This indeed does snap to keyframes when input seeking is used. On output seeking, it cuts the video at the exact time, but there isn't enough information to re

This indeed does snap to keyframes when input seeking is used. On output seeking, it cuts the video at the exact time, but there isn't enough information to rebuild the image as it's still a truncated copy of the stream. It's possible to reencode a (h264-encoded, at least) video up to the first keyframe; it's discussed in this StackExchange submission: https://video.stackexchange.com/a/23542 https://video.stackexchange.com/a/23542 Coincidentally, I refined the above approach very recently and posted the result to my own blog: https://csrd.science/blag/2020/trimming-an-h264-video-and-preserving-most-of-the-original-video-stream.html https://csrd.science/blag/2020/trimming-an-h264-video-and-pr... The gist is to extract and reencode the segment containing the group of pictures to be cut (using the stream segment muxer), then rejoin the subsequent segments and remux the trimmed audio back in afterwards.