Tvheadend

If you aren't recording with configuration -> recording -> same as source (pass through) then select that.

If you already are then it's probably just the player failing to handle when the channels switch from 2 -> 5.1.

If you have the .ts file you could try chopping some off the front until you get a start with 5.1 sound using dd eg.

dd if=infile.ts of=outfile.ts bs=188 skip=100k

You'll have to play about with skip size just change and repeat until you get the right place.

Leave bs=188 as some players like vlc are fussy about ts starting on a packet boundary, also if you ever use vlc you need to set it to use ffmpeg for aac AIUI it will use libfaad2 by default, and that has a bug which causes the volume to pump when playing AAC with DRC metadata. I don't know what xbmc uses, but if you get it working and hear volume issues then tell it to use ffmpeg.

Thanks - I wasn't doing a pass through so have flipped to that and will see what happens.

Can I also do the skipping trick for MKV or do I now have a recording with no sound that I should jus t delete?

Thanks for the reply.

I don't really know whether the mkvs are saveable or not, maybe someone else will.

I suppose you could upload a sample somewhere like datafilehost.com chopped with dd but using count= instead of skip= so the first X meg needed to show the sound stopping + a bit could be seen.

The sound may still be there, but then it may not if was the encoding that went wrong at the switch point.

Unlike .ts .mkv are file based rather than a stream, so chopping off the front will loose the header and probably won't play (not that I've actually tested this).