Tvheadend

I am new to TVHeadend.
I have worked with VDR and MythTV and TVHeadend is by far the simplest in setup.
I have sucesfully compiled tvheadend and am pleasantly surprised with the easy setup.
I use the localhost:9981 to configure and schedule recordings.
The two dvb-T channels have been setup, all tv channels are listed. EPG works out of the box! (Great work).

When I configure a recording and look after the recording is supposed to have started. it displays "No input detected"

Any idea what I can do?

The next day I continued with a clean configuration.
The procedure that I followed:
- stopped tvheadend
- renamed /.hts to /.htsold
- started tvheadend (build.linux/tvheadend) as root
- reconfigured tv adapters:
.saved adapter configuration (DiBcom 7000PC)
.Add DVB network by location (New Zealand, Waiatarua)
.Map DVB references by channels
Configured a recording...and the recording worked fine.

Next, watching the recording.
I opened the file <NAME>.mkv with vlc player. It complained about the format:
--------------------------------------------------------------------------------------------------------
No suitable decoder module.
VLC does not support the audio or video format "undf". Unfortunately there is no way for you to fix this.
--------------------------------------------------------------------------------------------------------

VLC still played the file but with jumps in the video.
A recording made in VLC from a live stream looks more clear with clear audio and video quality.
Is this a problem with the recording or a shorcoming from VLC?
As an alternative approach:
Is there a way to use the ffmpeg codec with tvheadend?
What would you recommend for playing the recording with?
Do you need any logging for background information?