Frame Rate
Frame Rate (Frames Per Second)
The number of individual still images (frames) displayed per second in a video, determining the smoothness of motion. Common frame rates include 24 fps (cinema), 30 fps (broadcast), and 60 fps (gaming and sports).
技術的詳細
Frame rate directly impacts file size: doubling fps roughly doubles the data rate at the same quality. Standard rates include 23.976 fps (NTSC film, often called 24p), 25 fps (PAL), 29.97 fps (NTSC broadcast), 30 fps, 50 fps (PAL smooth), 59.94 fps, and 60 fps. Variable Frame Rate (VFR) adjusts dynamically (common in screen recordings and smartphone video). Higher frame rates (120, 240 fps) are used for slow-motion playback. The requestAnimationFrame() API targets the display's native refresh rate (~60 fps on most monitors), while video playback respects the embedded frame rate metadata.
例
``` Frame rate standards: 24 fps — Cinema (film look) 25 fps — PAL TV (Europe, Asia) 30 fps — NTSC TV, web video (US, Japan) 60 fps — Gaming, sports, smooth motion 120 fps — Slow motion (played at 30 fps = 4x slow) File size: doubling fps roughly doubles file size Web standard: 30 fps for best quality/bandwidth balance ```