Fast Forward

An easy to use ffmpeg module for Deno.

⚠️ Work In Progress! Expect breaking changes!

Installation
Usage
Getting Started
Examples
Contributing
License

Installation

This is a Deno module and can be imported directly from the repo and from following registries.

import { ffmpeg } from "https://deno.land/x/fast_forward@<version>/prompt/mod.ts";

Nest Registry

import { ffmpeg } from "https://x.nest.land/fast_forward@<version>/prompt/mod.ts";

Github

import { ffmpeg } from "https://raw.githubusercontent.com/c4spar/deno-fast-forward/<version>/prompt/mod.ts";

Usage

await ffmpeg("https://www.w3schools.com/html/mov_bbb.mp4")
  // Global encoding options (applied to all outputs).
  .audioBitrate("192k")
  .videoBitrate("1M")
  .width(480)
  .height(640)
  // Ouput 1.
  .output("output.mp4")
  .audioCodec("aac")
  .videoCodec("libx264")
  // Ouput 2.
  .output("output.webm")
  .audioCodec("libvorbis")
  .videoCodec("libvpx-vp9")
  // Start encoding.
  .encode();

console.log("All encodings done!");

$ deno run --allow-read --allow-run https://deno.land/x/fast_forward/examples/usage.ts

Getting Started

First create an instance of FFmpeg.

const encoder = ffmpeg("https://www.w3schools.com/html/mov_bbb.mp4");
// or using the constructor
const encoder = new FFmpeg("https://www.w3schools.com/html/mov_bbb.mp4");

Then you can define global options and events which will be applied to all defined outputs.

encoder
  .audioBitrate("192k")
  .videoBitrate("1M")
  .addEventListener(
    "progress",
    (event) => console.log("Progress: %s", event.progress),
  )
  .addEventListener("error", (event) => console.log(event.error));

The .output() method add’s a new encoding object which inherits all global options and events. Multiple outputs can be added with additional options for each output.

encoder
  .output("output-x264.mp4")
  .videoCodec("libx264")
  .output("output-x265.mp4")
  .videoCodec("libx265");

To start the encoding just call the .encode() method and await the returned promise.

await encoder.encode();

To get more control over the encoding precesses you can use the encoder instance as async iterator to iterate over all encoding processes with a for await loop. The process instance is an wrapper around the deno process and has almost the same methods and properties. The encoding process can be started with the .run() method and must be closed with the .close() method after the process is finished or has failed.

There are to different ways to await the status. The first one is using the .status() method, same like with the deno process.

for await (const process: EndofingProcess of encoder) {
  process.run();
  const status: EncodingStatus = await process.status();
  if (!status.success) {
    process.close();
    throw new Error("Encoding failed.");
  }
  process.close();
}
console.log("All encodings done!");

The second one is using an async iterator. You can use the encoding process as async iterator to iterate over all encoding events. If no error occurs then the status is success, if the status is not success or any encoding error occurs an error event is emitted.

for await (const process: EndofingProcess of encoder) {
  process.run();
  for await (const event: EncodingEvent of process) {
    switch (event.type) {
      case "start":
        console.log("start encoding of: %s", event.encoding.output);
        return;
      case "info":
        console.log("Media info loaded: %o", event.info);
        return;
      case "progress":
        console.log(
          "Encoding progress of: %s - %n%",
          event.encoding.output,
          event.progress,
        );
        return;
      case "end":
        console.log("Encoding of %s done!", event.encoding.output);
        return;
      case "error":
        process.close();
        throw event.error;
    }
  }
  process.close();
}
console.log("All encodings done!");

Examples

Events

await ffmpeg("https://www.w3schools.com/html/mov_bbb.mp4")
  .audioBitrate("192k")
  .videoBitrate("1M")
  .width(480)
  .height(640)
  .addEventListener("start", (event) => console.log("Event: %s", event.type))
  .addEventListener("info", (event) => console.log("Event: %s", event.type))
  .addEventListener("progress", (event) => console.log("Event: %s", event.type))
  .addEventListener("end", (event) => console.log("Event: %s", event.type))
  .addEventListener("error", (error) => console.log("Event: %s", error.type))
  .output("output.mp4")
  .output("output.webm")
  .encode();

console.log("All encodings done!");

$ deno run --allow-read --allow-run https://deno.land/x/fast_forward/examples/events.ts

Process handling

const encoder = ffmpeg("https://www.w3schools.com/html/mov_bbb.mp4")
  .audioBitrate("192k")
  .videoBitrate("1M")
  .width(480)
  .height(640)
  .output("output.mp4")
  .output("output.mkv");

for await (const process: EncodingProcess of encoder) {
  process.run();
  const status: EncodingStatus = await process.status();
  process.close();
  if (!status.success) {
    throw new Error(
      `Encoding failed: ${process.encoding.output}\n${
        new TextDecoder().decode(await process.stderrOutput())
      }`,
    );
  }
  console.log("Encoding of %s done!", process.encoding.output);
}

console.log("All encodings done!");

