Can AC3 be pass-through and 2-channel encoded at the same time?

[zaldwaik]

Is it possilbe to play AC3 using pass-through to my receiver and, concurrently, convert the same AC3 sound to stereo for output through my sound card headphone jack?

I am trying to use a headphone because I have hearing issues, but at the same time allow others to hear the sound through the speakers. I can do this for 2-channel sound, but not for AC3. All the movies I have have AC3 5.1 sound.

I have looked around for a while, but could not find the answer.

[psycik]

Short answer yes it should be possible. I have my system hooked up so that there is pass through to a receiver (Digital coax) and audio out on the soundcard to 2xrca into a TV.

This means music will come out of the receiver or the TV, and recordings the same. As far an I can recall AC3 (Dolby Digital) based movies will come out of the "tv" (the one with the 2xrca) they are "converted" to stereo. The only movies that don't work are those with a DTS soundtrack

[zaldwaik]

Thanks for the quick reply. Based on your response, you are not getting AC3 to your receiver and out of the sound card at the same time, is that correct? If that is the case, then we have the same setup, which does not really solve my problem.

[psycik]

Ok, I've just confirmed. And no, sorry AC3 doesn't come out of the tv (I thought it did).

I think there are methods of converting an AC3 signal to a stereo on the fly that should allow you to do this though. AC3Filter is the name I've heard about (but never tried). ffdshow would probably also be able to do it.

But what I can confirm that a normal mpeg (say a recording) or an MP3 does come out both sources (which is half your problem).

[zaldwaik]

I tried ffdshow and ac3filter without success. I am wondering if adding second sound card would make it happen?

[psycik]

A thought...what are you pushing the AC3 signal into?? A receiver?? Can you not plug your headphones into the receiver?

[JonnyCam]

So, you want AC3 coming out of both your analog and digital connections. I dont think this is a valid combo, as directshow would be trying to split the audio into 2 different filters.

I have PCM going to my receiver for everything except when I set Ac3 filter to pass the SPDIF through, which means the analog sound stops (on my old system the analog on the TV tried to play the ac3 signal, which ends up with a messy interference type sound)

As for Psycik's suggestion - that would cut the sound of your reciever too - but if you have a monitor out, (prob 2 x RCA) then run an RCA cable from there to your listening position, and convert it back to a headphone socket for you to listen to (therefore, it should be doing the down-sampling for you)

Maybe a set of wireless headphones would be a good idea to stop ugly cables running over the floor.

[zaldwaik]

psycik,
You are right, a receiver. I am using headphones attached to the receiver (wireless) but that stops sound from going to the surround speakers. My objective is to attach my headphones to the sound card output.

JonnyCam,
I am using wirelss headphones. I am not sure what you mean by "monitor out". The only output from the receiver is the headphone jack, which, when used, disables output to all speakers.

I thought about opening up my receiver and attaching a wire to the headphone jack from the inside, but I do not think this will work since it is only enabled when a jack is physically inserted.

[HtV]

My 2cts: If you don't have a monitor-out (It's used when you record stuff from your receiver/amp) you could use the line out to a small extra amp and from there to the headphones.
Or: plug your headphones (well the wireless transmitter) in to he tv, if it has a headphone plugin.

[zaldwaik]

My 2cts: If you don't have a monitor-out (It's used when you record stuff from your receiver/amp) you could use the line out to a small extra amp and from there to the headphones.
Or: plug your headphones (well the wireless transmitter) in to he tv, if it has a headphone plugin.

I assume you mean a line-out from my receiver? That is something I do not have. Line-out from the sound card does not carry sound in AC3- passthru mode with optical cable. In either case, my TV only receives analog sound from my sound card, I do not have a way to route AC3 to it through the receiver.

It sounds like I may have to buy a new receiver, something I am trying to avoid!