_files": {
          "in_img_1": "https://storage.rendi.dev/sample/bbb-splash.png",
          "in_img_2": "https://storage.rendi.dev/sample/rodents.png",
          "in_img_3": "https://storage.rendi.dev/sample/evil-frank.png",
          "in_audio_1": "https://storage.rendi.dev/sample/Neon%20Lights.mp3"
        },
        "output_files": {"out_1": "slideshow.mp4"},
        "ffmpeg_command": "-loop 1 -t 5 -i {{in_img_1}} -loop 1 -t 5 -i {{in_img_2}} -loop 1 -t 5 -i {{in_img_3}} -i {{in_audio_1}} -filter_complex \"[0:v][1:v][2:v]concat=n=3:v=1:a=0,format=yuv420p[v]\" -map [v] -map 3:a -c:v libx264 -c:a aac -shortest {{out_1}}"
      }'

    curl --request GET \
      --url https://api.rendi.dev/v1/commands/<command_id> \
      --header 'X-API-KEY: <api-key>'
    ```
  </Tab>
</Tabs>

## How the FFmpeg command works

* `-loop 1 -t 5 -i {{in_img_1}}` — loop each image for 5 seconds (repeat per image)
* `-i {{in_audio_1}}` — audio track as the last input
* `concat=n=3:v=1:a=0` — concatenate the 3 video streams, 1 video, 0 audio
* `format=yuv420p` — pixel format compatible with most players
* `-map [v] -map 3:a` — pick the concatenated video + audio from input index 3
* `-shortest` — stop when the shortest stream ends (typically when video runs out)
* `{{out_1}}` — output file

For longer images, increase `-t 5` per input. For crossfades between images, replace `concat` with `xfade`.

## Response

```json theme={null}
{
  "output_files": {
    "out_1": {
      "file_id": "10cfed0c-...",
      "size_mbytes": 1.09,
      "duration": 15.001,
      "file_type": "video",
      "file_format": "mp4",
      "storage_url": "https://storage.rendi.dev/temp_files/.../slideshow.mp4",
      "width": 1920,
      "height": 1080,
      "codec": "h264",
      "frame_rate": 25.0,
      "bitrate_video_kb": 453.5,
      "bitrate_audio_kb": 132.6
    }
  },
  "status": "SUCCESS",
  "command_type": "FFMPEG_COMMAND"
}
```

## Related

* [Merge videos](/examples/merge-videos)
* [Overlay watermark](/examples/overlay-watermark)
* [Cheatsheet — Image to video](https://github.com/rendi-api/ffmpeg-cheatsheet#image-to-video)