Shrill sound when I start a movie. (1 Viewer)

[alamagar]

TV-Server Version: none
MediaPortal Version: 1.0
MediaPortal Skin:
Windows Version: xpsp2
CPU Type: AMD
HDD:
Memory:
Motherboard:
Video Card:
Video Card Driver:
Sound Card:
Sound Card AC3:
Sound Card Driver:
1. TV Card:
1. TV Card Type:
1. TV Card Driver:
2. TV Card:
2. TV Card Type:
2. TV Card Driver:
3. TV Card:
3. TV Card Type:
3. TV Card Driver:
4. TV Card:
4. TV Card Type:
4. TV Card Driver:
MPEG2 Video Codec: ffdshow
MPEG2 Audio Codec: ac3filter
h.264 Video Codec: coreavc
Satelite/CableTV Provider:
HTPC Case:
Cooling:
Power Supply:
Remote:
TV: Panasonic PX70E
TV - HTPC Connection: HDMI via AVR

Each time I start a movie from MediaPortal I hear a brief shrill sound like a snap Electric (over 1 second) through the speakers, which at times is quite annoying and perhaps dangerous for the speakers or the AVR.
The same film launched directly from another viewer (MPC, KMP or zoomplayer) doesn't make that sound.

Can anyone help me?

thank you.

 

[Paranoid Delusion]

If you change your audio filter to ffdshow with ac3 support enabled, do you still get this, you would need graphstudio\graphedit to test this, running MP in windowed mode (alt-enter), play file then connect to remote graph to confirm which codec is being used.

 

[alamagar]

Hello Ray:
If I use ffdshow and unchek AC3 in ffdshow config->output->pass-trough then the shrill sound dissapears. The same if I disable spdif passthrough in AC3filter. The spdif passtrough seems to be the cause.

But there is no shrill sound with the stand alone players with passtrough enabled?
Any workaround?

thank you