Re: audio output very low volume

Mon Jan 17 2005, Andrei A. Voropaev wrote:
> Hi!
> 
> I'm not very proficient with audio configuration, so maybe someone can
> help me here :)
> 
> On my laptop I have alsa sound. Other applications work ok, but in Ogle
> I can barely hear the sound. So I suspect that the problem is my
> configuration. I'm using the default one. My alsa driver is intel8x0.
> The odd part of my laptop is the fact that (possibly) built-in speakers
> are seen as headphones. At least to control the volume in alsamixer I
> use the slide for "headphones". The "master" slide does not play any
> role.
> 
> Any advice on what should I put in oglerc to get full sound volume on my
> built-in speakers?
> 
You should use the alsamixer to adjust the volume for Ogle also.  The defaults
in oglerc already adjust the audio to a higher volume. See this part

    <liba52>
      <downmix_level>1.5</downmix_level>
      <drc>no</drc>
      <stereo_mode>dolby</stereo_mode>
    </liba52>

The downmiz_level is a factor used to multiply the samples with when downmixing
multi-channel audio to stereo.  You can increase that but you will soon get
degraded sound when the samples overflow.  Enabling (set to yes) drc will, if
pressent, lower the dynamic range, i.e. make loud sounds quieter and quiet
sounds louder.  This is apropriate if you are truing to play DVDs on small
(computer) speakers.

Or perhaps it tries to play multichannel audio nativly?  If you run ogle --debug
it should print some information regarding this.  This is what I get for one
of my DVD: 

Debug[ogle_audio]: Searching <speakers> for:
Debug[ogle_audio]:  'Left' 'Right' 'Center' 'LeftSurround' 'RightSurround' 'LFE'
Debug[ogle_audio]: or for:
Debug[ogle_audio]:  'AC3'
Debug[ogle_audio]: No channel configs found
SNDCTL_DSP_GETCHANNELMASK: Invalid argument
Note[ogle_audio]: wanted 0 channels, got 2

The thing to notice here is the 'got 2' part, it means that it will try to
playback stereo sound, if it instead says 4, 5, or 6 then no downmixing will
happen.

/Håkan