I have a 5 fps video with keyint 120 2.5 hours long that I want to speed up 6 times, making its fps=30
I did it with this command that I found somewhere on this website
ffmpeg -i "...local_Record.mkv" -filter:v "fps=30, setpts=PTS/6" "...output1.mkv"
The output came laggy, its playing for 3-5 seconds and then freezes. If I jump back or forward it unfreezes for another 3-5 seconds and then freezes again. After uploading it on youtube I found that its not lagging there, however youtube shows its length as original 2.5 hours. It also shows that its processing percent is 95% for 12+ hours already (which means that this video is 100% bugged and wont ever be processed, since its 90 mb and 20 min long, and youtube can process videos that 5 gb and hour long in 10 minutes)
Then I tried to re-encode the video I got with this command
ffmpeg -i "...mkv" -c:v libx264 -crf 18 -preset veryfast -max_muxing_queue_size 1024 output.mp4
Which gave me 133 mb result that is also shows on youtube as 2.5 hours long and never finishes processing (can be played, but its invisible, in video manager both videos say its 95% processed)
How to do it correctly, so that video would not lag and youtube could correctly get its length?
edit - I found what was the problem - there was some sound in container even though there werent supposed to be any sound at all (I recorded it with obs with no sound enabled). So after I removed that sound with mmg, mpc opened it correctly showing that its 26 minutes long and youtube successfully processed it in couple minutes