John Robinson schrieb:

> One member of this list very helpfully
> suggested that, to switch between the programme's main sound track and
> the audio description track, I can hit the 'Audio' key, then the right
> cursor key and then the 'Audio' key again.  This does, indeed switch
> from the main programme sound track to the audio description track, but
> it only lets me hear one or the other, not both.

Maybe I told you too much details of the audio menu so you got a
bit confused. Your key sequence 'Audio', 'right cursor', 'Audio'
may indeed do, what you experience. Let me explain:

1.) 'Audio' opens the audio menu.
2.) 'right cursor' selects the right channel of the current
stereo track.
3.) 'Audio' switches to the next track (audio description) but
stays at right channel of the audio description track.

At the moment, there is no programme running where I could verify
my conclusions, but for me it looks like that (referencing the
explanations of my previous email): the audio description track
provides two mono channels which appear as left and right channel
of the stereo audio description track. The left channel seems to
provide a mono audio signal of the main programmes sound track,
while the right channel provides audio description only.

So simply omitting step two 'right cursor' from your key sequence
should do the trick and present both mono channels at the same
time. The only drawback of the current solution is, that you hear
the main programme sound track only on the left side of your
audio equipment and the audio description only on the right side.

Mixing both mono channels together and presenting the result as a
stereo signal is feasible by output plugins but would require
some way to tell the output plugin to activate this mode. The
best would be if VDR's user interface would allow to select such
a mode and provide that selection to the output plugin.

Suggestion for extending the user and output plugin interface: In
the audio menu, the left and right keys select between left,
stereo and right channel. A further mode 'combined' should be
added which can be reached by pressing 'right' when the right
channel is selected. The current audio channel selection is
provided in the output plugin interface via the method
SetAudioChannelDevice. The parameter values 0, 1 or 2 represent
stereo, left or right channel. A further parameter value 3 would
represent 'combined' mode. For compatibility and the most common
use case, 'combined' mode should need to be activated in VDR's
setup menu, i. e. it is not available by default.

Maybe Klaus can drop a few words about this extension.

Dipl.-Inform. (FH) Reinhard Nissl

vdr mailing list

Reply via email to