I'm doing a time-lapse film project about a six-month period. Now I write a script to process the thousands of photos. I use ffmpeg. The paths to the photos are in the list.tmp file and i'm using the concat option.
ffmpeg -r 400 -f concat -safe 0 -i list.tmp -video_size hd1080 -vcodec libx264 -preset medium -crf 23 timelapse.mkv
With this command I get a time lapse with 400fps. If I now set the frame rate of the output video to 25fps, the film still looks the same subjective, but is a lot smaller (15mb instead of 60mb).
ffmpeg -r 400 -f concat -safe 0 -i list.tmp -r 25 -video_size hd1080 -vcodec libx264 -preset medium -crf 23 timelapse.mkv
ffmpeg also reports that most images were droped.
frame= 201 fps=3.7 q=-1.0 Lsize= 15647kB time=00:00:07.92 bitrate=16181.8kbits/s dup=0 drop=2989 speed=0.148x
Is it so, that I don't see the difference between 25fps and 400fps because people perceive 25fps as a smooth video?
Sorry for my English.