Choppy transcoded video, only with live transcoding

I have a .Mov video from a nikon camera that needs transcoding when sent to my panasonic viera tv.
When serviio transcodes it live and sent it to my tv, the video results choppy.
First check was cpu usage and it didn't go over 8%.
Second check was network usage and it didn't go over 40%.
Last test was to play the already transcoded file and it was perfect.

what else can slow my video playing with the live transcoding?

thanks!
pdneri

[Illico]

When serviio transcodes it live and sent it to my tv, the video results choppy.
...
Last test was to play the already transcoded file and it was perfect.

If the already transcoded file was perfect --> ffmpeg command line option used are good.
if the video results choppy when transcoded in fly --> probably due to low cpu process, the result transcoding procces is too slow compared to frame rate.
On serviio console, do you select more than one cpus for transcoding process?
You could also try the ffmpeg command line locally (found in detailed serviio logging file) in windows terminal and check the computing rate (fps).

Thanks for your answer!
I confirm that the already transcoded file plays perfectly and so ffmpeg options are ok.
I don't believe there is a problem at cpu level, because I have an i7 cpu with 8 cores and I chose 8 cpu in serviio options.
In fact cpu usage goes from 3% to 8% when transcoding in fly.
On network side, with lan cables (100 Mbit), instead of wifi, it is less choppy. But the already transcoded file via wifi plays good.
I think there is something different on network throughput when playing in fly compared to playing a non-transcoded file.