dts/ac3 passthrough broken?

[gsmd]

My config is an LCD TV connected over HDMI to Gentoo box and Logitech z-5500 ac3/dts decoder connected to TV over optical. Never had problems playing any movies in WinXP.

mplayer dtsmovie.mkv -ao alsa:device=plughw=1.3
This plays. Only 2 channels and software decoding, right?

mplayer dtsmovie.mkv -ac hwdts -ao alsa:device=plughw=1.3
This doesn't. What I hear is just varying noise out of speakers.

Could anyone with working sound-over-hdmi verify this? Could it be that there's something broken inside fglrx?

TIA.

[domi]

You don't need to specify the device when using -ac hwdts

I.e. this should work:
mplayer dtsmovie.mkv -ac hwdts

Last but not least, fglrx code is not involved in sending sound to optical SPDIF. Only mplayer and alsa

All the best

[gsmd]

domi
The audio is channeled through hdmi, not optical.

[domi]

domi
The audio is channeled through hdmi, not optical.

Oops, sorry.

Still, specifying the alsa device when using hwdts (or hwac3) is tricky. For instance, I don't think you can use plughw. Try with just -ao alsa:device=hw=1.3

HTH

[Kano]

I thought HDMI paththrough never existed?

[domi]

I thought HDMI paththrough never existed?

This may depend on HDMI version. I know that HDMI 1.3 is able to carry encoded audio stream (i.e. HD DTS, Dolby true HD ...)

The answer I gave before are based on my knowledge of mplayer and alsa, but I have no experience with HDMI on Linux (I only have DVI output on my graphical card). So what I say must be taken with a grain of salt.

HTH

[Kano]

And which HDMI version is supported by the card?

[gsmd]

domi
Hey, thanks for your replies. I'll try what you've suggested to see if it makes any difference. But, to tell the truth, I care little about mplayer at the moment, just that it it behaves exactly the way XBMC does: with 'hardware decoding' option set for the audio device in the UI, I get exactly the same noise I get with mplayer.

Kano
Gigabyte states (http://www.gigabyte.com.tw/Products/Motherboard/Products_Overview.aspx?ProductID=2758) it's 1.3.

[gsmd]

Well, I know what the problem is: what I'm trying to do is a dumbshit ;).
Sending DTS to any TV over HDMI makes no sense at all as TV can't decode it. The DTS receiver connected to TV via optical would receive stereo only. Unfortunately, there's no such thing as digital sound passthrough for TVs (which would definitely make sense).