ffmpeg-kit

Appearance

Pipeline ​

The pipeline builder chains multiple operations with automatic temp file management. Each step receives its dependencies and produces output that the next step can use.

Basic usage ​

typescript
import { ffmpeg, transform, exportVideo } from "ffmpeg-kit";

const result = await ffmpeg.pipeline()
  .step("scale", (deps) =>
    transform(deps).input("input.mp4").scale({ width: 1280 }).output("$tmp"))
  .step("export", (deps) =>
    exportVideo(deps).input("$prev").preset("youtube_1080p").output("output.mp4"))
  .execute();

$tmp and $prev placeholders ​

  • $tmp — allocates a temporary file. Auto-cleaned after the pipeline completes.
  • $prev — refers to the output of the previous step.
typescript
await ffmpeg.pipeline()
  .step("normalize", (deps) =>
    transform(deps).input("video.mp4").scale({ width: 1920 }).output("$tmp"))
  .step("audio", (deps) =>
    audio(deps).input("$prev").normalize({ targetLUFS: -16 }).output("$tmp"))
  .step("export", (deps) =>
    exportVideo(deps).input("$prev").preset("youtube_1080p").output("final.mp4"))
  .execute();

Auto temp file cleanup ​

Temp files created by $tmp are automatically deleted after .execute() completes, whether it succeeds or throws. No manual cleanup needed.

Accessing step results ​

typescript
const pipeline = await ffmpeg.pipeline()
  .step("extract", (deps) =>
    transform(deps).input("video.mp4").trimStart(10).duration(30).output("$tmp"))
  .step("export", (deps) =>
    exportVideo(deps).input("$prev").output("clip.mp4"))
  .execute();

// pipeline.results is a map of step name → result
console.log(pipeline.results.export.outputPath); // "clip.mp4"

Error handling ​

If any step fails, the pipeline throws FFmpegError (or returns { success: false } with .tryExecute()). Temp files are still cleaned up.

typescript
const result = await ffmpeg.pipeline()
  .step("scale", (deps) =>
    transform(deps).input("video.mp4").scale({ width: 1280 }).output("$tmp"))
  .step("export", (deps) =>
    exportVideo(deps).input("$prev").output("out.mp4"))
  .tryExecute();

if (!result.success) {
  console.error("Pipeline failed at step:", result.error.message);
}