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

[Reimar Döffinger]

On 24.02.2018, at 21:04, John Long <codeblue-at-inbox.lv at ffmpeg.org> wrote:

> On Sat, 2018-02-24 at 16:12 +0100, Reimar Döffinger wrote:
>> On Sun, Feb 04, 2018 at 11:06:53AM +0000, 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.
>> 
>> I have some severe doubts about that.
>> For it to support FLAC, the playback application would need
>> to passthrough FLAC.
> 
> And this is what happens. Sorry for not being very clear.
> 
> It's not just a DAC. It's a streaming music player that supports DLNA,
> FLAC and a bunch of other CODECs over DLNA, and over USB.
> 
> It also has a USB DAC. Mplayer doesn't seem to get along with it but I
> am pretty sure it's not mplayer itself but some piece of Linux
> middleware. Which is how this question started.

A streaming music player is very different from a DAC/audio output device.
The most critical difference is that a DLNA player receives full files.
That avoids all the issues with having to define a framing format etc.
However that mode of operation is incompatible with any proper media player that wants to do more than send basic commands like "play file A" or "seek to position X".
If you want to control it via DLNA I'm afraid you'll need to use something other than MPlayer.
Maybe I misunderstood that part, but is there (after getting rid of pulseaudio etc) an issue with the DAC part? I am pretty sure now that playing FLAC in that mode by design is only possible by having MPlayer decode the audio, but that should not really be a problem?

Regards,
Reimar Döffinger