[WillyB]

Volume control works fine for stereo audio sources, but when playing AC3/DTS sources I have no volume control within XBMC. The volume bar displays and moves, but the actual sound level does not change. Mute button results in the mute icon being displayed, but the sound level does not change.

I noticed a thread for a similar problem under XBMC for Windows here, but the only recommended solution is not Linux compatible.

Does anyone have any other ideas?

I am running:
XBMC Live 8.10 from a USB flash drive
Athlon 64 x2 5000+ w/ 2GB RAM
NVidia GeForce 8500

[dan1son]

AC3 and DTS are both unmodified bitstream outputs. XBMC doesn't alter the stream in any way when it's sent to the receiver. This is the normal behavior.

You'll need to change the volume on your receiver. Just as you do with your Cable Box, DVD Player, etc. when using the optical connection.

[miked2024]

AC3 and DTS are both unmodified bitstream outputs. XBMC doesn't alter the stream in any way when it's sent to the receiver. This is the normal behavior.

You'll need to change the volume on your receiver. Just as you do with your Cable Box, DVD Player, etc. when using the optical connection.

Yes, it does. The 3/6/9 buttons on my remote raise/lower/mute the volume on AC3 audio. You may be thinking of the XBOX version which at one time (and may still be the case) was unable to change the volume on AC3/DTS sources.

WillyB, is your default audio output device set correctly in xbmc in the system settings area under Audio Hardware?

[WillyB]

miked2024,
I double checked my settings under Audio Hardware and they were as follows:

Audio Output: Digital
-AC3 Receiver: Enabled
-DTS Receiver: Enabled
Audio Output Device: defaul
Passthrough Output Device: iec958

I played around with the settings a bit and found that I gained volume control if I disabled DTS (** Thank You **). Any suggestions on how I might get it to work with DTS?

Thank you for the help! Volume control without AC3 is a reasonable compromise, but since my DTS receiver is less than a week old I had to at least ask the question.

I should mention that in order to get mkv audio to work I upgraded ALSA (sound driver) to the latest version as described here.

[spiff]

what does passthrough mean? what does changing the volume of a stream mean?

see, not compatible!

[WillyB]

Isn't AC3 a passthrough? Why does volume control work with AC3?

[spiff]

i'm trying to be helpful yes, with a knotch of sarcasm as usual

passthrough = passing the bitstream (= the still-encoded audio) to your receiver. it then handles the decoding.

we cannot amplify a bitstream, we can only amplify the decoded audio. which means that we would have to decode it first, i.e. no passthrough.

if the volume control affects your ac3 streams it means they are not passed through, i.e. you have not enabled 'ac3 capable receiver' in settings.

[WillyB]

Haha, u caught that!

It looks like I was tricked when I thought I had AC3 volume control. My receiver was not detecting a digital signal, but AC3 was enabled:

Audio Output: Digital
-AC3 Receiver: Enabled
-DTS Receiver: Disabled
Audio Output Device: defaul
Passthrough Output Device: iec958

The receiver detects digital audio only when DTS is enabled.

Audio Output: Digital
-AC3 Receiver: Enabled
-DTS Receiver: Enabled
Audio Output Device: defaul
Passthrough Output Device: iec958

I seem to be getting the digital output fine from AC3 sources as long as DTS is enabled, so it's not really an issue for me but I though you might want to know. Bug?

I guess my dream of a one remote world is dead, at least until I'm willing to fork over the cash for a Harmony.

Thanks for your help & patients!

[spiff]

hmm, sounds like something is using the dts setting for everything. bug indeed

[tslayer]

Wasn't there something as reversed DTS/AC3 that was fixed somewhat recently?

Which build are you using? Try latest SVN if you are not using it.

[phi2039]

Wasn't there something as reversed DTS/AC3 that was fixed somewhat recently?

Which build are you using? Try latest SVN if you are not using it.

Yup. See trac ticket: 5884

-C