$ deno run --allow-read --allow-run https://deno.land/x/fast_forward/examples/process-handling.ts

Event Stream

const spinner = wait({ text: "" });

const encoder = ffmpeg("https://www.w3schools.com/html/mov_bbb.mp4")
  .audioBitrate("192k")
  .videoBitrate("1M")
  .width(480)
  .height(640)
  .output("output.mp4")
  .output("output.webm");

for await (const process: EncodingProcess of encoder) {
  process.run();
  spinner.start();
  for await (const event: EncodingEvent of process) {
    switch (event.type) {
      case "start":
        spinner.text = `Loading meta data: ${event.encoding.output} ...`;
        break;
      case "info":
        spinner.text = `Start encoding: ${event.encoding.output} ...`;
        break;
      case "progress":
        spinner.text = `Encode: <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mrow><mi>e</mi><mi>v</mi><mi>e</mi><mi>n</mi><mi>t</mi><mi mathvariant="normal">.</mi><mi>e</mi><mi>n</mi><mi>c</mi><mi>o</mi><mi>d</mi><mi>i</mi><mi>n</mi><mi>g</mi><mi mathvariant="normal">.</mi><mi>o</mi><mi>u</mi><mi>t</mi><mi>p</mi><mi>u</mi><mi>t</mi></mrow><mo>−</mo></mrow><annotation encoding="application/x-tex">{event.encoding.output} - </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="mord"><span class="mord mathnormal">e</span><span class="mord mathnormal" style="margin-right:0.03588em;">v</span><span class="mord mathnormal">e</span><span class="mord mathnormal">n</span><span class="mord mathnormal">t</span><span class="mord">.</span><span class="mord mathnormal">e</span><span class="mord mathnormal">n</span><span class="mord mathnormal">co</span><span class="mord mathnormal">d</span><span class="mord mathnormal">in</span><span class="mord mathnormal" style="margin-right:0.03588em;">g</span><span class="mord">.</span><span class="mord mathnormal">o</span><span class="mord mathnormal">u</span><span class="mord mathnormal">tp</span><span class="mord mathnormal">u</span><span class="mord mathnormal">t</span></span><span class="mord">−</span></span></span></span>{event.progress}%`;
        break;
      case "end":
        spinner.stop();
        process.close();
        console.log(`✔ Encode: ${process.encoding.output} - 100%`);
        break;
      case "error":
        spinner.stop();
        process.close();
        console.log(`✘ Encode: ${process.encoding.output} - failed!`);
        throw event.error;
    }
  }
}

console.log("All encodings done!");

$ deno run --allow-read --allow-run --unstable https://deno.land/x/fast_forward/examples/event-stream.ts

Output Stream

const encoder = ffmpeg("https://www.w3schools.com/html/mov_bbb.mp4")
  .output("pipe:1")
  .format("mp4")
  .videoBitrate("933k")
  .audioBitrate("128k")
  .args(["-movflags", "frag_keyframe+empty_moov"]);

for await (const process: EncodingProcess of encoder) {
  process.run();
  if (process.stdout) {
    const outputFile: Deno.File = await Deno.open("output.mp4", {
      create: true,
      write: true,
    });
    const [status] = await Promise.all([
      process.status(),
      Deno.copy(process.stdout, outputFile),
    ]);
    console.log({ status });
  }
  process.close();
}

console.log("Encoding done!");

$ deno run --allow-read --allow-write --allow-run https://deno.land/x/fast_forward/examples/output-stream.ts

Todos

Options

output
- support multiple outputs
input
- support multiple inputs
cwd
binary
override
format
codec
audioCodec
videoCodec
audioBitrate
videoBitrate
minVideoBitrate
maxVideoBitrate
videoBufSize
width
height
rotate
noAudio
noVideo
noSubtitle
logLevel
args
seek
duration
loop
preset (name,path)
watermark
sampleRate
audioQuality
audioChannels
audioFilters
videoFilters
metadata
volume
frames
frameSize/size
fps/frameRate/rate
aspectRatio/aspect
loudnorm/normalize
autopad
keepDAR
map (map streams in container)
add input options
thumbnails
concat/merge (merge input files)
split (split output file by size/time)

Methods

getAvailableFilters()
getAvailableCodecs()
getAvailableEncoders()
getAvailableFormats()
validate()/checkCapabilities()
thumbnail()/thumbnails()
flipVertical/flipHorizontal
rotate()

Events

start
info/meta/metadata
progress
end
error
stderr (ffmpeg output)

Contributing

Any kind of contribution is welcome! Please take a look at the contributing guidelines.

License

MIT

Fast Forward

Contents

Installation

Usage

Getting Started

Examples

Events

Process handling

Event Stream

Output Stream

Todos

Options

Methods

Events

Contributing

License