https://github.com/mifi/lossless-cut/pull/13
When I run ffmpeg with the arguments in this order -i ... -ss ... -t ..., it produces a video file that has no video for a few initial seconds. (as far as I can understand this is because it doesn't seek to a keyframe?)
If I change the order to -ss ... -i ... -t ..., then the resulting cut videos play properly.
My ffmpeg -version