frameSize

Framesize refers to the spatial dimensions of a single frame in a digital image or video, typically expressed as width by height in pixels (for example, 1920x1080). It defines the frame’s resolution and, together with frame rate, influences image quality, display compatibility, and data requirements.

Frame size is closely tied to aspect ratio—the proportional relationship between width and height. Common consumer video uses a 16:9 aspect ratio, but other ratios such as 4:3 or 21:9 are also used. The same frame size can map to different pixel aspect ratios if non-square pixels are involved, so display and encoding contexts may distinguish between frame size and display area.

In encoding and playback, larger frame sizes require more memory for storage and more processing power for decoding and rendering, and they typically lead to higher bitrates at a given quality. Many codecs and formats impose constraints on frame dimensions, often requiring widths and heights to be multiples of 8 or 16 due to underlying transform and macroblock structures. Some modern codecs support arbitrary sizes but may incur compatibility or efficiency trade-offs.

Applications and examples: in video production, frame size is chosen to match recording equipment, delivery formats, and target displays (common examples include 1920x1080 and 3840x2160). In image processing, frame size is simply the image dimensions, and resizing or cropping changes the frame size and can affect quality and aspect ratio.

In streaming and broadcasting, frame size may be adjusted dynamically to balance visual quality and bandwidth, and mismatches between content frame size and display aspect can produce letterboxing or stretching if not managed properly.