video-keyframe-extraction

name	video-keyframe-extraction
description	Extract key frames (I-frames) from video files using FFmpeg. Use this skill when the user needs to pull out keyframes from MP4, MKV, AVI, or other video formats for analysis or processing.

Video Keyframe Extraction

Extract I-frames (keyframes) from video files using FFmpeg's select filter.

Command

ffmpeg -i <input_video> -vf "select=eq(pict_type\,I)" -vsync vfr <output_pattern>

• -vf "select=eq(pict_type\,I)" selects only I-frames (intra-coded frames, the "key" frames in video compression)
• -vsync vfr uses variable frame rate to avoid duplicating frames
• Output pattern uses %03d for sequential numbering: e.g., keyframes_%03d.png

Example

ffmpeg -i /root/video.mp4 -vf "select=eq(pict_type\,I)" -vsync vfr /root/keyframes_%03d.png

This produces /root/keyframes_001.png, /root/keyframes_002.png, etc., one per I-frame in timeline order.

Notes

• I-frames are complete images (not predicted from other frames), making them ideal for analysis
• The number of keyframes depends on the video's encoding settings (typically every 1-2 seconds)
• Output is in timeline order by default