Workflow Utilities | Video to Video

fal-ai/workflow-utilities/scale-video

FFMPEG Utilities to Scale Videos

Inference

Commercial use

Schema

LLMs

Playground API

About

Scale/resize a video to specific dimensions.

Three modes are available:

stretch: Scale to exact dimensions (may distort aspect ratio)
pad: Scale to fit within dimensions preserving aspect ratio, pad remaining space
crop: Scale to cover dimensions preserving aspect ratio, center-crop to fit

1. Calling the API#

Install the client#

The client provides a convenient way to interact with the model API.

npm install --save @fal-ai/client

Migrate to @fal-ai/client

The @fal-ai/serverless-client package has been deprecated in favor of @fal-ai/client. Please check the migration guide for more information.

Setup your API Key#

Set FAL_KEY as an environment variable in your runtime.

export FAL_KEY="YOUR_API_KEY"

Submit a request#

The client API handles the API submit protocol. It will handle the request status updates and return the result when the request is completed.

import { fal } from "@fal-ai/client";

const result = await fal.subscribe("fal-ai/workflow-utilities/scale-video", {
  input: {
    video_url: "https://storage.googleapis.com/falserverless/example_outputs/wan-25-i2v-output.mp4",
    width: 1920,
    height: 1080
  },
  logs: true,
  onQueueUpdate: (update) => {
    if (update.status === "IN_PROGRESS") {
      update.logs.map((log) => log.message).forEach(console.log);
    }
  },
});
console.log(result.data);
console.log(result.requestId);

2. Authentication#

The API uses an API Key for authentication. It is recommended you set the FAL_KEY environment variable in your runtime when possible.

API Key#

In case your app is running in an environment where you cannot set environment variables, you can set the API Key manually as a client configuration.

import { fal } from "@fal-ai/client";

fal.config({
  credentials: "YOUR_FAL_KEY"
});

Protect your API Key

When running code on the client-side (e.g. in a browser, mobile app or GUI applications), make sure to not expose your FAL_KEY. Instead, use a server-side proxy to make requests to the API. For more information, check out our server-side integration guide.

3. Queue#

Long-running requests

For long-running requests, such as training jobs or models with slower inference times, it is recommended to check the Queue status and rely on Webhooks instead of blocking while waiting for the result.

Submit a request#

The client API provides a convenient way to submit requests to the model.

import { fal } from "@fal-ai/client";

const { request_id } = await fal.queue.submit("fal-ai/workflow-utilities/scale-video", {
  input: {
    video_url: "https://storage.googleapis.com/falserverless/example_outputs/wan-25-i2v-output.mp4",
    width: 1920,
    height: 1080
  },
  webhookUrl: "https://optional.webhook.url/for/results",
});

Fetch request status#

You can fetch the status of a request to check if it is completed or still in progress.

import { fal } from "@fal-ai/client";

const status = await fal.queue.status("fal-ai/workflow-utilities/scale-video", {
  requestId: "764cabcf-b745-4b3e-ae38-1200304cf45b",
  logs: true,
});

Get the result#

Once the request is completed, you can fetch the result. See the Output Schema for the expected result format.

import { fal } from "@fal-ai/client";

const result = await fal.queue.result("fal-ai/workflow-utilities/scale-video", {
  requestId: "764cabcf-b745-4b3e-ae38-1200304cf45b"
});
console.log(result.data);
console.log(result.requestId);

4. Files#

Some attributes in the API accept file URLs as input. Whenever that's the case you can pass your own URL or a Base64 data URI.

Data URI (base64)#

You can pass a Base64 data URI as a file input. The API will handle the file decoding for you. Keep in mind that for large files, this alternative although convenient can impact the request performance.

Hosted files (URL)#

You can also pass your own URLs as long as they are publicly accessible. Be aware that some hosts might block cross-site requests, rate-limit, or consider the request as a bot.

Uploading files#

We provide a convenient file storage that allows you to upload files and use them in your requests. You can upload files using the client API and use the returned URL in your requests.

import { fal } from "@fal-ai/client";

const file = new File(["Hello, World!"], "hello.txt", { type: "text/plain" });
const url = await fal.storage.upload(file);

Auto uploads

The client will auto-upload the file for you if you pass a binary object (e.g. File, Data).

