TypeScript API#

Import the wrapper APIs from the package root:

import { execFfmpeg, execFfprobe, runFfmpeg, runFfprobe } from "@steipete/ffmpeg-wasm-local";

Buffered Runs#

Use runFfmpeg and runFfprobe when stdout and stderr should be buffered.

const probe = await runFfprobe([
  "-v",
  "error",
  "-show_entries",
  "format=duration",
  "-of",
  "default=noprint_wrappers=1:nokey=1",
  "input.mp4",
]);

if (probe.exitCode !== 0) {
  throw new Error(probe.stderrText);
}

The result includes stdout, stderr, stdoutText, stderrText, and exitCode.

Streaming Runs#

Use execFfmpeg and execFfprobe for CLI-like execution.

const result = await execFfmpeg([
  "-hide_banner",
  "-i",
  "input.mp4",
  "-vn",
  "-ac",
  "1",
  "-ar",
  "16000",
  "audio.wav",
]);

if (result.exitCode !== 0) {
  throw new Error("ffmpeg failed");
}

Options#

All APIs accept:

• distDir for a custom wasm asset directory.
• cwd and env for process isolation.
• stdin for pipe input.
• stdinMode for binary or text input.
• timeoutMs for bounded work.

FFmpeg receives -nostdin automatically unless the caller already supplies it. Explicit -i - pipe workflows still work.