I have a similar problem with an older device and to allow playback I devised a successful encode with FFmpeg that can easily enough be wrapped up in a WinFF preset.
First make sure that you have a full WinFF installation:
sudo apt-get install winff winff-doc ffmpeg libavcodec-extra
Then create a file on your desktop called called torrent2tv.wff and copy and paste the following xml snippet into it:
<?xml version="1.0" encoding="utf-8"?>
<presets>
<TORRENT2TV>
<label>Convert to avi for viewing through old device!</label>
<params>-c:v mpeg4 -q:v 2 -vtag XVID -sn -mbd rd -flags +mv4+aic -trellis 2 -cmp 2 -subcmp 2 -g 300 -c:a libmp3lame -ac 2 -q:a 3 -ar 44100 </params>
<extension>avi</extension>
<category>My Presets</category>
</TORRENT2TV>
</presets>
Right click on this file and select 'Open With WinFF' and this will be enough to install your preset into a new category called 'My Presets'.
Select this and run you input torrent files and hopefully your playback will be as good as mine on my own aged device :).