Read more about file handling in our file upload guide.

5. Schema#

Input#

video_url string* required

URL of the video file to scale/resize. Height and Width of the video must be even numbers for compatibility with video codecs.

Max file size: 476.8MB, Timeout: 30.0s

width integer* required

Target width in pixels

height integer* required

Target height in pixels

mode ModeEnum

Scaling mode. 'stretch' scales the video to the exact target dimensions (may distort aspect ratio). 'pad' scales to fit within the target dimensions while preserving aspect ratio, then pads with the chosen color to fill the remaining space (letterbox/pillarbox). 'crop' scales to cover the target dimensions while preserving aspect ratio, then center-crops to the exact target size. Default value: "stretch"

Possible enum values: stretch, pad, crop

pad_color PadColorEnum

Padding color when mode is 'pad'. Ignored for other modes. Default value: "black"

Possible enum values: black, white, red, green, blue, gray

codec CodecEnum

Video codec to use for encoding. libx264 (H.264) is widely compatible, libx265 (H.265/HEVC) offers better compression. Default value: "libx264"

Possible enum values: libx264, libx265

preset PresetEnum

Encoding speed preset. Slower presets give better compression but take longer. Default value: "fast"

Possible enum values: ultrafast, fast, medium, slow

crf integer

Constant Rate Factor for quality (0-51). Lower values mean better quality and larger files. 18 is visually lossless for most content. Default value: 18

{
  "video_url": "https://storage.googleapis.com/falserverless/example_outputs/wan-25-i2v-output.mp4",
  "width": 1920,
  "height": 1080,
  "mode": "stretch",
  "pad_color": "black",
  "codec": "libx264",
  "preset": "fast",
  "crf": 18
}

Output#

video File* required

The scaled/resized video

original_width integer* required

Width of the original video in pixels

original_height integer* required

Height of the original video in pixels

scaled_width integer* required

Width of the output video in pixels

scaled_height integer* required

Height of the output video in pixels

{
  "video": {
    "file_size": 3456789,
    "file_name": "output.mp4",
    "content_type": "video/mp4",
    "url": "https://v3b.fal.media/files/b/monkey/scaled_output.mp4"
  },
  "original_width": 1929,
  "original_height": 1082,
  "scaled_width": 1920,
  "scaled_height": 1080
}

Other types#

Image#

url string* required

The URL where the file can be downloaded from.

content_type string

The mime type of the file.

file_name string

The name of the file. It will be auto-generated if not provided.

file_size integer

The size of the file in bytes.

file_data string

File data

width integer

The width of the image in pixels.

height integer

The height of the image in pixels.

AudioFile#

url string* required

URL of the audio file

content_type string* required

Content type of the audio file

file_name string* required

Name of the audio file

file_size integer* required

Size of the audio file in bytes

SubtitleSegment#

start float* required

Start time in seconds (e.g., 0.0 for beginning, 5.5 for 5.5 seconds)

end float* required

End time in seconds (must be greater than start time)

text string* required

Subtitle text to display (supports multiple lines with )

File#

url string* required

The URL where the file can be downloaded from.

content_type string

The mime type of the file.

file_name string

The name of the file. It will be auto-generated if not provided.

file_size integer

The size of the file in bytes.

file_data string

File data

EQBand#

frequency float* required

Center frequency in Hz (20-20000)

width float

Bandwidth in Hz Default value: 100

gain float* required

Gain in dB (-30 to 30, negative = cut, positive = boost)

Workflow Utilities Video to Video

Table of contents

1. Calling the API

2. Authentication

3. Queue

4. Files

5. Schema

About

1. Calling the API#

Install the client#

Migrate to @fal-ai/client

Setup your API Key#

Submit a request#

2. Authentication#

API Key#

Protect your API Key

3. Queue#

Long-running requests

Submit a request#

Fetch request status#

Get the result#

4. Files#

Data URI (base64)#

Hosted files (URL)#

Uploading files#

Auto uploads

5. Schema#

Input#

Output#

Other types#

Image#

AudioFile#

SubtitleSegment#

File#

EQBand#