I can’t troubleshoot now, but from the experience with YT rips and trying to transcode them, usually makes them either bigger or corrupted. We’ve seen a fair share of such uploads in the past. You can try “curl -O <url>” and then use ffprobe to see what is going on with it. Usually it is either broken bframe or something to that tune. Uploading the direct YT download is the most optimal way to share them. 

 IMO amethyst using handbrake solves this issue 

 YT videos are already well compressed and none of the transcoding makes them smaller at the same resolution. And yes, ffmpeg based solutions are much better 

 Times out in amethyst. YTDLnis rips YUGE videos from YT. I always have to handbrake them. Been having issues with the app lately. Over 200mb for a 10 min video.  

 try going to https://nostr.build/account/ and upload from there 

 [mov,mp4,m4a,3gp,3g2,mj2 @ 0x74f36ad5e580] moov atom not found
45RoBbHjcuJSq3V2.mp4: Invalid data found when processing input

File is corrupted, so just use web interface of NB and upload as is, no transcoding