Building a MythTV PVR

Summary

Well, that was it. The system has been up and running for a week or two now, and appears to be doing everything it should, waking up and going to sleep as necessary. It is also monitorable via MythWeb (http://192.168.0.7/mythweb in my case). The following are a few points I have noticed in usage:

Recorded files

So far the recorded files all seem good. The only issues I have relate to import into Magix Movie Edit Pro 2016 (MEP) on a Windows system.

Occasionally although the whole file is there MEP will only 'see' the first few minutes. This is probably due to time markers changing between programs, and can be got around by rewriting the MPG file using VideoReDo TV Suite (it's a fast rewrite with no recoding so no quality is lost).

The other issue is very poor (and varying) lip sync on HD (H.264 / AAC) files when imported into MEP. I put this to Magix and they said the file format was at fault, however as these files play perfectly well into Windows Media Player, AVS, VideoReDo, VLC, play back fine in Kodi, and the MEP import has had the same problem with three different makes of tuner running on two different systems (Windows and Linux) and also files actually generated by VideoReDo, I feel there may be more to it.

In practice I get around this by recoding HD files into MPEG-2 program streams using VideoReDo; this is not ideal as it is an extra decode / recode with some minor potential loss of quality, but Magix have no plans to change the codec.

Finally MythTV does have this approach of not really deleting old recordings when asked (until space runs out), which is not what I want, but I hope I have largely disabled that, especially for live TV.

Updates and backup

One thing I have learnt is to backup the system partition. On one occasion I did back it all up, then downloaded all updates. The result of that on a reboot was nothing - totally trashed. Fortunately I had the backup and reloaded it. Next time it did not happen.

It just seems that maybe it is not as robust regarding things like updates as a Windows system, or maybe I was just unlucky. Either way, I don't want it happening again so I have now taken the view that once it is going as I wish, I probably will not keep updating as a matter of course as one does on a Windows system. There is no real security issue here - there is nothing secure stored on it.

For backup I use a commercial backup application.

If you have to replace the system partition and it does not fully match up with the recordings in the data partition, there may be orphaned recordings. There are scripts around for fixing this, but I have not so far investigated them.

Conclusions

It was a fair amount of work, but it does seem to work pretty well. The system unit sits behind the TV powering itself up and down as necessary. The only outstanding points are:

1. Getting HD channels to work with the 292e tuners
2. Managing overscan with an ATI Radeon graphics adapter and the open source driver
3. Considering a small UPS

It is now accessable from all over the house via wifi, however I have found that Kodi on a 2012 Google Nexus 7 tablet is not that useful - it has great difficulty in keeping up and spends a lot of time buffering. Streams with low bit rates are reasonable, BBC1 and 2 SD are pretty bad (higher bit rate) and anything HD is a non-starter. I think this is all down to the network speed of the tablet (it is pretty slow on most websites as well), and ordinary PCs and laptops (and probably faster tablets as well) are OK. I do notice that MythTV can transcode, so I will need to look into this. I don't know if it can do it on the fly.

This, in any case, was what I had to do to get my system to go, so I hope the information helps someone. It is fairly hard work, especially from zero knowledge of Linux, but worth it in the end.