Resize & Aspect Ratio

Control video dimensions and proportions for any player or platform

Overview

AutoRender allows you to resize videos to exact dimensions or force specific aspect ratios while maintaining visual quality. Dimensions are automatically optimized for video encoding compatibility.

Basic Resize - (w, h)

Specify the output width and height in pixels. If only one dimension is provided, the other is calculated automatically to maintain the original proportion.

Parameter	Range	Description
w_	1 to 4320	Sets the output width
h_	1 to 4320	Sets the output height

Original (16:9)

Resized (w_400)

https://assets.autorender.io/LOKVTtKVGb/w_400/doc/skateboarding.mp4

Aspect Ratio - (ar)

Force a specific proportion (e.g., 1:1 for social feeds) regardless of the source video’s original ratio.

Common Ratios: ar_1:1, ar_16:9, ar_9:16, ar_4:5

Original (16:9)

Square (ar_1:1)

https://assets.autorender.io/LOKVTtKVGb/w_400,ar_1:1/doc/skateboarding.mp4

Padding & Extraction - (cm)

Control how the video fills the specified dimensions. This is essential when trying to fit a widescreen video into a square frame without cropping important content.

• cm_pad_resize: Resizes the video to fit within the dimensions and adds padding to fill the empty space.
• cm_extract: Crops the video to fill the exact dimensions.

Background Color - (bg)

When using cm_pad_resize, you can specify the color of the padding area.

Parameter	Values	Description
bg_{c}	white, 000000	Sets the padding color (Name or Hex)

Original (16:9)

Padded (400x400)

https://assets.autorender.io/LOKVTtKVGb/w_400,h_400,cm_pad_resize,bg_white/doc/skateboarding.mp4

Best Practices

• Maintain Ratios: Use ar_ whenever possible to ensure your video stays correctly proportioned across devices.
• Optimization: Smaller dimensions result in significantly faster initial processing and lower bandwidth costs.
• Encoding: AutoRender handles all the technical complexity of aspect ratio padding and coordinate snapping for you.