Problem with ffmpeg which happens randomly

[payamhd]

Hello. I have a few ffmpeg commands to convert video to 480p and 720p. The thing is sometimes my output video have a problem. when you play the video sometimes it gets stuck at a specific time. it's sort of like it's missing those seconds. then if you seek forward the video it'll continue playing. this happens so random and even if I encode a video twice the time isn't the same and sometimes it won't even happen. can you guys guess what the problem is?
Another problem like this also happen which makes a random frame blur. something like this:


[Attachment 77043 - Click to enlarge]

here's the code I use for 720p:

ffmpeg -i "$sourcePath" -c:v libx264 -crf 23 -movflags +faststart -vf 'scale=1280:-2:flags=lanczos,smartblur=1.5:-0.35:-3.5:0.65:0.25:2.0,format=yuv420p,subtitles='$foldername'/hardsub.srt:force_style=Fontsize=22,FontName=IRANSansX,PrimaryColour=&H00F2FF&,MarginV=17,drawtext=text=MyTagName:x=w-tw-10:y=H-th-10:fontfile=AvenirLTStdBlack.otf:fontsize=15:fontcolor=white:box=1:boxcolor=white@0.5:boxborderw=5:enable=between(t\,10\,17),drawtext=text=MyTagName:x=10:y=H-th-10:fontfile=AvenirLTStdBlack.otf:fontsize=15:fontcolor=white:box=1:boxcolor=white@0.5:boxborderw=5:enable=between(t\,18\,25),drawtext=text=MyTagName:x=w-tw-10:y=10:fontfile=AvenirLTStdBlack.otf:fontsize=15:fontcolor=white:box=1:boxcolor=white@0.5:boxborderw=5:enable=between'$valueMid1',drawtext=text=MyTagName:x=10:y=10:fontfile=AvenirLTStdBlack.otf:fontsize=15:fontcolor=white:box=1:boxcolor=white@0.5:boxborderw=5:enable=between'$valueMid2',drawtext=text=MyTagName:x=w-tw-10:y=H-th-10:fontfile=AvenirLTStdBlack.otf:fontsize=15:fontcolor=white:box=1:boxcolor=white@0.5:boxborderw=5:enable=between'$valueEnd1',drawtext=text=MyTagName:x=10:y=H-th-10:fontfile=AvenirLTStdBlack.otf:fontsize=15:fontcolor=white:box=1:boxcolor=white@0.5:boxborderw=5:enable=between'$valueEnd2"'" -x264opts ref=3:subme=7:trellis=1:rc_lookahead=40 -colorspace bt709 -preset veryfast -ac 2 -c:a aac -strict -2 -b:a 128k -map 0:a:0 -map 0:v -map 0:s? -sn "$foldername/output/$outputname"

[vongooB9]

These problems occur when the video file is corrupted. If it were a downloaded video it is most likely that the download went wrong, but in your case, as you are generating the file yourself, it is a symptom of a hardware failure. Possibly a hard disk or RAM failure, but it could be anything.

[rgr]

Remove all filters, convert and check.
Or maybe your player doesn't play properly? Post a fragment.