[mythtv-users] Volume problems watching live-tv (ac3 vs. stereo)
arrikhan_mail at yahoo.com.au
Sat May 9 22:17:02 UTC 2009
Michael T. Dean wrote:
> On 05/09/2009 03:35 PM, Stefan Reichel wrote:
>> i have a little problem watching live tv. I use dvb-c, normally tv-shows
>> and commercials are transmitted with stereo sound, nevertheless some
>> movies will be broadcasted with AC3. In result when watching a movie
>> with ac3 sound volume is low, when the commercial begins, it gets stereo
>> and the sound volume raises dramatically.
>> Is there any way to get rid of these volume problems?
> Get 5.1 speakers?
>> Can i somehow
>> disable ac3 and convert it to stereo?
> If you're already doing 2-channel output (i.e. no AC-3/DTS passthrough
> and you have the "Max Audio Channels" setting*** set to "Stereo"--not
> "5.1"), it's already being done for you.
> If it /really/ concerns you, you can put a local hack in your own
> build of Myth similar to http://svn.mythtv.org/trac/changeset/15526 ,
> but note that it will /not/ be applied to "upstream" as current ffmpeg
> levels are appropriate.
> ***In frontend settings under the main General settings section just
> after the database settings on a page called, "Audio."
Whilst I went back to not having AC3 on my stereo (preamp went in for
repair) I had to fiddle with it and also alter mplayer settings to allow
This involved tweaking alsa-mixer to ensure I was downsampling to 2ch,
and adding oss function to the mplayer via the command line. Check out
alsamixer and see what options are enabled in there.
As I was passing AC3 through etc, and I had no decoder for AC3 anymore,
I didn't want to play around too much with AC3 as it took long enough to
get it working under my scenario. I was experiencing the same issue
whilst my preamp was being repaired and this tweaking seemed to fix the
I'm sorry I can't be more specific but I didn't write down what I did ..
just remembered that I altered it through alsamixer to ensure it was
outputting a 2channel signal from the source.
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