How do I use AC3 codec instead of PCM like mplayer -ac hwac3

[Alexander Motin]

Alexander Motin wrote:
> Norikatsu Shigemura wrote:
>>     I think that my snd_hda(4) device supports hardware AC3 codec
>>     (SEE ALSO: attached dmesg and sysctl messages).  But I couldn't
>>     mplayer -ac hwac3 dvd:// like following:
> 
> It looks like there is two problems:
> 
> First is yours: your default pcm0/dsp0 device is PCM only, it does not 
> supports AC3. Your SPDIF port is pcm1/dsp1. You should specify mplayer 
> to use it it you wish to pass AC3 through to the external decoder. Also 
> you have AC3 support as part of your video card HDMI port - pcm2/dsp2.
> 
> Second is at vchans: it does not support AC3 pass though when "Soft PCM 
> volume" is enabled. You can hack this by commenting respective part of 
> the hdac_audio_ctl_ossmixer_init(). Also it was reported that with some 
> amount of luck it may work even without it is you set pcm and master 
> volume on that channel to 100% and your decoder is able to detect 
> unmarked AC3 stream.

And the third problem is that vchans does not support "mixing" of AC3 
pass though, so you have to disable it for the respective device 
allowing only one application to use it at a time.

-- 
Alexander Motin