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Anamorphic crop calculator

Crop dimensions for 720×540 anamorphic video with 8/9 vertical squeeze adjustment.

Designed for 720×540 anamorphic video (typically NTSC DV). The image you upload must be exactly 720×540 pixels.

01SOURCE FRAME
drop an image · 720×540 required

drop image or click to browse

720×540 pixels required

02CROP REGION
width + x/y offsets in source pixels

03CALCULATIONS
computed values · derived from inputs

image size: ×

crop width:

crop height: = crop width × 3/4

adjusted height: = crop height × 8/9

adjusted Y offset: = Y offset × 8/9

about · how this works

What is this?

A specialized calculator for cropping anamorphic video content. Anamorphic video uses non-square pixels, which means stored dimensions differ from display dimensions. This tool calculates the correct crop parameters while accounting for the pixel aspect ratio.

How to use

  1. Extract a frame from your 720×540 anamorphic video
  2. Load the frame using the drop zone above
  3. Enter your desired crop width
  4. Adjust X and Y offsets to position the crop region
  5. Copy the generated crop filter and use it in your FFmpeg command

Background

Anamorphic video (particularly NTSC DV) is stored at 720×480 or 720×540 pixels but displays at 4:3 (640×480) or 16:9 (854×480) depending on the pixel aspect ratio. When cropping, you need to account for the vertical squeeze.

This tool uses an 8/9 vertical squeeze adjustment, appropriate for 4:3 DV content. Crop height is computed as width × 3/4 to maintain a 4:3 ratio, then × 8/9 to account for the anamorphic encoding.

The "likely full filter" output includes bwdif deinterlacing (common for DV footage), the crop filter with adjustments, scaling back to 720×540, and setting the pixel aspect ratio to square (1:1) with setsar=1.

$ crop filter

$ likely full filter