[MPlayer-users] What output driver for USB DAC?

[John Long]

On Sun, 2018-02-04 at 11:18 +0000, Andy Furniss wrote:
> John Long wrote:
> > On Sun, 2018-02-04 at 10:39 +0000, Andy Furniss wrote:
> > > John Long wrote:
> > > > Does anybody know how to get mplayer to send the correct signal
> > > > to a USB DAC?
> > > > 
> > > > If I play the file normally (mplayer filename) it appears
> > > > mplayer decodes the file before sending it to the DAC. I am
> > > > trying to get mplayer to send whatever type of signal to the
> > > > DAC
> > > > it needs so that the DAC itself will decode the music, not
> > > > mplayer.
> > > 
> > > If it's a DAC then it won't decode the many types of compressed 
> > > audio that mplayer/ffmpeg can.
> > 
> > That's ok, it supports everything I need it to play which is DSD
> > and 
> > FLAC.
> 
> OK so it is a decoder then - do the instructions/specs say what
> format
> input it needs?

No, as usual only MacOs and Windows are supported. It says MacOS works
natively but there is a driver download available for Windows.

> 
> > > A "normal" DAC takes PCM digital input and changes it to
> > > analogue.
> > 
> > I tried to use the PCM output from mplayer but it creates a file in
> > the current directory rather than playing it. And I suspect this
> > won't work for DSD since it is not PCM based.> Could you suggest
> > the
> > correct command line options to send the PCM stream to the default
> > device?
> 
> You shouldn't need to do anything, if mplayer decodes, what I called
> PCM/raw audio will be sent to alsa/pulse/jack as per setup which
> should
> then go to the device.

That's what I want but it seems from mplayers output messages it is
decoding the audio.

> 
> As for DSD I am not sure.

I will try to get it working with FLAC before I start looking into DSD.
But from what I understand from reading about DSD it is a totally
different encoding that PCW or RAW, it's just a stream of 1 bit data
representing whether the signal is rising (1) or falling (0).

If I can find out how to address the device maybe just cat would be
enough!

Thank you,

/jl
>