run2-ffmpeg-keyframes

name	run2_ffmpeg-keyframes
description	Extract I-frame keyframes from video files using FFmpeg CLI, saving as zero-padded PNG sequences starting at 001.

FFmpeg Keyframe Extraction

Prerequisites

• FFmpeg installed: sudo apt install ffmpeg

Extract Keyframes (I-frames) as PNG Sequence

ffmpeg -i <input_video> -vf "select='eq(pict_type,I)'" -vsync vfr <output_dir>/keyframes_%03d.png

Example

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

Output

• Files named: keyframes_001.png, keyframes_002.png, ..., up to total keyframe count
• Files are in RGB color (PNG format, 3-channel)
• Frame index starts at 001
• Timeline order is preserved (sorted by video timestamp)

Key Flags

• -vf "select='eq(pict_type,I)'" — selects only I-frames (keyframes)
• -vsync vfr — avoids duplicate frame output

Notes

• The number of keyframes depends on the video's encoding (GOP size)
• PNG output is lossless and RGB by default
• To list extracted files in order: ls /root/keyframes_*.png | sort