need to convert a few mkvs for plex

[towncarblue]

i recently bought myself a raspberry pi 3b and installed openelec { amber skin with plexbmc }
i get a "cache filled before reaching required amount " and the video starts to stutter after a minute .
it happens to some 720p files and all of my 1080p files { they are usually around 10gigs each }
some of my 720p videos play flawlessly , buffering takes only seconds.
ive tried to use handbrake to lower the resolution but the movies come out lower quality { all i did was lower the width to 1280 }
ive been searching web but i cant find no up to date tutorial on how to use handbrake.



i would like to know what is the best way to convert these videos so that they will stream excellently on plexbmc ?
what are the best settings ?

[jagabo]

You may not need to convert. There's a hack that increases the read-ahead buffer size. That may fix the problem. See #7:

http://www.htpcbeginner.com/raspberry-pi-openelec-tweaks/

[towncarblue]

thanks for the info. it did fix the issue i was having. the advancedsettings.xml file worked like a charm
i do need to use handbrake to make the files more web optimized so they load up quicker

[jagabo]

You can probably do that without re-encoding too. It's just a matter of moving header and keyframe information to the start of the file rather than the end. That can be done with the "-movflags faststart" option in ffmpeg. A command like:

ffmpeg -i source.mp4 -vcodec copy -acodec copy  -movflags faststart output.mp4

You can also use this method to remux from MKV to MP4 or vice versa by changing the input and output file extensions.