[mythtvnz] Recordings without audio

[Stephen Worthington]

On Sat, 5 Nov 2016 21:44:35 +1300, you wrote:

>Occasionally shows are recorded without any sound. Others on the same channel are fine. E.g.: TV3, recording 'Graham Norton' and (immediately following) '7 Days' - the first is OK, the second silent. I have two tuner cards; perhaps MythTV switches from one to the other between shows? The 'silent' problem only happens infrequently, maybe one show per month, so if it was a faulty tuner, I would expect to see it a lot more often. Anyone have any ideas?

As of MythTV 0.28, the database stores which card was used to make a
recording.  If you use the I key twice on a recording and scroll down
a bit, you see a field called "Recording Input".  This does rely on
your having set the displayname field for each tuner when you created
them.  If you did not do that, run mythtv-setup and add a displayname
that is different for each tuner.

Also, check when you play a 'silent' recording if it has alternate
audio tracks.  It may be that by default you are playing the wrong
audio track, and if a particular recording has more than one, the
others are not actually valid and do not have the proper sound.  Or
possibly there is 5.1 or 7.1 sound and your sound setup does not
handle that properly and produces no sound, where it works for a
normal stereo sound stream.  While playing, M > Audio > Select audio
track shows the list of available audio tracks.  Recent TV3 programmes
usually have both an AC-3 5.1 audio track and an AAC stereo track.
Older programmes (ones recorded a few years ago, but broadcast
recently) may only have AAC stereo.  TVNZ 1 programmes seem to have
both AAC and AC-3 audio, plus a second AAC audio track marked as
Italian language.  I have a feeling that if you play the Italian
audio, it will not actually be valid, but I have never actually tried
that.

If you have a 'silent' recording hanging around still, then you might
like to install the mediainfo package then run the mediainfo command
on the file for that recording, and post the results.  To find the
recording file for a particular recording, use the I command twice on
it and scroll down to the "Recorded File Name" field.  Then look for
that file in each directory where you store recordings.