[megaxyu]

Hi,

Im new to the forum and apologize in advance if this question was asked before (I have tried the search but yielded no results)


I am running a 9800gtx+ connected with a DVI to HDMI cable to a 42LG70 LCD TV. I am also running a separate 1/8' Jack cable for the audio.


The manual states that the audio input is used for VGA/DVI


When I select the proper HDMI (there are 4 available) input port from the TV screen I get the PC output picture but no sound. If i select a different HDMI input or the VGA input (nothing is connected to any of them) I get the sound but obviously no picture. I have tried switching to a different HDMI port and the same thing keeps happening - Picture shows up with correct HDMI input selected but no sound and vice verse.

 

[Dratheos]

What so you mean you're running a separate cable for the audio? The GTX+ has it's own audio codec so it should be able to output over the DVI to HDMI connection.


Also, what is the default playback device set to?

 

[whiteboy714]



Quote:
Originally Posted by Dratheos /forum/post/16866244


What so you mean you're running a separate cable for the audio? The GTX+ has it's own audio codec so it should be able to output over the DVI to HDMI connection.


Also, what is the default playback device set to?

I'm pretty sure you CAN NOT get sound through DVI. Regardless of the adapter its still begins with DVI, which is only video.


Someone please correct me if I'm wrong.

 

[Dratheos]



Quote:
Originally Posted by whiteboy714 /forum/post/16866425


I'm pretty sure you CAN NOT get sound through DVI. Regardless of the adapter its still begins with DVI, which is only video.


Someone please correct me if I'm wrong.

If you can't, someone had better tell the 10' dvi to hdmi cable I use to hook up my Zotac 9800 GTX (not +, so it has a small wire that has to be hooked up to the spdif header on my mobo) to my HDTV that carries sound.

 

[whiteboy714]



Quote:
Originally Posted by Dratheos /forum/post/16866501


If you can't, someone had better tell the 10' dvi to hdmi cable I use to hook up my Zotac 9800 GTX (not +, so it has a small wire that has to be hooked up to the spdif header on my mobo) to my HDTV that carries sound.

Like I said someone please correct me if I'm wrong. I still don't think you can get sound from the dvi output. But I'm not gonna call you a liar I just wasnt aware of this.

 

[renethx]

None of the current GeForce discrete graphics card has a HD audio controller. But you can still get HDMI audio if you connect SPDIF from the mb onboard audio (or a sound card) to the graphics card's SPDIF connector.

 

[Bigbird999]

FWIW, my trusty old M2AVM HDMI 690G mobo outputs audio and video over HDMI from its DVI port. Discovered by accident, not used, I use VGA. Hard to find much info but DVI has some extra pins which can carry audio signals. Might be something to do with the fact it has an addin HDMI card and onboard HDMI audio.


BB

 

[walford]



Quote:
Originally Posted by whiteboy714 /forum/post/16866584


Like I said someone please correct me if I'm wrong. I still don't think you can get sound from the dvi output. But I'm not gonna call you a liar I just wasnt aware of this.

With HDMI the video and audio signals are multiplexed over the same set of data pins.

Some ATI cards have the capability to multiplex the video and audio over the data pins using a DVI connector. These cards come with a special DVI to HDMI adapter that alters the EDID data from the HDMI connection to tell the card to multiplex the signals over the DVI video data pins and therefore will provide both video and audio over HDMI.

 

[rynowhi]



Quote:
Originally Posted by walford /forum/post/16867585


With HDMI the video and audio signals are multiplexed over the same set of data pins.

Some ATI cards have the capability to multiplex the video and audio over the data pins using a DVI connector. These cards come with a special DVI to HDMI adapter that alters the EDID data from the HDMI connection to tell the card to multiplex the signals over the DVI video data pins and therefore will provide both video and audio over HDMI.

Which includes my onboard hd3200.

 

[megaxyu]

Ok so what I have to do is connect the SPDIF port from the Video Card (If i have one) to the Sound Card and at this point the DVI port from the video card should carry sound ?


I will check to see if I have this port on the video card tonight.


Thanks for all the quick replies

 

[michanecash]

DVI cable do not typically carry audio signals. Even if you have a DVI to HDMI cable, the signal wont be encoded on one end or decoded on the other. Some newer graphics cards can include audio in the TMDS (Transition Minimized Differential Signaling), but if your computer cannot do this or your monitor cannot decode it, it wont work. You will need to get a separate audio cable. I have a DVI input on my sony that I use and it has a red/white audio input designated for it.

