Sound over DVI?

[MartjeB]

Hey,

I've got a Radeon HD3870. As you can see on the picture, it has two DVI outputs.

The strange thing is this (output of lspci):

05:00.0 VGA compatible controller: ATI Technologies Inc Radeon HD 3870
05:00.1 Audio device: ATI Technologies Inc Radeon HD 3870 Audio device

Three questions:

1. Is there a seperate audio chip on the videocard?
2. Can I convert my DVI to HDMI with audio?
3. Why doesn't Pulseaudio recognize this 'Audio device'?

Thanks

[nanonyme]

[*]Can I convert my DVI to HDMI with audio?

Yes, a DVI-HDMI adaptor should do.

[89c51]

according to Wikipedia DVI doesn't support audio signals and probably DVI to HDMI will only carry Video signal




i can only guess that you see the audio device because the chipset supports sound over HDMI/Displayport but you have only DVI output

except if the makers of the card use some non standars DVI that allows DVI with sound -> HDMI

[Zajec]

DVI and HDMI have the same pin[s]g[/s]s. I'm absolutely sure you can play audio using DVI to HDMI adapter connected to GPU, and then using HDMI cable. I'm doing that myself using RV635 with two DVI outputs.

I'm just not sure if using direct DVI to HDMI cable or DVI cable and DVI to HDMI adapter before monitor input will work. I think it should but didn't test.

Not sure about PulseAudio, but you can try mplayer and alsa for this. First of all check output of aplay -l. Look for HDMI:

card 1: HDMI [HDA ATI HDMI], device 3: ATI HDMI [ATI HDMI]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

and then use:

mplayer -ao alsa:device=hw=1.3 file.flac

Just make sure you use radeonhd 1.2.5 and

Option       "HDMI" "DVI-I_[12]"

[MartjeB]

Thanks Zajec

[nanonyme]

according to Wikipedia DVI doesn't support audio signals and probably DVI to HDMI will only carry Video signal

"However, the audio and remote-control features of HDMI will not be available unless the the output supports HDMI via a DVI plug" Read again what it says. The compatibility works only if the display adapter card supports encoding into what it sends into the cable. It says nothing of the sort that DVI to HDMI could only carry video signal. It also specifically says after my quote that it works with ATi 3xxx (probably implies RadeonHD 3xxx series and would actually range to RadeonHD 4xxx series) and nVidia 2xxGTX series. (Whatever that means)
You've been reading Wikipedia quite wrong.

[nanonyme]

[*]Why doesn't Pulseaudio recognize this 'Audio device'?

For this one I can only give my best guess if that's enough. Keep updating PulseAudio, it might be a compatibility problem somewhere. Zajec's way is good and sane but it bypasses PulseAudio which you might or might not want to do. If you want to keep using it, probably want to find out why it doesn't detect your card. I'd guess for a bug since iirc PulseAudio on my Fedora 11 detected the card just fine. (I wasn't able to test it since I don't have a TFT with speakers and HDMI input)

[89c51]

ok



anyway

[MartjeB]

Thanks nanonyme, I'll check the latest version of Pulseaudio, since I don't want to bypass Pulseaudio by using Alsa.