Audio-Trouble: AC3-Sound on analogue audio output? (1 Viewer)

[red_zebra]

Hello,

is it possible to send digital audio signals (AC3) to the analogue output as well as to the digital (optical) output? My CRT-TV has no digital input, so I have to connect it via chinch to the analogue output on the sound card. And because I don't want to start the Hifi-receiver every time I watch a TV series' episode, I would like to playback also AC3-sound via the televeision's speakers. So, where can I configure, that Mediaportal scales down the AC3-5/6-channel-sound to a stereo-signal which can be sent to the analogue output? Or is there a plugin, which can do this?
In my sound driver there is no such option, and the Realtek-support told me, this option must be configured in the playback-software.

My configuration:
MediaPortal Version: 1.0.2
MediaPortal Skin: X-Factor
Windows Version: Windows XP SP3
CPU Type: AMD 4850e (2 x 2.5 GHz)
HDD: Samsung EcoGreen 1000GB
Memory: 3 x 1024MB DDR2-800 CL5
Motherboard: Gigabyte GA-MA78GM-UD2H
Video Card: Gigabyte ATI Radeon HD2600XT 256MB GDDR3 (passiv)
Video Card Driver: ATI Catalyst v9.8
Sound Card: Realtek ALC 889A HD Audio
Sound Card AC3: optical out
Sound Card Driver: Realtek HD Audio v5.10.00.5286
MPEG2 Video Codec: Cyberlink Video/SP Decoder (PDVD9)
MPEG2 Audio Codec: MPC-MPA Decoder Filter
h.264 Video Codec: MPC Video Decoder
HTPC Case: Inter-Tech HTPC 2008-V
Cooling: 2 x Scythe S-Flex 12cm @ 800RPM
Power Supply: Be Quiet! Pure Power 350W
Remote: Logitech Harmony 555
TV: Samsung CRT (4:3)
TV - HTPC Connection: S-Video

Thank you,
m.

 

[Berns]

red_zebra,

What you want to do is to have your sound card driver switch output channel from SP/Dif to cinch and back, based on what you feel is the best approach at any given moment in time. Is that right?

Your PC at least has 2 outputs, one optical (probably SP/Dif) and one jack stereo. Correct?
I suspect your TV has 2 cinch for sound, one white one red. Correct?

My opinion about your case:
If all the above is correct, then this has little or nothing to do with MP. Nor has it anything to do with AC/3.
It is possible to listen to stereo AC/3 (i.e. 2.0 Dolby Digital) if your speakers are directly connected to an amplifier that converts digital sound to analog speaker output.
Your PC, on its stereo jack, maybe is able to produce AC/3. You will only be able to hear the full digital quality if you hook speakers directly to that jack.
In the best case, you can use your TV amplifier to amplify analog sound that is produced from the jack of your PC.

Before starting to find a solution:
Are you able to control your audio card from within the Realtek control panel to switch between optical output and jack stereo output?

 

[red_zebra]

What you want to do is to have your sound card driver switch output channel from SP/Dif to cinch and back, based on what you feel is the best approach at any given moment in time. Is that right?

No, not really. I have connected my Hifi-amplifier to the SPDIF-port, so I can switch my Hifi on to enjoy full 5.1-sound of DVDs or avi-files with multichannel-AC3-sound. My TV is connected with a jack-cinch-cable to transfer stereo signals to the TV-speakers. What I want is, that the sound of all AC3-files is tranfered to the TV as well as to the Hifi, so I can decide for every playback, if I
1. turn on Hifi and mute the TV to listen to the sound via Hifi or
2. just playback the sound with the TV-speakers and let my Hifi turned off. Therefore the multichannel-sound must be downsampled to stereo and has to be transmitted via the audio jack.

Your PC at least has 2 outputs, one optical (probably SP/Dif) and one jack stereo. Correct?
I suspect your TV has 2 cinch for sound, one white one red. Correct?

yes, completely right.

Your PC, on its stereo jack, maybe is able to produce AC/3. You will only be able to hear the full digital quality if you hook speakers directly to that jack.
In the best case, you can use your TV amplifier to amplify analog sound that is produced from the jack of your PC.

This is the way I am using it at the moment. If there is an analogue signal, it is amplified by the TV and I can use the TV-speakers. But once there is a digital AC3-signal, there is nothing to hear by the TV-speakers and the only way to playback this sound is by switching on the Hifi. It doesn't matter if I switch SPDIF on or off in the sound driver - there is still no signal on the audio jack after switching SPDIF off (so in this case I have no sound at all). And it doesn't matter which audio jack I connect to the TV (there are 4 - front, rear, center/sub and side) - there is no signal on any of them.

Before starting to find a solution:
Are you able to control your audio card from within the Realtek control panel to switch between optical output and jack stereo output?

No. I just can switch on or off SPDIF. But as I mentioned above, there is no difference between switching on and off SPDIF - there is still no signal on audio jack when I play a file with AC3-sound (no matter how many audio-channels the file has).

I hope this explains my problem a bit better. And by the way: Thanks for your help!

 

[kiwijunglist]

It's not possible for direct pass through, but if you decode DTS to DPII or something similar it may work.

Simultaneous SPDIF and Analog audio output. - The Green Button

 

[netexplorer]

Hi,
i use the same configuration as yours and don't want to switch on my receiver all the time. So i have build a small script to switch these settings with my remote.
Follow this >Link< to the german thread.

Regards Netexplorer.

 

[red_zebra]

Great! This is exactly what I was looking for. I will try the script on weekend, so we'll see if it also works with MPA-MPC Codec...


By the way: Meanwhile I found where to configure the 2-channel-downsampling - which was my first problem. For all who have the same problem: (Note: I use SAF Codec Pack) In Start --> Programs --> SAF --> SAF Video Configuration configure, that there is a task menu icon when playing a video file. Then start a video with AC3-sound in WMP or other software (not MP). When playing the video, there is the SAF-task-menu-icon. Right click on this, chosing the AC3-decoder which is used by Mediaportal and there downsampling or SPDIF-passthrough can be configured.