I'd like to repeat one frame from a source video to output. I've tried the following
avconv -ss 00:20:00 -i INPUT_VIDEO -t 0.5 -vsync 1 -an -r 1 -vcodec libx264 VIDEO_1F avconv -i VIDEO_1F -t 10 -r 1 -vcodec libx264 OUTPUT_VIDEO
But I found that
-ss doesn't work in the former command, and it would always extract the first frame of input video; in the latter
-t has no effects and the duration of the output video will be 2 seconds.
Any suggestion? Or, is there a better approach?