Export

Re-encode video with quality presets, custom codec settings, and hardware acceleration.

Quick example

import { ffmpeg } from "ffmpeg-kit";

await ffmpeg.exportVideo()
  .input("raw.mp4")
  .preset("youtube_1080p")
  .faststart()
  .output("youtube.mp4")
  .execute();

API

.input(path) / .videoInput(path) / .audioInput(path)

Method	Description
.input(path)	Single input file (video + audio)
.videoInput(path)	Video-only input (use with .audioInput())
.audioInput(path)	Audio-only input (use with .videoInput())

.preset(name)

Apply a delivery preset. See Presets for the full list.

.preset("youtube_1080p")
.preset("web_h264")
.preset("instagram_story")

.videoCodec(codec)

Common values	Description
"h264"	H.264 / AVC
"h265" / "hevc"	H.265 / HEVC
"av1"	AV1
"vp9"	VP9
"copy"	Copy stream without re-encoding

.audioCodec(codec)

Common values	Description
"aac"	AAC (default for MP4)
"mp3"	MP3
"opus"	Opus (great for WebM)
"copy"	Copy stream without re-encoding

.crf(value)

Constant Rate Factor — quality-based encoding. Lower = better quality / larger file.

Value	Quality
18	Near-lossless
20–23	High quality (recommended)
28	Good quality, smaller file
35+	Low quality

.videoBitrate(bitrate) / .audioBitrate(bitrate)

Bitrate strings: "4M", "2000k", "192k".

.pixelFormat(fmt)

Usually "yuv420p" for maximum compatibility.

.faststart()

Move MP4 metadata to the start of the file for web streaming (moov atom at front). Equivalent to -movflags +faststart.

.hwAccel(mode)

Mode	Description
"auto"	Try GPU, fall back to CPU
"nvidia"	Force NVENC
"vaapi"	Force VAAPI
"qsv"	Force Intel QSV
"cpu"	Software encoding

.output(path)

Output file path. Required.

Examples

YouTube upload

await ffmpeg.exportVideo()
  .input("raw.mp4")
  .preset("youtube_1080p")
  .faststart()
  .hwAccel("auto")
  .output("youtube.mp4")
  .execute();

Custom encoding with separate audio

await ffmpeg.exportVideo()
  .videoInput("video-only.mp4")
  .audioInput("audio.wav")
  .videoCodec("h264")
  .crf(20)
  .audioBitrate("192k")
  .pixelFormat("yuv420p")
  .faststart()
  .output("final.mp4")
  .execute();

Copy streams (fast remux)

await ffmpeg.exportVideo()
  .input("input.mkv")
  .videoCodec("copy")
  .audioCodec("copy")
  .output("output.mp4")
  .execute();

Result type

interface ExportResult {
  outputPath: string;
  width: number;
  height: number;
  duration: number;
  size: number;
  videoCodec: string;
  audioCodec: string;
  probeResult: ProbeResult;
}

Related

• Presets — full preset listing
• Hardware Acceleration — GPU encoding guide
• Smart Transcode — probe-first, skip if already correct codec