 

[walford]



Quote:
Originally Posted by megaxyu /forum/post/16867863


Ok so what I have to do is connect the SPDIF port from the Video Card (If i have one) to the Sound Card and at this point the DVI port from the video card should carry sound ?


I will check to see if I have this port on the video card tonight.


Thanks for all the quick replies

I do not the details for NVIDIA graphic cards or even if there is one. In the case of the ATI cards that can use the special DVI_HDMI adapter there is a sound chip right on the ATI card so no internal cables are required.

 

[whiteboy714]



Quote:
Originally Posted by walford /forum/post/16867585


With HDMI the video and audio signals are multiplexed over the same set of data pins.

Some ATI cards have the capability to multiplex the video and audio over the data pins using a DVI connector. These cards come with a special DVI to HDMI adapter that alters the EDID data from the HDMI connection to tell the card to multiplex the signals over the DVI video data pins and therefore will provide both video and audio over HDMI.

Interesting thank you, learn something new everyday here.

 

[megaxyu]



Quote:
Originally Posted by michanecash /forum/post/16868381


DVI cable do not typically carry audio signals. Even if you have a DVI to HDMI cable, the signal wont be encoded on one end or decoded on the other. Some newer graphics cards can include audio in the TMDS (Transition Minimized Differential Signaling), but if your computer cannot do this or your monitor cannot decode it, it wont work. You will need to get a separate audio cable. I have a DVI input on my sony that I use and it has a red/white audio input designated for it.

I currently have a separate audio cable but the HDMI/DVI input in my TV fails to recognize the fact that it should be looking for sound input through the "1/8 Audio RGB/DVI jack"

 

[walford]

Most HDTVs will only accept stereo audio for use over only one of their HDMI video connections, check your user manual. Also some will not automtically sense that you are using the stereo cables and they have a setting where you tell it.

 

[michanecash]

I have another TV where I just use a DVI to HDMI cable and then I have another cable that goes from a head phone jack to a right and left audio input. It is essentially 2 channel audio. It doesnt sound bad at all and I use it all the time to watch downloaded media. If you are looking to have surround sound, you need to get a computer that supports that type of audio either through HDMI or digital optical audio.

 

[michanecash]

Most TV's with a DVI input will have a setup like this:


(i circled the inputs)

 

[PanamaMike]



Quote:
Originally Posted by megaxyu /forum/post/16869339


I currently have a separate audio cable but the HDMI/DVI input in my TV fails to recognize the fact that it should be looking for sound input through the "1/8 Audio RGB/DVI jack"

The problem you're having might have to do with how your graphics card works. If it thinks it's sending a pseudo HDMI signal via the DVI-to-HDMI you may not be getting audio because the GFX card is trying to send it and switches your source in your system.


When you switch to RGB, it then switches back to send the audio via the 1/8 pin. You may need to look through the graphics card manual to figure that out. One of the joys of HTPC is that it won't allow you to send audio out of two devices simultaneously.


The problem I have is I'd like to be able to switch between my TV HDMI out and my receiver SPDIF out on the fly. Unfortunately the OS only allows one at a time. I have to go the control panel to switch where the audio is going to.

This might help...


Mike

 

[renethx]



Quote:
Originally Posted by Bigbird999 /forum/post/16867565


FWIW, my trusty old M2AVM HDMI 690G mobo outputs audio and video over HDMI from its DVI port. Discovered by accident, not used, I use VGA. Hard to find much info but DVI has some extra pins which can carry audio signals. Might be something to do with the fact it has an addin HDMI card and onboard HDMI audio.

Actually audio signals are interleaved into video signals in HDMI TMDS signals (read this ). So there is no didicated audio pin even in the HDMI connector. As DVI and HDMI pins are in 1-1 correspondence (single-link=Type A, dual-link=Type B), there is no problem in transmitting video/audio TMDS signals over DVI. (You will need a special DVI-HDMI adapter to transmit audio if you use a "discrete" ATI card, however; but the 'extra pins' hypothesis is still wrong.)

 

[Bigbird999]

No special adapter in my case. I just hook a DVI>HDMI cable up to the onboard DVI connector of my 690G mobo (ATIx1250). Plug the HDMI into the TV, et voila, video with sound on my tv speakers. Never sure why or how, it just works. I seem to remember seeing that you can get the same out of the 780G (ATI 3200). I have oine but never tried it. VGA works better for my setup.


BB