#732 Audio passthrough

[Alfredo Monclus]

The option to pass AC3/DTS through SPDIF can be improved easily, currently i have the option disabled and pass this argument to MPV (works perfectly for the HD audio modes):

--audio-spdif=dts-hd,truehd,eac3,ac3

Also the name should be changed to something like "Bitstream Passtrough over SPDIF and HDMI" (since it works for both interfaces)

[Mathieu Martin]

In my case adding the custom option : --audio-spdif=dts-hd,truehd,eac3,ac3
wasn't enough to have compressed audio passthrough HDMI.
On a DTS audio file, my AVR was still receiving uncompressed PCM stream.

Using mpv by command line (0.16.0), I was able to trully passtrough by adding --audio-device='alsa/hdmi:CARD=HDMI,DEV=2' instead of --ao=alsa:device=[hw:1,8].
(of course card and device number depend on the hardware)
The AVR was decoding a DTS compressed stream instead of PCM, meaning the passthrough was correctly done.

With smplayer (16.4.0), i wasn't able to obtain the same result.
I known that currently smplayer with mpv uses --ao=..... instead of --audio-device='....'
But I tried to do a trick in smplayer by setting the audio driver output to "user defined" and let it empty and setting the additionnal option I talked before --audio-device='alsa/hdmi:CARD=HDMI,DEV=2'
But doing this, I didnt get any sound, even though the mpv cmd line launch by smplayer seems ok : the --ao argument was no more present and the --audio-device='...' one was.

[Ricardo Villalba]

I think this is fixed in svn r8754.