Guides · Convert video to MP4

# Convert video to MP4

Send the video as an input and name an `.mp4` output with H.264 video and AAC audio. The response holds a download URL for the MP4, the job’s usage and its price.

## The request

Request

```bash
curl https://media.logicboostkit.com/ffmpeg/process \
  -H "Authorization: Basic $MEDIA_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "task": {
      "inputs": [
        {
          "file_path": "dir_pi23jgy1yxlmigi873bz/source.mov"
        }
      ],
      "outputs": [
        {
          "file": "video.mp4",
          "options": [
            "-c:v",
            "libx264",
            "-preset",
            "medium",
            "-crf",
            "23",
            "-c:a",
            "aac",
            "-b:a",
            "128k",
            "-movflags",
            "+faststart"
          ]
        }
      ]
    }
  }'
```

Response

```http
HTTP/1.1 200 OK
X-Request-Id: job_0mv6hqvpqkiwproi518azpod

{
  "ok": true,
  "result": [
    {
      "file_name": "video.mp4",
      "size_bytes": 98566144,
      "download_url": "https://…"
    }
  ],
  "usage": {
    "time_sec": 38.4,
    "input_size_gb": 0.384,
    "output_size_gb": 0.091796875,
    "gb_sec": 18.270599985
  },
  "request_id": "job_0mv6hqvpqkiwproi518azpod",
  "amount_usd": 0.243364392
}
```

The input is a file you uploaded ([POST /file](https://media.logicboostkit.com/docs/post-file)). The full reference is [POST /ffmpeg/process](https://media.logicboostkit.com/docs/post-ffmpeg-process).

## The options, explained

What each option does

- `-c:v libx264`: Encode the video as H.264, which every browser and device plays.
- `-preset medium`: The balance of encoding speed and file size. Slower presets make smaller files and take longer.
- `-crf 23`: Constant quality. Lower is better quality and a bigger file; 18 looks close to the source, 28 is visibly softer.
- `-c:a aac -b:a 128k`: AAC audio at 128 kbit/s.
- `-movflags +faststart`: Puts the MP4’s index at the start of the file, so playback can begin before the download ends.

## Variations

### Keep the streams as they are

If the source is already H.264 and AAC, change only the container. It takes seconds.

```
In the output: "options": ["-c", "copy", "-movflags", "+faststart"]
```

### H.265 for smaller files

About half the size of H.264 at the same quality. Not every browser plays it.

```
In the output: "options": ["-c:v", "libx265", "-crf", "28", "-tag:v", "hvc1", "-c:a", "aac"]
```

### From a URL

Give the input’s `file_path` as a public HTTPS URL to skip the upload.

## What it costs

A 1 GB recording that becomes a 0.25 GB MP4 in 95 seconds: (1 GB + 0.25 GB) × 95 s = 118.750 GB-seconds, which is USD 1.5818 at USD 0.01332 per GB-second.

The seconds are an example; every response reports the job’s own. Failed jobs are not charged. See [Pricing](https://media.logicboostkit.com/pricing).