Video CropperCrop videos to remove unwanted areas and change aspect ratios.

The Video Cropper uses the HTML5 Video element for playback and a Canvas overlay for the crop selection UI. The crop region is defined by x, y, width, and height coordinates relative to the video's native resolution. During processing, the video plays while each frame is drawn onto a Canvas using drawImage() with source and destination parameters that extract only the cropped region. The Canvas is sized to the crop dimensions, so the output matches the selected area exactly. The cropped canvas stream and audio (via Web Audio API) are fed to MediaRecorder for encoding. Preset aspect ratios are calculated based on the video's dimensions to provide commonly needed crop sizes.