从视频提取帧

For thumbnail generation, 1 fps (one frame per second) is usually ideal. This gives you a representative sample of the video without creating an overwhelming number of images. For a 60-second video, you'll get approximately 60 frames to choose from. If the video has fast-moving content and you need more options, try 2-3 fps instead.

JPEG produces smaller files (typically 50-200 KB per frame) and is best for thumbnails, web use, and general-purpose extraction where file size matters. PNG preserves exact pixel data with lossless compression (typically 500 KB - 2 MB per frame) and is better for detailed analysis, graphics with text, screenshots, and any use case where quality is critical. Choose JPEG for bulk extraction and PNG when precision matters.

The number of frames equals the video duration in seconds multiplied by the FPS rate, capped by your maximum frames setting. For example, a 30-second video at 2 fps produces up to 60 frames. If you set the max frames to 20, only the first 20 frames will be extracted. Use the max frames setting to control output volume, especially for longer videos.

The current tool extracts frames at regular intervals based on your chosen FPS rate, starting from the beginning of the video. To target a specific section, you can first trim the video using a video trimmer tool, then extract frames from the trimmed clip. This two-step approach gives you precise control over which portion of the video you capture frames from.

There is no strict time limit, but the video file size must fit within browser memory constraints. Videos up to a few hundred megabytes work well. For very long videos, keep the FPS low (1-2 fps) and set a reasonable max frame limit to avoid browser performance issues. Processing time increases with both video length and FPS rate, so find the right balance for your needs.