Slow on transcoding - QNAP 259+

Hello everybody,
had problems with the TMP folder. After solving that, all HD videos now playing but just shuttering
When trying to start the process manually i get the error:
Installed a new version off ffmpeg with ipkg and started the process:
But only getting fps between 20-35fps which is resulting in the shuttering
With 1080p mkv files, only 5 - 8 fps ...
Output of /opt/bin/ffmpeg -i:
When copying a file over GB Ethernet i get betweeen 60 - 80MB/sec. So i think the disc's aren't the problem. Have seen a thread here where users get more the 100 - 300fps
Someone with an explanation for that?
PS: PS3 Media Server plays the files just fine.
had problems with the TMP folder. After solving that, all HD videos now playing but just shuttering

When trying to start the process manually i get the error:
Installed a new version off ffmpeg with ipkg and started the process:
/opt/bin/ffmpeg -i /share/Qmultimedia/Filme/Colombiana.mkv -y -threads 4 -async 1 -vcodec mpeg2video -sameq -r 24000/1001 -g 15 -copyts -acodec ac3 -ab 384k -ac 2 -map 0:0 -map 0:1 -sn -f vob /root/.serviio/tmp/Serviio/transcoding-temp-56-MPEG2PS.stf
But only getting fps between 20-35fps which is resulting in the shuttering

Output of /opt/bin/ffmpeg -i:
- Code:
Fmpeg version UNKNOWN, Copyright (c) 2000-2008 Fabrice Bellard, et al.
configuration: --enable-cross-compile --cross-prefix=/home/slug/optware/ts509/toolchain/i686-unknown-linux-gnu/bin/i686-unknown-linux-gnu- --arch=i686 --disable-encoder=snow --disable-decoder=snow --enable-shared --disable-static --enable-gpl --enable-postproc --prefix=/opt
libavutil version: 49.6.0
libavcodec version: 51.54.0
libavformat version: 52.13.0
libavdevice version: 52.0.0
built on Feb 17 2012 14:25:30, gcc: 4.2.1
/opt/bin/ffmpeg: missing argument for option '-i'
When copying a file over GB Ethernet i get betweeen 60 - 80MB/sec. So i think the disc's aren't the problem. Have seen a thread here where users get more the 100 - 300fps

Someone with an explanation for that?
PS: PS3 Media Server plays the files just fine.